Polynomial Observer-Based Controller Synthesis and Fault-Tolerant Control for Tracking Optimal Power of Wind Energy Conversion Systems

In this study, the robust H ∞ fuzzy observer-based fault-tolerant tracking control strategy is proposed for the stochastic polynomial fuzzy system (SPFS) under the effect of external disturbance, measurement noise, system/sensor fault signals and continuous/discontinuous internal random fluctuations. At first, the smoothed models of fault signals are constructed to describe their dynamic behavior. Then, by integrating the SPFS with the smoothed models of fault signals as one augmented system, the state/fault signal estimation problem can be transformed to a state estimation problem of augmented system by the proposed polynomial fuzzy observer. With the utilization of estimated state/fault signals and reference trajectory, a fuzzy polynomial fault-tolerant tracking controller can be implemented. To attenuate the effect of undesired external disturbance and measurement noise on the state/fault signal estimation and tracking control performance, the robust H ∞ fuzzy observer-based fault-tolerant tracking control strategy is proposed in this study. By utilizing the homogeneous Lyapunov function and Lipschiz condition, the Itô-Lévy formula is reformulated to relax the compensation terms of stochastic processes during the design. Then, the design conditions are derived in terms of interpolation function-dependent matrix inequality and consequently transformed to a two-step sum of square (SOS) condition design problem for the robust H ∞ fuzzy observer-based fault-tolerant tracking control strategy. A simulation example of double lane maneuvering task for autonomous ground vehicle (AGV) is provided to illustrate the effectiveness of proposed method. Index terms: Observer-based tracking control, polynomial fuzzy system, stochastic control, fault-tolerant control, sum of square (SOS).

Section: ∂P (X)mentioning

confidence: 99%

Robust H_∞ Fuzzy Observer-Based Fault-Tolerant Tracking Control for Nonlinear Stochastic System: A Sum of Square Approach

Lee

Chen

2022

“…, = " + " m n (13) in which ∈ ℝ 6×6 and ∈ ℝ ,×, denote the positivedefinite weigh-matrices. The matrices and R are typically selected as the following diagonal matrices:…”

Section: Linear Quadratic Optimal Control Designmentioning

confidence: 99%

“…Moreover, a nonlinear observer was designed for WECS to estimate the rotor speed, position and the turbine torque in paper [12] where the frequency of the grid was time-varying and unknown. The polynomial observer combining with fault tolerant control was studied for the WECS to eliminate the influence of faults as well as tracking the maximum power point of WECS [13]. The sliding mode observer based nonlinear controller has been developed in paper [14] to estimate the wind speed, aerodynamic torque, and rotor speed of WECS.…”

Section: Introductionmentioning

confidence: 99%

Robust MPPT Observer-Based Control System for Wind Energy Conversion System With Uncertainties and Disturbance

Ngo

et al. 2021

Self Cite

The problem of tracking the maximum power point for the wind energy conversion system (WECS) is taken into consideration in this paper. The WECSs in this article is simultaneously affected by the uncertainties and the arbitrary disturbance that cause the WECSs to be much more challenging to control. A new method to synthesize a polynomial disturbance observer for estimating the aerodynamic torque, wind speed, and electromagnetic torque without using sensors is proposed in this paper. Unlike the previous methods, in this work, both the uncertainties and the disturbance are estimated, then estimations of the uncertainties and disturbance are transmitted to the Linear Quadratic Regular (LQR) controller for eliminating the influences of the uncertainties and disturbance; and tracking the optimal power point of WECS. It should be noted that the uncertainties in this work are time-varying and both uncertainties and disturbance do not need to satisfy the bounded constraints. The wind speed and aerodynamic torque are arbitrary and unnecessary to fulfil the low-varying constraint or r th time derivative bound. On the basis of Lyapunov methodology and sum-of-square technique (SOS), the main theorems are derived to design the polynomial disturbance observer. Finally, the simulation results are provided to demonstrate the effectiveness and merit of the proposed method.

“…The objective of the UIO is to estimate the value of the system states such that the estimation errors are decoupled from the unknown inputs acting on the system. The UIO is proposed for the considered system in the following form [26], [27]:…”

Section: Design Of the Fault Detection And Isolation A Design Of The Robust Unknown Input Observermentioning

confidence: 99%

“…Many aspects of the active FTC have been covered in the overview studies [20]- [23]. For designing the FDI, fullstate observers [24], [25], unknown input observers [26], [27], time-delay estimation [28], and numerous approaches have been proposed. The main difficulty of designing the FDI remains at decoupling the fault from other unknown factors, such as disturbances, perturbed parameters, and time delay.…”

Section: Introductionmentioning

confidence: 99%

Design of Robust Fault-Tolerant Control for Target Tracking System With Input Delay and Sensor Fault

Huynh

Kim

2021

This paper presents a robust fault-tolerant control scheme that provides reliable tracking and effective disturbance rejection for a low-cost tracking system. As the controlled apparatus, a 2-axis gimbaled mechanism is involved in a networked control system, and an unreliable sensor brings sensor drift into the system. Besides, external disturbances heavily affect the system in practical applications. Representation of the faulty gimbal system with its constraints and disturbances is firstly introduced. Then, the designed fault-tolerant controller consists of two components: (1) an unknown input observer estimates simultaneously information on the fault and effect of disturbances and networked delay, and (2) a robust control law, using the observer estimations, is based on the combination of the super-twisting algorithm, backstepping procedure, and integral sliding mode control technique. Subsequently, simulations and experiments are conducted, in which the performance of the proposed control system is compared to those from the previous studies. The results show the superiority and reliability of the proposed control system.INDEX TERMS Fault tolerant control, target tracking system, time-varying delay, unknown input observer, sensor drift, integral sliding mode control.