An intelligent position control of electro-hydraulic linear drive

Fluid power actuators are characterized by their high power density and excellent dynamic response. The hydraulic actuator in particular is capable of very high output power levels combined with very compact drive unit dimensions. It is ideally suited to many high dynamic applications in modern machines and mechanical systems. However the disadvantages of hydraulic system such as non-linear dynamic behaviour due to friction, fluid compressibility, etc, need to be overcome. This is successfully obtainable only by implementation of modem digital control systems designed on basis of modem control theory. In other words the modern electro-hydraulic drive has to posses more and more inteligence. The objective of many researchers is therefore to develop an algorithm which would be able to control the drive without any a-priori knowledge of geometrical, operating or any other parameters of the system. A contribution to achieve above objective is represented in this paper. The essential part of proposed new control structure is a position feedback fuzzy logic controller, designed as a self learning system. The results of experimental investigations are also shown.