Mohammadi Farhadi R. Robust control of an unmanned aerial vehicle at low speeds

The object of research - processes of designing robust control systems of UAV in conditions of uncertainty; the purpose of the study is to increase the efficiency of unmanned aerial vehicle control systems in conditions of the uncertainty of dynamics that operate at low speeds by developing methods for synthesizing robust control laws; research methods - identification of UAV dynamics; optimization of nonlinear criteria and synthesis of robust control; the theory of control in the state space and frequency domain for the construction of a UAV dynamic model and an automatic control system; robust stability and analysis of the robustness and quality of the UAV; the theory of random processes for the simulation of perturbations; The theory of H∞ synthesis and minimization of structure singular values for the synthesis of robust control; the theory of automatic flight control; the theory of digital systems; the results - a combination of methods for identification and synthesis of robust control based on μ-synthesis and PID-laws for typical and new UAVs allows to obtain adequate mathematical models of UAV according to various criteria, to synthesize laws of robust control and to shorten the time for designing and testing of automatic control systems, excluding reconfiguration of its parameters; Novelty - the method for identification of the UAV dynamic model and estimation of the uncertainty bounds was developed, which differs from the use of a priori information regarding the rational choice of family of linear models in nonlinear optimization, which ensures the adequacy of the models used for the synthesis of robust control; the method of synthesis of robust control based on μ-synthesis is improved due to the scaling of control signals, which compensates for changing the content of the control matrix of the linear model depending on the square of the air velocity and simplifies the procedure of robust control synthesis of the UAV dynamic model under uncertainty conditions; further developed the methods of direct synthesis of robust and adaptive robust PID-regulators under uncertain nonlinear dynamics of the object for the synthesis of UAV control, due to the use of a nonlinear criterion with the separation of parameters for sensitivity to two groups and the change of UAV model by introducing artificial delay and gain model, which allows to reduce the space of parameters that are adjusted, and increase the stability margin of the system; the degree of implementation - the results are implemented in the Interdisciplinary Research Institute of Problems of Physical Modeling of Aircraft Mode Operations of the Kharkiv Aviation Institute; the educational process of the National Aerospace University named after N. Ye. Zhukovskiy "Kharkiv Aviation Institute"; "Aeroinzhiniring" Ltd; field of application - UAV robust control system;