Automatic seam tracker and real time error cumulative control system for an industrial robot

• US 4,952,772 A
• Filed: 11/16/1988
• Issued: 08/28/1990
• Est. Priority Date: 11/16/1988
• Status: Expired due to Fees

• Current Assignee: Westinghouse Electric Corporation (Paramount Global (f/k/a ViacomCBS Inc.))
• Original Assignee: Westinghouse Electric Corporation (Paramount Global (f/k/a ViacomCBS Inc.))
• Inventors: Zana, Lawrence J.
• Primary Examiner(s): Shaw, Clifford C.
• Application Number:
  US07/271,983
• Time in Patent Office: 650 Days
• Field of Search: 318/577, 219/124.34, 901/9, 901/42
• US Class Current: 219/124.34
• CPC Class Codes: B23Q 35/128 Sensing by using optical means
• CPC Class Codes: G05B 19/425 Teaching successive positions by numerical control, i.e. commands being entered to control the positioning servo of the tool head or end effector
• CPC Class Codes: G05B 2219/36417 Programmed coarse position, fine position by alignment, follow line, path adaptive
• CPC Class Codes: G05B 2219/42162 Model reference adaptive control MRAC, correction fictive-real error, position

Abstract

A control processor in a robotic system treats optically sensed locations along the seam path ahead of the tool, which are classified in relation to elapsed distances and identified in 3-D coordinates and 3-axes tool orientation, to apply in real time and under feedforward a control signal representing the error between anticipated tool position and anticipated sensed location on the path. In the process, the anticipated sensed location is obtained by interpolation between actually sensed locations. A taught path is recovered from the robot. The control processor operation is also based on elapsed distances and related to actual tool position provided by the robot.

Claims