Simulation of an electro-hydraulic servo-valve in NUT programming environment

The paper deals with simulation of static and transient response of an electro-hydraulic servo-valve, which contains an electro-mechanical transducer (as a torque motor), a nozzle-and-flapper valve and a sliding spool in sleeve. For composing the mathematical model of an electro-hydraulic servo-valve the block schemes of the multi-pole functional element and subsystem models are used (Grossschmidt 1997; Grossschmidt and Vanaveski 2000 Grossschmidt 2001). For setting the relations between variables the oriented graphs are used (Grossschmidt 2001). The Runge-Kutta integration procedure combined with iteration procedures are implemented for computing the processes in the subsystems. The values of variables between the subsystems are also computed using the iteration procedure. All the computing programs have been written in NUT language (Uustalu et al. 1994). The NUT language is a high level object-oriented language, which supports the automatic composing of the computing programs. The problem description takes place graphically on the computer screen. Plots of the dependencies are displayed automatically after executing of the computations. The program package is implemented on a Sun Station.