Method of cogging force compensation for linear motor based on model identification and iterative learning

Cogging force impacts the performance of linear motor in its process of movement, which limits the application of the linear motor in the field of high precision servo. A cogging force compensator was utilized to improve the control precision of linear motor. Without modification of system structure, by taking advantage of accelerometer to gather data of cogging force and determining model structure utilizing spectral analysis, a specific model was identified after RLC. With the model identified, a compensation controller for cogging force was designed combining compensator based on position model with iterative learning control. Both the simulation and the experiment demonstrate the tracking error caused by cogging force can be reduced considerably through this method.