Research On Inverse Control For Nonlinear Hysteresis Of GMA

With the development of precise engineering technology changes rapidly, precisionpositioning is widely used in many fields. Giant magnetostrictive material (GMM) has theadvantages of fast response, large strain and good reliability, and it is the most ideal material tomake precision actuator. As the core part of Giant magnetostrictive actuator (GMA), GMM hasthe inherent nonlinear hysteresis, which leads to the serious nonlinearity and poorreproducibility between driving magnetic field and displacement output in GMA. Andconventional PID control which is used to control GMA has the defects of overshot and longsettling time, etc. In order to solve these problems, some research based on the actuator whichis developed by the laboratory is done as follows:Firstly, magnetostrictive fundamental and the characteristics of GMM are introduced indetail, and the causes of nonlinear hysteresis are analyzed. Based on Jiles-Atherton model, adynamic hysteresis model with the effects of temperature, prestress and eddy current isestablished. An improved PSO algorithm is used to estimate the model parameters.Secondly, the characteristic and classification of existing neural network control and theproperty superiority of CMAC are introduced. After solving the problem of "one to many"mapping that exists in CMAC hysteresis model, a control system of feed forward compensationcontroller based on GMA hysteresis inverse model is established.Thirdly, the theory and implementation of the fuzzy PID controller is introduced, and thecontrol effectiveness of the common PID controller is used to compare with it by MATLABsimulation. After analyzing the simulation results, it confirmed that the system includes bothCMAC feed forward inverse compensation controller and fuzzy PID controller can improve theperformance of the control system greatly.Finally, the process of GMA hysteresis nonlinearity control experiments is designed,experimental data further demonstrated that CMAC can reduce hysteresis error and improvethe controllable precision of actuator effectively, and the factors which influence the precisionaccuracy is analyzed.