Quality monitoring of a closed-loop system with parametric uncertainties and external disturbances: a fault detection and isolation approach

2010 ◽  
Vol 55 (1-4) ◽  
pp. 293-306 ◽  
Author(s):  
M. A. Rahim ◽  
Haris M. Khalid ◽  
Muhammad Akram ◽  
Amar Khoukhi ◽  
L. Cheded ◽  
...  
Keyword(s):  
Fault Detection ◽  
Closed Loop ◽  
Loop System ◽  
Fault Detection And Isolation ◽  
Quality Monitoring ◽  
Parametric Uncertainties ◽  
Closed Loop System ◽  
External Disturbances

Robust Fault Tolerant Control for Spacecraft Attitude Stabilization Under Actuator Faults and Bounded Disturbance

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Bing Xiao ◽  
Qinglei Hu ◽  
Michael I. Friswell
Keyword(s):  
Closed Loop ◽  
Fault Tolerant ◽  
Fault Detection And Isolation ◽  
Spacecraft Attitude ◽  
Actuator Faults ◽  
Closed Loop System ◽  
External Disturbances ◽  
Attitude Stabilization ◽  
Bounded Disturbance ◽  
Loss Of Actuator Effectiveness

This paper investigates the design of spacecraft attitude stabilization controllers that are robust against actuator faults and external disturbances. A nominal controller is developed initially, using the adaptive backstepping technique, to stabilize asymptotically the spacecraft attitude when the actuators are fault-free. Additive faults and the partial loss of actuator effectiveness are considered simultaneously and an auxiliary controller is designed in addition to the nominal controller to compensate for the system faults. This auxiliary controller does not use any fault detection and isolation mechanism to detect, separate, and identify the actuator faults online. The attitude orientation and angular velocity of the closed-loop system asymptotically converge to zero despite actuator faults providing the nominal attitude system is asymptotically stable. Numerical simulation results are presented that demonstrate the closed-loop performance benefits of the proposed control law and illustrate its robustness to external disturbances and actuator faults.

scholarly journals Adaptive Robust Quadratic Stabilization Tracking Control for Robotic System with Uncertainties and External Disturbances

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jinzhu Peng ◽  
Yan Liu
Keyword(s):  
Closed Loop ◽  
Robot Manipulator ◽  
Variable Structure ◽  
Robotic System ◽  
Loop System ◽  
Closed Loop System ◽  
Hybrid Scheme ◽  
External Disturbances ◽  
Control Approach ◽  
Quadratic Stabilization

An adaptive robust quadratic stabilization tracking controller with hybrid scheme is proposed for robotic system with uncertainties and external disturbances. The hybrid scheme combines computed torque controller (CTC) with an adaptive robust compensator, in which variable structure control (VSC) andH∞optimal control approaches are adopted. The uncertain robot manipulator is mainly controlled by CTC, the VSC is used to eliminate the effect of the uncertainties and ensure global stability, andH∞approach is designed to achieve a certain tracking performance of closed-loop system. A quadratic stability approach, which allows separate treatment of parametric uncertainties, is used to reduce the conservatism of the conventional robust control approach. It can be also guaranteed that all signals in closed-loop system are bounded. The validity of the proposed control scheme is shown by computer simulation of a two-link robotic manipulator.

Immersion- and invariance-based adaptive missile control using filtered signals

2012 ◽  
Vol 226 (6) ◽  
pp. 646-663 ◽  
Author(s):  
K W Lee ◽  
S N Singh
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Angle Of Attack ◽  
Loop System ◽  
Certainty Equivalent ◽  
Analytical Relation ◽  
Parametric Uncertainties ◽  
State Variables ◽  
Closed Loop System ◽  
Immersion And Invariance

The article presents a new non-certainty-equivalent adaptive (NCEA) longitudinal autopilot for the control of a missile based on the immersion and invariance theory. The interest here is to control the angle of attack of the missile in the presence of large parametric uncertainties. For the derivation of the control law, a backstepping design procedure is used. At each step of the design, certain filtered signals are generated for the synthesis of a stabilizing control signal and a parameter estimator. Using Lyapunov stability analysis, it is shown that in the closed-loop system, trajectory control of the angle of attack is accomplished, and the trajectories of the system are attracted to certain manifold in the space of state variables and parameter errors. For stability in the closed-loop system, an explicit analytical relation involving the controller gains is obtained. It may be pointed out that recently an adaptive autopilot based on the immersion and inversion theory has been designed, but it has stringent requirements because for its synthesis, the derivatives of the Mach number and angle of attack must be known, and a large number of parameters must be updated. The derived control system of this article is synthesized using only the state variables, and its identifier is of lower order. A traditional certainty-equivalent adaptive autopilot is also presented for comparison. Simulation results are obtained which show that the designed NCEA control system can accomplish angle of attack control despite large parametric uncertainties; and it can give better tracking performance than the traditional controller.

Output Feedback Algorithm for Nonlinear Systems with Compensation of Bounded Disturbances and Measurement Noises

2019 ◽  
Vol 20 (1) ◽  
pp. 3-15 ◽  
Author(s):  
I. B. Furtat ◽  
P. A. Gushchin ◽  
A. A. Peregudin
Keyword(s):  
Output Feedback ◽  
Closed Loop ◽  
Sufficient Conditions ◽  
Loop System ◽  
Partial Recovery ◽  
Closed Loop System ◽  
External Disturbances ◽  
Control Schemes ◽  
Measurement Noises ◽  
Feedback Algorithm

The output feedback algorithm for dynamic plants with compensation of parametric uncertainty, external disturbances and measurement noises is synthesized. The plants are described by a nonlinear system of differential equations with vector input and output signals. Unlike most existing control schemes in this paper the dimensions of the measurement interference and the output signal are equal, the sources of the signals of disturbances and disturbances are different, parametric and external disturbances can be present in any equation of the plant model. For simultaneous compensation of disturbances and measurement noises it is proposed to consider two channels. On the first channel a part of the measurement noises will be estimated which will allow partial recovery the information about the plant noisy output. On the second channel the disturbances will be compensated. Thus, at least two independent measurement channels are required for simultaneous compensation of disturbances and measurement noises. Sufficient conditions for calculating the parameters of the algorithm in the form of solvability of the linear matrix inequality are obtained. It is shown that the equation of a closed-loop system obtained on the basis of the proposed algorithm depends on the disturbances and the smallest component of the measurement noise. However, if the smallest component cannot be identified a priory, the results of the transients depend on the component of the noise that will be selected in the synthesis of the control system. Thus, unlike most existing control schemes, where the equation of a closed-loop system depends on disturbance and noise, the resulting algorithm provides better transients, because they do not depend on the entire noise vector, but only on its smallest (one) component. The simulations for a third-order nonlinear plant and the synchronization of an electrical generator connected to the power grid are presented. Numerical examples illustrate the effectiveness of the proposed scheme and the robustness with respect to random components in the noises and disturbances.

Direct Adaptive CMAC PI Control for Uncertain Nonlinear Systems with Measurable Output Feedback

2013 ◽  
Vol 479-480 ◽  
pp. 612-616
Author(s):  
Chun Sheng Chen
Keyword(s):  
Nonlinear Systems ◽  
Closed Loop ◽  
Control Structure ◽  
Loop System ◽  
Pi Control ◽  
Uncertain Nonlinear Systems ◽  
Closed Loop System ◽  
External Disturbances ◽  
Lyapunov Stability Criterion ◽  
System Output

A stable direct adaptive CMAC PI controller for a class of uncertain nonlinear systems is investigated under the constrain that only the system output is available for measurement. First, a state observer is used to estimate unmeasured states of the systems. Then, the PI control structure is used for improving robustness in the closed-loop system and avoiding affection of uncertainties and external disturbances. The global asymptotic stability of the closed-loop system is guaranteed according to the Lyapunov stability criterion. To demonstrate the effectiveness of the proposed method, simulation results indicate that the proposed approach is capable of achieving a good trajectory following performance without the knowledge of plant parameters.

Controller Design and Stability Analysis of Output Pressure Regulation in Electrohydrostatic Actuators

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Masoumeh Esfandiari ◽  
Nariman Sepehri
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Loop System ◽  
Linear Matrix ◽  
Parametric Uncertainties ◽  
Closed Loop System ◽  
Output Pressure ◽  
Frequency Responses ◽  
Wide Range ◽  
The Stability

In this paper, a robust fixed-gain linear output pressure controller is designed for a double-rod electrohydrostatic actuator using quantitative feedback theory (QFT). First, the family of frequency responses of the system is identified by applying an advanced form of fast Fourier transform on the open-loop input–output experimental data. This approach results in realistic frequency responses of the system, which prevents the generation of unnecessary large QFT templates, and consequently contributes to the design of a low-order QFT controller. The designed controller provides desired transient responses, desired tracking bandwidth, robust stability, and disturbance rejection for the closed-loop system. Experimental results confirm the desired performance met by the QFT controller. Then, the nonlinear stability of the closed-loop system is analyzed considering the friction and leakage, and in the presence of parametric uncertainties. For this analysis, Takagi–Sugeno (T–S) fuzzy modeling and its stability theory are employed. The T–S fuzzy model is derived for the closed-loop system and the stability conditions are presented as linear matrix inequalities (LMIs). LMIs are found feasible and thus the stability of the closed-loop system is proven for a wide range of parametric uncertainties and in the presence of friction and leakages.

scholarly journals Stochastic Hybrid Estimator Based Fault Detection and Isolation for Wind Energy Conversion Systems with Unknown Fault Inputs

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2227 ◽  
Author(s):  
Yun-Tao Shi ◽  
Yuan Zhang ◽  
Xiang Xiang ◽  
Li Wang ◽  
Zhen-Wu Lei ◽  
...  
Keyword(s):  
Fault Detection ◽  
Wind Energy ◽  
Energy Conversion ◽  
Closed Loop ◽  
Stochastic Dynamics ◽  
Fault Detection And Isolation ◽  
Closed Loop System ◽  
Wind Energy Conversion ◽  
Discrete States ◽  
Hybrid Estimator

In recent years, the wind energy conversion system (WECS) has been becoming the vital system to acquire wind energy. However, the high failure rate of WECSs leads to expensive costs for the maintenance of WECSs. Therefore, how to detect and isolate the faults of WECSs with stochastic dynamics is the pressing issue in the literature. This paper proposes a novel comprehensive fault detection and isolation (FDI) method for WECSs. First, a stochastic model predictive control (SMPC) controller is studied to construct the closed-loop system of the WECS. This controller is based on the Markov-jump linear model, which could precisely establish the stochastic dynamics of the WECS. Meanwhile, the SMPC controller has satisfied control performance for the WECS. Second, based on the closed-loop system with SMPC, the stochastic hybrid estimator (SHE) is designed to estimate the continuous and discrete states of the WECS. Compared with the existing estimators for WECSs, the proposed estimator is more suitable for WECSs since it considers both the continuous and discrete states of WECSs. In addition, the proposed estimator is robust to the fault input. Finally, with the proposed estimator, the comprehensive FDI method is given to detect and isolate the actuators’ faults of the WECS. Both the system status and the actuators’ faults can be detected by the FDI method and it can effectively quantify the actuators’ fault by the fault residuals. The simulation results suggest that the SHE could effectively estimate the hybrid states of the WECS, and the proposed FDI method gives satisfied fault detection performance for the actuators of the WECS.

scholarly journals Robust Optimal Attitude Controller for MIMO Uncertain Hexarotor MAVs: Disturbance Observer-Based

2016 ◽  
Vol 2016 ◽  
pp. 1-24 ◽  
Author(s):  
Nurul Dayana Salim ◽  
Dafizal Derawi ◽  
Hairi Zamzuri ◽  
Kenzo Nonami ◽  
Mohd Azizi Abdul Rahman
Keyword(s):  
Nonlinear Dynamics ◽  
Attitude Control ◽  
Disturbance Observer ◽  
Closed Loop ◽  
Control Design ◽  
Loop System ◽  
Parametric Uncertainties ◽  
Time Varying ◽  
Closed Loop System ◽  
External Time

This paper proposes a robust optimal attitude control design for multiple-input, multiple-output (MIMO) uncertain hexarotor micro aerial vehicles (MAVs) in the presence of parametric uncertainties, external time-varying disturbances, nonlinear dynamics, and coupling. The parametric uncertainties, external time-varying disturbances, nonlinear dynamics, and coupling are treated as the total disturbance in the proposed design. The proposed controller is achieved in two simple steps. First, an optimal linear-quadratic regulator (LQR) controller is designed to guarantee that the nominal closed-loop system is asymptotically stable without considering the total disturbance. After that, a disturbance observer is integrated into the closed-loop system to estimate the total disturbance acting on the system. The total disturbance is compensated by a compensation input based on the estimated total disturbance. Robust properties analysis is given to prove that the state is ultimately bounded in specified boundaries. Simulation results illustrate the robustness of the disturbance observer-based optimal attitude control design for hovering and aggressive flight missions in the presence of the total disturbance.

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