JP5333245B2 - Vehicle behavior control device - Google Patents

Description

  The present invention relates to a vehicle behavior control device.

  The minimum turning radius of a vehicle is determined based on the vehicle-specific characteristics such as the wheel base and the maximum turning angle of the wheel. When the vehicle performs a U-turn or parking in a narrow parking lot, a turning radius smaller than the minimum turning radius may be required. In this case, the driver needs to perform a driving operation such as turning over, and the driver is required to perform a complicated driving operation in a vehicle having a long wheelbase such as a minivan having a large minimum turning radius. 2. Description of the Related Art Conventionally, as a device that executes braking control for shortening the turning radius when a vehicle turns, for example, there is one described in Patent Document 1 below.

  In the vehicle braking control device described in Patent Document 1, when the absolute value of the steering angle of the steering wheel is equal to or larger than the steering angle threshold, among the wheels on the inner side in the turning direction of the vehicle, the control brake is set in advance. A braking force is applied to the wheels.

JP 2008-094302 A

  By the way, some vehicles are equipped with an ABS (Antilock Brake System) that executes braking force control based on a speed difference between left and right wheels as a braking control device. This ABS adjusts the braking force of each wheel according to the degree of slip of the other wheel with respect to the reference wheel, and suppresses the lock of the driving wheel. In this case, when this ABS is mounted on the above-described conventional vehicle braking control device, the turning control and the ABS control may interfere with each other.

  In other words, when turning control (turning radius shortening control) is activated while the vehicle is turning, the wheel speed of the rear turning inner wheel is changed to the rear turning due to the addition of braking force to the turning inner wheel of the rear by turning radius reduction control and the turning inner wheel difference. It is much lower than the wheel speed of the outer ring. In the ABS control, the reference wheel becomes a wheel having a high wheel speed, that is, a turning outer wheel (rear turning outer wheel), and the degree of apparent slip between the wheel turning rear wheel and the rear turning inner wheel having a low wheel speed becomes very large. Therefore, even in a situation where the ABS does not operate, that is, in a situation where the wheels are not actually locked, there is a risk that the ABS will operate and the braking force of the rear turning inner wheel may be reduced. Stability is reduced.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle behavior control device that can suppress interference between vehicle turning control and braking force control.

  The vehicle behavior control device of the present invention includes a first control device that performs turning control based on a driving force difference or a braking force difference between left and right wheels, a second control device that performs braking force control based on a speed difference between left and right wheels, And an arbitration device that suppresses braking force control by the second control device when the turning control by the first control device is executed.

  In the vehicle behavior control device, the arbitration device may change the control threshold value in the second control device to a value that makes it difficult to operate the braking force control when the turning control by the first control device is executed. preferable.

  In the vehicle behavior control device, the arbitration device is configured such that the greater the difference in driving force between the left and right wheels in the turn control by the first control device, the harder the braking force control to operate as the control threshold value in the second control device. It is preferable to change to.

  In the vehicle behavior control device, the arbitration device preferably stops the braking force control by the second control device when the turning control by the first control device is executed.

  In addition, the vehicle behavior control device of the present invention includes a first control device that performs turning control based on a driving force difference or a braking force difference between left and right wheels, and a second control device that performs braking force control based on a speed difference between left and right wheels. And an arbitration device that suppresses the turn control by the first control device when an operation condition of the turn control by the second control device is satisfied when the turn control by the first control device is executed. And

  In the vehicle behavior control device, in the turning control by the first control device, the inner turning wheel is set as a reference wheel, and the first control device applies a braking force larger than the other wheels to the reference wheel. It is preferable.

  In the vehicle behavior control device, in the braking force control by the second control device, a wheel having a high wheel speed is set as a reference wheel, and the second control device is given by a speed difference between the reference wheel and another wheel. It is preferable to adjust the braking force to be applied.

  In the vehicle behavior control device, it is preferable that the first control device performs turning control when the vehicle speed is equal to or less than a predetermined vehicle speed set in advance and the steering angle is equal to or greater than a predetermined steering angle set in advance. .

  In the vehicle behavior control device, it is preferable that the first control device determines a driving force difference between left and right wheels according to at least one of an accelerator operation amount and a steering angle.

  Since the vehicle behavior control device according to the present invention suppresses the braking force control by the second control device when the turning control by the first control device is executed, the interference between the turning control and the braking force control can be suppressed. There is an effect that can be done.

  The vehicle behavior control device according to the present invention suppresses the turn control by the first control device when the turning control by the second control device is satisfied when the turn control by the first control device is executed. Therefore, there is an effect that interference between the turning control and the braking force control can be suppressed.

FIG. 1 is a control block diagram showing a vehicle behavior control apparatus according to Embodiment 1 of the present invention. FIG. 2 is an explanatory diagram of turning radius shortening control by the vehicle behavior control device of the first embodiment. FIG. 3 is a flowchart showing the flow of processing by the vehicle behavior control apparatus of the first embodiment. FIG. 4 is a flowchart showing the flow of processing by the vehicle behavior control apparatus according to the second embodiment of the present invention. FIG. 5 is a flowchart showing the flow of processing by the vehicle behavior control apparatus according to the second embodiment of the present invention.

  Hereinafter, an embodiment of a vehicle behavior control device according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment.

Embodiment 1
FIG. 1 is a control block diagram showing a vehicle behavior control apparatus according to Embodiment 1 of the present invention, FIG. 2 is an explanatory diagram of turning radius shortening control by the vehicle behavior control apparatus of Embodiment 1, and FIG. It is a flowchart showing the flow of the process by this vehicle behavior control apparatus.

  In the first embodiment, the vehicle behavior control device of the present invention will be described by being mounted on a vehicle that can drive rear wheels by an engine, a motor, or the like and can apply braking force to four wheels by a brake device. The vehicle behavior control apparatus of the first embodiment has at least an ABS control function and a turning control function (hereinafter referred to as a turning radius shortening control function), and makes it difficult to operate the ABS control during the turning radius shortening control. .

  In the first embodiment, the ABS control function in the vehicle behavior control device can be realized by the second control device of the present invention, the turning control function can be realized by the first control device of the present invention, and the turning radius is shortened. The function of making the ABS control difficult to operate during the control can be realized by the arbitration device of the present invention.

  In the first embodiment, as shown in FIG. 1, the vehicle behavior control device 11 reduces the braking force with respect to the locked wheel in order to suppress the locking of the wheel and efficiently transmit the braking force to the road surface. To do. Further, the vehicle behavior control device 11 shortens the turning radius by applying a braking force to the rear turning inner wheel at the time of turning at a low speed and a large steering angle in order to improve the turning performance at the time of turning. The vehicle behavior control device 11 makes it difficult to operate the ABS control during the turning radius shortening control in order to perform the optimum ABS control even when the turning radius shortening control is being performed.

  The vehicle behavior control device 11 includes an ECU (Electronic Control Unit) 12 as a control device. Further, as sensors for detecting the driving state of the vehicle, there are wheel speed sensors 21, 22, 23, 24, a steering angle sensor 25, an accelerator opening sensor 26, a longitudinal acceleration sensor 27, a lateral acceleration sensor 28, and a yaw rate sensor 29. , Connected to the ECU 12. Further, the vehicle behavior control device 11 has four wheel cylinder actuators 31, 32, 33, 34 as a device for controlling the behavior of the vehicle, that is, controlling the braking force, and is connected to the ECU 12.

  Wheel speed sensors 21, 22, 23, and 24 are provided on the front right wheel FRW, the front left wheel FLW, the rear right wheel RRW, and the rear left wheel RLW, and can detect the rotational speeds of the wheels FRW, FLW, RRW, and RLW. it can. The wheel speed sensors 21, 22, 23, and 24 detect the rotational speeds of the wheels FRW, FLW, RRW, and RLW, and transmit the detected values to the ECU 12 as wheel speed signals.

  The steering angle sensor 25 is provided at a predetermined location in the steering mechanism from the steering wheel to the steered wheel, and can detect the steering angle. This rudder angle sensor 25 detects the rudder angle and transmits the detected value to the ECU 12 as a rudder angle signal.

  The accelerator opening sensor 26 is provided in the accelerator pedal, and can detect the opening of the accelerator pedal. The accelerator opening sensor 26 detects the accelerator opening, and transmits the detected value to the ECU 12 as an accelerator opening signal.

  The longitudinal acceleration sensor 27 is provided at a predetermined location of the vehicle body, and can detect longitudinal acceleration acting on the vehicle body. The longitudinal acceleration sensor 27 detects longitudinal acceleration and transmits the detected value to the ECU 12 as a longitudinal acceleration signal.

  The lateral acceleration sensor 28 is provided at a predetermined location of the vehicle body, and can detect the lateral acceleration acting on the vehicle body. The lateral acceleration sensor 26 detects lateral acceleration and transmits the detected value to the ECU 12 as a lateral acceleration signal.

  The yaw rate sensor 29 is provided at a predetermined location on the vehicle body and can detect the yaw rate of the vehicle body. The yaw rate sensor 29 detects the yaw rate and transmits the detected value to the ECU 12 as a yaw rate signal.

  The wheel cylinder actuators 31, 32, 33, and 34 are provided in the wheel cylinders of the front right wheel FRW, the front left wheel FLW, the rear right wheel RRW, and the rear left wheel RLW, and can adjust the hydraulic pressure of each wheel cylinder. When each wheel cylinder actuator 31, 32, 33, 34 receives a brake pressure control signal from the ECU 12, it operates based on the brake pressure control signal and can adjust the hydraulic pressure of the wheel cylinder.

  The ECU 12 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and performs overall control of the vehicle behavior control device 11. ECU12 takes in the detection signal of each sensors 21-29 for every fixed time. Moreover, ECU12 comprises the ABS control part 12a, the rotation radius shortening control part 12b, and the arbitration part 12c by running each program stored in ROM by CPU. Then, the ECU 12 performs processing of the ABS control unit 12a, the rotation radius reduction control unit 12b, and the arbitration unit 12c based on each detection signal at regular time intervals, and each wheel cylinder actuator 31, 32, 33, 34 is controlled.

  The ABS control function is mainly composed of wheel speed sensors 21, 22, 23, 24, wheel cylinder actuators 31, 32, 33, 34, and an ABS control unit 12a. The turning radius shortening control function is constituted by the wheel speed sensors 21, 22, 23, 24, the steering angle sensor 25, the accelerator opening sensor 26, the wheel cylinder actuators 31, 32, 33, 34, and the turning radius shortening control unit 12b. Is done.

  The ECU 12 calculates the wheel speed based on the wheel speed signal for each of the wheels FRW, FLW, RRW, and RLW. Then, the ECU 12 calculates the vehicle body speed based on the wheel speeds of the four wheels FRW, FLW, RRW, and RLW.

  The ABS control unit 12a calculates the slip ratio for the front wheels FRW and FLW and the rear wheels RRW and RLW as the left and right braking wheels based on the wheel speeds of the wheels FRW, FLW, RRW, and RLW and the wheel speeds of the reference wheels. To do. In this case, the reference wheel is the wheel having the highest wheel speed among the four wheels. Then, the ABS control unit 12a normally calculates the slip ratio for the left and right wheels FRW, FLW, RRW, and RLW based on the speed difference between the reference wheel and the other wheels, and this slip ratio is calculated based on the ABS control start threshold (basic Value) or more. The ABS control start threshold value is used to determine whether or not a slip occurs between the road surface and each wheel FRW, FLW, RRW, and RLW when each wheel FRW, FLW, RRW, and RLW is locked. The basic value is set in advance by experiments or the like. In particular, when the ABS control unit 12a changes the ABS control start threshold value in the arbitration unit 12c, for each wheel FRW, FLW, RRW, RLW, is the slip rate greater than the ABS control start threshold value (changed value) after the change? Determine whether or not.

  When the slip rate is determined to be equal to or higher than the ABS control start threshold value, that is, when the ABS control operation condition is satisfied, the ABS control unit 12a applies the brake to the wheel whose slip rate is determined to be equal to or higher than the ABS control start threshold value. In order to reduce the output (braking force) of the device, a target pressurization amount is set according to the slip ratio, a brake pressure control signal for setting the target pressurization amount is set, and the brake pressure control signal is set to the wheel. It transmits to the cylinder actuators 31, 32, 33, 34. The target pressurization amount is set to a smaller value as the slip ratio is larger, and is set using a map or the like showing the relationship between the target pressurization amount and the slip ratio.

  Although the basic control using the wheel speed has been described as the ABS control, in addition to the wheel speed, more complicated control is performed using the steering angle, the accelerator opening, the longitudinal acceleration, the lateral acceleration, and the yaw rate. You may do it.

  The turning radius reduction control unit 12b determines whether the vehicle is not stopped and the vehicle body speed is equal to or less than the turning radius reduction control start vehicle speed. The rotation radius shortening control start vehicle speed is a low vehicle speed for determining that the vehicle is traveling at a low speed, and is set in advance in consideration of a U-turn, a vehicle speed when parking, and the like. When it is determined that the vehicle is not stopped and the vehicle body speed is equal to or less than the rotation radius reduction control start vehicle speed, the rotation radius reduction control unit 12b determines whether the steering angle is equal to or greater than the rotation radius reduction control start steering angle. The turning radius shortening control start steering angle is a large steering angle for determining a state close to full steering, and is set in advance based on the maximum steering angle of the vehicle.

  When the vehicle is running, the vehicle body speed is less than or equal to the vehicle speed at which the turning radius reduction control is started, and the steering angle is determined to be greater than or equal to the turning radius reduction control start steering angle, that is, when the operating condition of the turning radius reduction control is satisfied, The turning radius shortening control unit 12b sets a target pressurization amount for applying a braking force to the rear turning inner wheel according to the accelerator opening, and a brake pressure control signal for setting the target pressurization amount. And the brake pressure control signal is transmitted to the wheel cylinder actuators 31, 32, 33, and 34. The target pressurization amount is set to a larger value as the accelerator opening is larger, and is set using a map or the like showing the relationship between the target pressurization amount and the accelerator opening. In this way, the target pressurization amount is set according to the accelerator opening because the braking force is actively added on the vehicle side. Therefore, in order to suppress the uncomfortable feeling caused by the braking force, the target pressurizing amount is added as the driving force becomes smaller. This is to reduce the braking force to be applied. The target pressurization amount may be set in consideration of the steering angle.

  Here, the reason why the braking force is applied to the rear turning inner wheel will be described. For example, as shown in FIG. 2, when the vehicle turns left at a low speed and a large steering angle, if a braking force is applied to the turning inner wheels FLW and RLW, a rotational moment is generated that turns the vehicle inward. Due to this rotational moment, the arm length FL of the front turning inner ring FLW and the arm length RL of the rear turning inner ring RLW pass through the center of gravity G of the vehicle, and the center of gravity axis A indicating the traveling direction of the center of gravity G of the vehicle and each turning inner ring FLW, It is the length between the RLW and the longer it is, the better the turning performance of the vehicle. Comparing the arm length FL of the front turning inner ring FLW and the arm length RL of the rear turning inner ring RLW, the arm length RL is longer. In other words, when the braking force is applied to the rear turning inner wheel RLW, the turning performance of the vehicle is improved and the minimum turning radius can be further shortened. Note that even if a braking force is applied to the front turning inner wheel FLW, the turning performance of the vehicle is improved. Therefore, a braking force may be applied to the front turning inner wheel FLW. In this case, the reference wheel is a turning inner wheel, and here is a front turning inner wheel FLW and a rear turning inner wheel RLW, and applies braking force to the reference wheel (front turning inner wheel FLW and rear turning inner wheel RLW).

  The arbitrating unit 12c determines whether or not the turning radius reduction control is being performed, that is, whether or not the operating condition of the turning radius reduction control is satisfied. If it is determined that the turning radius shortening control is in progress, the arbitrating unit 12c changes the ABS control start threshold value to a value larger than the basic value according to the amount of pressure applied to the wheel cylinder of the rear turning inner wheel so that the ABS control becomes difficult to operate. To do. The ABS control start threshold value is changed to a larger slip ratio as the pressurization amount of the wheel cylinder of the rear turning inner wheel is larger, that is, as the braking force applied to the rear turning inner wheel is larger, the ABS control start threshold value and the pressurization amount are increased. It is set using a map or the like showing the relationship between The pressurization amount of the wheel cylinder of the rear turning inner wheel may be the target pressurization amount set by the rotation radius shortening control unit 12b, or may be the pressurization amount obtained from the wheel cylinder pressure detected by the sensor.

  Here, the reason why the ABS control start threshold value is greatly changed during the turning radius reduction control will be described. When the turning radius shortening control is operating, the braking force is applied to the rear turning inner wheel, so that the wheel speed of the rear turning inner wheel is much lower than that of the other wheels. Therefore, when the turning radius shortening control is activated, the reference wheel for obtaining the slip ratio by the ABS control unit 12a is the rear turning outer wheel, the slip ratio of the rear turning inner wheel is increased, and the ABS control is more easily operated than usual. Become. For this reason, even when the rear turning inner wheel is not actually locked, the ABS control may be activated, and the braking force may be reduced with respect to the rear turning inner wheel. Therefore, during the turning radius shortening control, the ABS control start threshold value is made larger than that during normal control so that the ABS control is not easily activated. However, since there is a possibility that the rear turning inner wheel is actually locked, the ABS control is activated when the slip ratio of the rear turning inner wheel becomes greater than or equal to the greatly changed ABS control start threshold value.

  In addition, when the ABS control start threshold value is greatly changed during the turning radius shortening control, the braking force of the rear turning inner wheel is reduced by the ABS control when the slip ratio of the rear turning inner wheel exceeds the ABS control start threshold value. become. In this case, the braking force to the left and right wheels is different, and the running stability of the vehicle is reduced. Therefore, the ABS control unit 12a may make the braking force (target pressurization amount) applied to the rear turning outer wheel smaller than that during normal control.

  The operation of the vehicle behavior control apparatus 11 of the present embodiment configured as described above will be described. In the following description, a case where the vehicle makes a U-turn from a state where the vehicle is stopped in the intersection will be described. In particular, the processing in the arbitration unit 12c of the ECU 12 will be described based on the flowchart of FIG.

  In the vehicle behavior control apparatus 11 of the present embodiment, as shown in FIGS. 1 and 3, the wheel speed sensors 21, 22, 23, and 24 detect the rotational speed of each wheel and transmit a wheel speed signal to the ECU 12. doing. The steering angle sensor 25 detects a steering angle and transmits a steering angle signal to the ECU 12. The accelerator opening sensor 26 detects the accelerator opening and transmits an accelerator opening signal to the ECU 12. The longitudinal acceleration sensor 27 detects longitudinal acceleration and sends a longitudinal acceleration signal to the ECU 12. Further, the lateral acceleration sensor 28 detects lateral acceleration and transmits a lateral acceleration signal to the ECU 12. The yaw rate sensor 29 detects the yaw rate and transmits a yaw rate signal to the ECU 12.

  In step S11, the ECU 12 receives detection signals from the sensors 21 to 29 at regular time intervals. The ECU 12 calculates the wheel speed of each wheel, and further calculates the vehicle body speed from the wheel speed of each wheel.

  The turning radius shortening control unit 12b of the ECU 12 determines whether or not the vehicle is not stopped at regular intervals, the vehicle body speed is equal to or less than the turning radius shortening control start vehicle speed, and the steering angle is equal to or greater than the turning radius shortening control start steering angle. Determine. Here, when the vehicle is stopped in the intersection waiting for the oncoming vehicle to pass, the turning radius reduction control unit 12b determines that the vehicle is stopped and does not start the turning radius reduction control.

  When the oncoming vehicle passes, the vehicle starts a U-turn and travels at a low speed and a large steering angle in the right turn direction. Then, the turning radius shortening control unit 12b determines that the vehicle body speed is equal to or less than the turning radius shortening control start vehicle speed and the steering angle is equal to or more than the turning radius shortening control start steering angle while traveling, and starts the turning radius shortening control. . Then, the turning radius shortening control unit 12b sets a brake pressure control signal for the rear turning inner wheel (right wheel) according to the accelerator opening, and transmits the brake pressure control signal to the wheel cylinder actuators 31 and 33. To do. The right wheel wheel cylinder actuators 31 and 33 operate in response to a brake pressure control signal to increase the hydraulic pressure of the wheel cylinder. As a result, a braking force is applied to the right wheel, and a rotational moment directed in the right direction is generated in the vehicle. As a result, the minimum turning radius of the vehicle is reduced during the U-turn. Note that braking force may be applied only to the front right wheel or only to the rear right wheel, and in either case, the wheel speed of the right wheel is lower than that of the left wheel.

  In step S12, the arbitrating unit 12c of the ECU 12 determines whether or not the turning radius reduction control is being performed at regular time intervals. Here, when the vehicle is stopped in the intersection, the arbitrating unit 12c determines that the turning radius reduction control is not being performed, and ends this routine without performing any processing. On the other hand, when the vehicle starts a U-turn, the arbitrating unit 12c determines that the turning radius reduction control is being performed, and proceeds to step S13. In step S13, the arbitrating unit 12c determines whether or not the slip ratio has exceeded the ABS control start threshold value. Here, if it is determined that the slip ratio is equal to or less than the ABS control start threshold value, this routine is terminated without performing any processing. On the other hand, if it is determined that the slip ratio has exceeded the ABS control start threshold value, in step S14, the ABS control start threshold value is changed to a value that makes it difficult to start control, that is, a value larger than the basic value.

  At this time, the ABS control unit 12a of the ECU 12 calculates a slip ratio based on the wheel speed for each drive wheel at regular time intervals, and determines whether or not the slip ratio is equal to or greater than an ABS control start threshold value. In this case, the ABS control start threshold is a basic value when the turning radius shortening control is not being performed, and is a changed value greatly changed by the arbitration unit 12c when the turning radius shortening control is being performed.

  And the ABS control part 12a does not start ABS control, when it determines with a slip ratio being less than an ABS control start threshold value. On the other hand, the ABS control part 12a operates ABS control, when it determines with a slip ratio being more than an ABS control start threshold value. Then, the ABS control unit 12a sets a target pressurization amount according to the slip rate for the wheel whose slip rate is determined to be equal to or higher than the ABS control start threshold, and a brake pressure control signal for setting the target pressurization amount. And the brake pressure control signal is transmitted to the wheel cylinder actuators 31, 32, 33, and 34. The wheel cylinder actuators 31, 32, 33, and 34 operate based on the brake pressure control signal, and the braking force of a predetermined wheel decreases. In other words, the wheel cylinder actuator of the locked wheel operates in response to the brake pressure control signal, and reduces the hydraulic pressure of the wheel cylinder. As a result, the braking force of the locked wheel is reduced, and as a result, the wheel is unlocked.

  In particular, when the turning radius shortening control is operating, the wheel speed of the right wheel is much lower than that of the left wheel due to the addition of braking force and the difference in the turning inner wheel. Therefore, the slip ratio of the left wheel becomes larger than that during normal control. However, since the ABS control start threshold is also changed to a value larger than that during normal control, if the right wheel is actually locked and the slip ratio does not become very large, the slip ratio of the right wheel is greater than or equal to the ABS control start threshold. The ABS control does not start. Therefore, the braking force is not reduced for the left and right wheels, and the vehicle can smoothly make a U-turn with a small turning radius.

  When the rotation radius shortening control is operated by the rotation radius shortening control unit 12b of the ECU 12, if the driver performs a brake operation, the rotation radius shortening control unit 12b continues the operation of the rotation radius shortening control. In this case, the wheel cylinder pressure at the time of control is introduced unless the master cylinder pressure becomes larger than the wheel cylinder pressure at the time of control in the brake device.

  As described above, in the vehicle behavior control device of the first embodiment, the ABS control unit 12a that executes the braking force control based on the speed difference between the left and right wheels, and the turning control (the turning radius shortening control) based on the braking force difference between the left and right wheels. The rotation radius shortening control unit 12b to be executed and the arbitration unit 12c that suppresses the braking force control by the ABS control unit 12a when the rotation radius shortening control by the rotation radius shortening control unit 12b is executed are provided.

  Therefore, when the rotation radius shortening control by the rotation radius shortening control unit 12b is being performed, the braking force control by the ABS control unit 12a is suppressed, so that unnecessary ABS control can be performed in a situation where the wheels are not locked. The operation can be suppressed and the necessary ABS control can be activated when the wheel is locked. As a result, even when the turning radius shortening control is being executed, the optimum ABS control can be executed, interference between the turning radius shortening control and the ABS control can be suppressed, and the running stability of the vehicle can be reduced. Can be improved.

  Further, in the vehicle behavior control device of the first embodiment, the arbitration unit 12c is difficult to operate the ABS control start threshold value in the ABS control unit 12a when the rotation radius reduction control by the rotation radius reduction control unit 12b is executed. I try to change it to a larger value. In this case, the ABS control start threshold value in the ABS control unit 12a is changed to a value that makes the ABS control difficult to operate as the driving force difference between the left and right wheels in the rotation radius reduction control by the rotation radius reduction control unit 12b increases.

  Therefore, when the turning radius shortening control is performed, the interference between the turning radius shortening control and the ABS control can be easily suppressed by changing the ABS control start threshold value to a value that is difficult to control.

In the vehicle behavior control apparatus of the first embodiment, in the turning radius shortening control by the turning radius shortening control unit 12b, the turning inner wheel is set as the reference wheel, and a braking force larger than that of the other wheels is applied to the reference wheel. . In the ABS control by the ABS control unit 12a, a wheel having a high wheel speed is set as a reference wheel, and a braking force to be applied is adjusted based on a speed difference between the reference wheel and another wheel.
Accordingly, the rotation radius shortening control and the ABS control unit 12a can be properly executed.

  In the vehicle behavior control device of the first embodiment, the turning radius reduction control unit 12b performs turning control when the vehicle speed is equal to or less than a predetermined vehicle speed that is set in advance and the steering angle is equal to or greater than a predetermined steering angle that is set in advance. Run. Therefore, the turning radius when turning the vehicle can be appropriately reduced.

  In the vehicle behavior control apparatus of the first embodiment, the turning radius shortening control unit 12b determines the driving force difference between the left and right wheels according to at least one of the accelerator operation amount and the steering angle. Accordingly, the braking force of the turning inner wheel can be set to an appropriate value during the vehicle turning radius reduction control.

[Embodiment 2]
FIG. 4 is a flowchart showing the flow of processing by the vehicle behavior control apparatus according to the second embodiment of the present invention. Note that the overall configuration of the vehicle behavior control device of the present embodiment is substantially the same as that of the first embodiment described above, and will be described with reference to FIG. 1 and a member having the same function as that described in the present embodiment. Are denoted by the same reference numerals and redundant description is omitted.

  The vehicle behavior control device of the second embodiment has at least an ABS function and a turning radius shortening control function, and stops the operation of the ABS control during the turning radius shortening control.

  In the second embodiment, as shown in FIG. 1, the ECU 12 includes an ABS control unit 12a, a rotation radius shortening control unit 12b, and an arbitration unit 12c, and is based on detection signals from the sensors 21 to 29. Processing is performed by the ABS control unit 12a, the rotation radius shortening control unit 12b, and the arbitration unit 12c, and the driving of the wheel cylinder actuators 31, 32, 33, and 34 is controlled as necessary.

  Since the ABS control unit 12a and the turning radius shortening control unit 12b are the same as those in the first embodiment, detailed description thereof is omitted. The arbitrating unit 12c determines whether or not the turning radius reduction control is being performed, that is, whether or not the operating condition of the turning radius reduction control is satisfied. When it is determined that the turning radius reduction control is being performed, the arbitrating unit 12c stops the ABS control operation by the ABS control unit 12a.

  Here, operation | movement of the vehicle behavior control apparatus 11 of this embodiment is demonstrated. As shown in FIG.1 and FIG.4, in step S21, ECU12 receives a detection signal from each sensor 21-29 for every fixed time, calculates the wheel speed of each wheel, Furthermore, the further each wheel's The vehicle speed is calculated from the wheel speed.

  The turning radius shortening control unit 12b of the ECU 12 determines whether or not the vehicle is not stopped at regular intervals, the vehicle body speed is equal to or less than the turning radius shortening control start vehicle speed, and the steering angle is equal to or greater than the turning radius shortening control start steering angle. Determine. Here, when the vehicle is stopped in the intersection waiting for the oncoming vehicle to pass, the turning radius reduction control unit 12b determines that the vehicle is stopped and does not start the turning radius reduction control. When the oncoming vehicle passes, the vehicle starts a U-turn and travels at a low speed and a large steering angle in the right turn direction. Then, the turning radius shortening control unit 12b determines that the vehicle body speed is equal to or less than the turning radius shortening control start vehicle speed and the steering angle is equal to or more than the turning radius shortening control start steering angle while traveling, and starts the turning radius shortening control. .

  In step S22, the arbitrating unit 12c of the ECU 12 determines whether or not the turning radius reduction control is being performed at regular time intervals. Here, when the vehicle is stopped in the intersection, the arbitrating unit 12c determines that the turning radius reduction control is not being performed, and ends this routine without performing any processing. On the other hand, when the vehicle starts a U-turn, the arbitrating unit 12c determines that the turning radius shortening control is in progress, and proceeds to step S23. In step S23, the arbitrating unit 12c determines whether or not the slip rate has exceeded the ABS control start threshold value. Here, if it is determined that the slip ratio is equal to or less than the ABS control start threshold value, this routine is terminated without performing any processing. On the other hand, if it is determined that the slip ratio has exceeded the ABS control start threshold, the ABS control by the ABS control unit 12a is stopped in step S24.

  In this case, when the turning radius shortening control is activated, the wheel speed of the right wheel is much lower than that of the left wheel due to the addition of braking force and the difference in the turning inner wheel. Therefore, the slip ratio of the left wheel becomes larger than that during normal control. However, since the ABS control is stopped, the braking force is not reduced for both the left and right wheels, and the vehicle can smoothly make a U-turn with a small turning radius.

  As described above, in the vehicle behavior control apparatus according to the second embodiment, the arbitration unit 12c performs ABS control (braking force control) by the ABS control unit 12a when the rotation radius reduction control is executed by the rotation radius reduction control unit 12b. Has stopped working. Therefore, it is possible to suppress unnecessary ABS control operation in a situation where the wheels are not locked. As a result, interference between the turning radius shortening control and the ABS control can be suppressed, and the running stability of the vehicle can be improved.

[Embodiment 3]
FIG. 5 is a flowchart showing the flow of processing by the vehicle behavior control apparatus according to the third embodiment of the present invention. Note that the overall configuration of the vehicle behavior control device of the present embodiment is substantially the same as that of the first embodiment described above, and will be described with reference to FIG. 1 and a member having the same function as that described in the present embodiment. Are denoted by the same reference numerals and redundant description is omitted.

  The vehicle behavior control apparatus of the third embodiment has at least an ABS function and a turning radius shortening control function, and stops the turning radius shortening control operation when the ABS control operating condition is satisfied during the turning radius shortening control. Is.

  In the third embodiment, as shown in FIG. 1, the ECU 12 includes an ABS control unit 12a, a turning radius shortening control unit 12b, and an arbitration unit 12c, and is based on detection signals from the sensors 21 to 29. Processing is performed by the ABS control unit 12a, the rotation radius shortening control unit 12b, and the arbitration unit 12c, and the driving of the wheel cylinder actuators 31, 32, 33, and 34 is controlled as necessary.

  Since the ABS control unit 12a and the turning radius shortening control unit 12b are the same as those in the first embodiment, detailed description thereof is omitted. The arbitrating unit 12c determines whether or not the turning radius reduction control is being performed, that is, whether or not the operating condition of the turning radius reduction control is satisfied. When it is determined that the turning radius reduction control is being performed, the arbitrating unit 12c determines whether or not the ABS control operation condition is satisfied. And when it determines with the operating condition of ABS control having been satisfied, the arbitration part 12c stops the action | operation of the turning radius shortening control by the turning radius shortening control part 12b.

  Here, operation | movement of the vehicle behavior control apparatus 11 of this embodiment is demonstrated. As shown in FIG.1 and FIG.5, in step S31, ECU12 receives a detection signal from each sensor 21-29 for every fixed time, calculates the wheel speed of each wheel, Furthermore, the further each wheel's The vehicle speed is calculated from the wheel speed.

  The turning radius shortening control unit 12b of the ECU 12 determines whether or not the vehicle is not stopped at regular intervals, the vehicle body speed is equal to or less than the turning radius shortening control start vehicle speed, and the steering angle is equal to or greater than the turning radius shortening control start steering angle. Determine. Here, when the vehicle is stopped in the intersection waiting for the oncoming vehicle to pass, the turning radius reduction control unit 12b determines that the vehicle is stopped and does not start the turning radius reduction control. When the oncoming vehicle passes, the vehicle starts a U-turn and travels at a low speed and a large steering angle in the right turn direction. Then, the turning radius shortening control unit 12b determines that the vehicle body speed is equal to or less than the turning radius shortening control start vehicle speed and the steering angle is equal to or more than the turning radius shortening control start steering angle while traveling, and starts the turning radius shortening control. .

  In step S32, the arbitrating unit 12c of the ECU 12 determines whether or not the turning radius reduction control is being performed at regular time intervals. Here, when the vehicle is stopped in the intersection, the arbitrating unit 12c determines that the turning radius reduction control is not being performed, and ends this routine without performing any processing. On the other hand, when the vehicle starts a U-turn, the arbitrating unit 12c determines that the turning radius shortening control is being performed, and proceeds to step S33. In step S33, the arbitrating unit 12c determines whether or not the slip ratio has exceeded the ABS control start threshold value. Here, if it is determined that the slip ratio is equal to or less than the ABS control start threshold, it is determined that the ABS control operation condition is not satisfied, and this routine is terminated without performing any processing. On the other hand, if it is determined that the slip ratio has exceeded the ABS control start threshold value, it is determined that the ABS control operation condition is satisfied, and in step S34, the rotation radius reduction control by the rotation radius reduction control unit 12b is stopped.

  In this case, when the turning radius shortening control is activated, the wheel speed of the right wheel is much lower than that of the left wheel due to the addition of braking force and the difference in the turning inner wheel. Therefore, the slip ratio of the left wheel becomes larger than that during normal control, and ABS control is activated. However, at this time, since the turning radius shortening control is stopped, the running stability of the vehicle is not lowered, and the appropriate ABS control is possible, the wheel lock is suppressed, and the vehicle has an appropriate braking force. Can be granted.

  As described above, in the vehicle behavior control apparatus according to the third embodiment, the arbitration unit 12c has the ABS control (braking force control) operating condition when the rotation radius reduction control is executed by the rotation radius reduction control unit 12b. When it is established, the operation of the rotation radius reduction control by the rotation radius reduction control unit 12b is stopped. Accordingly, it is possible to suppress the lock of the wheel during the turn and execute an appropriate ABS control operation. As a result, interference between the turning radius shortening control and the ABS control can be suppressed, and the running stability of the vehicle can be improved.

  In the above-described embodiment, the vehicle behavior control apparatus of the present invention has been described. However, the present invention is not limited to each embodiment and can be implemented in various forms. For example, although each embodiment is applied to a rear wheel drive vehicle, it can also be applied to a four wheel drive vehicle or a front wheel drive vehicle.

  Further, in each embodiment, the turning radius shortening control and the ABS control for performing the brake control for each wheel are applied, but the present invention can be applied to those for performing the brake control and the engine control (throttle control) for each wheel.

  In each embodiment, the ABS control is made difficult to operate during the turning radius shortening control and the ABS control is stopped. However, during the turning radius shortening control, the amount of braking force reduction by the ABS control is normally set. You may make it reduce from the time of control. In each embodiment, the ABS control control start threshold is changed to a value that makes it difficult to start control during the turning radius shortening control, or the ABS control is stopped. However, the ABS is controlled at the timing when the turning radius shortening control starts. It is good also as a structure which changes a control control start threshold value to the value which becomes difficult to start control, or stops ABS control.

  Furthermore, in each embodiment, the turning radius shortening control for performing the brake control for each wheel is applied. However, the vehicle behavior control device of the present invention is applied to a hybrid vehicle using both the engine and the motor, and the turning radius shortening control is performed. The turning radius shortening control may be executed by reducing the driving force of the turning inner wheel by regenerative control using an engine brake or a motor.

  As described above, the vehicle behavior control device according to the present invention suppresses the interference between the turning control of the vehicle and the braking force control, and is useful for a device that stably controls the traveling of the vehicle.

11 Vehicle Behavior Control Device 12 ECU
12a ABS control unit 12b Turning radius shortening control unit 12c Arbitration unit 21, 22, 23, 24 Wheel speed sensor 25 Steering angle sensor 26 Accelerator opening sensor 27 Longitudinal acceleration sensor 28 Lateral acceleration sensor 29 Yaw rate sensor 31, 32, 33, 34 Wheel cylinder actuator

Claims (5)

A first control device that performs turning control based on a driving force difference or a braking force difference between left and right wheels;
A second control device that executes braking force control based on a speed difference between the left and right wheels;
An arbitration device that suppresses braking force control by the second control device when turning control by the first control device is executed;
Equipped with a,
When the turning control by the first control device is executed, the arbitration device changes the control threshold value in the second control device to a value that makes it difficult to operate the braking force control,
The arbitration device changes the control threshold value in the second control device to a value that makes it difficult to operate the braking force control as the difference in driving force between the left and right wheels in the turning control by the first control device increases.
The vehicle behavior control apparatus characterized by the above-mentioned. Wherein in accordance with the turning control is first controller, the turning inner wheel is set as the reference wheel, the first control apparatus, according to claim 1, wherein applying a large braking force than the other wheel with respect to the reference wheel The vehicle behavior control device described in 1. In the braking force control by the second control device, a wheel having a high wheel speed is set as a reference wheel, and the second control device adjusts a braking force to be applied according to a speed difference between the reference wheel and another wheel. The vehicle behavior control device according to claim 1 , wherein The first control apparatus, a vehicle speed below a predetermined vehicle speed that is set in advance, and, from claim 1, characterized in that to perform the turning control when the steering angle is equal to or larger than a predetermined steering angle previously set in the 3 The vehicle behavior control device according to any one of the above. 5. The vehicle behavior control device according to claim 1, wherein the first control device determines a driving force difference between left and right wheels according to at least one of an accelerator operation amount and a steering angle. 6. .

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