JP2000033826A - Control device for automatic transmission of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve drivability by computing running resistance and driving force based on detected running condition, estimating slope of the road, comparing the slope with a predetermined value to evaluate the driving state, computing the maximum driving force of the current gear ratio, and setting a gear ratio such that driving force difference is a predetermined value. SOLUTION: In this control device of automatic transmission for vehicle, operation condition of the internal combustion engine is detected with a water temperature sensor 106, a throttle position sensor 108, an accelerator position sensor 110, a braking switch 112, a vehicle speed sensor 122, a steering angle sensor 128 and the like. Then, an integrated control part 300 computes running resistance and driving force. Based on the running resistance and driving force, slope of the road is estimated, which is compared with a predetermined value to evaluate the driving state. Next, the maximum driving state that the engine can output at the current gear ratio is computed, computing difference in driving force from this maximum driving force, setting the driving force such that the difference computed according to the evaluation result is a predetermined value (target instantaneous surplus driving force). Accordingly, a gear ratio of the automatic transmission is determined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device such as an automatic transmission for a vehicle, and more specifically, to a gear ratio (or driving force) that reflects the driver's intention to the operation of the vehicle as much as possible. The present invention relates to a control device such as an automatic transmission for a vehicle that controls the speed of a vehicle.

[0002]

2. Description of the Related Art As a control device or a driving force control device for a vehicle automatic transmission, for example, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Unexamined Patent Publication, a method using two types of driving force control methods has been proposed.

In this prior art, on an uphill, a target driving force with respect to a throttle opening is divided equally between a maximum driving force and a minimum driving force so as to improve a feeling of acceleration.
On a downhill, the target acceleration is controlled in consideration of an integrated value of the target acceleration and a past deviation so that the acceleration is constant.

That is, the output torque of the engine is calculated using the engine speed, the throttle opening, the amount of intake air, or the like, or the output torque is calculated from the input / output arithmetic expression of the torque converter, and the torque value and the vehicle speed are calculated. Is calculated from the differential signal of the vehicle and the flat ground running resistance torque.

[0005]

However, in the above-mentioned prior art, a driving situation or environment such as a gradient is not taken into account, and a change in driving force due to a change in running resistance when there is a gradient is not reflected. However, the driving force could not be changed depending on the driving conditions.

[0006] Further, although it is intended to improve the feeling of acceleration on an uphill, it does not output a specific driving force. That is, since the target acceleration is controlled so as to be constant while correcting the deviation from the target driving force during the past traveling, the past correction value is applied even when there is a gradient change during a downhill, The driving force was not always constant when the gradient changed.

Furthermore, even if the acceleration is controlled to be constant, the control is to cancel the deviation due to the difference in vehicle weight and the like. And the control was not stable.

Therefore, an object of the present invention is to solve the above-mentioned disadvantages, and paying attention to the fact that the superiority of drivability is remarkable when going up and down hills, and estimating the gradient to estimate the running situation such as uphill or downhill. It is an object of the present invention to provide a control device such as an automatic transmission for a vehicle which makes a determination and controls a gear ratio so as to obtain a desired driving force to improve drivability.

Further, a second object of the present invention is to improve the drivability by calculating an evaluation index indicating the tendency of drivability and controlling the speed ratio of the vehicle in accordance with the calculated evaluation index. It is to provide a control device.

[0010]

In order to solve the above-mentioned object, according to the present invention, in a control device for an automatic transmission for a vehicle, an operating state of a vehicle and an internal combustion engine mounted thereon is detected. Operating state detecting means, running resistance calculating means for calculating running resistance of the vehicle based on the detected operating state, and driving force calculation for calculating driving force output by the vehicle based on the detected operating state Means, a gradient estimating means for estimating a gradient of a traveling road on which the vehicle is traveling, based on the calculated traveling resistance and driving force, comparing the estimated gradient with a predetermined value, and determining a traveling state of the vehicle. Determining means for calculating a maximum driving force that the vehicle can output at a current gear ratio to calculate a driving force difference from the driving force, and determining the calculated driving force difference in accordance with the determination result; The value of the Gear ratio setting means for setting the gear ratio to be, and on the basis of the set gear ratio and composed as comprising a gear ratio determining means for determining a gear ratio of the vehicle automatic transmission. As a result, it is possible to realize appropriate gear ratio control according to the gradient of the traveling road and improve drivability.

According to a second aspect of the present invention, the gear ratio setting means corrects the calculated driving force difference according to at least one of the estimated gradient and the detected vehicle speed. did. As a result, it is possible to further realize appropriate gear ratio control in accordance with the gradient of the traveling road and improve drivability.

According to a third aspect of the present invention, the speed ratio setting means corrects the calculated driving force difference based on at least a throttle opening and a throttle opening change amount. As a result, it is possible to improve the drivability by realizing the speed ratio control according to the traveling road gradient and the driver's request.

According to a fourth aspect of the present invention, when the vehicle is determined to be downhill on the basis of the determination result, the speed ratio setting means determines the speed ratio based on the calculated driving force difference and the running resistance. The gear ratio is set. As a result, it is possible to realize the speed ratio control according to the gradient of the traveling road, particularly the descending slope, and to improve the drivability.

According to a fifth aspect, when the speed ratio setting means determines that the vehicle is on a downhill from the determination result, the calculated driving force difference matches the running resistance. The speed ratio is set as described above. Thus, during downhill traveling, it is possible to realize gear ratio control suitable for the driver's intention and improve drivability.

According to a sixth aspect of the present invention, the speed ratio setting means determines that the difference between the calculated driving force difference and the running resistance when the vehicle is determined to be downhill from the determination result. The gear ratio is set so as to be a predetermined value. Thus, during downhill traveling, it is possible to realize gear ratio control suitable for the driver's intention and improve drivability.

According to a seventh aspect of the present invention, operating state detecting means for detecting an operating state of the vehicle and an internal combustion engine mounted on the vehicle, including at least a throttle opening, wherein the vehicle outputs an output based on at least the throttle opening. Actual driving force calculating means for calculating an actual driving force to be performed, and driver request estimated value calculating means for calculating a driver required estimated value based on at least the detected throttle opening (more specifically, at least the detected Calculating a driver request estimated value based on the throttle opening and a throttle opening change amount by inputting the throttle opening to a first model describing a preset driving state of the vehicle. Means), indexing means for indexing the calculated actual driving force and the driver's demand estimation value (more specifically, at least the detected throttle opening Input to a first model describing a preset ideal response characteristic of the vehicle to calculate a required output of the driver, and calculate a driving force of the own vehicle from a driving force difference from the calculated driving force. Own vehicle driving force calculating means for calculating, and a driving state index calculating means for calculating the driving state index by indexing the calculated driver request estimated value and the own vehicle driving force),
Driving characteristic determining means for determining which of the at least first driving characteristic and second driving characteristic different in the driving force responsiveness the driver is requesting based on the index; Accordingly, the vehicle is provided with driving force control means for controlling the driving force of the vehicle via at least one of the output and the gear ratio of the internal combustion engine.

[0017] Thus, it is possible to realize driving force control according to the driver's request while taking into account the traveling state of the own vehicle, thereby achieving both improved drivability and improved fuel efficiency.

[0018] According to the present invention, the driver can control the second vehicle.
When it is determined that the driving characteristic of the vehicle is required, the driving force control unit estimates a gradient of a traveling path on which the vehicle is traveling, and sets a target value of the driving force of the vehicle according to the estimated gradient. And feedback control is performed so as to reach the set target value. As a result, while taking into account the traveling state of the own vehicle, driving force control according to the driver's request can be further realized to achieve both improved drivability and improved fuel efficiency.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram generally showing a control device such as an automatic transmission for a vehicle according to the present invention. In the case of the illustrated embodiment, a belt-type continuously variable transmission (CVT) is provided as the automatic transmission.

In FIG. 1, reference numeral 10 denotes an internal combustion engine or its main body (hereinafter referred to as "engine" or "engine main body").
). The engine 10 includes an intake pipe 12 and a throttle valve 14 arranged on the way. The throttle valve 14 is mechanically disconnected from an accelerator pedal 16 disposed on the floor of a vehicle driver's seat (not shown), is connected to a pulse motor 18, and is driven by its output.

An output shaft (crankshaft) 20 of the engine (body) 10 is connected to a belt-type continuously variable transmission 24 (CVT; hereinafter referred to as "transmission").

More specifically, an output shaft 20 of the engine (body) 10 is connected to an input shaft 28 of the transmission 24 via a dual mass flywheel 26.
Engine (body) 10 and transmission 24
Is mounted on a vehicle indicated by reference numeral 29 only.

The transmission 24 includes a metal V-belt mechanism 3 disposed between an input shaft 28 and a counter shaft 30.
2, a planetary gear type forward / reverse switching mechanism 36 disposed between the input shaft 28 and the drive-side movable pulley 34, and a starting clutch 42 disposed between the counter shaft 30 and the differential mechanism 40. Be composed. The power transmitted to the differential mechanism 40 is transmitted to left and right drive wheels (not shown) via a drive shaft (not shown).

The metal V-belt mechanism 32 includes a drive-side movable pulley 34 provided on the input shaft 28 and a counter shaft 3
The pulley comprises a driven movable pulley 46 disposed above the pulley and a metal V-belt 48 wound between the two pulleys. The drive-side movable pulley 34 includes a fixed pulley half 50 disposed on the input shaft 28, and a movable pulley half 52 movable relative to the fixed pulley half 50 in the axial direction.

On the side of the movable pulley half 52, a drive cylinder chamber 54 is formed surrounded by a cylinder wall 50a connected to the fixed pulley half, and an oil passage 54a is formed in the drive cylinder chamber 54. A side pressure for moving the movable pulley half 52 in the axial direction is generated by the hydraulic pressure supplied through the pulley.

The driven-side movable pulley 46 is composed of a fixed pulley half 56 disposed on the counter shaft 30 and a movable pulley half 58 that can move axially relative to the fixed pulley half 56. On the side of the movable pulley half 58, a driven cylinder chamber 60 is formed surrounded by a cylinder wall 56a connected to the fixed pulley half 56, and is supplied into the driven cylinder chamber 60 via an oil passage 60a. The hydraulic pressure generates a side pressure that moves the movable pulley half 58 in the axial direction.

A regulator valve group 64 for determining a pulley control oil pressure supplied to the drive-side cylinder chamber 54 and the driven-side cylinder chamber 60;
Shift control valve group 6 for supplying pulley control oil pressure to 60
6 are set, an appropriate pulley side pressure is set so that the V-belt 48 does not slip, the pulley width of both pulleys 34 and 46 is changed, and the winding radius of the V-belt 48 is changed. Thus, the gear ratio is changed steplessly.

The planetary gear type forward / reverse switching mechanism 36 includes a sun gear 68 connected to the input shaft, a carrier 70 connected to the fixed pulley half 50, a ring gear 74 which can be fixed and held by a reverse brake 72, and a sun gear. And a forward clutch 76 capable of connecting the carrier 68 and the carrier 70.

When the forward clutch 76 is engaged, all gears rotate integrally with the input shaft 28, and the drive pulley 34
Are driven in the same direction as the input shaft 28 (forward direction). When the reverse brake 72 is engaged, the ring gear 74 is fixed and held, so that the carrier 70 is driven in the direction opposite to the sun gear 68, and the drive pulley 34 is driven in the direction opposite to the input shaft 28 (reverse direction). Is done. When both the forward clutch 76 and the reverse brake 72 are released, the power transmission via the forward / reverse switching mechanism 36 is cut off, and the power transmission between the engine 10 and the drive-side drive pulley 34 is performed. I will not be.

The starting clutch 42 is a clutch for controlling the power transmission between the counter shaft 30 and the differential mechanism 40 to be on (engaged) and off (released). The output of the engine is divided and transmitted to left and right wheels (not shown) by a differential mechanism 40 via gears 78, 80, 82, and 84. When the starting clutch 42 is off (disengaged), the transmission is in a neutral state.

The operation of the start clutch 42 is controlled by a clutch control valve 88, and the reverse brake 72 and the forward clutch 76
Is controlled by a manual shift valve 90 in response to operation of a manual shift lever (not shown).

The control of these valve groups is performed based on control signals from a transmission control unit 100 composed of a microcomputer.

The crank angle sensor 102 is located at an appropriate position near the camshaft (not shown) of the engine body 10.
And outputs a signal proportional to the crank angle (the engine speed Ne is calculated by counting the crank angle). Further, an absolute pressure sensor 104 is provided at an appropriate position downstream of the throttle valve 14 in the intake pipe 12, and outputs a signal P proportional to the absolute pressure (engine load) PBA in the intake pipe.

A water temperature sensor 106 is provided at an appropriate position on a cylinder block (not shown), and outputs a signal proportional to the engine cooling water temperature TW. Further, an intake air temperature sensor 107 is provided at an appropriate position of the intake pipe 12, and outputs a signal proportional to the intake air temperature (corresponding to substantially the outside air temperature).

A throttle opening sensor 108 is provided near the throttle valve 14 to output a signal proportional to the throttle opening θth, and an accelerator opening sensor 110 is provided near the accelerator pedal 16. A signal proportional to the accelerator opening ACC depressed by the driver is output.

A brake switch 112 is provided near a brake pedal or a brake mechanism (not shown), and outputs a brake ON signal in response to a driver's brake operation.

In the transmission 24, a rotation speed sensor 114 is provided near the input shaft 28, and outputs a signal proportional to the rotation speed NDR of the input shaft 28.
In the vicinity of the driven-side movable pulley 46, a rotation speed sensor 11 is provided.
6 is provided, and outputs a signal proportional to the rotation speed of the driven-side movable pulley 46, that is, the rotation speed NDN of the input shaft (counter shaft 30) of the starting clutch 42. Also, the gear 78
, A rotation speed sensor 118 is provided, and the rotation speed of the gear 78, that is, the rotation speed NO of the output shaft of the starting clutch 42
Outputs a signal proportional to UT.

Further, a vehicle speed sensor 1 is provided near a drive shaft (not shown) connected to the differential mechanism 40.
22 for outputting a signal proportional to the vehicle speed V. A shift lever position switch 124 is provided near a shift lever (not shown) on the floor of the driver's seat, and a range position (D, N, P,...) Selected by the driver is provided.
Output a signal proportional to

An acceleration sensor 126 is provided near the center of the vehicle 29, and outputs a signal proportional to the lateral acceleration G acting in a direction orthogonal to the traveling direction of the vehicle 29. A steering angle sensor 12 is provided near a steering wheel (not shown) disposed in a vehicle driver's seat (not shown).
8 for outputting a signal according to the steering angle.

As described above, this device includes the transmission control unit 100, and also includes the engine control unit 200 similarly formed of a microcomputer. The outputs of the crank angle sensor 102, the absolute pressure sensor 104, the water temperature sensor 106, and the throttle opening sensor 108 in the above-described sensor group are input to the control units 100 and 200.

This device also has an integrated control unit 300 similarly composed of a microcomputer, and includes an accelerator opening sensor 110, a vehicle speed sensor 1
Outputs such as 22 are input to the integrated control unit 300.

The integrated control unit 300 determines a target gear ratio, that is, a target value of the input rotational speed NDR, and sends it to the transmission control unit 100.

The transmission control unit 100 drives the movable pulleys 34 and 46 so as to reach the target NDR,
Control the gear ratio. Here, the target NDR is the target rotation speed of the drive-side movable pulley 34 of the transmission 24. By defining the target NDR with respect to the vehicle speed V, the gear ratio (hereinafter referred to as “ratio” or “ratio”) is univocally determined. Determined and controlled.

As described above, in this embodiment, since the transmission 24 is provided and the ratio can be controlled steplessly, the drivability can be controlled by optimally controlling the ratio according to the driving state, as described later. Can be improved.

Further, the integrated controller 300 determines the target throttle opening and sends it to the throttle controller 400. The throttle control unit 400 drives the throttle valve 14 via the pulse motor 18 so as to have the determined value.

Next, the operation of the control device for an automatic transmission for a vehicle according to the present invention will be described.

FIG. 2 is a flow chart showing the operation. Before starting the description of the figure, the operation of a control device such as an automatic transmission for a vehicle according to the present invention will be outlined with reference to FIG.

As described above, this apparatus focuses on the fact that the superiority of drivability appears remarkably when going up and down a hill, and based on the analysis of the driving results mainly on mountainous roads, the factors affecting the drivability are determined by physical quantities (driving force). ), And the relationship between drivability and physical quantities found there was obtained as an evaluation index, and the ratio (or driving force) was controlled based on that.

Specifically, a physical quantity state estimation model as shown in FIG. 3 was created, and the correlation with the drivability was analyzed. More specifically, in the manipulated variable input unit, the degree of driver demand is estimated based on the accelerator opening operated by the driver and is indexed. FIG. 4 shows the model.

One of the characteristics of the model shown in FIG. 4 is that the accelerator opening and the amount of depression of the brake are grasped in the same dimension, and the return of the accelerator is modeled as a brake operation. That is, as shown in FIG. 5, the driving force (torque) was captured as a negative value based on the estimated brake (described later). Also, as shown in FIG. 6, the gain is adjusted based on the time for stepping on the accelerator pedal and the brake pedal.
These will be described later.

In the own vehicle section of the model shown in FIG. 3, the own vehicle gain is estimated. That is, as shown in FIG. 7, a model showing the difference between the ideal vehicle response and the actual vehicle response is created, and based on the model, the actual output and the driver request output are combined, and more specifically, the difference is calculated. Then, the responsiveness (driving force) of the own vehicle is estimated. This will also be described later.

Next, the index obtained from the model shown in FIG. 4 and the index obtained from the model shown in FIG. 7 are averaged and compared with a predetermined value to determine whether the driver intends the sport running characteristic or the relaxed running characteristic. Determine if Here, the sports driving characteristics are characteristics of a high response when the driving force change with respect to the accelerator opening is high, and the relaxing driving characteristics are low response characteristics when the driving force change with the accelerator opening is compared with the sports driving characteristic, in other words. It means the characteristic that the degree of driver intervention can be reduced. The sports running characteristics correspond to the first running characteristics described above, and the relaxed running characteristics correspond to the second running characteristics described above.

When it is determined that the driver intends to have the relaxed driving characteristic, the driving condition is determined based on the gradient estimated from the vehicle speed and the like, that is, whether the vehicle is traveling uphill, downhill or on flat ground. Judgment, the ratio is controlled so that the driving force becomes a desired value, and when it is determined that the driver intends the sport running characteristics, the driving force also becomes the desired value, and the relaxed driving is performed. The ratio is controlled so that the driving force response is higher than the characteristic.

Specifically, a ratio control output index is calculated to obtain a ratio ratio (ratio multiplied value), and the ratio is determined by multiplying the base ratio map value.

The above will be described with reference to the flow chart of FIG. The illustrated program is, more specifically, an operation performed in the integrated control unit 300, and is executed at predetermined time intervals, for example, at 0.1 second intervals.

First, in S10, the gradient θ,
That is, the gradient θ of the traveling road on which the own vehicle is traveling is estimated (calculated). FIG. 8 is a subroutine flowchart of the process in S10.

In this control, as described above, the gradient of the traveling road is calculated (estimated) in order to judge the traveling condition. The estimated value obtained is referred to as “span gradient estimation”, and the estimated value obtained is referred to as “long span estimation gradient”. The estimated value obtained is referred to as “short span estimation gradient”).

More specifically, the gradient estimation is performed by using two types of predetermined detection conditions, techniques, detection timings, and filtering in the gradient value estimation, in other words, changing the time constant of the filter. did. Then, according to the driving state of the vehicle, one of the estimated gradients is selected to determine the traveling environment, and the ratio control is performed.

Referring to FIG. 8, from S100 to S110
The processing of (a) shows the above-described short span estimation gradient calculation processing. In S100, the detected vehicle speed V and acceleration d
v (vehicle acceleration; first-order difference value or differential value of detected vehicle speed), throttle opening degree θth, ratio (NDR) rat
io and the steering angle (lateral acceleration G) are read.

FIG. 9 is an explanatory diagram showing the processing of S100, which is performed using a low-pass filter 500 as shown. That is, when reading the detected value, the low-pass filter 50 is used.
Filter processing is performed via 0.

More specifically, when estimating the short-span gradient, the cutoff frequency of the low-pass filter 500 is set high, and the response is increased by setting the attenuation characteristic low. On the other hand, when estimating the long-span gradient, the cutoff frequency is set low and the damping characteristic is set high.In other words, high accuracy is achieved by removing high frequency components that have many disturbance components due to the effects of acceleration and deceleration. I tried to raise it.

In S100, since the short span gradient is estimated, the filter output value in which the cutoff frequency is set high and the attenuation characteristic is set low is read.

Then, the program proceeds to S102, in which a torque Te output from the engine (main body) 10 is calculated (estimated) using a throttle opening-torque conversion table (not shown) appropriately set from the detected throttle opening θth. I do.

Then, the program proceeds to S104, in which the driving force F output from the vehicle 29 is calculated (estimated). Specifically, it is calculated using the following equation. F = (1 / r) × [(Te−Tf) × ratio × k−dNe / dt · C] [kgf]. . . Equation 1 Here, r: tire radius, Tf: total value of transmission friction torque, k: final reduction ratio, and C: inertial mass component.

Next, the routine proceeds to S106, where the corner resistance Rc
Is calculated. Here, the corner resistance means a deceleration force generated by deformation of the tire at the time of cornering (that is, turning force). FIG. 10 is a block diagram illustrating the process.

In the following description, a lateral G map characteristic (characteristic not shown) is searched from the value obtained by converting the steering steering angle input value into an absolute value and the detected vehicle speed, and the lateral acceleration G (acceleration acting on the vehicle in the lateral direction) is obtained. Ask for. Next, map characteristics (characteristics not shown) that are appropriately set from the calculated lateral G and the detected vehicle speed
To find the corner resistance Rc.

The calculated (estimated) accuracy of the running resistance R can be increased by adding the obtained corner resistance Rc at the time of calculating the running resistance R described later. Note that the corner resistance hold value is obtained and used in mountain / city area determination described later.

Returning to the description of FIG. 8, the program proceeds to S108, where the running resistance R is calculated (estimated). Specifically, using the corner resistance Rc and the detection parameter values (vehicle speed V, acceleration dv) obtained as described above and values (vehicle weight, air resistance coefficient, rolling resistance coefficient) previously obtained and stored, and the like, Is calculated as follows.

R = ρCdAV ² + ma + msinθ + μmcosθ + Rc [kgf]. . . Equation 2 where ρ: air density coefficient, Cd: air resistance coefficient, A:
Projection area of the entire vehicle, θ: slope, μ: rolling resistance coefficient,
m: vehicle weight, a: acceleration, Rc: corner resistance.

Next, the routine proceeds to S110, where
Is calculated from the following equation. sin θ = [F− {ρCdAV ² −ma + μm cos θ + Rc}] / m [°]. . . The value obtained by Expression 3 is defined as the short span estimation gradient θ short. In addition, 0.1 sec for the on-board microcomputer
Since it is difficult to solve during the control cycle of c and there is no need to solve it, sin θ is actually treated as it is as the gradient θ. Incidentally, as far as the inventors have confirmed, the estimated short span gradient value thus obtained has an accuracy of ± 5 ° or less.

Then, the program proceeds to S112, in which it is determined whether or not the ON signal of the brake switch 112 has been output. That is, it is determined whether or not the driver is operating a brake mechanism (not shown).

When the result in S112 is affirmative, the program proceeds to S114, in which it is determined whether the brake operation was performed during the previous control cycle (previous program loop). The previous value of ol
d Hold the θ short as the pre-brake gradient value θbeforebrk.

On the other hand, if the result in S114 is affirmative, S11
8, the product of the estimated short-span gradient value and the vehicle weight m is set as the gradient-equivalent resistance Rb at the time of braking (during the braking operation), and the process proceeds to S120 to calculate (estimate) the braking force Fbrk from the equation in the figure. I do.

That is, assuming that the road surface gradient is constant before and after the brake switch 112 is turned on, the braking force is calculated as a deviation between the driving force corresponding to the gradient immediately before the brake switch 112 is turned on and the driving force corresponding to the gradient during braking. You can ask.

In the process of S120, the pre-brake gradient estimated value θbeforebrk is held since it was previously determined that the brake was also depressed, and the pre-brake gradient equivalent resistance msin θbeforebrk is obtained from the value.
Resistance msi equivalent to the gradient at the time of braking determined in S118
The braking force Fbrk is calculated from the difference from the nθ short circuit.

Then, the program proceeds to S122, in which (S
116) The previous value ol of the value θ short and the estimated gradient value
It is determined whether the difference Δθ short from dθ is equal to or less than a predetermined value α. That is, when the vehicle spins or slips, the estimated gradient θ short becomes an abnormally high value on the negative side, so the threshold α is appropriately set, and in S122, the short span estimated gradient value θ short and the previous value of the estimated gradient value are compared. When it is determined that the difference Δθ short from the value old θ is equal to or greater than the threshold value α, it is determined that spin or slip has occurred.

When the result in S122 is affirmative, it can be determined that the vehicle is traveling on a normal road, and the process proceeds to S124, where the pre-brake gradient estimated value θbeforebrk is set as the gradient estimated value θ.

On the other hand, when the result in S122 is NO, it is considered that the vehicle is traveling on a rough road with a small gripping force and a slip state has occurred, so the flow proceeds to S126 to perform a low μ road control process. This will be described later.

Next, the process proceeds to S124, in which the held pre-brake estimated gradient value θbeforebrk is set to the estimated gradient value θ, and the process proceeds to S128 to set the dv value 20 times before to 20old dv.
Proceeding to S130, the estimated gradient value θ is set to old θ, and the program ends.

On the other hand, when the result in S112 is NO, that is,
When it is determined that the brake is not currently operated, the process proceeds to S132, and it is determined whether a time of 0.5 sec or more has elapsed since the brake switch was turned off.

When the result in S132 is affirmative, the program proceeds to S134, where it is determined whether or not the difference between the current acceleration dv and the acceleration 20old dv ^two seconds before is 1.0 [m / sec ² ] or less, as shown in the figure.

When the result in S134 is affirmative, it can be determined that the vehicle is in a steady running state with a small change in speed.
Calculate the long. That is, the long span estimation gradient is calculated only when the vehicle is traveling stably with a change in acceleration smaller than a predetermined value.

Steps S136 to S146 show the long-span estimation gradient calculation process. In step S136, the detected vehicle speed V, acceleration dv, throttle opening θth, ratio rat
io and the steering angle (lateral acceleration G) are read.

Here, as described with reference to FIG. 9, the cut-off frequency of the filter 500 is set low and the attenuation characteristic is set high to read the filtered sensor output value. Note that the processing from S138 to S144 is the same as the calculation processing of the estimated short span gradient, and thus the description is omitted. The estimated gradient value obtained in S146 is set to θ long. This value has an accuracy of ± 2 ° or less as far as the inventors have confirmed.

Note that the short span estimation gradient and the long span estimation gradient are selectively used as described later depending on the application.

Subsequently, the flow proceeds to S148, in which the vehicle weight is calculated (estimated) by an appropriate method. The vehicle weight is obtained and stored in advance, but is corrected when it is determined that the vehicle is running stably to increase the accuracy.

Then, the process proceeds to S150, where the long span estimated gradient value θ long obtained in S146 is used as the estimated gradient value θ,
Proceed to S128 and below.

When the result in S132 is negative, that is, when it is determined that the predetermined period 0.5 seconds has not elapsed since the brake switch was turned off, or when the result in S134 is negative, the process proceeds to S152, where the long span estimation gradient is set. The previous value old θ long of the value is set as the long span estimation gradient value θ long.

Then, the process proceeds to S154, in which it is determined whether or not the difference Δθ short between the estimated short span value θ short calculated in S110 and the previous value old θ of the estimated gradient value is equal to or smaller than a predetermined value β. That is, similarly to the processing of S122, the threshold value β is set, and it is determined that the difference Δθ short between the short span estimated gradient value θ short and the previous value old θ of the estimated gradient value is equal to or larger than the threshold value β. At this time, it is determined that spin or slip has occurred.

When the result in S154 is affirmative, it is determined that the vehicle is traveling normally, and the routine proceeds to S156, where the pre-brake gradient estimated value θ short is set as the gradient estimated value θ. On the other hand, S1
If the result in 54 is negative, it is considered that the vehicle is traveling on a rough road, so the flow proceeds to S126 to perform a low μ road control process.

Returning to the flow chart of FIG.
Proceeding to 11, the mountain and city area judgment is performed. This will be described later.

Next, the program proceeds to S12, in which the braking force fbrk is
Is estimated.

When the driving force F immediately before braking and the driving force F during braking are calculated, they are as follows. Incidentally, various values such as the driving force F immediately before the braking are added with 0, and those during the braking are added with 1.

The driving force immediately before the braking is calculated from the following equation. ^{F0 = ρCdAV0 2 + ma0 + msinθ0} + μmc
osθ0 + fbrk0 + Rc0 [kgf]

The driving force during braking is calculated from the following equation. F1 = ρCdAV1 ² + ma1 + msinθ1 + μmc
osθ1 + fbrk (1) + Rc1 [kgf]

From the assumption, the following is derived. msinθ0 = msinθ1 Rc0 = Rc1 = 0 μmcosθ0 = μmcosθ1

Accordingly, the braking force fbrk is obtained as follows. fbrk = fbrk1-fbrk0 = F1- F0-ρCdAV1 2 -ρCdAV0 2 - m (a1-a0) -Rc1-Rc0. . . Equation 3

Next, the program proceeds to S14, in which the above-described driver request estimation is performed. The driver's request is indicated by a throttle opening and a throttle opening change amount.

Referring to FIG. 4, the reverse torque map is retrieved from the estimated braking force fbrk, converted into a negative throttle opening, and subtracted from the detected throttle opening. That is, as shown in FIG. 5, the estimated braking force is converted into a driving force around the axle, and a map having a characteristic opposite to that of the map previously used for calculating the torque Te is searched to calculate a throttle opening value. Negative value.

That is, in this control, as shown in the upper part of FIG. 4, the accelerator opening and the amount of depression of the brake are grasped in the same dimension, and the movement in the returning direction beyond the full throttle of the accelerator is regarded as a brake operation and modeled. .

Next, the obtained difference is multiplied by a P (proportional) gain, and the obtained value is peak-held and attenuated with time, and the obtained value is defined as a driver request (determined by the throttle opening (θth)). Similarly, the obtained difference (not shown) is multiplied by a D (differential) gain, and a value obtained by peak-holding and attenuating the obtained value with time is obtained as a driver request degree (throttle opening degree change amount dth). More specifically, it indicates the amount of change in the throttle opening).

Since the D gain is used because the accelerator stepping speed or the step change time indicates the magnitude of the driver's demand, the differential value of the accelerator opening is weighted as a method on a model that reflects this. That's why. In addition, as shown in FIG. 6, the D gain is changed by obtaining the time for changing over from the throttle to the brake.

At the same time, the aforementioned vehicle driving force (corresponding to the aforementioned vehicle gain) is estimated.

Referring to FIG. 7, the upper part of the figure is a model (first model) describing the ideal response of the own vehicle.
And the lower part shows a model (second model) that describes the actual response of the own vehicle. Then, the driving force is obtained by the same calculation as in FIG. 4 using the model 1, and the product obtained by multiplying the detected vehicle speed is regarded as the driver's required output.

Further, the estimated driving force is calculated based on the engine torque Te using the second model, and the product obtained by multiplying the value obtained by subtracting the estimated braking force by the detected vehicle speed is similarly calculated by the vehicle. Is regarded as the actual output output to Then, the actual output is subtracted from the required output in the addition / subtraction stage to obtain a difference, which is set as a deviation output (or a difference output). This deviation output indicates how much the driver's demand deviates from the actual output.

In the flow chart of FIG.
The process proceeds to step S16, and the obtained value is used as an index from 1 to 5 points. The process proceeds to step S18 to combine, more specifically, average. FIG. 11 is an explanatory diagram showing the processing. Specifically, it is indexed (dimensionless) with a non-dimensional numerical value from 1 to 5 points using an appropriate function (represented by a linear function in the figure), and the calculated value is searched for a corresponding evaluation index.

Thus, the driver's request (whether the vehicle is intended for a relaxed driving or a sports driving) is displayed in the index based on the engine performance of the own vehicle.
It is possible to create an evaluation index reflecting the above. Although the average is used as the combining method, a maximum value or a minimum value may be selected. Furthermore, the average is not limited to a simple average, and a load average or the like may be used.

Here, the reason why the driver request estimated value and the index of the own vehicle driving force estimated value are synthesized is that, for example, when the vehicle is running steadily on an expressway, the throttle opening and its change amount are small, but the driving force is small. Is big. That is, the vehicle is running with high sports properties. Therefore, in order to determine whether or not the driver wants to run sports, it is understood that the throttle opening and the change amount thereof are insufficient, and that the estimated value of the own vehicle driving force is necessary.

Subsequently, the flow advances to S20, where it is determined whether or not the obtained index exceeds a predetermined value k. That is, it is determined based on the obtained index whether the driver intends to relax or run in sports, and appropriate control is performed according to the determination.

When the result in S20 is affirmative, the control mode is determined to be the relax control mode, and the program proceeds to S22, in which the running condition is determined using the estimated gradient θ of the running road. Specifically, this is performed by comparing the gradient θ with the aforementioned predetermined values α and β.

When it is determined in S22 that the gradient θ is equal to or greater than the predetermined value α, it is determined that the vehicle is climbing a slope, and the process proceeds to S24, where a ratio is set based on the instantaneous margin driving force.

Referring to FIG. 12, the instantaneous marginal driving force is a term coined by the inventors, and the accelerator is fully opened (or a predetermined opening degree) with the current ratio and engine speed. Is the difference between the full-open output that is output at the time and the actual engine torque that the engine is actually outputting at the current ratio and the engine speed, and the state of the driving force change with respect to the vehicle margin or accelerator opening ( (A so-called good accelerator). Therefore, it is a concept different from the generally defined margin driving force (difference between the full-open output and the running resistance).

FIG. 13 shows the control when it is determined that the driver intends to relax and the vehicle is in an uphill condition. As shown in the figure, the ratio is set using the model shown in the upper part of the figure so that the instantaneous excess driving force becomes the target instantaneous excess driving force in the lower part of the figure.

According to the experiments conducted by the inventors, the target instantaneous margin driving force is such that the maximum acceleration is about 0.1 G and the vehicle weight is 1 t.
In this case, about 50 to 100 kgf was suitable for relaxing uphill driving.

Specifically, the target instantaneous margin driving force is calculated as shown in FIG.
As shown in FIG. 15 and a three-dimensional map representing the driving state, the driving state estimation index is set variably, and the driving state estimation index increases, in other words, decreases so that the driver does not want the driving force. And the vehicle speed V is variably set. That is, since a larger acceleration / deceleration performance is required at a low vehicle speed than at a high vehicle speed, the target instantaneous margin driving force is set to increase. By setting in this way, it is possible to reduce noise generated when the engine speed increases at a high vehicle speed, and it is possible to reduce the discomfort.

Next, the process proceeds to S26, where the set ratio is indexed into a numerical value from 1 to 5 points by an appropriate method.

On the other hand, when it is determined in S20 that the estimated gradient θ is equal to or smaller than the predetermined value α, it is determined that the traveling condition is downhill, and the process proceeds to S28.

FIG. 16 is an explanatory block diagram showing the control. Using the model shown in the upper part of FIG. 16, the ratio is set so that the driving force matches the running resistance or the target driving force becomes zero. . That is, as shown in FIG. 17, when the vehicle is descending a hill, the engine brake driving force fe acts on the vehicle in the deceleration direction and the running resistance R acts on the vehicle in the acceleration direction, but the vehicle travels with the engine braking force (shown by -fe) when the throttle is fully closed. The ratio is determined so that the resistances R match. Next, the process proceeds to S30, where the determined ratio is indexed.

If it is determined in step S22 that the estimated gradient θ is larger than the predetermined value β and equal to or smaller than α, it is determined that the traveling condition is on a flat ground, and the flow advances to step S32.

[0120] Explaining the flatland control, the superiority of drivability on a flatland is not as remarkable as on an uphill or downhill. Therefore, in this embodiment, the DBW ( Pulse motor 1
8 and the throttle control unit 400) to control the driving force by controlling the throttle opening. More specifically, the instantaneous margin driving force is controlled by a ratio, and the driver's required driving force is controlled by a throttle opening.

FIG. 18 is a subroutine flowchart showing the control. The program shown in FIG.
It is executed every one second.

When the control shown in FIG. 18 is summarized, the driver's required driving force is compared with the actual driving force, and the throttle opening is opened and closed by a predetermined amount according to the comparison result. Next, the total efficiency ηtotal of the engine and the transmission is calculated and compared with the previous value. For example, if the efficiency is increased and the previous time was the subtraction control of the target instantaneous margin driving force, the efficiency is further increased by the decreasing direction control. Judge and further subtract. As a result, the ratio follows the high geared direction. On the other hand, when the efficiency is reduced by the subtraction control, the control is switched to the addition control. As described above, the change in the total efficiency and the control direction of the target instantaneous margin driving force are determined, and the control is performed so that high total efficiency is obtained.

The following description is based on the premise of the above.
0, it is determined whether or not the flatland fuel efficiency control is currently being executed,
If affirmed, the process proceeds to S182, where it is determined whether the actual driving force is greater than the driver's requested driving force.
Proceeding to 184, the current throttle opening th is
a is added, and the throttle valve 14 is controlled in the opening direction so as to have the added value.

If the result in S182 is NO, S18
6 to the predetermined value tha from the current throttle opening th.
Is subtracted, and the throttle valve 14 is controlled in the closing direction so as to have the subtracted value. When the result in S180 is NO, the processing from S182 to S186 is skipped.

Next, the program proceeds to S188, in which the target instantaneous marginal driving force (referred to as "Fie-obj") is reduced toward zero by a predetermined amount, and the program proceeds to S190. First, the efficiency ηeng and ηtm of the engine 10 and the transmission 24 are calculated.

More specifically, the engine efficiency ηeng and the transmission ηtm are calculated by a map search. More specifically, the engine efficiency ηeng is equal to the engine torque Te.
(Calculated in S102) and a map which is appropriately set in advance so that the fuel consumption rate is the best with the engine speed Ne is searched for and determined, and the transmission ηtm is similarly determined to be the best in the NDR and NDN. Thus, a map which is appropriately set in advance is searched for and obtained.

Then, the obtained engine efficiency ηeng is multiplied by the transmission ηtm to obtain a total efficiency ηto
tal, and calculates the calculated value (current value) as the previous value
Replace with the previous value and update the previous value. In the first program loop, an appropriate value (for example, 0) is set as the previous value. The total efficiency ηtotal indicates the efficiency of the engine and the transmission at the fuel consumption rate.

Then, the program proceeds to S192, in which the current instantaneous driving force (referred to as "Fie") is read and similarly updated by replacing it with the previous value.

Next, the routine proceeds to S194, where the present value (calculated value)
Is greater than or equal to the previous value, and if affirmative, S1
The program proceeds to 95, where it is determined whether the target instantaneous marginal driving force sequential addition control (S196) was performed last time. When affirmative in S195, the process proceeds to S196, in which the predetermined value x is added to the target instantaneous margin driving force, and when negative, S197 is performed.
Then, the predetermined value x is subtracted from the target instantaneous margin driving force.

If the result in S194 is NO, S19 is reached.
8, similarly, it is determined whether or not the target instantaneous margin driving force sequential addition control was performed last time, and if affirmative, S19 is performed.
7 and, if not, the flow proceeds to S196.

As described above, considering the previous processing, S19
6, by performing the processing of S197, it is possible to control to a position where η total becomes large. That is, as shown in FIG. 19, by increasing or decreasing the target instantaneous margin driving force, the target instantaneous margin driving force value Fηmax at which the total efficiency is the best in the fuel consumption rate can be searched and trapped at that point.

Here, subtracting the predetermined value x from the target instantaneous margin driving force value means adding the predetermined value x to the target instantaneous margin driving force value on the high ratio side by an amount corresponding to the transmission ratio corresponding to the predetermined value x. This means that the driving force is controlled by controlling the transmission ratio to the low ratio side by an amount corresponding to the predetermined value x.

That is, driving the target instantaneous margin driving force value in the zero direction means driving the throttle opening in the full opening direction regardless of the accelerator opening. The engine efficiency at which the fuel consumption rate is the best is usually located near the throttle fully open, and if the transmission efficiency of the transmission is almost constant, the best point should be obtained by changing the target instantaneous margin driving force value toward zero. Can be. Therefore, FIG.
By trapping the best point Fηmax as shown in
The fuel consumption rate can be optimized.

Returning to the description of FIG. 2, when the result in S20 is NO, it is determined that the driver wants to run sports, and
Proceeding to 34, a ratio is set using the instantaneous margin driving force or driving force, and proceeding to S36 for indexing. It should be noted that the characteristic of this control is mainly in the relaxed traveling, and a detailed description thereof will be omitted.

Then, the program proceeds to S38, in which the obtained index is converted into a ratio control output index, and the program proceeds to S40, where it is applied to the vertical axis of the characteristic shown in the figure, and the ratio of the horizontal axis (ratio multiplied value) is calculated. Next, in S42, the ratio is determined by multiplying the obtained ratio by the base ratio map value (searched from the throttle opening and the vehicle speed).

Now, returning to the description of the flowchart of FIG. 8, the processing of S126 will be described.

This processing is based on the above-mentioned traveling conditions (uphill and downhill).
Unlike the determination, the slip level of the traveling road is determined, and the ratio control is performed accordingly. Specifically, the state of the traveling road is determined into a plurality of states, and ratio control is performed based on the result.

FIG. 20 is a subroutine flowchart for explaining the processing of S126, and FIG. 21 is a graph showing a change in the driving force corresponding to the gradient with respect to the traveling road state.

Referring to the flow chart of FIG.
At 200, peak hold and time subtraction of the obtained estimated gradient equivalent driving force are performed. More specifically, the obtained estimated gradient-equivalent driving force is held and subtracted by a predetermined amount each time the program loop shown in the drawing is performed, and when a larger value is obtained, it is replaced.

The processing of S200 will be described with reference to FIG. 21. When the vehicle spins or slips, the value of sin θ obtained by the above-described processing, that is, the value of the estimated gradient equivalent driving force (msin θ) is negative. Is calculated with a peak. In this process, the value of the driving force corresponding to the estimated gradient at the peak is held and a value obtained by subtracting time ((msinθ))
hd), and using this, the state of the traveling road is determined.

Subsequently, the program proceeds to S202, in which it is determined whether or not the absolute value of the difference between the time-subtracted value and the gradient-equivalent driving force exceeds a predetermined value B. That is, the attenuation curve (shown by a in FIG. 21) obtained by subtracting the estimated gradient-equivalent driving force at the peak time is less than the value obtained by subtracting the predetermined value B from the estimated gradient-equivalent driving force (shown by b in FIG. 21). It is determined whether or not. When the result in S202 is affirmative, it is determined that the vehicle is traveling on a low μ road with a small gripping force (coefficient of friction), and the process proceeds to S204, where the driving force corresponding to the estimated gradient corresponding to the peak is attenuated again with the time. The absolute value of the difference from the equivalent driving force (msinθ) is determined, and it is determined whether the difference is equal to or greater than a predetermined value C. That is, an attenuation curve obtained by subtracting the estimated gradient-equivalent driving force at the peak time with respect to time (indicated by a in FIG. 21).
Is smaller than the value obtained by subtracting the predetermined value C from the estimated gradient equivalent driving force (indicated by c in FIG. 21).

Next, the routine proceeds to S206, where the intake air temperature sensor 10
7 is read as being considered to be equivalent to the outside temperature,
Proceeding to 8, it is determined whether the intake air temperature (outside air temperature) is less than a specified value. The specified value is set to an appropriate value that can determine whether or not the road surface is frozen. If affirmative in S208, S2
The program proceeds to S10, where the vehicle is judged to be on a frozen road, and instantaneous margin driving force control is performed at the time of judging the frozen road. Is determined to be a rough road, and instantaneous margin driving force control is performed when the rough road is determined.

The process such as S212 will be described. A target instantaneous driving force is searched for and obtained from the preset characteristics using the current vehicle speed V. FIG. 23 is a graph showing the characteristics.

As shown in FIG. 23, the target instantaneous margin driving force characteristics were set separately for the determination of the frozen road and the determination of the bad road. That is, at the time of judging an icy road, the instantaneous margin driving force control is performed such that the target value is set lower than the normal time, and at the time of judging a bad road, the instantaneous margin driving force control of the target value set higher than the icy road is performed. I made it.

More specifically, as shown in FIG. 13, the difference is obtained by subtracting the target instantaneous margin driving force from the instant margin driving force.
A value obtained by multiplying the value by a coefficient k is input to a preset conversion table as shown in the figure as an input u, and an output x indicating an index is obtained. Next, the obtained output x is input to a previously set conversion table as shown in FIG.
Ask for.

As described above, the driving force control is performed with the instantaneous marginal driving force representing the goodness of the accelerator opening change as the target value, and the target value is set to a value lower than the normal instantaneous marginal driving force setting. As a result, the generation of abrupt driving force on frozen roads and rough roads is suppressed, and the occurrence of spins and the like is prevented.

On the other hand, when the result in S202 is NO, S21.
Proceeding to 4, it is determined whether or not the absolute value of the gradient equivalent resistance (msinθ) is less than a predetermined value A. When a negative determination is made in S214, similarly, it is determined that the vehicle is traveling on a low μ road with a small gripping force, and the process proceeds to S204 and thereafter to perform the low μ road control, and when affirmative, the process proceeds to S216. And the control is performed based on the driving force at the time of the normal determination.

Specifically, the target driving force is determined in accordance with the characteristics shown in FIG. 22, the actual driving force calculated from the target driving force is subtracted to obtain a difference, and the difference is multiplied by a coefficient k. To set the ratio as follows.

More specifically, an engine torque generated from the engine speed Ne and the accelerator opening θacc is determined, a target driving force is determined from the torque and the vehicle speed V, and a ratio is set so as to be the determined target driving force. Control.

When the result in S204 is NO, S218 is reached.
Then, it is determined that the road is a wet road, and the driving force control at the time of determining the wet road is performed.

Specifically, the driving force characteristic at the time of wet road determination shown in the lower part of FIG.
The same ratio setting as in the case of the normal road determination driving force control is performed.
As described above, when the wet road is determined, the ratio is set based on the driving force set to have a target value lower than the driving force control during the normal road control.

Returning to the description of the flow chart of FIG.
The first mountain / city area determination will be described.

FIG. 24 is a subroutine flowchart showing the processing, and FIG. 25 is an explanatory diagram for explaining the processing.

In this control, the area where the vehicle is traveling is determined to be either a mountain or an urban area using a concept of a mountain / city area determining function fmount (θn). Alternatively, the adjustment gains k1 and k2 of the driving force are appropriately changed. That is, the control responsiveness (the speed at which the control value converges to the target value) is changed according to the driving situation.

FIG. 26 is a graph showing the characteristics of the mountain / city area determination function. The mountain / city determination function is a function indicating the degree of mountain or the degree of city in the area where the vehicle is currently traveling. Specifically, the characteristic shown in FIG. Search by value.

Accordingly, the characteristics of the city area determining function are such that when the vehicle is traveling on a mountain road with a steep gradient, the integrated value becomes a large value and the vehicle is traveling on an urban area with a gentle gradient. At that time, the integrated value was set to a small value.

The target driving force is obtained by retrieving the characteristics shown in FIG. 27 from the mountain / city area determination function. As a result, when the value of the mountain / town area determination function is large, that is, when the mountainous tendency is high, the running resistance and the driving force (engine braking force) match (target driving force = 0), and the change in vehicle speed on a downhill road is small. . Also, when the value of the mountain / city area determination function is small, that is, when the tendency of the city area is high, the target driving force increases.

Therefore, on a downhill in a mountainous area, the target driving force is set to 0, and the running resistance and the engine braking force are made equal to prevent a vehicle speed increase on the downhill. On the other hand,
On a downhill in an urban area, the same engine braking performance as usual reduces the sense of discomfort with other vehicles traveling forward and backward.

Hereinafter, a description will be given with reference to a flowchart of FIG. 24. In S300, the long span estimated gradient value θ
Read long.

Subsequently, the flow advances to S302, in which a function for determining a mountain / city area is determined from the long span estimation gradient θ long, and S3 is determined.
It is determined whether or not the mountain / city area determination function obtained by proceeding to 04 is less than the predetermined value A or exceeds the predetermined value B. Here, the predetermined values A and B are an overflow limiter and an underflow limiter, respectively.

When the result in S304 is affirmative, the program proceeds to S306, in which a mountain / city area determination function is held. Also, S3
When the result in S04 is negative, that is, when fmount (θn) is equal to or more than the predetermined value A or equal to or less than B, the process proceeds to S308, and the limit value A or B is set to the mountain / city area determination function fmount (θ
n) and hold.

Subsequently, the flow proceeds to S310, in which it is determined whether or not the determined mountain / city area determination function exceeds a predetermined value C. Here, the predetermined value C is a mountain judgment threshold, and the corner resistance R
A value obtained by attenuating the peak hold value of c with time is used. FIG. 28 is a graph showing characteristics of the mountain determination threshold.

As shown in FIG. 28, the mountain judgment threshold C
Is obtained using a value obtained by attenuating the peak hold value of the corner resistance Rc with time. Further, as shown in the figure, the mountain determination threshold value C is set to be inversely proportional to the corner resistance holddown value, whereby even when a relatively gentle slope continues, when there are many sharp corners, When the corner resistance is calculated to be high, the threshold value is set to a small value to make it easier to determine that the mountain is a mountain.

Returning to the flow chart of FIG.
If affirmative at 0, the process proceeds to S312 to determine whether the vehicle is traveling on a mountain road, and proceeds to S314 to determine whether the ratio control during downhill is being performed.

If the result in S314 is affirmative, the program proceeds to S316, in which the target driving force is set to zero. This is because the control is performed such that the vehicle can descend at a constant speed even if the downhill gradient changes so as to suppress the speed change on a mountain road with abrupt changes in undulation.

Then, the program proceeds to S318, in which the instantaneous margin driving force or the driving force power adjustment gains k1 and k2 are set to mountain preset values, respectively. If a negative determination is made in S314, the process skips S316 and proceeds to S318.

If the result in S310 is NO, S32 is reached.
The process proceeds to 0 to determine that the vehicle is traveling in an urban area, and proceeds to S322 to determine whether or not the vehicle is performing driving force control (ratio control during descent).

When the result in S322 is affirmative, the program proceeds to S324, in which the target driving force is set to a specified value (for example, a positive value such as 5 kgf). This is because, on a general road downhill in an urban area or the like, a slight acceleration is more convenient due to the flow of other vehicles, and the ratio control is performed in a direction in which a slightly positive driving force is generated.
However, if the brake is operated even once in this state, the specified value is set to 0, and the ratio control is performed so that the speed change is reduced.

In the process of S324, even if the target driving force is applied while maintaining the ratio at that time and using an appropriate map, a linear vehicle speed-engine speed characteristic equivalent to that of the manual transmission is obtained. good.

Then, the process proceeds to S326, where the gains k1, k2
Is defined as the city area specified value. If the result in S322 is negative, S324 is skipped and the routine proceeds to S326.

Note that the mountain specified values of the gains k1 and k2 are both set higher than the city specified value, and the ratio control is performed more responsively when traveling on a mountain road than in city driving.

Since this embodiment is configured as described above, it is possible to realize speed ratio control according to the driver's intention, and to improve drivability.

As described above, in this embodiment,
In a control device for an automatic transmission for a vehicle, operating state detecting means (a water temperature sensor 106, a throttle opening sensor 10) for detecting an operating state of the vehicle and an internal combustion engine mounted thereon.
8, accelerator opening sensor 110, brake switch 11
2, a vehicle speed sensor 122, a steering angle sensor 128, etc.), running resistance calculation means (integrated control unit 300, S108 in FIG. 8) for calculating running resistance R of the vehicle based on the detected driving state, The driving force calculating means (the integrated control unit 300, S14 in FIG. 2, and S104 in FIG. 8) for calculating the driving force F output from the vehicle based on the driving state obtained by the driving resistance R and the driving force F Gradient estimating means (integral control unit 300, S10 in FIG. 2, S11 in FIG. 8) for estimating the gradient θ of the traveling road on which the vehicle is traveling on the basis of
0), determining means (integrated control unit 300, S22 in FIG. 2) for comparing the estimated gradient θ with predetermined values (α and β) to determine the running state of the vehicle, Ne is calculated as the maximum driving force that can be output, and a driving force difference from the driving force (an instantaneous marginal driving force) is calculated. Speed ratio setting means (integral control unit 300, S24 to S40 in FIG. 2 and block diagram in FIG. 13) for setting a speed ratio so as to provide a marginal driving force, and the vehicular automatic transmission based on the set speed ratio. The transmission ratio determining means (integrated control unit 300, S42 in FIG. 2) for determining the transmission ratio of the transmission is provided.

Further, the gear ratio setting means corrects the calculated driving force difference according to at least one of the estimated gradient and the detected vehicle speed (integrated control unit 300, FIG. 14). The target instantaneous margin driving force characteristic and the inclination characteristic of the target instantaneous margin driving force in FIG.

Further, the gear ratio setting means corrects the calculated driving force difference based on at least the throttle opening θth and the throttle opening change dth (integrated control section 300, S14 to S18 in FIG. 2). And the target instantaneous margin driving force characteristic shown in FIG. 14).

Further, the speed ratio setting means sets the speed ratio based on the calculated driving force difference and the running resistance when it is determined from the result of the determination that the vehicle is going downhill ( Integrated control unit 300, S24 to S4 in FIG.
0 and the block diagram of FIG. 16).

Further, the speed ratio setting means sets the speed ratio such that the calculated driving force difference matches the running resistance when the vehicle is determined to be on a downhill from the determination result. (Integrated control unit 300, S28 in FIG. 2,
The configuration was made as in S316 in FIG.

Further, when the speed ratio setting means determines that the vehicle is going downhill from the result of the determination, the speed ratio setting means sets the difference between the calculated driving force difference and the running resistance to a predetermined value. Setting the gear ratio (integrated control unit 300, FIG. 2
S28 in FIG. 24 and S324 in FIG.

Further, operating state detecting means (water temperature sensor 106, throttle opening sensor 108, brake switch 112, vehicle speed sensor 122, steering speed sensor 122) for detecting the operating state of the vehicle and the internal combustion engine mounted thereon, including at least the throttle opening. Angle sensor 128, etc.), actual driving force calculating means (integrated control unit 300, S14 in FIG. 2, FIG. 7) for calculating an actual driving force output by the vehicle based on at least the throttle opening, and at least the detected A driver demand estimated value calculating means (an integrated control unit 300, S1 in FIG. 2) for calculating a driver demand estimated value based on the throttle opening.
(4, FIG. 7) (More specifically, at least the detected throttle opening is input to a first model that describes a driving state of the vehicle that has been set in advance, and a driver request estimated value is calculated based on the throttle opening. A driver request estimated value calculating means (integrated control unit 300, FIG.
S14 to S18 and FIG. 7), indexing means for indexing the calculated actual driving force and the driver's demand estimated value (more specifically, at least the detected throttle opening is set in advance. A self-vehicle, which calculates the required output of the driver by inputting the first model describing an ideal response characteristic of the vehicle and calculates a self-vehicle driving force from a driving force difference from the calculated driving force Driving force calculation means (integrated control unit 30
0, S14 to S18 in FIG. 2 and FIG. 4), and a driving state index calculating means (integrated control unit 300, FIG. 4) for calculating a driving state index by indexing the calculated driver request estimated value and the driving force of the own vehicle. 2, S14 to S18)), a running characteristic determining means (based on the index) for determining which of the first and second running characteristics, which are different in the driving force response, is required by the driver. Driving force control means for controlling the driving force of the vehicle via at least one of the output and the gear ratio of the internal combustion engine according to the integrated control unit 300, S16 to S20 in FIG. 2, and the determined traveling characteristics. (Integrated control unit 300, S in FIG. 2)
22, S32, and S180 to S190 in FIG. 18).

Further, when it is determined that the driver is requesting the second traveling characteristic, the driving force control means includes:
The gradient of the traveling road on which the vehicle is traveling is estimated, a target value of the driving force of the vehicle is set according to the estimated gradient, and feedback control is performed so as to reach the set target value (the integrated control unit 300, S24 and S28 in FIG. 2 and S2 in FIG.
00 to S218).

In the above description, a gradient may be added as an operation state index as shown in FIG.

[0182]

According to the present invention, drivability can be improved by realizing appropriate gear ratio control according to the gradient of the traveling road.

According to the present invention, it is possible to further improve the drivability by realizing appropriate gear ratio control according to the gradient of the traveling road.

According to the present invention, it is possible to improve the drivability by realizing the speed ratio control according to the traveling road gradient and the demand of the driver.

According to the present invention, the drivability can be improved by realizing the speed ratio control according to the gradient of the traveling road, particularly, downhill.

According to the fifth aspect, during downhill traveling, the gear ratio control suitable for the driver's intention can be realized, and the drivability can be improved.

According to the present invention, the drivability can be improved by realizing gear ratio control suitable for the driver's intention during downhill running.

According to the present invention, it is possible to realize driving force control according to a driver's request while taking into account the traveling state of the own vehicle to achieve both improvement in drivability and improvement in fuel efficiency. it can.

According to the present invention, the driving force control according to the driver's request is realized while taking the running state of the own vehicle into consideration, thereby improving both drivability and fuel efficiency. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic diagram generally showing a control device such as an automatic transmission for a vehicle according to the present invention.

FIG. 2 is a flowchart showing the operation of the apparatus shown in FIG.

3 is an explanatory diagram of a physical quantity state estimation model based on the operation shown in the flowchart of FIG. 2;

FIG. 4 is a block diagram illustrating calculation of a driver request in the block diagram of FIG. 3;

FIG. 5 is a block diagram showing calculation of a negative value of the throttle opening based on the estimated braking force in the block diagram of FIG. 4;

FIG. 6 is a block diagram showing calculation of a stepping time function of a throttle valve (accelerator pedal) and a brake pedal in the block diagram of FIG. 4;

FIG. 7 is a block diagram illustrating calculation of a host vehicle gain in the block diagram of FIG. 3;

FIG. 8 is a block diagram showing a gradient estimating operation of the flow chart of FIG. 2;

FIG. 9 is a block diagram illustrating characteristics of a filter used in a sensor output reading process of the flow chart of FIG. 8;

FIG. 10 is a block diagram showing a corner resistance calculation process in the flow chart of FIG. 8;

FIG. 11 is an explanatory diagram showing indexing and averaging operations of the flow chart of FIG. 2;

12 is a block diagram illustrating calculation of an instantaneous margin driving force used in the uphill control in the flowchart of FIG. 2;

FIG. 13 is a block diagram illustrating climb control in the flowchart of FIG. 2;

FIG. 14 is a graph illustrating characteristics of an instantaneous margin driving force used in the uphill control in the flowchart of FIG. 2;

15 is a graph illustrating characteristics of an instantaneous margin driving force used in the uphill control in the flowchart of FIG. 2;

FIG. 16 is a block diagram illustrating downhill control in the flowchart of FIG. 2;

FIG. 17 is also an explanatory diagram for explaining the descending slope control in the flowchart of FIG. 2;

FIG. 18 is a flowchart illustrating flatland control in the flowchart of FIG. 2;

FIG. 19 is an explanatory diagram illustrating the processing of FIG. 18;

20 is a flowchart showing a subroutine for low-μ road control in FIG. 8;
It is a chart.

FIG. 21 is a time chart for explaining the processing of the flow chart of FIG. 20;

FIG. 22 is a graph showing driving force characteristics used in the processing of the flow chart of FIG. 20;

FIG. 23 is a graph showing target instantaneous margin driving force characteristics used in the processing of the flow chart of FIG. 20;

FIG. 24 is a subroutine flowchart of a mountain / urban area determination operation in the flowchart of FIG. 2;

FIG. 25 is a graph illustrating the processing of the flowchart of FIG. 24;

FIG. 26 is a graph showing characteristics of a mountain / city area determination function fmount θn used in the flow chart of FIG. 24;

FIG. 27 is a graph showing characteristics of a target driving force retrieved from a mountain / city area determination function used in the flow chart of FIG. 24;

FIG. 28 is a predetermined value C used in the flow chart of FIG.
FIG. 6 is a graph showing the characteristics of FIG.

29 is an explanatory diagram showing another example of the indexing and averaging operation of the flow chart of FIG. 2, similar to FIG. 11;

[Explanation of symbols]

Reference Signs List 10 internal combustion engine (main body) (engine (main body)) 14 throttle valve 16 accelerator pedal 18 pulse motor 24 belt-type continuously variable transmission (automatic transmission; CVT. Transmission) 29 vehicle 100 transmission control unit 104 absolute pressure sensor 107 intake temperature Sensor 108 Throttle opening sensor 112 Brake switch 114 Speed sensor 122 Vehicle speed sensor 128 Steering angle sensor 200 Engine control unit 300 Integrated control unit 400 Throttle control unit 500 Low-pass filter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) F16H 59:70 (72) Inventor Osamu Nagatani 1-4-1 Chuo, Wako-shi, Saitama Japan Honda Co., Ltd. F-term in the laboratory (reference) 3D041 AA31 AC15 AC19 AD00 AD02 AD04 AD05 AD10 AD14 AD31 AD41 AD51 AE04 AE32 AF01 AF09 3G093 AA06 BA15 CA05 CB06 CB07 DA01 DA03 DA04 DA05 DA06 DA07 DB00 DB05 DB11 DB15 DB18 EA09 EB03 EC02 EC04 AA04 BA14 CA21 FB31 GC03 GC13 GC23 GC43 GC44 GC46 GC72 GD11 HA11 LA01

Claims (8)

[Claims] 1. A control device for an automatic transmission for a vehicle, comprising: a. Operating state detecting means for detecting an operating state of the vehicle and the internal combustion engine mounted thereon; b. Running resistance calculating means for calculating running resistance of the vehicle based on the detected driving state; c. Driving force calculating means for calculating a driving force output by the vehicle based on the detected driving state; d. Gradient estimating means for estimating the gradient of a traveling road on which the vehicle is traveling, based on the calculated traveling resistance and driving force; e. Determining means for comparing the estimated gradient with a predetermined value to determine a traveling state of the vehicle; f. A maximum driving force that the vehicle can output at the current gear ratio is calculated to calculate a driving force difference from the driving force, and the calculated driving force difference becomes a predetermined value according to the determination result. Speed ratio setting means for setting a speed ratio in the vehicle; and g. A speed ratio determining means for determining a speed ratio of the vehicle automatic transmission based on the set speed ratio, a control device for the vehicle automatic transmission. 2. The apparatus according to claim 1, wherein the gear ratio setting unit corrects the calculated driving force difference in accordance with at least one of the estimated gradient and the detected vehicle speed. A control device for an automatic transmission for a vehicle according to the above. 3. The apparatus according to claim 1, wherein the speed ratio setting means corrects the calculated driving force difference based on at least a throttle opening and a throttle opening change amount. Control device for automatic transmission for vehicles. 4. The gear ratio setting means sets the gear ratio based on the calculated driving force difference and the running resistance when the vehicle is determined to be on a downhill from the determination result. The control device for a vehicle automatic transmission according to any one of claims 1 to 3, wherein: 5. The speed ratio setting means sets the speed ratio such that the calculated driving force difference matches the running resistance when the vehicle is determined to be downhill from the determination result. The control device for an automatic transmission for a vehicle according to claim 4, wherein the control is performed. 6. The speed ratio setting means, when it is determined from the determination result that the vehicle is on a downhill, such that the difference between the calculated driving force difference and the running resistance becomes a predetermined value. The control device for an automatic transmission for a vehicle according to claim 4, wherein the speed ratio is set. 7. A method according to claim 1, wherein Operating state detecting means for detecting an operating state of the vehicle and the internal combustion engine mounted on the vehicle, including at least the throttle opening; b. Actual driving force calculating means for calculating an actual driving force output by the vehicle based on at least the throttle opening; c. A driver required estimated value calculating means for calculating a driver required estimated value based on at least the detected throttle opening; d. Indexing means for indexing the calculated actual driving force and the driver's demand estimated value; e. Traveling characteristic determining means for determining which one of at least the first traveling characteristic and the second traveling characteristic which are different in the driving force response from the driver based on the index; f. A control device for controlling a driving force of the vehicle via at least one of an output of the internal combustion engine and a gear ratio in accordance with the determined traveling characteristics. 8. When it is determined that the driver is requesting the second traveling characteristic, the driving force control unit estimates a gradient of a traveling road on which the vehicle is traveling, and estimates the estimated gradient. 8. The control device for a vehicle according to claim 7, wherein a target value of the driving force of the vehicle is set according to the feedback control, and feedback control is performed so as to reach the set target value.