US 6,259,982 B1 · Method and apparatus for controlling an active suspension system

Abstract

An apparatus for controlling a vehicle active suspension system having a plurality of actuatable hydraulic motors, each corner having a motor connecting the sprung mass with its associated unsprung mass. Each motor has an associated spool valve for connecting either of two expandable fluid chambers of said motor to a pump or reservoir. Each corner has an associated force sensor for sensing the force value between its associated unsprung mass and the sprung mass. An analog, closed force loop control circuit provides a valve control signal having a value functionally related to the difference between a sensed force value and a desired force value for a selected corner. The closed loop control circuit includes a variable gain amplifier for controlling the value of the valve control signal as a function of the frequency of variations in the difference between the sensed force value and the desired force value on the selected corner. The amplifier gain is controlled as a function of hub velocity so as to undamp a selected corner and as a function of chassis velocity so as to damp the chassis. A digital processing circuit determines a displacement error value for selected corner. The displacement error value is summed with the valve drive signal. An actuator bump stop arrangement is also provided.

Claims26

Dependent claims

An apparatus for controlling a vehicle suspension having a sprung mass and an unsprung mass, said apparatus comprising:

a plurality of actuators, each corner of the vehicle having an associated actuator operatively connecting the sprung mass with its associated unsprung mass;
means for sensing at least one operating characteristic of a selected corner;
means for providing a desired actuator drive signal in response to said at least one sensed operating characteristic for achieving a desired operating characteristic for the selected corner;
means for determining the difference between said at least one sensed operating characteristic and the desired operating characteristic for the selected corner;
control means responsive to said determined difference for providing an actuator control signal having a value functionally related to said difference, said control means having a variable gain amplifier means for outputting said actuator control signal, wherein the gain of said variable gain amplifier means is controlled in response to a frequency of variations of said determined difference;
and
actuator control means for driving said actuator in response to said actuator control signal.

4 more elements

An apparatus for controlling a vehicle active suspension system having a plurality of actuatable hydraulic motors operatively connected to the sprung mass, one motor associated with each vehicle corner and having an associated unsprung mass, a fluid pump, and a plurality of spool valves, each motor having an associated spool valve for connecting either of two expandable fluid chambers of said motor to the pump to move its associated unsprung mass relative to the sprung mass, said apparatus comprising:

a plurality of force sensing means, each corner having an associated force sensing means for sensing the force value between its associated unsprung mass and the sprung mass;
closed loop control means for determining a desired force value for a selected corner and providing a valve control signal having a value functionally related to the difference between the sensed force value on said selected corner and the desired force value on said selected corner, said closed loop control means including a variable gain amplifier for controlling the value of said valve control signal as a function of the frequency of variations in said difference between the sensed force and the desired force value on said selected corner.

A method for controlling a vehicle suspension having a sprung mass and an unsprung mass, said method comprising the steps of:

providing a plurality of actuators, each corner of the vehicle having an associated actuator operatively connecting the sprung mass with its associated unsprung mass;
sensing at least one operating characteristic of a selected corner;
providing a desired actuator drive signal in response to the at least one sensed operating characteristic for achieving a desired operating characteristic for the selected corner;
determining the difference between the at least one sensed operating characteristic and the desired operating characteristic for the selected corner;
providing an actuat or control signal having a value functionally related to said difference between the sensed operating characteristic and the desired operating characteristic multiplied times a variable gain factor, wherein the variable gain factor is selected in response to a frequency of variations of said determined difference;
and
driving said actuator in response to said actuator control signal.

4 more elements

Dependencies are inferred from the claim text.

Method and apparatus for controlling an active suspension system

Life of this patent

Method and apparatus for controlling an active suspension system

Life of this patent

Abstract

Claims26