Nonlinear dynamic characteristics and optimal control of MSMA actuator subjected to harmonic magnetic field and stochastic excitation

Abstract

A novel magnetic shape memory alloy (MSMA) actuator is proposed in this paper, which has fast response speed and large deformation, and its nonlinear dynamic response and control are studied. A new differential term is developed to explain the MSMA’s stress-strain curves. The dynamic model of the MSMA actuator subjected to harmonic magnetic field and random disturbance is established, and its nonlinear dynamic characteristics are obtained. Finally, the stochastic dynamic programming control is introduced to enhance the drive accuracy. The results show that the perturbation plays an important role in the system’s dynamic response; dynamic programming control can improve the actuator’s accuracy in strong stochastic perturbation. These results will be helpful for the optimal design and development of MSMA actuators.