Optoelectronic position detection system and method of position determination

Patent metadata

Field	Value
Publication number	US-2018195882-A1
Application number	US-201815867291-A
Country	US
Kind code	A1
Filing date	Jan 10, 2018
Priority date	Jan 12, 2017
Publication date	Jul 12, 2018
Grant date	—

Abstract

The invention relates to an optoelectronic position detection system for position determination having a positioning scale with position marks and a sensor apparatus with two sensor units each consisting of a light receiver for generating received signals from received light that was reflected by the position marks and each having an evaluation unit for evaluating the received signals and outputting the evaluation results. To provide a position detection system that works more robustly and more reliably and that in particular satisfies the functional safety such as is demanded by the relevant safety standards, it is proposed that the sensor units are configured as identical. The invention further relates to a method for failsafe position determination in which position marks on a positioning scale are detected by an optoelectronic position detection system.

First claim

1 . An optoelectronic position detection system for position determination, the optoelectronic position detection system comprising:
a positioning scale with position marks; and a sensor apparatus with two sensor units each consisting of a light receiver for generating received signals from received light that was reflected by the position marks and each having an evaluation unit for evaluating the received signals and outputting the evaluation results, wherein the sensor units are configured as identical; and wherein the sensor units are arranged in a fixed spatial relationship and at a spacing from one another such that a first one of the two sensor units always detects at least two position marks and the second one of the sensor units always detects three different position marks; and wherein the evaluation results are supplied to a safety control in which a piece of failsafe position information is generated from the evaluation results.

2 . The system in accordance with claim 1 , wherein the sensor units are tilted with respect to one another such that the position marks are seen at different angles of view by the sensor units.

3 . The system in accordance with claim 1 , wherein the sensor units are installed on a common holder.

4 . The system in accordance with claim 1 , wherein the evaluation results are position results; and wherein the control unit checks the two positions determined for plausibility.

5 . A method for failsafe position determination in which position marks on a positioning scale are detected by an optoelectronic position detection system comprising:
a positioning scale with position marks; and a sensor apparatus with two sensor units each consisting of a light receiver for generating received signals from received light that was reflected by the position marks and each having an evaluation unit for evaluating the received signals and outputting the evaluation results, wherein the sensor units are configured as identical; and wherein the sensor units are arranged in a fixed spatial relationship and at a spacing from one another such that a first one of the two sensor units always detects at least two position marks and the second one of the sensor units always detects three different position marks; and wherein the evaluation results are supplied to a safety control in which a piece of failsafe position information is generated from the evaluation results, and in which method position information coded in the position marks is read out and the position information with respect to a failsafe position indication is processed in the safety control, with the safety control checking whether the position information with respect to the spatial spacing of the sensor units is plausible.

Assignees

• Sick Ag

Inventors

• Fehrenbach Thomas
• Tschuch Sebastian
• Fischer Martin
• Ams Mathias
• Schwörer Stefan

Classifications

• G01D5/34715 Primary

  Scale reading or illumination devices · CPC title

• G01D5/34792 Primary

  with only digital scales or both digital and incremental scales · CPC title

• G01D5/24461

  by redundancy or plausibility · CPC title