Study Of The Digital Controller Of The Active Magnetic Bearing Based On DSP

Active magnetic bearing (AMB) is a new type supporting part. It was a typical mechatronics product and involved electromagnetic, mechanics, rotordynamics, control theory and computer science. The emphasis of the dissertation was placed on the digital controller of the AMB and the main contents listed as follows:Firstly, this paper summarized the general situation and the current development of the electromagnetic bearing control technique and the key problems that face. Secondly, on the basis of the principle of the magnetic bearing, deduced the nonlinear relationship between the magnetic force and control current, rotor's displacement in single-degree-of-freedom, from which the magnetic force formula under two-degree-of-freedom was presented. Thirdly, the hardware system based on TMS320VC33 was presented including AD circuit, DA circuit, serial communication circuit and etc. Experiment was carried out on each part. Fourthly, to the inherent characteristics of the AMB, different control algorithms were presented under different scopes. In the linear scope PID algorithm was adopted to eliminate the static error and improve the dynamic performance. And in the nonlinear scope the fuzzy logic algorithm was adopted to suit for the nonlinear characteristics. Software including control algorithm for 5 degree-of-freedom, AD interrupting, communication with PC was worked out. Finally, the 5 degree of freedom control system with the PID+FUZZY algorithm. was tuned .The rotor's liftoff tracks were presented under single-degree-of-freedom and the two-degree-of- freedom and the results between digital controller and analog controller were compared, furthermore the stiffness of the AMB system was validated. Furthermore , study and analysis on the theory of EMC was also included .