Magnetic levitation control with real-time vibration analysis using finite element method

Abstract

The authors propose the magnetic levitation control of thin steel plates using the real-time finite element analysis of the vibration. This paper describes the concept of the proposed levitation system, the finite element simulation of presuming the displacement, and the applicability from the viewpoint of calculation time. There is a requirement to improve the quality of the thin steel plates, in the steel making process. The thin steel plates used for the body of automobile requires high quality paint for the improvement of a fine sight. It is required that steel plates prevent occurring of the wounds because of flatting the surface. Current conveyance system uses the rollers with contact in the manufactural process of the product. This system, however, has the problem of causing the wounds in surface of the plates. Contact-less transportation schemes are thus required in the manufacturing processes, and the magnetic levitation technology is one of the most expected ones. The thin steel plates vibrate more easily than the thick ones because of their high flexibility. The analysis of the vibration modes (1) and the application of Hrobust control theory (2) are the conventional countermeasure of the problem. High order controller is successfully used in the both system, however it is not always available in the real application. One gap sensor for each electromagnet is required without exception and causes the high cost of the total system. This paper proposes the magnetic levitation control of the thin steel plates using the real-time finite element analysis of the vibration. There are interactions of supporting force between the plural elec- tromagnets and the consideration of dynamic vibration is therefore necessary. This system aims at the stable levitation by presuming the vibration of the plate and observing the force of the electromagnet. This system can omit the gap sensor. This paper shows the concept of the proposed levitation sys- tem, the technique of analyzing vibration using finite element method, and simulation of presuming the displacement.