Modeling and control of a high-thrust direct-drive spiral motor

In this paper, modeling and control of spiral motor is proposed. The voltage equation and motion equation of the spiral motor is proposed. Based on this modeling, control system for the spiral motor is proposed. The proposed controller consists of three parts; the first part is PI current controller with back EMF compensation specialized for spiral motor, the second part is disturbance observer based PD controller for linear and gap motion interacting each other, and the third part is zero-power controller for equilibrium fluctuation of gap displacement. It is confirmed that the proposed controller achieves independent linear position and gap control simultaneously.