Delphi Technologies, Inc.

Michael R Lukuc

David Andrew Shal

Timothy John Juuhl

Patrick Neil Hopkins

John F Hoying

David John Barta

Vardarajan R Iyengar

Bruce A Heaston

Robin Oakley

Darin Duane Dellinger

Khaled M Jundi

Iiya Lisenker

Jesse D Jones

A temperature compensation method for controlling a damping force of a magnetorheological (MR) damper is disclosed. First, a base operating current as a function of a desired force level of a damping force of the MR damper is determined, and a temperature compensation as a function of an operating temperature of the MR damper is determined. Finally, the temperature compensation is applied to the base operating current to generate a compensated operating current as a function of the desired force level of the damping force and the operating temperature of the MR damper. To refine the compensated operating current, the temperature compensation can be determined as both a function of the operating temperature of the MR damper and a relative velocity of the MR damper.

Temperature compensation for magnetorheological fluid dampers

The invention provides a method for independent axle control of a variable force damper system by providing at least one axle velocity signal from at least one vehicle sensor. The method then applies an axle control algorithm to the at least one axle velocity signal, thus determining at least one axle damping command as a function of the axle control algorithm.

Method and system for independent axle control of a variable force damper system

An improved magnetorheological fluid damper is provided which effectively provides a smooth transition, without a sharp break in the damper force/velocity curve, between very low damping forces near zero damper velocity to higher damping forces at higher piston velocities while maintaining desirable maximum force levels. The damper includes a piston assembly, including a magnet assembly and a flow gap extending through the piston assembly to permit fluid flow between the chambers. The force/velocity optimization feature includes a groove or passage open to the flow gap, positioned in series with a part of the flow gap in a magnetic circuit generated by the magnet assembly and dimensioned/sized to permit fluid flowing the passage to experience a magnetorheological effect less than a magnetorheological effect experienced by fluid flowing through the flow gap but not through the groove. Preferably, the passage is formed in an inner annular surface of a flux ring positioned around a piston core. The passage may be a single passage or multiple passages and may be formed, for example, by a curvilinear surface, a modified rectangular surface and/or a triangular surface or combinations of surfaces.

Magnetorheological fluid damper tunable for smooth transitions

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New Carlisle, OH, United States of America

Michael R Lukuc