基于电流分配系数自适应修正的平面电机解耦控制

Decoupled Control for Planar Motor Based on Self-Adaptive Correction for Current Distribution Coefficient

对于模型参数具有不确定性的平面电机运动系统,电流分配策略是引起其多自由度耦合行为的本质。但现有解耦控制的研究主要集中于各运动自由度控制算法的设计,没有从电流分配的物理层面解决耦合问题。论文针对平面电机三自由度解耦控制,建立了各线圈单元通电电流与三自由度位移输出之间的ARMA(auto regressive and moving average)模型,以实测输出与估计输出之间的残差平方最小为优化目标,提出了一种基于电流分配系数自适应修正的解耦控制算法,并给出了可用于实际控制的递推离散化方法。通过在线调节,使电流分配系数估计值逼近实际模型参数,从物理本质减小了多自由度耦合作用。采用轨迹跟踪实验,并与基于数据解耦控制方法进行对比,结果表明该方法提高了平面电机的定位与运动精度,验证了其对一类MIMO(multiple input multiple output)运动系统多自由度解耦的有效性。

For the planar motor motion system with uncertainty model parameters, the scheme of current distribution is the essence that causes the coupling effects between multi-degrees of freedom. The recently research on decoupled control was mainly focus on the control algorithm design of each degree of freedom, by which the problem of coupling was not solved from the physical level. In view of the decoupled control for the planar motor with three degrees of freedom, the ARMA(auto regressive and moving average) model is established by the current input and the position output of each coil, and the minimum square of residual error between the measured output and the estimated output is applied as the objective, then a decoupled control method is proposed on the basis of self-adaptive correction for current distribution coefficient, and the recursive discretization model is given out, which can be used in the actual control. By online adjustment, the estimated current distribution coefficients will approximate the actual model parameters, and then the coupling effects can be reduced from the physical nature. The trajectory tracking experiments are carried out, comparing with the decoupled control method of data base, and the results show that the positioning and tracking performance are improved. Thus the decoupling effectiveness for MIMO(multiple input multiple output) motion system is verified.