Study Of The Control Of Thulium Permanent Magnetic Spherical Stepper

Many kinds of motors, such as AC, DC servo motors, steppers, which are currently used in robotic, wrist, laser cutter etc, can't effectively meet the needs of such complicated systems because of their high speed, small torque and one-DOF and therefore the spherical motor, which can provide many DOF, has been attached much important since the development of the complicated control system.Permanent magnetic spherical stepper (PMSS) is a novel kind spherical motor, which has advantages of simple structure, small volume, light weight and high torque etc. The control method was discussed on the dissertation.At first, the control method based on the table was presented. The current windings can be attained according to the table which consists of all possible stable positions.And then the control method based on weighted graph was presented. A weighted graph is given which consists of all possible stable positions, and then the current windings can be attained according to the algorithm of the weighted graph.At last, the closed loop control method was presented. The surface painting of rotor and the place of optoelectronic sensors were analyzed, the commuting strategy can be attained and therefore the spherical stepper can be controlled to achieve the expected trajectory according to the algorithm of the weighted graph and the signal feedback from optoelectronic sensors.