Some practical methods for independent estimation of parameters of aviation system objects
Control and navigation systems
Аuthors1, 2, 2, 3
2. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
AbstractThe paper is devoted to the development of practical engineering methods of continuous real-time assessment (identification) of the unknown object parameters, which is based on the signals of measurement of input and output object coordinates.
The subject of the paper is connected with the proposed idea of independent (separate) evaluation of any/each of the unknown object parameters (e.g., dynamic coefficients of the airplane).
The paper aims at developing some practical methods and algorithms for separate estimation of the unknown parameters of static and dynamic aviation system objects.
The research method is based on preliminary formulation of a required system of equations with variable coefficients according to the signals of measurement of the input and output object coordinates. This equation system can be used for estimation of all unknown object parameters. Such system can be constructed, for example, on the basis of signals that contain current and past values of all measured coordinates. These values can be obtained by passing the signal through dynamic elements such as pure time delay links. Such signal processing provides for continuous calculation of the Cramer formulas determinants for the formulated equations system. This allows performing a reduction of the overall objective of estimation of all the unknown object parameters to a number of independent tasks of assessment of separate unknown parameters. After that these problems are solved via application of the methods of estimation of a single parameter in the presence of “measurement noise” such as the method of minimization of the current value of the squared error.
The estimation methods and algorithms, which were obtained during the research, can be used for the assessment of airplane dynamic coefficients as well as gradients of devices of object coordinate measurement or control channel. The paper presents some examples of obtaining the appropriate estimation algorithms and illustrates their effectiveness with the mathematical modeling results. This allows recommending the developed methods and algorithms of estimation of unknown object parameters for practical application, which will result in improvement of the quality of aircraft control systems.
The research proved the possibility of obtaining particular algorithms of automatic continuous evaluation of parameters of the static objects and dynamic objects, which can be considered as static objects, in the presence of “measurement noise”.
Accurate real-time measurement of aircraft control parameters is essential for enhancing its handling qualities. However, it is hard to assess these parameters precisely due to a number of complications. The paper offers a practically proven method for solving this problem.
Keywords:estimation, determinants of Cramer formulas, the residual error, the squared error, static objects and dynamic objects, dynamic airplane coefficients
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