Research On Control Strategy And Industrial Application Of Motorized Spindle Supported By Active Magnetic Bearing

Active Magnetic Bearing(AMB)can supply magnetic force to support the motorized spindle. Owing to its characteristics of no contact and active control, AMB possesses superior performance compared with the traditional bearing, such as long service life and high rotation precision. With the development of AMB, the motorized spindle with AMB is being gained more and more extensive attention. Control strategy and industrial application of the motorized spindle with AMB is studied in the thesis.A motorized spindle prototype with AMB was developed. The design parameters of each link in the prototype, such as AMB, rotor, sensor, power amplifier, were presented. The electromagnetic characteristics, the static deformation of the radial and axis magnetic bearing and the static and dynamic characteristics of the prototype were analyzed, including static stiffness, dynamic stiffness, mode, the critical speed and the unbalance response. The incomplete differential PID and the mixed sensitivity H ? control strategy were designed. The AMB capacity and the control performance with the two control strategies were investigated by the co-simulation of ADAMS and Matlab Simulink softwares. The static suspending and the high speed rotating of the prototype were realized with the incomplete differential PID and the mixed sensitivity H? control strategy based on F28335 DSP. Finally, the generalized dynamic stiffness, the critical speed, the temperature rising and the grinding performance of the prototype were investigated.The results showed that the prototype can be operated stably at the working speed of 42000r/min. The maximum vibration amplitude was less than 3?m under the two control strategies.The generalized dynamic stiffness of the lower radial AMB can reach 4N/?m, and the temperature rise of the driving motor and the AMBs were less than 30? and 20? respectively. Field grinding experiments demonstrated that the grinding precision can be satisfied with the requirements of electronic product and reach the level for industrial application.