Modeling and Control of a Levitating Linear Motion Platform

Abstract

This paper explores the application of a levitated linear motion platform implemented using linear flux-switching permanent magnet bearingless motors (LFSPM BMs). Flux-switching permanent magnet (FSPM) motor is an attractive motor type owing to its cost-effectiveness, which is achieved by placing the permanent magnets in the mover. Levitated linear motors are beneficial in special applications where, e.g., cleanliness and frictionless motion are needed. The paper focuses on accurate system modeling and control of a scaled -down proof-of-concept. The motor under study was modeled using the finite element method, yielding look-up tables of the force model, and by employing analytical equations of the motor. Simulation results are provided for a model-based levitation controller and a proportional-derivative (PD) traction controller. Challenges arise from the inherent force ripple when moving along the rail and from the slow inner loop bandwidth of the small-scale design of the system.