Method and circuit arrangement for detecting motion, direction and position of a part driven by an electric motor

US6545439B2 · kind B2 · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Georg Kaeufl · Trostberg, DE
• Erwin Kessler · Bad Saulgau, DE
• Erich Liepold · Bad Birnbach, DE
• Werner Pollersbeck · Pförring, DE
• Reinhold Roedel · Reutlingen, DE
• Wolfgang Schulter · Meersburg, DE
• Klaus Spreng · Ingolstadt, DE

Key dates

• Filing date: Jul 23, 2001
• Grant date: Apr 8, 2003
• Expiry date: Jul 23, 2021

Classification

• Technology area (CPC G): Physics
• CPC primary: G01P3/489
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An electric motor for driving a component, such as a vehicle window lifter or a machine tool, functions as a generator, when the motor drive voltage is switched off and the motor is short circuited. The motor keeps running due to inertia or other influences. During this period after switch-off a generator voltage and respective generator current are produced. The generator current is measured for various purposes, preferably in combination with a measured r.p.m. signal. The generator current signal alone, or in combination with the r.p.m. signal, is evaluated to provide information regarding the motion of the driven component including information regarding the motion direction and position of the component.