Design and Control of a Decoupled Rotary-Linear Switched Reluctance Motor

A decoupled two-degree of freedom in the linear and rotary directions of a motor based on switched reluctance principle is investigated. First, the structure of the motor is introduced, and the design procedure for the main parameters of the motor is elaborated. Also, the magnetic decoupled structure for the motor is illustrated. Second, a magnetic circuit analysis is given to explain the decoupled structure, followed by a simulation finite element method, including the inductance profiles, force and torque outputs, etc. Meanwhile, a control method for this motor is provided by using two proportional-integral-derivation controllers to regulate the linear position and the rotating angle independently. Linear force distribution function and torque sharing function are employed by the control system. Third, experimental results involving the force and torque measurements, linear position, and rotating angle responses are obtained, under specific loads and without a load. The motor is capable of realizing high-precision rotary and linear tracking within 0.3° and 500 μm under specific loading conditions, respectively. It suggests that the proposed structure can readily realize decoupled control proposed by this paper.