The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 12, 1995
Filed:
Nov. 04, 1994
Kevin M McLaughlin, Troy, MI (US);
Mark W Gluch, Grosse Ile, MI (US);
TRW Inc., Lyndhurst, OH (US);
Abstract
A control arrangement for an electric assist steering system having a variable reluctance motor (26) includes sensing (54) motor position and sensing (110) applied steering torque. A controller determines a desired motor torque assist value in response to the applied steering torque. A plurality of look-up tables are provided having a plurality of motor current values versus motor position values stored therein. The stored motor current values are functionally related to motor position values. The controller selects a first (T1) and second (T2) torque look-up table from the plurality of look-up tables. The first look-up table corresponds to a torque value less than the desired motor torque assist value. The second look-up table corresponds to a torque value greater than the desired motor torque assist value. A first motor current value (I1) is determined by interpolating between two current values corresponding to two motor positions stored in the first look-up table closest to the sensed motor position. A second motor current value (I2) is determined by interpolating between two current values corresponding to two motor positions stored in the second look-up table closest to the sensed motor position. A final motor current value (ICMD) is determined by interpolating between the first and second determined motor current values. A motor control signal is provided in response to the determined final motor current value.