Patent Number: 6,167,334

Title: Method and apparatus for providing variable assist power steering

Abstract: A variable assist power steering system (10) uses vehicle speed, steering wheel rate and steering valve inlet pressure to vary the steering assist provided. A control module (30) receives vehicle speed, steering wheel rate and pressure data from sensors (24, 25, 26) and produces a control signal for a flow control valve actuator (32) that bypasses fluid flow from the pump (22) to a reservoir (36), rather than to the steering valve (20) thereby affecting steering valve pressure which controls the rack piston (16) which changes the angle of the front vehicle wheels used for steering. The control module (30) employs first and second calibration tables (38, 40) to determine the control signal that ensures adequate flow while consuming the least amount of energy.

Inventors: Liubakka; Michael Kenneth (Livonia, MI), Baraszu; Robert Charles (Dearborn, MI), Collins; Ronald Joseph (Dearborn, MI)

Assignee: Ford Global Technologies, Inc.

International Classification: B62D 6/00 (20060101); B62D 005/065 ()

Expiration Date: 12/26/2017