Research On Motion Control And Compliant Interaction Strategy Of Cooperative Manipulator

With the rising of concepts such as "Industry 4.0" and "Made in China 2025",the transformation and upgrading of China’s manufacturing industry is the general trend.Nowadays,the robot field has become the main direction of China ’s manufacturing.However,traditional industrial robots are difficult to meet the needs of automated manufacturing due to their own structural and functional limitations.“Industry 4.0" regards human-machine cooperation as the optimal automation strategy,and the collaborative manipulator has developed rapidly under this demand.The emergence of human-machine collaboration has broken the boundary between man and machine.The harmonious coexistence of man and machine will be an important manifestation of the future intelligent factory.Aiming at the requirements of high efficiency and safety of human-machine cooperation,this paper studies the key technologies of trajectory planning,trajectory tracking and compliance control of cooperative manipulator.The main work of this paper is as follows:Firstly,the research background and significance of the subject are described.Combined with the research progress,the research status in this field at home and abroad is summarized.Some common key problems faced by the cooperative manipulator in motion control and compliant interaction are introduced,and the research content of this subject is put forward.Then,the kinematics model of the six-axis cooperati ve manipulator is established by using the improved D-H method,and the forward kinematics equation is derived.The workspace range of the manipulator is described by Monte Carlo method.The dynamic model of the joint angle of the manipulator is derived by Lagrangc method.According to the properties of the Jacobian matrix,the Cartesian dynamic model is established.Secondly,the polynomial is used to complete the point-to-point trajectory planning in the joint space.For the case of multi-path points,the classical cubic spline curve planning method is improved to avoid the start-stop impact of the manipulator.The planning of basic motioncurve elements such as straight line and arc is completed in Cartesian space.The quadratic programming of spatial interpolation point density and joint curve interpolation is studied.Based on the cubic spline interpolation,the quintic spline interpolation expression is derived,and the NSGA-II algorithm is used to solve the multi-objective optimal trajectory of timeenergy-impact.Thirdly,for the problem of accurate and stable trajectory tracking control of cooperative manipulator under the influence of external disturbance and parameter uncertainty,a terminal sliding mode controller is designed based on adaptive radial basis function neural network.The derivation of the control law and the finite-time stability proof of the system under the control law are completed.The simulation model is built in Simulink and compared with the existing research methods.The response time,maximum steady-state error and average steady-state error of joint angle tracking are evaluated to verify the effectiveness of the algorithm.Finally,the expression of impedance control in the joint space of manipulator is studied,and the modeling and simulation of two different forms of impedance control law in Cartesian space are completed.The influence of the coefficient matrix of the second-order impedance model on the flexibility of the manipulator is analyzed.The environmental dynamics model is built.Based on the admittance control algorithm,a parameter adaptive compliance control method is proposed to improve the flexibility of the end effector of the manipulator when it collides with the environment and the ability to quickly restore the original trajectory.