Based On The "Measurement-Modeling-Machining" Paint Repairing Robot System Research

Under the trend of the rapid development of China’s economy,China’s automobile market is also developing very rapidly,gradually transferring from rapid growth to the stage of stock.Nowadays,cars can be seen everywhere in China.Before 2021,the number of registered cars in China has reached 281 million,which shows the large automobile base in China.Under such a large automobile base,the overall output value of the automobile aftermarket continues to increase,which is especially reflected in the field of repair and spraying of automobile surface paint.To actively respond to the national call of the Made in China 2025 plan and promote the implementation of manufacturing power strategy,improve the auto surface paint repair spray automation level,the use of automation instead of manual spraying,is the future automotive repair and paint field development inevitable trend.This paper studies and designs a set of automotive intelligent repair spraying system according to a company’s automotive repair spraying operation requirements to realize the auto repair spraying operation.The main research and design contents are as follows.First,Car paint repair robot needs to face of different sizes of vehicle models,adapt to a variety of modeling surfaces and colors.This highly adaptive requirement makes the design of paint repair robot far more difficult in target tracking,path planning,motion space and other aspects far more difficult than the painting robot in the automotive manufactory.Therefore,based on the 3D point cloud reconstruction of the vehicle.First,a large amount of point cloud data are segmenting then the eight neighborhood method is used to calculate the contour of the closed surface.Finally,the grating path is generated on the surface by the slicing method,and the critical path of each surface is formed.Secondly,based on the selected hardware,multiple servo drives,motors and controllers need to be connected.This paper uses Ether CAT bus communication protocol to connect these hardware in series and realize data transmission between them.The upper computer software used in this paper is Twin Cat3 of Beefu.In Twin Cat3,the IO port is associated with the NC axis,and relevant parameters of each axis are set in the upper computer software,and individual motion debugging of each axis can be carried out.After the above operations,PLC program is written to realize the logical motion control between each axis.Twin Cat3 provides many function libraries,such as the up-down enabling function library,the motion mode function library,etc.These function libraries can be called in the PLC program to complete the field operation of each axis,so that the painting robot can realize the multi-axis linkage to complete the painting operation.Finally,according to touch-up robot and motion platform structure design and motion law,with the improved d-h parameters touch-up robot simulation model is established,through the analysis of the kinematics of robotic arm based transformation matrix of traverse joints,mechanical arm is mainly studied the motion relationship between the six axis,using inverse simulation model of motion analysis of the mechanical arm,The torsion Angle of each joint was calculated and solved according to the position of each axis.The simulation experiment was carried out in MATLAB according to the established model,and the simulation results were compared with the set trajectory to judge whether the trajectory was continuous and stable.Then the effect of the robot is tested on the set platform.Measured show that the mechanical arm change in the actual speed and position of each joint shaft are the same as the set of PLC program,so the touch-up robot can run according to the inverse kinematics analysis to solve the torsion Angle of arrival set at the end of the position,and can the system for different cars,axis of automatic control of the robot and the vector direction on arbitrary curved surface,The eight-axis axis is driven in a linkage mode to track the surface motion smoothly.The system design method can also be widely used in the robot machining of various curved surfaces.