Anti-Unwinding Attitude Control with Fixed-Time Convergence for a Flexible Spacecraft

This paper investigates the fixed-time attitude tracking control problem for flexible spacecraft with unknown bounded disturbances. First, with the knowledge of norm upper bounds of external disturbances and the coupling effect of flexible modes, a novel robust fixed-time controller is designed to deal with this problem. Second, the controller is further enhanced by an adaptive law to avoid the knowledge of norm upper bounds of external disturbances and coupling effect of flexible modes. This control law guarantees the convergence of attitude tracking errors in fixed time where the settling time is bounded by a constant independent of initial conditions. Moreover, the proposed controllers can prevent the unwinding phenomenon. Simulation results are presented to demonstrate the performance of the proposed control scheme.

Download Full-text

Robust backstepping attitude tracking control of an underactuated spacecraft with saturation and time-variant perturbations

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/09544100211015938 ◽

2021 ◽

pp. 095441002110159

Author(s):

Reza Nadafi ◽

Mansour Kabganian

Keyword(s):

Angular Velocity ◽

Tracking Control ◽

Initial Conditions ◽

Large Angle ◽

Closed Loop System ◽

External Disturbances ◽

Asymptotic Stable ◽

Attitude Tracking ◽

Attitude Tracking Control ◽

Invariance Theorem

This study investigated associations of attitude tracking control of an underactuated spacecraft with consideration of saturation and perturbations. A nonsingular attitude tracking control was proposed which did not need limiting initial conditions of the quaternions. The controller was analyzed based on Lyapunov criteria and LaSalle’s invariance theorem in the large-angle maneuver. In order to control, the complete kinematic and dynamic model of the underactuated spacecraft was reconstructed. According to simulation results, our controller has excellent robustness against the hard saturation, external disturbances, time-varying inertia uncertainties, and internal disturbances of actuators. As result, we found that the attitude controller was asymptotically stable under the soft saturation and the perturbations so that quaternions and angular velocity converged to the desired path within the 80 s. Also, it was still asymptotic stable under the hard saturation whose level is equal to 0.035 Nm, 3.5% of the soft saturation level. In this case, errors of quaternions and angular velocity were converged to the origin within the 150 s. Finally, the closed-loop system was verified by Adams-MATLAB co-simulation. The maximum verification errors for quaternions were less than 19%, while the maximum verification errors for angular velocity were less than 13.5%.

Download Full-text

Finite time attitude tracking control of an autonomous airship

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331216658947 ◽

2016 ◽

Vol 40 (1) ◽

pp. 155-162 ◽

Cited By ~ 13

Author(s):

Yueying Wang ◽

Pingfang Zhou ◽

Ji-An Chen ◽

Dengping Duan

Keyword(s):

Finite Time ◽

Attitude Control ◽

Tracking Control ◽

Feedback Linearization ◽

Sliding Mode ◽

Uncertain System ◽

External Disturbances ◽

Attitude Tracking ◽

System Uncertainties ◽

Attitude Tracking Control

The problem of station-keeping attitude tracking control for an autonomous airship with system uncertainties and external disturbances is investigated. Adaptive laws are applied to estimate the upper bounds of uncertainties and disturbances, and a nonlinear finite time control scheme is proposed by combing input/output feedback linearization with integral sliding mode technique. Different from the existing works on attitude control of airship, the developed controller can guarantee the yaw, pitch and roll angle trajectories track the desired attitude in finite time in spite of uncertain system uncertainties and external disturbances. Simulation results are provided to illustrate the attitude tracking performance.

Download Full-text

Adaptive Fixed-Time Nonsingular Terminal Sliding Mode Attitude Tracking Control for Spacecraft with Actuator Saturations and Faults

International Journal of Aerospace Engineering ◽

10.1155/2021/8838784 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Zhiguo Han ◽

Minghao Wang ◽

Xunliang Yan ◽

Hang Qian

Keyword(s):

Control Method ◽

Actuator Saturation ◽

Fault Tolerant ◽

Sliding Mode ◽

Fixed Time ◽

External Disturbances ◽

Terminal Sliding Mode ◽

Nonsingular Terminal Sliding Mode ◽

Attitude Tracking ◽

Attitude Tracking Control

This paper focuses on the potential actuator failures of spacecraft in practical engineering applications. Aiming at the shortcomings and deficiencies in the existing attitude fault-tolerant control system design, combined with the current research status of attitude fault-tolerant control technology, we carry out high-precision, fast-convergent attitude tracking algorithms. Based on the adaptive nonsingular terminal sliding mode control theory, we design a kind of fixed-time convergence control method. This method solves the problems of actuator faults, actuator saturation, external disturbances, and inertia uncertainties. The control method includes control law design and controller design. The designed fixed-time adaptive nonsingular terminal sliding mode control law is applicable to the development of fixed-time fault-tolerant attitude tracking controller with multiple constraints. The designed controller considers the saturation of the actuator output torque so that the spacecraft can operate within the saturation magnitude without on-line fault estimation. Lyapunov stability analysis shows that under multiple constraints such as actuator saturation, external disturbances, and inertia uncertainties, the controller has fast convergence and has good fault tolerance to actuator fault. The numerical simulation shows that the controller has good performance and low-energy consumption in attitude tracking control.

Download Full-text

Robust fault-tolerant flight control of quadrotor against faults in multiple motors

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410021999547 ◽

2021 ◽

pp. 095441002199954

Author(s):

Dinesh D Dhadekar ◽

S E Talole

Keyword(s):

Flight Control ◽

Tracking Control ◽

Fault Tolerant ◽

External Disturbances ◽

Detection And Identification ◽

Attitude Tracking ◽

Fault Detection And Identification ◽

Attitude Tracking Control ◽

Disturbance Estimator

In this article, position and attitude tracking control of the quadrotor subject to complex nonlinearities, input couplings, aerodynamic uncertainties, and external disturbances coupled with faults in multiple motors is investigated. A robustified nonlinear dynamic inversion (NDI)-based fault-tolerant control (FTC) scheme is proposed for the purpose. The proposed scheme is not only robust against aforementioned nonlinearities, disturbances, and uncertainties but also tolerant to unexpected occurrence of faults in multiple motors. The proposed scheme employs uncertainty and disturbance estimator (UDE) technique to robustify the NDI-based controller by providing estimate of the lumped disturbance, thereby enabling rejection of the same. In addition, the UDE also plays the role of fault detection and identification module. The effectiveness and benefits of the proposed design are confirmed through 6-DOF simulations and experimentation on a 3-DOF Hover platform.

Download Full-text