Adaptive fault-tolerant control for hybrid attitude tracking control system with quantized control torque and measurement

Author(s):  
Min Li ◽  
Yingchun Zhang ◽  
Yunhai Geng

In this paper, the problem of fault tolerant control for spacecraft attitude tracking control system in the presence of actuator faults/failures, quantized control torque and measurement, uncertain inertial matrix and external disturbances is taken into account. The dynamical uniform quantizers are developed to quantize the signals of control torque and measurement, which can reduce the data transmission rate. In combination with the CA and FTC technique, a robust adaptive fault tolerant control scheme is proposed to cope with the effects of quantization errors in control torque and measurement, the unknown actuator faults/failures, uncertain inertial matrix and external disturbances. The developed control strategy combined with quantized control torque and measurement can guarantee the stability of overall closed-loop system and achieve satisfactory attitude tracking performance. Finally, simulation results are presented to verify the effectiveness of the proposed methods.

Author(s):  
Dinesh D Dhadekar ◽  
S E Talole

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.


Author(s):  
Bing Huang ◽  
Ai-jun Li ◽  
Yong Guo ◽  
Chang-qing Wang ◽  
Jin-hua Guo

This paper investigates the finite-time attitude tracking control problem for spacecraft in the presence of external disturbances and actuator faults. Two anti-unwinding attitude tracking control schemes have been proposed based on the rotation matrix and sliding mode control technology. Utilizing a fast terminal sliding mode surface, the first controller can fulfill the finite-time attitude tracking control task with disturbance rejection ability. The second controller can improve the system reliability when the actuator fault occurs. Rigorous mathematical analysis and proof concludes that the proposed controllers can make a spacecraft track the desired attitude command in finite time. Numerical simulation results are presented to demonstrate the effectiveness of the proposed controllers.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Chao Tan ◽  
Guodong Xu ◽  
Limin Dong ◽  
Han Zhao ◽  
Jun Li ◽  
...  

In this paper, we focus on solving the problems of inertia-free attitude tracking control for spacecraft subject to external disturbance, unknown inertial parameters, and actuator faults. The robust control architecture is designed by using the rotation matrix and neural networks. In the presence of external disturbance and parametric uncertainties, a fault-tolerant control (FTC) scheme synthesized with the minimum-learning-parameter (MLP) algorithm is proposed to improve the reliability of the system when unknown actuator faults occur. These methods are developed based on backstepping to ensure that finite-time convergence is achievable for the entire closed-loop system states with low computational complexity. The validity and advantage of the designed controllers are highlighted by using Lyapunov-based analysis. Finally, the simulation results demonstrate the satisfactory performance of the developed controllers.


Author(s):  
Syed Muhammad Amrr ◽  
M Nabi ◽  
Pyare Mohan Tiwari

This paper investigates the application of an integral sliding mode control with a robust nonlinear disturbance observer to obtain an anti-unwinding spacecraft attitude tracking response with robustness against external disturbances, inertia matrix uncertainties, and actuator faults. In the controller design, external disturbances, uncertainties, and actuator faults are lumped together and estimated by the robust nonlinear disturbance observer. The proposed robust nonlinear disturbance observer guarantees the convergence of estimated lumped disturbance error to origin in finite time. The estimated disturbance is then used in the controller as a feed-forward compensator. Further, an adaptive law is also incorporated in the proposed controller to ensure additional robustness. The stability of the overall system and anti-unwinding characteristic are proved using the Lyapunov stability theory. Finally, numerical simulation analysis is performed in the presence of all the sources of lumped disturbances. It is observed that the proposed control strategy is ensuring higher accuracy, good steady-state precision, and eliminates the unwinding phenomenon.


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