Trajectory Planning And Interpolation Of Welding Robot Based On Laser Sensor Guidance

As robots are widely used in industrial fields,the combination of vision sensors and robots has promoted the development of guided welding robotics.This paper focuses on the trajectory planning and interpolation of the welding robot for the accuracy and smoothness of the guided welding of industrial robots.In order to improve the trajectory accuracy and smoothness of the welding robot,this paper proposes a hybrid optimal interpolation algorithm for weld joint trajectory planning using the weld coordinates obtained by the laser sensor.The algorithm uses the conformality of Hermite interpolation and the smoothness of the cubic spline to calculate a hybrid interpolation of segmented cubic spline and segmented Hermite spline for the sampled data,and the parameters that affect the results are dynamic planned.With the optimization of accuracy index and compliance index as the goal,the accurate and smooth interpolation of welding trajectory is realized,and the accuracy and compliance of interpolation curve are improved.At the same time,to ensure the smoothness of the welding process,this paper uses the interpolated trajectory,inserts an advance offset segment and performs S-shaped velocity planning for the inserted segment to overcome the start-up vibration of the robot arm during the welding process and achieve smooth welding.On this basis,this paper uses the coordinate transformation matrix of the robot and the chi-square transformation method to model the positive kinematics of the robot by the DH method,and then calculates the inverse solution of the established positive kinematics model by the closed solution method to realize the application of trajectory interpolation and planning on the welding robot.In order to verify the application effect of the algorithm,this paper constructs the simulation experiment of robot welding guidance on MATLAB platform,and realizes the visual simulation on VREP.The experimental results show that the proposed algorithm improves the trajectory accuracy and compliance index,verifies the effect of trajectory planning on the visual simulation platform,and realizes the precise and stable welding of robot based on laser sensor guidance.This paper designs and develops the software of weld data extraction and coordinate transmission based on the laser sensor.The main contents include:(1)acquiring the image data of the weld seam through the laser sensor,introducing the OpenCV machine vision library,performing a series of pre-processing on the image of the weld seam,classifying the weld seam according to different features,and extracting the coordinate values of the weld seam through different extraction algorithms;(2)introducing the communication technology based on the TCP/IP protocol for highspeed real-time and error-free data transmission requirements A set of transmission protocol texts was designed to achieve stable transmission of coordinate points and weld seam types to the robot via TCP protocol.