Application of Nonlinear Correction Method for Attitude Control and Landing Oscillations Prevention

Abstract

The purpose of this work is to demonstrate the application of the nonlinear correction method to prevent attitude oscillations of flying vehicles. This paper investigates the complications of manual control tasks in aeronautics caused by employing the integral component in the control loop. If the actuators of aircraft controlling surfaces reach their rate limits, the aircraft oscillations can appear for both manually and automatically piloted cases. In this paper, the oscillations alleviation problem is solved using the nonlinear correction method. A general methodology for pilot-induced oscillations prevention is described briefly by the example of an aircraft pitch control system. The obtained pilot model parameters are used for altitude control system examination. The nonlinear systems analysis is carried out by calculating the generalized sensitivity function for the control and disturbance input signal. In the second part, the application of the nonlinear correction method to prevent aircraft and satellite oscillations caused by integrator windup. A comparative analysis of the nonlinear correction and the customary anti-windup feedback is carried out. The results obtained demonstrate that a sequential nonlinear corrective device can be efficiently used to suppress pilot-induced and integrator windup oscillations.