Apparatus for the road-surface-dependent control of shock absorbers in a vehicle suspension system

US4685698A · kind A · utility

Assignee

• Daimler-Benz AG · DE

Inventors

• Walter Klinkner · Stuttgart, DE
• Fritz Schmidt

Key dates

• Filing date: May 23, 1986
• Grant date: Aug 11, 1987
• Expiry date: May 23, 2006

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60G2600/604
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

Apparatus for controlling a vehicle suspension system includes acceleration sensors mounted on the vehicle for producing electrical signals representative of road surface undulations or irregularities, processing circuitry for processing the sensor signals to produce control signals, and a shock absorber or damper having adjustable damping characteristics. The damper preferably includes two chambers connected by a controllable bypass. One of the chambers becomes smaller during compression of the suspension system, and one becomes smaller during expansion. A controllable throttle and/or valve is provided in the bypass to adjust the damping characteristic of the absorber. The circuitry produces control signals H and w which are representative of the average height of the overall road surface undulations, and a ratio of average heights of long-wave and short-wave undulations, respectively. The circuitry further processes these signals to produce control signals F and P to control the bypass throttle and/or valve, respectively, in accordance with the following relationship: EQU P=a.sub.o +a.sub.1 H+a.sub.2 w+a.sub.3 Hw EQU F=b.sub.o +b.sub.1 H+b.sub.2 w+b.sub.3 Hw where, a.sub.o -a.sub…