Multi-manipulator Force/position Hybrid Control Based On Fuzzy Adaptive

In recent years,the cooperative manipulators system has become a hotspot in the field of robotics due to its advantages of flexible operation,wide applications,high safety and so one.However,the cooperative manipulators system is a highly nonlinear system with highly coupled state variables and strong external interferences,which makes it difficult to control multiple manipulators by using traditional control methods.In addition,the internal forces will be generated when cooperative manipulators work together to carry the same object.These internal forces should be controlled within a reasonable range.If not,it will influence the control precision of the whole system and even will damage the object.Therefore,the suitable control strategy should be designed to deal with the above problems and realize the force/position control of the cooperative manipulators system.It is worthy of researching and has important practical significance.In order to deal with the problem of force and position control of cooperative manipulators system,adaptive fuzzy backstepping controller,adaptive fuzzy command filtering controller and finite-time command filtering controller are designed by combining backstepping method,command filtering technology,finite-time technology and fuzzy adaptive control in this thesis.The main results of this thesis are as followsFirstly,the force/position control method of cooperative manipulators system based on backstepping method is studied.The dynamic model of the cooperative manipulators system is constructed based on dynamic equation of the manipulator.Then the backstepping method is proposed to design tracking controller,and the fuzzy adaptive control method is used to deal with the nonlinear items and interference terms of the system.Meanwhile,the stability of the system is proved by using Lyapunov theory.The simulation results show that the designed control strategy based on backstepping method can effectively control the object's trajectory and the internal forces of the cooperative manipulators system.Secondly,the force/position control method of cooperative manipulators system based on command filtering technology is studied to deal with the problem of acceleration discontinuity.By combining the command filtering technology and the backstepping method,the system only needs the information of object's trajectory and speed,which can effectively deal with the above problems.And the error compensation mechanism is introduced to reduce the influence of filtering error.The simulation results show the effectiveness of the command filtering backstepping method in cooperative manipulators system,and the cooperative manipulators system can work normally when the acceleration is discontinuous.Thirdly,the force/position control method of cooperative manipulators system based on finite-time technology is studied.Based on the backstepping method,the control performance of the cooperative manipulator system is improved by combining with the command filtering technology and the finite-time technology,which make the position of the object and internal forces track the desired trajectory faster.And a new error compensation mechanism is proposed to ensure that the error compensation system converges in a shorter time.The simulation results show the effectiveness and the superiority of the finite-time command filtering method.Finally,the backstepping control strategy,the command filtering backstepping control strategy and the finite-time command filtering control strategy are studied and compared by using the simulation results.Trough the comparison,it can be seen that these three control strategies can realize the force/position control of the cooperative manipulators system.However,the finite-time command filtering control strategy can make the position and internal forces of the system track the desired trajectory faster,and tracking accuracy and control effect are better than the other two control strategies.