Method for determining a rotation angle and/or an angle differential from phase signals

US6761075B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Siegbert Steinlechner · Leonberg, DE
• Lutz Dorfmueller · Gerlingen, DE
• Axel Wenzler · Rottweil, DE
• Ralf Noltemeyer · Wernau, DE

Key dates

• Filing date: Jun 26, 2003
• Grant date: Jul 13, 2004
• Expiry date: Jun 26, 2023

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L3/12
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention proposes a method for determining a rotation angle (&PHgr;) and/or an angular difference (&dgr;) in a divided shaft (3), which has a number of phase tracks (1a, 1b, 2a, and 2b) disposed on it, which are provided with codes. Via an evaluation unit, each group of tracks (1a, 1b, 2a, and 2b) supplies a phase signal (&agr;1, &agr;2), which is respectively ambiguous with regard to a rotation of the shaft (3). The at least two phase signals (&agr;1, &agr;2) are added up in a weighted fashion to produce a signal S from which the integer portion and the non-integer portion are calculated. The non-integer portion is proportional to the angular difference (&dgr;) between the two track groups. The torque (M) is determined through multiplication with the spring rate of an interposed torque rod. The unambiguous torque (&PHgr;) is determined from the integer portion of the signal (S) and a phase value (&agr;1) or (&agr;2) with the aid of a weighted addition.