Anti-Disturbance Tracking Control Of Flexible Manipulator Systems Based On Disturbance Modeling

With the rapid development of modern industry,many complicated tasks such as welding and coating will be completed by using high-precision manipulator.Flexible manipulator has the advantages of light structure,low energy consumption,strong adaptability to working environment,flexible operation and high working efficiency,so it has gained great development spaces in medical,aerospace,material science and other high-tech areas.Nevertheless,compared with the traditional rigid manipulator systems,the flexible manipulator is more vulnerable to external disturbance and deformation,which increases the control difficulty and reduces the control accuracy.Therefore,the research on anti-disturbance control of flexible manipulator has always been a hot issue in the field of control engineering.In this thesis,the model of flexible manipulator is taken as the research object,the influence of various types of disturbance is studied,and an effective anti-disturbance control algorithm is proposed based on the disturbance observer design and robust control strategy,to ensure the stability and good dynamic performance of flexible manipulator under the influence of disturbances.The main contents of this paper are as follows:(1)The development of flexible manipulator at home and abroad is introduced the modeling process of flexible manipulator model is discussed,and the mathematical equation of flexible joint manipulator is established by using Lagrange dynamical equation based on the Spong model.(2)The problem of anti-disturbance control of flexible manipulator system is discussed by using disturbance observer method.On the one hand,the disturbance observer is constructed to estimate the modeling disturbance on the basis of the extended disturbance models,and the composite controller is further designed to complete the dynamic compensation of the modeling disturbance by using the PI type control input and the disturbance estimation information.On the other hand,the L1performance index is introduced to suppress the influence of bounded disturbance on the controlled system.In addition,based on Lyapunov analysis method,the closed-loop flexible manipulator system can achieve satisfactory stability and dynamic tracking performance.(3)The problem of anti-disturbance tracking of flexible manipulator system with unknown states is discussed by T-S disturbance modeling.The T-S fuzzy model is introduced to describe the irregular and nonlinear disturbances,a full-dimensions observer is designed to estimate the unknown disturbances and states.Furthermore,by combining the PI control structure,the state and the disturbance estimation information,a composite controller is constructed to realize the dynamic compensation for the external disturbances and the effective control of the system.Based on convex optimization method,the favorable dynamic performance of the flexible manipulator system can be verified.(4)The problem of anti-disturbance control of flexible manipulator system is discussed by using neural network disturbance modeling.The neural network model with adjustable parameters is introduced to model the irregular and nonlinear disturbances.Both the disturbance observer and the L1 performance index are designed to realize the dynamic estimation and optimization of multi-source disturbance.Based on convex optimization algorithm and designed adaptive control method,the dynamic parameters of neural network is adjusted,and the observer gain and controller gain are calculated to guarantee the favorable stability and dynamic tracking performance of the flexible manipulator system.(5)All the above algorithms are realized by simulation model.The harmonic disturbance,attenuation harmonic disturbance,bounded disturbance and sawtooth wave disturbance are explored to realize the anti-disturbance control of the flexible manipulator system and the effectiveness of the algorithm can be verified.