High-Precision Positioning Control of Magnetic Levitation System

Abstract

In this paper, we introduce two position control scheme; the lead-lag control and the sliding mode control for a stage system, which is levitated and driven by electric magnetic actuators. This consists of a levitating object (called platen) with 4 permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion by the vertical and horizontal forces. Dynamic equations of the stage system are derived simply. The sliding mode control algorithm is more effective than the lead-lag control algorithm to reduce effects from movements and disturbances of other axis.

Nonlinear control of maglev positioning stage

“…J. W. Jeon studied the simple dynamics equation based on the magnetic levitation positioning stage, and designed a leading-lag controller and a variable structure controller [4], but no description of the relation between the force and the winding current was given. According to the same principle, we designed a maglev two-dimensional positioning stage which consists of a moving table (non-magnetic alloy material), 4 permanent arrays, four stators, displacement sensors, etc.…”

“…These devices can provide micro-even nanopositioning accuracy, large range movement and enough rigidity. Maglev positioning stage, in addition, has the advantages of non-contact, frictionless and no abrasion, which attracts great attention [1][2][3][4][5][6].…”

The Research on the Model of a Precision Magnetic Stage System

“…Since the vector control decoupling plan is introduced the magnetic suspension platform the control, the effective control method has been produced.Jeong-Woo Jeon [3] discusses decoupling compensator's control plan based on the forward feed compensation method, this control method can stabilize in the small scope the system from unstable original state to the balanced shape, and, its error increases along with the deviation balance point distance expands, when the vertical direction has the wide range movement, the horizontal direction affects will be created greatly. Ding et al [4] proposed an H control methods on the basis of the input decoupling, that is effectively suppressed effects of x, y position of the direction to suspension height.…”