Switched reluctance motor for hybrid motion control: design, modelling, and sensorless drive

A new switched reluctance motor for hybrid motion control is presented in this study. The motor can control both motions simultaneously and separately. A dedicated sensorless drive is developed for each kind of motion based on diagnostic pulse injection method. Eliminating the position sensors in the motor with two degrees of freedom reduces the manufacturing cost and complexity. Each kind of motion is controlled independently therefore no decoupling algorithm is required. The motor has been mainly designed to eliminate rotary to linear gears to be used as an automatic drilling tool. The cylindrical translators let simultaneous excitation of all coils on the linear stator and provide short magnetic flux paths which reduce the magnetic core losses and increase the force per volume. The motor design is verified initially by running three-dimensional finite-element analysis (FEA) on both rotary and linear sections. The motor is fabricated and tested in the lab utilising the sensorless drive. Accordance of experimental values with the FEA results certifies the performance and applicability of the motor.