JP6935057B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device, and particularly to a steering device, a drive source that generates torque for driving the drive wheels, a generated torque control mechanism that controls the generated torque of the drive source, and left and right wheels. The present invention relates to a vehicle control device including a braking device capable of applying different braking forces and a processor.

Conventionally, there is known a technique (for example, an electronic stability control) for controlling the behavior of a vehicle in a safe direction when the behavior of the vehicle becomes unstable due to slipping or the like. Specifically, it is known that when the vehicle is cornering or the like, it is detected that the vehicle has understeer or oversteer behavior, and an appropriate deceleration is applied to the wheels so as to suppress them. ing.

In addition, unlike the control for improving safety in a driving state where the behavior of the vehicle becomes unstable as described above, acceleration / deceleration linked to the steering wheel operation that operates from the daily driving area is automatically performed, and the limit is reached. A vehicle motion control device that reduces skidding in the driving region is known (see, for example, Patent Document 1). In particular, Patent Document 1 discloses a vehicle motion control device including a first mode for controlling acceleration / deceleration in the front-rear direction of the vehicle and a second mode for controlling the yaw moment of the vehicle. There is.

Japanese Unexamined Patent Publication No. 2010-162911

The control performed in the first mode as described in Patent Document 1 (hereinafter, appropriately referred to as "first control") is typically when the steering angle is increasing (that is, that is). When the steering wheel is cut (when the steering wheel is cut), it is performed so as to give a deceleration to the vehicle. On the other hand, the control performed in the second mode as described in Patent Document 1 (hereinafter, appropriately referred to as "second control") is typically when the steering angle is decreasing. (That is, when the steering wheel is turned back and forth), the yaw moment is applied in the direction opposite to the yaw rate generated in the vehicle.

Here, for example, when the vehicle travels in an S-shaped corner, the first control is first executed when the steering angle is increased (during the turning operation), and then when the steering angle is decreased (during the turning back operation). The second control is executed first, and then the first control tends to be further executed when the steering angle is increased (during the cutting operation). In this case, when the steering operation is switched from the turning back operation to the turning operation, that is, when the steering angle crosses 0, it is desirable to appropriately switch from the second control to the first control, but the steering angle is Both the first and second controls may be performed when near zero. That is, when the second control continues to be executed even after the steering angle straddles 0, the first control is repeatedly executed while the second control is being executed.

When both the first and second controls are executed in this way, the control intervention of the vehicle as a whole becomes excessive, which may give the driver a sense of discomfort. For example, in an S-shaped corner, when the steering wheel is turned back to the right from the state where it is operated to the left, the second control causes the vehicle to turn straight, that is, the vehicle turns to the right. A yaw moment is applied to the vehicle to facilitate it. After that, when the steering wheel is turned to the right across the neutral position (steering angle 0), the first control gives the vehicle a deceleration so that the vehicle can easily turn to the right. In such a series of situations, if the first control is repeatedly executed while the second control is being executed, the control for turning the vehicle to the right is doubly applied. , The vehicle may be oversteered to the right.

In addition, when the second control is suddenly terminated after the steering angle crosses 0, if the rise of the first control is gradual, the driver feels uncomfortable as if the control intervention suddenly decreased for the entire vehicle. there is a possibility.

The present invention has been made to solve the above-mentioned problems of the prior art, and for controlling the attitude of the vehicle, the control of giving the vehicle a deceleration based on the steering operation and the yaw moment are given to the vehicle. In the control device of the vehicle that controls the vehicle, the purpose is to prevent the control intervention from becoming excessive or suddenly decrease in the vehicle as a whole so as not to give the driver a sense of discomfort.

In order to achieve the above object, the vehicle control device of the present invention includes a steering device, a drive source that generates torque for driving the drive wheels, and a generated torque control mechanism that controls the generated torque of the drive source. , A vehicle control device equipped with a brake device capable of applying different braking forces to the left and right wheels and a processor. The processor rotates in the opposite direction to the yaw rate generated in the vehicle based on the turning state of the vehicle. The yaw moment is set, the braking device is controlled so that the set yaw moment is generated in the vehicle, and when the steering angle related value related to the steering angle of the steering device increases, the generated torque of the drive source is reduced. When the generated torque control mechanism is controlled in this way and the braking device generates a yaw moment, the amount of decrease in the generated torque of the drive source when the steering angle-related value increases is changed based on the yaw moment. It is characterized by being configured in.
In the present invention configured as described above, a braking device is set so that a yaw moment opposite to the yaw rate generated in the vehicle is set based on the turning state of the vehicle, and the set yaw moment is generated in the vehicle. When the yaw moment is generated, the decrease in the torque generated by the drive source when the steering angle-related value increases is changed based on the yaw moment. Therefore, when the control for applying the deceleration to the vehicle when the steering angle-related value is increasing and the control for applying the yaw moment to the vehicle based on the turning state are executed in combination, the deceleration is applied to the vehicle. The control intervention amount of the vehicle as a whole by the control applied and the control applied to the yaw moment can be adjusted to maintain the same level. As a result, it is possible to prevent the control intervention from becoming excessive and the control intervention from suddenly decreasing in the vehicle as a whole, and to prevent the driver from feeling uncomfortable.

Further, in the present invention, preferably, when the yaw moment generated by the braking device is the first value, the processor has a second value in which the yaw moment generated by the braking device is smaller than the first value. It is configured to reduce the amount of decrease in the generated torque of the drive source when the steering angle-related value increases, as compared with the case.
In the present invention configured as described above, when the yaw moment generated by the braking device is relatively large, the drive source is generated when the steering angle-related value increases as compared with when the yaw moment is relatively small. Since the amount of torque reduction is reduced, it is possible to adjust so that the control intervention amount of the vehicle as a whole by the control of applying the deceleration to the vehicle and the control of applying the yaw moment to the vehicle is maintained at the same level. As a result, it is possible to prevent the control intervention from becoming excessive in the vehicle as a whole and to prevent the driver from feeling uncomfortable.

Further, in the present invention, preferably, when the lowering speed of the yaw moment generated by the braking device is a third value, the processor preferably causes the lowering speed of the yaw moment generated by the braking device to be smaller than the third value. It is configured so that the amount of decrease in the generated torque of the drive source when the steering angle-related value increases is larger than that in the case of the fourth value.
In the present invention configured as described above, when the decrease rate of the yaw moment generated by the braking device is relatively large, the steering angle-related value is increased as compared with the case where the decrease rate of the yaw moment is relatively small. Since the amount of decrease in the generated torque of the drive source is increased, when the yaw moment generated by the braking device is suddenly decreased, the amount of decrease in the generated torque of the drive source is increased to give the vehicle a deceleration. It can be adjusted so that the control intervention amount of the vehicle as a whole by the control of the control and the control of applying the yaw moment to the vehicle is maintained at the same level. As a result, it is possible to suppress a sudden decrease in control intervention for the vehicle as a whole and to prevent the driver from feeling uncomfortable.

Further, in the present invention, it is preferable that the processor is configured to control the braking device so as to generate a set yaw moment in the vehicle when the steering angle-related value is decreasing.

Further, in the present invention, the turning state of the vehicle is preferably the steering speed acquired based on the detection value of the steering angle sensor that detects the steering angle of the steering device.

Further, in the present invention, preferably, the turning state of the vehicle is the difference between the actual yaw rate actually occurring in the vehicle and the target yaw rate set based on the detection value of the steering angle sensor that detects the steering angle of the steering device. It should be the rate of change of.

Further, in the present invention, preferably, when the steering device is operated across the neutral position and the braking device generates a yaw moment, the steering angle-related value increases based on the yaw moment. It is configured to change the amount of reduction in the generated torque of the drive source when the drive source is used.
In the present invention configured as described above, when the braking device generates a yaw moment even after the cutting operation is started across the neutral position from the state in which the steering device is being turned back. Based on the yaw moment, the decrease in the torque generated by the drive source when the steering angle-related value increases is changed. Therefore, when the steering operation is continuously performed from the turning back operation to the turning operation, for example, in an S-shaped corner, the control of giving the deceleration to the vehicle and the control of giving the yaw moment to the vehicle overlap. When implemented, it can be adjusted to maintain a comparable amount of control intervention for the vehicle as a whole. As a result, it is possible to prevent the control intervention from becoming excessive and the control intervention from suddenly decreasing in the vehicle as a whole, and to prevent the driver from feeling uncomfortable.

According to the vehicle control device according to the present invention, in the vehicle control device that controls the deceleration to be applied to the vehicle and the yaw moment to the vehicle based on the steering operation for the attitude control of the vehicle. As a whole, it is possible to suppress an excessive state of control intervention and a sudden decrease in control intervention so as not to give the driver a sense of discomfort.

It is a block diagram which shows the whole structure of the vehicle which mounted the control device of the vehicle according to the Embodiment of this invention. It is a block diagram which shows the electric structure of the control device of the vehicle by embodiment of this invention. It is a flowchart of the attitude control processing by 1st Embodiment of this invention. It is a flowchart of the addition deceleration setting process by 1st Embodiment of this invention. It is a map showing the relationship between the additional deceleration and the steering speed. This is a map showing the relationship between the yaw moment and the correction gain of the torque reduction amount. It is a flowchart of the target yaw moment setting process by 1st Embodiment of this invention. It is a time chart which showed the time change of the parameter about the vehicle attitude control when the vehicle equipped with the vehicle control device according to the 1st Embodiment of this invention makes a turn. It is a flowchart of addition deceleration setting processing by 2nd Embodiment of this invention. It is a map which showed the relationship between the decrease rate of a yaw moment and the correction gain of a torque reduction amount. It is a time chart which showed the time change of the parameter about the vehicle attitude control when the vehicle equipped with the vehicle control device according to the 2nd Embodiment of this invention makes a turn.

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

<System configuration>
First, the system configuration of the vehicle equipped with the vehicle control device according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing an overall configuration of a vehicle equipped with a vehicle control device according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 indicates a vehicle equipped with a vehicle control device according to the present embodiment. An engine 4 is mounted on the front portion of the vehicle body of the vehicle 1 as a drive source for driving the drive wheels (the left and right front wheels 2 in the example of FIG. 1). The engine 4 is an internal combustion engine such as a gasoline engine or a diesel engine, and in the present embodiment, it is a gasoline engine having a spark plug.

Further, the vehicle 1 has a steering angle sensor 8 for detecting the rotation angle of a steering column (not shown) connected to the steering wheel 6, a vehicle speed sensor 10 for detecting the vehicle speed, and a yaw rate sensor 12 for detecting the yaw rate. Each of these sensors outputs the detected value to the PCM (Power-train Control Module) 14.

Further, the vehicle 1 is provided with a brake control system 18 that supplies brake fluid pressure to the wheel cylinders and brake calipers of the brake device 16 provided on each wheel. The brake control system 18 includes a hydraulic pump 20 that generates the brake hydraulic pressure required to generate a braking force in the brake device 16 provided on each wheel. The hydraulic pump 20 is driven by, for example, the electric power supplied from the battery, and generates the brake hydraulic pressure required to generate the braking force in each brake device 16 even when the brake pedal is not depressed. It is possible. Further, the brake control system 18 is a valve unit 22 for controlling the hydraulic pressure supplied from the hydraulic pump 20 to the brake device 16 of each wheel, which is provided in the hydraulic pressure supply line to the brake device 16 of each wheel. (Specifically, it is equipped with a solenoid valve). For example, the opening degree of the valve unit 22 is changed by adjusting the amount of electric power supplied from the battery to the valve unit 22. Further, the brake control system 18 includes a hydraulic pressure sensor 24 that detects the hydraulic pressure supplied from the hydraulic pressure pump 20 to the brake device 16 of each wheel. The hydraulic pressure sensor 24 is arranged, for example, at a connection portion between each valve unit 22 and a hydraulic pressure supply line on the downstream side thereof, detects the hydraulic pressure on the downstream side of each valve unit 22, and determines the detected value by PCM (Power-train). Output to Control Module) 14.
The brake control system 18 calculates the hydraulic pressure independently supplied to the wheel cylinders and brake calipers of each wheel based on the braking force command value input from the PCM 14 and the detection value of the hydraulic pressure sensor 24, and calculates the hydraulic pressures thereof. The rotation speed of the hydraulic pump 20 and the opening degree of the valve unit 22 are controlled according to the hydraulic pressure.

Next, with reference to FIG. 2, the electrical configuration of the vehicle control device according to the embodiment of the present invention will be described. FIG. 2 is a block diagram showing an electrical configuration of a vehicle control device according to an embodiment of the present invention.
The PCM14 (vehicle control device) according to the present embodiment generates the engine 4 based on the detection signals of the sensors 8 to 12 and 24 described above and the detection signals output by various sensors for detecting the operating state of the engine 4. A control signal is sent to control each part of the engine 4 that functions as a torque control mechanism (for example, a throttle valve, a turbo supercharger, a variable valve mechanism, an ignition device, a fuel injection valve, an EGR device, etc.) and a brake control system 18. Output.
The PCM 14 and the brake control system 18 each include one or more processors and various programs (basic control programs such as an OS) that are interpreted and executed on the processors, and application programs that are started on the OS and realize specific functions. ), And a computer equipped with an internal memory such as a ROM or RAM for storing programs and various data.
Although details will be described later, the PCM 14 and the brake control system 18 correspond to the vehicle control device in the present invention.

<Vehicle attitude control>
(First Embodiment)
Next, the specific control contents executed by the vehicle control device will be described.
First, with reference to FIG. 3, the overall flow of the attitude control process performed by the vehicle control device in the first embodiment of the present invention will be described. FIG. 3 is a flowchart of the attitude control process according to the first embodiment of the present invention.

The attitude control process of FIG. 3 is activated when the ignition of the vehicle 1 is turned on and the power is turned on to the control device of the vehicle, and is repeatedly executed at a predetermined cycle (for example, 50 ms).
When the attitude control process is started, as shown in FIG. 3, in step S1, the PCM 14 acquires various sensor information regarding the driving state of the vehicle 1. Specifically, the PCM 14 is used for the steering angle detected by the steering angle sensor 8, the vehicle speed detected by the vehicle speed sensor 10, the yaw rate detected by the yaw rate sensor 12, the hydraulic pressure detected by the hydraulic pressure sensor 24, and the transmission of the vehicle 1. The detection signals output by the above-mentioned various sensors including the currently set gear stage and the like are acquired as information on the operating state.

Next, in step S2, the PCM 14 sets the target acceleration based on the operating state of the vehicle 1 including the operation of the accelerator pedal acquired in step S1. Specifically, the PCM14 has an acceleration corresponding to the current vehicle speed and gear stage from an acceleration characteristic map (created in advance and stored in a memory or the like) defined for various vehicle speeds and various gear stages. Select a characteristic map and refer to the selected acceleration characteristic map to determine the target acceleration corresponding to the current accelerator opening.

Next, in step S3, the PCM 14 determines the basic target torque of the engine 4 for achieving the target acceleration determined in step S2. In this case, the PCM 14 determines the basic target torque within the range of torque that can be output by the engine 4 based on the current vehicle speed, gear stage, road surface gradient, road surface μ, and the like.

Further, in parallel with the processes of steps S2 and S3, in step S4, the PCM 14 executes the additional deceleration setting process, and generates deceleration in the vehicle 1 based on the value related to the steering angle (steering angle related value). The torque reduction amount required to control the vehicle attitude is determined. In the present embodiment, a case where the steering angle is used as the steering angle-related value will be described. The details of the additional deceleration setting process will be described later.

Next, in step S5, the PCM 14 executes the target yaw moment setting process and sets the target yaw moment to be given to the vehicle 1 in order to control the vehicle posture based on the turning state of the vehicle 1. In the present embodiment, the case where the steering speed is used as the turning state will be described. The details of the target yaw moment setting process will be described later.

After the processing of steps S3 and S5, in step S6, the PCM 14 determines the final target torque based on the basic target torque determined in step S3 and the torque reduction amount determined in step S4. For example, the PCM 14 uses a value obtained by subtracting the torque reduction amount from the basic target torque as the final target torque.

Next, in step S7, the PCM 14 controls the engine 4 so as to output the final target torque set in step S6. Specifically, the PCM 14 has various state quantities (for example, air filling amount, fuel injection amount, etc.) required to realize the final target torque based on the final target torque set in step S6 and the engine rotation speed. The intake air temperature, oxygen concentration, etc.) are determined, and each actuator that drives each component of the engine 4 is controlled based on the state quantities thereof. In this case, the PCM 14 sets a limit value or a limit range according to the state amount, sets a control amount of each actuator such that the state value complies with the limit value or the limit by the limit range, and executes control.
More specifically, the PCM 14 reduces the generated torque of the engine 4 by delaying (retarding) the ignition timing of the spark plug 26 from the ignition timing when the basic target torque is used as it is as the final target torque. ..
When the engine 4 is a diesel engine, the PCM 14 reduces the generated torque of the engine 4 by reducing the fuel injection amount from the fuel injection amount when the basic target torque is used as the final target torque as it is.
The control for reducing the generated torque of the engine 4 performed by the PCM 14 corresponds to the above-mentioned "first control".

Next, in step S8, the brake control system 18 controls the brake device 16 so as to apply the target yaw moment set in step S5 to the vehicle 1. The brake control system 18 stores in advance a map that defines the relationship between the yaw moment command value and the rotation speed of the hydraulic pump 20, and by referring to this map, it is set in the target yaw moment setting process in step S5. The hydraulic pump 20 is operated at the rotation speed corresponding to the yaw moment command value (for example, by increasing the power supplied to the hydraulic pump 20, the hydraulic pressure pump 20 reaches the rotation speed corresponding to the braking force command value. (Increase the number of revolutions).
Further, the brake control system 18 stores, for example, a map that defines the relationship between the yaw moment command value and the opening degree of the valve unit 22 in advance, and corresponds to the yaw moment command value by referring to this map. The valve unit 22 is individually controlled so as to have an opening degree (for example, by increasing the power supplied to the solenoid valve, the opening degree of the solenoid valve is increased to the opening degree corresponding to the braking force command value). Adjust the braking force of the wheels.
The control performed by such a brake control system 18 corresponds to the above-mentioned "second control".
After step S8, the PCM 14 ends the attitude control process.

Next, the additional deceleration setting process according to the first embodiment of the present invention will be described with reference to FIGS. 4 to 6.
FIG. 4 is a flowchart of additional deceleration setting processing according to the first embodiment of the present invention, FIG. 5 is a map showing the relationship between additional deceleration and steering speed, and FIG. 6 is yaw moment and torque. It is a map which showed the relationship with the correction gain of the reduction amount.

When the additional deceleration setting process is started, in step S21, the PCM 14 determines whether or not the turning operation of the steering wheel 6 is in progress (that is, the steering angle (absolute value) is increasing).
As a result, when the cutting operation is in progress, the process proceeds to step S22, and the PCM 14 calculates the steering speed based on the steering angle acquired from the steering angle sensor 8 in step S1 of the attitude control process of FIG.

Next, in step S23, the PCM 14 determines whether or not _{the steering speed is equal to or higher than a predetermined threshold value S 1.}
As a result, when the steering speed is equal to _{or higher than the threshold value S 1} , the process proceeds to step S24, and the PCM 14 sets the additional deceleration based on the steering speed. This additional deceleration is a deceleration that should be added to the vehicle in response to the steering operation in order to control the vehicle attitude according to the driver's intention.
Specifically, the PCM 14 sets the additional deceleration corresponding to the steering speed calculated in step S22 based on the relationship between the additional deceleration shown in the map of FIG. 5 and the steering speed.
The horizontal axis in FIG. 5 indicates the steering speed, and the vertical axis indicates the additional deceleration. As shown in FIG. 5, when the steering speed is _{less than the threshold value S 1} , the corresponding additional deceleration is 0. That is, when the steering speed is _{less than the threshold value S 1} , the PCM 14 does not perform control for adding deceleration to the vehicle 1 based on the steering operation (specifically, reduction of the generated torque of the engine 4).
On the other hand, when the steering speed _{is equal to or higher than the threshold value S 1} , the additional deceleration corresponding to the steering speed gradually approaches a _{predetermined upper limit value D max as the steering speed increases.} That is, as the steering speed increases, the additional deceleration increases, and the rate of increase in the amount of increase decreases. This upper limit value D _max is set to such a deceleration that the driver does not feel that there is control intervention even if the deceleration is added to the vehicle 1 according to the steering operation (for example, 0.5 m / s ² ≈ 0). .05G).
Further, when the steering speed is equal to or higher than the _{threshold value S 2} which is larger than the _{threshold value S 1} , the additional deceleration is maintained at the _{upper limit value D max.}

Next, in step S25, the PCM 14 determines the torque reduction amount based on the additional deceleration set in step S24. Specifically, the PCM 14 determines the amount of torque reduction required to realize the additional deceleration due to the decrease in the generated torque of the engine 4 based on the current vehicle speed, gear stage, road surface gradient, etc. acquired in step S1. decide.

Next, in step S26, the PCM 14 causes the braking device 16 to generate a braking force by control based on the yaw moment set in the target yaw moment setting process, and determines whether or not the yaw moment is generated.
For example, the PCM 14 acquires the hydraulic pressure supplied to the brake device 16 of each wheel from the detection value of the hydraulic pressure sensor 24, and the yaw moment generated by the brake device 16 in the vehicle 1 based on the acquired hydraulic pressure. To estimate. Then, when the estimated yaw moment is equal to or higher than a predetermined threshold value, it is determined that the yaw moment is generated.

As a result, when the yaw moment is generated, the process proceeds to step S27, and the PCM 14 determines whether or not the steering angle has changed over 0 degrees based on the detection value of the steering angle sensor 8 (that is, the steering wheel 6 has changed. Whether or not it was operated so as to straddle the neutral position) is determined.

As a result, when the steering angle changes over 0 degrees, the process proceeds to step S28, and the PCM 14 is based on the yaw moment generated in the vehicle 1 by the control of the braking device 16 based on the yaw moment set in the target yaw moment setting process. , Correct the torque reduction amount.
Specifically, the PCM 14 has a correction gain of 1 or less corresponding to the yaw moment generated by the braking device 16 in the vehicle 1 based on the relationship between the yaw moment shown in the map of FIG. 6 and the correction gain of the torque reduction amount. The _{torque reduction amount is corrected by acquiring K 1} and multiplying the correction gain K ₁ by the torque reduction amount determined in step S25. As the yaw moment generated by the brake device 16 in the vehicle 1, the yaw moment estimated in step S26 can be used.
As shown in FIG. 6, the correction gain K ₁ is set to be smaller as the yaw moment is larger. That is, when the yaw moment generated by the brake device 16 is the first value, the torque reduction amount is corrected to be smaller than when the yaw moment is a second value smaller than the first value. ..
After step S28, the PCM 14 ends the additional deceleration setting process and returns to the main routine.

Further, in step S21, if not in turning operation of the steering wheel 6, or, in step S23, if the steering speed is less than the threshold value S _1, PCM 14, the additional deceleration setting without configuring additional deceleration Finish the process and return to the main routine. In this case, the torque reduction amount becomes 0.

Further, when the yaw moment is not generated by the control based on the yaw moment set in the target yaw moment setting process in step S26, or when the steering angle does not change over 0 degrees in step S27, the PCM14 sets the PCM14. The additional deceleration setting process is completed without correcting the torque reduction amount, and the process returns to the main routine. In this case, the torque reduction amount becomes the value determined in step S25.

Next, the target yaw moment setting process will be described with reference to FIG. 7.
As shown in FIG. 7, when the target yaw moment setting process is started, in step S31, the PCM 14 sets the target yaw rate and the target lateral jerk based on the steering angle and vehicle speed acquired in step S1 of the attitude control process of FIG. calculate.
Specifically, the PCM 14 calculates the target yaw rate by multiplying the steering angle by a coefficient corresponding to the vehicle speed. Further, the PCM 14 calculates the target lateral jerk based on the steering speed and the vehicle speed.

Next, in step S32, the PCM 14 calculates the difference (yaw rate difference) Δγ between the yaw rate (actual yaw rate) detected by the yaw rate sensor 12 acquired in step S1 of the attitude control process of FIG. 3 and the target yaw rate calculated in step S31. calculate.

Next, in step S33, the PCM14 is in the process of turning back the steering wheel 6 (that is, the steering angle is decreasing), and the change speed Δγ ′ of the yaw rate difference obtained by time-differentiating the yaw rate difference Δγ is determined. It is determined whether or not the predetermined threshold value Y _{1 or more is satisfied.}
As a result, when the switchback operation is performed and the yaw rate difference change rate Δγ ′ _{is equal to or greater than the threshold value Y 1} , the process proceeds to step S34, and the PCM 14 is opposite to the actual yaw rate of the vehicle 1 based on the yaw rate difference change rate Δγ ′. Set the surrounding yaw moment as the target yaw moment. Specifically, the PCM 14 _{calculates the magnitude of the target yaw moment by multiplying the predetermined coefficient C m1} by the change rate Δγ ′ of the yaw rate difference.

On the other hand, in step S33, when the steering wheel 6 is not being turned back (that is, the steering angle is constant or increasing), the process proceeds to step S35, and the PCM14 targets the actual yaw rate at the change speed Δγ ′ of the yaw rate difference. It is determined whether or not the direction is larger than the yaw rate (that is, the direction in which the behavior of the vehicle 1 becomes oversteer) and the change speed Δγ ′ of the yaw rate difference is equal to _{or more than the threshold value Y 1.} Specifically, the PCM14 is used when the yaw rate difference is decreasing when the target yaw rate is equal to or higher than the actual yaw rate, or when the yaw rate difference is increasing when the target yaw rate is less than the actual yaw rate. The rate of change Δγ ′ of the yaw rate difference is determined to be the direction in which the actual yaw rate becomes larger than the target yaw rate.

As a result, when the change rate Δγ ′ of the yaw rate difference is in the direction in which the actual yaw rate is larger than the target yaw rate and the change rate Δγ ′ of the yaw rate difference is the threshold value Y ₁ or more, the process proceeds to step S34, and the PCM 14 is set to the yaw rate difference. Based on the change speed Δγ', the yaw moment in the opposite direction to the actual yaw rate of the vehicle 1 is set as the target yaw moment.

After step S34 or in step S35, if the change rate Δγ ′ of the yaw rate difference is in the direction in which the actual yaw rate is larger than the target yaw rate or the change rate Δγ ′ of the yaw rate difference _{is less than the threshold value Y 1} , the process proceeds to step S36. , PCM 14 is cut back during operation of the steering wheel 6 (i.e. in the steering angle is decreased), and the steering speed is determined whether a predetermined threshold S ₃ or more.

As a result, if and steering speed in the switch-back is the threshold value S ₃ or more, the process proceeds to step S37, PCM 14, based on the target lateral jerk calculated in step S31, the actual yaw rate of the vehicle 1 the yaw moment opposite direction Set as the second target yaw moment.
Specifically, the PCM 14 calculates the magnitude of the second target yaw moment by multiplying the target lateral jerk by _{a predetermined coefficient C m2.}

After step S37, or, if cut is not being returning operation (i.e. the steering angle is in constant or increased) or steering speed of the steering wheel 6 is less than the threshold value S ₃ in step S36, the process proceeds to step S38, PCM 14 Sets the larger of the target yaw moment set in step S34 and the second target yaw moment set in step S37 as the yaw moment command value.
After step S38, the PCM 14 ends the target yaw moment setting process and returns to the main routine.

Next, the operation of the vehicle control device according to the first embodiment of the present invention will be described with reference to FIG. FIG. 8 is a time chart showing time changes of parameters related to vehicle attitude control when a vehicle equipped with a vehicle control device according to the first embodiment of the present invention makes a turn. In FIG. 8, chart (a) shows the steering angle of the vehicle making a turn, chart (b) shows the steering speed, chart (c) shows the target lateral jerk set based on the steering speed, and chart (d). ) Indicates the yaw moment generated in the vehicle 1 based on the target yaw moment set in the target yaw moment setting process, and the chart (e) shows the torque reduction amount set in the attitude control process.

As shown in the chart (a) of FIG. 8, the turning back operation is started at time t1 from the state where the steering wheel 6 is maintained at a certain steering angle, and the steering operation is performed so that the steering angle straddles 0 degrees at time t2. Is switched to the cutting operation, and it is assumed that the steering angle is kept constant after the time t3.

In this case, at the time t1 when the switchback operation is started, the target yaw moment for attitude control of the vehicle 1 is set, and the second control for applying the yaw moment to the vehicle 1 is started (chart (d)). reference). In a typical example, a steering operation switching back operation, and, in condition that the steering speed is the threshold value S ₃ or more is satisfied (step of FIG. 7 S36: Yes), PCM14, based on the target lateral jerk The (second) target yaw moment is set (step S37 in FIG. 7). After that, when the steering operation is switched to the cutting operation at time t2, the condition for setting the (second) target yaw moment is not satisfied (step S36: No in FIG. 7), so the PCM14 sets the target yaw moment to 0. do. However, after the command to set the brake fluid pressure to 0 (in other words, the command to release the brake fluid pressure) is issued, the brake fluid pressure becomes less than the hydraulic pressure (caliper invalid hydraulic pressure) at which the braking force is not actually applied to the wheels. In the meantime, there is a response delay. That is, there is a response delay between the time when the command for ending the application of the braking force to the wheels by the brake device 16 is issued and the time when the application of the braking force by the brake device 16 is actually completed. This is because the brake device 16 has a delay in reducing the brake fluid pressure (decompression delay) due to an orifice or the like for the purpose of reducing pulsation, so that the brake pad cannot be released immediately after the command, and so-called brake residue occurs. be.
Therefore, as shown in the chart (d), when the steering angle becomes 0 at time t2, the braking force of the yaw moment by the braking device 16 is not immediately applied, so that the yaw moment to the vehicle 1 by the second control is not completed. Is not finished. Therefore, even after the steering angle crosses 0, that is, the yaw moment continues to be generated until the time t2'after the steering operation is switched from the turning back operation to the turning operation.

At time t2 when the steering operation is switched to the cutting operation, an additional deceleration for controlling the attitude of the vehicle 1 is set. Here, as shown by the broken line in the chart (e), when the first control for reducing the torque reduction amount determined based on the additional deceleration from the generated torque of the engine 4 is immediately started at time t2, the second control is performed. Until the time t2'when the yaw moment generated by the vehicle becomes 0, the yaw moment generation and the deceleration generation overlap, and the control intervention of the vehicle as a whole may be excessive.

On the other hand, in the present embodiment, while the yaw moment is generated by the second control (step S26: Yes in FIG. 4), the PCM14 corrects the torque reduction amount based on the yaw moment (FIG. 4). Step S28), since the torque reduction amount of the engine 4 is reduced (that is, the generated torque reduction amount of the engine 4 is reduced), the first control is suppressed in the state where the second control is executed, and the entire vehicle is suppressed. The amount of control intervention as is maintained at the same level.
Then, when the yaw moment generated by the second control becomes 0 at time t2'(step S26: No in FIG. 4), the PCM14 does not correct the torque reduction amount and reduces the torque set based on the steering speed. The first control is performed according to the quantity. After that, when the steering speed _{becomes less than the threshold value S 1} (step S23: No in FIG. 4), the first control ends.

As described above, according to the first embodiment of the present invention, when the braking device 16 generates the yaw moment by the control based on the yaw moment set in the target yaw moment setting process, the PCM 14 has the yaw moment. The larger the value, the smaller the amount of decrease in the generated torque of the engine 4 when the steering angle is increased by the cutting operation of the steering wheel 6. As a result, in the state where the second control of applying the yaw moment to the vehicle during the turning back operation is executed, the first control of applying the deceleration to the vehicle during the turning operation is suppressed, and the control intervention is performed for the entire vehicle. It is possible to suppress the excessive state.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. 9 to 11. FIG. 9 is a flowchart of the additional deceleration setting process according to the second embodiment of the present invention, FIG. 10 is a map showing the relationship between the yaw moment reduction speed and the correction gain of the torque reduction amount, and FIG. 11 is the present invention. It is a time chart which showed the time change of the parameter about the vehicle attitude control when the vehicle equipped with the vehicle control device according to the 2nd Embodiment of the invention makes a turn. Since some parts of the second embodiment have the same configuration as that of the first embodiment, detailed description of such parts will be omitted.

Steps S41 to S45 of the additional deceleration setting process according to the second embodiment shown in FIG. 9 are the same as steps S21 to S25 of the additional deceleration setting process according to the first embodiment shown in FIG.

As shown in FIG. 9, after step S45, in step S46, the PCM 14 has a predetermined threshold value I for the rate of decrease in yaw moment generated by the braking device 16 by control based on the yaw moment set in the target yaw moment setting process. _Judge whether it is t or more.
For example, the PCM 14 acquires the hydraulic pressure supplied to the brake device 16 of each wheel from the detection value of the hydraulic pressure sensor 24, and the yaw moment generated by the brake device 16 in the vehicle 1 based on the acquired hydraulic pressure. To estimate. When the rate of decrease in the estimated yaw moment is equal to or greater than the threshold I _t, is determined as the reduction rate of the yaw moment braking device 16 is caused is greater than or equal to the threshold I _t.

As a result, when the rate of decrease of the yaw moment generated by the braking device 16 is _{equal to} or greater than the threshold value It, the process proceeds to step S47, and the PCM14 has the steering angle straddling 0 degrees based on the detection value of the steering angle sensor 8. It is determined whether or not the vehicle has changed (that is, whether or not the steering wheel 6 has been operated so as to straddle the neutral position).

As a result, when the steering angle changes over 0 degrees, the process proceeds to step S48, and the PCM 14 reduces the yaw moment generated in the vehicle 1 by controlling the braking device 16 based on the yaw moment set in the target yaw moment setting process. The torque reduction amount is corrected based on the speed.
Specifically, the PCM 14 corresponds to the yaw moment reduction speed generated by the brake device 16 in the vehicle 1 based on the relationship between the yaw moment reduction speed shown in the map of FIG. 10 and the correction gain of the torque reduction amount. The torque reduction amount is corrected by acquiring a correction gain K ₂ of 1 or more and multiplying the correction gain K ₂ by the torque reduction amount determined in step S45. As the yaw moment reduction speed generated by the brake device 16 in the vehicle 1, the yaw moment reduction speed estimated in step S46 can be used.
As shown in FIG. 10, the range reduction rate is less than the threshold value I _t of the yaw moment correction gain K ₂ is 1, the range reduction rate is not less than the threshold value I _t of the yaw moment, the reduction rate of the yaw moment The larger the value, the larger the correction gain K ₂ is set. That is, when the lowering speed of the yaw moment generated by the brake device 16 is the third value, the torque reduction amount is larger than when the lowering speed of the yaw moment is the fourth value smaller than the third value. It is corrected so as to be.
After step S48, the PCM 14 ends the additional deceleration setting process and returns to the main routine.

Further, in step S41, if not in turning operation of the steering wheel 6, or, in step S43, if the steering speed is less than the threshold value S _1, PCM 14, the additional deceleration setting without configuring additional deceleration Finish the process and return to the main routine. In this case, the torque reduction amount becomes 0.

Moreover, if the yaw moment reduction rate brake device 16 is caused in step S46 is less than the threshold value I _t, or, if the steering angle in step S47 is not changed across the 0 °, PCM 14, the torque reduction amount The addition / deceleration setting process is completed without the correction of, and the process returns to the main routine. In this case, the torque reduction amount becomes the value determined in step S45.

Next, the operation of the vehicle control device according to the first embodiment of the present invention will be described with reference to FIG. In FIG. 11, chart (a) shows the steering angle of the vehicle making a turn, chart (b) shows the steering speed, chart (c) shows the target lateral jerk set based on the steering speed, and chart (d). ) Indicates the yaw moment generated in the vehicle 1 based on the target yaw moment set in the target yaw moment setting process, and the chart (e) shows the torque reduction amount set in the attitude control process.

As shown in the charts (a) to (d) of FIG. 11, the steering angle, steering speed, target lateral jerk, and yaw moment generated in the vehicle 1 are the same as those shown in FIG. 8 in the first embodiment. Imagine a situation that changes to.

Here, while the yaw moment generated by the second control sharply decreases and becomes 0 at time t2', as shown by the broken line in the chart (e), the rise of the torque reduction amount by the first control If the speed is gradual, the increase in deceleration may be insufficient for the decrease in yaw moment, which may give the driver a sense of discomfort as if the control intervention was suddenly reduced for the vehicle as a whole.

On the other hand, in the present embodiment, while the yaw moment decrease rate generated by the second control _{is equal to} or higher than the threshold value It (step S46: Yes in FIG. 9), the PCM 14 torques based on the yaw moment decrease rate. By correcting the reduction amount (step S48 in FIG. 9), the torque reduction amount of the engine 4 is increased (that is, the generated torque reduction amount of the engine 4 is increased), so that the yaw moment generated by the second control is abrupt. When the torque is reduced to the above, the torque reduction amount by the first control is increased, and the control intervention amount of the vehicle as a whole is maintained at the same level.
Then, when the yaw moment generated by the second control becomes 0 at time t2'(step S46: No in FIG. 9), the PCM14 does not correct the torque reduction amount and reduces the torque set based on the steering speed. The first control is performed according to the quantity. After that, when the steering speed _{becomes less than the threshold value S 1} (step S43: No in FIG. 9), the first control ends.

In this second embodiment, when the braking device 16 generates a yaw moment by control based on the yaw moment set in the target yaw moment setting process, the PCM14 determines that the greater the yaw moment decrease rate, the more the steering wheel 6 The amount of decrease in the generated torque of the engine 4 when the steering angle is increased by the cutting operation of the engine 4 is increased. As a result, when the yaw moment generated by the second control suddenly decreases with the end of the switchback operation, the amount of torque reduction by the first control is increased to make the amount of control intervention for the entire vehicle the same. It can be maintained to a certain degree, and it is possible to prevent the driver from feeling uncomfortable as if the control intervention was suddenly reduced for the entire vehicle.

<Modification example>
Finally, a further modification of the embodiment of the present invention will be described.
In the above-described embodiment, an example of executing the attitude control of the vehicle using the steering angle of the vehicle 1 as the steering angle-related value is shown, but the attitude control is executed based on the yaw rate and the lateral acceleration instead of the steering angle. It may be. These steering angles, yaw rates, and lateral accelerations correspond to an example of "steering angle-related values" in the present invention.
Further, in the above-described embodiment, an example of executing the attitude control of the vehicle using the steering speed of the vehicle 1 as the turning state is shown, but the attitude control is executed based on the yaw acceleration and the lateral jerk instead of the steering speed. You may do so. These steering speeds, yaw accelerations, and lateral jerks correspond to an example of the "turning state" in the present invention.

In the above-described embodiment, it has been described that the PCM 14 causes the vehicle 1 to decelerate due to the decrease in the generated torque of the engine 4, but the alternator is rotated to generate power with or instead of the decrease in the generated torque of the engine 4. The braking force of the regenerative brake due to this, the braking force of the engine brake when the accelerator pedal is not depressed by changing the gear ratio of the automatic transmission to the low speed side (downshift, etc.), the clutch 30 inside the automatic transmission 28 The vehicle 1 is decelerated due to a decrease in vehicle driving force due to a decrease in the degree of engagement of the brake 32 and the degree of engagement (more slippage), a rotational resistance of engine accessories driven by the engine 4 such as an air conditioner compressor 34, and the like. It may be generated.

In the above-described embodiment, in the additional deceleration setting process, the PCM 14 acquires the hydraulic pressure supplied to the brake device 16 of each wheel from the detected value of the hydraulic pressure sensor 24, and the brake device is based on the acquired hydraulic pressure. It was explained that 16 estimates the yaw moment generated in the vehicle 1 and corrects the torque reduction amount based on the estimated yaw moment, but the torque reduction amount generated in the vehicle 1 is corrected by a method different from this. You may. For example, the torque reduction amount may be corrected based on the yaw moment command value set in the target yaw moment setting process or the detection value of the yaw rate sensor 12.

1 Vehicle 2 Front wheels 4 Engine 6 Steering wheel 8 Steering angle sensor 10 Vehicle speed sensor 12 Yaw rate sensor 14 PCM
16 Brake device 18 Brake control system 20 Hydraulic pump 22 Valve unit 24 Hydraulic sensor 26 Spark plug 28 Automatic transmission 30 Clutch 32 Brake 34 Air conditioner compressor

Claims (7)

A steering device, a drive source that generates torque for driving the drive wheels, a generated torque control mechanism that controls the generated torque of the drive source, a brake device that can apply different braking forces to the left and right wheels, and a processor. It is a vehicle control device equipped with
The processor
Based on the turning state of the vehicle, a yaw moment opposite to the yaw rate generated in the vehicle is set, and the brake device is controlled so as to generate the set yaw moment in the vehicle.
When the steering angle-related value related to the steering angle of the steering device increases, the generated torque control mechanism is controlled so as to reduce the generated torque of the drive source.
When the braking device generates a yaw moment, the amount of torque reduction generated by the drive source when the steering angle-related value increases is changed based on the yaw moment.
A vehicle control device characterized by the fact that. The processor said that when the yaw moment generated by the braking device is a first value, it is more than when the yaw moment generated by the braking device is a second value smaller than the first value. The vehicle control device according to claim 1, which is configured to reduce the amount of decrease in the generated torque of the drive source when the steering angle-related value increases. In the processor, when the decrease rate of the yaw moment generated by the brake device is a third value, the decrease rate of the yaw moment generated by the brake device is a fourth value smaller than the third value. The vehicle control device according to claim 1 or 2, wherein the amount of decrease in the generated torque of the drive source when the steering angle-related value increases is larger than in a certain case. Any of claims 1 to 3, wherein the processor is configured to control the braking device so that the set yaw moment is generated in the vehicle when the steering angle related value is decreasing. The vehicle control device according to item 1. The vehicle behavior control device according to any one of claims 1 to 4, wherein the turning state of the vehicle is a steering speed acquired based on a detection value of a steering angle sensor that detects a steering angle of the steering device. The turning state of the vehicle is the rate of change of the difference between the actual yaw rate actually occurring in the vehicle and the target yaw rate set based on the detection value of the steering angle sensor that detects the steering angle of the steering device. The vehicle behavior control device according to any one of claims 1 to 5. The processor drives the steering device when the steering device is operated across a neutral position, when the braking device generates a yaw moment, and when the steering angle-related value increases based on the yaw moment. The vehicle control device according to any one of claims 1 to 6, which is configured to change the amount of reduction in the generated torque of the source.

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