Hysteresis Modeling And Control Of Precision Reluctance Actuators

As the precision of manufacturing is continuously improving and the efficiency of manufacturing is required to be raising,advanced manufacturing technologies continue to develop in a high-precision and high-speed way.The driving system,as the core unit of manufacturing equipment,needs the higher performance.Reluctance actuators have the advantages of large force density and low energy consumption relative to voice coil motors which are commonly used.However,there are many difficulties in the process of nonlinear modeling and controlling caused by the hysteresis effect.This thesis intends to establish the magnetic circuit and electromagnetic force model of reluctance actuators considering the hysteresis effect,do research on the improvement of hysteresis modeling,establish the simulation model of a reluctance actuator system,build an experimental platform and do analysis on it,and do research on the algorithm of compensation controlling for magnetic hysteresis effect of reluctance actuators.The main contents are as follows:This thesis introduces the basic magnetic circuit and electromagnetic force equation of reluctance actuators;based on the Duhem model and the modification function,establish the magnetic and inverse magnetic hysteresis model between the magnetic induction strength B and the magnetic field strength H and do research on the erasing,consistency properties;for a typical reluctance actuator,an equivalent magnetic circuit model is established by taking into account the changes in the cross section of the magnetic circuit,and then deduce the nonlinear expressions of between the current and the magnetic induction strength or the electromagnetic force with hysteresis effects,and analyze the characteristics of these expressions.Considering the center asymmetry of the hysteresis loop,propose an method that using modification function which has different shape in different quadrant to improving the modeling accuracy,and six-parameter model and four-parameter model are compared in aspect of modeling accuracy;considering the effect of air gap change on hysteresis loop of reluctance actuators,do research on the relationship between the control parameters of the modification function and the air gap,and establish an improved hysteresis model which taking into account air gap change;build system simulation model of the reluctance actuator based on the magnetic circuit,electromagnetic force and circuit equation with hysteresis effects;build a static and dynamic experimental platform about the reluctance actuator;calculate the magnetic induction strength by directly and indirectly measuring and integrating data;measure and analyze hysteresis characteristics of the reluctance actuator as the input voltage and air gap is different;Through the comparison of simulation and experimental results,the improved hysteresis model is verified correctly.The nonlinear control algorithm of reluctance actuators is compared and analyzed considering the hysteresis effect;the closed-loop control of current,force and displacement using the PID controller are designed for the simplified linear model of reluctance actuators,and the control effect with these PID controllers is analyzed;the compensation control strategies with the inverse hysteresis model and the adaptive multi-layer neural network hysteresis model are respectively designed and used in the closed-loop control of the force and position,and then do the simulation and comparison in aspect of control effects,and it shows that both strategies can effectively compensate the nonlinear hysteresis effect;the influence of the parameter change in the hysteresis model on the control effect is studied,and it shows that the adaptive multi-layer neural network hysteresis compensation control has the ability to adapt to the parameter change in the hysteresis model.