Encoder wheel assembly and method for ascertaining an absolute angular position and a rotational direction

US11293785B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Fabian Utermoehlen · Lippstadt, DE
• Bernd Eckert · Lambach, DE
• Marcel Maur · Gerlingen, DE
• Matthias Letzgus · Ellwangen (Jagst), DE
• Stephan Hanel · Markgröningen, DE
• Tino Merkel · Schwieberdingen, DE

Key dates

• Filing date: Nov 20, 2017
• Grant date: Apr 5, 2022
• Expiry date: Aug 1, 2038

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D2205/85
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An encoder wheel assembly comprising: a first encoder wheel rotationally fixed to a rotor and having a number n of teeth arranged along the circumference of the encoder wheel; a second encoder wheel rotationally fixed to the first encoder wheel, and having the same number n of teeth as the first encoder wheel along the circumference of the encoder wheel, wherein the teeth of the second encoder wheel have an asymmetrical angular offset relative to the teeth of the first encoder wheel; a first sensor designed to scan the first encoder wheel; a second sensor designed to scan the second encoder wheel; and a controller connected to the first sensor and the second sensor and designed to ascertain the absolute angular position and the rotational direction based on a binary signal derived from a first signal of the first sensor and a second signal of the second sensor.