JP4862522B2 - Braking force control device - Google Patents

Description

  The present invention relates to a braking force control device that performs deceleration control when a vehicle turns.

Conventionally, as this type of technology, for example, there is one that performs deceleration control so that the vehicle speed is equal to or lower than a target vehicle speed when the vehicle is turning (see, for example, Patent Documents 1 and 2).
In the technique described in Patent Document 1, when the safe vehicle speed is calculated from the motion state and driving operation of the vehicle and the safe vehicle speed is exceeded, the automatic brake system decelerates to a safe vehicle speed or less, and spin, drift Out and rollover are prevented.

Further, in the technique described in Patent Document 2, when it is detected that the amount of operation of the accelerator pedal tends to increase or exceeds the reference value, the deceleration control is interrupted, whereby the control by the deceleration control is performed. Power can be eliminated and acceleration in line with the driver's intention can be realized.
Japanese Patent Laid-Open No. 10-278762 JP 2002-127888 A

However, among the above-described conventional techniques, the one described in Patent Document 1 performs the accelerator operation by decelerating the vehicle to a safe vehicle speed or less even when the driver performs the accelerator operation. However, there was a risk of giving a sense of stalling that it did not accelerate.
Moreover, in the thing of patent document 2, when the driver | operator is performing accelerator operation, there existed a possibility that it might become overspeed because deceleration control was interrupted.
The present invention aims to solve the above-mentioned unsolved problems of the prior art, and can accelerate the vehicle by the accelerator operation even during the deceleration control, and decelerates even if the accelerator operation is performed. An object of the present invention is to provide a braking force control device capable of continuing control.

In order to solve the above-described problems, a braking force control device according to the present invention is a braking force control device that performs deceleration control when a vehicle turns, and includes an accelerator operation detection unit that detects an accelerator operation of a driver, and the accelerator operation. Based on the driver's accelerator operation detected by the detecting means, the acceleration intention realizing drive torque calculation for calculating the acceleration intention realizing drive torque for realizing the driver's acceleration intention to accelerate the vehicle by the accelerator operation is calculated. A braking torque calculating means for calculating a braking torque to be generated by the deceleration control, and a braking torque calculated by the braking torque calculating means from an acceleration intention realizing driving torque calculated by the acceleration intention realizing driving torque calculating means. A driving torque fluctuation means for increasing or decreasing the driving torque generated by the vehicle based on a subtraction result obtained by subtracting the torque; and an accelerator An accelerator sensitive brake gain setting means for setting an accelerator sensitive brake gain that decreases when the operation amount is equal to or less than a predetermined value and decreases when the operation amount is greater than or equal to a predetermined value; and the braking torque A target brake fluid pressure setting means for setting a target brake fluid pressure based on a value obtained by multiplying the accelerator-sensitive brake gain by a braking force output means for generating a braking force on the vehicle according to the set target brake fluid pressure The acceleration intention realization drive torque calculation means calculates a driver request drive torque that calculates a driver request drive torque to be generated by the driver based on the accelerator operation based on the driver's accelerator operation. Acceleration intention realization drive torque smaller than 1 to the driver request drive torque calculated by the driver and the driver request drive torque calculation means Multiplied by the gain of Arabic, characterized in that it comprises a gain multiplier means for calculating the acceleration intention realizing driving torque.

  Therefore, the braking force control apparatus according to the present invention calculates the acceleration intention realization driving torque for realizing the driver's acceleration intention to accelerate the vehicle by the accelerator operation at the time of turning of the vehicle, and performs the deceleration control. Since the braking torque to be generated is calculated, and the driving torque generated by the vehicle is changed based on the subtraction result obtained by subtracting the braking torque from the acceleration intention realizing driving torque. When the operation is performed, the acceleration intention realization driving torque greatly fluctuates according to the accelerator operation, and the fluctuation amount of the driving torque generated by the vehicle also increases, and the vehicle can be accelerated even during the deceleration control. Moreover, since the deceleration control is not interrupted, the deceleration control can be continued.

Hereinafter, an embodiment of a braking force control apparatus of the present invention will be described with reference to the drawings.
<Configuration of braking force control device>
FIG. 1 is a configuration diagram showing a schematic configuration of the braking force control apparatus of the present embodiment. As shown in FIG. 1, the braking force control device includes a vehicle speed sensor 1, a yaw rate sensor 2, a steering angle sensor 3, an accelerator sensor 4, a controller 5, an engine throttle control unit 6, and a brake control unit 7. .
The vehicle speed sensor 1 detects each wheel speed of the vehicle and outputs the detection result to the controller 5.
The yaw rate sensor 2 detects the yaw rate of the vehicle and outputs the detection result to the controller 5.
The steering angle sensor 3 detects the steering angle by the driver and outputs the detection result to the controller 5.

The accelerator sensor 4 detects the amount of depression of the accelerator pedal 8 by the driver (accelerator operation amount) and outputs the detection result to the controller 5.
The controller 5 executes a deceleration control process (described later) every time a predetermined time elapses, and performs deceleration control during turning of the vehicle based on outputs from the vehicle speed sensor 1, the yaw rate sensor 2, the steering angle sensor 3, and the accelerator sensor 4. The engine throttle control unit 6 and the brake control unit 7 are controlled so that

Further, when the accelerator operation is performed during the deceleration control, the controller 5 controls the engine throttle control unit 6 and the brake control unit 7 so that the generated torque is increased by the drive torque corresponding to the accelerator operation.
The engine throttle control unit 6 controls the throttle of the engine according to a command from the controller 5.
The brake control unit 7 controls the brake of each wheel in accordance with a command from the controller 5.

<Operation of braking force control device>
Next, the deceleration control process executed by the controller 5 will be described based on the flowchart of FIG. This deceleration control process is executed every time a predetermined time (for example, 10 msec.) Elapses. First, in step S21, the vehicle speed V detected by the vehicle speed sensor 1 and the steering angle sensor 3 are detected. A target yaw rate calculation process (described later) for calculating the target yaw rate φ ^* based on the steered steering angle str is executed.

Next, the process proceeds to step S22, and a target vehicle speed calculation process (described later) for calculating the target vehicle speed V ^* based on the target yaw rate φ ^* calculated in step S21 is executed.
Next, the process proceeds to step S23, and target deceleration calculation processing (described later) for calculating the target deceleration Xg ^* based on the target vehicle speed V ^* calculated in step S22 and the vehicle speed V detected by the vehicle speed sensor 1 is performed. Execute.

  Next, the process proceeds to step S24, and based on the accelerator operation amount detected by the accelerator sensor 4, the driver is trying to generate the drive torque (driver requested torque) that is to be generated by the control map indicating the relationship between the accelerator operation amount and the engine torque. etrq-bs) is set and the driver's required torque etrq-bs is multiplied by a gain α (<1, constant) to realize the driver's intention to accelerate the vehicle by depressing the accelerator pedal 8 A driver acceleration intention request torque calculation process (described later) for calculating a drive torque (acceleration intention request torque etrq-drv) is executed.

Next, the process proceeds to step S25, and an overspeed suppression torque calculation process (described later) for calculating the overspeed suppression torque etrq-xg by multiplying the target deceleration Xg ^* calculated in step S23 by a coefficient K is executed.
Next, the process proceeds to step S26, where the target brake hydraulic pressure Pmc is calculated based on the target deceleration Xg ^* calculated in step S23, and the braking force output process for controlling the brake control unit 7 based on the calculation result. (To be described later).
Next, the process proceeds to step S27, where the target engine torque is calculated based on the target deceleration Xg ^* calculated in step S23, and the engine torque output process for controlling the engine throttle control unit 6 based on the calculation result ( After executing (to be described later), this calculation process is terminated.

Target Yaw Rate Calculation Processing Next, the target yaw rate processing in step S21 will be described based on the block diagram of FIG. In the target yaw rate calculation process, first, the yaw rate estimation unit 31 calculates the yaw rate estimated value φest based on the vehicle speed V detected by the vehicle speed sensor 1 and the steering angle str detected by the rudder angle sensor 3. Next, in the select high unit 32, a larger value is set as the target yaw rate φ ^* between the absolute value of the yaw rate estimated value φest and the absolute value of the yaw rate φ detected by the yaw rate sensor 2, and then this calculation process is performed. finish.
That is, when the absolute value of the yaw rate φ is larger than the absolute value of the yaw rate estimated value φest, the absolute value of the yaw rate φ is set to the target yaw rate φ ^* so that the steering angle str is sufficiently small, such as during slow spin. Regardless of this, when the yaw rate φ increases, the deceleration control corresponding to the yaw rate φ can be executed, and the overspeed can be suppressed.

-Target vehicle speed calculation process Next, the target vehicle speed calculation process of the said step S22 is demonstrated based on the flowchart of FIG. In the target vehicle speed calculation process, first, in step S41, the target yaw rate φ ^* calculated in step S21 is acquired.
In step S42, the reference lateral acceleration limit value Ygc (for example, 0.45 g) is set as the lateral acceleration limit value Yg ^* .
Next, the process proceeds to step S43, and it is determined whether or not the target yaw rate φ ^* acquired in step S41 is equal to or greater than a predetermined value (a sufficiently small positive value). If the value is equal to or greater than the predetermined value (YES), the process proceeds to step S44. If the value is smaller than the predetermined value (NO), the process proceeds to step S45.

In step S44, the result of division obtained by dividing the lateral acceleration limit value Yg ^* set in step S42 by the target yaw rate φ ^* acquired in step S41 is set as the target vehicle speed V ^*, and then this calculation process is terminated.
On the other hand, in step S45, the maximum target vehicle speed VMAX (sufficiently high vehicle speed) set in advance is set as the target vehicle speed V ^*, and then this calculation process is terminated.
That is, since the target yaw rate φ ^* is a sufficiently small value, it can be determined that the driver is not steering (not driving on a curved road), so the target vehicle speed V ^* is set to a large value and automatically set. The brake force is prevented from being generated.

-Target deceleration calculation process Next, the target deceleration setting process of the said step S23 is demonstrated based on the flowchart of FIG. In the target deceleration setting process, first, in step S51, the target vehicle speed V ^* calculated in step S22, the vehicle speed V detected by the vehicle speed sensor 1, and the deceleration gain Δt (preset value) are used. get.
Next, the process proceeds to step S52, where the target deceleration Xg ^* is calculated according to the following equation (1) based on the target vehicle speed V ^* , the vehicle speed V and the deceleration gain Δt acquired in step S51. The process ends.
Xg ^* = (V−V ^* ) / Δt (1)

Driver acceleration intention request torque calculation processing Next, the driver acceleration intention request torque calculation processing in step S24 will be described with reference to the flowchart of FIG. In this driver acceleration intention request torque calculation process, first, in step S61, based on the accelerator operation amount detected by the accelerator sensor 4, the driver will generate the control map indicating the relationship between the accelerator operation amount and the engine torque. Drive torque (driver required torque etrq-bs) is set.
Next, the process proceeds to step S62, where the driver's torque to accelerate the vehicle by depressing the accelerator pedal 8 by multiplying the driver request torque etrq-bs set in step S61 by the gain α (<1). After calculating the drive torque (acceleration intention request torque etrq-drv) for realizing the acceleration intention, the calculation process is terminated.

Overspeed suppression torque calculation processing Next, the overspeed suppression torque calculation processing in step S25 will be described with reference to the flowchart of FIG. In this overspeed suppression torque calculation process, first, in step S71, the target deceleration Xg ^* calculated in step S23 is acquired.
Next, the process proceeds to step S72, where the overspeed suppression torque etrq-xg is calculated by multiplying the target deceleration Xg ^* acquired in step S71 by a coefficient K, and then the calculation process is terminated.

-Braking force output process Next, the braking force output process of the said step S26 is demonstrated based on the flowchart of FIG. In this braking force output process, first, in step S81, the target deceleration Xg ^* calculated in step S23 is acquired.
Next, the process proceeds to step S82, where it is determined whether or not the target deceleration Xg ^* acquired in step S81 is greater than zero. If it is greater than 0 (YES), the process proceeds to step S83, and if it is 0 or less (NO), the process proceeds to step S85.
In step S83, the vehicle deceleration device operation flag Flag indicating whether or not to automatically generate braking force is set to the ON state, and then the process proceeds to step S84.

The vehicle deceleration device operation flag Flag is set to the ON state when the braking force is automatically generated, and is set to the OFF state when the braking force is not automatically generated.
In step S84, the target brake fluid pressure Pmc is calculated based on the target deceleration calculated in step S23, and a command for controlling the brake according to the target brake fluid pressure Pmc is output to the brake control unit 7. After executing a power increase side command calculation process (described later), this calculation process is terminated.

On the other hand, in step S85, a braking force reduction command calculation process (described later) for outputting a command for gradually decreasing the target brake hydraulic pressure Pmc to the brake control unit 7 is executed, and then the calculation process is terminated.
Next, the braking force increase side command calculation processing in step S84 will be described based on the flowchart of FIG. In step S91, the braking force increasing side command calculating process first executes an accelerator sensitive brake gain calculating process (described later) for calculating an accelerator sensitive brake gain kac. Next, the target deceleration Xg ^* calculated in step S23, the braking force increase gradient limit value brk-up (a preset value), the braking force decrease gradient limit value brk-dn (a preset value) ) And the driver brake braking force brks.

Next, the process proceeds to step S92, and the target brake hydraulic pressure filter Pmc0 is calculated by multiplying the multiplication value of the target deceleration Xg ^* and the accelerator sensitive brake gain kac acquired in step S91 by the conversion coefficient Kxg.
Next, the process proceeds to step S93, and the amount of change ΔPmc is obtained by subtracting the target brake fluid pressure Pmc calculated when the deceleration control process was executed last time from the target brake fluid pressure filter Pmc0 calculated in step S92. calculate.

  Next, the process proceeds to step S94, and it is determined whether or not the change amount ΔPmc calculated in step S93 is larger than the braking force increase gradient limit value brk-up acquired in step S91. If it is larger than the braking force increase gradient limit value brk-up (YES), the process proceeds to step S95. If it is equal to or less than the braking force increase gradient limit value brk-up (NO), the process proceeds to step S96.

In step S95, the addition result obtained by adding the braking force increase gradient limit value brk-up acquired in step S91 to the target brake hydraulic pressure Pmc calculated when the deceleration control process was executed last time is used as a new target. After the brake fluid pressure Pmc is set, the process proceeds to step S99.
That is, the amount of change (change speed) per time of the target brake fluid pressure Pmc is limited to the braking force increase gradient limit value brk-up or less, and the braking force is applied without generating a rapid deceleration. The overspeed can be suppressed without giving the driver a sense of incongruity.

  On the other hand, in step S96, whether or not the change amount ΔPmc calculated in step S93 is smaller than the sign inversion value (-brk-dn) of the braking force decrease gradient limit value brk-dn acquired in step S91. Determine. If the value is smaller than the sign inversion value (-brk-dn) (YES), the process proceeds to step S97. If the value is greater than the sign inversion value (-brk-dn) (NO), the process proceeds to step S98.

In step S97, the subtraction result obtained by subtracting the braking force increase gradient limit value brk-up acquired in step S91 from the target brake hydraulic pressure Pmc calculated when the deceleration control process was executed last time is used as a new target. After the brake fluid pressure Pmc is set, the process proceeds to step S99.
On the other hand, in step S98, the addition result obtained by adding the amount of change ΔPmc calculated in step S93 to the target brake hydraulic pressure Pmc calculated when the deceleration control process was executed last time is used as a new target brake hydraulic pressure Pmc. Then, the process proceeds to step S99.

  In step S99, the larger one of the target brake hydraulic pressure Pmc set in step S95, S97 or S98 and the driver brake braking force brks-bs acquired in step S91 is set as a new target brake hydraulic pressure Pmc. Then, after outputting a command to control the brake in accordance with the target brake fluid pressure Pmc to the brake control unit 7, the calculation process is terminated.

Next, the accelerator-sensitive brake gain calculation process of step S91 will be described based on the flowchart of FIG. In this accelerator sensitive brake gain calculation process, first, in step S101, the accelerator operation amount Acc detected by the accelerator sensor 4 is acquired.
Next, the process proceeds to step S102, where it is determined whether or not the accelerator operation amount Acc acquired in step S101 is greater than 10%. If it is greater than 10% (YES), the process proceeds to step S103, and if it is 10% or less (NO), the process proceeds to step S104.

In step S103, the accelerator sensitive brake gain kac is set to 0, and then the calculation process is terminated.
On the other hand, in step S104, the accelerator sensitive brake gain kac is calculated according to the following equation (2) based on the accelerator operation amount Acc acquired in step S101, and then the calculation process is terminated.
kac = 50− (Acc−5) × 10 (2)
That is, as shown in FIG. 11, a larger value is calculated as the accelerator sensitive brake gain kac as the accelerator operation amount Acc is smaller.
Next, the braking force reduction command calculation processing in step S85 will be described based on the flowchart of FIG. In this braking force reduction command calculation processing, first, in step S121, the braking force reduction gradient limit value brk-dn and the driver brake control force brk-bs are acquired.

Next, the process proceeds to step S122, and it is determined whether or not the vehicle deceleration device operation flag Flag is in the ON state. If it is in the ON state (YES), the process proceeds to step S123. If it is in the OFF state (NO), the process proceeds to step S127.
In step S123, a new target brake fluid pressure is obtained by subtracting the braking force decrease gradient limit value brk-dn acquired in step S121 from the target brake fluid pressure Pmc calculated when the deceleration control process was executed last time. Pmc.

Next, the process proceeds to step S124, and it is determined whether or not the target brake pressure Pmc calculated in step S123 is smaller than zero. If it is smaller than 0 (YES), the process proceeds to step S125, and if it is 0 or more (NO), the process proceeds to step S126.
In step S125, the target brake fluid pressure Pmc calculated in step S123 is set to 0, and then the process proceeds to step S126.

In the step S126, the target brake pressure Pmc set in the step S123 (the target brake pressure Pmc set in the step S125 when the step S125 is passed) and the driver brake control force brk acquired in the step S121. The larger value of -bs is set as a new target brake fluid pressure Pmc, a command for controlling the brake in accordance with the target brake fluid pressure Pmc is output to the brake control unit 7, and this calculation process is terminated.
On the other hand, in step S127, the driver brake braking force brk-bs acquired in step S121 is set as the target brake fluid pressure Pmc, and a command for controlling the brake according to the target brake fluid pressure Pmc is output to the brake control unit 7. Then, this calculation process is terminated.

-Engine torque output process Next, the engine torque output process of the said step S27 is demonstrated based on the flowchart of FIG. In the engine torque output process, first, a target engine torque raw value calculation process (described later) for calculating a target engine torque raw value etrq0 is executed in step S131. Next, the engine ascending gradient limit value etrq-up (a preset value), the engine decreasing gradient limit value etrq-dn (a preset value), and the driver request torque etrq-bs set in step S61 To get.

Next, the process proceeds to step S132, and it is determined whether or not the vehicle deceleration device operation flag Flag is in an ON state. If it is in the ON state (YES), the process proceeds to step S133, and if it is in the OFF state (NO), the process proceeds to step S144.
In step S133, a subtraction result obtained by subtracting the target engine torque etrq (previous torque etrq-z1) calculated when the deceleration control process was previously executed from the target engine torque raw value etrq0 calculated in step S131. Is the amount of change Δetrq.

  Next, the process proceeds to step S134, and it is determined whether or not the change amount Δetrq calculated in step S133 is larger than the engine ascending gradient limit value etrq-up acquired in step S131. If it is larger than the engine upward gradient limit value etrq-up (YES), the routine proceeds to step S135, and if it is equal to or smaller than the engine upward gradient limit value etrq-up (NO), the routine proceeds to step S136.

In other words, the amount of change in the target engine torque etrq is limited to the engine ascending gradient limit value etrq-up or less, so that sudden acceleration is not generated and engine torque is generated so that the driver does not feel uncomfortable. A target engine torque etrq is calculated.
In step S135, the addition result obtained by adding the engine climb gradient limit value etrq-up acquired in step S131 to the previous torque etrq-z1 is set as the target engine torque etrq, and the process proceeds to step S139.

  On the other hand, in step S136, it is determined whether or not Δetrq calculated in step S133 is smaller than the sign opposite value (-etrq-up) of the engine ascending gradient limit value etrq-up acquired in step S131. If it is smaller than (-etrq-up) (YES), the process proceeds to step S137, and if it is equal to or greater than (-etrq-up) (NO), the process proceeds to step S138.

In step S137, the subtraction result obtained by subtracting the engine decrease gradient limit value etrq-dn acquired in step S131 from the previous torque etrq-z1 is set as the target engine torque etrq, and then the process proceeds to step S139.
On the other hand, in step S138, the target engine torque raw value enrq0 calculated in step S131 is set as the target engine torque etrq, and then the process proceeds to step S139.

  In step S139, it is determined whether or not the target engine torque etrq set in step S135, S137, or S138 is greater than or equal to the driver request torque etrq-bs acquired in step S131. If it is equal to or greater than the driver request torque etrq-bs (YES), the process proceeds to step S140. If it is smaller than the driver request torque etrq-bs (NO), the process proceeds to step S143.

In step S140, the driver request torque etrq-bs acquired in step S131 is set as a new target engine torque etrq.
Next, the process proceeds to step S141, and it is determined whether or not the target brake fluid pressure Pmc is equal to or less than brk-bs. If it is equal to or less than brk-bs (YES), the process proceeds to step S142. If greater than brk-bs (NO), the process proceeds to step S143.

In step S142, the vehicle deceleration device operation flag Flag is set to the OFF state, and then the process proceeds to step S143.
In step S143, first, the target engine torque etrq set in step S135, S137 or S138 is set as the previous torque etrq-z1. Next, the command (the previous torque etrq-z1 is currently generated by the vehicle) that changes the drive torque generated by the vehicle (the drive torque generated by the drive wheels 9) according to the previous torque etrq-z1 The command is added to the drive torque) to the engine torque control unit 6 and the calculation process is terminated.

  On the other hand, in step S144, first, the driver request torque etrq-bs acquired in step S131 is set as the target engine torque etrq and the previous torque etrq-z1. Next, the command (the previous torque etrq-z1 is currently generated by the vehicle) that changes the drive torque generated by the vehicle (the drive torque generated by the drive wheels 9) according to the previous torque etrq-z1 The command to be added to the drive torque is output to the engine torque control unit 6, and then this calculation process is terminated.

  Next, the target engine torque raw value calculation process in step S131 will be described based on the flowchart of FIG. In the target engine torque raw value calculation process, first, in step S151, the driver acceleration will request torque etrq-drv calculated in step S24, the overspeed suppression torque etrq-xg calculated in step S25, and the driver request Get torque etrq-bs.

Next, the process proceeds to step S152, and the target engine torque raw value is obtained by subtracting the overspeed suppression torque etrq-xg acquired in step S151 from the driver acceleration will request torque etrq-drv acquired in step S151. Let etrq0.
That is, when the driver depresses the accelerator pedal 8, the driver acceleration intention request torque etrq-drv increases and the target engine torque raw value etrq0 can also increase.

Next, the process proceeds to step S153, and it is determined whether or not the target engine torque raw value etrq0 calculated in step S152 is larger than the driver request torque etrq-bs acquired in step S151. If it is larger than the driver request torque etrq-bs (YES), the process proceeds to step S154. If it is equal to or less than the driver request torque etrq-bs (NO), this calculation process is terminated.
In step S154, the driver request torque etrq-bs acquired in step S151 is set as the target engine torque raw value etrq0, and the calculation process is terminated.

<Specific operation of braking force control device>
Next, the operation of the braking force control apparatus of the present embodiment will be described based on specific conditions.
First, it is assumed that the deceleration control process is executed by the controller 5 when the accelerator pedal 8 is depressed to accelerate while turning. Then, as shown in FIG. 2, first, in step S21, target yaw rate calculation processing is executed.
When the target yaw rate calculation process is executed, as shown in FIG. 3, first, the yaw rate estimation unit 31 based on the vehicle speed V detected by the vehicle speed sensor 1 and the steering angle str detected by the steering angle sensor 3. The yaw rate estimated value φest is calculated, and the select high unit 32 sets a larger value between the absolute value of the yaw rate estimated value φest and the absolute value of the yaw rate φ detected by the yaw rate sensor 2 as the target yaw rate φ ^*. The computation process ends.

When the target yaw rate calculation process ends, the target vehicle speed calculation process is executed in step S22 of the deceleration control process.
When the target vehicle speed calculation process is executed, as shown in FIG. 4, first, in step S41, the calculated target yaw rate φ ^* is acquired, and in step S42, the reference lateral acceleration limit value Ygc is set. In step S42, an accelerator-sensitive lateral acceleration correction value Yga is set, and an addition result obtained by adding the set reference lateral acceleration limit value Ygc to the accelerator-sensitive lateral acceleration correction value Yga is set as a lateral acceleration limit value Yg ^* .

Next, the determination in step S43 is “YES”, and after the division result obtained by dividing the calculated lateral acceleration limit value Yg ^* by the acquired target yaw rate φ ^* is set to the target vehicle speed V ^* in step S44. This calculation process is terminated.
When the target vehicle speed calculation process ends, the target deceleration calculation process is executed in step S23 of the deceleration control process.

When the target deceleration calculation process is executed, as shown in FIG. 5, first, in step S51, the calculated target vehicle speed V ^* , the vehicle speed V detected by the vehicle speed sensor 1, and the deceleration gain Δt are acquired. In step S52, the target deceleration Xg ^* is calculated based on the target vehicle speed V ^* , the vehicle speed V, and the deceleration gain Δt, and this calculation process is terminated.
When the target deceleration calculation process is completed, a driver acceleration intention request torque calculation process is executed in step S24 of the deceleration control process.

  When the driver acceleration intention request torque calculation process is executed, as shown in FIG. 6, first, based on the accelerator operation amount detected by the accelerator sensor 4 in step S61, the depression amount of the accelerator pedal 8 and the engine torque The driver request torque etrq-bs is set to a large value in accordance with the control map showing the relationship (FIG. 15 (a), time t1). In step S62, the driver request torque etrq-bs is multiplied by the gain α (<1). Then, after the driver acceleration intention request torque etrq-drv is set to a large value (FIG. 15B, time t1), this calculation process is terminated.

That is, it is estimated that the driving torque for realizing the driver's intention to accelerate the vehicle by depressing the accelerator pedal 8 is a large value.
When the driver acceleration intention request torque calculation process is completed, an overspeed suppression torque calculation process is executed in step S25 of the deceleration control process.
When the overspeed suppression torque calculation process is executed, as shown in FIG. 7, first, in step S71, the calculated target deceleration Xg ^* is acquired, and in step S72, the target deceleration Xg ^* is obtained. After the coefficient K is multiplied and the overspeed suppression torque etrq-xg (braking torque by deceleration control) is calculated (FIG. 15 (c), time t1), this calculation process is terminated.

When the overspeed suppression torque calculation process is completed, a braking force output process is executed in step S26 of the deceleration control process.
When the braking force output process is executed, as shown in FIG. 8, first, in step S81, the calculated target deceleration Xg ^* is acquired, the determination in step S82 becomes "YES", and in step S83. Then, after the vehicle deceleration device operation flag Flag is turned on, the braking force increase side command calculation process is executed in step S84.

When the braking force increase command calculation process is executed, as shown in FIG. 9, first, in step S91, an accelerator sensitive brake gain calculation process is executed (see FIG. 10), and the accelerator operation amount Acc is 10% or more. , The accelerator sensitive brake gain kac is set to 0, and the calculated target deceleration Xg ^* , braking force increase gradient limit value brk-up, braking force decrease gradient limit value brk-dn, and driver brake control are calculated. Power brks are acquired.

Further, in step S92, the target brake fluid pressure filter Pmc0 is set to 0 by multiplying the obtained multiplication value of the target deceleration Xg ^* and the accelerator sensitive brake gain kac by the conversion coefficient Kxg, and in step S93, the target brake fluid The target brake fluid pressure Pmc (value 0) calculated when this calculation process was executed last time is subtracted from the pressure filter Pmc0 (value 0) to calculate the change amount ΔPmc (value 0). Further, the determinations in steps S94 and S98 are “NO”, and in step S98, the calculated change amount ΔPmc (value) is set to the target brake hydraulic pressure Pmc (value 0) calculated when this calculation process was executed last time. 0) is added as the new target brake fluid pressure Pmc (value 0), and in step S99, a command for controlling the brake according to the target brake fluid pressure Pmc (command for not generating braking force) is brake control. After being output to the unit 7, this calculation process is terminated.

When the braking force output process ends, the engine torque output process is executed in step S27 of the deceleration control process.
When the engine torque output process is executed, as shown in FIG. 13, first, a target engine torque raw value calculation process is executed in step S131.
When the target engine torque raw value calculation process is executed, as shown in FIG. 14, first, in step S151, the calculated driver acceleration will request torque etrq-drv, overspeed suppression torque etrq-xg, and driver request are calculated. Torque etrq-bs is acquired, and in step S152, a subtraction result obtained by subtracting the overspeed suppression torque etrq-xg from the driver acceleration will request torque etrq-drv is set as a target engine torque raw value etrq0 (FIG. 15 (d)). ), Time t1).

In other words, the subtraction result obtained by subtracting the braking torque by the deceleration control from the driving torque for realizing the driver's intention to accelerate is set as the target engine torque raw value etrq0.
If the target engine torque raw value etrq0 is equal to or less than the acquired driver request torque etrq-bs, the determination in step S153 becomes “NO”, and this calculation process ends.

  When the target engine torque raw value calculation process is completed, in step S131 of the engine torque output process, the engine ascending gradient limit value etrq-up, the engine decreasing gradient limit value etrq-dn, and the set driver request torque etrq-bs are acquired. Is done. In addition, the determination in step S132 is “YES”, and in step S133, the subtraction result obtained by subtracting the previous torque etrq-z1 from the calculated target engine torque raw value etrq0 is set as the change amount Δetrq, and the change amount Δetrq is If the obtained engine ascending slope limit value etrq-up is less than or equal to the engine decreasing slope limit value etrq-dn and the sign inversion value (-etrq-dn) is exceeded, the determinations in steps S134 and S136 are “NO”. In step S138, the calculated target engine torque raw value enrq0 is set as the target engine torque etrq.

  If the target engine torque etrq is smaller than the acquired driver request torque etrq-bs, the determination in step S139 is “NO”, and in step S143, the set target engine torque etrq is the previous torque etrq− After a command to control the drive torque according to the previous torque etrq-z1 is output to the engine torque control unit 6, this calculation process is terminated.

The brake control unit 7 sets the braking force to 0 according to the command output from the controller 5, and the engine throttle control unit 6 generates a large torque according to the command output from the controller 5.
Further, it is assumed that after the above-described flow is repeatedly executed and the vehicle is accelerated, the deceleration process is executed by the controller 5 when the accelerator pedal 8 is loosened because the necessity of acceleration is lost. Then, as shown in FIG. 2, a driver acceleration intention request torque calculation process is executed in step S24 through steps S21, S22, and S23.

  When the driver acceleration intention request torque calculation process is executed, as shown in FIG. 6, the driver request torque etrq-bs is set to a small value based on the accelerator operation amount (small opening) in step S61 (see FIG. 6). 15 (a), time t2), after the driver requested torque etrq-bs is multiplied by the gain α to reduce the driver acceleration intention requested torque etrq-drv to a small value in step S62 (FIG. 15B). At time t2), this calculation process is terminated.

That is, it is estimated that the driving torque for realizing the driver's intention to accelerate the vehicle by depressing the accelerator pedal 8 is a small value.
When the driver acceleration intention request torque calculation processing ends, in step S25 of the deceleration control processing, overspeed suppression torque calculation processing is executed (see FIG. 7), and after overspeed suppression torque etrq-xg is calculated (FIG. 15 ( c) At time t2), the calculation process is terminated.

When the overspeed suppression torque calculation process is completed, a braking force output process is executed in step S26 of the deceleration control process. As shown in FIG. 8, the braking force output process is performed in steps S81, S82, and S83, and in step S84. The ascending command calculation process is executed.
When the braking force increase side command calculation process is executed, as shown in FIG. 9, the accelerator sensitive brake gain calculation process is executed in step S91 (see FIG. 10), and the accelerator operation amount Acc is 10% or more. Then, the accelerator sensitive brake gain kac is set to 0, the target brake hydraulic pressure Pmc is set to 0 again through the steps S92 to S98, and the brake is controlled according to the target brake hydraulic pressure Pmc in the step S99. After the command (command not to generate the braking force) is output to the brake control unit 7, the calculation process is terminated.

When the braking force output process ends, the engine torque output process is executed in step S27 of the deceleration control process.
When the engine torque output process is executed, as shown in FIG. 13, in step S131, a target engine torque raw value calculation process is executed (see FIG. 14), and the set driver acceleration will request torque etrq-drv is set. The subtraction result obtained by subtracting the set overspeed suppression torque etrq-xg from (small value) (a value smaller than the target engine torque raw value etrq0 when the accelerator pedal 8 is depressed) is set as the target engine torque raw value etrq0. (FIG. 15 (d), time t2).

When the target engine torque raw value calculation process is completed, the target engine torque raw value enrq0 is set to the target engine torque etrq (previous torque etrq-z1) through steps S132 to S143, and according to the previous torque etrq-z1 A command for controlling the drive torque is output to the engine torque control unit 6 and the calculation process is terminated.
The braking force is set to 0 by the brake control unit 7 according to the command output from the controller 5, and a small torque is generated by the engine throttle control unit 6 according to the command output from the controller 5.

  Furthermore, it is assumed that the deceleration process is executed by the controller 5 when the above flow is repeatedly executed, the vehicle is decelerated, and the driver further loosens the accelerator pedal 8. Then, as shown in FIG. 2, after step S21, S22 and S23, driver acceleration intention request torque calculation processing is executed in step S24 (see FIG. 6), and driver acceleration intention request torque etrq-drv is small. (FIG. 15B, time t3). In step S25, an overspeed suppression torque calculation process is executed (see FIG. 7), and the overspeed suppression torque etrq-xg is calculated (FIG. 15 ( c) At time t3), the calculation process is terminated.

When the overspeed suppression torque calculation process is completed, a braking force output process is executed in step S26 of the deceleration control process. As shown in FIG. 8, the braking force output process is performed in steps S81, S82, and S83, and in step S84. The ascending command calculation process is executed.
When the braking force increase command calculation process is executed, as shown in FIG. 9, the accelerator sensitive brake gain calculation process is executed in step S91 (see FIG. 10), and the accelerator operation amount Acc is smaller than 10%. Then, the accelerator sensitive brake gain kac is set to a positive value of 50 or less, and the calculated target deceleration Xg ^* , braking force increase gradient limit value brk-up, braking force decrease gradient limit value brk-dn, and driver brake are calculated. The braking force brks is acquired.

In step S92, a target brake hydraulic pressure filter Pmc0 (> 0) is calculated by multiplying the obtained multiplication value of the target deceleration Xg ^* and accelerator sensitive brake gain kac by a conversion coefficient Kxg, and in step S93. Then, the target brake fluid pressure Pmc (value 0) calculated when this calculation process was executed last time is subtracted from the target brake fluid pressure filter Pmc0 (> 0), and the change amount ΔPmc (= Pmc0) is calculated. . If the change amount ΔPmc is equal to or less than the braking force increase gradient limit value brk-up and equal to or greater than the sign opposite value (−brk-up) of the braking force decrease gradient limit value, the determinations in steps S94 and S98 are made. “NO”, and in step S98, the addition result obtained by adding the calculated change amount ΔPmc (= Pmc0) to the target brake fluid pressure Pmc (value 0) calculated when the calculation process was executed last time is obtained. The new target brake fluid pressure Pmc (= Pmc0) is set, and in step S99, a command for controlling the brake in accordance with the target brake fluid pressure Pmc is output to the brake control unit 7, and the calculation process is terminated.

When the braking force output process ends, the engine torque output process is executed in step S27 of the deceleration control process.
When the engine torque output process is executed, as shown in FIG. 13, in step S131, a target engine torque raw value calculation process is executed (see FIG. 14), and the set driver acceleration will request torque etrq-drv is set. A subtraction result obtained by subtracting the set overspeed suppression torque etrq-xg from (small value) (a value smaller than the target engine torque raw value etrq0 so far) is set as a target engine torque raw value etrq0 (FIG. 15 ( d) Time t3).

When the target engine torque raw value calculation process is completed, the target engine torque raw value enrq0 is set to the target engine torque etrq (previous torque etrq-z1) through steps S132 to S143, and according to the previous torque etrq-z1 After a command for controlling the drive torque is output to the engine torque control unit 6, this calculation process is terminated.
Then, a braking force is generated by the brake control unit 7 according to the command output from the controller 5, and a small torque is generated by the engine throttle control unit 6 according to the command output from the controller 5.

  As described above, in the above-described embodiment, the accelerator sensor 4 in FIG. 1 constitutes the accelerator operation detecting means described in the claims. Similarly, the controller 5 in FIG. 1 and step S24 in FIG. The controller 5 in FIG. 1 and steps S21 to S23 and S25 in FIG. 2 constitute braking torque calculating means, and the controller 5 in FIG. 1, step S27 in FIG. 2, and steps S94 to 98 in FIG. 6 constitutes a driver required drive torque calculation means, and step S62 in FIG. 6 constitutes a gain multiplication means.

  (1) As described above, in the braking force control apparatus of the present embodiment, the acceleration intention realizing drive torque (driver acceleration intention request) for realizing the driver's acceleration intention to accelerate the vehicle by the accelerator operation. (Torque etrq-drv) is calculated (step S62), the braking torque (overspeed suppression torque etrq-xg) at which deceleration control is to occur when the vehicle turns is calculated (step S72), and the driver acceleration intention request torque etrq is calculated. The driving torque generated by the vehicle is changed based on the subtraction result (target engine torque raw value etrq0) obtained by subtracting the overspeed suppression torque etrq-xg from -drv (steps S152 and S138). Therefore, when the driver performs an accelerator operation during turning of the vehicle, the driver acceleration intention request torque etrq-drv greatly fluctuates according to the accelerator operation, and the fluctuation amount of the drive torque generated by the vehicle also increases. Even during the deceleration control, the vehicle can be accelerated, and the deceleration control can be continued because the deceleration control is not interrupted.

  (2) Further, based on the driver's accelerator operation, the driver request drive torque (driver request torque etrq-bs) that the driver is going to generate by the accelerator operation is calculated, and the driver request torque etrq-bs Since the driver acceleration intention request torque etrq-drv is calculated by multiplying the gain α smaller than 1 by 1, the driver acceleration intention request torque etrq-drv can be easily calculated.

(3) Further, since the drive torque generated by the vehicle is changed so that the amount of change in the generated drive torque (target engine torque etrq) is less than or equal to the engine ascending gradient limit value etrq-up, Torque fluctuation can be suppressed.
The braking force control device of the present invention is not limited to the contents of the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
In the above-described embodiment, the example in which the coefficient α multiplied by the driver request torque etrq-bs is a constant is shown, but the present invention is not limited to this. For example, as shown in FIG. 16, the gain α may be set to a larger value as the accelerator operation amount by the driver is larger. In this case, the driver's intention to accelerate the vehicle is determined. Can be reflected.

  Further, for example, a lateral acceleration detection sensor for detecting the lateral acceleration of the vehicle may be provided, and as shown in FIG. 17, the gain α may be set to a larger value as the lateral acceleration is smaller. As the lateral acceleration is smaller, the driver acceleration intention request torque etrq-drv becomes larger, so the driver's intention to accelerate the vehicle can be reflected in a situation where the lateral force of the driving wheel can be obtained sufficiently, and the lateral acceleration Since the driver acceleration intention request torque etrq-drv becomes smaller as the value increases, the driver's intention to accelerate the vehicle can be reflected while suppressing the occurrence of slip.

Further, for example, a road surface μ detection sensor for detecting the road surface μ of the road surface on which the vehicle is traveling is provided. As shown in FIG. 18, the gain α may be set to a smaller value as the road surface μ is lower. Thus, it is possible to reflect the driver's intention to accelerate the vehicle while suppressing the occurrence of slip.
Further, although an example in which the braking force increase gradient limit value brk-up is a constant has been shown, the present invention is not limited to this. For example, the braking force increase gradient limit value brk-up may be set according to the traveling state (accelerator operation amount, lateral G, road surface μ), and in that case, an appropriate torque according to the traveling state is set. Variations can be obtained.

It is a block diagram which shows schematic structure of one Embodiment of the braking force control apparatus of this invention. It is a flowchart which shows the flow of deceleration control processing. It is a block diagram which shows a target yaw rate process. It is a flowchart which shows the flow of a target vehicle speed calculation process. It is a flowchart which shows the flow of a target deceleration setting process. It is a flowchart which shows the flow of a driver acceleration intention request | requirement torque calculation process. It is a flowchart which shows the flow of an overspeed suppression torque calculation process. It is a flowchart which shows the flow of a braking force output process. It is a flowchart which shows the flow of a braking force raise side command calculation process. It is a flowchart which shows the flow of an accelerator sensitive brake gain calculation process. 7 is a control map showing a relationship between an accelerator operation amount and an accelerator-sensitive brake gain. It is a flowchart which shows the flow of a braking force reduction command calculation process. It is a flowchart which shows the flow of an engine torque output process. It is a flowchart which shows the flow of a target engine torque raw value calculation process. It is a time chart for demonstrating operation | movement of a braking force control apparatus. It is explanatory drawing for demonstrating the modification of the braking force control apparatus of this invention. It is explanatory drawing for demonstrating the modification of the braking force control apparatus of this invention. It is explanatory drawing for demonstrating the modification of the braking force control apparatus of this invention.

Explanation of symbols

1 is a vehicle speed sensor, 2 is a yaw rate sensor, 3 is a steering angle sensor, 4 is an accelerator sensor, 5 is a controller, 6 is an engine throttle control unit, 7 is a brake control unit, 8 is an accelerator pedal, and 9 is a drive wheel

Claims (6)

A braking force control device that performs deceleration control when a vehicle turns,
Based on the accelerator operation detecting means for detecting the driver's accelerator operation and the driver's accelerator operation detected by the accelerator operation detecting means, the driver's intention to accelerate the vehicle by the accelerator operation is realized. Acceleration intention realization drive torque calculation means for calculating acceleration intention realization drive torque for calculating, braking torque calculation means for calculating braking torque to be generated by the deceleration control, and acceleration intention realization drive torque calculation means Drive torque fluctuation means for increasing or decreasing the drive torque generated by the vehicle based on the subtraction result obtained by subtracting the braking torque calculated by the braking torque calculation means from the acceleration intention realization driving torque, and the accelerator operation amount is When the amount of operation is less than a predetermined value, it decreases as the amount of operation increases. Accelerator sensitive brake gain setting means for setting a sensitive brake gain; target brake fluid pressure setting means for setting a target brake fluid pressure based on a value obtained by multiplying the braking torque by the accelerator sensitive brake gain; and the set target Braking force output means for generating braking force on the vehicle according to the brake fluid pressure ,
The acceleration intention realization drive torque calculating means calculates a driver required drive torque calculating means for calculating a driver required drive torque that the driver is going to generate by the accelerator operation based on the driver's accelerator operation; Gain multiplication means for calculating the acceleration intention realization drive torque by multiplying the driver request drive torque calculated by the driver demand drive torque calculation means by a gain for calculating the acceleration intention realization drive torque smaller than 1. A braking force control device. Accelerator operation amount detection means for detecting the driver's accelerator operation amount,
The driver-requested driving torque calculating means, according to claim 1, characterized in that to increase the gain of as the accelerator operation amount is large the acceleration intention realize driving torque for the calculation of the detected driver by the accelerator operation amount detecting means The braking force control apparatus described in 1. A lateral acceleration detecting means for detecting the lateral acceleration of the vehicle;
The driver-requested driving torque calculation means according to claim 1, characterized in that to increase the gain of the higher lateral acceleration is smaller the acceleration intention realize driving torque computation of the detected vehicle by the lateral acceleration detecting means Braking force control device. Road surface μ detecting means for detecting the road surface μ of the road surface on which the vehicle is running,
The driver-requested driving torque calculation means according to claim 1, characterized in that the smaller value the gain of the detected road surface μ is the lower the said acceleration intention realize driving torque computation by the road surface μ detecting means Braking force control device. The driving torque fluctuations means, claim 1, the rate of change of the driving torque to be generated and wherein varying the drive torque which the vehicle to be equal to or less than the predetermined threshold value has occurred in any one of 4 The braking force control apparatus described. 6. The braking force control apparatus according to claim 5 , wherein the driving torque changing means sets the predetermined threshold according to a running state of the vehicle.

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