Reach On Human-robot Cooperative Control Of Robot Based On Force Interaction

With the development of social science and technology,the traditional industrial robot’s flexibility,intelligence and adaptability to the environment are gradually exposed.The robot system with human-robot collaboration function has stronger flexibility,workspace sharing and safety,which can overcome the shortcomings of traditional industrial robots and has higher market value.Human-robot cooperation system improves intelligence,but also brings many problems.For the man-robot cooperative control system,improving security and interaction is the key to man-robot cooperative control.The main difficulties and key problems are as follows:(1)identification of dynamic model parameters in active compliant control based on dynamic model;(2)position/force coordination control in active compliant control based on impedance model;(3)judgment of external force type in collision detection.Therefore,to study and solve the above problems is the basis of the robot human-robot cooperation control based on force interaction,which is of great significance to the development of robot human-robot cooperation.The objective of this paper is to realize the active compliance control and collision detection of the robot,and different methods are used for comparative analysis.In order to solve the above problems,the research ideas of this paper are as follows: For the problem of parameter identification of dynamic model,the method of finite Fourier series excitation trajectory and condition number is adopted;To solve the problem of position/force coordination control,a position-based impedance control method is used to adjust the position/force of human-machine coordination robot.In order to judge the type of external force in collision detection,the frequency domain analysis method to analyze and process the high frequency signal in external torque is adopted.Firstly,the dynamics model of the robot is established and linearized,the regression matrix and minimum parameter set are obtained,and the excitation trajectory simulation and verification are carried out based on MATLAB platform and finite Fourier series excitation trajectory.Secondly,the position-based impedance control algorithm is used to study the active compliance control.The principle and implementation method of impedance control are analyzed in detail,including impedance model,gravity compensation and free space force control.The simulation platform is built based on MATLAB/Sim Mechanics to verify the gravity compensation algorithm and free space force control.Then,the methods of fixed threshold and frequency domain analysis are used to realize the collision detection function in human-machine collaboration,and a summary and analysis are made.Finally,the Efter ER3 A six-axis robot is taken as the experimental object,and the operation and data acquisition of excitation trajectory,active compliance control based on dynamic model,gravity compensation of tool hand,active compliance control based on impedance model,and collision detection experiments of fixed threshold and frequency domain analysis are completed.The experimental results show that the active compliance control based on the impedance model has better drag effect than the dynamic model,and the drag force can be saved about15 N in each direction.The method based on frequency domain analysis can correctly identify the active contact force and accidental collision force,so as to verify the safety and intelligence of the human-machine cooperative control system designed in this paper.The research results of this paper have reference value for the research of human-machine cooperative control of robots.