JP2023108825A - Braking control device of vehicle - Google Patents

Abstract

To prevent drivability from deteriorating so that wheel locking and hunting of a restoration of locking do not occur.SOLUTION: A braking control device 100 of a vehicle controls the vehicle equipped with a regenerative braking device (a motor generator) 2 that generates regenerative braking force, which comprises: an inertial travelling determination part 101 that determines whether the vehicle is inertially travelling or not; a wheel locking determination part 102 that determines whether a wheel is locked or not; and a control part 103 that suppresses regenerative braking force that is generated by the regenerative braking device 2, after the inertial travelling determination part 101 determines that the vehicle is inertially travelling and the wheel locking determination part 102 determines that the wheel is locked, until the inertial travelling determination part 101 determines that the vehicle is not inertially travelling and the wheel locking determination part 102 determines that the wheel is not locked.SELECTED DRAWING: Figure 2

Description

The present invention relates to a braking control device for a vehicle.

Regarding a braking control device for a vehicle, Patent Document 1 discloses a technique for quickly eliminating slipping by executing vehicle stability control that adjusts regenerative braking force applied to the front wheels based on an estimated road surface μ value. there is

JP 2021-103917 A

In a vehicle equipped with a regenerative braking device that generates regenerative braking force, the wheels may lock due to the regenerative braking force when the vehicle enters a low μ road during coasting. Inertial running means running in a state in which the driver does not step on the accelerator pedal or the brake pedal.
In the conventional technology disclosed in Patent Document 1, when the wheels are locked during coasting, the wheels are recovered from the locking by suppressing the regenerative braking force.
However, in this case, if the vehicle continues to coast, the wheels may be unlocked and the suppression of the regenerative braking force may be released, resulting in the wheels being locked again. As a result, locking of the wheels and hunting during lock recovery may occur, degrading drivability.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to prevent deterioration of drivability by preventing wheel locking and locking hunting from occurring.

A braking control device for a vehicle according to the present invention is a braking control device for a vehicle that controls a vehicle equipped with a regenerative braking device that generates regenerative braking force, and includes inertia running determination means for determining whether or not the vehicle is coasting. a wheel lock determination means for determining whether or not the wheels are locked; and the inertia running determination means determines that the vehicle is in the course of inertia running, and the wheel lock determination means determines that the wheels are locked. After that, the regenerative braking force generated by the regenerative braking device is suppressed until the inertia running determination means determines that the vehicle is not coasting and the wheel lock determination means determines that the wheels are not locked. and a control means for controlling.

According to the present invention, it is possible to prevent deterioration of drivability by preventing wheel locking and locking hunting from occurring.

1 is a diagram showing a schematic configuration of essential parts of an automobile according to an embodiment; FIG. 1 is a diagram showing a functional configuration of a vehicle braking control device according to an embodiment; FIG. 4 is a flowchart showing processing executed by the vehicle braking control device according to the embodiment; 4 is a time chart showing time-series changes in wheel speed and regenerative braking force during coasting;

A braking control device for a vehicle according to one embodiment of the present invention is a braking control device for a vehicle that controls a vehicle equipped with a regenerative braking device that generates regenerative braking force, and determines whether or not the vehicle is coasting. wheel lock determination means for determining whether or not the wheels are locked; and the inertia running determination means determines that the vehicle is in the course of inertia running, and the wheel lock determination means determines that the wheels are locked. It is generated by the regenerative braking device until it is determined that the inertia running determination means is not performing inertia running and the wheel lock determination means determines that the wheels are not locked. and control means for suppressing regenerative braking force.
As a result, it is possible to prevent the occurrence of locking of the wheels and hunting during unlocking, thereby preventing deterioration of drivability.

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.
[Example 1]
FIG. 1 shows a schematic configuration of main parts of an automobile, which is a vehicle according to the embodiment.
The vehicle according to the embodiment is a hybrid vehicle that includes an engine 1 that is an internal combustion engine and a motor generator 2 that functions as an electric motor and a generator.
The automobile includes a transmission 5 connected to a crankshaft 3 of an engine 1 to drive a driveshaft 4 and drive wheels 6 to which driving force is transmitted via the driveshaft 4 . A wheel speed sensor 7 is installed on the drive shaft 4 . The transmission 5 is an AMT (Automated Manual Transmission), and includes a clutch 8 connected to the crankshaft 3, a transmission 9 to which the output of the clutch 8 is transmitted, and a differential 10 to transmit the output of the transmission 9 to the drive shaft 4. and The clutch 8 is switched between engagement and disengagement by an actuator 11 . Further, the transmission 9 is switched between gear stages by an actuator 12 .

Also, the motor generator 2 is connected to the transmission 5 downstream of the transmission 9 via the power transmission mechanism 13 . An inverter 14 and a battery (not shown) are connected to the motor generator 2 . When the motor generator 2 functions as an electric motor, the driving force output from the motor generator 2 is input to the driving wheels 6 . On the other hand, when the motor-generator 2 functions as a generator, the motor-generator 2 generates power according to the rotation speed of the drive wheels 6 . At this time, a regenerative braking force (regenerative braking torque) can be generated and applied to the drive wheels 6 . Thus, the motor generator 2 constitutes a regenerative braking device that generates regenerative braking force.

The automobile includes an HCU (Hybrid Control Unit) 15 that controls the hybrid system, an ECU (Engine Control Unit) (not shown) that controls the engine 1 , and a TCM (Transmission Control Module) 16 that controls the transmission 5 .
HCU 15 controls motor generator 2 via inverter 14 . Detection information is input to the HCU 15 from the wheel speed sensor 7 and various sensors 17 .
TCM 16 controls transmission 5 . Specifically, the TCM 16 issues an instruction to the actuator 11 to control switching between engagement and disengagement of the clutch 8 . In addition, the TCM 16 issues instructions to the actuator 12 to control switching of the gear stage of the transmission 9 . Detection information is input to the TCM 16 from the wheel speed sensor 7 and various sensors 17 .
As will be described later, the various sensors 17 include an accelerator pedal switch (accelerator pedal sensor), an accelerator opening sensor, a brake pedal switch (brake pedal sensor), a brake stroke sensor, a master pressure sensor, and a G sensor. Include selected.

FIG. 2 shows the functional configuration of the vehicle braking control device 100 according to this embodiment.
A braking control device 100 of a vehicle includes an inertia running determination unit 101 that determines whether the vehicle is coasting, a wheel lock determination unit 102 that determines whether the wheels are locked, and a regenerative braking device. and a control unit 103 that controls the motor generator 2 .

The inertia running determination unit 101 determines whether or not the vehicle is coasting based on the driver's intention to accelerate, the driver's intention to decelerate, and the stopped state of the vehicle. Whether or not the driver intends to accelerate can be determined based on detection information from the accelerator pedal switch or detection information from the accelerator opening sensor. The acceleration intention refers to the acceleration operation by the driver's stepping on the accelerator pedal. Further, whether or not the driver intends to decelerate can be determined based on information detected by the brake pedal switch, information detected by the brake stroke sensor, or information detected by the master pressure sensor. The deceleration intention refers to the deceleration operation by the driver's depression of the brake pedal. Further, the stop state of the vehicle can be determined based on the detection information of the wheel speed sensor 7 or the detection information of the G sensor.

The wheel lock determination unit 102 determines whether or not the wheels are locked based on the information detected by the wheel speed sensor 7 or the information detected by the G sensor.

After the inertia running determination unit 101 determines that the vehicle is coasting and the wheel lock determination unit 102 determines that the wheels are locked, the control unit 103 determines that the inertia running determination unit 101 is not running. The regenerative braking force generated by the motor generator 2 is set to 0 until the wheel lock determination unit 102 determines that the wheels are not locked.

In the first embodiment, the vehicle braking control device 100 is realized by, for example, the HCU 15, but is not limited to this. For example, the function of the control unit 103 is implemented by the HCU 15, but the functions of the inertial running determination unit 101 and the wheel lock determination unit 102 may be implemented by a device other than the HCU 15 (for example, an ECU).

FIG. 3 is a flow chart showing the processing executed by the vehicle braking control device according to the present embodiment.
The flowchart of FIG. 3 is started when the inertia running determination unit 101 determines that the vehicle is running by inertia and the wheel lock determination unit 102 determines that the wheels are locked. For example, when the vehicle enters a low μ road during coasting, the wheels may be locked by the regenerative braking force generated by the motor generator 2 .
At step S1, the control unit 103 sets the regenerative braking force generated by the motor generator 2 to zero.
In step S2, the control unit 103 maintains the processing of step S1 until it is determined by the wheel lock determination unit 102 that the wheels are unlocked. proceed to
In step S3, the control unit 103 maintains the processing of step S1 until the inertia running determination unit 101 determines that the vehicle is not running by inertia.
In step S4, the control unit 103 sets the regenerative braking force generated by the motor generator 2 to the normal regenerative braking force.
As described above, after the inertia running determination unit 101 determines that the vehicle is running by inertia and the wheel lock determination unit 102 determines that the wheels are locked, the inertia running determination unit 101 determines that the vehicle is not running by inertia. The regenerative braking force generated by the motor generator 2 is set to 0 until the wheel lock determination unit 102 determines that the wheels are not locked.

FIG. 4 shows chronological changes in wheel speed and regenerative braking force during coasting.
FIG. 4(b) is a timing chart in the prior art.
If the wheels lock during coasting (t ₁ ), the wheel speed will decrease. At this time, by setting the regenerative braking force generated by the motor generator to 0 (t ₂ ), the wheels are unlocked (t ₃ ), and then the suppression of the regenerative braking force is released (t ₄ ). In this case, since the vehicle continues to coast, there is a risk that the wheels will be locked again by the regenerative braking force generated by the motor generator (t ₅ ). As a result, locking of the wheels and hunting during lock recovery may occur.

FIG. 4(a) is a timing chart in this embodiment.
If the wheels lock during coasting (t ₁ ), the wheel speed will decrease. At this time, by setting the regenerative braking force generated by the motor generator 2 to 0 (t ₂ ), the wheels are unlocked (t ₃ ). After that, the regenerative braking force is maintained at 0 while the inertia running is continued. As a result, it is possible to suppress the locking of the wheels and the occurrence of hunting during unlocking.

In this embodiment, an example in which the regenerative braking force generated by the motor generator 2 is set to 0 has been described, but the regenerative braking force generated by the motor generator 2 may be suppressed. Suppressing the regenerative braking force means making it lower than the normal regenerative braking force, which is lower than the regenerative braking force indicated by the characteristic line 401 in the example of FIG.

As described above, it is possible to prevent deterioration of drivability by preventing wheel locking and locking hunting.
In addition, by suppressing regenerative braking, a decrease in the amount of power generated by the motor generator 2 can be suppressed. Furthermore, since the torque-up control for driving the motor generator 2 to recover the wheel lock can be minimized, power consumption in the motor generator 2 can be suppressed.
It should be noted that wheel locking is not a problem during vehicle acceleration and vehicle stopping, and wheel locking due to brake pedal depression is controlled by a conventional anti-lock braking system (ABS).

[Example 2]
Next, Example 2 will be described. In the second embodiment, a hybrid vehicle as shown in FIG. 1 will be described as an example, and the same reference numerals will be assigned to the same configurations as in the first embodiment, and the description thereof will be omitted. to explain.
In the first embodiment, braking control for the regenerative braking force generated by the motor generator 2 has been described, but it is also possible to perform similar braking control for the braking force (engine braking torque) generated by resistance in the engine 1. is.

In the second embodiment, a braking control device 100 for a vehicle controls a braking force transmission mechanism that transmits the braking force generated by the engine 1 to the wheels, for example the clutch 8 in FIG. That is, in FIG. 2, the regenerative braking device (motor generator) 2 may be replaced with a braking force transmission mechanism. After the inertia running determination unit 101 determines that the vehicle is coasting and the wheel lock determination unit 102 determines that the wheels are locked, the control unit 103 determines that the inertia running determination unit 101 is not running. and the wheel lock determination unit 102 determines that the wheels are not locked, the braking force transmitted by the clutch 8 is suppressed. For example, the clutch 8 is switched to the disengaged state so as not to transmit the braking force.

Although the clutch 8 is controlled as the braking force transmission mechanism in the example, the transmission 9 may be controlled. In this case, the control unit 103 determines that the inertia running determination unit 101 is in the process of coasting and the wheel lock determination unit 102 determines that the wheels are locked. The braking force transmitted by the transmission 9 is suppressed until it is determined that the vehicle is not running and the wheel lock determination unit 102 determines that the wheels are not locked. For example, the transmission 9 is switched to the neutral gear so as not to transmit the braking force.

In the second embodiment, the vehicle braking control device 100 is implemented by, for example, the TCM 16, but is not limited to this. For example, the function of the control unit 103 is implemented by the TCM 16, but the functions of the inertial running determination unit 101 and the wheel lock determination unit 102 may be implemented by a device other than the TCM 16 (for example, an ECU).

As described above, it is possible to prevent deterioration of drivability by preventing wheel locking and locking hunting.
Alternatively, the braking force (engine braking torque) may be suppressed by returning from fuel cut to an idling state. By these methods, it is possible to suppress the wheel lock due to the braking force (engine braking torque), so that the torque-up control for driving the engine 1 to recover the wheel lock is also minimized, so the fuel consumption in the engine 1 is reduced. can be suppressed.

Note that in a hybrid vehicle as shown in FIG. 1, the first embodiment and the second embodiment are combined, that is, both suppressing the regenerative braking force and suppressing the braking force (engine braking torque) are performed. can be
Further, although the first and second embodiments have explained the hybrid vehicle, as is clear from the first embodiment, the present invention can also be applied to an electric vehicle. It can also be applied to engine vehicles.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, each embodiment merely shows a specific example for carrying out the present invention. The technical scope of the present invention is not limited to each example. The present invention can be modified in various ways without departing from its gist, and these are also included in the technical scope of the present invention.
A braking control device for a vehicle to which the present invention is applied is composed of a computer device having, for example, a CPU, a ROM, a RAM, etc. The CPU executes a predetermined program stored in the ROM, for example, so that the functions of each means are controlled. Realized. Further, the braking control device for a vehicle to which the present invention is applied may be configured by cooperation of a plurality of computer devices.

1: Engine, 2: Motor Generator, 5: Transmission, 7: Wheel Speed Sensor, 8: Clutch, 9: Transmission, 15: HCU, 16: TCM, 17: Sensor, 100: Vehicle Braking Control Device, 101: Inertia running determination unit 102: wheel lock determination unit 103: control unit

Claims (5)

A braking control device for a vehicle that controls a vehicle equipped with a regenerative braking device that generates regenerative braking force,
an inertia running determination means for determining whether or not the vehicle is coasting;
wheel lock determination means for determining whether or not the wheels are locked;
After the inertia determining means determines that the vehicle is coasting and the wheel lock determining means determines that the wheels are locked, the inertia determining means determines that the vehicle is not coasting, and and control means for suppressing regenerative braking force generated by said regenerative braking device until said wheel lock determination means determines that the wheels are not locked. The control means determines that the vehicle is not coasting after the inertia determining means determines that the vehicle is coasting and the wheel lock determining means determines that the wheels are locked. 2. The vehicle according to claim 1, wherein the regenerative braking force generated by the regenerative braking device is set to 0 until it is determined that the wheel is not locked by the wheel lock determining means. braking control device. A braking control device for a vehicle that controls a vehicle including an engine that generates braking force by resistance and a braking force transmission mechanism that transmits the braking force generated by the engine to wheels,
wheel lock determination means for determining whether or not the wheels are locked;
an inertia running determination means for determining whether or not the vehicle is coasting;
After the inertia determining means determines that the vehicle is coasting and the wheel lock determining means determines that the wheels are locked, the inertia determining means determines that the vehicle is not coasting, and and a control means for suppressing the braking force transmitted by the braking force transmission mechanism until the wheel lock determination means determines that the wheels are not locked. The control means determines that the vehicle is not coasting after the inertia determining means determines that the vehicle is coasting and the wheel lock determining means determines that the wheels are locked. 4. The vehicle according to claim 3, wherein the braking force is not transmitted by the braking force transmission mechanism until the wheel lock determination means determines that the wheels are not locked. braking control device. 5. The inertial running determining means determines whether or not the vehicle is coasting based on the driver's intention to accelerate, the driver's intention to decelerate, and the stopped state of the vehicle. The braking control device for a vehicle according to any one of claims 1 to 3.

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