Arrangement for detecting jamming situations in electric drives

US6239610A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gerhard Knecht · Iffezheim, DE
• Karl-Heinrich Preis · Bühlertal, DE
• Holger Prussel · Bühlertal, DE

Key dates

• Filing date: Jul 16, 1998
• Grant date: May 29, 2001
• Expiry date: Jul 16, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02H3/38
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

In an arrangement for detecting pinching situations in electric drives, provided in particular for window and sunroof openers in motor vehicles, the voltage induced in the armature of the motor is used, the induced voltage being determined from the voltage across the motor terminals and the current flowing in the armature, in particular as the difference between the voltage across the motor terminals and the product of the armature current by the armature resistance which is obtained periodically whenever possible. The armature resistance is obtained from the voltage across the motor terminals and the blocking current of the motor, the latter being determined by extrapolation of the armature current determined at a certain point in time. The armature current is measured using a shunt resistor and optionally amplified, and the current signal obtained is averaged using a microcontroller-controlled integrator with adjustable, computed integration periods, and digitized using an analog-digital converter.