مدل سازي و شناسايي تجربي پارامترهاي يك سيستم سروهيدروليك دوران با حضور عدم قطعيت هاي ساختاري و اغتشاش

Modeling and Experimental Identification of a Rotary Servo-Hydraulic System in Presence of Noise and Structural Uncertainties

In this paper, a study was done of the modeling and parameter identification of a rotary electro-hydraulic servo system in presence of noise and structural uncertainties. The mathematical model accounted for all the system dynamics, apart from few trivial assumptions that were put together to alleviate the complexity of the expressions. The behavior of the spool dynamics in servo-valve is modeled with an appropriate 2nd-order transfer function. In fact, electro-hydraulic systems are known to be highly nonlinear and non differentiate due to many factors, such as leakage, friction, and especially, the fluid flow expression through the servo-valve. Then the system is written in linear parameters (LP) form and continuous-time least-squares estimation method is used to parameter identification of the system. Furthermore, the constant parameters of the valve can be identified using frequency response methods. In comparison with similar works, the experimental results present significant reduction in identification time. The method is validated with the nonlinear model of the system and substituting the procured parameters in the model.