Browse Prior Art Database

Counter Card Integrity Check for Motors Using Incremental Encoders for Position Feedback in Computer-Controlled Robotics

IP.com Disclosure Number: IPCOM000038472D
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Alewine, NJ: AUTHOR [+2]

Abstract

A technique is described whereby the integrity of counter circuitry of motors, utilizing incremental encoders for position feedback in computer-controlled robotics, is checked in real time during operation of the motors. The concept is unique in that it applies to any device which utilizes an incremental encoder for shaft positioning. Failure to provide a check of the counter circuitry could cause damage to the robot and associated mechanisms. Incremental encoders are usually used to maintain the operational position of the controlling motor. Circuitry is provided to interface between the encoder and microprocessors controlling the motor. When the system is started, the system defaults or is preset to some initial value.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 2

Counter Card Integrity Check for Motors Using Incremental Encoders for Position Feedback in Computer-Controlled Robotics

A technique is described whereby the integrity of counter circuitry of motors, utilizing incremental encoders for position feedback in computer-controlled robotics, is checked in real time during operation of the motors. The concept is unique in that it applies to any device which utilizes an incremental encoder for shaft positioning. Failure to provide a check of the counter circuitry could cause damage to the robot and associated mechanisms. Incremental encoders are usually used to maintain the operational position of the controlling motor. Circuitry is provided to interface between the encoder and microprocessors controlling the motor. When the system is started, the system defaults or is preset to some initial value. As the motor shaft rotates, "A" and "B" signals generated by the encoder are fed into the counter circuitry so as to determine the direction and distance of travel. The number of unique positions which are identified by the encoder for each motor shaft revolution is determined by the number of "lines" of the encoder and in the interpretation of the signals. In normal operation of the incremental encoder, the counter circuitry should count the same number of counts for each shaft revolution. The encoders generate a signal for each full revolution called an index pulse. The technique described herein utilizes the index pulse to verify that the correct number of counts have elapsed since the previous pulse. The counter circuitry is initially preset at the index pulse utilizing a known value. The "A" and "B" signals are logically ANDed with the index pulse to provide an interrupt to the controlling micro...