The Application Of Inversesystem Method To Electro-Hydraulic Driving Force Control System

Electro-hydraulic servo system have altitudinal nonlinearity. And this problem is not still solved well. It is caused by the throttling property, because of the existing of the servo valve, proportion valve and throttling valve, by the dead band, the back lash, the saturation. The nonlinear caused by the latter (usually called Nonlinearity in essence) has been solved by the describing function technique. But to the former, there is no satisfying method.The paper establishes the electro-hydraulic force control system nonlinear pattern close to the actual system. In past, the processing mode as to the electro-hydraulic servo-system nonlinear problem is that using the Tai's lux formula obtains the part linear pattern behind the series expansion at the stable state work-point. This kind of linear model is feasible to this system which work point is in small scope changing. Because As for the force control system, there is a two-scale differential part more in the numerator than the position control system and the velocity control system, so it will not only influence the system's performance but also cause the system lose its stability. However, in modern times the electro-hydraulic servo-system is living that the system work-point frequently is changing in great scope, and it should have the ability to drive big load. The part linear pattern is not successful. So to design the system of high precision, strong adapt is more and more imminence. To contrast, liner model is also established.For this reason, the paper is aimed at the electro-hydraulic servo-system nonlinear problem, and proposes the feedback linearity means (that is the inverse system method) against the system mode systematically to transform such nonlinearity into the pseudo linear system. The system mode not merely continues to have system message completely feedback the linearity means, but also achieves the great limit linearization of controlled device, for designing the controller to advance system dynamic characteristic and performance index and supply the ideal terrace in the interest of the application linearity control theory. Simulation and test results indicate that the proposed control strategy can track the target signals in the presence of changing inner place the greater limit in...