The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 29, 1989
Filed:
Jan. 19, 1989
Kenneth B Haefner, Schenectady, NY (US);
Bruce M Bernstein, Schenectady, NY (US);
Bernard J Carey, Schenectady, NY (US);
Kenneth J Overton, Clifton Park, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
This real time adaptive control and method of controlling a spot welding process compensates for electrode wear, oxidized surfaces, fit up variations and machine variations. Workpiece thermal growth is the measurement discriminant and the welding machine heat command is the control input. The control utilizes a least squares estimator to monitor the process and workpiece displacement, a precompensator to shape a desired displacement trajectory command, and a model reference control with a Smith-predictor to compensate for time delays and a proportional-integral-derivative compensator. The model reference control has a mathematical model of the spot welding process and calculates an estimated displacement using a predicated process gain and bias calculated by the estimator. The estimated displacement is compared to the precompensator displacement trajectory and an error is generated which regulates the heat command through the PID compensator.