| The price of industrial robots is relatively low,and the working space is ample;their processing intelligence is also higher.At the same time,the robot has better flexibility in aviation,aerospace,and shipbuilding,which need large size and high precision processing requirements of precision manufacturing gradually expanded and applied.However,the structure of a serial industrial robot is an articulated cantilever beam,and its joint stiffness is low,resulting in low trajectory accuracy of the robot end.The trajectory accuracy will be further reduced under external load interference,which hinders the further promotion and application of robots in machining systems.In order to solve this problem,this thesis mainly does the following research.The basic theory of SMART5 NJ 165-3.0 industrial robots are analyzed,including the basic structure,operation mode,and coordinate system of robots used.The pose representation,kinematics analysis,and system modeling of industrial robots were studied,the spatial pose description method of the robot was defined,and the D-H kinematics model of the robot was constructed.Matlab carried out the kinematics simulation,and the D-H model was verified.It provides a theoretical basis for robot trajectory planning and precision control.With the goal of improving the robot end trajectory accuracy,the research on the antidisturbance algorithm of the robot is carried out based on a comprehensive analysis of the robot kinematics.The force feedforward-position feedback trajectory error composite control compensation strategy is proposed,and the external disturbance force compensation calculation model is established.The mechanical characteristics of the robot body structure are analyzed by Adams simulation analysis software,and an external disturbance simulation verification model is established.The numerical simulation study of force disturbance compensation is completed.The accuracy of the proposed mathematical model of force feedforward disturbance compensation is verified by the comparison of Adams simulation results and Matlab calculation results.The robot control system is developed.Based on the COMAU robot C5G OPEN control system,combining force sensor,laser tracker,and the proposed compound compensation strategy,the communication program of the force sensor,laser tracker,and its host computer with the robot is written.The dual-thread communication between the sensor and the robot is realized,and the information about external disturbance and the terminal trajectory of the robot can be obtained simultaneously.The online error measurement and disturbance real-time control compensation system of an industrial robot with a laser tracker and force sensor was constructed.The communication test was carried out after the system was built.The hardware foundation is laid to realize robot trajectory precision compound control.The experimental results are compared to verify the proposed algorithm.Based on the online compensation system of robot error and disturbance,the measurement error of the sensor is analyzed,and the measurement noise of the force sensor and laser tracker is analyzed.The real-time accuracy and disturbance compensation of the robot’s machining trajectory is carried out,and the error and disturbance compensation of the static and dynamic paths are completed.Experimental results show that the proposed method has strong robustness and can maintain high trajectory tracking accuracy under external load,which lays a foundation for highprecision robot machining under complex working conditions. |
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