A suspension system for a vehicle has shock absorbers, each provided so as to be associated with one wheel and between sprung parts and unsprung parts, step motors, each being adapted for changing damping force characteristics of one of the shock absorbers by open loop control, and a controller for outputting control signals to the step motors. The controller is adapted for outputting control signals every predetermined time interval so as to make the damping force characteristics of the shock absorbers harder. According to the thus constituted suspension system for a vehicle, it is possible to prevent the driving stability from being lowered even when at least one of the step motors is thrown out of synchronism.

A vehicle height control apparatus for a vehicle is comprised of a fluid chamber installed for each wheel. The fluid chamber changes the vehicle height by receiving or discharging the fluid supplied from a fluid supply source. The vehicle height control apparatus operates to decrease the difference between right and left vehicle heights when the difference between the right and left vehicle heights is greater than a predetermined value, the vehicle is in a parked condition, and the fluid supply source cannot supply the fluid to the fluid chamber. The operation by the apparatus is carried out such that the right and left fluid chambers are communicated with each other.

A system for dynamically determining an operating state of a motor vehicle for input to a controller employed to control dynamics of the motor vehicle includes sensors for measuring predetermined vehicle operating state. The system also includes a device for predicting a value for the predetermined operating state, which can then be used to determine a correction factor for the measured operating state signal. This correction factor is proportional to the erroneous component of the measured vehicle operating state. Together, measured operating state and the correction signal are used to obtain a compensated operating state signal. This is particularly useful for reducing the effects of sensor drift and DC offset.

An actively controlled suspension system comprises a hydraulic cylinder disposed between a vehicle body and a suspension member rotatably supporting a vehicular wheel, the hydraulic cylinder defining therein a working chamber, a pressure source including a pump associated with an automotive internal combustion engine to be driven by the output of the engine, a pressure control valve having a first port connected to the working chamber, a second port connected to the pressure source via a supply line and a third port connected to the pressure source via a drain line, the pressure control valve being variable of valve position for selectively establishing and blocking fluid communication between the first port and the second port and between the first port and the third port for adjusting fluid pressure in the working chamber for controlling suspension characteristics, a vertical acceleration sensor for monitoring vertical acceleration exerted on the vehicular body to produce a vertical acceleration indicative signal, first circuit for arithmetically deriving a vertical stroke speed of the vehicular body on the basis of the vertical acceleration indicative signal, second circuit for detecting initiation of arithmetic operation of the first circuit for setting data for use in derivation of the vertical speed in a value for cancelling offset contained in the vertical acceleration indicative signal.

A method of correcting drift in a sensor includes the step of identifying a calibration command. A nominal zero pressure sensor drift correction factor for the sensor is identified by relying upon a calibration voltage value and a calibration temperature value secured at a nominal zero pressure condition. Sensor output is subsequently adjusted according to the nominal zero pressure sensor drift correction factor.