Method for collision detection of manipulator based on friction disturbance compensation
Since the human-machine mutual assistance manipulator suffers physical human-machine interaction safety in un-known complex working environments,a method of collision detection is proposed based on friction disturbance compensation.Firstly,the manipulator's dynamic model is set up with the help of the Newton-Euler method,and the dynamic linearized regres-sion recombination model is derived to work out the dynamic parameters to be identified.Secondly,the manipulator's excitation trajectory is optimized,and the trajectory data is collected,so as to identify the dynamic model's parameters by means of the least square method.Thirdly,the friction force is regarded as the disturbance term of the manipulator's joint motion;the general-ized momentum is used to set up the second-order disturbance observer,in order to estimate the force exerted on the manipulator's joint friction;both the LuGre dynamic friction model and the genetic algorithm are used to characterize the system's friction characteristics,and thus the external torque observer is constructed based on friction disturbance compensation.Finally,the data is collected for test of collision detection.The results show that the method for the manipulator's collision detection based on fric-tion disturbance compensation has high accuracy in detection and can effectively improve the safety of human-machine cooperation in different unknown working environments.
human-machine mutual assistance manipulatorcollision detectiondisturbance observerLuGre dynamic fric-tion model
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