JP2015044531A - Vehicular control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deviation of a vehicular body attitude when the vehicle is stopped after an anti-lock brake system (ABS) stopped operating.SOLUTION: If an ABS ECU 2 as detection means detects existence of deviation in the center of gravity immediately before the ABS ECU 2 stops operation of an ABS after a vehicle 1 is decelerated down to a given vehicular speed V1 at which the operation of the ABS is to be ended according to the operation of a brake by a driver, the vehicular speed V1 at which anti-lock brake control is to be ended for a wheel on a side with no deviation of the center of gravity is changed to a speed V2 (<V1) lower than a speed on a side with deviation of the center of gravity, with the anti-lock brake control for the wheel on the side with the deviation of the center of gravity ended when the vehicular speed is decelerated to the speed V1, while the anti-lock brake control for the wheel on the side with no deviation of the center of gravity is further continued, and ended when the vehicle is decelerated to the speed V2 (<V1).

Description

  The present invention relates to a vehicle control device that performs antilock brake control for each of left and right wheels by operating an antilock brake system in order to reduce the occurrence of sliding due to wheel locking.

  Conventionally, when the vehicle is suddenly braked or the road surface is frozen, the brake control is performed separately for the left and right wheels in order to maintain the vehicle body posture without locking the wheels. ) Has been developed that is equipped with a so-called anti-lock brake system (ABS).

  By the way, in this type of ABS-equipped vehicle, if the host vehicle is decelerated while the operation of the ABS is continued, the host vehicle cannot be stopped indefinitely. Therefore, the vehicle speed of the host vehicle becomes equal to or lower than a predetermined vehicle speed. At times, it is common to control the vehicle so that the vehicle can be stopped by stopping the operation of the ABS so that the wheels can be locked.

JP-A-61-218463 (see page 6, upper left column, line 9 to lower left column, line 11 and FIG. 1)

  However, in the above-described ABS-equipped vehicle, when the operation of the ABS is terminated and the vehicle stops, an unbalance in which the center of gravity of the vehicle body is biased to the left or right occurs, or the wheel of the own vehicle is caused by freezing of the road surface. There is a risk that the body posture at the time of stoppage may be deflected due to a difference between the left and right wheels in the coefficient of friction between the vehicle and the road surface. Conventionally, the vehicle body deflection at the time of stop after such ABS operation has been completed has been improved. Was impossible.

  An object of the present invention is to avoid the deflection of the vehicle body posture at the time of stopping after the operation of an ABS (anti-lock brake system) ends.

  In order to achieve the above-described object, the vehicle control device of the present invention is for a vehicle that performs antilock brake control for each of the left and right wheels by operating an antilock brake system in order to reduce the occurrence of sliding due to wheel locking. In the control device, detection means for detecting whether the center of gravity of the own vehicle is biased to the left and right, and whether there is a difference between the friction coefficient between the wheel and the road surface between the left and right wheels, and the anti-lock brake when the own vehicle decelerates Immediately before stopping the operation of the system, if the detecting means detects a deviation of the center of gravity or a difference in coefficient of friction between the left and right wheels, the wheel on the side with no deviation of the center of gravity or the higher coefficient of friction The anti-lock brake system is set so that the end vehicle speed at which the anti-lock brake control should be finished is lower than the side where the center of gravity is biased or the side where the friction coefficient is low. It is characterized in that it comprises a Gosuru control means (claim 1).

  The vehicle control device of the present invention is a vehicle control device that performs antilock brake control for each of the left and right wheels by operating an antilock brake system in order to reduce the occurrence of sliding due to wheel locking. Detection means for detecting whether the center of gravity is biased to the left and right, and whether there is a difference in friction coefficient between the wheels and the road surface between the left and right wheels, and immediately before the vehicle decelerates to stop the operation of the anti-lock brake system In addition, when the detecting means detects that the center of gravity is biased or the friction coefficient is different between the left and right wheels, the anti-lock brake control of the wheel on the side where the center of gravity is not biased or on the side where the friction coefficient is high is detected. Control means for controlling the anti-lock brake system so that the end timing is delayed from the side where the center of gravity is biased or the side where the friction coefficient is low. It is characterized in Rukoto (claim 2).

  According to the first aspect of the invention, immediately before the host vehicle decelerates and stops the operation of the anti-lock brake system, there is a deviation of the center of gravity by the detecting means, or there is a difference in friction coefficient between the left and right wheels and the road surface. Is detected, the end vehicle speed of the anti-lock brake control of the wheel on the side where the center of gravity is not biased or the side where the friction coefficient is high becomes lower than the side where the center of gravity is biased or the side where the friction coefficient is low. Thus, the anti-lock brake system is controlled in such a way that the wheel on the side where the center of gravity is not biased or the side where the friction coefficient is high is locked later than the wheel on the side where the center of gravity is biased or where the friction coefficient is low, As a result, it is possible to avoid the deflection of the vehicle body posture at the time of stopping due to the locking of the wheel on the side where the center of gravity is not biased or the side where the friction coefficient is high.

  At this time, the end vehicle speed of the anti-lock brake control of the wheel on the side where the center of gravity is not biased or the side where the friction coefficient is high may be uniformly reduced to a vehicle speed determined experimentally in advance, or the degree of center of gravity bias For each difference in friction coefficient between the left and right wheels and the road surface, the relationship between the end vehicle speed is experimentally obtained in advance and the relationship between the degree of center of gravity deviation and the end vehicle speed is mapped, The end vehicle speed of the antilock brake control for the wheel with the higher friction coefficient may be lowered to the vehicle speed read from the map.

  Further, according to the invention of claim 2, immediately before the host vehicle decelerates and stops the operation of the antilock brake system, there is a deviation of the center of gravity by the detecting means, or the friction coefficient between the left and right wheels and the road surface. When a difference is detected, the control means causes the end timing of the antilock brake control of the wheel on the side where the center of gravity is not biased or the friction coefficient is higher than the side where the center of gravity is biased or the side where the friction coefficient is low. Since the anti-lock brake system is controlled so as to be delayed, the wheel that is not biased at the center of gravity or the wheel with the higher coefficient of friction locks more slowly than the wheel with the biased center of gravity or the side with the lower coefficient of friction. As a result, it is possible to avoid the occurrence of the deflection of the vehicle body posture due to the locking of the wheel on which the center of gravity is not biased or the friction coefficient is high.

  At this time, the end timing of the anti-lock brake control of the wheel on the side where the center of gravity is not biased or on the side where the friction coefficient is high may be uniformly delayed by a predetermined time determined experimentally in advance. For each difference between the degree and the friction coefficient with the road surface between the left and right wheels, the relationship between the delay time is experimentally obtained in advance and the relationship between the degree of center of gravity deviation and the delay time is mapped, and the side without the center of gravity deviation Or you may make it delay the completion | finish timing of the antilock brake control of the wheel with a higher friction coefficient by the delay time read from the map.

1 is a block diagram of a first embodiment of a vehicle control device according to the present invention. FIG. It is explanatory drawing of the biased state of the gravity center in the right and left of the vehicle of 1st Embodiment. It is a flowchart for operation | movement description of 1st Embodiment. It is a flowchart for operation | movement description of 2nd Embodiment.

(First embodiment)
Next, a vehicle control apparatus according to a first embodiment of the present invention will be described in detail with reference to the block diagram of FIG. 1, the operation explanatory diagrams of FIGS.

  As shown in FIG. 1, the vehicle 1 in the present embodiment is equipped with an anti-lock brake system (ABS), and is provided with an ABS ECU (Engine Control Unit) 2 for controlling the ABS. The brake actuator 3 is controlled, and cylinder pressure is applied to the right wheel cylinder 4R that applies braking force to the right wheel and the left wheel cylinder 4L that applies braking force to the left wheel, and the left and right wheels are braked.

  Further, as shown in FIG. 1, a yaw rate sensor 5 for detecting the yaw rate of the vehicle is provided in order to detect the deviation of the center of gravity on the left and right of the vehicle (own vehicle) 1, and the wheel speed sensor 6 for detecting the wheel speed is provided. The detection signals of both the sensors 5 and 6 are taken into the ABS ECU 2. Based on the yaw rate detected by the yaw rate sensor 5, the ABS ECU 2 detects whether or not the center of gravity of the vehicle 1 is biased to the left and right. When the yaw rate sensor is not provided, the yaw rate may be obtained from the difference between the left and right wheel speed sensor values. Thus, the detection process of the presence or absence of the deviation of the center of gravity of the vehicle 1 by the ABS ECU 2 corresponds to the detection means in the present invention.

  Then, immediately before the vehicle 1 is decelerated to a predetermined vehicle speed V1 at which the operation of the ABS is terminated by the driver's braking operation and the ABS operation is stopped by the ABS ECU 2, the ABS ECU 2 as the detecting means detects that the center of gravity is biased. Then, the end vehicle speed V1 at which the anti-lock brake control of the wheel on the side where the center of gravity is not biased should be ended is switched to V2 (<V1) lower than the side where the center of gravity is biased, and the side where the center of gravity is biased is switched. The antilock brake control of the wheel is finished when the vehicle speed is reduced to V1, while the antilock brake control of the wheel on the side where the center of gravity is not biased is further continued to reduce the vehicle speed to V2 (<V1). It ends at the time.

  Therefore, immediately before the vehicle 1 stops the operation of the ABS by the ABS ECU 2, if the ABS ECU 2 detects that the center of gravity is biased to the right side, for example, when the vehicle 1 decelerates to V1, the right anti-lock with the center of gravity biased. The brake control is terminated and the right wheel is locked based on the driver's brake operation. However, the pressure in the left wheel cylinder 4L is reduced more than that in the right wheel cylinder 4R, and the left antilock brake control is reduced to the vehicle speed V2. Until the vehicle speed V2 is decelerated, the left wheel without the deviation of the center of gravity is not locked, and the deviation of the vehicle body posture due to the deviation of the center of gravity can be avoided.

  Next, the switching operation of the end vehicle speed of the antilock brake control when the center of gravity is biased will be described with reference to the flowchart of FIG.

  As shown in FIG. 3, when the brake operation is performed by the driver, the ABS ECU 2 determines whether or not the ABS needs to be operated based on the yaw rate detected by the yaw rate sensor 5 (step S1). If the result is NO, the operation is terminated, and if the determination result in step S1 is YES, it is determined whether or not there is a bias in the center of gravity on the left and right of the vehicle 1 (step S2).

  If the determination result in step S2 is NO, the operation ends. If YES, in the next step S3, the end vehicle speed V1 to end the antilock brake control of the wheel on the side where the center of gravity is not biased is It is switched to V2 (<V1) lower than the side where the center of gravity is biased (step S3), and the wheel cylinder 4R or 4L corresponding to one wheel which is the side where the center of gravity is not biased is reduced until the vehicle speed decreases to V2. The pressure is reduced from the wheel cylinder 4L or 4R for the other wheel, the anti-lock brake control on the side where the center of gravity is not biased is continued, and then the anti-lock brake control which has been continued when the vehicle speed reaches V2 is also ended. And all operations are finished.

  For example, as shown in FIG. 2 showing the vehicle 1 in plan view, immediately before the vehicle 1 is decelerated by the brake operation and the vehicle speed is reduced to the end vehicle speed V1 at which the operation of the ABS is stopped and the antilock brake control should be terminated. When it is determined that there is a deviation of the center of gravity G on the right side, when the anti-lock brake control of the left and right wheels is finished simultaneously, the left direction indicated by the arrow in FIG. The rotation moment toward the vehicle becomes larger than the rightward rotation moment, and the vehicle 1 stops in a state of rotating leftward and deflecting leftward. In FIG. 2, FL and RL are the left front and rear wheels, and FR and RR are the right front and rear wheels.

  Therefore, when the ABS ECU 2 determines that there is a bias in the center of gravity on the right side, as described above, the end vehicle speed at which the antilock brake control for the left wheel without the center of gravity deviation should be terminated is set to V2 lower than V1. By switching, the anti-lock brake control for the right wheel with the bias of the center of gravity is terminated when the vehicle is decelerated to the end vehicle speed V1, whereas the anti-lock brake control for the left wheel without the bias of the center of gravity is Until the vehicle speed is reduced to V2 (<V1) and until the vehicle speed reaches V2, the left wheel without the deviation of the center of gravity is not locked, and the deviation of the vehicle body posture can be avoided in advance.

  Here, the end vehicle speed V2 of the antilock brake control of the wheel on the side where the center of gravity is biased may be, for example, a predetermined vehicle speed (= V2) determined experimentally in advance. In addition, the relationship between the end vehicle speed is experimentally obtained in advance for each degree of center of gravity deviation, and the relationship between the degree of center of gravity deviation and the end vehicle speed is mapped, and the vehicle speed read from the map is determined according to the degree of center of gravity deviation. The end vehicle speed may be appropriately switched and set.

  Therefore, according to the first embodiment described above, when the ABS ECU 2 detects that the center of gravity is biased immediately before the vehicle 1 decelerates and stops the operation of the ABS (anti-lock brake system), the ABS ECU 2 Since the ABS is controlled so that the end vehicle speed of the anti-lock brake control of the non-biased wheel is lower than the side where the center of gravity is biased, the wheel on the side without the center of gravity has a center of gravity bias. The locking timing is delayed with respect to the wheels on the side, and it becomes possible to avoid the deflection of the vehicle body posture when stopping.

(Second Embodiment)
A second embodiment of the vehicle control device according to the present invention will be described with reference to the flowchart of FIG. In addition, since the block configuration of the vehicle control device in the present embodiment is the same as that in FIG. 1, the following mainly describes differences from the first embodiment with reference to FIG. 1.

  The ABS ECU 2 detects whether the center of gravity of the vehicle 1 is biased from the yaw rate detected by the yaw rate sensor 5. When the yaw rate sensor is not provided, the yaw rate may be obtained from the difference between the left and right wheel speed sensor values. This is the same as in the first embodiment described above.

  Then, just before the vehicle 1 is decelerated to a predetermined vehicle speed V1 at which the operation of the ABS is terminated by the driver's brake operation and the ABS operation is stopped by the ABS ECU 2, the ABS ECU 2 serving as the eccentric center of gravity detection means has a center of gravity deviation. When detected, the end timing of the anti-lock brake control of the wheel on the side where the center of gravity is not biased is switched to a timing delayed by Δt time from the side where the center of gravity is biased. The lock brake control is terminated when the vehicle speed is reduced to V1, while the pressure of the wheel cylinder 4R or 4L for one wheel on the side where the center of gravity is not biased is reduced more than the wheel cylinder 4L or 4R for the other wheel. The anti-lock brake control on the side where the center of gravity is not biased is further continued for Δt time, The anti-lock brake control on the side where the center of gravity is not biased is terminated after Δt time.

  Therefore, for example, immediately before the vehicle 1 stops the operation of the ABS by the ABS ECU 2, if the ABS ECU 2 detects that the center of gravity is biased to the right side, when the vehicle 1 decelerates to V1, the right anti-lock brake with the center of gravity biased. The control is terminated and the right wheel is locked based on the driver's brake operation, but the left antilock brake control is continued for a further Δt time, while the left wheel without the center of gravity bias is not locked. Thus, the deflection of the vehicle body can be avoided in advance.

  Then, the operation procedure for changing the vehicle speed at the end of the anti-lock brake control when there is a bias in the center of gravity will be described with reference to the flowchart of FIG. 4. When the brake operation by the driver is performed as shown in FIG. Based on the yaw rate detected by the yaw rate sensor 5, the ABS ECU 2 determines whether or not ABS operation is necessary (step S11). If the determination result is NO, the operation ends, and the determination result of step S11 If YES, it is determined whether or not there is a bias in the center of gravity on the left and right of the vehicle 1 (step S12).

  If the determination result in step S12 is NO, the operation ends. If YES, in the next step S13, the end timing of the antilock brake control of the wheel on the side where the center of gravity is not biased is predetermined Δt. Delayed by time (step S13), and then the operation ends.

  Therefore, according to the second embodiment described above, when the ABS ECU 2 detects that the center of gravity is biased immediately before the vehicle 1 decelerates and stops the operation of the ABS (anti-lock brake system), the ABS ECU 2 detects the center of gravity. Since the ABS is controlled so that the end timing of the anti-lock brake control on the non-biased wheel is delayed by Δt time from the side on which the center of gravity is biased, the wheel on the side without the center of gravity is The locking timing is later than that of the wheel on the side, so that it is possible to avoid the deflection of the vehicle body when stopping.

  Note that the delay time Δt does not have to be the above-mentioned fixed time. The relationship between the delay time and the delay time is experimentally obtained in advance for each degree of bias of the center of gravity, and the relationship between the bias degree of the center of gravity and the delay time is mapped. The end timing of the antilock brake control for the wheel on the side where the center of gravity is not biased may be delayed by the time read from the map.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention.

  For example, in the first embodiment described above, based on the yaw rate detected by the yaw rate sensor 5, the presence / absence of the center of gravity deviation on the left and right of the vehicle 1 is detected, and the antilock brake control of the wheel on the side without the center of gravity deviation is terminated. The power end vehicle speed is switched to V2 (<V1) which is lower than the side where the center of gravity is biased. However, the ABSECU2 determines the left and right wheels from the vehicle speed detected by the wheel speed sensor 6 and the left and right wheel speeds. The friction coefficient between the vehicle and the road surface (hereinafter referred to as road surface μ) is derived, and the presence or absence of the difference between the derived left and right road surface μ is detected, and the vehicle (own vehicle) 1 decelerates to operate the ABS. When a difference in road surface μ between right and left wheels is detected immediately before stopping the vehicle, the ABS ECU 2 sets the end vehicle speed of the antilock brake control of the wheel on the higher road surface μ to the road surface μ The ABS may be controlled to be lower than the lower side.

  At this time, by switching the end vehicle speed at which the antilock brake control of the wheel on the road surface μ side should be terminated to V2 lower than V1, the antilock brake control on the wheel on the road surface μ side becomes the end vehicle speed V1. The anti-lock brake control of the wheel having the higher road surface μ is continued until the vehicle speed decreases to V2 (<V1), while the road speed μ is decreased until the vehicle speed becomes V2. The high-side wheel is not locked, and deviation of the vehicle body posture of the vehicle 1 can be avoided in advance.

  In the second embodiment described above, the presence / absence of the center of gravity of the left and right of the vehicle 1 is detected based on the yaw rate detected by the yaw rate sensor 5 or the yaw rate calculated from the difference between the left and right wheel speeds, and the center of gravity is not biased. The end timing of the anti-lock brake control of the side wheel is delayed from the side where the center of gravity is biased, but the ABS ECU 2 determines the left and right wheels from the vehicle speed detected by the wheel speed sensor 6 and the left and right wheel speeds. When a difference in road surface μ is detected between the left and right wheels immediately before the vehicle (own vehicle) 1 decelerates and stops the operation of the ABS, the ABS ECU 2 Thus, the ABS may be controlled so that the end timing of the antilock brake control of the wheel on the side with the high road surface μ is delayed from the side with the low road surface μ.

  At this time, the antilock brake control end timing of the wheel on the high road surface μ side is delayed from the low side of the road surface μ so that the antilock brake control of the low road surface wheel is set to the end vehicle speed V1. The anti-lock brake control of the wheel with the higher road surface μ is further continued while the vehicle is decelerated, and the wheel with the higher road surface μ is not locked only during the delay, so Deflection can be avoided beforehand.

1 ... Vehicle (own vehicle)
2 ... ABS ECU (detection means, control means)

Claims (2)

In a vehicle control device that performs antilock brake control for each of the left and right wheels by operating an antilock brake system in order to reduce the occurrence of sliding due to wheel locking,
Detecting means for detecting whether or not the center of gravity of the own vehicle is biased to the left and right, and whether or not there is a difference in friction coefficient between the wheels and the road surface between the left and right wheels;
Immediately before the host vehicle decelerates and stops the operation of the anti-lock brake system, if the detection means detects a deviation of the center of gravity or a difference in friction coefficient between the left and right wheels, the deviation of the center of gravity is detected. The anti-lock brake system is controlled so that the end vehicle speed at which the anti-lock brake control of a wheel having no friction or a higher friction coefficient is to be finished is lower than a side where the center of gravity is biased or a lower coefficient of friction. And a vehicle control device. In a vehicle control device that performs antilock brake control for each of the left and right wheels by operating an antilock brake system in order to reduce the occurrence of sliding due to wheel locking,
Detecting means for detecting whether or not the center of gravity of the own vehicle is biased to the left and right, and whether or not there is a difference in friction coefficient between the wheels and the road surface between the left and right wheels;
Immediately before the host vehicle decelerates and stops the operation of the anti-lock brake system, if the detection means detects a deviation of the center of gravity or a difference in friction coefficient between the left and right wheels, the deviation of the center of gravity is detected. Control means for controlling the antilock brake system so as to delay the end timing of the antilock brake control of the wheel on the non-side or high friction coefficient side from the side where the center of gravity is biased or the side where the friction coefficient is low And a vehicle control device.

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