Abstract In a system for controlling active suspensions of a motor vehicle, having fluid suspensions for the respective wheels, a lateral acceleration sensor, control valves for the respective suspensions, and a controller for adjusting the control valves to charge and discharge a fluid into and out of the fluid suspensions so as to control the vehicle attitude, a shut-off valve is provided between each control valve and each fluid suspension. The shut-off valve is normally open to enable the control of the vehicle attitude in an active state. When the detected lateral acceleration of the vehicle during a turn exceeds a set reference lateral acceleration, an active-passive changeover circuit delivers a shut-off signal to each shut-off valve thereby to close the shut-off valve, whereby all the fluid suspensions are sealed so that the suspension system becomes a passive state. This enables the elimination of the excessive peformance of the active suspension system and makes the suspension units smaller and less costly, reducing energy consumption.
A system for controlling active suspensions of a vehicle, having fluid suspensions provided for respective wheels, means for charging and discharging a fluid into and out of the respective fluid suspensions to extend and contract the suspensions independently, a lateral Gsensor provided in the vehicle for detecting lateral acceleration of the vehicle, and a controller responsive to an acceleration signal from the G-sensor for adjusting said charging and discharging means so as to control the amount of the fluid to be charged and discharged to maintain the vehicle attitude in a desired state, said system comprising: means for setting a reference lateral acceleration; changeover means for producing a closing signal when the detected lateral acceleration exceeds the reference lateral acceleration; and shut-off means responsive to the closing signal for sealing the fluid in the fluid suspensions to change the fluid suspensions from an active state to a passive state.
Claim 2
Independent Claim
149 words
A system for controlling active suspensions of a vehicle, having fluid suspensions provided for respective wheels, means for charging and discharging a fluid into and out of the respective fluid suspensions to extend and contract the suspensions independently, a lateral Gsensor provided in the vehicle for detecting lateral acceleration of the vehicle, and a controller responsive to an acceleration signal from the G-sensor for adjusting said charging and discharging means so as to control the amount of the fluid to be charged and discharged to maintain the vehicle attitude in a desired state, said system comprising: means for setting a reference lateral acceleration; changeover means for producing a closing signal when the detected lateral acceleration exceeds the reference lateral acceleration; and shut-off means responsive to the closing signal for sealing the fluid in the fluid suspensions to change the fluid suspensions from an active state to a passive state.
Claim 3
Dependent Claim
37 words
The system according to claim 1, wherein said shut-off means are shut-off valves installed in passages connecting said charging and discharging means to said fluid suspensions, respectively, to take a normal open position and a closed position.
Claim 4
Dependent Claim
41 words
The system according to claim 1, wherein said changeover means includes a hysteresis circuit provided to change a value of the reference lateral acceleration with a hysteresis when a shut-off valve in said shut-off mans is returned to the normal position.
Claim 5
Dependent Claim
16 words
The system according to claim 1, further comprising hysteresis means for hysteresis-processing the detected lateral acceleration.
Claim 6
Dependent Claim
19 words
The system according to claim 4, further comprising dead-zone means for processing the hysteresis-processed lateral acceleration with a dead-zone.