基于遗传算法的直驱XY平台变增益交叉耦合控制

摘要

对于永磁直线同步电机驱动的XY平台,轮廓加工精度易受到系统动态非线性、不确定性因素以及曲线轨迹的轮廓误差模型相对复杂等问题的影响.为了削弱以上影响,实现XY平台的高精度轮廓跟踪控制,设计了变增益交叉耦合控制器来补偿X、Y轴的耦合误差,并采用遗传算法对其中的PID控制器参数进行寻优,利用基因突变的能力,避免其陷入局部最佳解,从而快速准确地找到全局最佳解,使得系统轮廓误差达到要求的精度范围.理论推导与仿真结果表明,所设计的控制系统能有效提高XY平台的轮廓加工精度.%The contouring accuracy of XY table directly driven by two permanent mgnet linear synchronous motors is easily influenced by the dynamic nonlinearity and uncertainty of system as well as the relstively complex contour error model of curve trajectory.To weaken the above influences and achieve the high precision contour tracking control of XY table,the variable-gain cross coupling controller was designed for compensating the coupling error of X and Y axes.Genetic algorithm was used to optimize the parameters of PID controller.The parameters were avoided falling into the local optimal value by utilizing the ability of gene mutation.Consequently,the global optimal value can be found quickly and accurately,and the contour error of system can reach the required accuracy range.The theoretical analysis and simulation results show that the designed control system can effectively improve the contouring accuracy of XY table.