抄録
According to the recent rapid development of micro-processors, an intelligent control for an electro-hydraulic servo system will be comparatively easily realized by using microcomputers. In order to realize intelligent control systems, it is indispensable to get a digital control valve with high switching speed performance as the transducer and actuator. The aims of this study are to propose a high-speed control method for displacement of the valve spool and to develop a high-speed digital valve having a switching speed within 200, μs. In this study, a couple of multilayered piezo-electric ceramic devices, commercially available, are used to drive the spool of the valve directly. Introducing a kind of feed-forward control and providing some improvements in the electric driving circuits, an on-off type spool valve with the transient response within 120μs of the switching speed is successfully developed to pull out capabilities of the PZT device to the utmost limit.
