Research On Control Method Of Human-robot Coordinated Motion Based On Force Information

With the innovation and development of robot technology,the working mode of the robot is gradually changed from doing simple task alone to completing the complicated task by human–robot cooperation.In the process of human–robot cooperation,it is necessary for the robot to be able to interact with the people in a natural way,so the study of human– robot coordinated motion control has an important theoretical significance and practical application value.In order to improve the stability and safety of human-robot cooperation system,reduce the operator's labor intensity,enhance comfort of operation,the method of admittance control with variable damping is put forward.Firstly,the human-robot interaction is analyzed,the model of human-robot interaction is established.And the human upper limb model is simplified,the kinematics and dynamics model of the arm are established by D-H method and Lagrangian mechanics analysis method respectively.The human-robot interaction force information is used to infer the operator's movement intention,and be made as the theoretical basis for setting the initial parameter value of the controller.Secondly,the difference between human-robot cooperation force control and robot force control is analyzed,and the human-robot coordinated movement model is established,thus admittance control method of the human-robot coordinated motion is confirmed.Against the variety of the operator's motion parameters and the variable characteristics of the operator's arm impedance in the process of human-robot cooperation,in order to improve movement control effect,the method of admittance control with variable damping based on human-robot interaction force information is put forward,the relationship between the damping change and the information of human–robot interaction force information is obtained by applying the experimental method.Thirdly,the transfer function of human-robot coordinated motion system is se up,and the stability analysis of the system is carried out,the relationship between the impedance parameters that should be satisfied is determined when the system is stable.First of all,the influence of the admittance control parameters on the operating force and the expected speed is analyzed by simulating the operator's force information input;then the simulation model of human-robot coordinated movement is established,and the influence of human-robot interaction model parameters and admittance control parameters on human-robot coordination motion is analyzed.Finally,the experimental system of human-robot cooperation is set up,the control system program is written.Multiplayer experiment is carried out and admittance control parameters are determined.The experimental results show that the control method designed in this paper can achieve human-robot coordinated movement and ensure the stability,safety and compliance of the system.