Optimization of Motion Control for a Variably Excited Linear Hybrid Stepper Motor

摘要

In industry, when precise movement is required, a hybrid stepper motor is often used. In practice, linear direct drives are often operated based on the hybrid stepper motor principle. The construction of the linear hybrid stepper motor (LHSM) is modified by adding coils that ensure a variable magnetic excitation. A model for the modified LHSM is developed, so that a control function can be found that makes the motor less noisy and, thus, more efficient. Based on the identified model, optimization is performed to find an appropriate control function for variable magnetic excitation. Implementing the proposed control function gives a quieter operation of the LHSM. A drawback of this operation mode is that the reduced thrust force in certain states can affect the motion controller. Therefore, for motion control, an optimization-based method to determine the controller parameters is introduced. In addition to the common PID controller, a nonlinear compensation controller is proposed. The proposed nonlinear compensation controller achieves better dynamic positioning accuracy.