Yasuo Oshinoya

Control of electromagnetic levitation transport of flexible steel plate (fundamental considerations on elastic vibration control under transport)

We have proposed a magnetic levitation control system for flexible steel plates and confirmed its feasibility through a digital control experiment. However, there is a risk that side slipping or the dropping of the plate may occur owing to inertial force, because the levitation control system does not provide any restraints for the direction of travel. Therefore, we have proposed the addition of electromagnetic actuators to control the horizontal motion of a levitated steel plate. In addition, we have reported that it is possible to suppress the elastic vibration of the steel plate in the vertical direction by using the electromagnetic actuators for horizontal positioning. In this paper, the effect of the magnetic field applied from the horizontal direction on the transport performance of a magnetically levitated flexible steel plate is reported.

Study on Horizontal Noncontact Positioning Control for a Magnetically Levitated Thin Steel Plate (Experimental Considerations on Elastic Vibration Control under Transport)

Thin steel plates are widely used in various industrial products. However, they have th e problems of flaws in the coating caused by contact support during transport and the deteriorati on of surface quality. As a solution to these problems, a noncontact transport of steel plates usin g electromagnetic force has been considered. However, there is a risk that side slipping or the dr opping of the plate may occur owing to inertial force because the levitation control system does not provide a restraint for the direction of travel. Therefore, we have proposed the addition of el ectromagnetic actuators to control the horizontal motion of a levitated steel plate. In addition, we have reported that it is possible to suppress the elastic vibration of the steel plate in the vertical direction using the electromagnetic actuators for horizontal positioning. In this paper, the effect of a magnetic field from the horizontal direction on the transport performance of a magnetically levi tated flexible steel plate is reported. We are close to achieving the practical application of a linear motor train that can travel at a speed of 500 km/h. If a linear motor train comprises approximately 16 cars, similarly to the current bullet trains, it will move as if a flexibly moving string material is levitated over a guideway, traveling at an ultrahigh speed without contact with the guideway. We can expect the occurrence of vibration and wave phenomena totally different from those that occur on bullet trains, which run at 350 km/h in contact with the rail via their iron wheels. It is theoretically possible to adjust the apparent rigidity of a train by assuming a string-form multiple-car train to be a superelastic body and applying a tensile force to the traveling connected cars. In a practical case, the tensile force applied to the entire train of connected cars will be adjusted by applying different propulsion powers from the guideway to each car (e.g., different powers around the first and end cars). We aim to change the rigidity of the entire train, in particular, the rigidity of the connecting sections between cars. To this end, we first clarify the mechanism of suppressing the elastic vibration generated when a tensile force is applied to an ultraflexible body in the noncontact method using the technique of controlling the electromagnetic levitation and transport of thin steel plates studied by our research group(1)-(4). The applicability of this mechanism to high- speed motion is also discussed. In this study, an ultrathin steel plate (0.18 mm thick) was magnetically levitated, and we carried out basic experiments to discuss the effect of a horizontal attractive force applied to the stationary levitated steel plate on its elastic vibration, with the aim of obtaining basic findings on various phenomena during motion.

Serpentine Movement on Superposed Trains of Differential Mechanisms

In this paper, a slender and cordlike differential mechanism is proposed, and the capability of its motion is examined. It has a high number of degrees of motion, many more than the number in the input required to drive it, since it is composed of many differential mechanism units, all of which are two-dimensionally connected to each other. Every unit is made up of a wired pulley which is free around the axis connecting two links. The mechanism is driven by three or more wires on which tension forces changing sinusoidally are applied by DC motors under feedback control using a personal computer. Consequently, progressive transverse wave motion similar to the serpentine movement of snakes has been successfully generated on the mechanism.

Electromagnetic levitation control of a traveling steel belt.

A method of magnetic levitation control of a traveling steel belt is presented. A traveling steel belt is supported in contactless manner by attractive forces of electromagnetic actuators which are controlled by feedback signals from gap sensors to stabilize the levitation behavior. A sub-optimal control theory is applied to minimize effects of spillover of residual vibration modes of the belt. To verify the usefulness of the method, an experiment of digital control was performed using a SUS430 steel belt.