Fault Tolerant Attitude Control Scheme Research Articles

Fault-Tolerant Attitude Control Incorporating Reconfiguration Control Allocation for Supersonic Tailless Aircraft

This paper presents a fault-tolerant attitude control scheme, incorporating reconfiguration control allocation for supersonic tailless aircraft subject to nonlinear characteristics, actuator constraint, uncertainty, and actuator faults. The main idea is to propose an incremental reconfiguration closed-loop control allocation scheme, coupled with a basic backstepping attitude controller, to achieve attitude control. Based on the virtual control input generated by the basic backstepping attitude controller, firstly, the incremental nonlinear control allocation method is adopted to deal with the nonlinear characteristics and actuator constraint. Secondly, a distribution error feedback loop is constructed in the incremental nonlinear control allocation method to enhance the robustness against the uncertainty of the control effectiveness matrix. Thirdly, the control effectiveness matrix is reconstructed by different kinds of fault information to deal with actuator faults, and the proper combination of actuator deflections is generated to achieve accurate command tracking. The stability of the proposed scheme is guaranteed by the Jury stability criterion and the Lyapunov stability analysis. Finally, in comparison with the three existing approaches, the simulation results of two cases are provided to show the effectiveness of the proposed scheme.

Fixed-time observer based fault tolerant attitude control for reusable launch vehicle with actuator faults

This paper focuses on the fault tolerant attitude control problem for the reusable launch vehicle (RLV) with model uncertainties, external disturbances and actuator failures/faults during the reentry phase. First, the kinematics and dynamics of the RLV are presented, and the control-oriented mode subject to actuator malfunction is established. Next, a novel fixed-time observer is designed to estimate the compound disturbances, including failure information and uncertainties. Specifically, the proposed observer can guarantee the estimation errors converging to zero within a settling time, which is independent with the system initial conditions. Based on the proposed observer, a finite-time fault tolerant attitude control scheme is developed based on the nonsingular terminal sliding mode technology, which would improve the reentry attitude tracking performance and ensure the finite-time stability of the closed-loop attitude control system even in presence of the actuator faults. Finally, the effectiveness of the proposed method is demonstrated by numerical simulations.

Finite Time Convergence Incremental Nonlinear Dynamic Inversion-Based Attitude Control for Flying—Wing Aircraft with Actuator Faults

In this paper, a two-loop fault-tolerant attitude control scheme is proposed for flying-wing aircraft with actuator faults. A regular nonlinear dynamic inversion (NDI) control is used in the outer attitude loop, and a finite time convergence incremental nonlinear dynamic inversion (FINDI) control combined with control allocation strategy is used in the inner angular rate loop. Prescribed performance bound (PPB) is designed to constrain the tracking errors within a residual set, so the prescribed system performance can be guaranteed. An optimal anti-windup (AW) compensator is introduced to solve the actuator saturation problem. Simulation results demonstrate the effectiveness of the proposed approach.

Fault-tolerant attitude tracking control of combined spacecraft with reaction wheels under prescribed performance

Capture and control of a failed spacecraft can be achieved by a space manipulator installed in a service spacecraft. After this target has been captured, the combined spacecraft must be controlled in a prescribed way. The attitude attacking control of the combined spacecraft system is one major challenge since the mass properties of the whole spacecraft system and configuration matrix of the reaction wheels change, especially when actuator fault occurs. In this paper, a nonlinear disturbance-observer-based fault-tolerant attitude control scheme is developed for the combined spacecraft with prescribed performance. Firstly, an approach is given to reconstruct the attitude tracking dynamics of the combined spacecraft with reaction wheels. Then, a fault-tolerant controller, based on dynamic surface method and nonlinear extended state observer, is developed whereby performance in the light of convergence time, stability and accuracy with inertia uncertainty, actuator saturation and external disturbance can be prescribed. Finally, comparative simulations in both actuator faults and actuator fault-free cases are conducted to show the superiority of the developed attitude tracking control method.

Compound fault-tolerant attitude control for hypersonic vehicle with reaction control systems in reentry phase

In this paper, a novel compound fault-tolerant attitude control (FTC) scheme is proposed for reentry hypersonic vehicles with aerodynamic surfaces and reaction control systems (RCS) in the presence of parameter uncertainties, external disturbances and aerodynamic surfaces faults. Aerodynamic surfaces work as the primary actuators and RCS serve as auxiliary actuators. When aerodynamic surfaces cannot provide the required attitude control torque due to low dynamic pressure or faults, RCS are activated to assist aerodynamic surfaces to generate the residual torque. A nonlinear disturbance observer-based sliding mode controller is designed to calculate the required attitude control torque which can handle the parametric uncertainties and external disturbances together. The quadratic programming method is applied to obtain the optimal aerodynamic surfaces deflections from the required control torque. An innovative fuzzy rule-based decision-making system is design to solve the RCS control allocation problem, which is conceptually easy to understand and computationally efficiently compared with existing approaches. Based on quantized control theory, the closed-loop control system stability is rigorously analyzed. Simulation results are given to demonstrate the effectiveness and efficiency of developed FTC scheme.

Finite‐time disturbance observer based integral sliding mode control for attitude stabilisation under actuator failure

This work develops a novel disturbance observer and integral sliding mode technique based fault tolerant attitude control scheme for spacecraft, which is subject to external disturbance torques and actuator failures. More specifically, a simple and novel finite-time disturbance observer is first designed to reconstruct the synthetic uncertainty deriving from actuator failures and disturbances, by which the synthetic uncertainty is also compensated or restricted. Then, an integral sliding mode based finite-time fault tolerant attitude stabilisation controller incorporating with an adjusting law is investigated to ensure the closed-loop attitude control system converge to the stable region in finite time. And also the finite-time stability of the closed-loop attitude control system driven by the proposed attitude control scheme is analysed and proved utilising Lyapunov methodology. Finally, a simulation example for a rigid spacecraft model is carried out to verify the effectiveness and superiority of the proposed attitude control approach.

Continuous finite-time extended state observer based fault tolerant control for attitude stabilization

This work investigates the challenging problem of fast robust fault tolerant attitude control for spacecraft to handle external disturbances, actuator failures and misalignments. More specially, a novel nonsingular terminal sliding mode based finite-time extended state observer is first designed to estimate and compensate for the lumped system faults or uncertainties. And the proposed extended state observer is analysed and proved to be stable in the sense of fast finite-time uniformly ultimately bounded stability. Then, utilizing the techniques of super-twisting and terminal sliding mode control synthetically, a novel continuous attitude control algorithm is developed. The finite-time stability of the closed-loop attitude control system is proved by using a continuously-differentiable, homogeneous and strict Lyapunov function. And also the proposed control scheme is continuous with the property of chattering restraining. Finally, some numerical simulation results are shown to verify the effectiveness and superior performances of the spacecraft attitude stabilization control system driven by the proposed fast robust fault tolerant attitude control scheme.

Robust adaptive fault tolerant attitude control for post-capture non-cooperative targets with actuator nonlinearities

This paper develops an attitude takeover control structure for post-capture non-cooperative targets with actuator nonlinearities and faults. In this paper, the contingent actuator gain faults, deviation faults and the undesirable non-symmetric dead-zone nonlinearities of the actuator are all under consideration. An effective robust adaptive fault tolerant attitude control method is synthesized such that the actuator nonlinearities and faults can be well handled. As a result, the accurate attitude stabilization and tracking are maintained. Moreover, an extended fault tolerant attitude control scheme that can work well in the presence of inaccurate measurement information is proposed. Based on a quadratic Lyapunov function, the proof of the convergence is completed. Simulation results demonstrate the effectiveness and advantages of the proposed method.

Satellite Flatness based Fault Tolerant Control

Applying flat systems technique in attitude fault tolerant control of an under-actuated satellite has been investigated in this article. The main purpose of this study is development and implementation of a new idea in order to recovery of satellite stability and its acceptable performance in actuator fault scenarios. Solving the attitude fault tolerant control problem is based on consideration a realistic assumption which can show the ability of FTC system in managing the fault scenarios. Lose of effectiveness of actuators which could be caused in many of fault scenarios, modeled and simulated by multiplicative model. Thanks to provided new idea in this study it will be proven that, a wide range of actuator fault scenarios with different intense of faults could be managed without need to reconfiguring the main controller. Usage of this idea affects in reducing the volume of main controller computations and provides an appropriate base for its robust designing in other to dealing with systematically fault scenarios. Furthermore, the provided active fault tolerant attitude control scheme uses analytical redundancy system which could be considered as analytical observer. The suggested analytical observer by this technique, which belongs to nonlinear observer category, can observe all of the dynamic variables in allowable range of error. Practical implications of this study belong in this fact which analytical redundancy based on new idea in order to maintaining stability could be a perfect option in different fault scenarios such as systematically uncertainties and sensor faults. Hence this idea could be implemented without need to any physical instrument. General Terms Fault tolerant, flatness based control.