Stochastic Anti-Disturbance Flight Control for Helicopter Systems With Switching Disturbances Under Markovian Parameters

Trajectory Tracking Control Based on a Composite Disturbance Observer for Unmanned Autonomous Helicopters under Multiple Disturbances

“…Yet, as for the anti-disturbance issues in UAH systems, most existent control schemes based on the DOBC method paid much research attention to single type of the disturbance. That is to say, some works aimed to investigate the time-variable bounded disturbances, while the others assumed that the disturbance was strictly generated by an outside system based on the assumption that the information about the disturbance is exactly known [9,22,23,[26][27][28]. It is worth noting that, owing to the complexities of flying environments, only part of the data of outside disturbance can be measured and counted, which can be modeled as an exogenous system, while the rest cannot be modeled but satisfies the bounded time-varying condition.…”

“…Yet, based on available information and statistical data, part of the disturbances can be described by using the outside model, while the rest of the disturbances, although they cannot be modeled, typically satisfy the time-varying bounded condition. Yet, as for the anti-disturbance issue on the UAH system, most existent works have treated the outside disturbance as a unified one and proposed a normal DO or an ESO to derive the estimation and execute the compensation [6][7][8][9][10][11][12], which is available but not effective enough. Therefore, it is more reasonable and meaningful to estimate the disturbances for UAV systems by designing the composite disturbance observers (CBOs), which can greatly improve the efficiency of the compensation and tracking performance [15].…”

“…In recent years, anti-disturbance control has drawn much attention from many researchers. In particular, among these proposed methods, because the disturbance observerbased control (DOBC) estimates the disturbance and compensates it in a feedforward manner, it has been widely utilized to tackle anti-disturbance control for UAH systems since it can effectively eliminate the disturbance without sacrificing control performance [6][7][8][9][10][11][12]. It is worth noting that, according to the channel where the disturbance occurs, the disturbances in UAH system can be divided into matched disturbances and mismatched ones.…”

“…On the other hand, since the mismatched disturbance does not exist in the control channel, it cannot be completely suppressed by an anti-disturbance controller. In [9], as for mismatched random disturbance, its influence was suppressed by combining a nonlinear DOBC and feedback control. In [10], a finite-time DO was designed to tackle the mismatched disturbance.…”

Full State Constrained Flight Tracking Control for Helicopter Systems with Disturbances

“…For these reasons, the anti-disturbance control is adopted based on the disturbance-observer-based control scheme to solve the robust control issue for helicopter systems. In our past works [16,17], the multiple random disturbances were discussed for helicopter nonlinear systems using composite anti-disturbance control schemes. Therefore, the anti-disturbance control issues are solved for helicopters, which would promote the control performance of the flight controller.…”