Active suspension system providing inhibition of vehicle body vertical oscillation, and method of operation thereof

Claim 2

For a vehicle which is equipped with a body and a plurality of wheels for running on a road surface: an active suspension system, comprising: (a) a plurality of suspension actuators, each provided to one of said plurality of vehicle wheels and producing a supporting force, variable according to control of said actuator, for supporting said vehicle body above said one vehicle wheel; (b) a means for detecting the amount of relative movement between at least a one of said vehicle wheels and the vehicle body; (c) a means for detecting the rate of relative movement between said one of said vehicle wheels and the vehicle body; and: (d) a calculation and control means, for: (d1) inputting from said relative movement detecting means and from said rate of relative movement detecting means, respectively, a signal indicative of the amount of relative movement between said one of said vehicle wheels and the vehicle body, and a signal indicative of the rate of relative movement between said one of said vehicle wheels and the vehicle body; (d2) based upon said signals, determining the vertical displacement of the road surface portion upon which said one of said vehicle wheels is running; and: (d3) when said vertical displacement of said road surface portion is within a certain stroke limit of the actuator for said one of said vehicle wheels, controlling said actuator to produce a support force for said vehicle body over said one of said vehicle wheels which is sufficient to support the appropriate load component of said vehicle body; while: (d4) when said vertical displacement of said road surface portion exceeds the stroke limit of said actuator for said one of said vehicle wheels, calculating the value corresponding to the support force for said actuator necessary to travel along said road surface portion according to its determined vertical displacement, and based thereon controlling said actuator to alter the support force for said vehicle body over said one of said vehicle wheels.

Claim 3

An active suspension system for a vehicle according to claim 1, further comprising a means for detecting the actual support force which is being provided by said actuator, wherein further said calculation and control means is for comparing the actual support force of said actuator as detected by said detection means therefor with the calculated support force, and for carrying out a feedback process to bring the difference between these two values towards zero.

Claim 4

For an active suspension system for a vehicle which is equipped with a body and a plurality of wheels for running on a road surface, comprising: (a) a plurality of suspension actuators, each provided to one of said plurality of vehicle wheels and producing a supporting force, variable according to control of said actuator, for supporting said vehicle body above said one vehicle wheel; (b) a means for detecting the amount of relative movement between at least a one of said vehicle wheels and the vehicle body; and: (c) a means for detecting the rate of relative movement between said one of said vehicle wheels and the vehicle body: a method of operation, wherein: (d1) from said relative movement detecting means and from said rate of relative movement detecting means there are respectively inputted a signal indicative of the amount of relative movement between said one of said vehicle wheels and the vehicle body, and a signal indicative of the rate of relative movement between said one of said vehicle wheels and the vehicle body; (d2) based upon said signals, the vertical displacement of the road surface portion upon which said one of said vehicle wheels is running is determined; and: (d3) when said vertical displacement of said road surface portion is within a certain stroke limit of the actuator for said one of said vehicle wheels, said actuator is controlled to produce a support force for said vehicle body over said one of said vehicle wheels which is sufficient to support the appropriate load component of said vehicle body; while: (d4) when said vertical displacement of said road surface portion exceeds the stroke limit of said actuator for said one of said vehicle wheels, the value corresponding to the support force for said actuator necessary to travel along said road surface po rtion according to its determined vertical displacement is calculated, and based thereon said actuator is controlled to alter the support force for said vehicle body over said one of said vehicle wheels.

Claim 5

For an active suspension system for a vehicle which is equipped with a body and a plurality of wheels for running on a road surface, comprising: (a) a plurality of suspension actuators, each provided to one of said plurality of vehicle wheels and producing a supporting force, variable according to control of said actuator, for supporting said vehicle body above said one vehicle wheel; (b) a means for detecting the amount of relative movement between at least a one of said vehicle wheels and the vehicle body; and: (c) a means for detecting the rate of relative movement between said one of said vehicle wheels and the vehicle body: a method of operation, wherein: (d1) from said relative movement detecting means and from said rate of relative movement detecting means there are respectively inputted a signal indicative of the amount of relative movement between said one of said vehicle wheels and the vehicle body, and a signal indicative of the rate of relative movement between said one of said vehicle wheels and the vehicle body; (d2) based upon said signals, the vertical displacement of the road surface portion upon which said one of said vehicle wheels is running is determined; and: (d3) when said vertical displacement of said road surface portion is within a certain stroke limit of the actuator for said one of said vehicle wheels, said actuator is controlled to produce a support force for said vehicle body over said one of said vehicle wheels which is sufficient to support the appropriate load component of said vehicle body; while: (d4) when said vertical displacement of said road surface portion exceeds the stroke limit of said actuator for said one of said vehicle wheels, the value corresponding to the support force for said actuator necessary to travel along said road surface po rtion according to its determined vertical displacement is calculated, and based thereon said actuator is controlled to alter the support force for said vehicle body over said one of said vehicle wheels.

Claim 6

An method of operation for an active suspension system for a vehicle according to claim 3, said active suspension system further comprising a means for detecting the actual support force which is being provided by said actuator, wherein further the actual support force of said actuator as detected by said detection means therefor is compared with the calculated support force, and a feedback process is carried out to bring the difference between these two values towards zero.