Research On Active Vibration Suppression Of Servo Driven Flexible Manipulator

Flexible manipulator has the advantages of lightweight,low energy consumption and high load ratio.In recent years,it has gradually won popularity in advanced manufacturing,biological medicine,deep space exploration and other fields.However,the harmonic reducer and lightweight linkage mechanism make flexible manipulator easy to vibrate in motion,which will further dramatically reduce working efficiency and control precision of flexible manipulation.Therefore,taking servo-driven flexible manipulator as the controlled target,this thesis carries out in-depth research on utilizing input shaping technique and piezoelectric intelligent material to suppress its vibration.Firstly,this thesis introduces the research status of vibration suppression technology of flexible manipulator at home and abroad.Based on which,elastic deformation model and dynamic model of flexible manipulator are built with assumed modes method and Lagrange equation.Through Ansys and Matlab simulation,the accuracy of the models is validated and there comes the conclusion that the first mode of flexible manipulator occupies a dominant position,and truncation of the first model can not only simplify the design of controller but also reflect the vibration situation of the flexible manipulator.Secondly,feedforward input shaping technique is utilized to suppress flexible manipulator vibration.The analysis and design of several input shapers are illustrated in detail,and more attention is paid to the research of vibration suppression effect and robustness of the shaper.The simulation result shows that input shaping technique can effectively suppress the vibration of flexible manipulator.Simply increasing the number of pulses of the shaper is not very helpful in improving vibration suppression effect and it can also slowdown the response speed of the system.However,the increase of the constraint conditions of vibration equation derivation can significantly improve the vibration suppression effect and robustness of the shaper.Thirdly,for the further suppression of the vibration of flexible manipulator,vibration sensor and brake use piezoelectric material to form a closed loop feedback vibration suppression system.D optimization criterion is used to locate the best vibration suppression position of the piezoelectric element,and improved particle swarm is used to optimize PID controller that can suppress the vibration of flexible manipulator.The simulation result shows that the root of flexible manipulator has the maximum strain value and therefore it is the optimum vibration suppression position where piezoelectric element can be installed.Compared with traditional PID control,this control plan is capable of accelerating the convergence of vibration curve and significantly improving vibration suppression effect.Finally,a summary is made according to the overall work of the thesis.It points out the inadequacy and weakness in the research and also expects the direction and focus of the research in the future.