Wade E Char

US Patent:

62749994, Aug 14, 2001

Filed:

Dec 16, 1999

Appl. No.:

9/464101

Inventors:

Stanley K. Fujii - Torrance CA
Scott D. Downer - Torrance CA
Wade E. Char - Gardena CA

Assignee:

General Motors Corporation - Detroit MI

International Classification:

H02P 7628

US Classification:

318807

Abstract:

An induction motor control system for use in a power steering system, comprising: a power steering induction motor coupled to a power supply and providing motive input to pressurize a hydraulic steering subsystem; a phase current sensor for sensing the phase current output by the power supply; and a power steering controller coupled to the power supply for processing a commanded frequency input, the sensed phase current, and data contained in a plurality of software lookup tables using a transfer function to adjust the motor voltage produced by the power supply to control the speed of the power steering motor.

US Patent:

63073463, Oct 23, 2001

Filed:

Apr 20, 2000

Appl. No.:

9/553843

Inventors:

Scott D. Downer - Torrance CA
Stanley K. Fujii - Torrance CA
Wade E. Char - Gardena CA

Assignee:

General Motors Corporation - Detroit MI

International Classification:

H02P 124

US Classification:

318727

Abstract:

A power steering system and induction motor load compensation algorithm or processing method for use in a vehicle. The power steering system comprises a power supply, a power steering motor, a steering subsystem, and a power steering controller coupled to the power supply. The controller processes a frequency command input corresponding to the power steering frequency requested by the steering subsystem and data contained in one or more software lookup tables to adjust the output frequency produced by the power supply to control the speed of the power steering, motor. The lookup tables are generated empirically and characterize the output power of the power supply at different system pressures over a range of motor speeds. The software lookup tables provide a power band that implements a power limiting state machine.