Detected position correcting method

• US 5,319,443 A
• Filed: 10/16/1992
• Issued: 06/07/1994
• Est. Priority Date: 03/07/1991
• Status: Expired due to Term

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Watanabe, Atsushi, Warashina, Fumikazu, Arimatsu, Taro
• Primary Examiner(s): Evans, F. L.
• Application Number:
  US07/941,071
• Time in Patent Office: 599 Days
• Field of Search: 356/372, 356/375, 901/47
• US Class Current: 356/614
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: G05B 19/4015 going to a reference at the beginning of machine cycle, e.g. for calibration

Abstract

After a calibration process has been carried out once for a sensor with respect to a certain position, the position of an object can be detected by the sensor in any other positions, so that the object can positionally be detected in a wide range. Specifically, calibration data (CDA) (32) is produced by calibration process in a position A before a camera moves, and calibration data (CDB) (33) for the camera after it is moved is calculated based on distance data CM (12) with respect to the position and attitude of the camera (3). Then, the position of an object (30) is detected on the basis of the calibration data (CDB) (33) and image data (WDB) (31) of the object (30) imaged by the camera (3) which is in the position B.

Claims

1. A method of correcting data of an object detected by a sensor to determine a position of the object, comprising the steps of:

determining first calibration data according to a calibration process carried out between the coordinate system of a movable component and the coordinate system of a sensor mounted on said movable component;

recognizing the position and attitude of said sensor before the sensor moves, when said calibration process is carried out;

recognizing the position and attitude of said sensor after the sensor is moved by said movable component;

determining a distance by which the position and attitude of said sensor has moved, from the positions and attitudes of said sensor before and after the sensor moves;

determining second calibration data for said sensor after the sensor is moved, based on said distance and said first calibration data; and

determining the position of the object based on said second calibration data and data of the object detected by said sensor after the sensor is moved.

2. A method according to claim 1, further including the steps of correcting an imaged position of said movable component depending on the position of the movable component detected by another sensor other than said sensor mounted on said movable component, and detecting a feature point of said object with said sensor mounted on said movable component,

3. A method according to claim 1, wherein said movable component comprises a robot,

4. A method according to claim 1, wherein said sensor comprises a visual sensor,

5. A method of correcting data of an object detected by a sensor to determine a position of the object, comprising the steps of:

determining first calibration data according to a calibration process carried out between the coordinate system of a movable component and the coordinate system of a sensor mounted on said movable component;

recognizing the position and attitude of said sensor before the sensor moves, when said calibration process is carried out;

recognizing the position and attitude of said sensor after the sensor is moved by said movable component;

determining a distance by which the position and attitude of said sensor has moved, from the positions and attitudes of said sensor before and after the sensor moves;

determining a temporary position of said object based on data of the object detected by said sensor after the sensor is moved and said first calibration data; and

determining the position of the object based on said temporary position of the object and said distance.