LPV Modeling and Tracking Control of Dissimilar Redundant Actuation System for Civil Aircraft

Abstract

Dissimilar redundant actuation systems (DRAS) are in practice in advanced aircraft in order to increase reliability and to resolve the actuator failure issue due to common cause. This paper addresses the problem of force fighting that occurs due to dynamics mismatch of two dissimilar actuators in DRAS and provides a method to achieve precise tracking of aircraft control surface. The nonlinear system dynamics are first transformed into linear parameter varying (LPV) form using recursive least square (RLS) method. The LPV observer based controller is then designed to synchronize the positions of dissimilar actuators in DRAS and to drive the control surface smoothly. By applying linear matrix inequalities (LMIs), parameter dependent Lyapunov function (PDLF) is obtained to achieve global stability and to compute the controller and observer gains. To test controller according to real flight condition, an external disturbance signal that acts as air load is applied at the control surface input. Several simulations on the nonlinear system validate the dominant performance of proposed controller as compared to the existing methods in literature.

Force Equalization Control of Redundant Electromechanical Actuation System by FOPID and Current Feedforward

“…The Monte Carlo method is used to verify the robustness of control effect. The factors that have the greatest impact on the sensitivity of system force fight are mainly [16] : transmission efficiency deviation of reducer, position signal offset, position sensor delay, speed signal offset, and transmission clearance.…”

“…Many scholars have applied controllers for force equalization, among which Zhang [14] of WIU in 2014 proposed a PID feedback method to compensate for the position signal, and force fight of the dynamic response process was significantly reduced. 2019 Salman et al of Beihang University [15] [16] based on force fight problem of a dissimilar redundant actuation system, used the least squares method to transform the nonlinear system into a linear system, applied linear matrix inequalities (LMIs) to design disturbance observers and controllers, which have good control effect for external load disturbance signals, but state observers can only compensate for limited types of disturbances. In 2020, XUE from Shanghai Jiao Tong University [17] proposed a set of force equalization algorithms based on the pressure difference and position compensation feedback and validated the control method on the Iron Bird platform.…”

Motion synchronization for the SHA/EMA hybrid actuation system by using an optimization algorithm

“…[17][18][19] tried to force (compel) the HA/EHA system to follow trajectory motion state's signals (position, velocity and acceleration signals) for motion synchronization. Various control techniques, such as integral sliding mode control, LPV-and LPV-based integral sliding mode control, are used to solve the problem of the force fighting with precise motion tracking for the HA/EHA system [20][21][22][23]. An integral action controller that is designed uses position and force signals to reduce force fighting.…”