scholarly journals Sliding Mode Thau Observer for Actuator Fault Diagnosis of Quadcopter UAVs

2018 ◽  
Vol 8 (10) ◽  
pp. 1893 ◽  
Author(s):  
Ngoc Phi Nguyen ◽  
Sung Kyung Hong
Keyword(s):  
Fault Diagnosis ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
State Equation ◽  
Linear Matrix ◽  
Time Variability ◽  
Actuator Faults ◽  
External Disturbances ◽  
Aerial Vehicle ◽  
Diagnosis Method

Fault diagnosis (FD) is one of the main roles of fault-tolerant control (FTC) systems. An FD should not only identify the presence of a fault, but also quantify its magnitude and location. In this work, we present a robust fault diagnosis method for quadcopter unmanned aerial vehicle (UAV) actuator faults. The state equation of the quadcopter UAV is examined as a nonlinear system. An adaptive sliding mode Thau observer (ASMTO) method is proposed to estimate the fault magnitude through an adaptive algorithm. We then obtain the design matrices and parameters using the linear matrix inequalities (LMI) technique. Finally, experimental results are presented to show the advantages of the proposed algorithm. Unlike previous research on quadcopter UAV FD systems, our study is based on ASMTO and can, therefore, determine the time variability of a fault in the presence of external disturbances.

A fault-tolerant attitude tracking control of spacecraft using an anti-unwinding robust nonlinear disturbance observer

2019 ◽  
Vol 233 (16) ◽  
pp. 6005-6018 ◽  
Author(s):  
Syed Muhammad Amrr ◽  
M Nabi ◽  
Pyare Mohan Tiwari
Keyword(s):  
Disturbance Observer ◽  
Controller Design ◽  
Simulation Analysis ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Actuator Faults ◽  
External Disturbances ◽  
Nonlinear Disturbance Observer ◽  
Attitude Tracking ◽  
Nonlinear Disturbance

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.

scholarly journals Active Fault-Tolerant Control of a Quadcopter against Time-Varying Actuator Faults and Saturations Using Sliding Mode Backstepping Approach

2019 ◽  
Vol 9 (19) ◽  
pp. 4010 ◽  
Author(s):  
Ngoc Phi Nguyen ◽  
Sung Kyung Hong
Keyword(s):  
Fault Diagnosis ◽  
Active Fault ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Lyapunov Theory ◽  
Fault Estimation ◽  
Time Varying ◽  
Actuator Faults ◽  
Active Fault Tolerant Control

Fault-tolerant control is becoming an interesting topic because of its reliability and safety. This paper reports an active fault-tolerant control method for a quadcopter unmanned aerial vehicle (UAV) to handle actuator faults, disturbances, and input constraints. A robust fault diagnosis based on the H ∞ scheme was designed to estimate the magnitude of a time-varying fault in the presence of disturbances with unknown upper bounds. Once the fault estimation was complete, a fault-tolerant control scheme was proposed for the attitude system, using adaptive sliding mode backstepping control to accommodate the actuator faults, despite actuator saturation limitation and disturbances. The Lyapunov theory was applied to prove the robustness and stability of the closed-loop system under faulty operation. Simulation results show the effectiveness of the fault diagnosis scheme and proposed controller for handling actuator faults.

scholarly journals Fault Diagnosis and Fault-Tolerant Control Scheme for Quadcopter UAVs with a Total Loss of Actuator

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1139 ◽  
Author(s):  
Ngoc Nguyen ◽  
Sung Hong
Keyword(s):  
Fault Diagnosis ◽  
Active Fault ◽  
Control Method ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Total Loss ◽  
Actuator Faults ◽  
Control Scheme ◽  
Robust Adaptive

Fault-tolerant control has drawn attention in recent years owning to its reliability and safe flight during missions. In this article, an active fault-tolerant control method is proposed to control a quadcopter in the presence of actuator faults and disturbances. Firstly, the dynamics of the quadcopter are presented. Secondly, a robust adaptive sliding mode Thau observer is presented to estimate the time-varying magnitudes of actuator faults. Thirdly, a fault-tolerant control scheme based on sliding mode control and reconfiguration technique is designed to maintain the quadcopter at the desired position despite the presence of faults. Unlike previous studies, the proposed method aims to integrate the fault diagnosis and a fault-tolerant control scheme into a single unit with total loss of actuator. Simulation results illustrate the efficiency of the suggested algorithm.

scholarly journals Actuator-Integrated Fault Estimation and Fault Tolerant Control for Electric Power Steering System of Forklift

2021 ◽  
Vol 11 (16) ◽  
pp. 7236
Author(s):  
Xiangxiang Su ◽  
Benxian Xiao
Keyword(s):  
Electric Power ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Fault Estimation ◽  
Linear Matrix ◽  
Actuator Faults ◽  
Electric Power Steering ◽  
Power Steering ◽  
System States

For the problem of actuator-integrated fault estimation (FE) and fault tolerant control (FTC) for the electric power steering (EPS) system of a forklift, firstly, a dynamic model of a forklift EPS system with actuator faults was established; then, an integrated FE and FTC design was proposed. The nonlinear unknown input observer (NUIO) was proposed to estimate the system states and actuator faults, and an adaptive sliding mode FTC system was constructed based on it. The gain of the observer and controller is obtained by H∞ optimization and one-step linear matrix inequality (LMI) formula operation in order to realize the overall optimal design of an FTC system. Finally, the experimental results show that when actuator failure occurs, the proposed integrated FE and FTC were more accurate than the decentralized design to estimate the system states and the actuator faults. The proposed fault-tolerant controller can more effectively restore the power assist performance of the steering power motor in case of failure and effectively ensure the safety and reliability of the forklift EPS system.

Reconfiguration control method for non-redundant actuator faults on unmanned aerial vehicle

2019 ◽  
Vol 234 (10) ◽  
pp. 1597-1610 ◽  
Author(s):  
Adèle Boche ◽  
Jean-Loup Farges ◽  
Henry De Plinval
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Control Method ◽  
Fault Tolerant ◽  
State Equation ◽  
Actuator Faults ◽  
Actuator Dynamics ◽  
Discounted Cost ◽  
Optimal Controllers ◽  
Control Scheme ◽  
Aerial Vehicle

In this article, an indirect continuous and discrete Fault-Tolerant Control scheme is applied to the longitudinal dynamics of a fixed-wing unmanned aerial vehicle. To address the problem raised by a possible engine fault, the FTC method is adapted to non-redundant actuator faults by considering signatures on residuals, designing discounted cost optimal controllers, using rolling horizon techniques and considering actuator dynamics in the state equation. The efficiency of the proposed approach is demonstrated on a scenario involving thrust and elevon faults during a landing procedure.

scholarly journals A Composite Robust Fault-Tolerant Control Scheme for Limited-Thrust Spacecraft Rendezvous in Near-Circular Orbits

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Neng Wan ◽  
Weiran Yao ◽  
Mingming Shi
Keyword(s):  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Actuator Faults ◽  
External Disturbances ◽  
Circular Orbits ◽  
Control Scheme ◽  
Guaranteed Cost ◽  
Fault Information ◽  
Composite Control Scheme

External perturbations and actuator faults are two practical and significant issues that deserve designers' considerations when synthesizing the controllers for spacecraft rendezvous. A composite robust fault-tolerant control (FTC) scheme that does not require the fault information is proposed in this paper for limited-thrust rendezvous in near-circular orbits. Within the control scheme, a reliable integral sliding mode (ISM) auxiliary controller and a modified guaranteed cost FTC are, respectively, developed to attenuate the external disturbances and to stabilize the nominal rendezvous system with actuator faults. Comparisons with previous works as well as a more practical and challenging simulation example are presented to verify the advantages of this composite control scheme.

scholarly journals A Robust Fault-Tolerant Control for Quadrotor Helicopters against Sensor Faults and External Disturbances

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ban Wang ◽  
Peng Huang ◽  
Wei Zhang
Keyword(s):  
Fault Diagnosis ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Sensor Faults ◽  
External Disturbances ◽  
Quadrotor Helicopter ◽  
Control Scheme ◽  
Control Schemes ◽  
The Stability

This paper presents an active fault-tolerant control strategy for quadrotor helicopters to simultaneously accommodate sensor faults and external disturbances. Unlike most of the existing fault diagnosis and fault-tolerant control schemes for quadrotor helicopters, the proposed fault diagnosis scheme is able to estimate sensor faults while eliminating the effect of external disturbances. Moreover, the proposed fault-tolerant control scheme is capable to eliminate the adverse effect of external disturbances as well by designing a disturbance observer to effectively estimate the unknown external disturbances and integrating with the designed integral sliding-mode controller. In this case, the continuous operation of the quadrotor helicopter is ensured while avoiding the unexpected control chattering. In addition, the stability of the closed-loop system is theoretically proved. Finally, the effectiveness and advantages of the proposed scheme are validated and demonstrated through comparative numerical simulations of the quadrotor helicopter under different faulty and uncertain scenarios.

scholarly journals Robust fault diagnosis and fault-tolerant control for nonlinear quadrotor unmanned aerial vehicle system with unknown actuator faults

2021 ◽  
Vol 18 (2) ◽  
pp. 172988142110027
Author(s):  
Jinjin Guo ◽  
Juntong Qi ◽  
Chong Wu
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Small Amplitude ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Adaptive Observer ◽  
Fault Estimation ◽  
Detection Accuracy ◽  
Actuator Faults ◽  
Model Uncertainties ◽  
Aerial Vehicle

This article addresses the problem that quadrotor unmanned aerial vehicle (UAV) actuator faults, including small-amplitude bias faults and gain degradation, cannot be detected in time. A hybrid observer, which combines the fast convergence from adaptive observer and the strong robustness from sliding mode observer, is proposed to detect and estimate UAV actuator faults accurately with model uncertainties and disturbances. A nonlinear quadrotor UAV model with model uncertainties and disturbances is considered and a more precise unified expression for actuator faults that do not require knowing where the upper or lower bound is provided. The original system is decomposed into two subsystems by coordinate transformation to improve detection accuracy for small amplitude bias faults and avoid external influences. The hybrid observer is then designed to estimate subsystem states and faults with good stability by selecting a Lyapunov function. A fault-tolerant controller is obtained depending on fault estimation by compensating the normal controller (proportion integral differential [PID] controller). Several numerical simulations confirmed that unknown actuator faults can be accurately detected, estimated, and compensated for even under disturbance conditions.

scholarly journals A Robust Fault-Tolerant Predictive Control for Discrete-Time Linear Systems Subject to Sensor and Actuator Faults

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2307
Author(s):  
Sofiane Bououden ◽  
Ilyes Boulkaibet ◽  
Mohammed Chadli ◽  
Abdelaziz Abboudi
Keyword(s):  
Model Predictive Control ◽  
Linear Systems ◽  
Predictive Control ◽  
Robust Stability ◽  
Discrete Time ◽  
Fault Tolerant ◽  
Linear Matrix ◽  
Input Constraints ◽  
Actuator Faults ◽  
Time Linear

In this paper, a robust fault-tolerant model predictive control (RFTPC) approach is proposed for discrete-time linear systems subject to sensor and actuator faults, disturbances, and input constraints. In this approach, a virtual observer is first considered to improve the observation accuracy as well as reduce fault effects on the system. Then, a real observer is established based on the proposed virtual observer, since the performance of virtual observers is limited due to the presence of unmeasurable information in the system. Based on the estimated information obtained by the observers, a robust fault-tolerant model predictive control is synthesized and used to control discrete-time systems subject to sensor and actuator faults, disturbances, and input constraints. Additionally, an optimized cost function is employed in the RFTPC design to guarantee robust stability as well as the rejection of bounded disturbances for the discrete-time system with sensor and actuator faults. Furthermore, a linear matrix inequality (LMI) approach is used to propose sufficient stability conditions that ensure and guarantee the robust stability of the whole closed-loop system composed of the states and the estimation error of the system dynamics. As a result, the entire control problem is formulated as an LMI problem, and the gains of both observer and robust fault-tolerant model predictive controller are obtained by solving the linear matrix inequalities (LMIs). Finally, the efficiency of the proposed RFTPC controller is tested by simulating a numerical example where the simulation results demonstrate the applicability of the proposed method in dealing with linear systems subject to faults in both actuators and sensors.

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