Coupling Characteristic And Control System Of 2-DOF Direct Drive Induction Motor

With the development of technique,2-degree-of-freedom(2-DOF)motor and its control system have been given more and more attention.A novel 2-DOF direct drive motor(2DOF-DDIM)was proposed.It is composed of rotary and linear arc-shape stators and a shared mover,which is capable of rotary,linear and helical motion.The motor,which has simple structure,high material utilization and multi-dof motion,has a good application prospect in grinding miller,helical auger,drilling machine,robot and human artificial limb field.There is special coupling effect in 2DOF-DDIM.In this paper,the analytic method and finite element method(FEM)were applied to analyze the induced and moving coupling effect.It was concluded that the induced coupling field is produced by diffusion of magnetic field,which is related to the source frequency and magnetic field intensity.Moreover,because of the existence of moving coupling effect,the linear motion was obstructed by rotary magnetic field and vice versa.Thus the rotary and linear coupling coefficients were imported to compensate moving coupling effect.On the basis of mathematical model of linear induction motor,the special model of 2DOF-DDIM was established taking both the longitudinal end effect and moving coupling effect into account.Then the simulation model was built in matlab/simulink.The accuracy of the mathematical model was verified by comparing the its results with FEM.The speed detecting scheme was proposed aiming at the multi-dof motion of 2DOF-DDIM.The feasibility of the speed open-loop constant voltage frequency ratio control system and the rotor field oriented vector control system was discussed in consideration of different application environment.The two control system were modeled in matlab/simulink.The practicability of them were verified.