Study On The Precision And Automatic Drilling System Of Multi-joint Industrial Robots For Complex Surfaces

The precision and automatic drilling process of multi-joint industrial robots for complex surfaces is a process of drilling for complex surfaces parts by controlling the movement of the multi-joint industrial robot.The precision and automatic drilling technology of multi-joint industrial robots for complex surfaces started relatively late in China.The technical research in this area is still in its infancy,and the application in foreign countries in this technical field has been mature.It will help fill the gaps in domestic technology and accelerate the development of catching up with mature foreign technology countries.It is of great significance to the development of manufacturing technology in China.In this thesis,The precision and automatic drilling technology of multi-joint industrial robots for complex surfaces is taken as the research object by using theoretical analysis,simulation and experimental verification.The following technical problems of precision and automatic drilling of multi-joint industrial robots are deeply studied by theoretical analysis,simulation and experimental verification,including positioning problem,hole path problem,efficient and smooth operation between two points,hole accuracy problem.At last,the theoretical problems studied were verified by experimental methods.The machining characteristics of complex surfaces holes is analysed.The comparative analysis among commonly used complex surfaces hole machining methods has been done,and the model of the precision and automatic drilling technology of multi-joint industrial robots for complex surfaces is set up.Aiming at the problem model,this thesis firstly studies the precise positioning method of precision automatic drilling of multi-joint robot,expounds the principle of precise positioning of robot precise drilling,and describes the coordinate system involved in the machining system.The transformation method of robot space motion coordinate system is analyzed theoretically,and the calibration principle of system tool coordinate system and workpiece coordinate system is discussed.In this thesis,reverse engineering calibration method is used to discuss the calibration process in detail.In order to find the shortest and most efficient drilling path,the machining path planning method of complex surfaces holes is studied in this thesis.After analyzing several commonly used robot path planning algorithms,the thesis proposes the shortest path planning method.Based on the CAD model,the information of the holes is extracted,and some existing path constraints are analyzed.The path planning method for automatic drilling of curved parts by using improved ant colony algorithm is studied.The feasibility of the algorithm is verified by simulation examples.In order to study the best way of the movement between two points of robot.The method of robot space motion trajectory planning is studied.The joint space planning and Cartesian space planning method of trajectory planning are analyzed and described.In order to improve the drilling precision of the system,this thesis studies the backlash of the robot,analyzes the backlash generated by the multi-joint robot and its influence on the drilling process,and studies the backlash compensation method.Based on the above research,a precision and automatic drilling system of multi-joint industrial robot for complex surfaces is built.When making holes on the curved surface,the drilling can be fully automated and it has high efficiency.The hole positioning accuracy can reach 0.5mm and the size accuracy is within 0.05 mm.