Apparatus and method for detecting damage to linear guide

Patent metadata

Field	Value
Publication number	US-10464220-B2
Application number	US-201815977261-A
Country	US
Kind code	B2
Filing date	May 11, 2018
Priority date	May 19, 2017
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

An apparatus and a method for detecting damage to a linear guide on which a robot is mounted, by using a simple configuration. The apparatus has: a length measuring sensor configured to measure a position of a predetermined portion of the robot at predetermined time intervals; a current detecting section configured to detect a current value of a drive motor for driving a slide; and a judging section such as a processor, configured to, when the measured distance between the predetermined portion of the robot and the length measuring sensor is out of a range defined by a predetermined first threshold, and when the current value of the drive motor is equal to or higher than a predetermined second threshold, judge that the linear guide has been damaged.

First claim

The invention claimed is:

1. An apparatus for detecting damage to a linear guide having a slide on which a robot is mounted and a guide rail configured to guide the slide, the apparatus comprising:
a length measuring sensor configured to measure a distance between a predetermined portion of the robot and a fixed position other than the robot;
a current detecting section configured to detect a current value of a drive motor for driving the slide; and
a judging section configured to, when the distance measured by the length measuring sensor is out of a range defined by a predetermined first threshold, and when the current value of the motor is equal to or higher than a predetermined second threshold, judge that the linear guide has been damaged.

2. The apparatus as set forth in claim 1 , further comprising a storing section configured to store the first and second thresholds.

3. The apparatus as set forth in claim 1 , wherein a length measuring direction of the length measuring sensor is perpendicular to an extending direction of the guide rail.

4. The apparatus as set forth in claim 1 , wherein the judging section is configured to output an alarm, when judging that the linear guide has been damaged.

5. A method for detecting damage to a linear guide having a slide on which a robot is mounted and a guide rail configured to guide the slide, the method comprising the steps of:
storing predetermined first and second thresholds;
measuring a distance between a predetermined portion of the robot and a fixed position other than the robot;
detecting a current value of a drive motor for driving the slide; and
judging, when the distance is out of a range defined by the first threshold, and when the current value of the motor is equal to or higher than the second threshold, that the linear guide has been damaged.

Assignees

• Fanuc Corp

Inventors

• Tanaka Akira

Classifications

• G05B2219/39024

  Calibration of manipulator · CPC title

• B25J5/02

  travelling along a guideway · CPC title

• B25J9/1692

  Calibration of manipulator · CPC title

• G05B2219/39029

  Verify if calibration position is a correct, by comparing with range in rom · CPC title

• G05B2219/39041

  Calibrate only for end position · CPC title