Research On Impedance Control Of Robot Arm Based On Six-Dimensional Force Sensor

The key to realizing the national strategy of "Made in China 2025" is to realize intelligent manufacturing,and robots are the key to realizing intelligent manufacturing.As a kind of robot,the mechanical arm mainly performs tasks requiring compliant operation,including welding,spraying,assembly,handling and polishing.Compliant operation of manipulator arm mainly depends on the compliant control of mechanical arm force,which can accomplish a lot of complex work.Therefore,the compliant control of manipulator arm is an important research direction in the field of robot at present.Focusing on the compliance control of the manipulator,this paper studies the identification method of the dynamic parameters of the end load of the manipulator,the perception of the end contact force,the detection method of the end impact position and the impedance control strategy.Firstly,the kinematics and dynamics of the manipulator are studied.The kinematics and dynamics model of the manipulator is established and the simulation analysis and verification are carried out.The simulation results prove the correctness of the established kinematics and dynamics model of the manipulator.Secondly,the method of sensing the contact force and detecting the impact position of the end of the manipulator is studied.With seven degrees of freedom hydraulic overloading redundant manipulator as the research object,research the load at the end of the mechanical arm/torque and the gravity sensor zero error compensation method,and according to the redundancy hydraulic overloading manipulator motion relation model in simulation experiment,the results show that the proposed method can eliminate the mechanical arm end load deviation,the influence of gravity and the sensor zero get end contact force/torque,It is more accurate to use the contact force/moment to detect the end impact position.Thirdly,the identification method of dynamic parameters of the end load of the manipulator is studied.With seven degrees of freedom hydraulic overloading redundant manipulator as the research object,the end of the mechanical arm was established load dynamics parameter identification model,design the movement joints of mechanical arm was the optimal incentive trajectory,parameter identification of hydraulic overloading manipulator end load is applied to the simulation experiment,and evaluate the identification parameters under validation trajectory,results show that the parameter identification results and reliable.Finally,the impedance control strategy of the manipulator is studied.The impedance model was established,and the influence of impedance parameters on impedance control performance was analyzed.The genetic algorithm was used to find the optimal combination of impedance parameters.The stability and convergence of the adaptive impedance control system are analyzed by introducing the adaptive control strategy and adjusting the adaptive rate online.The simulation results of the adaptive impedance control system show that the robustness of the control system is good,and the manipulator can achieve force tracking control well in unknown environment.