JP2006248335A - Vehicle running control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle running control device capable of performing an automatic switchover from low-speed follow-up control to high-speed follow-up control. <P>SOLUTION: The vehicle running control device comprises a low-speed follow-up control means, a high-speed follow-up control means for including a speed zone in which a control start permissible speed zone is overlapped with a control speed zone of the low-speed follow-up control means, a control execution determining means for determining whether or not the low-speed follow-up control means executes its controlling, a speed detecting means for detecting speed of a vehicle, a speed determining means for determining whether or not the speed of the vehicle is within the control start permissible speed zone of the high-speed follow-up control means, and a prediction means for predicting running condition of an preceding vehicle. When the speed is within the control start permissible speed zone of the high-speed follow-up means while executing the control of the low-speed follow-up control means, the vehicle running control device can switch its control from the low-speed follow-up control means to the high-speed follow-up control means if predicted that the preceding vehicle runs at the speed based on the control of the high-speed follow-up control means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle travel control device that controls a travel state of a vehicle to follow a preceding vehicle.

  In order to reduce the driving load on the driver, various vehicle travel control devices that provide driving assistance have been developed. Some vehicle travel control devices perform vehicle speed control to follow a preceding vehicle. Such follow-up control includes high-speed follow-up control that provides support during high-speed travel on an expressway and low-speed follow-up control that provides support during low-speed travel in a traffic jam. In the high-speed tracking control, the vehicle speed control is normally performed so as to maintain the vehicle speed set by the driver, and the vehicle speed control is performed so as to follow the preceding vehicle when there is a preceding vehicle. On the other hand, in the low-speed tracking control, the vehicle speed control is performed so that the preceding vehicle is tracked below a predetermined vehicle speed.

In the case of a device that performs both high-speed tracking control and low-speed tracking control, when switching from high-speed tracking control to low-speed tracking control or switching from low-speed tracking control to high-speed tracking control, the driver switches the mode switch or each control. Use the ON / OFF switch. In this case, the control start vehicle speed and the control end vehicle speed are set for the two controls, respectively. In the case of the high-speed tracking control, the control can be started at a speed higher than the control startup vehicle speed. It becomes a controllable state by (refer patent document 1).
JP 2002-240591 A

  The situation when switching from the low-speed tracking control to the high-speed tracking control is usually when the traffic jam is resolved and the preceding vehicle is accelerating. At that time, the driver wants to follow the preceding vehicle continuously regardless of the control end vehicle speed or the control start vehicle speed of each follow-up control. However, in the case of the conventional device, the driver needs to determine whether the traffic congestion has been resolved, to check the control end vehicle speed or control start vehicle speed of each tracking control, and to start the high speed tracking control. Therefore, in spite of performing similar follow-up control, various troublesome operations are necessary for the driver, and the burden is great.

  Then, this invention makes it a subject to provide the vehicle travel control apparatus which enables automatic switching from low-speed tracking control to high-speed tracking control.

  A vehicle travel control device according to the present invention is a vehicle travel control device that controls the travel state of a vehicle in order to follow a preceding vehicle, wherein the low-speed follow-up control means and the control start permission vehicle speed region are low-speed follow-up control means. High-speed follow-up control means including a vehicle speed region that overlaps the control vehicle speed region, control execution determination means for judging whether or not control by the low-speed follow-up control means is being executed, vehicle speed detection means for detecting vehicle speed, vehicle speed A vehicle speed determination unit that determines whether or not the vehicle speed detected by the detection unit is within a control start permission vehicle speed region of the high-speed tracking control unit; and a prediction unit that predicts the traveling state of the preceding vehicle, and the low-speed tracking control unit When the control is being executed and the vehicle speed is within the control start permission vehicle speed range of the high-speed tracking control means, the traveling state of the preceding vehicle is predicted to travel at the vehicle speed when the control by the high-speed tracking control means is performed. If, and switches from the control by the low-speed following control means the control of the high-speed follow-up control means.

  The vehicle travel control device includes low-speed tracking control means for performing tracking control on the preceding vehicle on the low speed side and high-speed tracking control means for performing tracking control on the preceding vehicle on the high speed side. In the vehicle travel control device, the control start permission vehicle speed region, which is a vehicle speed region in which the control by the high-speed follow-up control means can be started, is set to overlap the control vehicle speed region of the low-speed follow-up control means. Therefore, in order to switch from the control by the low-speed tracking control means to the control by the high-speed tracking control means, it is not necessary to increase the vehicle speed to a vehicle speed higher than the upper limit vehicle speed in the control vehicle speed region of the low-speed tracking control means. Switching is possible even during control by the control means. In the vehicle travel control device, it is determined by the control execution determination means whether or not the control by the low-speed follow-up control means is being executed. In the vehicle travel control device, the vehicle speed is detected by the vehicle speed detection means, and it is determined by the vehicle speed determination means whether or not the detected vehicle speed is within the control start permission vehicle speed region of the high-speed tracking control means. Further, in the vehicle travel control device, the future travel state (for example, vehicle speed, acceleration) of the preceding vehicle is predicted by the prediction means. In the vehicle travel control device, the vehicle speed is within the control start permission vehicle speed region of the high-speed follow-up control means during the control by the low-speed follow-up control means, and the traveling state of the preceding vehicle is controlled by the high-speed follow-up control means. When it is predicted that the vehicle will travel at the vehicle speed at the time of performing, the control is switched from the control by the low-speed tracking control means to the control by the high-speed tracking control means. In other words, when the vehicle speed condition that can activate the high-speed tracking control means is satisfied during the control by the low-speed tracking control means, the preceding vehicle can sufficiently perform the high-speed tracking control by the high-speed tracking control means. When it is predicted that the vehicle speed can be achieved, it can be determined that the traveling state on the low speed side such as traffic congestion has shifted to the traveling state on the high speed side, so the apparatus side switches to the high speed tracking control means. As described above, in the vehicle travel control device, it is possible to automatically switch from the control by the low-speed tracking control means to the control by the high-speed tracking control means. No driver work is required. For this reason, the burden on the driver is reduced, and usability for the follow-up control is improved.

  A vehicle travel control device according to the present invention is a vehicle travel control device that controls the travel state of a vehicle in order to follow a preceding vehicle, wherein the low-speed follow-up control means and the control start permission vehicle speed region are low-speed follow-up control means. High-speed follow-up control means including a vehicle speed region that overlaps the control vehicle speed region, control execution determination means for judging whether or not control by the low-speed follow-up control means is being executed, vehicle speed detection means for detecting vehicle speed, vehicle speed A vehicle speed determining means for determining whether or not the vehicle speed detected by the detecting means is within a control start permission vehicle speed region of the high speed follow-up control means; and an acquisition means for acquiring the traveling environment information of the vehicle; Low when the vehicle is running and the vehicle speed is within the control start permission vehicle speed range of the high-speed tracking control means and the vehicle driving environment is capable of traveling at the vehicle speed when performing control by the high-speed tracking control means. And switches to control by the high-speed follow-up control unit from control by use follow-up control means.

  The vehicle travel control device includes a low-speed follow-up control unit, a high-speed follow-up control unit, a control execution determination unit, a vehicle speed detection unit, and a vehicle speed determination unit similar to the vehicle travel control device described above. Instead, it has acquisition means. In the vehicle travel control device, the travel environment information of the vehicle is acquired by the acquisition means. The traveling environment information of the vehicle is information that can determine whether the vehicle can travel on the high speed side, and is, for example, the type of road on which the vehicle is traveling and traffic jam information. In the vehicle travel control device, the vehicle speed is within the control start permission vehicle speed range of the high-speed follow-up control means while the control by the low-speed follow-up control means is being executed, and the traveling environment of the host vehicle is controlled by the high-speed follow-up control means In the case of an environment where the vehicle can travel at the vehicle speed, the control is switched from the control by the low-speed tracking control means to the control by the high-speed tracking control means. In other words, when the vehicle speed condition that allows the high-speed tracking control means to be activated during the control by the low-speed tracking control means is satisfied, the type of road on which the host vehicle is currently traveling, the state of the road, etc. When the vehicle is in an environment where it is possible to run at a vehicle speed that allows sufficient follow-up control on the high speed side by the control means, it is assumed that the driving state on the low speed side such as traffic congestion has shifted to the high speed side running state. Since it can be determined, the apparatus side switches to the high-speed tracking control means. As described above, in the vehicle travel control device, it is possible to automatically switch from the control by the low-speed tracking control means to the control by the high-speed tracking control means, eliminating the troublesome work at the time of switching, and reducing the burden on the driver. In addition, usability for tracking control is improved.

  In the vehicle travel control device of the present invention, the acquisition means acquires information on whether or not the vehicle is traveling on an automobile exclusive road, and when the vehicle is traveling on an automobile exclusive road, the acquisition means uses the low-speed tracking control means. It is preferable to switch from control to control by high-speed follow-up control means.

  In this vehicle travel control device, information on whether or not the vehicle is traveling on an automobile exclusive road is acquired by the acquisition means. In the vehicle travel control device, if the vehicle speed is within the control start permission vehicle speed range of the high-speed tracking control means while the control by the low-speed tracking control means is being executed, and the traveling road is an automobile-only road, the low-speed tracking is performed. The control is switched from the control by the control means to the control by the high-speed follow-up control means. In other words, if the road on which the vehicle is currently traveling is a road that can be driven at high speed when the vehicle speed condition that can activate the high speed tracking control means is satisfied during the control by the low speed tracking control means, Since it can be determined that the traveling state on the low speed side has shifted to the traveling state on the high speed side, the apparatus switches to the high-speed tracking control means on the apparatus side. Automobile roads are roads that are used only for automobiles, such as expressways, various toll roads, and motorways for general national roads. The road is suitable for control by the control means.

  According to the present invention, automatic switching from low-speed tracking control to high-speed tracking control is possible, and the burden on the driver is reduced.

  Hereinafter, an embodiment of a vehicle travel control device according to the present invention will be described with reference to the drawings.

  In the present embodiment, the vehicle travel control device according to the present invention is applied to a vehicle speed control device having a low-speed tracking control function and a high-speed tracking control function. The vehicle speed control device according to the present embodiment has a low-speed follow-up startable vehicle speed region that is a startable vehicle speed region and a low-speed follow-up control vehicle speed region that is a controllable vehicle speed region for the low-speed follow-up control function. The follow-up control function has a high-speed follow-up startable vehicle speed region that is a startable vehicle speed region and a high-speed follow-up control vehicle speed region that is a controllable vehicle speed region.

  With reference to FIG.1 and FIG.2, the vehicle speed control apparatus 1 is demonstrated. FIG. 1 is a configuration diagram of a vehicle speed control device according to the present embodiment. FIG. 2 is a diagram showing the relationship between the control vehicle speed region and the startable vehicle speed region in the low-speed tracking control function and the high-speed low-speed tracking function of the vehicle speed control device of FIG.

  The vehicle speed control device 1 controls the brake hydraulic pressure and / or the throttle opening to control the vehicle speed during the control by the low speed tracking control function or the control by the high speed tracking control function. In particular, the vehicle speed control device 1 performs automatic switching from control by the low-speed tracking control function to control by the high-speed tracking control function in order to reduce the burden on the driver. The vehicle speed control device 1 includes a laser sensor 2, a yaw rate sensor 3, a vehicle speed sensor 4, a brake switch 5, an accelerator opening sensor 6, a low speed tracking control switch 7, a high speed tracking control switch 8, a brake actuator 9, a throttle actuator 10, A buzzer 11, a display 12, and an ECU [Electronic Control Unit] 13 are provided, and various types of information are acquired from a navigation device NE connected via an in-vehicle LAN [Local Area Network].

  In this embodiment, the high-speed tracking control function corresponds to the high-speed tracking control means described in the claims, the low-speed tracking control function corresponds to the low-speed tracking control means described in the claims, and the vehicle speed The sensor 4 corresponds to vehicle speed detection means described in the claims, the ECU 13 corresponds to control execution determination means, vehicle speed determination means, and prediction means described in the claims, and the ECU 13 and the in-vehicle LAN are claims. It corresponds to the acquisition means described in.

  The laser sensor 2 is a sensor that detects a distance to an object by irradiating a laser beam forward and receiving a laser beam reflected and returned from the object. The laser sensor 2 transmits the detected value to the ECU 13 as a laser signal. The yaw rate sensor 3 is a sensor that detects the yaw rate acting on the vehicle. The yaw rate sensor 3 transmits the detected value as a yaw rate signal to the ECU 13. The vehicle speed sensor 4 is a wheel speed sensor that detects the rotational speed of the wheel. The vehicle speed sensor 4 transmits the rotation speed as a vehicle speed signal to the ECU 13. Although the vehicle speed is estimated based on the detection value of the vehicle speed sensor 4, other vehicle speed sensors such as a sensor for detecting the rotation speed of the transmission may be used in addition to the vehicle speed sensor 4.

  The brake switch 5 is a switch that detects whether or not the brake pedal has been depressed. The brake switch 5 transmits to the ECU 13 a brake signal in which an ON signal is set when the brake pedal is depressed and an OFF signal is set when the brake pedal is not depressed. The accelerator opening sensor 6 is a sensor that detects the opening of the accelerator pedal. The accelerator opening sensor 6 transmits the detected value to the ECU 13 as an accelerator opening signal.

  The low-speed tracking control switch 7 is a driver operation switch for starting / stopping the low-speed tracking control function. The low-speed tracking control switch 7 transmits a low-speed switch signal indicating start or stop to the ECU 13. The high-speed tracking control switch 8 is a driver operation switch for starting / stopping the high-speed tracking control function. The high-speed tracking control switch 8 transmits a high-speed switch signal indicating start or stop to the ECU 13. In the low-speed tracking control switch 7, when the control is switched to the control using the high-speed tracking control function during the control using the low-speed tracking control function, the switch state automatically changes from the activated state to the stopped state. Further, in each of the follow-up control switches 7 and 8, the switch state is automatically changed from the activated state to the stopped state when the control is automatically ended during the control by each follow-up control function.

  The brake actuator 9 is an actuator that adjusts the brake hydraulic pressure of the wheel cylinder. The brake actuator 9 operates according to the target hydraulic pressure signal from the ECU 13 and adjusts the brake hydraulic pressure of the wheel cylinder. The throttle actuator 10 is an actuator that adjusts the opening of the throttle valve. The throttle actuator 10 operates according to a target throttle opening signal from the ECU 13 to adjust the opening of the throttle valve.

  When the buzzer 11 receives the buzzer signal from the ECU 13, it outputs a buzzer sound when the buzzer signal is an ON signal and stops outputting the buzzer sound when the buzzer signal is an OFF signal. When receiving an image signal from the ECU 13, the display 12 displays an image corresponding to the image signal.

  The navigation device NE is a system that displays the current position and traveling direction of a vehicle on a map, searches for a route to a destination set by a driver, and provides guidance according to the searched route. The navigation device NE holds map information, and the map information includes type information for each road. Therefore, the navigation device NE has the type information of the road on which the vehicle is currently traveling. In addition, the navigation device NE uses the VICS [Vehicle Information and Communication System] to incorporate traffic jam information, which is infrastructure information from outside the vehicle, and has traffic jam information on the road that is currently running. In response to the acquisition request from the ECU 13, the navigation device NE provides the ECU 13 with the type information and the traffic jam information of the currently traveling road.

  The ECU 13 is an electronic control unit including a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], and the like. The ECU 13 activates each follow-up control function when the driver performs a start-up operation on each of the switches 7 and 8 in a state where the follow-up control function can be activated. In particular, the ECU 13 automatically switches to the high-speed tracking control function when the automatic switching condition is satisfied during the control by the low-speed tracking control function. Further, the ECU 13 terminates each follow-up control function when the driver performs a stop operation on each switch 7 or 8 during the control by each follow-up control function, or satisfies the termination condition of each follow-up control function. If this happens, each tracking control function is automatically terminated. The ECU 13 takes in various signals from the various sensors 2, 3, and 4, sets various control amounts based on the various signals during control by the following control functions, and controls the brake actuator 9 and the throttle actuator 10.

  With reference to FIG. 2, the vehicle speed region set in the ECU 13 will be described. In the vehicle speed area on the high speed side, the vehicle speed area where the high speed tracking activation is possible and the high speed tracking control vehicle speed area are set in the same vehicle speed area. A low-speed tracking control vehicle speed region is set in the low-speed side vehicle speed region. The lower limit vehicle speed in the high-speed follow-up startable vehicle speed region is set to a vehicle speed lower than the upper limit vehicle speed in the low-speed follow-up control vehicle speed region, and the low-speed side of the high-speed follow-up startable vehicle speed region wraps around the high-speed side of the low-speed follow-up control vehicle speed region. Therefore, it is possible to switch from the low-speed follow-up control function to the high-speed follow-up control function in the wrapping vehicle speed region. A low-speed tracking startable vehicle speed region is set on the low-speed side of the low-speed tracking control vehicle speed region. The upper limit vehicle speed in the low-speed tracking startable vehicle speed region is set to a vehicle speed sufficiently lower than the lower limit vehicle speed in the high-speed tracking control vehicle speed region, and the low-speed tracking startable vehicle speed region and the high-speed tracking control vehicle speed region do not wrap. Therefore, continuous switching from the high-speed tracking control function to the low-speed tracking control function is not possible. Further, an acceleration prohibited vehicle speed region is set from the upper limit vehicle speed in the low-speed tracking control vehicle speed region to a vehicle speed region that is higher by a predetermined vehicle speed. In the acceleration prohibited vehicle speed region, the entire region is overlapped with the vehicle speed region in which high-speed follow-up activation is possible. The acceleration-prohibited vehicle speed region is a vehicle speed region in which automatic acceleration by control cannot be performed during control by the low-speed tracking control function.

  The ECU 13 calculates the vehicle speed of the host vehicle based on the vehicle speed signal from the vehicle speed sensor 4. Further, the ECU 13 calculates the turning direction of the host vehicle based on the yaw rate signal from the yaw rate sensor 3. Then, the ECU 13 considers the turning direction of the host vehicle, and determines the presence or absence of a forward vehicle (preceding vehicle) traveling in the same lane as the host vehicle based on the laser signal from the laser sensor 2. If there is, the inter-vehicle distance and relative speed with the vehicle are calculated. Further, the ECU 13 calculates the vehicle speed and acceleration of the preceding vehicle from the relative speed between the vehicle speed of the host vehicle and the preceding vehicle when there is a preceding vehicle (particularly when automatic switching condition determination is performed), and the preceding vehicle The vehicle speed (predicted vehicle speed) after a predetermined time of the preceding vehicle is calculated from the vehicle speed and acceleration. The predetermined time is a time enough to determine whether or not the preceding vehicle can continue high speed travel.

  Further, when the automatic switching condition determination is performed, the ECU 13 transmits a request signal to the navigation device NE via the in-vehicle LAN, and obtains the type information and traffic jam information of the road that is currently running from the navigation device NE. A response signal including is received. The road type information may be information on at least a highway or other roads, but may be detailed information such as national roads, prefectural roads, municipal roads, highways, and toll roads other than highways. The traffic jam information may be at least information on whether or not it is near the traffic jam resolution position, but may be detailed information such as information indicating a traffic jam section near the current location and the current location.

  The ECU 13 activates the high-speed tracking control function when a high-speed switch signal indicating activation is received from the high-speed tracking control switch 8 when the vehicle speed is within the vehicle speed range where high-speed tracking activation is possible. During the control by the high-speed tracking control function, the ECU 13 generates image data indicating that the control by the high-speed tracking control function is being performed, and transmits the image signal to the display 12.

  The ECU 13 activates the low-speed tracking control function when a low-speed switch signal indicating activation is received from the low-speed tracking control switch 7 when the host vehicle speed is within the vehicle speed range where low-speed tracking activation is possible and there is a preceding vehicle. Incidentally, when the control by the high-speed tracking control function is being performed, the low-speed tracking control function does not enter a startable state. During control by the low-speed tracking control function, the ECU 13 generates image data indicating that control by the low-speed tracking control function is being performed, and transmits the image signal to the display 12.

  The ECU 13 determines whether or not the automatic switching condition is satisfied when a preceding vehicle is present during control by the low-speed tracking control function. When the automatic switching condition is satisfied, the ECU 13 automatically activates the high-speed tracking control function and reduces the speed. The tracking control function is automatically terminated (that is, the low-speed tracking control function is automatically switched to the high-speed tracking control function). There are four automatic switching conditions, and the automatic switching condition is satisfied only when all four conditions are satisfied. In the case of automatic switching, the ECU 13 generates image data indicating automatic switching from the low-speed tracking control function to the high-speed tracking control function, transmits the image signal to the display 12, and sends the buzzer signal of the ON signal to the buzzer 11. Send.

  The first condition is that the host vehicle speed is equal to or higher than the upper limit vehicle speed in the low-speed tracking control vehicle speed region. The starting condition for the high-speed tracking control function is that the vehicle speed is within the vehicle speed range where high-speed tracking can be started. One. It should be noted that by determining the upper limit vehicle speed in the low-speed tracking control vehicle speed region, which is higher than the lower limit vehicle speed in the high-speed tracking startable vehicle speed region, there is a high degree of accuracy that the vehicle can run under the control by the high-speed tracking control function. The possibility of falling below the lower limit vehicle speed in the high-speed tracking control vehicle speed region in a short time is very low.

  The second condition is that the current road is a highway. Since general roads have signals and intersections, it is difficult to continue high-speed driving, and there is a high possibility that deceleration from high-speed driving to low-speed driving is frequently repeated. However, highways usually allow high-speed driving to continue, and there are few situations in which high-speed driving and low-speed driving are frequently repeated. Therefore, when traveling on a highway, the vehicle is in an environment where it can travel at a vehicle speed within the high-speed tracking control vehicle speed region.

  The third condition is that the current position is in the vicinity of the congestion elimination position as infrastructure information. In the vicinity of the congestion elimination position, it is possible to shift from low speed running to high speed running, and in particular, in the case of an expressway, high speed running can be continued. Therefore, when the vehicle is traveling near the congestion elimination position, the vehicle can travel at a vehicle speed within the high-speed tracking control vehicle speed region.

  The fourth condition is that the predicted vehicle speed of the preceding vehicle is higher than the vehicle speed threshold. The vehicle speed threshold is a vehicle speed sufficiently higher than the upper limit vehicle speed in the low-speed tracking control vehicle speed region. If it is predicted that the preceding vehicle is running near the upper limit vehicle speed in the low-speed tracking control vehicle speed range or below the upper vehicle speed from the present time, the preceding vehicle cannot be accelerated and the congestion has not been resolved. Probability is high. However, if it is predicted that the preceding vehicle is traveling at a vehicle speed that is sufficiently higher than the upper limit vehicle speed in the low-speed tracking control vehicle speed range, the preceding vehicle is accelerating, and high-speed traveling is continued from the present time. It is highly possible. Therefore, when the predicted vehicle speed of the preceding vehicle is higher than the vehicle speed threshold, the preceding vehicle is predicted to travel at a vehicle speed within the high-speed tracking control vehicle speed region.

  The ECU 13 automatically terminates the high-speed tracking control function when the vehicle speed falls below the lower limit vehicle speed in the high-speed tracking startable vehicle speed area during the control by the high-speed tracking control function. Further, when the ECU 13 receives a brake signal indicating an ON signal from the brake switch 5 or receives an accelerator opening signal other than fully closed from the accelerator opening sensor 6 during the control by the high-speed tracking control function, the ECU 13 The tracking control function is automatically terminated. When the high-speed tracking control function is automatically terminated, the ECU 13 generates image data indicating that the control by the high-speed tracking control function is automatically terminated, transmits the image signal to the display 12, and generates an ON signal buzzer signal. Transmit to the buzzer 11. Further, the ECU 13 terminates the high-speed tracking control function when a high-speed switch signal indicating stop is received from the high-speed tracking control switch 8 during the control by the high-speed tracking control function.

  The ECU 13 automatically terminates the low speed tracking control function when there is no preceding vehicle during the control by the low speed tracking control function. Further, in the ECU 13, during the control by the low-speed tracking control function, when the host vehicle speed is equal to or higher than the upper limit vehicle speed in the low-speed tracking control vehicle speed area (the lower limit vehicle speed in the acceleration prohibited vehicle speed area) (when the first condition of the automatic switching condition is satisfied) ), The low-speed tracking control function is automatically terminated when the inter-vehicle distance with the preceding vehicle is equal to or greater than the distance threshold when any of the second to fourth conditions of the automatic switching condition is not satisfied. The distance threshold is set in advance through experiments, simulations, and the like, and a long distance that cannot follow the preceding vehicle is set. Further, the ECU 13 automatically ends the low-speed tracking control function when a brake signal indicating an ON signal is received from the brake switch 5 during the control by the low-speed tracking control function. Further, the ECU 13 accelerates according to the accelerator operation by the driver during the control by the low-speed tracking control function, and automatically terminates the low-speed tracking control function when the own vehicle speed becomes equal to or higher than the upper limit vehicle speed in the acceleration prohibited vehicle speed region. When the low-speed tracking control function is automatically terminated, the ECU 13 generates image data indicating that the control by the low-speed tracking control function is automatically terminated, transmits the image signal to the display 12, and generates an ON signal buzzer signal. Transmit to the buzzer 11. Further, the ECU 13 terminates the low-speed tracking control function when a low-speed switch signal indicating stop is received from the low-speed tracking control switch 7 during the control by the low-speed tracking control function. During the control by the low-speed tracking control function, the vehicle speed exceeds the upper limit vehicle speed in the low-speed tracking control vehicle speed range because the preceding vehicle travels above the maximum vehicle speed in the low-speed tracking control vehicle speed range, A case where the upper limit vehicle speed of the region is maintained and a case where the vehicle accelerates according to the accelerator operation by the driver and the host vehicle is traveling at a vehicle speed within the acceleration prohibited vehicle speed region.

  A case where the high-speed tracking control function is activated will be described. The ECU 13 controls the brake actuator 9 or the throttle actuator 10 so as to maintain the vehicle speed set by the driver when there is no preceding vehicle during control by the high-speed tracking control function. The set vehicle speed may be the vehicle speed when the driver performs the starting operation with the high-speed tracking control switch 8 or may be provided in vehicle speed setting means such as a vehicle speed setting lever and set by the driver using the vehicle speed setting means. Good. The ECU 13 normally sets the target throttle opening so as to achieve the set vehicle speed, and transmits a target throttle opening signal set according to the target throttle opening to the throttle actuator 10. Further, the ECU 13 sets a target brake hydraulic pressure when the host vehicle speed exceeds the set vehicle speed on a downhill or the like, and transmits a target hydraulic pressure signal set according to the target brake hydraulic pressure to the brake actuator 9.

  The ECU 13 controls the brake actuator 9 or the throttle actuator 10 so as to follow the preceding vehicle while ensuring the high-speed inter-vehicle distance when the preceding vehicle exists during the control by the high-speed following control function. The high-speed inter-vehicle distance is set in advance by experiments or simulations, and the longer the vehicle speed is, the longer the distance is set. In the ECU 13, when the inter-vehicle distance with the preceding vehicle is less than the high-speed inter-vehicle distance, the target brake hydraulic pressure is set, and the target hydraulic pressure signal set according to the target brake hydraulic pressure is transmitted to the brake actuator 9. Further, the ECU 13 sets a target throttle opening when the inter-vehicle distance with the preceding vehicle is equal to or greater than the high-speed inter-vehicle distance, and transmits a target throttle opening signal set according to the target throttle opening to the throttle actuator 10. . Therefore, the vehicle automatically decelerates when the preceding vehicle decelerates, and automatically accelerates when the preceding vehicle accelerates.

  A case where the low-speed tracking control function is activated will be described. The ECU 13 controls the brake actuator 9 or the throttle actuator 10 so as to follow the preceding vehicle while ensuring the low-speed inter-vehicle distance during the control by the low-speed tracking control function. The low-speed inter-vehicle distance is set in advance by experiments, simulations, and the like. The lower the vehicle speed, the shorter the distance is set, which is shorter than the high-speed inter-vehicle distance. In addition, the specific control with respect to the brake actuator 9 or the throttle actuator 10 in the follow-up control is the same control as the follow-up control described in the high-speed follow-up control function.

  The ECU 13 maintains the upper limit vehicle speed in the low-speed tracking control vehicle speed area (= the lower limit vehicle speed in the acceleration-inhibited vehicle speed area) when the vehicle speed of the preceding vehicle exceeds the upper limit vehicle speed in the low-speed tracking control vehicle speed area during the control by the low-speed tracking control function. In this manner, the brake actuator 9 or the throttle actuator 10 is controlled. In addition, the specific control with respect to the brake actuator 9 or the throttle actuator 10 at the time of vehicle speed maintenance control is the same control as the vehicle speed maintenance control demonstrated by the high-speed tracking control function.

  Note that the ECU 13 determines that the vehicle speed has fallen below the upper limit vehicle speed in the low-speed tracking startable vehicle speed area when the host vehicle speed is below the upper limit vehicle speed in the low-speed tracking startable vehicle speed area when the low-speed tracking control function is not started. The image data to be shown may be generated and the image signal may be transmitted to the display 12 and the buzzer signal of the ON signal may be transmitted to the buzzer 11. In this way, by notifying the driver with the image display and the buzzer, the driver can recognize that the low-speed tracking control function is in the startable vehicle speed region.

  Further, in the ECU 13, when the own vehicle speed is equal to or higher than the upper limit vehicle speed in the low-speed tracking control vehicle speed area during the control by the low-speed tracking control function, any one of the second condition to the fourth condition of the automatic switching condition is not satisfied. (In other words, when the start condition of the high-speed tracking control function is satisfied but automatic switching cannot be performed), image data indicating that the vehicle speed exceeds the upper limit vehicle speed in the low-speed tracking control vehicle speed region is generated, and the image signal is transmitted to the display 12 In addition, the buzzer signal of the ON signal may be transmitted to the buzzer 11. Alternatively, when the host vehicle speed is equal to or higher than the lower limit vehicle speed in the high speed tracking control vehicle speed area, and not to the upper limit vehicle speed in the low speed tracking control vehicle speed area, the vehicle speed exceeds the lower limit vehicle speed in the high speed tracking control vehicle speed area. Image data indicating this may be generated, and the image signal may be transmitted to the display 12 and the buzzer signal of the ON signal may be transmitted to the buzzer 11. By notifying the driver with the image display and the buzzer in this way, the driver can recognize that the high-speed tracking control function is in a vehicle speed region that can be activated even during the control by the low-speed tracking control function. Leave the decision to switch to the high-speed tracking control function.

  With reference to FIG. 1 and FIG. 2, the operation at the time of automatic switching from the low-speed tracking control function to the high-speed tracking control function in the vehicle speed control device 1 will be described along the flowchart of FIG. FIG. 3 is a flowchart showing an operation at the time of automatic switching from the low-speed tracking control function to the high-speed tracking control function in the vehicle speed control device of FIG.

  The ECU 13 determines the turning direction of the vehicle based on the yaw rate signal from the yaw rate sensor 3. Then, the ECU 13 considers the turning direction, determines the presence or absence of a preceding vehicle based on the laser signal from the laser sensor 2, and calculates the inter-vehicle distance and relative speed with the preceding vehicle. Further, the EUU 13 calculates the host vehicle speed based on the vehicle speed signal from the vehicle speed sensor 4.

  When the preceding vehicle travels at a low speed due to traffic jam and the own vehicle falls below the lower limit vehicle speed in the low-speed tracking startable vehicle speed region, the low-speed tracking control function is in a startable state. At this time, the driver performs a starting operation using the low-speed tracking control switch 7. Then, the low-speed tracking control switch 7 transmits a low-speed switch signal indicating activation to the ECU 13, and the ECU 13 activates the low-speed tracking control function.

  The ECU 13 determines whether or not the control by the low-speed tracking control function is being performed (S1). If it is determined in S1 that control is not being performed, the ECU 13 does not perform low-speed tracking control. If it is determined in S1 that the control is being performed, the ECU 13 determines whether or not a preceding vehicle exists (S2). When it is determined in S2 that no preceding vehicle exists, the ECU 13 automatically ends the low-speed tracking control function (S10). Then, the ECU 13 generates image data indicating that the automatic termination is performed, transmits the image signal to the display 12, and transmits the buzzer signal of the ON signal to the buzzer 11. The display 12 displays that the low-speed tracking control function has been automatically terminated. The buzzer 11 outputs a buzzer sound. As a result, the driver knows that the low-speed tracking control function has ended.

  If it is determined in S2 that a preceding vehicle is present, the ECU 13 determines whether or not the host vehicle speed is equal to or higher than the upper limit vehicle speed in the low-speed tracking control vehicle speed region (S3). When it is determined in S3 that the vehicle speed is lower than the upper limit vehicle speed, the ECU 13 controls the brake actuator 9 or the throttle actuator 10 so as to follow the preceding vehicle with a low-speed inter-vehicle distance, and performs low-speed follow-up control (S4). When the preceding vehicle is maintaining or accelerating, the ECU 13 transmits to the throttle actuator 10 a target throttle opening signal set so as to maintain the distance between the preceding vehicle and the low-speed vehicle. The throttle actuator 10 adjusts the throttle valve opening in accordance with the target throttle opening signal. As a result, the vehicle travels following the preceding vehicle with a low-speed inter-vehicle distance. When the preceding vehicle is decelerating, the ECU 13 transmits to the brake actuator 9 a target hydraulic pressure signal set so as to maintain the distance between the preceding vehicle and the low-speed vehicle. The brake actuator 9 adjusts the hydraulic pressure of the wheel cylinder according to the target hydraulic pressure signal. As a result, the vehicle travels following the preceding vehicle with a low-speed inter-vehicle distance.

  When it is determined in S3 that the vehicle speed is equal to or higher than the upper limit vehicle speed, the ECU 13 transmits an information request signal to the navigation device NE. Then, the ECU 13 receives the response signal from the navigation device NE, and acquires the type information of the road on which the vehicle is currently traveling and the traffic jam information near the current position. The ECU 13 determines whether the currently traveling road is an expressway (S5). If it is determined in S5 that the road is a highway, the ECU 13 determines whether or not the current position is in the vicinity of the congestion elimination position (S6). If it is determined in S6 that the position is near the congestion elimination position, the ECU 13 calculates a predicted vehicle speed after a predetermined time of the preceding vehicle from the vehicle speed and acceleration of the preceding vehicle (S7). Then, the ECU 13 determines whether or not the predicted vehicle speed of the preceding vehicle is higher than the vehicle speed threshold (S8). When it is determined in S8 that the vehicle speed is higher than the vehicle speed threshold, the automatic switching condition is satisfied and the congestion is eliminated. It can be estimated that high-speed tracking is possible.

  Therefore, the ECU 13 automatically activates the high-speed tracking control function (S9), and further automatically ends the low-speed tracking control function (S10). The ECU 13 generates image data indicating that automatic switching from the high-speed tracking control function to the low-speed tracking control function is generated, transmits the image signal to the display 12, and transmits the buzzer signal of the ON signal to the buzzer 11. . The display 12 displays that automatic switching has been performed. The buzzer 11 outputs a buzzer sound. Thus, the driver knows that the high-speed tracking control function has been switched to the low-speed tracking control function. The ECU 13 performs high-speed tracking control by controlling the brake actuator 9 or the throttle actuator 10 so as to follow the preceding vehicle with a high-speed inter-vehicle distance. The follow-up control for the preceding vehicle is the same control as the follow-up control with the low-speed follow-up control function. Accordingly, the driver continues the follow-up control similar to the control by the low-speed follow-up control function without performing troublesome operations at the time of switching such as the determination of the cancellation of the traffic jam, the vehicle speed confirmation, and the starting operation.

  If it is determined that the road is not a highway in S5, if it is determined that it is not near the traffic jam resolution position in S6, or if it is determined that the vehicle speed is equal to or lower than the vehicle speed threshold in S8, the automatic switching condition is not satisfied. The device cannot determine whether the traffic jam has been resolved. At this time, the ECU 13 determines whether or not the inter-vehicle distance with the preceding vehicle exceeds a distance threshold (S11). When the congestion is resolved and the preceding vehicle accelerates, the inter-vehicle distance between the preceding vehicle and the host vehicle increases. When it is determined in S11 that the inter-vehicle distance has exceeded the distance threshold, the ECU 13 automatically ends the control by the low-speed tracking control function (S10). In the same manner as described above, the driver is informed that the automatic end has been completed. Incidentally, when the inter-vehicle distance exceeds the distance threshold value, it can be assumed that the vehicle is far away from the preceding vehicle and the traffic congestion has been eliminated, so the low-speed tracking control function is terminated.

  When it is determined in S11 that the inter-vehicle distance is equal to or less than the distance threshold, the ECU 13 controls the brake actuator 9 or the throttle actuator 10 so as to maintain the upper limit vehicle speed in the low-speed tracking control vehicle speed region, and performs vehicle speed maintenance control (S12). Normally, the ECU 13 transmits a target throttle opening signal set so as to maintain the upper limit vehicle speed in the low-speed tracking control vehicle speed region to the throttle actuator 10. The throttle actuator 10 adjusts the throttle valve opening in accordance with the target throttle opening signal. As a result, the host vehicle speed is maintained at the upper limit vehicle speed in the low-speed tracking control vehicle speed region. When the host vehicle speed exceeds the upper limit vehicle speed on a downhill or the like, the ECU 13 transmits a target hydraulic pressure signal set to maintain the upper limit vehicle speed to the brake actuator 9. The brake actuator 9 adjusts the hydraulic pressure of the wheel cylinder according to the target hydraulic pressure signal. As a result, the host vehicle speed is maintained at the upper limit vehicle speed. By this control, the host vehicle keeps traveling while maintaining the upper limit vehicle speed in the low-speed tracking control vehicle speed region. If the inter-vehicle distance is less than or equal to the distance threshold, it is estimated that the traffic jam still continues, so the low-speed tracking control function is continued. When the preceding vehicle exceeds the upper limit vehicle speed in the low speed tracking control vehicle speed region, the host vehicle speed is maintained at the upper limit vehicle speed, and when the preceding vehicle decelerates, the low speed tracking control can be performed.

  Note that if the vehicle speed is within the vehicle speed range in which high-speed follow-up activation is possible but the second to fourth conditions of the automatic switching condition are not satisfied, the ECU 13 can determine whether or not the traffic jam has been resolved. It is up to the driver to decide whether or not to activate. Even when the traffic jam is temporarily resolved and the preceding vehicle accelerates, the traffic jam may continue immediately after that. Even in such a case, the driver can see the situation and make a judgment.

  According to the vehicle speed control device 1, since the automatic switching from the low-speed tracking control function to the high-speed tracking control function is enabled, the burden on the driver is reduced and the usability for the tracking control is improved. In particular, since the vehicle speed control device 1 makes a comprehensive determination from the type of road on which the vehicle is currently traveling, congestion information, and the future traveling state of the preceding vehicle, it is possible to determine with high accuracy whether or not the congestion has been resolved. Can do.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in the present embodiment, it is configured by a vehicle speed control device that has a low-speed tracking control function and a high-speed tracking control function and is controlled by one ECU, but the configurations of the low-speed tracking control function and the high-speed tracking control function are appropriately configured. For example, the low-speed tracking control device and the high-speed tracking control device may be configured by separate ECUs, and the brake control and throttle control (engine control) may be performed by separate ECUs. Also good.

  Further, in the present embodiment, the low-speed tracking control function and the high-speed tracking control function are configured to perform vehicle speed maintenance control in addition to tracking control, but only tracking control may be performed.

  In the present embodiment, the low-speed tracking control switch and the high-speed tracking control switch are provided. However, the operation system for the low-speed tracking control function and the high-speed tracking control function may be appropriately configured. You may comprise with the mode changeover switch which switches an ON / OFF switch, a low-speed tracking control function, and a high-speed tracking control function.

  In this embodiment, the laser sensor is applied as means for detecting the distance from the preceding vehicle. However, other detection means such as a millimeter wave sensor and a stereo camera may be used.

  In this embodiment, the yaw rate sensor is applied as means for detecting the turning state of the vehicle. However, other detection means such as a steering angle sensor may be used.

  In this embodiment, the display and buzzer are applied as means for notifying the driver, but other means such as voice output may be used.

  In the present embodiment, an acceleration prohibition vehicle speed region is provided, and the low-speed tracking control function is terminated when the vehicle speed exceeds the upper limit vehicle speed of the acceleration prohibition vehicle speed region by the driver's accelerator operation. The low-speed tracking control function may be terminated when the upper limit vehicle speed in the low-speed tracking control vehicle speed region is exceeded by the driver's accelerator operation.

  In the present embodiment, the low-speed tracking control function automatically changes from the low-speed tracking control function to the high-speed tracking control function when the host vehicle speed is equal to or higher than the upper limit vehicle speed in the low-speed tracking control vehicle speed range, the highway is near the congestion elimination position, and the preceding vehicle predicted vehicle speed is higher than the vehicle speed threshold. However, when the vehicle speed becomes equal to or higher than the upper limit vehicle speed in the low-speed tracking control vehicle speed area, at least one of the three conditions: the highway, the vicinity of the congestion elimination position, and the predicted vehicle speed of the preceding vehicle is higher than the vehicle speed threshold. When one condition is satisfied, the low-speed tracking control function may be automatically switched to the high-speed tracking control function.

  In the present embodiment, as one of the automatic switching conditions from the low-speed tracking control function to the high-speed tracking control function, the host vehicle speed is set to be equal to or higher than the upper limit vehicle speed of the low-speed tracking control vehicle speed range. It may be higher than the lower limit vehicle speed.

  In the present embodiment, a highway is used as one of the automatic switching conditions from the low-speed tracking control function to the high-speed tracking control function. However, an automobile exclusive road other than the highway may be used.

  Further, in this embodiment, the vehicle speed is predicted as the traveling state of the preceding vehicle, and the predicted vehicle speed is used as one of the automatic switching conditions, but the traveling state of other preceding vehicles such as the acceleration of the preceding vehicle is predicted. It may be used.

  In this embodiment, the configuration is such that traffic jam information and travel road information are acquired from the navigation device. However, when the navigation device is not installed, a device that can acquire information from VICS is installed, and the traffic jam is transmitted from the device. It is good also as a structure which acquires information.

  In this embodiment, the information request signal is transmitted to the navigation device and the response signal is received to acquire the traffic jam information and the traveling road information. However, the traffic jam from the navigation device at regular intervals. Information and traveling road information may be provided.

It is a block diagram of the vehicle speed control apparatus which concerns on this Embodiment. It is a figure which shows the relationship between the control vehicle speed area | region and the startable vehicle speed area | region in the low speed tracking control function of the vehicle speed control apparatus of FIG. It is a flowchart which shows the operation | movement at the time of automatic switching from the low-speed tracking control function to the high-speed tracking control function in the vehicle speed control apparatus of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle speed control apparatus, 2 ... Laser sensor, 3 ... Yaw rate sensor, 4 ... Vehicle speed sensor, 5 ... Brake switch, 6 ... Accelerator opening sensor, 7 ... Low speed tracking control switch, 8 ... High speed tracking control switch, 9 ... Brake actuator, 10 ... Throttle actuator, 11 ... Buzzer, 12 ... Display, 13 ... ECU

Claims (3)

A vehicle travel control device that controls a travel state of a vehicle to follow a preceding vehicle,
Low-speed tracking control means;
High-speed follow-up control means including a vehicle speed region in which a control start permission vehicle speed region overlaps a control vehicle speed region of the low-speed follow-up control unit;
Control execution determination means for determining whether or not the control by the low-speed tracking control means is being executed;
Vehicle speed detection means for detecting the vehicle speed;
Vehicle speed determination means for determining whether or not the vehicle speed detected by the vehicle speed detection means is within a control start permission vehicle speed region of the high-speed follow-up control means;
Predicting means for predicting the traveling state of the preceding vehicle,
When the control by the low-speed tracking control means is being executed and the vehicle speed is within the control start permission vehicle speed range of the high-speed tracking control means, the traveling state of the preceding vehicle is controlled by the high-speed tracking control means. When it is predicted that the vehicle travels at a vehicle speed, the vehicle travel control device switches from the control by the low-speed follow-up control means to the control by the high-speed follow-up control means. A vehicle travel control device that controls a travel state of a vehicle to follow a preceding vehicle,
Low-speed tracking control means;
High-speed follow-up control means including a vehicle speed region in which a control start permission vehicle speed region overlaps a control vehicle speed region of the low-speed follow-up control unit;
Control execution determination means for determining whether or not the control by the low-speed tracking control means is being executed;
Vehicle speed detection means for detecting the vehicle speed;
Vehicle speed determination means for determining whether or not the vehicle speed detected by the vehicle speed detection means is within a control start permission vehicle speed region of the high-speed follow-up control means;
Obtaining means for obtaining vehicle driving environment information,
Vehicle speed when the running environment of the vehicle is controlled by the high-speed tracking control means when the control by the low-speed tracking control means is being executed and the vehicle speed is within the control start permission vehicle speed range of the high-speed tracking control means When the vehicle is capable of traveling in a vehicle environment, the vehicle travel control device switches from the control by the low-speed tracking control means to the control by the high-speed tracking control means. The acquisition means acquires information as to whether or not the vehicle is traveling on an automobile road,
3. The vehicle travel control device according to claim 2, wherein when the vehicle is traveling on an automobile exclusive road, the control is switched from the control by the low-speed tracking control unit to the control by the high-speed tracking control unit.

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