LQ-servo Design for Magnetic Levitaton systems with a Passive Carrier Considering Disturbance of LSM

Abstract

To look at the transfer system of LCD, OLED, semiconductor, etc, it used a roller and rotary motor system in the past. The disadvantages of this system are contaminated conveying vehicle by foreign substances attached to roller, breakdown of the glass itself caused by the vibration of the conveying vehicle, etc. In particular, large dust collecting systems were required to minimize dust while being transported. Such factors largely caused the high cost of LCD, OLED, and semiconductor. To improve these, non-contact magnetic levitation transport systems have been proposed and studied. If applying the magnetic levitation transport system, it may reduce dust, noise, and so on, apply curved track rail, and reduce scale of track, which may lead to space saving. To look at the structure of such a magnetic levitation distribution transport system, it can be divided largely into propulsion system and levitation system. This paper investigated two systems: as propulsion system, LSM whose control accuracy is high and response speed is fast although equipment ratio is higher than LIM and as levitation system, EMS that does not require permanent magnet and less expensive in consideration of economic feasibility although control difficulty may be higher than Hybrid-EMS. If applying LSM as propulsion system, normal force for levitation is generated. This force acts as disturbance in controlling the levitation system. This levitation disturbance is difficult to be measured, realistically. This is why there is a difficulty in applying the levitation disturbance to design a controller for the levitation system. This paper aims to predict such a LSM levitation disturbance through FEM analysis and propose its application into LQ-servo control design, state-of-the-art technique Chapter 2 describes the EMS (ElectroMagnetic Systems)-type levitation electromagnet using magnetic equivalent - iii - circuit and Chapter 3 identifies the characteristics of the existing PID controller and predicts the LSM disturbance through FEM analysis. Based on the facts predicted through the FEM analysis, this paper proposes its application into LQ-servo control design, state-of-the-art technique. Based on the findings from the previous chapters, Chapter 4 compares two controllers through matlab simulation and verifies the proposed method through experiment. Chapter 5 makes a conclusion to the designing of LQ-servo controller in non-electric-approved magnetic levitation system considering LSM disturbance through simulation and experiment.