Gm Global Technolgoy Operations, Inc.

James G McLeish

Kenneth R Meloche

Herbert A Libkie

Harry C Buchanan, Jr

Bernard J Finn

Ming-Chih Yew

Douglas R Bach

An adaptive ride control for a wheeled vehicle having sprung and unsprung masses connected by a variable damper periodically senses, during a predetermined time period, the vertical separation between the sprung and unsprung masses and generates first and second numbers from the number of road-caused oscillations of said vertical separation and the maximum range of said vertical separation, respectively, during the predetermined time period. The control includes lookup memory apparatus effective to store damping control numbers as a function of predetermined values of said first and second numbers and uses the first and second numbers to periodically obtain damping control numbers therefrom in order to adjust the variable damper in response to sensed road conditions.

Adaptive ride control for motor vehicle

A level control system for a motor vehicle with an unsprung mass including a wheel, a sprung mass, and a shock absorber connecting the sprung and unsprung masses comprises fluid power apparatus activatable to level the sprung mass with respect to the unsprung mass, a sensor effective to generate a signal indicating the level of the sprung mass relative to the unsprung mass and apparatus responsive to the sensor to compute the difference between the total times, within a predetermined time period, spent by the level above and below a predetermined trim band and apparatus effective to compare the difference of the times with a reference comprising a predetermined percentage of the predetermined time period and activate the fluid power apparatus if the difference exceeds the reference in magnitude, whereby the system can maintain a narrow trim band while the vehicle is not moving while avoiding unnecessary corrections and cycling due to excursions above and below the trim band during vehicle movement over rough surfaces.

Automatic vehicle level control

A level control system for a wheeled motor vehicle with sprung and unsprung masses, an accessory the activation of which indicates the probability of an associated vehicle load change, fluid power apparatus activatable to level the sprung mass relative to the unsprung mass and sensor apparatus effective to periodically indicate a trim or out-of-trim level condition according to predetermined criteria further comprises apparatus defining a service mode with a time period shorter than a predetermined activation time of the fluid power apparatus which avoids overshoot in level adjustment, a cruise mode with a time period longer than the out-of-trim duration of a predetermined long highway feature and a decision mode with a time period of duration intermediate the service and cruise time period durations and longer than the period of sprung mass oscillation during vehicle movement. It further comprises logic control apparatus effective to select from the service, cruise and decision time modes for the determination of trim level condition based on the previous mode, the trim level determination in the previous period and detection of an actuation of the accessory, with the decision mode being selected upon the initiation of system operation and as an intermediate step between service and cruise modes.

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Sterling Heights, MI, United States of America

James G McLeish