Robust Attitude Control Scheme Research Articles

Robust Attitude Control Scheme for Constantly Spinning Small-Sized Quadrotor in the Presence of Imbalance Characteristics

Unlike normal yaw motion, a constantly spinning quadrotor experiences severe instability while rotating at high angular speeds owing to its imbalancecharacteristics originating from the off-center parts. To resolve this issue, this study proposes a novel composite robust control scheme for a constantly spinning quadrotor, with the aim to achieving omnidirectional sensing by scanning its surroundings with a single field of view limited sensor. The proposed scheme makes use of both offline calibration and online disturbance observation to compensate for the variation in the center of mass and misalignment between the body-fixed frame and principal axis of rotation, respectively. Additionally, the reference inputs are reshaped, or leading in time, to achieve the desired flying direction. It is demonstrated through an experiment that the proposed control scheme compensates well for the effect of the imbalance characteristics of the quadrotor, thus achieving good omnidirectional sensing with more stable rotation.

측정 민감도 및 외란 하에서 쿼드로터의 강인 자세 제어

A robust attitude control scheme for quadrotor is proposed under measurement sensitivity and external disturbance. In order to treat measurement sensitivity, a new determination process of a compact with allowed measurement sensitivity is presented by utilizing Lyapunov equation. With our control scheme, all controlled system states are shown to be bounded. Moreover, the ultimate bounds of all states can be made arbitrarily small by adjusting the gain-scaling factor in the presence of external disturbance. The validity of our control method is first checked via simulation, and then is also experimentally shown in the attitude control of quadrotor system.

Invariant set based sliding mode control for near-space vehicles with attitude constraints

In this article, a robust attitude control scheme, which is called sliding mode control with unidirectional auxiliary surfaces (UAS-SMC), is proposed for the near-space vehicle with attitude constraints and time-varying unknown disturbance. Firstly, the positively invariant sets are designed with the UAS-SMC method. The invariant property of these sets can be utilized to guarantee the attitude constraints. Secondly, a UAS nonlinear disturbance observer is firstly developed for the NSV with time-varying unknown disturbance. By introducing the information of UAS surfaces, the performance of this observer is enhanced. The convergence of all closed-loop signals is rigorously proved via Lyapunov analysis method under the developed robust UAS-SMC scheme. Finally, simulation results are given to illustrate the effectiveness of the proposed attitude control scheme.

Robust Adaptive Attitude Control for Airbreathing Hypersonic Vehicle with Attitude Constraints and Propulsive Disturbance

A robust adaptive backstepping attitude control scheme, combined with invariant-set-based sliding mode control and fast-nonlinear disturbance observer, is proposed for the airbreathing hypersonic vehicle with attitude constraints and propulsive disturbance. Based on the positive invariant set and backstepping method, an innovative sliding surface is firstly developed for the attitude constraints. And the propulsive disturbance of airbreathing hypersonic vehicle is described as a differential equation which is motivated by attitude angles in this paper. Then, an adaptive fast-nonlinear disturbance observer for the proposed sliding surface is designed to estimate this kind of disturbance. The convergence of all closed-loop signals is rigorously proved via Lyapunov analysis method under the developed robust attitude control scheme. Finally, simulation results are given to illustrate the effectiveness of the proposed attitude control scheme.

Terminal Sliding Mode Control with Unidirectional Auxiliary Surfaces for Hypersonic Vehicles Based on Adaptive Disturbance Observer

A novel flight control scheme is proposed using the terminal sliding mode technique, unidirectional auxiliary surfaces and the disturbance observer model. These proposed dynamic attitude control systems can improve control performance of hypersonic vehicles despite uncertainties and external disturbances. The terminal attractor is employed to improve the convergence rate associated with the critical damping characteristics problem noted in short-period motions of hypersonic vehicles. The proposed robust attitude control scheme uses a dynamic terminal sliding mode with unidirectional auxiliary surfaces. The nonlinear disturbance observer is designed to estimate system uncertainties and external disturbances. The output of the disturbance observer aids the robust adaptive control scheme and improves robust attitude control performance. Finally, simulation results are presented to illustrate the effectiveness of the proposed terminal sliding mode with unidirectional auxiliary surfaces.

Guaranteed transient performance based control with input saturation for near space vehicles

This paper describes the design of guaranteed transient performance based attitude control for the near space vehicle (NSV) with control input saturation using the backstepping method. To improve the robust controllability of the NSV, the parameter adaptive method is used to tackle the integrated effect of unknown time-varying disturbance and control input saturation. Based on the backstepping technique and parameter estimated outputs, a robust attitude control scheme is proposed for the NSV with input saturation. A novel robust attitude control scheme is then proposed based on a prescribed performance bound (PPB) which characterizes the convergence rate and maximum overshoot of the attitude tracking error. The closed-loop system stability under both the developed robust attitude control schemes is proved using Lyapunovs method and uniformly asymptotical convergence of all closed-loop signals is guaranteed. Finally, simulation results are given to show the effectiveness of both the proposed robust constrained attitude control schemes.

Robust attitude control of near space vehicles with time-varying disturbances

In this paper, the robust attitude control scheme is developed for near space vehicles (NSVs) with time-varying disturbances based on backstepping technique. To efficiently handle the time-varying disturbance and the system uncertainty, the disturbance observer is employed to estimate them. Using backstepping technique and the disturbance observer output, the robust attitude control is firstly developed for the NSV. And then, considering the actuator dynamics, another robust attitude control scheme is proposed for the NSV based on the disturbance observer. The uniformly ultimate bounded-ness of all closed-loop signals are guaranteed via Lyapunov analysis under both developed robust attitude control schemes. Finally, simulation results are presented to illustrate the effectiveness of the proposed attitude control schemes.