US 5,510,986 A · Method and apparatus for controlling an active suspension system

Abstract

A force actuator (11) is connected between a vehicle body (15) and each vehicle wheel (16). A position sensor (66) senses displacement between the vehicle body and each vehicle wheel and provides a position signal (67) indicative thereof. An acceleration sensor (60) senses vertical inertial acceleration of the vehicle body relative to ground at each vehicle wheel and provides an acceleration signal (61) indicative of vertical inertial acceleration of the vehicle body at each vehicle wheel. A controller (70) including a digital signal processor (80) determines a velocity signal based on each acceleration signal. The controller determines a plurality of modal forces including heave, pitch, and roll modal forces which act on the vehicle body. The plurality of modal forces vary as a function of the position and velocity signals at the vehicle wheels. A force actuator control signal (94) at each vehicle wheel is produced which varies as a function of the plurality of modal forces. A drive circuit (95) processes the force actuator signal at each wheel and applies the processed force actuator control signal (96) at each vehicle wheel to the associated force actuator.

Claims28

Dependent claims

An apparatus for controlling a force actuator connected between a vehicle body and each vehicle wheel, the vehicle having a pair of front wheels and a pair of rear wheels, said apparatus comprising:

a position sensor for sensing displacement between the vehicle body and each vehicle wheel and for providing a position signal indicative thereof;
an acceleration sensor for sensing vertical inertial acceleration of the vehicle body relative to ground at each vehicle wheel and for providing an absolute inertial acceleration signal indicative of vertical inertial acceleration of the vehicle body at each vehicle wheel;
processing means including means for determining an absolute inertial velocity signal based on each absolute inertial acceleration signal;
said processing means including means for determining a first roll moment on the rear of the vehicle and a second moment on the front of the vehicle, said first and second roll moment having a roll moment distribution parameter;
said processing means including means for processing first and second moments and said position and absolute inertial velocity signals at the vehicle wheels to provide an absolute force actuator control signal at each vehicle wheel, the absolute force actuator control signals for the rear wheels varying as a function of said position and absolute inertial velocity signals and the roll moment on the rear wheels of the vehicle, the absolute force actuator control signals for the front wheels varying as a function of said position and absolute inertial velocity signals and the roll moment on the front wheels of the vehicle;
and
means for applying said absolute force actuator control signal at each vehicle wheel to the associated force actuator to control operation of the force actuator for vehicle handling.

4 more elements

A method for controlling a vehicle suspension system having a force actuator connected between a vehicle body and each vehicle wheel, the vehicle having a pair of front wheels and a pair of rear wheels, said method comprising the steps of:

sensing displacement between the vehicle body and each vehicle wheel and providing a position signal indicative thereof;
sensing vertical inertial acceleration of the vehicle body relative to ground at each vehicle wheel and providing an absolute inertial acceleration signal indicative of vertical inertial acceleration of the vehicle body at each vehicle wheel;
determining an absolute inertial velocity signal based on each absolute inertial acceleration signal;
determining a first roll moment on the rear of the vehicle and a second roll moment on the front of the vehicle including the steps of determining roll modal forces which act on the vehicle body and which vary as a function of the position and absolute inertial velocity signals at the vehicle wheels, said first and second roll moment having a roll moment distribution parameter;
providing an absolute force actuator control signal for each vehicle wheel which varies as a function of the roll modal forces, the absolute force actuator control signals for the rear wheels varying as a function of the roll moment on the rear wheels of the vehicle, the absolute force actuator control signals for the front wheels varying as a function of the roll moment on the front wheels of the vehicle;
applying the absolute force actuator control signal for each vehicle wheel to the associated force actuator to control operation of the force actuator for vehicle handling;
and
continuously changing the roll resisting force between the front and rear of the vehicle as the absolute force actuator control signals are being applied.

5 more elements

sensing displacement between the vehicle body and each vehicle wheel and providing a position signal indicative thereof;
sensing vertical inertial acceleration of the vehicle body relative to ground at each vehicle wheel and providing an absolute inertial acceleration signal indicative of vertical inertial acceleration of the vehicle body at each vehicle wheel;
determining an absolute inertial velocity signal based on each absolute inertial acceleration signal;
determining a first roll moment on the rear of the vehicle and a second roll moment on the front of the vehicle including the steps of determining roll modal forces which act on the vehicle body and which vary as a function of the position and absolute inertial velocity signals at the vehicle wheels, said first and second roll moment having a roll moment distribution parameter, wherein said roll moment distribution parameter is determined without regard to said displacement between the vehicle body and a single vehicle wheel and without regard to said vertical acceleration for the vehicle body relative to ground at a single vehicle wheel;
providing an absolute force actuator control signal for each vehicle wheel which varies as a function of the roll modal forces, the absolute force actuator control signals for the rear wheels varying as a function of the roll moment on the rear wheels of the vehicle, the absolute force actuator control signals for the front wheels varying as a function of the roll moment on the front wheels of the vehicle;
applying the absolute force actuator control signal for each vehicle wheel to the associated force actuator to control operation of the force actuator for vehicle handling;
and
continuously changing the roll resisting force between the front and rear of the vehicle as the absolute force actuator control signals are being applied.