D-Q-P vector control method with shaft response factor on 3-DOF 4 poles spherical PM motor

3-DOF spherical PM motor has 3 degrees of freedom in its motion by tilting and rotating the shaft, which is applicable in various fields. In this paper, D-Q-P vector control method is proposed for motion and speed control of the shaft. Using the reference table of current is the conventional control method obtained through numerous simulation and experiments. Vector control of general rotary motor has been researched for a long time. The vector control is the main control method in rotary motor because it allows an instantaneous torque control. But in the case of 3-DOF spherical PM motor, locus of magnet rotation varies by shaft position. So general D-Q axes vector control methods can´t be applied directly. This paper shows D-Q-P vector control method for 3-DOF 4 poles spherical PM motor considering shaft response factor with mathematical and experimental verification.