Synergetic Synthesis of an Amphibious Aircraft Autopilot for the Problem of Steady-State Planing under Conditions of Wind-Wave Disturbances

The work examines the problem of controlling an amphibious aircraft (AA) in steady-state planing mode under the influence of wind-wave disturbances. An analysis of modern approaches and methods for the synthesis of aircraft control systems was carried out. A brief overview of existing scientific works devoted to the control of AA in various modes of movement is presented. The necessity of developing an autopilot to control the longitudinal movement of an AA is substantiated. A review is made of the characteristics of the state of the water surface and their influence on the operation of an AA on water. An analysis of the influence of external disturbances on the planing stability of AA is presented, on the basis of which the use of the integral adaptation method on invariant manifolds is justified for the synthesis procedure of a vector nonlinear controller of the control system of an AA in planing mode under the influence of wind-wave disturbances. The approach uses the synergetic principle of "expansion-compression" of the phase space, on the basis of which an extended model of synergetic synthesis is first constructed, taking into account estimates of the action of disturbing influences, and then, when applying the synthesis procedure, a phased compression of the phase space is carried out by introducing invariant manifolds, at the intersection of which the fulfillment of a given technological task is guaranteed, and invariance to the action of wind-wave disturbances is also ensured. The results of the study are confirmed by computer modeling of a synthesized closed-loop control system for the aircraft; in particular, it is shown that the closed-loop system guarantees the maintenance of the required flight speed and altitude, as well as maintaining the trim angle in the required range of values.