Apparatus for determining angular position of a motor vehicle steering wheel

US5646523A · kind A · utility

Inventors

• Harry Kaiser · Heidelberg, DE
• Manfred Abendroth · Marbach am Neckar, DE

Key dates

• Filing date: Oct 23, 1995
• Grant date: Jul 8, 1997
• Expiry date: Oct 23, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/2497
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The apparatus for determination of absolute angular position of a steering wheel (w) rotatable through several revolutions includes a fine code disk(2) nonrotatably attached to the steering column (c) and provided with circumferentially distributed code elements (2',2", 2'", . . . ) and circumferentially distributed code element sensors (5) for sensing the code elements (2", 2", 2"', . . . ) to generate fine signals which repeat after each revolution of the steering wheel and are indicative of a relative steering wheel angular position during each revolution; and a coarse code disk (7) provided with at least three code tracks (A,B,C, . . . ) and at least three code track sensors (8a, 8b, 8c , . . . ) for sensing respective code tracks (A,B,C, . . . ) to generate a progressive 3-bit coded signal indicative of the absolute steering wheel angular position over the several revolutions. The apparatus also includes a gear device (11,7') for rotatably driving the coarse code disk (7) with the fine code disk(2) having a predetermined gear reduction ratio and a microcontroller (13) for logically combining and evaluating the coarse and fine signals to determine the absolute steering wheel an…