Welding Trajectory Detecting And Control Based On Laser Ranging

Welding trajectory detecting and control is one of kernel technology for welding automation. It is especially important for automated welding in Shipbuilding Industry, Metal Pipeline, Nuclear Power, and Pressure Vessel Industry, etc. Studies of welding trajectory detecting and control based on Laser Ranging have significant importance for improving control precision of welding trajectory, enhancement of welding quality and welding efficiency and reducing labour intensity.This paper is based on the project demand from industries. Based on need for rapid detection of welding seam and real-time control of welding trajectory, the techniques for automated welding of corrugated plate of container and butt plates welding are studied. The main contents and achievements in this paper are as follows:The techniques of welding trajectory detecting and control based on Laser Ranging for corrugated plate are studied. Through adaptive filtering of detected data, the inflexion points are detected, the welding trajectory is fitted, and then welding seam trajectory interpolation is implemented.The amplitude control of welding touch swinging and smooth transition of welding criterion are studied in the paper. The on-line quantitative control of amplitude of welding touch swinging is realized by combination of off-line fitting and prestore of fitting curve. Adjustable smooth transition of welding voltage, welding current and welding speed is realized by moving window method.Welding trajectory detecting and control system of corrugated plate of container with three degrees of freedom based on Laser Ranging is developed.The methods and techniques of real-time acquisition of butt plates welding seam information and trajectory control are proposed. Edge points of welding seam are recognized from the noisy acquisition data by adaptive filtering based on edge recognition, based on which the central feature points of welding seam are separated. Meanwhile, this paper proposes a three degree quasi-uniform B-Spline dynamical fitting method. By reading overlap shape points in batches, property of welding trajectory with whole three degree quasi-uniform B-Spline is realized. Welding trajectory detecting and control system of butt plates welding based on Laser Ranging is also developed.