A Research Of Weld Tracking Technology Based On The Edge Effect Of The Capacitive Sensor

At present our country most of the welding operation is still in the stage of thetraditional manual welding, semiautomatic welding, there is a welding environment ispoor, wasted labor, low welding quality shortcomings, especially for large structuresduring mass production, Low level of automation of welding is particularly evidentshortcomings. There is an urgent need for automation and intelligent welding process;To achieve automation and intelligent is the most key of sensor technology, it is theeyes of the entire automatic welding system.In this paper, the beginning of the research background and significance of thetopic were introduced; then describe in detail the research status and application ofcapacitive sensors, found that the capacitive sensor technology applied in the coretechnology in the field of seam tracking is not yet mature, there are still a lot ofdefects. Based on these the paper puts forward a new type of the edge effect ofcapacitive seam tracking sensor. Concrete research content is as follows:（1） Describes the basic principles of the edge effect capacitive sensors seamtracking，seam tracking features, etc., and also expounds the composition of capacitiveseam tracking system, mainly aims at the probe structure of capacitance sensor, signalacquisition and processing circuit, microcomputer control system, and cross carriagesystem and so on are introduced;（2）Design a parallel plate capacitance sensor is different from general andapplicable to real time seam tracking the edge effect of capacitive sensor probestructure; and using Unigraphics NX draw a3D map of the sensor; using Ansys finiteelement analysis software, the establishment of a three-dimensional model of thesensor; Analysis of the sensor structure parameters are optimized, the output of thesensor characteristics, determine suitable for seam tracking of the capacitive sensorstructure parameters;（3）Put forward a new kind of linear fitting method, Determine the use of bestuniform approximation method of linearity error minimum out of line, and the abilityto meet the output characteristics of the sensor, the sensor output signal linearity isgood. And further validate the feasibility of electrodes around each type of seamtracking sensor used in the same plane capacitance seam tracking for seam trackingfields to provide a new and reliable technology; （4）The analysis for collection of edge effects for seam tracking capacitivesensor signal characteristic, proposed a compromise thresholding method based onnonlinear wavelet transform threshold method, and use it for the actual welding seamtracking of the noise reduction process;（5）Through the experiment found that the optimal general threshold denoisingeffect is not ideal, layered threshold is presented in this paper, by using particle swarmoptimization to take a different optimal threshold for wavelet thresholding eachdecomposition scale, can effectively avoid noise variance calculation with noisesignal;（6）Through the analysis of different extraction methods weld deviation, putforward a new weld deviation extraction: hybrid interval comparison method; and themethod used in new type edge effect capacitance extraction on seam tracking sensordeviation in theory research;...