| The accuracy and robustness of robot control system is an important research topic in the field of robotics.In recent years,the wide application of fractional calculus in science and engineering has attracted more and more scholars' attention.Compared with the integer order system,fractional calculus can establish a more complete mathematical model for complex systems and industrial processes.The fractional control system has better dynamic response and robustness,and provides a new theoretical support for the development of various disciplines.The traditional sliding mode control can guarantee the asymptotic stability of the system,but there is chattering,and the system could not reach the sliding mode surface in finite time.However,in motion control of robot,in order to ensure higher control accuracy,system state needs fast convergence.The fractional order sliding mode control of industrial robots is studied in this paper.The main contents of this paper are as follows:The overall design and the configuration of FVR6-6423 robot system are introduced.The hardware of the system consists of four parts: the optical part,including the web industrial camera and the light source;the mechanical part,including the conveyor belt,the manipulator and the PC control center;the PLC logic control part;the pneumatic system,including the end suction nozzle and the rotating cylinder.The software design is mainly the host computer control interface.Taking a six degree of freedom series manipulator as the research object,D-H kinematic model is applied to determine the location relationship between joints.Forward and reverse kinematics analysis of the manipulator.The simulation analysis is carried out in the Robotics Toolbox of MATLAB.The results verify the accuracy of the theoretical analysis of industrial robot kinematics and the correctness and effectiveness of the model establishment.A synchronization strategy based on discontinuous activation function for delayed fractional order complex networks is proposed.By using the principle of hamper control,some key nodes of the system are hampered.Based on fractional Lyapunov stability theory,a new state feedback controller is designed,and the synchronization rule of fractional order complex network is obtained.Finally,the effectiveness of the proposed method is verified by simulation experiments.It lays a theoretical foundation for studying the fractional order sliding mode control of robots.Aiming at the chattering problem of industrial robot sliding mode control method,a sliding mode control theory based on fractional order adaptive law is proposed.By designing the global nonsingular terminal sliding surface,the fractional adaptive reaching law is applied to approximate the switching gain in the control,thus weakening chattering.The fractional calculus is used to combine the speediness of the system change and the strong robustness of the sliding mode controller to ensure the stability of the system and the boundedness of the tracking error.A global fractional order sliding mode control method based on Fuzzy adjustment gain is proposed.Combining the characteristics of fractional order sliding mode control and fuzzy control,the global fractional order sliding surface is designed,so as to inhibit the chattering effect.Meanwhile,by setting the switch gain,we set the upper bound unknown external disturbances to ensure the robustness of the system.Finally,the effectiveness of the proposed control method is verified by simulation experiments. |
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