Research On High Precision Automatic Cladding Method Based On Laser Measurement

Circulating fluidized bed boiler CFBB(Circulating fluidized bed boiler)has been used in power plants,industrial production boilers and waste incineration boilers.However,boiler water wall wear and corrosion problems restrict the development of CFBB.Due to water wall wear and corrosion problems,the alloy cladding technology on the surface of water wall appeared.During the cladding process,the tube is deformed due to thermal stress,and the deformation increases as the cladding progresses,resulting in poor cladding accuracy.To solve this problem,a high-precision cladding method based on laser measurement is proposed to improve the cladding accuracy.First,the overall design scheme of the cladding robot is analyzed and researched according to the design index and working environment.The design includes the material selection and checking of the guide rails of each axis,the selection of the motor,the design of the rotary oscillator of the cladding gun,and the design of the control box.And the composition of the control system and the design of the automatic cladding control system.The working principle and composition of the laser detection system.Provide hardware and software foundations for high-precision cladding experiments.Secondly,the feasibility analysis of the method of measuring the center of the tube by the laser sensor is carried out.To find an accurate cladding path,the center of the tube needs to be measured by a laser sensor,and then the cladding path is obtained by fitting the center of the circle.The algorithm for finding the center of the circle is to use the LSF(Least Squares Fitting)algorithm to fit the data points to get the center of the fitted circle,and perform simulation verification through different measurement of the center angle.Thirdly,when the angle measurement is small,fitting the data points with the LSF method will greatly increase the fitting error,thus introducing the CCLSF(Center Constraint Least Fitting)algorithm.And the high accuracy of the method in fitting the center of the circle is verified by the simulation under a variety of small measurement center angles.And compared with other algorithms,it shows the high precision of the algorithm.It provides an effective algorithm for high-precision cladding experiments.Then,the cladding process of the cladding robot is analyzed.First,the cladding robot is modeled by D-H,and the analysis and simulation of forward kinematics and inverse kinematics are carried out.Then,the five-fold interpolation plan is determined by comparing the three-fold interpolation plan and the five-fold interpolation plan algorithm simulation.And through a set of task points for simulation analysis,dynamic modeling and simulation of the cladding robot,and finally the controller of the cladding robot is designed,and the feasibility is proved through simulation.In the experimental part,the first experiment is a laser measurement experiment,which mainly uses the CCLSF algorithm to measure and fit the tube to verify its high accuracy,and compare it with other fitting algorithms to get the high accuracy of the algorithm.The second experiment is the water wall tube cladding experiment,which mainly uses the cladding robot and the water wall tube combined with the CCLSF algorithm to obtain a series of fitting circle center points.The cladding trajectory planned by five-time interpolation of the fitting circle center point,and the cladding robot welding gun end is cladding along the trajectory.Compared with the traditional cladding method,the effectiveness of the high-precision cladding method is obtained.