Adaptive Control of Active Magnetic Bearing against Milling Dynamics

Abstract

For improving the defects in milling processes caused by traditional spindle bearings, e.g., the dimensional discrepancy of a finished workpiece due to bearing wear or oil pollution by lubricant, a novel embedded cylindrical-array magnetic actuator (ECAMA) is designed for milling applications. Since ECAMA is a non-contact type actuator, a control strategy named fuzzy model-reference adaptive control (FMRAC) is synthesized to account for the nonlinearities of milling dynamics and magnetic force. In order to ensure the superior performance of spindle position regulation, the employed models in FMRAC are all constructed by experiments. Based on the experimental results, the magnetic force by ECAMA is much stronger than that by the traditional active magnetic bearing (AMB) design under the same test conditions and identical overall size. The efficacy of ECAMA to suppress the spindle position deviation with the aid of FMRAC has been verified as well via numerical simulations and practical metal cutting.

Adaptive Feedforward Control of a Pressure Compensated Differential Cylinder

“…Newer applications of adaptive control systems include adaptive friction compensation with an adaptive velocity estimator to compensate for the estimated non-linear friction force [15]. In [16], a fuzzy model reference adaptive control of an active magnetic bearing for a milling process is investigated to reduce the milling dynamics. Adaptive integral robust control of an electro-hydraulic servo system is investigated in [17], using parameter estimation and integral control to compensate for disturbances and plant uncertainties.…”

Effects of Imperfect Assembly and Magnetic Properties on the Three-Pole AMB System

“…It can also be applied in extreme environments, such as very high or low pressure, very high or low temperature, vacuum, and zero gravity. Because of these features, AMB has found wide applications, for instance, in turbo-molecular pumps [2], high-speed air compressor [3,4], flywheel energy-storage systems [5,6], control-momentum wheels [7], printed electronics systems [8], and machine tools [9], etc.…”

Performance Analysis and Experimental Research of Electromagnetic-Ring Active Balancing Actuator for Hollow Rotors of Machine Tool Spindles

“…With the promotion of Industry 4.0 technology, intelligent spindles integrated with actuators and sensors will be the direction of future development of machine tool spindles [1,2]. These actuators are considered as legs and arms of intelligent spindles, including chatter suppression actuators [3][4][5][6], thermal error compensation actuators [7,8], bearing preload actuators [9,10], active balancing actuators [11] and so forth.…”