Research On Position Detection Method For Rotor Of Permanent Magnet Spherical Motor Based On Optical Sensors

As a new type of multi degree of freedom(DOF)motor,the rotor of spherical motor is designed as a spherical structure,and it can perform a specific form of multi DOF motion in three-dimensional space.Compared with conventional multi DOF motion mechanism,spherical motor has smaller mass and volume,and simpler mechanical structure,it has wide application prospects in aerospace,robots and other fields.In the current research of closed-loop control of spherical motor,rotor position detection technology is one of the key technologies to achieve accurate rotor control,which still restricts the development of spherical motor.Under the above background,the position detection method of spherical motor rotor is studied in this thesis.The main research work is as follows:1.Firstly,the basic structure of permanent magnet spherical motor(PMSM)is introduced.Then,the coordinate systems of stator,rotor and spherical are established respectively,and the coordinate transformation between stator and rotor coordinates is realized based on the rotor position representation.2.Firstly,the basic structure,working principle and communication mode with external equipment of ADNS-9800 optical sensor are introduced.Then,the hemispherical shell is installed on the output shaft of the spherical motor rotor.The motion information of the hemispherical shell is detected directly by optical sensors,and the position of the spherical rotor is obtained indirectly.Finally,the experimental platform is built,and comparing experiment with the rotor position detection method based on the MEMS sensor,the experimental results verify the feasibility and accuracy of the scheme.3.Aiming at the disadvantage that the quality of hemispherical shell affects the output of rotor torque of spherical motor and its large volume affects the practicability of detection device,the rotor position detection method of PMSM based on three optical sensors is proposed.The corresponding hardware detection module based on three optical sensors is designed and the experimental platform is built,Meanwhile,comparing experiment with rotor position detection method based on MEMS sensor,the experimental results verify the practicability and precision of the scheme.