Finite-time Fault-tolerant Control Research Articles

Smooth finite-time fault-tolerant attitude tracking control for rigid spacecraft

This paper investigates the problem of attitude tracking control for a rigid spacecraft subject to parametric uncertainties, external disturbances, actuator faults and actuator saturation constraints. By combining the finite-time passivity technique into adaptive sliding mode control approach, a novel smooth fault-tolerant control algorithm with finite time convergence is proposed. Then, the finite-time convergence of the relative attitude errors will be achieved by implementing the proposed smooth fault-tolerant controller, even under actuator faults and magnitude constraints. In particular, a solution to the unwinding phenomenon, arising from the usage of the redundant four-parameter attitude representation, is explored in the sense of finite-time passivity. Besides detailed controller design procedures and rigorous theoretical proofs of all related closed-loop finite-time stability, numerical simulation results are exhibited to demonstrate the effectiveness and superior control performance of the proposed control scheme.

Finite Time Fault Tolerant Control for Robot Manipulators Using Time Delay Estimation and Continuous Nonsingular Fast Terminal Sliding Mode Control.

In this paper, a novel finite time fault tolerant control (FTC) is proposed for uncertain robot manipulators with actuator faults. First, a finite time passive FTC (PFTC) based on a robust nonsingular fast terminal sliding mode control (NFTSMC) is investigated. Be analyzed for addressing the disadvantages of the PFTC, an AFTC are then investigated by combining NFTSMC with a simple fault diagnosis scheme. In this scheme, an online fault estimation algorithm based on time delay estimation (TDE) is proposed to approximate actuator faults. The estimated fault information is used to detect, isolate, and accommodate the effect of the faults in the system. Then, a robust AFTC law is established by combining the obtained fault information and a robust NFTSMC. Finally, a high-order sliding mode (HOSM) control based on super-twisting algorithm is employed to eliminate the chattering. In comparison to the PFTC and other state-of-the-art approaches, the proposed AFTC scheme possess several advantages such as high precision, strong robustness, no singularity, less chattering, and fast finite-time convergence due to the combined NFTSMC and HOSM control, and requires no prior knowledge of the fault due to TDE-based fault estimation. Finally, simulation results are obtained to verify the effectiveness of the proposed strategy.

Finite-time fault-tolerant control for flutter involving control delay

Many control laws, such as optimal controllers and classical controllers, have seen their applications to suppressing the aeroelastic vibrations of the aeroelastic system. However, those control laws may not work effectively if the aeroelastic system involves control delay and faults. In this paper, we use the finite-time H∞ adaptive fault-tolerant control technique to deal with the flutter problem of the wing, which is subject to control delay, parameter uncertainties and external disturbances. Then actuator faults are considered in the control design. The theory content of this article includes the modeling of wing flutter and fault-tolerant controller design. By using the Lyapunov–Krasovskii function and the linear matrix inequality (LMI), the stability of the finite-time H∞ adaptive fault-tolerant controller is theoretically proved. Simulation results are given to demonstrate the effectiveness of the scheme.

Finite-time fault-tolerant control for flutter of wing

In this paper, we use the radial basis function neural network and the finite-time H∞ adaptive fault-tolerant control technique to deal with the flutter problem of wings with propulsion system, which is affected by input saturation, time delay, time-varying parameter uncertainties and external disturbances. Then sensor and actuator faults are both considered in the control design. The theory content of this article includes the trajectory optimization, modeling of wing flutter and fault-tolerant controller design. The stability of the finite-time H∞ adaptive fault-tolerant controller is theoretically proved. Finally, simulation results are given to demonstrate the effectiveness of the scheme.

Finite-time fault tolerant control of uncertain singular Markovian jump systems with bounded transition probabilities

This paper is concerned with the problem of finite-time fault-tolerant control for one family of uncertain singular Markovian jump with bounded transition probabilities and nonlinearities systems. The actuator faults are presented as a more general and practical continuous fault model. Partially known transition rate parameters have given lower and upper bounds. Firstly, the resulting closed-loop error system is constructed based on a state estimator; sufficient criteria are provided to guarantee that the augmented system has singular stochastic finite-time boundedness and singular stochastic $$H_\infty $$ finite-time boundedness in both normal and fault cases. Then, by employing a decoupling technique, the gain matrices of state feedback controller and state estimator are achieved by solving a feasibility problem in terms of linear matrix inequalities with a fixed parameter, respectively. Finally, numerical examples are given to demonstrate the effectiveness of the proposed design approach.

Finite-time fault-tolerant attitude stabilization for spacecraft with actuator saturation

This paper addresses the finite-time fault-tolerant attitude stabilization control problem for a rigid spacecraft in the presence of actuator faults or failures, external disturbances, and modeling uncertainties. First, a basic fault-tolerant controller is proposed to accommodate actuator faults or failures and guarantee local finite-time stability. When there is no a priori knowledge of actuator faults, disturbances, and inertia uncertainties, an online adaptive law is proposed to estimate the bounds of these uncertainties, and local finite-time convergence is achieved by an adaptive fault-tolerant controller. In addition, another adaptive fault-tolerant control scheme is derived that explicitly takes into account the actuator saturation. The proposed attitude controller provides fault-tolerant capability despite control input saturation and ensures that attitude and angular velocity converge to a neighborhood of the origin in finite time. Finally, simulation studies are presented to demonstrate the effectiveness of the proposed method.

Adaptive fuzzy finite-time fault-tolerant attitude control of rigid spacecraft

This paper presents the finite-time adaptive fuzzy control to regulate thruster faults in rigid spacecraft system. The considered faults are that the thrusters losing power partially or even totally. Fuzzy logic systems are used to approximate the unknown nonlinear function which is produced by the external disturbances, unknown inertia matrix and thrusters faults. Uniting fast nonsingular terminal sliding mode surface (FNTSMS) and the fault-tolerant control (FTC), two novel adaptive fuzzy finite-time FTC schemes are developed. It has been testified that this control method can make sure that the rigid spacecraft has excellent property of fault-tolerant and all the signals are finite-time convergence. Simulation examples on a rigid body spacecraft with three thrusters and six thrusters are done to indicate that the finite-time FTC schemes are available in achieving high attitude tracking with faults and uncertainty of the system.

Finite-time fault tolerant attitude stabilization control for rigid spacecraft

A sliding mode based finite-time control scheme is presented to address the problem of attitude stabilization for rigid spacecraft in the presence of actuator fault and external disturbances. More specifically, a nonlinear observer is first proposed to reconstruct the amplitude of actuator faults and external disturbances. It is proved that precise reconstruction with zero observer error is achieved in finite time. Then, together with the system states, the reconstructed information is used to synthesize a nonsingular terminal sliding mode attitude controller. The attitude and the angular velocity are asymptotically governed to zero with finite-time convergence. A numerical example is presented to demonstrate the effectiveness of the proposed scheme.