JP2019077315A - Vehicle body attitude control device - Google Patents

Abstract

To provide a vehicle body attitude control device capable of avoiding a quick turn or a spin of an automobile by stabilizing a vehicle body attitude even if a tire bursts during travel of an automobile.SOLUTION: A vehicle body attitude control device 1 comprises suspension devices S, S, S, Sinterposed between a vehicle body B of an automobile V and front and rear, left and right wheels W, W, W, Wand capable of adjusting an attitude of the vehicle body B, a control unit 2 for controlling the suspension devices S, S, S, S, and a burst detection unit 3 for detecting a burst of a tire T of each wheel W, W, W, W. When the burst detection unit 3 detects a burst, the control unit 2 executes attitude stability control.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle body posture control device.

  If the tire on any of the front, rear, left, and right wheels is punctured while the car is running, the air pressure of the punctured tire decreases as the car continues to travel, and the load on the wheel causes the tire or the wheel in the punctured wheel to It may be damaged.

  In order to solve this problem, when a tire puncture is detected, the damping force characteristic of a shock absorber with variable damping force interposed between the vehicle body and each wheel in an automobile is changed to Vehicle suspension systems have been proposed to prevent damage.

  When the vehicle suspension system detects a tire puncture, it makes the damping force characteristic of the shock absorber corresponding to the punctured wheel soft and the damping force characteristic of the shock absorber corresponding to the non-punctured wheel hard. Alternatively, when the vehicle suspension system detects a puncture in the tire, the damping force characteristic of the shock absorber corresponding to the punctured wheel is made to be compression side soft and expansion side hard, and the damping force characteristic of the shock absorber corresponding to the non-punctured wheel The pressure side is hard and the expansion side is soft (see, for example, Patent Document 1).

  Since the vehicle suspension system changes the damping force characteristics of the shock absorber as described above, the load bearing from the vehicle body on the unpunctured wheel is increased to reduce the load bearing on the punctured wheel, and the tire and tire on the punctured wheel Prevent damage to the wheel.

JP-A-9-99723

  As described above, the conventional vehicle suspension system copes with a puncture when the tire is stepped on a sharp object while the vehicle is running, the curb stone damages the sidewall, and the air gradually escapes from the tire. it can.

  However, in the conventional vehicle suspension system, it is not assumed that the tire bursts and bursts of air from the tire. That is, when the tire bursts, the vehicle body may be largely inclined to the flat wheel side, the vehicle behavior may become unstable, and the automobile may make a sharp turn or spin, but in the conventional vehicle suspension system , Can not cope with this situation.

  Then, this invention aims at provision of the vehicle body posture control apparatus which can make a vehicle body posture stable even if a tire bursts at the time of motor vehicle travel, and can avoid sudden turning and spin of a vehicle.

  In order to achieve the above-mentioned object, the vehicle body posture control device of the present invention controls a suspension device which is interposed between a vehicle body B of a car and wheels in front, rear, left and right to adjust the posture of the vehicle body. The suspension device includes a control unit and a rupture detection unit that detects a rupture of a tire in each wheel, and when the rupture detection unit detects a rupture, the control unit executes posture stability control and a suspension device corresponding to the wheel in which the rupture is detected Is controlled so as to suppress a drop in the vehicle height immediately above, and is controlled so as not to prevent a drop in the vehicle height immediately above for the suspension device corresponding to the wheel whose burst has not been detected. The vehicle attitude control apparatus configured as described above executes attitude stability control when it detects a tire rupture, so that the sinking of the vehicle body immediately above the wheel due to the tire explosion is suppressed, and the attitude of the vehicle body is stabilized.

  Further, the vehicle body posture control device has a vehicle height adjustment device capable of raising and lowering the vehicle body by the suspension device, and the control unit raises the vehicle height right above the wheel at which burst of the tire is detected in posture stability control. The height of the vehicle may be lowered at the vehicle body immediately above the wheel at which the burst of the vehicle is not detected. Since the vehicle body posture control device configured in this way directly adjusts the height of the vehicle body, the posture of the vehicle body can be quickly adjusted to a posture that can avoid sudden turning and spin of the vehicle, so the vehicle makes a sudden turning. And spin can be effectively avoided.

  Furthermore, in the vehicle body posture control device, the suspension device has a damping force variable shock absorber, and the control unit performs bursting of the damping force of the damping force variable shock absorber corresponding to the wheel where bursting of the tire is detected in posture stabilization control. Change the damping force of the shock absorber variable shock absorber corresponding to the wheel where the tire's burst has not been detected and the wheel whose tire's burst has not been detected. You may change so that the fall of the vehicle height immediately above may not be prevented. Since the vehicle height of the vehicle body is gradually adjusted as the damping force variable shock absorber repeats expansion and contraction, the vehicle body posture control device configured in this way can avoid sudden turning and spin of the vehicle. In order to adjust the attitude of the vehicle body as described above, in the attitude stable control, the bursting of the tire is not detected because the damping force of the damping force variable shock absorber corresponding to the wheel where the bursting of the tire is detected is detected. It may be made relatively higher than the damping force of the damping force variable shock absorber corresponding to the wheel. Further, in the posture stabilization control, the control unit makes the compression-side damping force higher than the expansion-side damping force of the variable damping shock absorber corresponding to the wheel at which the tire burst is detected, and the wheel at which the tire burst is not detected The compression side damping force may be lower than the expansion side damping force of the damping force variable shock absorber corresponding to.

  In addition, the vehicle body posture control device includes a speed detection unit that detects the speed of the vehicle, and the control unit prevents posture stability control from being executed when the speed detected by the speed detection unit is less than the speed threshold. It is also good. In the vehicle body posture control device configured in this way, since the posture stability control is not performed when the speed is low and there is no fear of sudden turning or spin of the vehicle, the driver notices the rupture of the tire, so driving It is possible to prevent the person from traveling as it is.

  Furthermore, the vehicle body posture control device includes a yaw rate sensor that detects a yaw rate of the vehicle body, an acceleration sensor that detects a lateral acceleration that is a lateral acceleration of the vehicle body, and a steering device that can steer the steered wheels of the vehicle. The control unit may execute spin stabilization control by controlling the steering device based on the yaw rate and the lateral acceleration after executing the posture stabilization control when the rupture detection unit detects the rupture. In the vehicle body posture control device configured in this way, steering wheel will be steered to make it more effective to steer the steering wheel if it becomes impossible to avoid sudden turning or spin of the car only by posture stabilization control. Can be avoided.

  Further, the vehicle body posture control device includes a torque sensor that detects a steering torque input to a steering wheel that steers the steered wheels, and the control unit controls the steering direction of the steered wheels by the spin avoidance control while executing the spin avoidance control. When the steering torque in the opposite direction acts on the steering wheel, the spin avoidance control may be ended. In the vehicle body posture control device configured as described above, when the spin avoidance control instructs steering different from the driver's intention, the driver's intended steering can be prioritized. I do not get in the way.

  The rupture detection unit has a pressure sensor that detects the air pressure of the tire at each wheel, and when the amount of change in pressure detected by the pressure sensor becomes equal to or higher than the pressure threshold, the amount of change becomes equal to or higher than the pressure threshold It may be determined that the tire at the wheel corresponding to the pressure sensor that detected the pressure has burst, or it is interposed between the vehicle body and each wheel to detect the vertical relative distance between the vehicle body and each wheel It has a stroke sensor, and if the amount of change in the relative distance of only one of the relative distances among the relative distances detected by each stroke sensor exceeds the distance threshold, the relative amount of change that exceeds the distance threshold is detected It may be determined that the tire T at the wheel corresponding to the detected stroke sensor has burst.

  According to the vehicle body posture control device of the present invention, even if the tire bursts during traveling of the vehicle, the posture of the vehicle body can be stabilized, and sudden turning or spinning of the vehicle can be avoided.

1 is a model diagram of a vehicle to which a vehicle body posture control device according to an embodiment is applied. It is a control block diagram in the vehicle body attitude control device of one embodiment. FIG. 5 is a control block diagram of a first example of a rupture detection unit of the vehicle body posture control device in one embodiment. FIG. 7 is a control block diagram of a second example of the rupture detection unit of the vehicle body posture control device according to one embodiment. It is the flowchart which showed the processing procedure of the control in the vehicle body attitude control device of one embodiment.

Hereinafter, the present invention will be described based on the embodiments shown in the drawings. As shown in FIG. 1, the vehicle body posture control device 1 according to one embodiment is interposed between a vehicle body B of an automobile V and four wheels W _FR , W _FL , W _RR , and W _RL provided on the front, rear, left, and right. Suspension device S _FR , S _FL , S _RR , S _RL which can be adjusted to adjust the posture of the vehicle body B, a control unit 2 for controlling the suspension devices S _FR , S _FL , S _RR , S _RL , and each wheel W A rupture detection unit 3 for detecting the rupture of the tire T in _FR , W _FL , W _RR and W _RL is configured.

Each part will be described in detail below. As shown in FIG. 1, an automobile V includes a vehicle body B, four wheels W _FR , W _FL , W _RR , and W _RL provided on the front, rear, left and right of a vehicle body B having a tire T, a vehicle body B, and each wheel _{W FR, W FL, W RR} , the suspension device S _FR are respectively interposed between the _{W RL, S FL, S RR} , and a S _RL. Further, in the automobile V, the right and left wheels W _FR of the front of the vehicle, W _FL right and left wheels W _FR as steerable wheels, a steering wheel 4 for steering the W _FL, the right and left wheels W _FR, the W _FL can steer And a steering device 5.

Suspension devices S _FR , S _FL , S _RR , and S _RL are interposed between the vehicle body B and the wheels W _FR , W _FL , W _RR , and W _RL in this embodiment to elastically support the vehicle body B. An air spring A as a vehicle height adjustment device, and a damping force variable shock absorber D parallel to the air spring A and capable of adjusting the damping force can be provided. The suspension devices S _FR , S _FL , S _RR , and S _RL may be any devices that can adjust the attitude of the vehicle body B.

  Although the air spring A is not shown in detail, the internal pressure can be adjusted by the supply of gas from a compressor (not shown) or the discharge of gas from the inside by opening an air valve (not shown). Therefore, the air spring A as the vehicle height adjustment device can raise the height of the vehicle V if the internal pressure is high, and can decrease the height of the vehicle V if the internal pressure is low. Thus, the air spring A as the vehicle height adjustment device can adjust the posture of the vehicle body B by adjusting the vehicle height of the vehicle body B. The control unit 2 controls the drive of the compressor and the air valve to adjust the internal pressure of the air spring A to adjust the vehicle height. The vehicle height adjustment device is not limited to the air spring A, and may be configured by an apparatus capable of adjusting the vehicle height.

  Although not shown in detail, the damping force variable shock absorber D is, for example, moved into the cylinder, a piston which is inserted into the cylinder and defines an expansion side chamber and a compression side chamber which are filled with the working fluid in the cylinder. A rod which is freely inserted and connected to the piston, and a damping valve which adjusts a damping force exerted when the piston moves relative to the cylinder. Then, the control unit 2 can adjust the damping force of the damping force variable shock absorber D by controlling the damping force valve. The damping force variable shock absorber D may be any one capable of adjusting the damping force by the control of the control unit 2 and may be capable of adjusting the damping force by adjusting the damping force characteristic. Therefore, the damping force variable shock absorber D is not structurally limited as long as the damping force can be adjusted up and down, and is not restricted with respect to the working fluid. For example, it may be a shock absorber capable of adjusting the damping force by changing the magnitude of the electric field or magnetic field acting on the fluid as the electrorheological fluid or the magnetorheological fluid. The damping force variable shock absorber D becomes difficult to expand and contract when the damping force is high, and it becomes easy to expand and contract when the damping force is low. Therefore, the damping force variable shock absorber D can adjust the amount of vibration of the vehicle body B immediately above by adjusting the damping force, so that the attitude of the vehicle body B can be adjusted.

  In addition, when the damping force variable shock absorber D can also function as an actuator, the damping force variable shock absorber D may function not only as a damping force variable shock absorber but also as a vehicle height adjustment device. As an example of the case where the damping force variable shock absorber D also functions as an actuator, there are an active suspension and an electromagnetic shock absorber that can be expanded and contracted by supplying and discharging a fluid to the cylinder. The electromagnetic shock absorber exerts thrust and damping force by the power of the motor and the motor. For example, the electromagnetic shock absorber disclosed in Japanese Patent Application Laid-Open No. 2012-167757 can be used as a suspension device.

As shown in FIG. 3, the rupture detection unit 3 has four pressure sensors 31 that respectively detect the air pressure of the tire T at each of the wheels W _FR , W _FL , W _RR , and W _RL , and each pressure detected by each pressure sensor 31. A rupture determination unit 32 that determines the rupture of the tire T based on the pressure in the tire T at the wheels W _FR , W _FL , W _RR , and W _RL . The rupture determination unit 32 monitors the pressure sequentially detected by each pressure sensor 31 at a predetermined sampling cycle, and subtracts the latest value of pressure detected by each pressure sensor 31 from the value of the pressure obtained immediately before that. To determine the amount of pressure change. When the amount of change has a positive value, the internal pressure of the tire T decreases, and when the internal pressure of the tire T decreases rapidly, the value of the amount of change becomes very large. Therefore, the rupture determination unit 32 determines that the tire T that is the detection target of the pressure sensor 31 that detects the pressure whose change amount is equal to or higher than the pressure threshold value is ruptured when the change amount is equal to or higher than the pressure threshold value. . For example, when the pressure change amount of the tire T of the front left wheel W _FL of the automobile V is equal to or greater than the pressure threshold, the rupture detection unit 3 determines that the tire T of the front left wheel W _FL has ruptured and ruptures A burst signal including information that can identify the wheel W _FL is input to the control unit 2. The pressure threshold may be set to, for example, a pressure change that would be detected when the tire T bursts, but can be set to any value.

Further, when detecting the air pressure of the tire T, the rotational speed of the wheels W _FR , W _FL , W _RR , W _RL is detected instead of the pressure sensor 31, and the air pressure of the tire T is estimated from the detected rotational speed. It is also good. When the air pressure of the tire T decreases, the overall diameter of the wheels W _FR , W _FL , W _RR , and W _RL including the tire T changes. Therefore, the rupture speed of the tire T may be detected by detecting the rotation speed of the wheels W _FR , W _FL , W _RR , W _RL and estimating the air pressure of the tire T. In addition, when the air pressure of the tire T changes, the spring constant of the tire T changes, so that the resonance frequency of the wheels W _FR , W _FL , W _RR , and W _{RL in} the front-rear direction changes. Therefore, the air pressure of the tire T may be estimated from the change of the resonant frequency in the rotational speed direction by detecting the rotational speeds of the wheels _WFR , _WFL , _WRR , and _WRL .

In addition to detecting the rupture of the tire T by detecting the internal pressure of the tire T, the rupture detection unit 3 determines the relative distance between the vehicle body B and each of the wheels W _FR , W _FL , W _RR , and W _RL. It may be monitored to detect the rupture of the tire T. Specifically, as shown in FIG. 4, the rupture detection unit 3 and a stroke sensor 33 for detecting the relative distance between the vehicle body B and each of the wheels _WFR , _WFL , _WRR , and _WRL in the vertical direction. A rupture determination unit 34 that determines the rupture of the tire T based on the relative distances detected by the stroke sensors 33 may be provided. Stroke sensor 33, the vehicle body B and the wheels _{W FR, W FL, W RR} , are respectively interposed between the W _RL, the vehicle body B and the wheels _{W FR, W FL, W RR} , and W _RL Detect relative distance in the vertical direction. The rupture determination unit 34 monitors the relative distance sequentially detected by each stroke sensor 33 at a predetermined sampling cycle, and the value of the latest relative distance detected by each stroke sensor 33 is the value of the relative distance obtained immediately before that. Subtract from the value to find the amount of change in relative distance. When one tire T of the front, rear, left and right wheels ruptures, the outer diameter including the tire T in the wheel where the tire T ruptures becomes smaller than the outer diameter of the wheel where the tire T does not rupture. Therefore, the vehicle height of the vehicle body B immediately above the wheel at which the tire T bursts is lower than the vehicle height of the vehicle body B immediately above the wheel at which the tire T is not burst. From this, the rupture determination unit 34 detects the relative distance in which the change amount becomes equal to or greater than the distance threshold value when only one of the four change amounts in the relative distance is equal to or greater than the distance threshold value. It is determined that the tire T that is the detection target of the stroke sensor 33 has burst. Therefore, for example, when the amount of change in the relative distance between the vehicle body B and the front right wheel _WFR becomes equal to or greater than the distance threshold, the rupture detection unit 3 determines that the tire T of the front right wheel _WFR has burst. A rupture signal including information that can identify the ruptured wheel W _FR is input to the control unit 2. The distance threshold may be set to, for example, the amount of change in relative distance that would be detected when the tire T bursts, but can be set to any value.

As described above, the rupture detection unit 3 detects the internal pressure of the tire T by the pressure sensor 31 and also detects the pressure between the vehicle body B and the wheels W _FR , W _FL , W _RR , and W _RL by the stroke sensor 33. The relative distance can be detected to detect the rupture of the tire T based on the relative distance. The rupture detection unit 3 monitors the four pressure sensors 31, the four stroke sensors 33, the pressure detected by the pressure sensor 31, and the relative distance detected by the stroke sensor 33, and makes the same determination as described above. The rupture of the tire T may be detected by a method. As described above, when the pressure sensor 31 and the stroke sensor 33 are used in combination, the rupture detection unit 3 can accurately detect the rupture of the tire T, and even if there is a failure in either the pressure sensor 31 or the stroke sensor 33, the tire T Can detect the explosion of

  Continuing on, the vehicle body posture control device 1 of the present embodiment is provided with a speed sensor 6 as a speed detection unit that detects the speed of the vehicle V. The speed sensor 6 inputs the detected speed to the control unit 2. Further, the vehicle body posture control device 1 of the present embodiment includes the yaw rate sensor 7 attached to the vehicle body B and the acceleration sensor 8 for detecting the lateral acceleration of the vehicle body B (lateral acceleration). The yaw rate sensor 7 detects a yaw rate which is an angular velocity about an axis in the vertical direction passing through the center of gravity of the vehicle body B and inputs the detected yaw rate to the control unit 2. The acceleration sensor 8 detects an acceleration in the lateral direction which is the lateral direction of the vehicle body B, that is, a lateral acceleration, and inputs the detected acceleration to the control unit 2.

  The control unit 2 includes a posture stabilization control unit 21 and a steering control unit 22. When the posture stabilization control unit 21 receives the burst signal from the rupture detection unit 3, the posture stabilization control unit 21 executes posture stabilization control when the speed detected by the speed sensor 6 is equal to or higher than the speed threshold. The control unit 2 controls the suspension device corresponding to the wheel in which the burst of the tire T is detected in posture stability control so as to suppress the decrease in the height of the vehicle body B immediately above, and the burst of the tire T is detected. The suspension system corresponding to the non-wheel is controlled so as not to prevent the reduction of the vehicle height of the vehicle body B immediately above.

  More specifically, when the posture stability control unit 21 receives the burst signal, the posture stability control unit 21 compares the speed input from the speed sensor 6 as the speed detection unit with the speed threshold, and the detected speed is equal to or higher than the speed threshold. Perform posture stability control. The speed threshold may be set to a traveling speed at which the behavior of the vehicle V is disturbed when the tire T bursts and the driver can not control the vehicle V. Specifically, the speed threshold may be set to about 30 km / h to 40 km / h, but may be set to any value. When the traveling speed of the vehicle V is low, even if the tire T bursts or the vehicle V disturbs its behavior, the vehicle V can be stopped by the driver's braking operation before the vehicle V reaches spin or meandering. . In addition, if posture stability control is performed when the speed is low and there is no fear of sudden turning or spin of the automobile V, the driver may continue traveling without being aware of the rupture of the tire T. By not executing the attitude stable control, it is possible to prevent the driver from traveling as it is. Therefore, when the detected speed is less than the speed threshold, the posture stabilization control unit 21 according to the present embodiment does not execute the posture stabilization control even when the burst signal is received, but does not monitor the speed but does not monitor the speed independently. Posture stabilization control may be performed when a burst signal is received. Further, in the posture stability control unit 21, the velocity of the vehicle V is monitored by the rupture detection unit 3 without monitoring the velocity of the vehicle V, and the velocity is the velocity even if the rupture determination unit 32, 34 detects rupture of the tire T. The burst signal may not be output to the control unit 2 unless the threshold value is exceeded.

Hereinafter, in the attitude stabilization control, the attitude stabilization control unit 21 controls the suspension devices S _FR , S _FL , S _RR , and S _RL as follows. As an example, posture stability control will be described in the case where the tire T in the front left wheel W _FL bursts. The posture stability control unit 21 controls the suspension device _SFL corresponding to the left front wheel W _FL in which the rupture of the tire T is detected so as to suppress the decrease in the height of the vehicle body B immediately above, and the rupture is detected. The suspension devices S _FR , S _RR , and S _RL corresponding to the other wheels W _FR , W _RR , and W _RL are controlled so as not to prevent the reduction in the height of the vehicle body B immediately above.

Specifically, in the case of the present embodiment, the suspension devices _SFR , _SFL , _SRR , and _SRL are air springs A as a vehicle height adjustment device, and a damping force variable shock absorber D capable of adjusting the damping force. And the attitude stabilization control unit 21 controls the air spring A and the damping force variable shock absorber D.

The posture stability control unit 21 supplies a gas into the air spring A for the air spring A in the suspension device _SFL corresponding to the left front wheel W _FL where the tire T bursts, and the vehicle height is set to a predetermined height. Raise it. Further, the posture stability control unit 21 controls the air spring A in the suspension devices S _FR , S _RR , and S _RL corresponding to the other wheels W _FR , W _RR , and W _RL in which the tire T is not ruptured. Exhaust the gas from the inside and reduce the vehicle height to a predetermined height. If the tire T bursts and the outer diameter of the left front wheel W _FL decreases, the vehicle body B immediately above the left front wheel W _FL sinks by that amount, so the vehicle body B leans to the left front side. The vehicle V behaves to turn to the left without operating the steering wheel 4. However, when the burst of the tire T is detected, the posture stability control unit 21 controls the air spring A as the vehicle height adjustment device to adjust the vehicle height, and therefore, the depression on the left front side of the vehicle body B due to the burst of the tire T Is suppressed, the posture of the vehicle body B is stabilized, and the turning of the vehicle V to the left can be suppressed. The vehicle height adjustment amount in the attitude stable control by the attitude stable control unit 21 may be set to be optimal for the applied vehicle V.

Furthermore, the posture stability control unit 21 increases the damping force of the damping force variable shock absorber D for the damping force variable shock absorber D in the suspension device _SFL corresponding to the left front wheel W _FL where the tire T is bursting. Control. In addition, the posture stability control unit 21 determines the damping force variable shock absorber D in the suspension devices S _FR , S _RR , and S _RL corresponding to the other wheels W _FR , W _RR , and W _RL where the tire T has not burst. Control is performed to lower the damping force of the damping force variable shock absorber D. When increasing the damping force of the left front wheel W _{FL at which} the tire T is bursting while increasing the damping force of the variable shock absorber D, reducing the damping force of the other wheel at which the tire T is not bursting The decrease of the vehicle body B directly above the left front wheel W _FL is suppressed, and the decrease of the vehicle body B directly above the other wheels W _FR , W _RR , and W _RL is not impeded. Therefore, when the posture stability control unit 21 controls the damping force variable shock absorber D as described above, the inclination of the vehicle body B to the left front side can be reduced, the posture of the vehicle body B becomes stable, and the automobile V turns to the left. Can be suppressed. The damping force of the damping force variable shock absorber D corresponding to the wheel W _FL where the tire T bursts from the damping force of the damping force variable shock absorber D corresponding to the wheels W _FR , W _RR , W _RL where the tire T is not bursting Can be relatively high, the effect of stabilizing the posture of the vehicle body B can be obtained. However, the damping force of the damping force variable shock absorber D corresponding to the wheel W _FL at which the tire T bursts is made as high as possible, and corresponds to the wheels W _FR , W _RR and W _RL at which the tire T does not burst. If the damping force of the variable damping shock absorber D is set as low as possible, the attitude of the vehicle body B can be stabilized more effectively.

In the posture stabilization control, when controlling the damping force variable shock absorber D, the posture stabilization control unit 21 may perform control as follows. For the damping force variable shock absorber D in the suspension device _SFL corresponding to the left front wheel W _FL where the tire T is bursting, the posture stability control unit 21 is a damping force when the damping force variable shock absorber D contracts. Control so as to lower the damping force when the damping force variable shock absorber D is contracted. In addition, the posture stability control unit 21 determines the damping force variable shock absorber D in the suspension devices S _FR , S _RR , and S _RL corresponding to the other wheels W _FR , W _RR , and W _RL where the tire T has not burst. The damping force variable shock absorber D is controlled so as to increase the damping force when it is contracted so as to lower the damping force when the shock absorbing operation is contracted. As described above, when the posture stability control unit 21 controls, the damping force variable shock absorber D of the front left wheel W _FL becomes higher at the contraction operation time than at the extension operation time. If expansion and contraction are repeated, reduction of the height of the vehicle body B directly above the left front wheel W _FL is suppressed, and the damping force variable shock absorber D damping force of the other wheels W _FR , W _RR , W _RL is contracted. When the damping force variable shock absorber D repeats expansion and contraction, the height of the vehicle B immediately above the other wheels W _FR , W _RR , and W _RL is reduced so that the height of the vehicle B is lower. Be done. Therefore, when the posture stability control unit 21 controls the damping force variable shock absorber D as described above, the inclination of the vehicle body B to the left front side can be reduced, the posture of the vehicle body B becomes stable, and the automobile V turns to the left. Can be suppressed.

In the case where the suspension devices _SFR , _SFL , _SRR , and _{SRL of} the present embodiment are configured of a vehicle height adjustment device and a shock absorber that can not adjust the damping force, the posture stability control unit 21 performs posture stability control. The control similar to that described above may be performed only for the vehicle height adjustment device. In addition, the suspension devices _SFR , _SFL , _SRR , and _{SRL according} to the present embodiment do not have a vehicle height adjustment device, and a suspension spring formed of a coil spring or an air spring that does not have a vehicle height adjustment function; In the case of the shock absorber D, the posture stabilization control unit 21 may perform the same control as that described above only for the damping force variable shock absorber D in posture stability control.

Subsequently, the steering control unit 22 executes spin avoidance control if there is a possibility that the vehicle V falls into a spin state after the burst detection unit 3 detects the burst of the tire T and the posture stability control is executed. In the spin avoidance control, the steering control unit 22 controls the steering device 5 based on the yaw rate of the vehicle B detected by the yaw rate sensor 7 and the lateral acceleration of the vehicle B detected by the acceleration sensor 8. Specifically, the steering control unit 22 receives the burst signal and performs posture stabilization control, and then, assuming that the yaw rate is ω, the absolute value of the yaw rate | ω | is equal to or greater than the yaw rate threshold ω _ref and the lateral acceleration Assuming that α is the lateral acceleration absolute value | α | becomes equal to or greater than the lateral acceleration threshold α _ref , it is determined that the vehicle V falls into a spin state, and spin avoidance control is executed.

Incidentally, the steering control unit 22 in the vehicle body attitude control device 1 of the present embodiment, when the speed of the vehicle V is less than the threshold speed value, the absolute value of the yaw rate | omega | and with the yaw rate threshold omega _ref or horizontal The spin avoidance control is not performed even if the absolute value of the acceleration | α | becomes equal to or greater than the lateral acceleration threshold α _ref . The steering control unit 22 in the vehicle body posture control device 1 according to the present embodiment does not perform spin avoidance control because the vehicle V can be stopped safely even when the vehicle V is in the spin state when the speed of the vehicle V is low. Instead, the steering control unit 22 determines that the absolute value of the yaw rate | ω | is greater than the yaw rate threshold ω _ref and the absolute value of the lateral acceleration | α | is greater than the lateral acceleration threshold α _ref regardless of the speed. Spin avoidance control may be performed. In addition, the velocity threshold used in determining whether or not to execute attitude stabilization control may be set to a completely different value as the velocity threshold used in determining whether or not to execute spin avoidance control.

Returning back, in a state where the vehicle V spins in the direction of left turn, for example, a large lateral acceleration in the right direction acts on the vehicle body B, and a large yaw rate to the left turn is detected. In a state where the vehicle V spins, for example, in the rightward turning direction, a large lateral acceleration in the left direction with respect to the traveling direction acts on the vehicle body B, and a large yaw rate to the right turning side is detected. Therefore, when the absolute value of the yaw rate | ω | and the absolute value of the lateral acceleration | α | are large values, the automobile V falls into a spin state. Therefore, the yaw rate threshold ω _ref is set to a value smaller than the absolute value | ω | of the yaw rate detected in the spin state so that the controller 2 can execute spin avoidance control when the vehicle V is about to fall into the spin state. The lateral acceleration threshold value α _ref is smaller than the absolute value | α | of the lateral acceleration detected in the spin state.

In the spin avoidance control, the steering control unit 22 controls the steering device 5 so that both the yaw rate and the lateral acceleration approach zero. It is assumed that a large yaw rate is generated on the left turn side of the vehicle body B of the vehicle V and a large lateral acceleration to the right is generated even after the tire T is ruptured and the attitude stabilization control is performed. In this case, since the vehicle body B may spin to the left, the steering control unit 22 controls the steering device 5 to control the front left and right wheels W _FR and W _FL, which are steered wheels, to the vehicle body B. Steer in the direction of turning to the right, and apply counter-steer to suppress spin. On the contrary, it is assumed that a large yaw rate occurs to the right turning side of the vehicle body B of the automobile V and a large lateral acceleration to the left is generated even after the tire T has burst and the attitude stabilization control is performed. . In this case, since the vehicle body B may spin to the right, the steering control unit 22 controls the steering device 5 so that the front left and right wheels W _FR and W _FL, which are steered wheels, can be transmitted to the vehicle body. Steer B in the direction to turn left and countersteer to suppress spin.

Specifically, the steering control unit 22 controls the steering device 5 by determining the steering angle θ of the front left and right wheels W _FR and W _FL as steering wheels as follows. When the vehicle V stably travels straight, both the yaw rate and the lateral acceleration become zero. Therefore, as described above, the steering control unit 22 controls the steering device 5 so that both the yaw rate and the lateral acceleration approach 0, which is the target value.

Here, when the yaw rate sensor 7 outputs a positive yaw rate with respect to turning to the left of the vehicle body B, and the acceleration sensor 8 outputs a lateral acceleration facing right with respect to the traveling direction of the vehicle V as a positive value. think of. Further, the steering angle θ of the left and right front wheels W _FR and W _{FL, which} are steered wheels, has a positive value to the right turning side.
Then, when there is a possibility that the vehicle V spins to the left, the yaw rate and the lateral acceleration take positive values, and when the vehicle V may spin to the right, the yaw rate and the lateral acceleration also become negative. Take the value of

Therefore, assuming that the yaw rate is ω, the steering control unit 22 obtains a value ω × Kω obtained by multiplying the yaw rate gain Kω and a value α × obtained by multiplying the lateral acceleration α by the lateral acceleration gain Kα. The target steering angle θ ^* is obtained by adding Kα. When the target steering angle θ ^* takes a positive value, the target steering angle θ ^* instructs the steering of the left and right front wheels W _FR and W _FL, which are steered wheels, to the right. When the target steering angle θ ^* takes a negative value, the target steering angle θ ^* instructs the steering of the left and right front wheels W _FR and W _FL, which are steered wheels, to the left turning side. Then, the steering control unit 22 obtains a deviation between the target steering angle θ ^* and the steering angles θ of the current front left and right wheels W _FR and W _FL , and performs proportional integration compensation or proportional derivative integration compensation on this deviation to obtain the front side. The steering amounts of the left and right wheels W _FR and W _FL are obtained. The steering control unit 22 controls the steering device 5 to instruct the steering device 5 to steer the front left and right wheels W _FR and W _FL by the calculated steering amount. The steering control unit 22 determines that the absolute value of the yaw rate | ω | is less than the yaw rate threshold ω _ref or the absolute value of the lateral acceleration | α | is less than the lateral acceleration threshold α _ref or the speed is less than the speed threshold. , Cancel the aforementioned spin avoidance control.

  Further, the steering control unit 22 cancels the spin avoidance control so that the direction of the steering instructed by the steering control unit 22 and the direction of the steering intended by the driver are reversed while the spin avoidance control is being executed. It has become.

Specifically, the steering control unit 22 performs spin avoidance control when the steering torque in the direction opposite to the steering direction of the left and right wheels W _FR and W _FL by spin avoidance control acts on the steering wheel 4 during spin avoidance control. Finish. Therefore, the steering control unit 22 includes a torque sensor 9 that detects a steering torque input to the steering wheel 4 that steers the front left and right wheels _WFR and _WFL, which are steered wheels.

Thus, for example, the steering control unit 22, the right and left wheels W _FR of the front is a steering wheel, when the operation amount of W _FL is pointing steering to the right turning side, the torque by the torque sensor 9 detects When detecting the torque for operating the steering wheel 4 to turn the left and right wheels W _FR and W _FL to the left, the spin avoidance control is ended, and the spin avoidance control is not performed for a predetermined time. As described above, when the spin avoidance control by the steering control unit 22 is against the driver's intention, the steering control unit 22 ends the spin avoidance control, so that the driving operation of the driver is not inhibited.

  The process of the control unit 2 up to the above will be described based on the flowchart shown in FIG. The control unit 2 first determines whether a rupture signal is input from the rupture detection unit 3 (step F1). If there is no burst signal input, the control unit 2 returns and continues monitoring the presence or absence of the burst signal input. On the other hand, if it is determined that the burst signal is input, the speed input from the speed sensor 6 is compared with the speed threshold to determine whether the detected speed is equal to or higher than the speed threshold (step F2). When the detected speed is less than the speed threshold, the control unit 2 executes a process of determining whether the detected speed is equal to or higher than the speed threshold in the next control cycle. On the other hand, if it is determined that the detected speed is equal to or higher than the speed threshold, the control unit 2 executes the above-described attitude stabilization control (step F3).

Subsequently, the control unit 2 determines whether the absolute value of the yaw rate | ω | is greater than or equal to the yaw rate threshold ω _ref and the absolute value of the lateral acceleration | α | is greater than or equal to the lateral acceleration threshold α _ref (step F4). . If the absolute value of the yaw rate | ω | is less than the yaw rate threshold ω _ref or the absolute value of the lateral acceleration | α | is less than the lateral acceleration threshold α _ref , the control unit 2 executes the process of step F4 in the next control cycle. . On the other hand, if the absolute value of the yaw rate | ω | is greater than the yaw rate threshold ω _ref and the absolute value of the lateral acceleration | α | is greater than the lateral acceleration threshold α _ref , then the controller 2 determines whether the detected speed is greater than the speed threshold It is determined whether or not it is (step F5). If the detected speed is less than the speed threshold, the control unit 2 returns to step F4 and executes the process of step F4 in the next control cycle. On the other hand, when determining that the detected speed is equal to or higher than the speed threshold, the control unit 2 executes the above-described spin avoidance control (step F6).

  Subsequently, the control unit 2 determines whether or not the direction of steering by the spin avoidance control and the direction of steering by the driver's intention are opposite (step F7). If the direction of steering by the spin avoidance control and the direction of steering by the driver's intention are opposite, the process ends. When the direction of steering by spin avoidance control and the direction of steering by the driver's intention are not reverse, the process returns to step F4. As described above, when the control unit 2 executes a series of processes, the posture stable control and the spin avoidance control are executed by the control unit 2 when the conditions are satisfied.

  The respective units of the control unit 2 may be realized by an arithmetic processing unit such as a central processing unit (CPU) executing an execution program of the above-described processing, and the rupture determination units 32 and 34 of the rupture detection unit 3 May be integrated into the

As described above, the vehicle body posture control device 1 of the present invention is interposed between the vehicle body B of the automobile V and the front and rear wheels W _FR , W _FL , W _RR and W _RL so that the posture of the vehicle body B is adjustable suspension device _{S FR, S FL, S RR} , S RL and suspension system _{S FR, S FL, S RR} , the control unit 2 for controlling the S _RL, the wheels W _FR, W _FL, W _RR , W _RL and a rupture detection unit 3 for detecting the rupture of the tire T. When the rupture detection unit 3 detects a rupture, the control unit 2 executes posture stabilization control, and a suspension device corresponding to the wheel for which the rupture is detected. Is controlled so as to suppress the reduction of the vehicle height immediately above, and is controlled so as not to prevent the reduction of the vehicle height immediately above for the suspension device corresponding to the wheel whose rupture has not been detected.

  Since the vehicle attitude control apparatus 1 configured as described above executes attitude stability control when it detects the rupture of the tire T, the sinking of the vehicle B immediately above the wheel due to the burst of the tire T is suppressed, and the attitude of the vehicle B is Is stable, and it is possible to suppress sudden turning and spin of the vehicle caused by the rupture of the tire T.

Further, in the vehicle body posture control device 1 of the present embodiment, the suspension devices _SFR , _SFL , _SRR , and _SRL have a vehicle height adjustment device (air spring A) capable of raising and lowering the vehicle body B, and the control unit 2 While raising the vehicle height in the vehicle body B immediately above the wheel at which the burst of the tire T is detected in posture stability control, the vehicle height at the vehicle body B immediately above the wheel in which the burst of the tire T is not detected is lowered. Since the vehicle body posture control device 1 configured in this way directly adjusts the height of the vehicle body B, the posture of the vehicle body B can be promptly adjusted to a posture capable of avoiding sudden turning or spinning of the vehicle V. It is possible to effectively avoid sudden turning and spin of the automobile V.

Furthermore, in the vehicle body posture control device 1 of the present embodiment, the suspension devices _SFR , _SFL , _SRR , and _SRL have the damping force variable shock absorber D, and the control unit 2 bursts the tire T in posture stability control. Changes the damping force of the damping force variable shock absorber D corresponding to the detected wheel so as to suppress the reduction of the vehicle height at the vehicle body B directly above the wheel at which the burst of the tire T is detected, The damping force of the damping force variable shock absorber D corresponding to the undetected wheel is changed so as not to prevent the reduction of the height of the vehicle body B directly above the wheel where the burst of the tire T is not detected. Since the vehicle height of the vehicle body B is gradually adjusted as the damping force variable shock absorber D repeats expansion and contraction, the vehicle body posture control device 1 configured in this way can avoid sudden turning and spin of the vehicle V. In order to perform such adjustment of the posture of the vehicle body B, specifically, in the posture stabilization control, the control unit 2 performs the damping force of the damping force variable shock absorber D corresponding to the wheel in which the rupture of the tire T is detected. Should be relatively higher than the damping force of the damping force variable shock absorber D corresponding to the wheel where the burst of the tire T is not detected. Further, in the posture stabilization control, the control unit 2 makes the pressure-side damping force higher than the expansion-side damping force of the damping force variable shock absorber D corresponding to the wheel where the rupture of the tire T is detected, and the rupture of the tire T is detected. The compression side damping force may be lower than the expansion side damping force of the damping force variable shock absorber D corresponding to the non-wheel.

  Further, the vehicle body posture control device 1 according to the present embodiment includes a speed detection unit (speed sensor 6) for detecting the speed of the vehicle V, and the control unit 2 determines the speed detected by the speed detection unit (speed sensor 6). If it is less than the speed threshold, posture stabilization control is not performed. In the vehicle body posture control device 1 configured in this manner, the driver notices the rupture of the tire T because the posture stability control is not performed when the speed is low and there is no fear of sudden turning or spin of the vehicle V. Therefore, it is possible to prevent the driver from traveling as it is.

  Furthermore, in the vehicle body posture control device 1 according to the present embodiment, the yaw rate sensor 7 for detecting the yaw rate of the vehicle body B, the acceleration sensor 8 for detecting lateral acceleration which is the lateral acceleration of the vehicle body B, and steering of the vehicle V The control unit 2 controls the steering device 5 based on the yaw rate and the lateral acceleration to execute spin after the posture detection control is performed when the rupture detection unit 3 detects a rupture. Execute avoidance control. In the vehicle body posture control device 1 configured as described above, the steering wheel is steered and the sudden turning or spin of the vehicle V is performed when the situation where the sudden turning or spin of the vehicle V can not be avoided only by the posture stable control. It can be avoided more effectively.

  Further, the vehicle body posture control device 1 of the present embodiment includes the torque sensor 9 for detecting the steering torque input to the steering wheel 4 for steering the steered wheels, and the control unit 2 performs the spin avoidance during the spin avoidance control. When the steering torque in the direction opposite to the steering direction of the steered wheels by the avoidance control acts on the steering wheel 4, the spin avoidance control is ended. In the vehicle body posture control device 1 configured as described above, when the spin avoidance control instructs a steering different from the driver's intention, the driver's intended steering can be prioritized. I do not get in the way of

Additionally, rupture detection unit 3, the wheels _{W FR, W FL, W RR} , has a pressure sensor 31 for detecting the air pressure of the tire T in W _RL, the amount of change in the pressure value detected by the pressure sensor 31 the pressure If it becomes more than the threshold value, it may be determined that the tire T in the wheel corresponding to the pressure sensor 31 which detects the pressure whose change amount becomes more than the pressure threshold value bursts, the vehicle body B and each wheel W _FR , W _FL , W _RR , and W _RL, and has a stroke sensor 33 for detecting the relative distance between the vehicle body B and each of the wheels W _FR , W _FL , W _RR , and W _RL in the vertical direction. Of the relative distances detected by the sensor 33, when the amount of change in the relative distance of only one of the relative distances exceeds the distance threshold, this corresponds to the stroke sensor 33 detecting the relative distance in which the amount of change exceeds the distance threshold. The tire T at the wheel bursts It may be determined that was.

  While the preferred embodiments of the present invention have been described above in detail, modifications, variations and changes are possible without departing from the scope of the claims.

Reference Signs List 1 vehicle body posture control device 2 control unit 3 burst detection unit 4 steering wheel 5 steering device 6 speed sensor (speed detection unit) 7 ... yaw rate sensor, 8 ... acceleration sensor, 9 ... torque sensor, A ... air spring (level control system), D ... variable damping force damper, S _FR, S _FL, S _RR , S _RL ... suspension device, T ... tire, V · · · car, W _FR , W _FL , W _RR , W _RL ... wheel

Claims (10)

A suspension device interposed between a vehicle body of the vehicle and the front, rear, left, and right wheels of the vehicle to adjust the attitude of the vehicle;
A control unit that controls the suspension device;
And a burst detection unit for detecting a tire burst at each of the wheels.
The control unit executes posture stabilization control when the rupture detection unit detects a rupture, and controls the suspension device corresponding to the wheel in which the rupture is detected so as to suppress a drop in vehicle height immediately above, and ruptures. A vehicle body posture control device, wherein the suspension device corresponding to a wheel not detected is controlled so as not to prevent a decrease in vehicle height immediately above. The suspension device has a vehicle height adjustment device capable of raising and lowering the vehicle body,
The control unit, in the posture stabilization control, raises a vehicle height immediately above a wheel at which a tire burst is detected, and lowers a vehicle height immediately above a wheel at which a tire burst is not detected. Vehicle attitude control system. The suspension device has a damping force variable shock absorber.
The control unit, in the posture stabilization control, suppresses the decrease in height of the vehicle immediately above the wheel at which the burst of the tire is detected, with the damping force of the damping force variable shock absorber corresponding to the wheel at which the burst of the tire is detected. Change the damping force of the variable damping shock absorber corresponding to the wheel where tire burst is not detected so as not to prevent the reduction of the vehicle height directly above the wheel where tire burst is not detected The vehicle body posture control device according to claim 1 or 2, characterized in that: The control unit, in the posture stabilization control, the damping force of the damping force variable shock absorber corresponding to a wheel where a tire burst is detected corresponds to the damping force variable shock absorber corresponding to a wheel where a tire burst is not detected The vehicle body posture control device according to claim 3, wherein the vehicle body posture control device is relatively higher than the damping force of the vehicle. In the posture stabilization control, the control unit makes the compression-side damping force higher than the expansion-side damping force of the damping force variable shock absorber corresponding to the wheel where burst of the tire is detected, and burst of the tire is not detected. 4. The vehicle body posture control device according to claim 3, wherein the compression side damping force is lower than the expansion side damping force of the damping force variable shock absorber corresponding to a wheel. A speed detection unit for detecting the speed of the vehicle;
The vehicle body posture according to any one of claims 1 to 5, wherein the control unit does not execute the posture stabilization control when the speed detected by the speed detection unit is less than a speed threshold. Control device. A yaw rate sensor that detects a yaw rate of the vehicle body;
An acceleration sensor that detects a lateral acceleration that is a lateral acceleration of the vehicle body;
And a steering device capable of steering the steered wheels of the vehicle.
When the rupture detection unit detects a rupture, the control unit executes attitude stabilization control, and then controls the steering device based on the yaw rate and the lateral acceleration to execute spin avoidance control. The vehicle body posture control device according to any one of claims 1 to 6. A torque sensor for detecting a steering torque input to a steering wheel for steering the steered wheels;
The control unit ends the spin avoidance control when a steering torque in a direction opposite to the steering direction of the steered wheels by the spin avoidance control acts on the steering wheel during the spin avoidance control. The vehicle body posture control device according to claim 7. The rupture detection unit has a pressure sensor that detects the air pressure of the tire at each of the wheels, and when the amount of change in pressure detected by the pressure sensor becomes equal to or higher than the pressure threshold, the amount of change becomes equal to or higher than the pressure threshold The vehicle attitude control device according to any one of claims 1 to 8, wherein it is determined that a tire at a wheel corresponding to the pressure sensor that has detected the pressure has ruptured. The rupture detection unit includes a stroke sensor interposed between the vehicle body and each of the wheels to detect a relative distance between the vehicle and the wheels in the vertical direction, and the relativeness detected by each of the stroke sensors When the amount of change in the relative distance of only one of the relative distances out of the distance exceeds the distance threshold, the tire at the wheel corresponding to the stroke sensor that detects the relative distance at which the amount of change exceeds the distance threshold The vehicle body posture control device according to any one of claims 1 to 9, wherein it is determined that the vehicle is in motion.

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