Research On Hybrid Force/Position Control Technology For Grinding

Grinding is an important process to improve the surface quality of workpiece.Because the traditional manual grinding process will greatly affect the physical and mental health of workers,therefore,robot processing technology is more and more used in the field of grinding processing.Some researches show that the machining quality of workpiece surface can be improved by keeping constant normal grinding force during grinding process.Therefore,robot manpower control is an important research content in the field of robot automatic grinding.In this thesis,the constant force of industrial robot polishing system platform to explore design,based on the robot’s position feedback control,in the process of machining,by installing in the end of the robot end force sensor feedback interaction force between the tool and the workpiece surface,and then through the force/position control strategy into the end of the tool position correction,Thus,the normal contact force of the workpiece surface is kept constant,which can effectively improve the machining quality of the workpiece surface.Theoretical analysis was carried out on the grinding process,first find out the key factors affecting the quality of processing,and then in the process of grinding method to obtain contact force are analyzed,and then to end the force sensor feedback information tools and sensors to zero gravity compensation to eliminate,through experiment contrast before and after compensation,verify the effectiveness of the proposed compensation algorithm.The existing robot grinding process is studied,aiming at the problems existing in the application of the existing robot grinding,the constant force grinding control scheme of the robot is designed.Based on the force/position hybrid control strategy and impedance control strategy,combined with the adaptive control law,an adaptive hybrid impedance control strategy based on robot position is proposed,and the simulation and physical verification are carried out.The robot constant force polishing system platform is built,which can be divided into hardware system and software system.The hardware system includes industrial robot,motion controller and six-dimensional force sensor.The software system adopts modular design,including: robot kinematics module,force/position control module,logic module,visual module.Experiments are carried out on the robot constant force grinding system platform to verify the feasibility of the adaptive hybrid impedance control strategy proposed in this thesis in actual production operations.