Numerical Study of Nonlinear Hydromechanical Aircraft Systems

At present, automatic control systems are mainly developed by linear methods. This is due to the existence of a consistent theory of linear analytical methods, which has been developed over many decades and has its own mathematical apparatus and software. The analysis of accuracy, stability, and controllability and the further synthesis of linear systems are performed surprisingly simply and clearly. At the same time, linearization involves cumbersome mathematical transformations, which may lead to difficult-to-interpret results. Moreover, linearization is inapplicable to the cases of strong impacts, nonstationary systems, and significant nonlinearities. The development of the general theory of numerical experiment and, simultaneously, the hardware and software of computers allows one to analyze systems without linearization because the same information, also in a more reliable form, can be obtained directly by the numerical study of systems. And some parameters, e.g., accuracy, can be obtained analytically from the same differential equations. In this article, by the example of a typical problem, it was shown how accuracy, stability, and controllability can be analyzed using the initial differential equations without resorting to analytical methods.