Actuator Fault-tolerant Control Scheme Research Articles

Fault-tolerant control based on 2D game for independent driving electric vehicle suffering actuator failures

This paper proposes a cooperative game-based actuator fault-tolerant control strategy for a four-wheel independent drive electric vehicle with an active front steering system. For achieving fault-tolerant control and targets cooperation, a two-dimensional game strategy is proposed to balance the stability and economy. The first-dimensional game is utilized to determine the dominant control target of the actuator, then the second-dimensional game is employed to assign the fault-tolerant control task for the remaining healthy actuators. The two dimensions are integrated based on the linear quadratic differential game theory, and a hybrid weighted Pareto frontier is thus established. A Shapley value based weight calculation method is proposed to obtain a set of fair and unique weights according to the importance of each player, which makes the solution of the optimal control problem more easily obtained. The effectiveness and real-time performance of the control strategy are tested under different scenarios. The simulation results demonstrate that the proposed strategy can balance the stability and economy well, outperforms the traditional method in terms of target tracking performance. For special case, the response of the yaw rate could be improved up to 39.83% comparing to that of the linear quadratic regulator method.

Adaptive actuator fault-tolerant control for a three-dimensional Euler–Bernoulli beam with output constraints and uncertain end load

This paper studied an adaptive actuator fault-tolerant control scheme for the flexible Euler–Bernoulli beam in the three-dimensional space with output constraints and uncertain end load. The dynamic models are represented by partial differential equations (PDEs) and ordinary differential equations (ODEs). When part of the actuator fails, an adaptive control scheme is designed to regulate the vibration and stabilize the flexible three-dimensional Euler–Bernoulli beam. Barrier Lyapunov Function (BLF) is adopted to realize output constraints of the system. Adaptive control law with projection mapping operator is designed to compensate for the end load which is uncertain and bounded. The goal of this paper is to suppress the displacement of the flexible three-dimensional Euler–Bernoulli beam which can be constrained in given bounds under actuator fault and uncertain, bounded end load. It is confirmed that the proposed control scheme can deal with the vibration, adaptive actuator fault-tolerant control, uncertain and bounded end load and output constraints of the system simultaneously. Finally, numerical simulations illustrate the effectiveness and feasibility of the method.

Design and real-time implementation of actuator fault-tolerant control for differential-drive mobile robots based on multiple-model approach

In this article, an actuator fault-tolerant control scheme is proposed for differential-drive mobile robots based on the concept of multiple-model approach. The nonlinear kinematic model of the differential-drive mobile robot is discretized and a bank of extended Kalman filters is designed to detect, isolate, and identify actuator faults. A fault-tolerant controller is then developed based on the detected fault to accommodate its effect on the trajectory-tracking performance of the mobile robot. Extensive experimental results are presented to demonstrate the efficacy of the proposed fault-tolerant control approach.

Actuator Fault Tolerant Control: A Receding Horizon Set-Theoretic Approach

In this note, a novel actuator Fault Tolerant Control strategy for constrained discrete time linear systems subject to bounded disturbances is proposed. The scheme consists of three modules: a bank of estimators, each one associated with healthy and faulty model configurations, a logic mechanism for identifying healthy-to-faulty and faulty-to-healthy transitions and an estimate based control reconfiguration unit. The idea is to abstractly describe healthy and faulty plant configurations by means of a switching paradigm and sequences of pre-computed inner approximations of one-step controllable sets. Such regions are then on-line exploited together with a switching logic to determine the current plant configuration on the basis of the state estimate provided by the observers.

Set-based Fault-Tolerant Control of Convex Polytopic LPV Systems using a Bank of Virtual Actuators

We propose a robust actuator fault tolerant control strategy for systems with linear parameter varying (LPV) uncertainty model description. The scheme employs a set-based robust fault detection and identification (FDI) approach and a bank of virtual actuators (VA). An interesting feature is that the virtual actuators are used both for FDI and controller reconfiguration (CR) tasks. The robust FDI method is based on the separation of relevant sets defined for measurable residual signals, which are computed based on the virtual actuator signals and taking into account model uncertainty, noises and process disturbances. For CR, each VA is designed to operate adequately in combination with a nominal controller (designed for the fault-free plant) to achieve correct reconfiguration for a particular fault situation in a considered range of fault scenarios. The resulting robust fault tolerant control scheme ensures boundedness of the closed-loop system trajectories under a wide range of actuator fault scenarios. The performance of the scheme is illustrated through a simulation example.

An Actuator Failure Tolerant Control Scheme for an Underwater Remotely Operated Vehicle

This paper proposes an actuator fault-tolerant control scheme, composed of the usual modules performing detection, isolation, accommodation, designed for a class of nonlinear systems, and then applied to an underwater remotely operated vehicle (ROV) used for inspection purposes. Detection is in charge of a residual generation module, while a sliding-mode-based approach has been used both for ROV control and fault isolation, after the application of an input decoupling nonlinear state transformation to the ROV model. Finally, control reconfiguration is performed exploiting the inherent redundancy of actuators. An extensive simulation study has been also performed, supporting the effectiveness of the proposed approach.

Bank of Virtual Actuators for Fault Tolerant Control

AbstractWe propose an actuator fault tolerant control scheme based on a bank of virtual actuators (VA), with the novel feature that the virtual actuators implicitly integrate both fault detection and isolation (FDI) and controller reconfiguration (CR) tasks. The bank of VAs operates in closed-loop with an observer-based tracking controller designed for a nominal (fault free) model of the plant. We consider abrupt actuator faults ranging over a finite cover. Each VA is designed to operate appropriately in combination with the nominal controller to achieve correct CR for a particular fault situation in the considered range. A switching rule that engages the suitable VA from the bank is based on sets defined for measurable residual signals constructed directly from the virtual actuators signals. The overall scheme is shown to guarantee closed-loop boundedness and setpoint tracking under all considered fault situations. The method is applied to an example of aircraft lateral control.

Robust MPC multicontroller design for actuator fault tolerance of constrained systems

AbstractIn this paper, we present a robust actuator fault-tolerant control strategy for constrained linear systems, in the presence of bounded state and output disturbances. The scheme is based on a bank of state estimators which match different fault situations that can occur in the system. A fault detection and isolation (FDI) unit verifies that suitable residual variables lie inside pre-computed sets and selects the estimate that matches the current plant behaviour. A bank of robustly stabilising tube-based MPC control laws is designed, each associated to a fault scenario and the appropriate controller is selected among them using the information provided by the FDI module. By means of “tubes” of trajectories, we ensure robust closed-loop exponential stability of the constrained system and good performance in the fault-free case and under the occurrence of abrupt actuator faults.

Observer-based Fault Tolerant Sliding Mode Control for Remotely Operated Vehicles

Abstract This paper proposes an actuator fault-tolerant control scheme designed for a class of nonlinear systems, and then applied to an underwater Remotely Operated Vehicle (ROV) used for inspection purposes. Fault detection is achieved using a Variable Structure System (VSS) observer, while a sliding-mode based approach has been used both for fault isolation and ROV control, after the application of an input decoupling nonlinear state transformation to the ROV model. Finally, control reconfiguration is performed exploiting the inherent redundancy of actuators. An extensive simulation study has been also performed, supporting the effectiveness of the proposed approach.

Actuator Failure Tolerant Control Design for Underwater Remotely Operated Vehicles

This paper proposes an actuator fault-tolerant control scheme, composed of the usual modules performing detection, isolation, accommodation, designed for a class of nonlinear systems, and then applied to an underwater remotely operated vehicle (ROV) used for inspection purposes. Detection is in charge of a residual generation module, while a sliding-mode based approach has been used both for ROV control and fault detection, after the application of an input decoupling nonlinear state transformation to the ROV model. Finally, control reconfiguration is performed exploiting the inherent redundancy of actuators. An extensive simulation study has been also performed, supporting the effectiveness of the proposed approach.

Invariant set approach to actuator fault tolerant control

We present a new actuator fault-tolerant control strategy based on the separation of sets that characterise healthy system operation from sets that characterise faulty operation. The new scheme is an extension of a similar strategy recently proposed by the authors. In the present paper we propose a new criterion for fault detection and isolation that leads to less conservative conditions for fault tolerant closed-loop stability. These new conditions employ discrete-time models for the plant, reference system and observers and allow for quicker fault detection and consequent reconfiguration of the controller.