Adaptive Active Fault Tolerant Control for Discrete‐Time Systems with Uncertainties

Abstract

An active fault‐tolerant control scheme for discrete‐time systems is proposed to solve a difficult problem of fault‐tolerant controller design in the presence of partial loss of actuator effectiveness faults and structural parameter uncertainties assumed to be matched, using adaptive control techniques to help a faster and more accurate compensation of failure and uncertainty. An automated fault estimation scheme is developed together with an adaptive model parameter identification to obtain system parameter estimates. With these estimates fed back to the system, a model reference adaptive controller is constructed to achieve a desired tracking performance. Since parameters are obtained and updated online, the control system has an automatic failure compensation capability so as to recognize or reconfigure the control law in real time in response to failure indications. The stability and convergence follow from discrete‐time Lyapunov arguments. Simulation results from the linearized lateral dynamics model of the Boeing 747 airplane are presented to show the efficiency of proposed methods.

Adaptive Fault‐Tolerant Control of Uncertain MIMO Systems with Reduced Requirement on Desired Trajectory Under Unknown Control Direction

“…In all simulations, the initial conditions are selected as x = [0.6, 0; 0.6, 0] T ,â(0) = 0, (0) = 0, the "core" function f (⋅) = ‖x 2 ‖ 2 + ‖x 2 ‖, then the core function for (21) is readily derived as (⋅) = ‖x 2 ‖ 2 + ‖x 2 ‖ + ‖ÿ d ‖ + ‖̇e m ‖. The parameters are chosen as k 2 = 80, 3 Fig. 9 depicts the boundedness and convergence of the tracking errors e 1 and e 2 under the proposed adaptive fault-tolerant control method with the actuation faults.…”

Novel MPC‐Based Fault Tolerant Tracking Control Against Sensor Faults

“…(S1) Solve the LMIs (15) and (16) by LMI solvers to get the matrices Q, Y , S, and further P, H, then the constant parameters of estimator (9) are K = PB and N = PA − HC. (S2) Given the appropriate initial signals: z(0),F(0) > 0, E(0), calculate the time-varying parameter L(0) by (19), and obtain thex(0) andŷ(0) from the last two equations of (9).…”

“…In recent years, the FTC design emphasized on the control performance and physical constraints like the actuator saturation has been studied besides the closed-loop stability, see e.g. [10][11][12][13][14][15][16][17][18]. Indeed, it is practical and very intractable in developing FTC strategy with the performance requirement and system input and output (I/O) constraints from the limitations on physical components, operating circumstance and product quality.…”

Fault-tolerant control for commercial aircraft with actuator faults and constraints

“…Although such as approach doesn't need FE or RC, it has limited fault tolerant capabilities. However, the research on the AFTCS has developed rapidly for structures which contain both FE and RC, bringing significant convenience and potential applications [8][9][10][11][12][13][14].…”

“…In other approaches, the fault was regarded as an additional part of the motion equation and some assumptions were made so that the FE module can provide accurate information. In [12], a robust fault tolerant control scheme was proposed to process actuator faults for uncertain nonlinear systems with zero dynamics, whereas in [13], adaptive control techniques were used to help obtain a faster and more accurate compensation of failure and uncertainty for discretetime systems, solved a problem of fault tolerant controller design in the presence of partial loss of actuator effectiveness faults and the structural parameter uncertainties were assumed to be matched. A novel aircraft trajectory controller with the incremental nonlinear dynamic inversion to achieve fault tolerant trajectory control was proposed in [14].…”