Font Size: a A A

Principle Analysis And Control For Pressure Impluse Test Of Airplane Hydraulic System

Posted on:2008-12-11Degree:DoctorType:Dissertation
Country:ChinaCandidate:J LiFull Text:PDF
GTID:1102360218957129Subject:Detection Technology and Automation
Abstract/Summary:PDF Full Text Request
Hydraulic system is one of the important systems in airplane, whereas pressureimpulse of airplane hydraulic system may usually tend to fatigue failure of hydrauliccomponent, and even cause serious accident, therefore hydraulic component of airplanehydraulic system must be subjected to the pressure impulse test according to the aviationstandard. The kind of test can not only examine the fatigue resistance of hydrauliccomponent but also find the problem in design, so the test is useful to improve designand enhance reliability of airplane system. The current domestic study in the field ofairplane hydraulic pressure impulse is relatively weak because it is at the primary stage.Satisfying the practical national demand for new type plane, this study investigates theairplane hydraulic pressure impulse.The study is concerned with the pressure impulse test of the airplane hydraulicsystem. The kind of pressure impulse test system is new general test system whichbreaks through the limit of existing product and can control all kinds of wave for varioustype of hydraulic component in complex circumstance. Focusing on the particularity,complexity and advancement of the test system, the research in the dissertation includessome parts as following. At the first place, the principle of test is analyzed and a precisemathematical model of fluid inside pipeline based on characteristic method isestablished, what is more, theâ… type model andâ…¡type model are establishedrespectively according to the different realization principle between water hammer andsine wave, trapezoid wave, then dynamic process of test is simulated. This outcomeshows that the model is correct and accurate. On the basis of the model, the key factorswhich affect water hammer are analyzed and the important conclusions are reached. Inthe second place, meeting demand for various test of water hammer, a parallel controllerof CMAC and traditional controller is designed forâ… type model. Combining theadvantage of CMAC and traditional controller, the parallel controller which ischaracterized by self-adaptation and self-learning can control water hammer for varioustest components. Simulation and practice indicate the controller has such favorablecharacteristics of high control accuracy, short settle time and strong robustness. Finally,three kinds of intelligent control algorithm are presented for test of sine wave andtrapezoid wave. Control for sine wave and trapezoid wave belongs to a problem oftrajectory tracking and is different from water hammer control, so new control algorithm is required. The PID control fails to meet the demand for control accuracy due tononlinear and time-varying property of test system, therefore, some adaptive controlalgorithm such as DRNN-based NMPC, P type close-loop ILC and self-studying CMACare presented in the dissertation. DRNN-based NMPC uses DRNN as the predictivemodel of nonlinear system and heuristic genetic algorithm with global optimal ability asrolling optimization tool. The simulation result shows this controller has better controlperformance than PID. Under P type close-loop ILC, high precision of control can beachieved after finite iteration because initial value and over fitting problems are solved.Compared to DRNN-based NMPC, P type close-loop ILC is characterized by better realtime and higher control accuracy. CMAC self-studying controller is a new typecontroller which combines the advantages of ILC and CMAC with the localgeneralization and the memory ability. It has best tracking behavior due to using NNPIDas feedback control.It is proved that the system model presented is correct, simulation is higheraccuracy and the adaptive intelligent control algorithm designed in the dissertation canmeet the control demand for various test. These outcomes which are demonstrated bytheoretical analysis and practice are significant to promote the process of nationalstandardization of pressure impulse test.
Keywords/Search Tags:pressure impulse, Cerebellar Model Articulation Controller, heuristic genetic algorithm, Nonlinear Model Predictive Control, Iterative Learning Control, Diagonal Recurrent neural network
PDF Full Text Request
Related items