| The copper contacts and fingers of high-voltage circuit breaker always work in the high-voltage environment,residual burrs on surface of which are easy to cause point discharge in the high-voltage environment,aggravating the arc ablation of copper contacts,seriously affecting the breaking ability of the circuit breaker,causing immeasurable safety risks and economic losses.Due to the variety and complexity of copper contacts and fingers,the traditional manual deburring method is time-consuming and laborious,and the CNC machine tool is costly and complicated.Taking the burR removal of high-voltage copper contact finger as background,this thesis studies the burrs removal method based on robotic force control,and independently adjusts the robot feed rate through tangential force feedback so as to realize the constant force control system of robotic deburring on the basis of off-line programming trajectory with better surface quality and higher deburring efficiency."D-H parameter method" is introduced to simplify the robot link frames,and the homogeneous transformation matrixes of each joint of the robot are analyzed in a recursive way,so as to solve the kinematics and dynamics equations of the robot.The robotic deburring path is acquired and processed by using MELFA-Works tool kit and SolidWorks 3D modeling software,and the executable file of robot deburring off-line programming trajectory is obtained by combining the online teaching method of initial point.The forming mechanism of burrs on high-voltage copper finger are analyzed,robot edge chamfer manner is selected to remove the burrs,and the cutting force in the process of robotic deburring is decomposed into normal and tangential cutting force.Single factor experiment of cutting force is designed,so as to analyze the relationship between the feed rate of robot and the tangential cutting force as well as the normal cutting force.As a result,the tangential cutting force is selected as the main control of the cutting force,meanwhile,the control model of acting force at the end of the robot and robotic f-eed rate is set up based on the tangential constant force-velocity control strategy.In MATLAB,PID simulation of Ziegler-Nichols parameter tuning method is carried out to verify the correctness of the control modelThe robot deburring cutting force control system is designed and built,which is divided into hardware platform and software platform.The hardware platform is mainly composed of 6 DOF MITSUBISHI industrial robot and its controller,cutting force acquisition and processing module,clamping and fixing module and deburring tool system.The software part mainly includes the upper computer algorithm program and the lower computer control program,which completes the control of the lower computer through the desktop instruction input,data collection and background operation on the PC sideRobotic deburring tangential constant force control experiments are carried out.Firstly,the zero drift of the force sensor is calibrated to meet the precision requirements of robot deburring cutting force control.Under the condition of cutting depth ac=0.06 mm and spindle speed n=19574 rpm,the optimal expected value of robot deburring cutting force control is obtained as Fdt=1.245 N.Based on this,the constant tangential force control experiments of robotic deburring are carried out,and angle changes of robot' s each joint are recorded to compare the burrs removal quality of copper finger with or without cutting force control.The experimental results show that through the constant tangential force-speed burrs removal control strategy,the workpiece surface roughness Ra is controlled within the scope of 0.673 ?m to 0.758 ?m,the deburrred edges are tidy and consistent,and deburring efficiency is increased by 17.4%,the undulating concave and convex cutting marks and edge overcutting on the workpiece surface caused by tool system flutter and track tracking error are effectively overcome,the burr removal quality and processing efficiency of copper parts with poor rigidity are extremely enhanced. |
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