ゴム製空気圧アクチュエータの制御性能

Abstract

A pneumatic actuation is anticipated to be applied to more rigorous servo-type motion controls. Especially, it is possible to construct a novel flexible actuation system using the high compliance due to air compressibility. A newly developed pneumatically driven rubber actuator has been constructed for this purpose. Also, its application to robot manipulators or hands is being actively studied. However, the fundamental control characteristics are yet to be studied in depth, so the knowledge about this actuator is not sufficient for designing a servo system.In this study, the static and dynamic characteristics are examined experimentally. Also, a position servo system was constructed with this actuator and PWM pressure control valves, of which the control performance is discussed. The principal results can be summarized as follows.1) Both the displacement and the output force of this actuator are very sensitive to the operating pressure.No dynamic delay exists in the conversion process from pressure to force, and its dynamic characteristic depends only on the operating pressure response. Therefore, to apply this actuator effectively as a servo actuator, a high response and high accuracy pressure control is required.2) The PWM pressure control valve with the high speed on-off solenoid valve is effective for driving this actuator.3) Although this actuator has a considerably large hysteresis, even the usual linear controller can provide the almost satisfactory control performance within this experiment.