L1 adaptive controller for MIMO systems with unmatched uncertainties using modified piecewise constant adaptation law

2012 ◽  
Author(s):  
Zhiyuan Li ◽  
Naira Hovakimyan
Keyword(s):  
Mimo Systems ◽  
Adaptive Controller ◽  
Piecewise Constant ◽  
Unmatched Uncertainties ◽  
Adaptation Law

scholarly journals Neural Adaptive PID and Neural Indirect Adaptive Control Switch Controller for Nonlinear MIMO Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Sabrine Slama ◽  
Ayachi Errachdi ◽  
Mohamed Benrejeb
Keyword(s):  
Neural Network ◽  
Mimo Systems ◽  
Reference Signal ◽  
Adaptive Controller ◽  
Tracking Performance ◽  
Actual System ◽  
Neural Structure ◽  
The Neural Network ◽  
Adaptation Law ◽  
Adaptive Switch

This paper proposes an adaptive switch controller (ASC) design for the nonlinear multi-input multi-output system (MIMO). In fact, the proposed method is an online switch between the neural network adaptive PID (APID) controller and the neural network indirect adaptive controller (IAC). According to the design of the neural network IAC scheme, the adaptation law has been developed by the gradient descent (GD) method. However, the adaptive PID controller is built based on the neural network combining the PID control and explicit neural structure. The strategy of training consists of online tuning of the neural controller weights using the backpropagation algorithm to select the suitable combination of PID gains such that the error between the reference signal and the actual system output converges to zero. The stability and tracking performance of the neural network ASC, the neural network APID, and the neural network IAC are analyzed and evaluated by the Lyapunov function. Then, the controller results are compared between APID, IAC, and ASC, in this paper, applying to a nonlinear system. From simulations, the proposed adaptive switch controller has better effects both on response time and on tracking performance with smallest MSE.

L1 adaptive control design of a helicopter in vertical flight

2020 ◽  
Vol 234 (14) ◽  
pp. 2089-2099
Author(s):  
Song Tian ◽  
Jiang Wang ◽  
Defu Lin ◽  
Pei Pei
Keyword(s):  
Adaptive Control ◽  
Flight Control ◽  
Control Design ◽  
Adaptive Controller ◽  
Piecewise Constant ◽  
L1 Adaptive Control ◽  
Control Scheme ◽  
Practical Engineering ◽  
Adaptation Law ◽  
Adaptive Control Scheme

This article presents L1 adaptive control scheme for vertical flight control of helicopter. Linear controller is designed as baseline controller to provide preliminary improvement in performance and robustness. Considering the existence of uncertainties and disturbances, we propose L1 adaptive controller with modified piecewise constant adaptation law to augment the baseline controllers. Further, the proposed L1 adaptive controller can be implemented without any modification of the baseline controller. Benefit from this, the design of the entire control system is significantly simplified, and the designed controller is easy to apply to practical engineering. The simulation results indicate that the proposed controllers have good performance for helicopter vertical flight in the presence of uncertainties and disturbances.

scholarly journals Neural NetworkL1Adaptive Control of MIMO Systems with Nonlinear Uncertainty

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hong-tao Zhen ◽  
Xiao-hui Qi ◽  
Jie Li ◽  
Qing-min Tian
Keyword(s):  
Mimo Systems ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Adaptive Controller ◽  
Rbf Neural Networks ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Input Multiple Output ◽  
Low Pass ◽  
Nonlinear Uncertainties

An indirect adaptive controller is developed for a class of multiple-input multiple-output (MIMO) nonlinear systems with unknown uncertainties. This control system is comprised of anL1adaptive controller and an auxiliary neural network (NN) compensation controller. TheL1adaptive controller has guaranteed transient response in addition to stable tracking. In this architecture, a low-pass filter is adopted to guarantee fast adaptive rate without generating high-frequency oscillations in control signals. The auxiliary compensation controller is designed to approximate the unknown nonlinear functions by MIMO RBF neural networks to suppress the influence of uncertainties. NN weights are tuned on-line with no prior training and the project operator ensures the weights bounded. The global stability of the closed-system is derived based on the Lyapunov function. Numerical simulations of an MIMO system coupled with nonlinear uncertainties are used to illustrate the practical potential of our theoretical results.

scholarly journals L1 Adaptive for Aircraft Lateral Fault Tolerant Control with Actuator Failure

2019 ◽  
Vol 37 (5) ◽  
pp. 935-942
Author(s):  
Yan Zhou ◽  
Huiying Liu ◽  
Jing Li
Keyword(s):  
Control Method ◽  
Fault Tolerant ◽  
Adaptive Controller ◽  
Actuator Failure ◽  
Bounded Control ◽  
L1 Adaptive Control ◽  
Unmatched Uncertainties ◽  
Fault Mode ◽  
The Stability ◽  
Multiplicative Fault

When aircraft is laterally controlled, actuator failure may cause matched/unmatched uncertainties. In order to deal with the uncertainty, a fault-tolerant controller is designed by using L1 adaptive control method. An aircraft lateral model was established by considering faults and disturbances, the effects of the uncertainty and interference were counteracted by using L1 adaptive controller in order to ensure the rapid adaptation and robustness, and then the stability and transient performance of the closed-loop system were proven through Lyapunov method. In the case of multiplicative fault, additive fault and stuck fault, the uncertainties of model parameter were added to simulate simultaneously. Simulation results showed that the present control method in both single-fault mode and hybrid-failure mode could ensure the uniform bounded control signal and parameter estimation, effectively eliminates the effect of the faults and had the good fault tolerance and robustness.

scholarly journals Adaptive augmentation of the attitude control system for a multirotor unmanned aerial vehicle

2018 ◽  
Vol 234 (10) ◽  
pp. 1587-1596
Author(s):  
G Bressan ◽  
A Russo ◽  
D Invernizzi ◽  
M Giurato ◽  
S Panza ◽  
...  
Keyword(s):  
Control System ◽  
Unmanned Aerial Vehicle ◽  
Attitude Control ◽  
Adaptive Controller ◽  
Attitude Control System ◽  
Loop Dynamics ◽  
The Standard Model ◽  
Aerial Vehicle ◽  
Adaptation Law ◽  
Model Reference Adaptive

In this paper, the adaptive augmentation of the attitude control system for a multirotor unmanned aerial vehicle is considered. The proposed approach allows to combine a baseline controller with an adaptive one and to disable or enable the adaptive controller when needed, in order to take the advantages of both the controllers. To improve transient performance with respect to the standard model reference adaptive controller, an observed-based approach is exploited. The adaptation law is based on the error between the output of an observer of the nominal closed-loop dynamics and the actual output of the system with uncertainties. Experimental results obtained by testing the proposed approach on a quadrotor unmanned aerial vehicle are presented to compare the performance, in terms of disturbance rejection, with respect to the baseline controller and to a [Formula: see text] adaptive augmentation scheme.

scholarly journals Adaptive robust fault-tolerant control for linear MIMO systems with unmatched uncertainties

2016 ◽  
Vol 90 (10) ◽  
pp. 2253-2269 ◽  
Author(s):  
Kangkang Zhang ◽  
Bin Jiang ◽  
Xing-Gang Yan ◽  
Zehui Mao
Keyword(s):  
Fault Tolerant ◽  
Mimo Systems ◽  
Fault Tolerant Control ◽  
Unmatched Uncertainties

scholarly journals Adaptive Sliding Mode Control Vibrations of Structures

2021 ◽  
Author(s):  
Fali Leyla ◽  
Zizouni Khaled ◽  
Saidi Abdelkrim ◽  
Bousserhane Ismail Khalil ◽  
Djermane Mohamed
Keyword(s):  
Controller Design ◽  
Sliding Mode ◽  
Adaptive Controller ◽  
Structural Vibration ◽  
Adaptive Sliding Mode Control ◽  
Sliding Mode Controller ◽  
Active Devices ◽  
The Stability ◽  
Adaptation Law ◽  
Low Sensitivity

The sliding mode controller is one of the interesting classical nonlinear controllers in structural vibration control. From its apparition, in the middle of the twentieth century, this controller was a subject of several studies and investigations. This controller was widely used in the control of various semi-active or active devices in the civil engineering area. Nevertheless, the sliding mode controller offered a low sensitivity to the uncertainties or the system condition variations despite the presence of the Chattering defect. However, the adaptation law is one of the frequently used solutions to overcome this phenomenon offering the possibility to adapt the controller parameters according to the system variations and keeping the stability of the whole system assured. The chapter provides a sliding mode controller design reinforced by an adaptive law to control the desired state of an excited system. The performance of the adaptive controller is proved by numerical simulation results of a three-story excited structure.

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