JP2008189008A - Vehicle integrated control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the traveling stability of a vehicle by integrating a vehicle stability control device for controlling distribution of a driving force to each wheel and heightening stability of the vehicle with a suspension control device for controlling a posture of a vehicle body. <P>SOLUTION: This vehicle stability control device cancels oversteering and heightens traveling stability, for example by increasing distribution of a driving force of a rear wheel 2L on the turning inside at the time of oversteering to generate a turning outward yaw moment. At that time, a control for heightening a vehicle height is executed to the rear wheel 2L, whose distribution of a driving force is increased, by the suspension control device, so as to increase a wheel load of the rear wheel 2L. Thereby, a maximum friction force between the rear wheel 2L and a road can be increased, so as to heighten a control effect by the distribution of the driving force of the vehicle stability control device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle stability control device that increases the stability of a vehicle by controlling the distribution of driving force to each wheel in accordance with the traveling state of the vehicle, and suspension control that performs vehicle attitude control in accordance with the traveling state. The present invention relates to a vehicle integrated control device that performs integrated control of the device.

  Conventionally, based on signals from various sensors such as a steering angle sensor, an acceleration sensor, and a yaw rate sensor, the driving state of the vehicle such as understeer and oversteer is calculated, and each wheel is automatically independent according to the calculated driving state. 2. Description of the Related Art A vehicle stability control device is known in which a turning force and a deceleration force are controlled by applying a braking force to the vehicle to ensure turning stability and course traceability.

  In addition, by appropriately adjusting the damping characteristics of the damping force adjusting hydraulic shock absorber attached to the suspension device of each wheel and the spring force of the suspension spring such as an air suspension device, the steering stability and riding Suspension control devices that improve comfort are known.

  When the vehicle stability control device and the suspension control device described above are combined, conventionally, during the operation of the vehicle stability control device, the damping on the extension side and the contraction side of the damping force adjustable hydraulic shock absorber for all wheels By increasing the force and the spring force, the change in the posture of the vehicle is suppressed, and the running stability is improved.

However, when the conventional vehicle stability control device is operated so that the damping force and the spring force of all the wheels are increased, the braking force of each wheel is affected. However, it merely suppresses changes in the attitude of the vehicle, and the irregular surface irregularities may cause the wheels to lift off the road surface when passing through the irregularities, so that optimal control is not necessarily performed for the actual vehicle running conditions. I cannot say that. Therefore, the applicant of the present invention, in Patent Document 1, optimally controls the damping force of each wheel damping force adjusting hydraulic shock absorber and the spring force of the suspension spring by the suspension control device with respect to the operation of the vehicle stability control device. Thus, a technique for enhancing the control effect of the vehicle stability control device is disclosed.
JP 2006-103362 A

  However, in the vehicle integrated control device described in Patent Document 1, since the vehicle is stabilized by the braking force, the vehicle speed tends to decelerate when the vehicle stability control device is operated. In some cases, the results did not improve. Therefore, the vehicle stability control device that can increase the stability of the vehicle without deceleration by controlling the driving force distribution of the left and right wheels according to the traveling state of the vehicle such as understeer and oversteer, and the above-mentioned A technique for optimally combining the suspension control device is desired.

  The present invention has been made in view of the above points, and integrates a vehicle stability control device and a suspension control device, which enhance vehicle stability by controlling the distribution of driving force to each wheel, and It is an object of the present invention to provide an integrated vehicle control device that can improve traveling performance.

In order to solve the above-described problem, the vehicle integrated control device according to the invention of claim 1 increases the distribution of driving force to the wheels on the inside of the turn during oversteering and the outside of the turn during understeering according to the running state of the vehicle. A vehicle stability control device that increases the stability of the vehicle by increasing the distribution of driving force to the wheels of the vehicle,
A suspension control device for controlling the posture of the vehicle body by adjusting the vehicle height with an actuator for each wheel according to the running state of the vehicle,
The suspension control device increases a wheel load by increasing a vehicle height with respect to a wheel whose driving force distribution is increased by the vehicle stability control device.
According to a second aspect of the present invention, there is provided the vehicle integrated control device according to the first aspect, wherein the suspension control device has a shortage of an actuator stroke for increasing a vehicle height with respect to a wheel having an increased driving force distribution. In some cases, the actuator is caused to stroke in the direction of decreasing the vehicle height by increasing the vehicle height with respect to the wheels on the diagonal side of the wheels.
According to a third aspect of the present invention, the vehicle integrated control device increases the distribution of the driving force to the wheels on the inside of the turn during oversteering, and increases the distribution of the driving force to the wheels on the outside of the turning during understeering, according to the running state of the vehicle. A vehicle stability control device that increases vehicle stability by
A suspension control device for controlling the damping force of the damping force adjusting hydraulic shock absorber for each wheel according to the running state of the vehicle,
The suspension control device reduces the damping force on the expansion side of the damping force adjusting hydraulic shock absorber and increases the damping force on the contraction side with respect to the wheels whose driving force distribution is increased by the vehicle stability control device. It is characterized by.
According to a fourth aspect of the present invention, in the vehicle integrated control device according to the third aspect, the damping force adjusting hydraulic shock absorber is a damping force reversal type.

According to the vehicle integrated control device of the first aspect of the invention, the maximum frictional force between the wheel and the road surface is increased by increasing the wheel load of the wheel whose driving force distribution is increased by the vehicle stability control device. Therefore, the control effect of the vehicle stability control device can be enhanced.
According to the vehicle integrated control device of the second aspect of the invention, it is possible to reliably execute the control for recovering the stroke of the actuator and increasing the wheel load.
According to the vehicle integrated control device of the third aspect of the invention, by increasing the damping force adjusting type hydraulic shock absorber so as to be easily extended and difficult to contract, the wheel load of the wheel whose driving force distribution is increased by the vehicle stability control device is increased. The maximum frictional force between the wheel and the road surface can be increased, and the control effect of the vehicle stability control device can be enhanced.
According to the vehicle integrated control device of the fourth aspect of the present invention, the damping force adjusting hydraulic shock absorber is of the damping force reversal type, thereby controlling the damping force of one operation stroke of the damping force adjusting hydraulic shock absorber. However, since the attenuation of the other operation stroke is also automatically controlled, the control can be simplified and response delay can be prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A first embodiment of the present invention will be described with reference to FIGS. The vehicle integrated control device according to the present embodiment includes a vehicle stability control device and a suspension control device.

  The vehicle stability control device calculates the running state of the vehicle based on signals from various sensors such as a steering angle sensor, an acceleration sensor, a yaw rate sensor, and a wheel speed sensor, and understeers (with respect to the steering angle with respect to the steering angle). The occurrence of oversteer (a state in which the vehicle tends to face inward in the turning direction with respect to the steering angle) due to a situation in which the vehicle tends to face outward in the turning direction) or a rear wheel skid. And according to the running state of the vehicle, the driving force distribution to each wheel (left and right wheels) necessary for returning the vehicle to the stable state is calculated, and based on the calculation result, the differential device and the clutch device Etc. are operated to distribute the driving force to each wheel, thereby controlling the turning moment and acceleration force of the vehicle to improve the turning stability and the course tracing property.

  At the time of oversteering, as shown in FIG. 1, the driving force distribution for the rear wheel 2L inside the turning of the vehicle 1 is increased and the driving force distribution for the rear wheel 2R outside the turning is decreased. As a result, an outward turning yaw moment can be generated in the vehicle 1, and the oversteer can be canceled and the stability of the vehicle can be improved. At this time, the driving force distribution for the front wheel 3L inside the turn may be increased and the driving force distribution for the front wheel 3R outside the turn may be decreased. In FIG. 1, an arrow indicates a turning direction (left turning).

  Further, at the time of understeer, as shown in FIG. 2, the driving force distribution to the rear wheel 2R outside the turning of the vehicle 1 is increased and the driving force distribution to the rear wheel 2L inside the turning is decreased. Thereby, the yaw moment of turning inward can be generated in the vehicle 1, and understeer can be canceled and the stability of the vehicle can be improved. At this time, the driving force distribution for the front wheel 3R outside the turn may be increased and the driving force distribution for the front wheel 3L inside the turn may be decreased. In FIG. 2, the arrow indicates the turning direction (left turning).

  In this way, by controlling the driving force distribution to the left and right wheels according to the traveling state, oversteer and understeer can be eliminated and the steering stability can be improved without decelerating the vehicle speed.

  In normal suspension control, the suspension control device is equipped with an actuator such as a hydraulic cylinder for adjusting the vehicle height and a damping force adjustment type hydraulic shock absorber for each wheel, and an acceleration sensor, throttle position sensor, brake sensor, vehicle Based on signals from various sensors such as a high sensor and a steering angle sensor, the vehicle's posture is detected by adjusting the vehicle height, damping force, and spring force for each wheel according to the driving state. In addition, it controls the vibration and improves the handling stability and ride comfort.

The vehicle integrated control device performs the above-described individual control of the vehicle stability control device and the suspension control device, and performs integrated control as follows.
For wheels whose driving force distribution has been increased by the operation of the vehicle stability control device, the suspension control device operates the actuator in the extension direction (in the direction of increasing the vehicle height) to cause wheel load (ground contact load between the wheel and the road surface). Increase. That is, at the time of oversteer, as shown in FIG. 1, the actuator is operated in the extending direction with respect to the rear wheel 2L inside the turn to increase the wheel load (note that the driving force is distributed to the front wheel 3L inside the turn). Is increased, the actuator is operated in the extending direction with respect to the front wheel 3L inside the turn to increase the wheel load). Further, at the time of understeer, as shown in FIG. 2, the actuator is operated in the extending direction with respect to the rear wheel 2R on the outer side of the turn to increase the wheel load (note that the driving force distribution is applied to the front wheel 3R on the outer side of the turn). If it is increased, the actuator is actuated in the extending direction with respect to the front wheel 3R outside the turn to increase the wheel load).

  In this way, the maximum friction between the wheel and the road surface is obtained by increasing the wheel load by operating the actuator in the extending direction by the suspension control device for the wheel whose driving force distribution is increased by the vehicle stability control device. Since the force can be increased, a large driving force can be generated without causing the wheels to idle, and a yaw moment for stabilizing the vehicle can be effectively generated.

  Here, the maximum frictional force on the road surface of the wheel is determined by the product of the friction coefficient between them and the wheel load. During turning, lateral acceleration acts on the vehicle body and the wheel load on the wheel inside the turning In particular, since the wheel load tends to be insufficient with respect to the increase in the driving force distribution in the above-described oversteer control, the effect of increasing the wheel load by the suspension control device is obtained. large.

  Next, the control algorithm of the suspension control device in the vehicle integrated control device of the present embodiment will be described with reference to the flowcharts of FIGS. Referring to FIG. 3, if it is determined in step 1 whether it is not oversteer or understeer, and if it is determined that it is not oversteer or understeer, normal suspension control is performed by the suspension control device in step 4. If it is determined that the vehicle is understeering or oversteering, a subroutine for detecting a driving force distribution by the vehicle stability control device in step 2 and calculating a command value for actuator operation for each wheel in step 3 (FIG. 4) is executed.

  Referring to FIG. 4, in this subroutine, it is determined in step 2-1 whether or not the driving stability distribution increasing control is performed for each wheel by the vehicle stability control device. If it is determined that the driving force distribution increase control is being performed, the wheel load increase command value is calculated in step 2-2, and the process returns to the main routine of FIG. If it is determined that drive force distribution increase control is not being performed, a command value for normal suspension control by the suspension control device is calculated in step 2-3.

  Referring to FIG. 3 again, in step 5, the actuator is operated based on the command value calculated in the subroutine of FIG. 4, and normal suspension control (when drive force distribution increase control is not performed) or Control for increasing the wheel load of the wheel (when increase control of driving force distribution is performed) is executed.

  In this way, by integrally controlling the vehicle stability control device and the suspension control device, it is possible to increase the wheel load of the wheel where the driving force distribution is increased, and to increase the yaw moment for stabilizing the vehicle. It can be generated effectively.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the part similar to the said 1st Embodiment, and only a different part is demonstrated in detail.

  In the first embodiment, since the wheel load is increased by operating the actuator in the extending direction, when the actuator is extended to the maximum stroke, the stroke is insufficient and cannot be further extended. The wheel load cannot be increased. Therefore, in the vehicle integrated control device according to the present embodiment, in addition to the control of the first embodiment, the stroke recovery control of the actuator is performed as follows. When the actuator of the wheel whose driving force distribution is increased extends to the maximum stroke, the actuator of the wheel on the diagonal side (the right front wheel for the left rear wheel or the left front wheel for the right rear wheel) is actuated in the extending direction. Raise the vehicle height. Thereby, the actuator of the wheel whose driving force distribution has been increased can be shortened, and the extension stroke can be recovered.

  Explaining the control at the time of oversteer as an example, as shown in FIG. 5, when the rear wheel 2L inside the turn with the increased driving force distribution is extended to the maximum stroke, it is arranged on the diagonal side. The vehicle height is raised by actuating the actuator of the front wheel 3R on the outside of the turn, that is, the actuator of the front wheel 3R in the extending direction. Thereby, the actuator of the rear wheel 2L inside the turn can be shortened, and the wheel load of the rear wheel 2L inside the turn can be increased by operating the actuator in the extending direction.

  A control algorithm of the suspension control device by the vehicle integrated control device of the present embodiment will be described with reference to the flowcharts of FIGS. 3 and 6. In the control algorithm of FIG. 3, the process proceeds to a subroutine shown in FIG. In the subroutine shown in FIG. 6, in the same manner as in the first embodiment, it is determined in step 2-1 whether or not there is an increase control of driving force distribution, and a command value for increasing wheel load is calculated in step 2-2. At -3, it is determined whether or not the actuator can stroke in the extension direction. If the stroke is possible, the process returns to the main routine of FIG. 3, and the actuator is operated in step 5 based on the command value for increasing the wheel load. If the actuator cannot make a stroke in the extension direction, in step 2-4, the command value for that wheel is set to zero, and the command value for extending the actuator on the diagonal wheel (raising the vehicle height) is calculated. Returning to the main routine of FIG. 3, the actuator is operated based on this command value to recover the extension stroke.

  Thus, even when the actuator of the wheel whose driving force distribution is increased extends to the maximum stroke, the extension stroke can be recovered and the wheel load can be increased.

  In the first and second embodiments, the actuator for adjusting the vehicle height may be an electromagnetic actuator such as an air cylinder (air spring) that operates by supplying and discharging air, a linear motor, etc., in addition to the hydraulic cylinder.

  Next, a third embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the part similar to the said 1st Embodiment, and only a different part is demonstrated in detail.

  In this embodiment, the suspension control device is equipped with a damping force adjustment type hydraulic shock absorber for each wheel, and in normal suspension control, an acceleration sensor, a throttle position sensor, a brake sensor, a vehicle height sensor, a steering angle sensor, etc. Based on the signals from the various sensors, the vehicle running state is detected, and the damping force adjustment type hydraulic shock absorber for each wheel is adjusted according to the running state to control the vehicle attitude change and vibration. Improve steering stability and ride comfort.

  And the suspension control device reduces the expansion side damping force of the damping force adjusting hydraulic shock absorber to the wheel whose driving force distribution is increased by the operation of the vehicle stability control device (extension side: software), The contraction side damping force is increased (contraction side: hard), and normal suspension control is executed for the hydraulic shock absorbers of the other wheels.

  That is, at the time of oversteering, as shown in FIG. 7, the damping force on the extension side of the damping force adjusting hydraulic shock absorber is reduced with respect to the rear wheel 2L on the inside of the turn whose driving force distribution has been increased by the vehicle stability control device. At the same time, the damping force on the extension side is increased, and normal suspension control is executed for the other wheels 2R, 3L, and 3R in which the other driving force distribution is not increased. Further, at the time of understeering, as shown in FIG. 8, the damping force on the extension side of the damping force adjusting hydraulic shock absorber is reduced with respect to the rear wheel 2R on the outside of the turn whose driving force distribution has been increased by the vehicle stability control device. At the same time, the damping force on the extension side is increased, and normal suspension control is executed for the other wheels 2L, 3L, and 3R in which the driving force distribution is not increased. 7 and 8, the arrow indicates the turning direction (left turning).

  As a result, the damping force adjustment type hydraulic shock absorber is less likely to contract and easily extend with respect to the wheel whose driving force distribution is increased, so that the wheel load increases and the maximum frictional force between the wheel and the road surface is increased. be able to. As a result, it is possible to generate a large driving force without causing the wheels to idle, and it is possible to effectively generate a yaw moment for stabilizing the vehicle.

  A control algorithm of the suspension control device by the vehicle integrated control device of the present embodiment will be described with reference to the flowcharts of FIGS. 3 and 9. In the control algorithm of FIG. 3, the process proceeds to a subroutine shown in FIG. In the subroutine shown in FIG. 6, as in the first embodiment, it is determined in step 2-1 whether or not the driving stability distribution increase control is performed by the vehicle stability control device for each wheel. If it is determined that the driving force distribution increasing control is being performed, the stroke direction of the damping force adjusting hydraulic shock absorber is determined in step 2-2. If the stroke direction is the expansion side, the command value is calculated so that the damping force is reduced in step 2-3, and if the stroke direction is the contraction side, the damping force is increased in step 2-4. If it is determined in step 2-2 that drive force distribution increase control is not being performed, a command value for normal suspension control is calculated in step 2-3. Thereafter, returning to the main routine of FIG. 3, in step 5, the damping force of the damping force adjusting hydraulic shock absorber is adjusted based on the command value calculated in the subroutine of FIG.

  In this way, by integrally controlling the vehicle stability control device and the suspension control device, it is possible to increase the wheel load of the wheel where the driving force distribution is increased, and to increase the yaw moment for stabilizing the vehicle. It can be generated effectively.

  In the present embodiment, as the damping force adjusting type hydraulic shock absorber, when the expansion side damping force is controlled to be large, the contraction side damping force is automatically controlled to be small, and when the stretching side damping force is controlled to be small, the contraction side damping force is controlled. A so-called damping force reversing type damping force adjusting hydraulic shock absorber, in which the damping force is automatically largely controlled, may be used. In this case, in the subroutine of FIG. 9, instead of executing the processing of step 2-2 to step 2-4, the expansion side damping force is controlled to be small (elongation side: soft), so that the contraction side damping force is Since the size automatically increases (shrinking side: hardware), the same result as that obtained when the processing in steps 2-2 to 2-4 is executed can be obtained. Thereby, it is not necessary to judge the expansion / contraction stroke of the damping force adjusting hydraulic shock absorber and control the damping force each time, so that the control can be simplified and the response delay of the control can be prevented.

  In the first to third embodiments, the vehicle stability control device controls the distribution of driving force for the rear wheels 2L, 2R. However, the present invention also applies to the front wheels 3L, 3R. Thus, the present invention can be similarly applied to a device that controls driving force distribution or a device that controls driving force distribution for the front and rear four wheels.

It is explanatory drawing which shows the control at the time of the oversteer of the vehicle integrated control apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the control at the time of understeering of the vehicle integrated control apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows the main routine of the control algorithm of the vehicle integrated control apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows the subroutine of the control algorithm of the vehicle integrated control apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the subroutine of the flowchart of FIG. 2 in the vehicle integrated control apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the subroutine of the control algorithm of the vehicle integrated control apparatus which concerns on 2nd Embodiment of this invention. It is explanatory drawing which shows the control at the time of the oversteer of the vehicle integrated control apparatus which concerns on 3rd Embodiment of this invention. It is explanatory drawing which shows the control at the time of understeering of the vehicle integrated control apparatus which concerns on 3rd Embodiment of this invention. It is a flowchart which shows the subroutine of the control algorithm of the vehicle integrated control apparatus which concerns on 3rd Embodiment of this invention.

Explanation of symbols

  1 Vehicle, 2L, 2R Rear wheel, 3L, 3R Front wheel

Claims (4)

Vehicle stability control that increases vehicle stability by increasing the distribution of driving force to the inner wheel during turning, and increasing the distribution of driving force to the outer wheel during understeer, depending on the vehicle's running conditions Equipment,
A suspension control device for controlling the posture of the vehicle body by adjusting the vehicle height with an actuator for each wheel according to the running state of the vehicle,
The vehicle suspension control apparatus, wherein the suspension control apparatus increases a wheel load by increasing a vehicle height with respect to a wheel whose driving force distribution is increased by the vehicle stability control apparatus. The suspension control device increases the vehicle height with respect to the wheels on the diagonal side of the wheels when the stroke of the actuator for increasing the vehicle height is insufficient with respect to the wheels with the increased driving force distribution. The vehicle integrated control device according to claim 1, wherein the actuator is stroked in a direction to lower the vehicle height. Vehicle stability control that increases vehicle stability by increasing the distribution of driving force to the inner wheel during turning, and increasing the distribution of driving force to the outer wheel during understeer, depending on the vehicle's running conditions Equipment,
A suspension control device for controlling the damping force of the damping force adjusting hydraulic shock absorber for each wheel according to the running state of the vehicle,
The suspension control device reduces the damping force on the expansion side of the damping force adjusting hydraulic shock absorber and increases the damping force on the contraction side with respect to the wheels whose driving force distribution is increased by the vehicle stability control device. An integrated vehicle control device. The vehicle integrated control device according to claim 3, wherein the damping force adjusting hydraulic shock absorber is a damping force reversal type.

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