JP2005329896A - VEHICLE DRIVE OPERATION ASSISTANCE DEVICE AND VEHICLE WITH VEHICLE DRIVE OPERATION ASSISTANCE DEVICE - Google Patents

Abstract

【Task】
Provided is a vehicle driving assistance device for assisting a driver's driving operation by performing deceleration control and operation reaction force control when the own lane travels a curve.
[Solution]
The controller sets a control target point to be controlled in a curve ahead of the host vehicle, and calculates a target deceleration for operation reaction force control and a target deceleration for braking / driving force control on the control target point. Operation reaction force control is started based on the target deceleration for operation reaction force control, and then braking / driving force control is started based on the target deceleration for braking / driving force control. When braking / driving force control is started, the reaction force control amount that is set based on the target deceleration for the operation reaction force control is gradually reduced, and the operation reaction force control is started from the state where only the operation reaction force control is performed. Smooth transition to the state where force control and braking / driving force control are performed.
[Selection] FIG.

Description

  The present invention relates to a driving operation assisting device for a vehicle that assists a driver's operation.

  When the host vehicle enters a curve, there is known one that decelerates the host vehicle based on the curve information and the vehicle speed (see, for example, Patent Document 1). After the host vehicle enters the curve, this device greatly decelerates the host vehicle as the curve entry degree increases based on the curve entry degree based on the steering amount and the curve information obtained from the navigation system.

Prior art documents related to the present invention include the following.
JP 2003-256999 A

  The above-described device decelerates the host vehicle so that the vehicle can travel at an appropriate vehicle speed. In addition to the vehicle control in such a curve, it is desired to convey the risk related to the curve to the driver in an easy-to-understand manner before entering the curve.

  The vehicle driving assistance device according to the present invention includes a vehicle state detection unit that detects a vehicle state, a road shape detection unit that detects a road shape ahead of the host vehicle, and a detection result by the vehicle state detection unit and the road shape detection unit. The deviation risk calculating means for calculating the risk that the own vehicle deviates from the road ahead, and the braking / driving force for controlling the braking / driving force generated in the own vehicle based on the risk calculated by the deviation risk calculating means An operation reaction force control means for controlling an operation reaction force generated in the driving operation device based on the risk calculated by the control means and the deviation risk calculation means; a braking / driving force control and an operation reaction force by the braking / driving force control means; When the operating state of the braking / driving force control and / or the operating reaction force control changes in the region where the operation reaction force control by the control means is performed together, the braking / driving force control and the operation force control are performed. And a control adjustment means for the reaction force control to control the braking and driving force control means to operate smoothly and the operation reaction force control means.

  The braking / driving force control and the operation reaction force control operate smoothly when the operating state of the braking / driving force control and / or the operation reaction force control changes in an area where both the braking / driving force control and the operation reaction force control are performed. Since each control is adjusted so that the braking / driving force and the operation reaction force fluctuate undesirably, it is possible to suppress the driver from feeling uncomfortable or troublesome.

<< First Embodiment >>
A vehicle operation assistance device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram showing a configuration of a vehicle driving assistance device 1 according to the first embodiment of the present invention, and FIG. 2 is a configuration diagram of a vehicle on which the vehicle driving assistance device 1 is mounted. . In the first embodiment, a case where the vehicle driving assistance device 1 is mounted on a rear wheel drive vehicle equipped with an automatic transmission and a conventional differential will be described as an example.

  First, the configuration of the vehicle driving assistance device 1 will be described. The vehicle driving operation assisting device 1 includes a vehicle speed sensor 10, a steering angle sensor 20, a navigation system 30, an accelerator pedal reaction force control device 60 that controls an operation reaction force generated in an accelerator pedal 62, and a brake pedal 72. A brake pedal reaction force control device 70 that controls the operation reaction force that is generated, a driving force control device 80 that controls the driving force generated in the host vehicle, and a braking force control device 90 that controls the braking force generated in the host vehicle. And a controller 50 for controlling the entire driving operation assisting device 1 for a vehicle.

  The vehicle speed sensor 10 detects the vehicle speed of the host vehicle by measuring the number of rotations of the wheels and the number of rotations on the output side of the transmission, and outputs the detected host vehicle speed to the controller 50. The steering angle sensor 20 is an angle sensor or the like attached in the vicinity of the steering column or the steering wheel 21, detects the rotation of the steering shaft as a steering angle, and outputs it to the controller 50.

  The navigation system 30 is a device that performs route search and route guidance, and includes a GPS (Global Positioning System) for detecting vehicle position information (X0, Y0) and a storage medium that stores map information. . The storage medium is information on the road ahead of which the vehicle is traveling, shape information on the road (eg, radius of a curved road), topographic information such as the gradient of the road, environmental information such as intersections and tunnels, and further traveling Node point information indicating the coordinates of the node points set on the road is held. Here, the node point indicates a travel route on which the vehicle can travel as a point. That is, the node row in which the node points are arranged indicates a straight or curved travel route on which the vehicle travels.

  The navigation system 30 refers to the map information stored in the storage medium based on the position information (X0, Y0) of the host vehicle detected by the GPS, the distance Ln to the node point on the road ahead of the vehicle, and The node system is configured to calculate the node coordinates (Xn, Yn, Ln) composed of the absolute coordinates (Xn, Yjn) of the node point. Node point information) is output to the controller 50.

  The controller 50 includes a CPU and CPU peripheral components such as a ROM and a RAM, and controls the entire vehicle driving assistance device 1. The controller 50 reads the vehicle state such as the host vehicle speed and the steering angle from the vehicle speed sensor 10 and the steering angle sensor 20. Further, node point information of the traveling road ahead of the host vehicle is read from the navigation system 30 to recognize the road shape of the road on which the host vehicle travels.

  And the controller 50 calculates the risk at the time of the own vehicle drive | working based on the information regarding a vehicle state and a road shape. Specifically, a risk related to excess vehicle speed when the host vehicle enters the curve and travels along the curve (hereinafter referred to as corner speed excess risk) is calculated. Based on the corner speed excess risk, the operation reaction force generated in the accelerator pedal 62 and the operation reaction force generated in the brake pedal 72 are controlled. Further, based on the corner speed excess risk, the braking / driving force of the host vehicle is controlled so that the host vehicle does not become overspeed when traveling on a curve.

  Therefore, the controller 50 outputs the command value of the operation reaction force based on the corner speed excess risk to the accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 70, respectively, and the braking / driving force based on the corner speed excess risk. The command value is output to the driving force control device 80 and the braking force control device 90, respectively. Details of these controls will be described later.

  The accelerator pedal reaction force control device 60 controls the torque generated by the servo motor 61 incorporated in the link mechanism of the accelerator pedal 62 in accordance with the reaction force command value input from the controller 50. The servo motor 61 controls the reaction force generated according to the command value from the accelerator pedal operation reaction force control device 60, and can arbitrarily control the pedaling force generated when the driver operates the accelerator pedal 62. . In addition, the reaction force characteristic (normal reaction force characteristic) when the accelerator pedal reaction force control according to the corner speed excess risk is not performed, for example, the pedal reaction force increases in proportion to an increase in the operation amount of the accelerator pedal 62. Is set to This normal reaction force characteristic can be realized by a spring force of a torsion spring (not shown) provided at the center of rotation of the accelerator pedal 62, for example.

  The accelerator pedal 62 is provided with an accelerator pedal stroke sensor 63 that detects the amount of depression (operation amount) of the accelerator pedal 62. The accelerator pedal operation amount detected by the accelerator pedal stroke sensor 63 is output to the controller 50.

  The brake pedal reaction force control device 70 controls the torque generated by the servo motor 71 incorporated in the link mechanism of the brake pedal 72 in accordance with the reaction force command value input from the controller 50. The servo motor 71 controls the reaction force generated according to the command value from the brake pedal reaction force control device 70, and can arbitrarily control the pedal force generated when the driver operates the brake pedal 72. In addition, the reaction force characteristic (normal reaction force characteristic) when the brake pedal reaction force control according to the corner speed excess risk is not performed, for example, the pedal reaction force increases in proportion to an increase in the operation amount of the brake pedal 72. Is set to Here, the reaction force of the brake pedal is controlled by the servo motor 71. However, the present invention is not limited to this. For example, the brake assist force can be generated using oil pressure by computer control.

  The brake pedal stroke sensor 73 detects the operation amount of the brake pedal 72 converted into the rotation angle of the servo motor 71 via the link mechanism. The brake pedal stroke sensor 73 outputs the detected brake pedal operation amount to the controller 50.

  The driving force control device 80 controls the driving force generated in the host vehicle by controlling the operating state of the engine by controlling the throttle opening of a throttle valve (not shown), for example, in response to a command from the controller 50. To do. The driving force control device 80 can also control the driving force by controlling a selected gear ratio of an automatic transmission (not shown) or by controlling the fuel injection amount and ignition timing to the engine.

  The braking force control device 90 can individually control the braking force (braking fluid pressure) applied to the front, rear, left, and right wheels in accordance with a command from the controller 50. The braking force control device 90 includes a brake device 91 provided on the left front wheel of the vehicle, a brake device 92 provided on the right front wheel, a brake device 93 provided on the left rear wheel, and a brake device provided on the right rear wheel. 94 is controlled. Here, the left and right front and rear wheel brake devices 91 to 94 each include a brake disc and a wheel cylinder that frictionally clamps the brake disc by supplying hydraulic pressure and applies a braking force (braking force) to the wheel. The braking force control device 90 individually brakes the wheels by supplying hydraulic pressure to the wheel cylinders of the brake devices 91 to 94, respectively.

  The braking force control device 90 includes actuators corresponding to the respective hydraulic pressure supply systems (each channel) on the front, rear, left and right sides. As the actuator, for example, a proportional solenoid valve is used so that each wheel cylinder hydraulic pressure can be controlled to an arbitrary braking hydraulic pressure. The braking force control device 90 controls the hydraulic pressure supplied to the wheel cylinder of each wheel by adjusting the hydraulic pressure from the master cylinder by operating the brake pedal 72 in accordance with a command from the controller 50.

  The master cylinder hydraulic pressure sensor 95 detects the hydraulic pressure Pm of the master cylinder corresponding to the driver's brake operation, and inputs the detection result to the controller 50.

  Next, the operation of the vehicle driving assistance device 1 according to the first embodiment will be described with reference to the flowchart of FIG. FIG. 3 shows a flowchart of the processing procedure of the driving operation assist control processing in the controller 50 of the first embodiment. This processing content is continuously performed at regular intervals, for example, every 50 msec.

  In step S100, detection signals from the vehicle speed sensor 10, the steering angle sensor 20, the accelerator pedal stroke sensor 62, and the master cylinder hydraulic pressure sensor 95 are input, and driving state data of the host vehicle is read. Here, the running state data includes the host vehicle speed V, the steering angle θ, the accelerator pedal operation amount S, the master cylinder hydraulic pressure Pm, and the like. Furthermore, the position information (X0, Y0) of the own vehicle and the node point information (Xn, Yn, Ln) of each node point ahead of the own vehicle are read from the navigation system 30.

  In step S110, the road condition ahead of the host vehicle is recognized from the driving state data read in step S100. Specifically, the curvature radius Rn of the road at each node point is calculated based on the node point information (Xn, Yn, Ln) acquired in step S100. Below, the calculation method of the curvature radius Rn is demonstrated.

First, the node point information of the n-1st node point from the vehicle position is (Xn-1, Yn-1, Ln-1), and the node point information of the nth node point is (Xn, Yn, Ln). ), Node point information of the (n + 1) th node point is (Xn + 1, Yn + 1, Ln + 1). Then, variables xa, ya, xb, and yb are calculated according to the following (Equation 1).
xa = K · (Xn−Xn-1)
ya = K. (Yn-Yn-1)
xb = K · (Xn + 1−Xn−1)
yb = K · (Yn + 1−Yn−1) (Formula 1)
However, K0 = (Xn−Xn−1) ² + (Yn−Yn−1) ²
K = (Ln−Ln−1) / (Ko) ^1/2

Next, variables XR, YR, Rr, and A are calculated according to the following (Expression 2) based on the variables xa, ya, xb, and yb calculated in (Expression 1).
XR = (Ca · yb−Cb · ya) / A
YR = (Ca · xa−Cb · xb) / A
Rr = XR ² + YR ² (Formula 2)
However, Ca = (xa ² + ya ² ) / 2
Cb = (xb ² + yb ² ) / 2
A = xb · yb−xb · ya

When the variable A calculated in the above (Equation 2) is smaller than 0.01, or when the variable Rr is larger than 4000000 m, the curvature radius Rn of the road is n at the nth node point from the vehicle position. Calculated to be 2000 m. In other cases, the curvature radius Rn is calculated according to the following (Equation 3). The road curvature Rn becomes a negative value when turning left.
Rn = A / | A |. (Rr) ^1/2 (Formula 3)

  Although a method of calculating the curvature radius Rn of the road from the three node point information is shown here, the calculation method is not limited to this. For example, it is possible to calculate a straight line connecting the node points before and after the point where the curvature radius Rn is to be calculated, and calculate the curvature radius Rn based on the slope of the straight line. Further, although the method of reading the coordinates of the node points from the navigation system 30 and calculating the curvature radius Rn based on the read information has been shown, the curvature radius Rn is stored in advance in the navigation system 30 as the node point information. You can also.

  In step S120, a control target point (target node point) that is a target of braking / driving force control and operation reaction force control is calculated from the plurality of node points that have read the node point information in step S100. FIG. 4 shows an example of a node point obtained from the navigation system 30, and FIG. 5 shows a curvature radius Rn corresponding to the node point shown in FIG. FIG. 6 shows an example of a change in the steering angle θ when passing through a curve as shown in FIG. Here, as shown in FIG. 5, among the node points ahead of the host vehicle, the node point at which the radius of curvature Rn calculated in step S110 is minimized and the point closest to the host vehicle position is set as the target. Select as node point.

  Further, if there is a point having the smallest radius of curvature Rn among the node points that are ahead of the selected target node point, that is, far from the vehicle position, that point is also selected as the target node point. Here, a target node point closest to the host vehicle is set as the control target point 1, and a target node point farther from the host vehicle position than the control target point 1 is set as the control target point 2. Note that the control target point 1 corresponds to the node point at the entrance of the curve in the curve as shown in FIG. 4, and the control target point 2 corresponds to the node point of the minimum curvature radius Rn in the curve.

In step S130, the target vehicle speed V0 when traveling the control target point calculated in step S120 is calculated. Specifically, using the curvature radii Rn_1 and Rn_2 of the control target points 1 and 2 and a preset allowable lateral acceleration Yglimit, the target vehicle speed V0_1 at the control target point 1 and the control target point from the following (Equation 4) The target vehicle speed V0_2 at 2 is calculated.
V0_1 = (Yglimit · | Rn_1 |) ^0.5
V0_2 = (Yglimit · | Rn_2 |) ^0.5 (Expression 4)
The allowable lateral acceleration Yglimit is, for example, 0.3G.

In step S140, a target deceleration Xgs at the control target point is calculated. The target deceleration Xgs is a deceleration required for the host vehicle to travel without departing from the curve at the target vehicle speed V0. Specifically, based on the current host vehicle speed V, the inter-vehicle distances Ln_1 and Ln_2 to the control target points 1 and 2 and the target vehicle speeds V0_1 and V0_2 read in step S100, the target deceleration is calculated from the following (Equation 5). Xgs_1 and Xgs_2 are calculated.
Xgs_1 = (V ² −V0_1 ² ) / (2 · Ln_1)
= (V ² −Yglimit · | Rn_1 |) / (2 · Ln_1)
Xgs_2 = (V ² −V0_2 ² ) / (2 · Ln_2)
= (V ² −Yglimit · | Rn_2 |) / (2 · Ln_2) (Formula 5)
The target deceleration Xgs takes a positive value during deceleration.

  FIG. 7 shows the relationship between the vehicle position with respect to the corner and the required deceleration Xgs. As shown in FIG. 7, the required deceleration Xgs increases as the vehicle position approaches the control target point. Here, since the curvature radius Rn_2 of the control target point 2 is smaller than the curvature radius Rn_1 of the control target point 1, the necessary deceleration Xgs_2 with respect to the control target point 2 is calculated to be relatively large.

  In step S150, it is determined whether to start the operation reaction force control. The operation reaction force control is performed based on a corner speed excess risk Rcv described later. Here, based on the target deceleration Xgs calculated in step S140, the operation reaction force control start determination is performed as follows. First, when the operation reaction force control flag flg_rf set in the previous cycle is in a reset state, the target deceleration Xgs corresponding to the current position of the host vehicle calculated in step S140 is equal to or greater than a predetermined threshold value Xgs_warn. Then, the operation reaction force control flag flg_rf is set to 1.

  Further, when the operation reaction force control flag flg_rf set in the previous cycle is set to 1, the operation is performed when the target deceleration Xgs corresponding to the current position of the host vehicle is equal to or greater than a predetermined value (Xgs_warn−Khwarn). The reaction force control flag flg_rf is set to 1. Here, Khwarn is a constant for preventing operation reaction force control start / release hunting, and is set to 0.03 G, for example.

  On the other hand, when the above condition is not satisfied, such as when the target deceleration Xgs corresponding to the current position of the host vehicle is smaller than a predetermined value (Xgs_warn−Khwarn), the operation reaction force control flag flg_rf is reset to 0. The operation reaction force control start determination is made for both the target decelerations Xgs_1 and Xgs_2 calculated for the control target point 1 and the control target point 2.

  In subsequent step S160, the braking / driving force control start determination is performed based on the target deceleration Xgs calculated in step S140 as follows. First, when the braking / driving force control flag flg_dec set in the previous cycle is in a reset state, the target deceleration Xgs corresponding to the current position of the host vehicle calculated in step S140 is equal to or greater than a predetermined threshold value Xgs_start. The braking / driving force control flag flg_dec is set to 1.

  In addition, when the braking / driving force control flag flg_dec set in the previous cycle is set to 1, when the target deceleration Xgs corresponding to the current position of the host vehicle is equal to or greater than a predetermined value (Xgs_start−Kh), The driving force control flag flg_dec is set to 1. Here, Kh is a constant for preventing hunting of braking / driving force control start / release, and an appropriate value is set in advance.

  On the other hand, when the above condition is not satisfied, such as when the target deceleration Xgs corresponding to the current position of the host vehicle is smaller than a predetermined value (Xgs_start−Kh), the braking / driving force control flag flg_dec is reset to 0. The braking / driving force control start determination is performed for both the target decelerations Xgs_1 and Xgs_2 calculated for the control target point 1 and the control target point 2. Further, the threshold values Xgs_warn and Xgs_start used in the determinations in steps S150 and S160 are not limited to fixed values. For example, when the brightness around the vehicle is judged based on the operating state of the headlight, etc., and the driver feels a sense of speed when the surroundings of the vehicle are dark, a variation value that changes according to the brightness may be used. Is possible.

  In step S170, the target deceleration Xgs calculated in step S140 is corrected. Here, for example, the target deceleration Xgs is limited using the threshold value Xgs_start used in the determination of the braking / driving force control in step S160. The target deceleration Xgs subjected to the limit correction is set as a target deceleration correction value Xgs_h. When the target deceleration Xgs does not exceed the threshold value Xgs_start, the target deceleration Xgs is set as it is as the target deceleration correction value Xgs_h.

  In step S180, a risk when the host vehicle travels a curve, that is, a corner speed excess risk Rcv is calculated from the target deceleration Xgs calculated in step S140. FIG. 8 shows the relationship between the target deceleration Xgs and the corner speed excess risk Rcv. As shown in FIG. 8, the corner speed excess risk Rcv increases as the target deceleration Xgs increases. The target deceleration Xgs and corner speed excess risk Rcv both represent the risk that the vehicle will deviate from the front corner due to excess vehicle speed, and the target deceleration Xgs can be used as the corner speed excess risk Rcv as it is. It is.

  In step S190, target braking hydraulic pressures to be supplied to the wheel cylinders of the front and rear, left and right wheel brake devices 91 to 94 are calculated. First, it is determined whether or not the braking / driving force control flag flg_dec set in step S160 is set to 1. When flg_dec = 1, in order to execute the braking / driving force control, the target braking hydraulic pressure Pc is calculated by multiplying the target deceleration correction value Xgs_h calculated in step S170 by a constant Kb determined from the brake specifications. Then, the larger one of the target braking fluid pressure Pc and the master cylinder pressure Pm by the driver's braking operation is set as the front wheel target braking fluid pressure Psf. Further, based on the front-wheel target braking fluid pressure Psf, the rear-wheel target braking fluid pressure Psr is calculated so as to achieve an optimal front-rear braking force distribution.

  After the host vehicle passes the control target point, the target braking hydraulic pressure Pc, that is, the braking / driving force control amount to be generated in the host vehicle is set so that the driver does not feel uncomfortable by suddenly terminating the braking / driving force control. Is gradually reduced to zero. In this case, for example, a change amount limiter in which a limit value is appropriately set is used.

  On the other hand, when the braking / driving force control flag flg_dec is in the reset state, the braking / driving force control is not executed. Therefore, the master cylinder pressure Pm by the driver's braking operation is set as the front-wheel target braking hydraulic pressure Psf, and the rear-wheel target is set so that the optimal front-rear braking force distribution is based on the front-wheel target braking hydraulic pressure Psf. The brake fluid pressure Psr is calculated.

  In subsequent step S200, the driving force generated in the host vehicle is calculated. Specifically, when the braking / driving force control flag flg_dec is set to 1, the target driving torque f (S) is calculated according to the accelerator pedal operation amount S read in step S100. Then, the target driving torque Trqds is calculated by subtracting the braking torque g (Pc) that is predicted to be generated by the target braking hydraulic pressure Pc calculated in step S190 from the target driving torque f (S).

  On the other hand, when the braking / driving force control flag flg_dec is in the reset state, the target drive torque f (S) calculated according to the accelerator pedal operation amount S is set as the target drive torque Trgds as it is.

In step S210, the control amounts of the accelerator pedal reaction force and the brake pedal reaction force are calculated based on the corner speed excess risk Rcv calculated in step S180. First, it is determined whether or not the operation reaction force control flag flg_rf set in step S150 is set to 1. When flg_rf = 1, the operation reaction force control is executed, and therefore the reaction force control amount ΔF is calculated from the following (Equation 6) using the corner speed excess risk Rcv calculated in step S180.
ΔF = K_rf · Rcv (Formula 6)

  Here, K_rf is a gain for converting the corner speed excess risk Rcv to be transmitted to the driver as the reaction force control amount ΔF, and an appropriate value is set in advance. On the other hand, when the operation reaction force control flag flg_rf set in step S150 is in a reset state, the reaction force control amount ΔF is set to 0 because the operation reaction force control is not performed. Further, after the own vehicle passes the control target point, the reaction force control amount ΔF is gradually decreased to 0 so that the operation reaction force control is suddenly terminated and the driver does not feel uncomfortable. In this case, for example, a change amount limiter based on a preset limit value is used.

  In step S220, the reaction force control amount ΔF calculated in step S210 is corrected. Specifically, when the target deceleration Xgs exceeds the threshold value Xgs_start, the reaction force control amount ΔF is limited to a value corresponding to the threshold value Xgs_start. Furthermore, when the operation reaction force control and the braking / driving force control for the control target point 2 are started after the host vehicle passes the control target point 1, the reaction force control amount ΔF after passing the control target point 1 is determined. Reduce the rate of decline. FIG. 9 shows the relationship between the vehicle position relative to the corner, the required deceleration Xgs and the reaction force control amount ΔF.

  As shown in FIG. 9, when the reaction force control amount ΔF is not corrected after passing through the control target point 1, the reaction force control amount ΔF gradually decreases at a predetermined limit value, and the target deceleration Xgs with respect to the control target point 2. As it increases, it begins to increase again. Therefore, when the host vehicle travels a curve, the operation reaction force fluctuates, which may give the driver a feeling of strangeness. Therefore, when the operation reaction force control and the braking / driving force control for the control target point 2 are started after passing through the control target point 1, the limit value of the change amount limiter is decreased. Thereby, as shown in FIG. 10, a decrease in the reaction force control amount ΔF after passing through the control target point 1 is suppressed, and it is possible to smoothly shift to the operation reaction force control for the control target point 2. Of course, when the limit value of the variation limiter is corrected to be small, the limit value can be set to 0.

  In step S230, the target braking hydraulic pressures Psf and Psr calculated in step S190 are output to the braking force control device 90, and the target driving torque Trqds calculated in step S200 is output to the driving force control device 80. The braking force control device 90 supplies hydraulic pressure to the wheel cylinders of the brake devices 91 to 94 of the front, rear, left and right wheels according to the hydraulic pressure command value input from the controller 50, and brakes each wheel individually. The driving force control device 80 adjusts the opening degree of the throttle valve and the like, and controls the driving force generated in the host vehicle.

  In step S240, the reaction force control amount ΔF set in step S210 or step S220 is output to the accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 70, respectively. In response to a command from the controller 50, the accelerator pedal reaction force control device 60 generates a value obtained by adding the reaction force control amount ΔF to the normal reaction force characteristic corresponding to the accelerator pedal operation amount S as the accelerator pedal reaction force. The servo motor 61 is controlled.

  The brake pedal reaction force control device 70 generates a value obtained by subtracting the reaction force control amount ΔF from the normal reaction force characteristic corresponding to the brake pedal operation amount as the brake pedal reaction force in response to a command from the controller 50. Next, the servo motor 71 is controlled. That is, the reaction force control amount ΔF corresponds to the brake assist force, and the driver can easily depress the brake pedal 72 by adding the reaction force control amount ΔF. Thus, the current process is terminated.

The operation of the vehicle driving assistance device 1 according to the first embodiment will be described below with reference to FIGS. 10 and 11. FIG. 11 shows changes in the braking / driving force control amount corresponding to FIG.
As shown in FIG. 11, the braking / driving force control amount starts to increase when the target deceleration Xgs for the control target point 1 exceeds the threshold Xgs_start for starting the braking / driving force control, and is fixed at a value corresponding to the threshold Xgs_start. When the host vehicle passes the control target point 1, the braking / driving force control amount is gradually reduced to 0 by the change amount limiter. Thereafter, when the target deceleration Xgs for the control target point 2 exceeds the threshold value Xgs_start, the braking / driving force control amount starts to increase again and gradually decreases to 0 after the host vehicle passes through the control target point 2.

  On the other hand, as shown in FIG. 10, when the target deceleration Xgs for the control target point 1 exceeds the threshold value Xgs_warn for starting the operation reaction force control, the reaction force control amount ΔF starts to increase. When the target deceleration Xgs exceeds the braking / driving force control start threshold value Xgs_start, the reaction force control amount ΔF is fixed to a value corresponding to the target deceleration correction value Xgs_h limited by the braking / driving force control start threshold value Xgs_start. When the host vehicle passes the control target point 1, the reaction force control amount ΔF gradually decreases by the change amount limiter, but the decrease amount is suppressed in preparation for the operation reaction force control for the control target point 2 that is started thereafter. Thereafter, when the target deceleration Xgs for the control target point 2 increases, the reaction force control amount ΔF increases again and is fixed to a value corresponding to the target deceleration correction value Xgs_h. When the host vehicle passes the control target point 2, the reaction force control amount ΔF is gradually reduced to 0 by the change amount limiter.

  As described above, when the host vehicle enters the curve, the reaction force control and braking / driving force are controlled in accordance with the deceleration Xgs_1 necessary for passing through the curve entrance (control target point 1) without exceeding the vehicle speed. The control is performed, and further, the reaction force control and the braking / driving force control according to the required deceleration Xgs_2 with respect to the point where the radius of curvature Rn on the curve is the minimum (control target point 2) are performed. Accordingly, the host vehicle can be decelerated so as not to reach an excessive vehicle speed that deviates from the curve when traveling on the curve. Further, since the operation reaction force control is performed at a timing earlier than the braking / driving force control, it is possible to notify the driver of the risk related to the curve travel as the operation reaction force before the braking / driving force control is started.

  After passing the control target point 1, the braking / driving force control amount gradually decreases and the braking force generated in the host vehicle decreases, but the decrease in the reaction force control amount ΔF is suppressed. Accordingly, it is possible to suppress the host vehicle from undesirably accelerating after passing through the control target point 1 and smoothly shift to the operation reaction force control and the braking / driving force control with respect to the control target point 2. .

As described above, the following effects can be achieved in the first embodiment described above.
(1) The controller 50 detects the road shape ahead of the host vehicle and calculates the risk that the host vehicle deviates from the road ahead (target deceleration Xgs or corner speed excess risk) based on the vehicle state and road shape. To do. Then, the braking / driving force generated in the host vehicle is controlled based on the calculated risk, and the operation reaction force generated in the driving operation device such as the accelerator pedal 62 and the brake pedal 72 is controlled based on the risk. Thereby, while decelerating the own vehicle so that the own vehicle does not depart from the road ahead, the risk of deviating can be transmitted to the driver as an operation reaction force. Further, in a region where both braking / driving force control and operation reaction force control are performed, the braking / driving force control and operation reaction force control are interlocked when the operating state of the braking / driving force control and / or operation reaction force control changes. Adjust each control to work smoothly. That is, each control is adjusted so that the feeling of deceleration experienced by the driver is smoothly changed by the braking / driving force control and the operation reaction force control. As a result, it is possible to suppress the braking / driving force and the operation reaction force from changing undesirably and giving the driver an uncomfortable feeling and annoyance in a state where both the braking / driving force control and the operation reaction force control are performed.
(2) When the braking / driving force control and the operation reaction force control are finished, the controller 50 determines the decrease rate of the operation reaction force (reaction force control amount ΔF) by the operation reaction force control by the control amount by the braking / driving force control ( The target brake hydraulic pressure Pc) is slower than the rate of decrease. As a result, as shown in FIGS. 10 and 11, when the host vehicle passes the control target point 1, the braking / driving force control amount is rapidly reduced, while the rate of decrease in the reaction force control amount ΔF is suppressed. As a result, when the own vehicle approaches the corner and approaches the point of the minimum radius of curvature in the corner, it is possible to suppress the operation reaction force from greatly fluctuating and causing the driver to feel uncomfortable. Furthermore, even if the reaction force control amount ΔF is suppressed from decreasing, the braking / driving force control amount decreases quickly, so that the driver does not feel an undesirably large deceleration after the vehicle enters the corner. Thus, by setting the rate of decrease in the reaction force control amount ΔF and the rate of decrease in the braking / driving force control amount to be different, a smooth transition is made from the control for the control target point 1 to the control for the control target point 2. can do.
(3) The controller 50 calculates the risk that the host vehicle deviates from the forward curve based on the vehicle state, for example, the host vehicle speed V and the curvature radius Rn of the road ahead of the host vehicle. Specifically, the target vehicle speed V0 when the host vehicle travels a curve is calculated from the radius of curvature Rn and a predetermined allowable lateral acceleration Yglimit, and the host vehicle deviates from the corner from the target vehicle speed V0 and the current host vehicle speed V. Calculate the target deceleration Xgs that is required when traveling without any problems. The corner speed excess risk Rcv calculated from the target deceleration Xgs or the target deceleration Xgs is set as the deviation risk from the curve. As a result, when the host vehicle enters and passes the curve ahead, deceleration control is performed so that the host vehicle does not deviate from the curve, and the driver is informed of the possibility of deviating from the curve as an operation reaction force. Can do.

  In the first embodiment described above, the rate of decrease in the reaction force control amount ΔF is slowed after the host vehicle passes through the control target point 1, but the reaction force control amount ΔF is similarly applied after passing through the control target point 2. It is also possible to slow down the decrease.

<< Second Embodiment >>
A vehicle driving assistance device according to a second embodiment of the present invention will be described with reference to the drawings. The configuration of the vehicular driving assistance device according to the second embodiment is the same as that of the first embodiment shown in FIGS. Here, differences from the first embodiment will be mainly described.

  In the first embodiment described above, the target deceleration Xgs necessary for passing the control target point without exceeding the vehicle speed is set to the same value for the operation reaction force control and the braking / driving force control. In the second embodiment, the target deceleration Xgs_rf in the operation reaction force control and the target deceleration Xgs_dec in the braking / driving force control are set as different values.

  Below, operation | movement of the driving operation assistance apparatus for vehicles by 2nd Embodiment is demonstrated using the flowchart of FIG. FIG. 12 shows a flowchart of the processing procedure of the driving assist control processing in the controller 50 of the second embodiment. This processing content is continuously performed at regular intervals, for example, every 50 msec. The processing in steps S300 to S320 is the same as the processing in steps S100 to S120 of the flowchart shown in FIG.

In step S330, the target vehicle speed V0 when traveling at the control target point 1 and the control target point 2 is calculated for the operation reaction force control and the braking / driving force control, respectively. For the braking / driving force control, a preset allowable lateral acceleration Yglimit is used as in the first embodiment, and for the operation reaction force control, a predetermined allowable lateral acceleration Yglimit_rf smaller than Yglimit is used. The target vehicle speed V0_dec related to braking / driving force control and the target vehicle speed V0_rf related to operation reaction force control are calculated from the following (Equation 7), respectively. In the following (Expression 7), the subscript n represents the control target points 1 and 2.
V0_dec_n = (Yglimit · | Rn_n |) ^0.5
V0_rf_n = (Yglimit_rf · | Rn_n |) ^0.5 (Expression 7)

In subsequent step S340, a target deceleration Xgs at the control target point is calculated. Here, using the target vehicle speeds V0_dec and V0_rf calculated in step S330, the target deceleration Xgs_dec when performing braking / driving force control and the target deceleration Xgs_rf when performing operation reaction force control are expressed by the following (Equation 8). Respectively. In the following (Expression 8), the subscript n represents the control target points 1 and 2.
Xgs_dec_n = (V ² −V0_dec_n ² ) / (2 · Ln_n)
= (V ² −Yglimit · | Rn_n |) / (2 · Ln_n)
^{Xgs_rf_n = (V 2 -V0_rf_n 2)} / (2 · Ln_n)
= (V ² −Yglimit_rf · | Rn_n |) / (2 · Ln_n) (Equation 8)
The target deceleration Xgs takes a positive value during deceleration.

  FIG. 13 shows the relationship between the vehicle position with respect to the corner and the target decelerations Xgs_dec, Xgs_rf. Here, only the target decelerations Xgs_dec and Xgs_rf for the control target point 1 are shown for the sake of simplicity. The target decelerations Xgs_dec and Xgs_rf increase as the host vehicle approaches the control target point 1. However, since the allowable lateral acceleration Yglimit_rf for the operation reaction force control is smaller than the allowable lateral acceleration Yglimit for the braking / driving force control (Yglimit_rf &#60; Yglimit), the target deceleration Xgs_rf in the operation reaction force control as shown in FIG. Is set relatively large.

  In subsequent step S350, as in step S150 of FIG. 3 described above, the operation reaction force control start determination is performed using a predetermined threshold value Xgs_warn. In step S360, as in step S160 of FIG. 3 described above, the start of braking / driving force control is determined using a predetermined threshold value Xgs_start.

  In step S370, the target deceleration Xgs calculated in step S340 is corrected. Here, the target deceleration Xgs_dec in the braking / driving force control is limited by a predetermined value (for example, Xgs_start), and the corrected value is set as the target deceleration correction value Xgs_dec_h.

  In subsequent step S380, the corner speed excess risk Rcv is calculated based on the target deceleration Xgs_rf in the operation reaction force control calculated in step S340. Specifically, the corner speed excess risk Rcv corresponding to the target deceleration Xgs_rf is calculated using the same map as in FIG.

  In step S390, based on the target deceleration correction value Xgs_dec_h calculated in step S370, target braking hydraulic pressures to be supplied to the wheel cylinders of the front and rear left and right wheel brake devices 91 to 94 are calculated. In step S400, the driving force generated in the host vehicle is calculated.

  In step S410, the reaction force control amount ΔF is calculated based on the corner speed excess risk Rcv calculated in step S380. The reaction force control amount ΔF can be calculated from (Equation 6) described above. In the subsequent step S420, the reaction force control amount ΔF calculated in step S410 is corrected. Specifically, as shown in FIG. 14A, when the target deceleration Xgs_dec in the braking / driving force control exceeds the threshold Xgs_start for determining the braking / driving force control, the reaction force control amount ΔF is a value corresponding to the threshold Xgs_start. Limit to. When the host vehicle passes the control target point 1, the reaction force control amount ΔF is gradually reduced by a change amount limiter based on a predetermined limit value.

  Furthermore, when the reaction force control amount ΔF is limited to a value corresponding to the threshold value Xgs_start after the target deceleration Xgs_dec in the braking / driving force control exceeds the threshold value Xgs_start, the reaction force control amount ΔF gradually decreases. Accordingly, as shown in FIG. 14A, the reaction force control amount ΔF peaks at a position where the target deceleration Xgs_dec of the braking / driving force control reaches the threshold value Xgs_start, and then gradually decreases to a value corresponding to the threshold value Xgs_start.

  In step S430, the drive signals calculated in steps S390 and S400 are output to the braking force control device 90 and the driving force control device 80, respectively. In step S440, the reaction force control amount ΔF corrected in step S420 is output to the accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 70, respectively. Thus, the current process is terminated.

  Hereinafter, the operation of the vehicle driving operation assisting apparatus 1 according to the second embodiment will be described with reference to FIGS. FIG. 14B shows a change in the braking / driving force control amount corresponding to FIG. 14A and 14B, only changes in the reaction force control amount ΔF and the braking / driving force control amount with respect to the control target point 1 are shown for the sake of simplicity.

  As shown in FIG. 14B, the braking / driving force control amount starts to increase when the target deceleration Xgs_dec in the braking / driving force control exceeds the threshold value Xgs_start, and is fixed at a value corresponding to the threshold value Xgs_start. When the host vehicle passes the control target point 1, the braking / driving force control amount is gradually reduced by the change amount limiter.

  On the other hand, as shown in FIG. 14A, when the target deceleration Xgs_rf in the operation reaction force control exceeds the threshold value Xgs_warn, the reaction force control amount ΔF starts to increase. When the target deceleration Xgs_dec in the braking / driving force control exceeds the braking / driving force control start threshold value Xgs_start, the reaction force control amount ΔF gradually decreases and is fixed to a value corresponding to the threshold value Xgs_start. When the host vehicle passes the control target point 1, the reaction force control amount ΔF gradually decreases due to the change amount limiter.

  FIGS. 15A and 15B show changes in the reaction force control amount ΔF and the braking / driving force control amount with respect to the control target point 1 and the control target point 2. Changes in the reaction force control amount ΔF and the braking / driving force control amount with respect to the control target point 1 are the same as in FIGS. After passing through the control target point 1, the reaction force control amount ΔF gradually decreases as shown in FIG. Thereafter, the reaction force control amount ΔF increases again as the target deceleration Xgs_rf with respect to the control target point 2 increases. The braking / driving force control amount changes according to the target deceleration Xgs_dec for the control target point 1 and the control target point 2 as shown in FIG.

  Thus, by setting the target deceleration Xgs_dec in the braking / driving force control and the target deceleration Xgs_rf in the operation reaction force control as different values, the braking / driving force control and the operation reaction are prevented so that the vehicle does not deviate from the curve. Force control can be performed effectively.

  In particular, by setting the target deceleration Xgs_rf in the operation reaction force control to be larger than the target deceleration Xgs_dec in the braking / driving force control, the reaction force is greater than when the reaction force control amount ΔF is calculated based on the target deceleration Xgs_dec. A control amount ΔF is generated. Also, since the target deceleration Xgs_dec and the target deceleration Xgs_rf are calculated as different values, when the braking / driving force control starts, the target deceleration Xgs_dec and the target deceleration Xgs_rf are differentiated to the reaction force control amount ΔF. Can have a peak. Thus, by appropriately setting the target deceleration Xgs_dec in the braking / driving force control and the target deceleration Xgs_rf in the operation reaction force control, it is possible to surely inform the driver of the risk related to the curve travel. Also, if the target deceleration Xgs_dec in braking / driving force control exceeds the threshold value Xgs_start, the braking / driving force control amount increases and the reaction force increase amount ΔF decreases, thus preventing the driver from feeling undesirably large deceleration. However, the host vehicle can be appropriately decelerated so that the vehicle can travel without departing from the curve.

  In the second embodiment, as in the first embodiment described above, when the control target point 2 is set after the control target point 1, the control target point 1 is passed. It is also possible to suppress a decrease in the reaction force control amount ΔF.

Thus, in the second embodiment described above, the following operational effects can be obtained in addition to the effects of the first embodiment described above.
(1) When the braking / driving force control starts, the controller 50 gives priority to the braking / driving force control over the operation reaction force control. Specifically, the transmission of the operation reaction force by the operation reaction force control is suppressed, and the braking / driving force by the braking / driving force control is increased to emphasize the feeling of deceleration given to the driver by the deceleration and deceleration of the own vehicle. . Thereby, in the state where the braking / driving force control is started and the operation reaction force control and the braking / driving force control are both performed, it is possible to smoothly shift the control state without giving an excessive feeling of deceleration to the driver.
(2) When the braking / driving force control starts, the controller 50 generates an operation reaction force that causes the driver to recognize that the risk of deviation from the road ahead is increasing. As a result, the driver can be made aware that the risk of departure has increased at the start of braking / driving force control, and subsequent braking / driving force control can be effectively performed.
(3) When the braking / driving force control is started, the controller 50 causes the operation reaction force by the operation reaction force control to reach a peak, and the operation reaction force decreases as the braking / driving force control amount increases by the braking / driving force control. To. Specifically, as shown in FIGS. 14A and 14B, the reaction force control amount ΔF reaches a peak at the deceleration control start point at which the target deceleration Xgs_dec of the braking / driving force control reaches the threshold value Xgs_start, and the braking The reaction force control amount ΔF is corrected so that the reaction force control amount ΔF gradually decreases as the driving force control amount increases. When the braking / driving force control amount gradually increases due to the start of braking / driving force control, if the reaction force control amount ΔF also increases according to the target deceleration Xgs_rf, the driver feels excessive deceleration due to the operating reaction force and braking force. May feel. Therefore, by correcting the reaction force control amount ΔF at the start of braking / driving force control, it is possible to reliably inform the driver of the risk when the host vehicle travels without giving the driver an excessive feeling of deceleration. . Furthermore, it is possible to smoothly shift from a state where only the operation reaction force control is performed to a state where the operation reaction force control and the braking / driving force control are performed.

<< Third Embodiment >>
A vehicle driving assistance device according to a third embodiment of the present invention will be described with reference to the drawings. The configuration of the vehicular driving assistance device according to the third embodiment is the same as that of the first embodiment shown in FIGS. 1 and 2. Here, differences from the above-described second embodiment will be mainly described.

  In the second embodiment, the curvature radius Rn of the road is calculated based on the node point information obtained from the navigation system 30. In the third embodiment, when the reliability of the node point information obtained from the navigation system 30 is low, the curvature radius is estimated based on the steering angle θ by the driver, and the target is determined based on the estimated curvature radius. Calculate the deceleration. Note that the vehicular driving operation assistance apparatus according to the third embodiment further includes an acceleration sensor (not shown) that detects acceleration (lateral acceleration) generated in the left-right direction of the host vehicle.

  Below, operation | movement of the driving operation assistance apparatus for vehicles by 3rd Embodiment is demonstrated. Here, for example, consider a case where the host vehicle enters a curve represented by node points as shown in FIG. The controller 50 sets the control target point 1 corresponding to the curve entrance and the control target point 2 having the minimum curvature radius in the curve, and calculates the target deceleration for each. When the vehicle approaches the control target point 1 at the entrance of the curve, a reaction force control amount ΔF and a braking / driving force control amount corresponding to the control target point 1 are generated as shown in FIGS. Operation reaction force control and braking / driving force control are performed so that the vehicle does not deviate from the curve. When the host vehicle passes the control target point 1, an operation reaction force control and a braking / driving force control for the control target point 2 are performed.

  However, the reliability of the node point information obtained from the navigation system 30 is low when the host vehicle does not perform deceleration suitable for the curve even when the operation reaction force control and the braking / driving force control are performed on the control target point 1. Can be considered. Accordingly, in such a case, the radius of curvature of the road is estimated based on the vehicle state of the host vehicle without using the node point information from the navigation system 30, and the reaction force control and braking / driving are controlled based on the estimated radius of curvature. Do force control.

Accordingly, the curvature radius (estimated curvature radius Rn_est) is estimated based on the vehicle state of the host vehicle, here, the steering angle θ, the yaw rate, the lateral acceleration, and the like by the driver. Then, based on the estimated curvature radius Rn_est, an allowable vehicle speed for traveling so that the host vehicle does not deviate from the curve is calculated. Specifically, the allowable vehicle speed V_limit_dec in the braking / driving force control and the allowable vehicle speed V_limit_rf in the operation reaction force control are calculated according to the following (Equation 9).
V_limit_dec = (Yglimit · | Rn_est |) ^0.5
V_limit_rf = (Yglimit_rf · | Rn_est |) ^0.5 (Expression 9)
In (Equation 9), Yglimit_rf <Yglimit.

Next, an estimated vehicle speed used for calculating the target deceleration Xgs is calculated based on the estimated radius of curvature Rn_est and the current lateral acceleration Yg detected by the acceleration sensor. The estimated vehicle speed V_est is expressed by the following (Equation 10).
V_est = (Yg · | Rn_est |) ^0.5 (Expression 10)

The target deceleration Xgs in the braking / driving force control and the operation reaction force control is expressed as follows using the allowable vehicle speed V_limit calculated from (Equation 9), the estimated vehicle speed V_est calculated from (Equation 10), and the target deceleration distance D_est: Calculate according to equation 11). In (Equation 11), the target deceleration in the braking / driving force control is Xgs_est_dec, and the target deceleration Xgs_est_rf in the operation reaction force control.
Xgs_est_dec = (V_est ² −V_limit_dec ² ) / (2 · D_est)
Xgs_est_rf = (V_est ² −V_limit_rf ² ) / (2 · D_est) (Expression 11)
The target deceleration distance D_est is appropriately set so as to increase as the current vehicle speed V of the host vehicle increases.

  Further, the target deceleration Xgs_est_dec in the braking / driving force control calculated from (Equation 11) is limited by the limit value Xgs_limit, and the corrected value is set as the target deceleration correction value Xgs_dec_h. Here, the limit value Xgs_limit is set so as to increase as the steering angle θ by the driver increases, for example, as shown in FIG.

  The controller 50 calculates the corner speed excess risk Rcv from the target deceleration Xgs_est_rf in the operation reaction force control using the same map as in FIG. 8 described above, and calculates the reaction force control amount ΔF from the above (Equation 6). However, as in the second embodiment, when the target deceleration Xgs_est_dec in the braking / driving force control exceeds the threshold value Xgs_start, the reaction force control amount ΔF gradually decreases and is fixed at a value corresponding to the target deceleration correction value Xgs_dec_h. Is done.

  The operation of the vehicle driving assistance device according to the third embodiment described above will be described with reference to FIGS. The operation reaction force control and the braking / driving force control for the control target point 1 are the same as those in the second embodiment described above. If the host vehicle has not sufficiently decelerated after the host vehicle passes the control target point 1, the curvature radius Rn_est estimated based on the vehicle state is used instead of the control based on the node point information from the navigation system 30. Based on the reaction force control and braking / driving force control.

  As shown in FIG. 17 (a), after the host vehicle passes the control target point 1, the reaction force control amount ΔF gradually decreases and increases with the target deceleration Xgs_est_rf calculated based on the estimated curvature radius Rn_est. Increase again. When the target deceleration Xgs_est_dec in the braking / driving force control exceeds the threshold value Xgs_start, the reaction force control amount ΔF gradually decreases and is fixed at a value corresponding to the target deceleration correction value Xgs_dec_h. At this time, as the steering angle θ by the driver increases, the limit value Xgs_limit increases and the target deceleration correction value Xgs_dec_h also increases, so the reaction force control amount ΔF also increases.

  On the other hand, the braking / driving force control amount gradually increases when the target deceleration Xgs_est_dec exceeds the threshold value Xgs_start as shown in FIG. 17B, and is set to a value corresponding to the target deceleration correction value Xgs_dec_h. The reaction force control amount ΔF and the braking / driving force gradually decrease when the host vehicle exceeds the control target point 2 set based on, for example, node point information obtained from the navigation system 30.

Thus, in the third embodiment described above, in addition to the effects of the first and second embodiments described above, the following operational effects can be achieved.
The controller 50 estimates the curvature radius Rn_est based on the vehicle state such as the steering angle θ, the yaw rate, and the lateral acceleration, and performs braking / driving force control and operation reaction force control based on the estimated curvature radius Rn_est. Thereby, even when the reliability of the node point information obtained from the navigation system 30 is low, the braking / driving force control and the operation reaction force control can be reliably performed. Further, as shown in FIGS. 17A and 17B, the reaction force control amount ΔF and the braking / driving force control amount are corrected according to the steering angle θ by the driver. As a result, for example, when driving on a tight curve, a larger deceleration is generated to prevent deviation from the curve, and a large operation reaction force promotes the driver's attention and shift to deceleration operation. it can.

  Even when the radius of curvature Rn is calculated based on the node point information by the navigation system 30, the target deceleration limit value Xgs_limit can be set according to the steering angle θ according to FIG.

<< Fourth Embodiment >>
A vehicle operation assistance device according to a fourth embodiment of the present invention will be described with reference to the drawings. The configuration of the vehicle driving operation assisting device according to the fourth embodiment is the same as that of the first embodiment shown in FIGS. 1 and 2. Here, differences from the above-described first embodiment will be mainly described.

  In the fourth embodiment, the threshold value Xgs_start of the target deceleration Xgs_de for starting the braking / driving force control is changed according to the traveling state of the host vehicle. Specifically, when it is detected that the curve into which the host vehicle enters is within an intersection, the threshold value Xgs_start is set so as to delay the start of braking / driving force control. Further, when the start of the braking / driving force control is delayed, the start of the operation reaction force control is advanced.

  Hereinafter, how the reaction force control and the braking / driving force control are performed in the fourth embodiment will be described with reference to FIG. FIG. 18 shows a flowchart of the processing procedure of the driving assist control processing in the controller 50 of the fourth embodiment. This processing content is continuously performed at regular intervals, for example, every 50 msec.

  The processing in steps S500 and S510 is the same as the processing in steps S100 and S110 of the flowchart shown in FIG. When node point information is read from the navigation system 30 in step S500, information such as road width, road type, presence or absence of intersections and tunnels, and entry-prohibited roads, which are additional information of node points, are also read.

  In step S520, one branch road on the travel route is selected as a control target route. The control target path selected here is a path that is a target (target) for the operation reaction force control and the braking / driving force control. In the fourth embodiment, it is assumed that an intersection is detected. Here, one branch path is selected as a control target path from a plurality of branch paths that pass through or form the intersection. .

  Specifically, for example, when the driver designates one branch road as the travel route of the host vehicle in advance, the designated branch road is selected as the control target route. If the driver does not designate one branch path, one branch path is selected as a control target path with reference to the curvature radius Rn at each node point calculated in step S510. For example, a branch path having the maximum curvature radius Rn is selected.

  In step S530, it is determined whether or not the branch path (control target path) selected in step S520 is a T-shaped intersection. Specifically, for example, based on the information of the intersection type added to the node point information in the selected branch road, it is determined whether or not the branch road is in the T-shaped intersection.

  Even when the intersection shape is different and formally not a T-shaped intersection, it can be determined that the intersection is a T-shaped intersection when it is substantially regarded as a T-shaped intersection. For example, when the driver has set a travel route in advance and makes a right or left turn at an intersection within the set travel route, such as a crossing intersection, or when a straight road at an intersection (for example, a crossing intersection) cannot enter a one-way street Since the vehicle enters substantially like a T-shaped intersection, it may be determined as a T-shaped intersection.

  When a T-shaped intersection is detected in this way, TRUE is given to the intersection flag flg_cr for the corner (node point) in the intersection (flg_cr = TRUE). On the other hand, if it is not a T-shaped intersection, FALSE is assigned to the intersection flag flg_cr for the corner (node point) (flg_cr = FALSE). Here, the node point which becomes an intersection corner is a node point used in the intersection determination, for example, a node point to which an intersection attribute is given. FIG. 19 shows an example of a T-shaped intersection that can be acquired from a node point using the navigation system 30. As shown in FIG. 19, one node point in the intersection is an intersection corner.

  In step S540, it is determined whether or not the driver can easily recognize the T-shaped intersection detected in step S530 from the vehicle position. Specifically, based on the traveling environment before the T-shaped intersection, it is determined whether the T-shaped intersection is easily recognized from the vehicle position. Therefore, the first evaluation value Sr is the ease of recognizing the T-shaped intersection based on the shape of the road connected to the T-shaped intersection, that is, the road shape in front of the currently running intersection. The second evaluation value Sf is the ease of recognizing a T-shaped intersection based on the presence or absence of existing equipment, and the third evaluation value So is the ease of recognition of a T-shaped intersection based on the preceding vehicle. Set as follows.

(1) Setting of the first evaluation value Sr
A first evaluation value Sr is set based on the road shape before the T-shaped intersection. Here, the road shape before the T-shaped intersection is obtained based on the node point before the T-shaped intersection as shown in FIG. When the road shape in front of the T-shaped intersection is “straight line”, “slow curve”, “medium curve”, “steep curve”, the evaluation values Sr are “1”, “0.8”, “0.5”, “0. 2 ”. That is, the first evaluation value Sr is set to a larger value as the curve becomes gentler, and the first evaluation value Sr is set to a larger value so that the driver can easily recognize the forward T-shaped intersection from the vehicle position. To do.

  Here, for example, “straight line”, “slow curve”, “medium curve”, and “steep curve” are distinguished by the length of the curve connected to the T-shaped intersection and the integrated turning angle of the curve. For example, the curve is steeper as the length of the curve is longer or the cumulative turning angle is larger. It is also possible to distinguish the curve type based on the minimum curvature radius Rn of the curvature radii Rn of the node points of the curve connected to the T-shaped intersection (node points excluding the node point selected as the T-shaped intersection). it can.

(2) Setting of second evaluation value Sf
A second evaluation value Sf is set based on equipment existing on the road in front of the T-shaped intersection (hereinafter referred to as road incidental equipment). Specifically, the second evaluation value Sf is set to a smaller value so that it is considered difficult for the driver to recognize the front T-shaped intersection from the own vehicle position in relation to the road incidental facility in front of the T-shaped intersection. Set.

  For example, when there is no traffic light 301 as shown in FIG. 21 at the T-shaped intersection, the second evaluation value Sf is set to 0.5. Also, as shown in FIG. 22, when the tunnel 302 is in front of the T-shaped intersection, the second evaluation value Sf is set to 0.5. Even when there is a tunnel before the T-shaped intersection, the second evaluation value Sf can be reset to 1 if the tunnel can be exited sufficiently before entering the intersection. The traffic light is actually equipment installed at the intersection. However, when attention is paid to the recognition of the intersection by the driver, the traffic light can be regarded as road incidental equipment existing on the road in front of the intersection.

(3) Setting of Third Evaluation Value So A detector (not shown) such as a laser radar or a millimeter wave radar detects the presence / absence of a preceding vehicle, the inter-vehicle distance to the preceding vehicle, the size of the preceding vehicle, and the like. If the detected preceding vehicle is about the size of a bus or a truck and blocks the field of view of the host vehicle, as shown in FIG. 23, according to the inter-vehicle time THW between the host vehicle 100 and the preceding vehicle 200. A third evaluation value So is set. For example, when the inter-vehicle time THW is greater than 5 sec, the third evaluation value So = 1, when the inter-vehicle time THW is 3 to 5 sec, the third evaluation value So = 0.6, and the inter-vehicle time THW is less than 3 sec Sets the third evaluation value So = 0.2.

  Further, if the size of the preceding vehicle 200 is such that it does not block the field of view of the driver of the host vehicle, the third evaluation value So is set to 1. Further, the third evaluation value So is set to 1 even when there is no preceding vehicle. Note that the third evaluation value So can be set continuously according to the inter-vehicle time THW between the host vehicle and the preceding vehicle. In this case, the third evaluation value So is set to increase as the inter-vehicle time THW increases.

From the first to third evaluation values Sr, Sf, and So set as described above, a comprehensive evaluation value St is obtained by the following (Equation 12).
St = Sr / Sf / So (Formula 12)
The comprehensive evaluation value St calculated from (Equation 12) is a value indicating the ease of recognizing the T-shaped intersection based on the vehicle position, and varies between 0 and 1. That is, when the traveling environment of the host vehicle is comprehensively determined and the driver can easily recognize the forward T-shaped intersection from the position of the host vehicle, the total evaluation value St is a large value.

  In subsequent step S550, a control target point (target node point) to be subjected to braking / driving force control and operation reaction force control is calculated from the plurality of node points read in the node point information in step S500. Here, a node point having the smallest curvature radius Rn is selected as the target node point among the node points to which the flag indicating the T-shaped intersection is given and the node points before and after the node point.

In step S560, the target vehicle speed V0 when traveling the control target point calculated in step S550 is calculated. The target vehicle speed V0 can be calculated from the following (Equation 13) using the curvature radius Rn of the control target point and a preset allowable lateral acceleration Yglimit (for example, 0.3 G).
V0 = (Yglimit · | Rn |) ^0.5 (Expression 13)

In step S570, the target deceleration Xgs at the control target point is calculated according to the following (Equation 14) using the host vehicle speed V and the distance Ln to the control target point.
Xgs = (V ² −V 0 ² ) / (2 · Ln)
= (V ² −Yglimit · | Rn |) / (2 · Ln) (Expression 14)
The target deceleration Xgs takes a positive value during deceleration.

  In the subsequent step S580, a threshold value Xgs_start used for determination of braking / driving force control start and a threshold value Xgs_warn used for determination of operation reaction force control start are set. Specifically, when a T-shaped intersection is detected in step S530 (flg_cr = TRUE), the braking / driving force control start determination threshold value Xgs_start is set as follows.

First, the first judgment allowable value Xgs_max1 is calculated from the following (Expression 15) using the comprehensive evaluation value St of the ease of recognizing the T-shaped intersection calculated in step S540.
Xgs_max1 = Xgs_norm + Xgs_tup · St (Expression 15)
Here, Xgs_norm is a normal setting value for determining the operation start timing of normal braking / driving force control, and corresponds to the threshold value Xgs_start used in the first embodiment. Xgs_norm is, for example, 0.1G. Xgs_tup is a reference value for changing the setting by detecting the T-shaped intersection, and is set to 0.1 G, for example.

Then, the first determination allowable value Xgs_max1 calculated from (Equation 15) is set as the braking / driving force control start determination threshold value Xgs_start (Xgs_start = Xgs_max1).
Further, using the distance Ln between the control target point and the host vehicle and the host vehicle speed V, the arrival time Tln is calculated from (Equation 16) below.
Tln = Ln / V (Equation 16)

When the arrival time Tln calculated from (Equation 16) is equal to or less than a predetermined value, the second determination allowable value Xgs_max2 corresponding to the arrival time Tln is set. Then, the larger one of the first allowable determination value Xgs_max1 and the second allowable determination value Xgs_max2 is set as the braking / driving force control start determination threshold value Xgs_start from the following (Equation 17).
Xgs_start = max (Xgs_max1, Xgs_max2) (Expression 17)

  From the above, for example, when the first determination allowable value Xgs_max1 is set as the braking / driving force control start determination threshold value Xgs_start, the braking / driving force control start determination threshold value Xgs_start corresponds to the comprehensive evaluation value St of the ease of recognizing the T-shaped intersection. Change. Therefore, the braking / driving force control start determination threshold value Xgs_start becomes a larger value as the driver can easily recognize the front T-shaped intersection from the vehicle position.

  When a T-shaped intersection is not detected (flg_cr = FALSE), the normal setting value Xgs_norm is set as the braking / driving force control start determination threshold value Xgs_start.

  Further, using the braking / driving force control start determination threshold value Xgs_start calculated from (Expression 15) or (Expression 17), the operation reaction force control start determination threshold value Xgs_warn is set as follows. Here, the braking / driving force control start determination threshold value when the T-shaped intersection is not detected is described as Xgs_start (= Xgs_norm), and the braking / driving force control start determination threshold value when the T-shaped intersection is detected is described as Xgs_start_aft.

  As shown in FIG. 24, when the braking / driving force control start determination threshold value Xgs_start is corrected to Xgs_start_aft, the time from when the braking / driving force control is started until the host vehicle passes the control target point (deceleration control time b) Becomes shorter. Therefore, when the deceleration control time b is shortened, that is, when the start timing of the braking / driving force control is delayed, the operation reaction force control start determination threshold value Xgs_warn is decreased to advance the operation reaction force control start timing.

  Specifically, as shown in FIG. 25, as the deceleration control time b becomes shorter, the time (reaction force control time a) from the start of the operation reaction force control to the start of the braking / driving force control becomes longer. Set. The reaction force control time a is a time predicted until the target deceleration Xgs increases from Xgs_warn to Xgs_start_aft. Thereby, although the deceleration control time b is shortened, the reaction force control time a is extended, and the start timing of the operation reaction force control is advanced. In FIG. 24, the operation reaction force control start determination threshold when the T-shaped intersection is not detected is Xgs_warn, and the operation reaction force control start determination threshold set in accordance with the correction of the braking / driving force control start determination threshold Xgs_start is Xgs_warn_aft. .

  The reaction force control amount ΔF when starting the operation reaction force control changes as shown in FIG. 26 according to the change in the operation reaction force control start determination threshold value Xgs_warn. That is, the operation reaction force control start timing is earlier as the operation reaction force control start determination threshold value Xgs_warn is smaller, but the generated reaction force control amount ΔF is small, so that the driver is not bothered.

  The braking / driving force control start determination threshold value Xgs_start (or Xgs_start_aft) and the operation reaction force control start determination threshold value Xgs_warn (or Xgs_warn_aft) are set such that the deceleration control time b and the reaction force control time a do not exceed predetermined values, for example, 4 sec. Set to.

  Thus, after setting the braking / driving force control start determination threshold value Xgs_start and the operation reaction force control start determination threshold value Xgs_warn in step S580, the process proceeds to step S590.

  In step S590, based on the target deceleration Xgs calculated in step S570 and the operation reaction force control start determination threshold value Xgs_warn calculated in step S580, the operation reaction force control start determination is performed in the same manner as in step S150 of the flowchart of FIG. . In the subsequent step S600, the braking / driving force control start determination is performed based on the target deceleration Xgs calculated in step S570 and the braking / driving force control start determination threshold value Xgs_start calculated in step S580 as in step S160 of FIG.

  In step S610, the target deceleration Xgs calculated in step S570 is corrected. Here, for example, the target deceleration Xgs is limited using the braking / driving force control start determination threshold value Xgs_start calculated in step S580, and the target deceleration correction value Xgs_h is calculated. When the target deceleration Xgs does not exceed the braking / driving force control start determination threshold value Xgs_start, the target deceleration Xgs is set as it is as the target deceleration correction value Xgs_h.

  The subsequent processing in steps S620 to S680 is the same as the processing in steps S180 to S240 in FIG.

-Modification of the fourth embodiment-
When a T-shaped intersection is detected in front of the host vehicle, the braking / driving force control start determination threshold value Xgs_start can be set to be small. Specifically, as shown in FIG. 27, the threshold value Xgs_start_aft is set to a value smaller than the normal setting value Xgs_start. In this case, since the deceleration control time b becomes longer, the reaction force control time a is shortened according to the relationship of FIG. In this case as well, the deceleration control time b and the reaction force control time a are set so as not to exceed predetermined values (for example, 4 seconds). When the threshold value Xgs_start is set to a value smaller than the normal set value Xgs_norm, the target deceleration Xgs is limited by the corrected threshold value Xgs_start_aft.

  Also, not only when a T-shaped intersection is detected in front of the host vehicle, but also when there is a preceding vehicle that has not started decelerating when the host vehicle enters the curve, the start timing of the braking / driving force control and the operation reaction force control The start timing can be changed.

Thus, in the fourth embodiment described above, the following operational effects can be achieved in addition to the effects of the first to third embodiments described above.
The controller 50 adjusts the start timing of the braking / driving force control and the operation reaction force control based on the traveling situation around the host vehicle. Specifically, the braking / driving force control start determination threshold value Xgs_start is changed according to the traveling state, and the deceleration control time b from when the target deceleration Xgs exceeds the threshold value Xgs_start until the host vehicle passes the control target point is determined. The operation reaction force control start determination threshold value Xgs_warn is changed. For example, as shown in FIG. 24, when the threshold value Xgs_start is made larger than the normal value Xgs_norm, the threshold value Xgs_warn is made smaller than the normal value. Thereby, when the threshold value Xgs_start becomes large and the start timing of the braking / driving force control is delayed, the start timing of the operation reaction force control is advanced. As a result, braking / driving force control can be started without a sense of incongruity while transmitting the risk of departure to the driver from an early stage. In addition, the braking / driving force control amount generated by the braking / driving force control increases as the threshold value Xgs_start increases, but the operation reaction force control starts at an early timing and gradually increases the reaction force control amount ΔF. The operating state of the control can be shifted without giving a strange feeling to the person.

  On the other hand, as shown in FIG. 27, when the braking / driving force control start determination threshold value Xgs_start is smaller than the normal value Xgs_norm, the operation reaction force control start determination threshold value Xgs_warn is increased. Thereby, when the start timing of the operation reaction force control is late, the braking / driving force control is promptly started, and a deceleration is provided so that the host vehicle does not deviate from the curve.

  In the first to fourth embodiments described above, the accelerator pedal 62 and the brake pedal 72 are used as the driving operation devices, and the accelerator pedal reaction force control and the brake pedal reaction force control are performed according to the risk of departure. However, the present invention is not limited to this, and either one of the accelerator pedal reaction force control and the brake pedal reaction force control can be performed.

  In the first to fourth embodiments described above, the case where the host vehicle enters a corner represented by a node point as shown in FIG. 4 as an example, the control target point 1 at the corner entrance and the minimum in the corner Control reaction point control and braking / driving force control were performed by setting a control target point 2 which is a point having a radius of curvature. However, the present invention is not limited to this, and it is of course possible to set one control target point at a certain corner or to set three or more control target points.

  In the first to fourth embodiments described above, the vehicle speed sensor 10 is used as the vehicle state detecting means, the navigation system 30, the controller 50, and the steering angle sensor 20 are used as the road shape detecting means, and the deviation risk calculating means is used. A controller 50 was used. Further, the controller 50, the driving force control device 80 and the braking force control device 80 are used as the braking / driving force control means, and the controller 50, the accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 70 are used as the operation reaction force control means. The controller 50 was used as the control adjustment means. Further, the navigation system 30 was used as the traveling state detection means, and the controller 50 was used as the timing adjustment means. However, the present invention is not limited to these, and it is possible to acquire the curvature radius of the road by road-to-vehicle communication as the road shape detecting means. It is also possible to use a small CCD camera or the like that images the front area of the host vehicle as the traveling state detection means.

1 is a system diagram of a vehicle driving assistance device according to a first embodiment of the present invention. The block diagram of the vehicle carrying the driving operation assistance apparatus for vehicles shown in FIG. The flowchart which shows the process sequence of the driving operation assistance control program in 1st Embodiment. The figure which shows an example of the some node point obtained from a navigation system. The figure which shows the curvature radius corresponding to each node point shown in FIG. The figure which shows the steering angle corresponding to the curve shown in FIG. The figure which shows the relationship between the own vehicle position with respect to a curve, and target deceleration. The figure which shows the relationship between target deceleration and a corner excess risk. The figure which shows the relationship between the own vehicle position with respect to a curve, and the reaction force control amount before correction | amendment. The figure which shows the relationship between the own vehicle position with respect to a curve, and the reaction force control amount after correction | amendment. The figure which shows the relationship between the own vehicle position with respect to a curve, and braking / driving force control amount. The flowchart which shows the process sequence of the driving operation assistance control program in 2nd Embodiment. The figure which shows the target deceleration in the operation reaction force control with respect to the control object point 1, and braking / driving force control. (A) (b) The figure which each shows the relationship between the own vehicle position with respect to a curve, reaction force control amount, and braking / driving force control amount. (A) (b) The figure which each shows the relationship between the own vehicle position with respect to a curve, reaction force control amount, and braking / driving force control amount. The figure which shows the relationship between a steering angle and the limit value of target deceleration. (A) (b) The figure which each shows the relationship between the own vehicle position with respect to a curve, reaction force control amount, and braking / driving force control amount. The flowchart which shows the process sequence of the driving operation assistance control program in 4th Embodiment. The figure which shows an example of the node point information containing the T-shaped intersection obtained from a navigation system. The figure which shows an example of the node point information containing the T-shaped intersection obtained from a navigation system. The figure which shows an example of the node point information containing the T-shaped intersection obtained from a navigation system. The figure which shows an example of the node point information containing the T-shaped intersection obtained from a navigation system. The figure which shows an example of the node point information containing the T-shaped intersection obtained from a navigation system. The figure which shows the relationship between the own vehicle position with respect to the curve when adjusting deceleration control time and reaction force control time, reaction force control amount, and braking / driving force control amount. The figure which shows the relationship between deceleration control time and reaction force control time. The figure which shows the relationship between the operation reaction force control start judgment threshold value and reaction force control amount. The figure which shows the relationship between the own vehicle position with respect to the curve when adjusting deceleration control time and reaction force control time, reaction force control amount, and braking / driving force control amount.

Explanation of symbols

10: Vehicle speed sensor 20: Steering angle sensor 30: Navigation system 50: Controller 60: Accelerator pedal reaction force control device 70: Brake pedal reaction force control device 80: Driving force control device 90: Braking force control devices 91-94: Front / rear, left / right Wheel brake device 62: accelerator pedal 72: brake pedal 95: master cylinder hydraulic pressure sensor

Claims (8)

Vehicle state detection means for detecting the vehicle state;
Road shape detection means for detecting the road shape ahead of the host vehicle;
Deviation risk calculation means for calculating a risk that the host vehicle deviates from a road ahead based on detection results by the vehicle state detection means and the road shape detection means;
Braking / driving force control means for controlling braking / driving force generated in the host vehicle based on the risk calculated by the deviation risk calculating means;
Based on the risk calculated by the deviation risk calculation means, an operation reaction force control means for controlling an operation reaction force generated in the driving operation device;
When an operating state of the braking / driving force control and / or the operation reaction force control changes in a region where both the braking / driving force control by the braking / driving force control unit and the operation reaction force control by the operation reaction force control unit are performed. And a control adjusting means for controlling the braking / driving force control means and the operation reaction force control means so that the braking / driving force control and the operation reaction force control operate smoothly. Operation assisting device. The vehicle driving assistance device according to claim 1,
When the braking / driving force control is started, the control adjustment unit controls the braking / driving force control unit and the operation reaction force control unit so as not to emphasize the operation reaction force control with respect to the braking / driving force control. A driving operation assisting device for a vehicle. The vehicle driving assistance device according to claim 1,
The control adjusting means controls the operation reaction force control means so as to generate an operation reaction force that makes the driver recognize that the risk is rising when the braking / driving force control starts. A driving operation assisting device for a vehicle. The vehicle driving assistance device according to claim 3,
When the braking / driving force control starts, the control adjusting means has a peak of the operating reaction force in the operating reaction force control, and the operating reaction force decreases as the control amount by the braking / driving force control increases. As described above, the vehicle driving operation assisting device controls the operation reaction force control means. The vehicle driving assistance device according to claim 1,
When the braking / driving force control and the operation reaction force control are finished, the control adjusting means sets the operation reaction force decreasing speed by the operation reaction force control to a control amount decreasing speed by the braking / driving force control. A driving operation assisting device for a vehicle, characterized by slowing down the vehicle. In the driving assistance device for a vehicle according to any one of claims 1 to 5,
The departure risk calculation means calculates the risk that the host vehicle deviates from a forward curve based on the vehicle state and a curvature radius of the front road detected by the road shape detection means. A driving operation assisting device for a vehicle. The vehicle driving assistance device according to claim 1,
A traveling state detecting means for detecting a traveling state around the host vehicle;
A vehicle driving operation assisting device further comprising timing adjusting means for adjusting start timings of the braking / driving force control and the operation reaction force control based on a detection result by the traveling state detecting means.   A vehicle comprising the vehicular driving assist device according to any one of claims 1 to 7.

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