Research Of Electrifying Control Method Of Permanent Magnet Spherical Motor Based On Trajectory Planning

As a novel multi degree of freedom(DOF)motion device,spherical motor(SM)has many advantages such as small volume,light weight and fast response speed.It has wide application prospects in aerospace,human limb prosthesis,satellite attitude control and other emerging fields,and has attracted increasingattentions.However,due to the special three-dimensional structure of permanent magnet spherical motor(PMSM),the motion mechanism is very complex in practical applications.Therefore,in this paper,the trajectory planning and electrifying method of a three DOF PMSM are studied.The main work of this paper can be summarized as follows:1.The basic structure of the PMSM is introduced,and the mathematical model based on the Lagrange equation and the physical model based on the virtual prototyping technology is established respectively.Then the torque-angle characteristic between the single stator coil and the permanent magnet is analyzed by Ansys software,and the electromagnetics modeling of the motor is completed by the principle of superposition.2.Through coordinate transformation,inverse kinematics solution and interpolation calculation,point to point trajectory(PTP)planning based on sinusoidal acceleration function and continuous trajectory planning based on cubic spline interpolation are proposed respectively.At the same time,we use ADAMS software to realize the dynamic simulation of the above trajectories.Simulation results confirm the effectiveness of the trajectory planning method.3.In order to enhance the electromagnetic torque generated by different coils,the spin torque and tilt torque of different combinations of coils are analyzed respectively.On this basis,the electrifying control methods of PTP motion and continuous motion are proposed,the current-torque equations are established,and the singular point of the motion is analyzed.The currents of the electrified coils are calculated and analyzed,and the simulation results confirm the feasibility of the electrifying control method.4.The experimental control platform of PMSM is built,and the electrifying control experiments of PTP spin motion,letters 'AHU' tilt motion and spherical spiral continuous motion are carried out.The hardware control system is designed based on stm32f407 controller,and the software design is completed under the MDK development environment,and the human-computer interaction interface is established by using the LabVIEW software.The correctness of the strategy proposed in this paper is verified by the experimental results.