SUSPENSION CONTROL APPARATUS

• US 20120053791A1
• Filed: 08/30/2011
• Published: 03/01/2012
• Est. Priority Date: 08/31/2010
• Status: Active Grant

• Current Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: HARADA, Naofumi
• Granted Patent: US 9,211,875 B2
• Time in Patent Office: Days
• US Class Current: 701/38
• CPC Class Codes: B60G 17/08 Characteristics of fluid dampers adjusting fluid dampers in general F16F9/44 - F16F9/53
• CPC Class Codes: B60G 2400/10 Acceleration; Deceleration
• CPC Class Codes: B60G 2400/102 vertical
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/106 longitudinal with regard to vehicle, e.g. braking
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60T 2260/06 Active Suspension System
• CPC Class Codes: B60T 8/4031 Pump units characterised by their construction or mounting pump units in combination with valve blocks B60T8/36

Abstract

To control a wheel load of a wheel according to a lateral acceleration of a vehicle so as to enhance stability of the vehicle, provided is a suspension control apparatus, which is configured to control a wheel-load adjusting mechanism in at least one of the following manners: the wheel load of a front wheel is increased or is made unlikely to be reduced relative to the wheel load of a rear wheel when an absolute value of the lateral acceleration of the vehicle is increasing; and the wheel load of the rear wheel is increased or is made unlikely to be reduced relative to the wheel load of the front wheel when the absolute value of the lateral acceleration of the vehicle is reducing.

Claims

1. A suspension control apparatus, comprising:

a wheel-load adjusting mechanism provided between a vehicle body and a wheel of a vehicle, and capable of adjusting a wheel load of the wheel by adjusting a force generated in a direction of a distance between the vehicle body and the wheel; and

control means for controlling the wheel-load adjusting mechanism,

wherein the control means controls the wheel-load adjusting mechanism in at least one of the following manners;

the wheel load of a front wheel is increased or is made unlikely to be reduced relative to the wheel load of a rear wheel when an absolute value of a lateral acceleration of the vehicle is increasing; and

the wheel load of the rear wheel is increased or is made unlikely to be reduced relative to the wheel load of the front wheel when the absolute value of the lateral acceleration of the vehicle is reducing.

2. A suspension control apparatus according to claim 1, wherein the wheel-load adjusting mechanism is controlled in at least one of the following manners:

the wheel loads of right and left front wheels are increased or are made unlikely to be reduced when the absolute value of the lateral acceleration of the vehicle is increasing; and

the wheel loads of right and left rear wheels are increased or are made unlikely to be reduced when the absolute value of the lateral acceleration of the vehicle is reducing.

3. A suspension control apparatus according to claim 1, wherein the wheel-load adjusting mechanism is controlled in at least one of the following manners:

the wheel loads of right and left front wheels are increased or are made unlikely to be reduced regardless of a direction of a longitudinal acceleration when the absolute value of the lateral acceleration of the vehicle is increasing; and

the wheel loads of right and left rear wheels are increased or are made unlikely to be reduced regardless of the direction of the longitudinal acceleration when the absolute value of the lateral acceleration of the vehicle is reducing.

4. A suspension control apparatus according to claim 2, wherein the wheel-load adjusting mechanism is controlled in at least one of the following manners:

the wheel loads of the right and left front wheels are increased or are made unlikely to be reduced regardless of a direction of a longitudinal acceleration when the absolute value of the lateral acceleration of the vehicle is increasing; and

the wheel loads of the right and left rear wheels are increased or are made unlikely to be reduced regardless of the direction of the longitudinal acceleration when the absolute value of the lateral acceleration of the vehicle is reducing.

5. A suspension control apparatus according to claim 1, wherein the control means is configured to change a rate of increase of the wheel load according to a magnitude of a longitudinal acceleration.

6. A suspension control apparatus according to claim 2, wherein the control means is configured to change a rate of increase of the wheel load according to a magnitude of a longitudinal acceleration.

7. A suspension control apparatus according to claim 3, wherein the control means is configured to change a rate of increase of the wheel load according to a magnitude of the longitudinal acceleration.

8. A suspension control apparatus according to claim 4, wherein the control means is configured to change a rate of increase of the wheel load according to a magnitude of the longitudinal acceleration.

9. A suspension control apparatus according to claim 1, wherein the control means increases or is unlikely to reduce the wheel load at least when the vehicle accelerates in a forward direction.

10. A suspension control apparatus according to claim 2, wherein the control means increases or is unlikely to reduce the wheel load at least when the vehicle accelerates in a forward direction.

11. A suspension control apparatus according to claim 5, wherein the control means increases or is unlikely to reduce the wheel load at least when the vehicle accelerates in a forward direction.

12. A suspension control apparatus according to claim 6, wherein the control means increases or is unlikely to reduce the wheel load at least when the vehicle accelerates in a forward direction.

13. A suspension control apparatus according to claim 1, wherein the wheel-load adjusting mechanism comprises a damping-force adjusting type shock absorber capable of adjusting a damping-force characteristic between a soft characteristic and a hard characteristic.

14. A suspension control apparatus according to claim 1, wherein the wheel-load adjusting mechanism comprises a pressure cylinder capable of adjusting the wheel load by one of feeding and discharging of a fluid to increase and reduce an internal pressure.

15. A suspension control apparatus according to claim 1, wherein the wheel-load adjusting mechanism comprises an electromagnetic active suspension.

16. A suspension control apparatus, comprising:

a wheel-load adjusting mechanism provided between a vehicle body and a wheel of a vehicle, and capable of adjusting a wheel load of the wheel by adjusting a force generated in a direction of a distance between the vehicle body and the wheel; and

control means for controlling the wheel-load adjusting mechanism,

wherein the control means controls the wheel-load adjusting mechanism in at least one of the following manners;

the wheel load of a rear wheel is reduced or is made unlikely to be increased relative to the wheel load of a front wheel when an absolute value of a lateral acceleration of the vehicle is increasing; and

the wheel load of the front wheel is reduced or is made unlikely to be increased relative to the wheel load of the rear wheel when the absolute value of the lateral acceleration of the vehicle is reducing.

17. A suspension control apparatus, comprising:

a wheel-load adjusting mechanism provided between a vehicle body and a wheel of a vehicle, and capable of adjusting a wheel load of the wheel by adjusting a force generated in a direction of a distance between the vehicle body and the wheel; and

control means for controlling the wheel-load adjusting mechanism, wherein;

the wheel-load adjusting mechanism adjusts the force generated in the direction of the distance between the vehicle body and the wheel according to a command current value; and

the control means uses a lateral acceleration A_y, a lateral jerk dA_y/dt, a front-wheel side piston acceleration a_fr, a rear-wheel side piston acceleration a_rr, tuning control gains K_FR, K_RR, I0_FR, and I0_RR, and a sign function sgn so that at least one of a front-wheel side command current value I_FR and a rear-wheel side command current value I_RR satisfies the following relations;