Multi-objective optimization of a reluctance actuator for precision motion applications

Recent research and assessments have shown that the reluctance actuator is a promising candidate to drive the next generation precision motion system of the lithography machine in the semiconductor industry. This paper proposes an multi-objective optimization algorithm for an optimal design of E-core reluctance actuator considering the requirements of the precision motion system. The objectives of optimization include maximizing the output magnetic force, minimizing the mass and the time constant of the actuator, and driving the actuator stiffness value to zero. First, the characteristics of the reluctance actuator are expressed in terms of the design variables of the reluctance actuator. After that, the optimization algorithm using the Grid search method and Pareto optimal approach is proposed to obtain the optimal design of the reluctance actuator. Finally, the optimal design of the reluctance actuator is implemented in a precision motion system example. The simulation results are obtained using Finite Element Analysis in COMSOL to check the saturation of magnetic flux in the reluctance actuator. The dynamic response of reluctance actuator motion system is obtained in the time domain for different inputs to verify the optimal design of the reluctance actuator.