Electro-hydraulic servomechanisms (EHSM) are important components of flight control systems and their role is to control the movement of the flying control surfaces in response to the movement of the cockpit controls. As flight-control systems, the EHSMs have a fast dynamic response, a high power to inertia ratio and high control accuracy. The paper is devoted to the study of the sensitivity for an electro-hydraulic servomechanism used for an aircraft aileron action. The mathematical model of the EHSM used in this paper includes a large number of parameters whose actual values may vary within some ranges of uncertainty. It consists in a nonlinear ordinary differential equation system composed by the mass and energy conservation equations, the actuator movement equations and the controller equation. In this work the focus is on the sensitivities of the eigenvalues of the linearized homogeneous system, which are the partial derivatives of the eigenvalues of the state-space system with respect the parameters. These are obtained using a modal approach based on the eigenvectors of the state-space direct and adjoint systems. To calculate the eigenvalues and their sensitivity the system’s Jacobian and its partial derivatives with respect the parameters are determined. The calculation of the derivative of the Jacobian matrix with respect to the parameters is not a simple task and for many situations it must be done numerically. The system stability is studied in relation with three parameters: m, the equivalent inertial load of primary control surface reduced to the actuator rod; B, the bulk modulus of oil and p a pressure supply proportionality coefficient. All the sensitivities calculated in this work are in good agreement with those obtained through recalculations.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Sensitivity analysis of eigenvalues for an electro-hydraulic servomechanism


    Contributors:

    Conference:

    9TH INTERNATIONAL CONFERENCE ON MATHEMATICAL PROBLEMS IN ENGINEERING, AEROSPACE AND SCIENCES: ICNPAA 2012 ; 2012 ; Vienna, Austria


    Published in:

    AIP Conference Proceedings ; 1493 , 1 ; 977-982


    Publication date :

    2012-11-06


    Size :

    6 pages





    Type of media :

    Conference paper


    Type of material :

    Electronic Resource


    Language :

    English



    Sensitivity analysis of eigenvalues for an electro-hydraulic servomechanism

    Stoia-Djeska, M. / Safta, C.A. / Halanay, A. et al. | British Library Conference Proceedings | 2012


    Microprocessor-Based Model Reference Adaptive Control of an Electro-Hydraulic Servomechanism

    Edge, K. A. / Figueredo, K. R. A. | SAE Technical Papers | 1989


    Micorprocessor-based model reference adaptive control of an electro-hydraulic servomechanism

    Edge,K.A. / Figueredo,K.R.A. / Univ.of Bath,School of Engng.,GB et al. | Automotive engineering | 1989


    Clutch Engagement Control by Electro-Pneumatically Operated Servomechanism

    Tanaka, H. / Wada, H. / Society of Automotive Engineers of Japan | British Library Conference Proceedings | 1992