The Plane Mechanical Manipulation Of The Hydraulic Power Unit In The System Dynamic Performance Simulation

Hydraulic power drive unit (PDU) is the indispensable constituent of the primary manipulation system of modern aircrafts, the dynamical characteristics of which is a necessary precondition for aircraft's excellent control quality, and also an important standard to estimate design level of an aircraft's force-aided manipulation system. Through Building up numerical models of PDU, applying numerical simulation technology to test and adjust systematic parameters and performances has important engineering applying value and prospect for improvement of systematic design prediction, as well as reducing development time and cost.With aid of Matlab/Simulink software platform, the research work of this thesis builds up the numerical models of the common hydraulic PDU of primary aircraft manipulation system, and conducts numerical computation and simulation to their dynamic qualities and responses under typically applied actions. A software package to simulate the dynamic performances of the hydraulic PDU is developed through C⁺⁺ Builder software system. The main research work in this thesis is as follows:Based on hydraulic drive dynamics, automatic control theory and thoroughly understanding the working principle of hydraulic PDU, the research work studies in detail the structural parameters of hydraulic PDU, and makes them into mechanical models through simplifying the different structural forms. The math descriptions to the different structural models are wholly summed up for the linear and non-linear models; also the opened and closed-loop transfer functions of the complex control systems are derived.Through Matlab/Simulink modeling and simulation technologies, based on the above mentioned math models, the thesis builds up three simulation models of hydraulic PDU commonly used in aircraft, that is, basic model, the model with elasticity and clearance of support structure and the model with displacement feedback of support structure, among which many non-liner components of the PDU are retained. The dynamic time-domain responses of the three hydraulic PDUs are simulated under typical input signal modes, and the frequency-domain stability and margin characteristics of the three models in linearization are computed and described visually.Under the Integrated development environment (IDE) of Borland C++ Builder, the research work realizes engine-calls and parameter transfers between C⁺⁺ program and Matlab tools. A visual software package with interactive windows for structural parameters input, visually numerical simulation and post-processing is developed for preliminary engineering design and response simulation to hydraulic PDU of force-aid manipulation system of aircraft.With help of the developed software package, the numerical simulations and visual descriptions are conducted to three hydraulic PDUs with engineering structuralparameters, and their systematic response characteristics under different input signals and stability qualities are analyzed in the thesis.