Three-degrees-of-freedom control of electromagnetic levitation and two-dimensional linear synchronous drive for a flexible transport lines

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I have proposed a three degree-of-freedom control of electromagnetic levitation, in which a single electromagnet with four poles and four windings can be stabilized by itself independently. The design of the controller is investigated and experimental tests have shown excellent features of the proposed control scheme. Also the zero-power control, in which the magneto-motive force from permanent magnets supports the weight of the levitation magnet so that the average winding currents in the magnets' windings may be zero, has been proposed and the dynamic electrical and mechanical behaviors of the magnet has been studied in detail. The interaction between magnetic levitation control and linear drive has been experimentally studied when the electromagnet is used as a field magnet as a long-stator one-dimensional linear synchronous motor. The armature flux of the linear synchronous motor and mechanical oscillation during the linear drive may be continuous and oscillatory flux- and force-di … More sturbances to the levitation controller. We proposed semi-zero-power control, which is a combination of the zero-power command with the fundamental gap-length controller using information from a force-disturbance observer in order to design a robust levitation controller under the common situation combined with a linear synchronous drive. The semi-zero power -control has been compared with a slow zero-power : The former control scheme has been superior since it makes possible to adjust the frequency response of the levitation control arbitrarily between ones of the gap-length control and zero-power control.The first drive test was executed with a relatively long one-dimensional track on which armature sides of linear synchronous motors are attached. The position and speed feedback controls have shown feasibility of precise controls in the one-dimensional drive experiments.As the final step, a trial of the combination with a two-dimensional linear motor has been carried out at Nihon University in cooperation with Prof. Ohira and Dr. Inui, who are experts of the research on two-dimensional linear motors. Fundamental functional tests of levitation control and turnout drive were carried out with this two-dimensional base on an open-loop position control, since it was difficult to build a two-dimensional position sensing system for a closed-loop control with simple instruments. There was slight saying motion observed in the two-dimensional drive tests for this reason, as well as since there was no active way for suppressing yawing deviation. However, it has been experimentally verified that a smooth two-dimensional control, in which the magnet follows arbitrary trajectory references, is possible by giving appropriate armature currents by following simple calculations for their current commands. Possibility of implementing visual servo control was also theoretically investigated for a further development of a precise control of the two-dimensional closed-loop drives although there was no time to try it experimentally anymore. Less