scholarly journals Model-Based Stochastic Adaptive Air-Fuel Ratio Control of Direct Injection Biogas-Fuelled Engines

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jun Yang ◽  
Yanxiao Li ◽  
Jian Wang ◽  
Fangyuan Li
Keyword(s):  
Numerical Simulation ◽  
Dynamic Model ◽  
Methane Concentration ◽  
Closed Loop ◽  
Direct Injection ◽  
Mean Square ◽  
Closed Loop System ◽  
Fuel Ratio ◽  
Adaptive Law ◽  
Residual Gas

The problem of stochastic adaptive air-fuel ratio control by the dynamic model of biogas-fuelled engines is investigated in this paper. An adaptive law is employed to estimate the theoretical air-fuel ratio, which is undetermined due to the uncertainty of the methane concentration in the biogas. A stochastic adaptive air-fuel ratio controller in consideration of the stochasticity of the residual gas is designed based on the adaptive law, and the closed-loop system is proven to be mean-square stable. The proposed stochastic adaptive air-fuel ratio controller is validated through a numerical simulation when the theoretical air-fuel ratio is unknown constants and jump signals.

scholarly journals Damage Detection and Vibration Control of a Delaminated Smart Composite Plate

2000 ◽  
Vol 9 (1) ◽  
pp. 096369350000900 ◽  
Author(s):  
Aditi Chattopadhyay ◽  
Changho Nam ◽  
Youdan Kim
Keyword(s):  
Composite Plate ◽  
Closed Loop ◽  
Order Theory ◽  
Pole Placement ◽  
Transverse Shear Deformation ◽  
Mean Square ◽  
Smart Composite ◽  
Closed Loop System ◽  
Higher Order Theory ◽  
Placement Technique

In this paper, the effects of delamination on the dynamic characteristics of a composite plate are investigated. The refined higher order theory is used to model the smart composite plate in the presence of delaminations. The theory accurately captures the transverse shear deformation through the thickness, which is important in anisotropic composites, particularly in the presence of discrete actuators and sensors and delaminations. Next, the detection of delamination is investigated using the Root Mean Square (RMS) values of the response of the composite plate subject to disturbances. An active control system is designed to minimise the effect of delamination. The pole placement technique is applied to design the closed loop system by utilising piezoelectric actuators. Numerical results show that the RMS information can be used to estimate the location of the delamination. The controller designed makes the delaminated plate behave like a healthy plate model. The controller also reduces the magnitudes of RMS responses due to disturbance.

A New Controller of Stochastic Delay Systems

2011 ◽  
Vol 63-64 ◽  
pp. 974-977
Author(s):  
Yun Chen ◽  
Qing Qing Li
Keyword(s):  
Time Delay ◽  
Closed Loop ◽  
Stochastic Systems ◽  
Delay Systems ◽  
Mean Square ◽  
Closed Loop System ◽  
Stochastic Delay ◽  
Numerical Example ◽  
Mean Square Stability ◽  
Delay Dependent

By introducing an additional vector, a new delay-dependent controller is designed for stochastic systems with time delay in this paper. The presented controller is formulated by means of LMI, and it guarantees robust asymptotical mean-square stability of the resulting closed-loop system. Our result shows advantage over some existing ones, which is demonstrated by a numerical example.

scholarly journals StochasticH∞Control for Discrete-Time Singular Systems with State and Disturbance Dependent Noise

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Yong Zhao ◽  
Xiushan Jiang ◽  
Weihai Zhang
Keyword(s):  
Discrete Time ◽  
State Feedback ◽  
Closed Loop ◽  
Singular Systems ◽  
State Feedback Control ◽  
Linear Matrix ◽  
Mean Square ◽  
Matrix Inequalities ◽  
Closed Loop System ◽  
Theoretical Results

This paper is concerned with the stochasticH∞state feedback control problem for a class of discrete-time singular systems with state and disturbance dependent noise. Two stochastic bounded real lemmas (SBRLs) are proposed via strict linear matrix inequalities (LMIs). Based on the obtained SBRLs, a state feedbackH∞controller is presented, which not only guarantees the resulting closed-loop system to be mean square admissible but also satisfies a prescribedH∞performance level. A numerical example is finally given to illustrate the effectiveness of the proposed theoretical results.

Adaptive boundary control and vibration suppression of a flexible satellite system with input saturation

2018 ◽  
Vol 41 (9) ◽  
pp. 2666-2677
Author(s):  
Yun Fu ◽  
Yu Liu ◽  
Daoping Huang
Keyword(s):  
Boundary Control ◽  
Closed Loop ◽  
Vibration Suppression ◽  
Input Saturation ◽  
Satellite System ◽  
Closed Loop System ◽  
Adaptive Law ◽  
Control Scheme ◽  
Boundary Disturbance ◽  
Adaptive Boundary Control

In this paper, the vibration suppression problem of a flexible satellite system is addressed. The dynamic model of the flexible satellite system is expressed by a set of non-homogeneous partial differential equations (PDEs). By using the theory of systems with uniform ultimate bounded (UUB) solutions and adaptive techniques, adaptive boundary control is presented to suppress the vibration of the flexible satellite with parametric uncertainties. A disturbance adaptive law is constructed to compensate for the effect of the boundary disturbance, and an auxiliary system is considered to mitigate the effect of input saturation. The well-posedness of the closed-loop system is discussed, and UUB stability can be ensured through a rigorous Lyapunov-like analysis. Numerical simulation results show the effectiveness of the proposed control scheme.

Design and Simulation of Robust and Adaptive Controls for a Nonlinear String System1

2004 ◽  
Vol 126 (1) ◽  
pp. 54-62
Author(s):  
Weiwei Jin ◽  
Zhihua Qu ◽  
Kuo-Chi Lin
Keyword(s):  
Numerical Simulation ◽  
Vibration Control ◽  
Boundary Control ◽  
Closed Loop ◽  
Direct Method ◽  
Closed Loop System ◽  
Lyapunov Direct Method ◽  
Adaptive Controls ◽  
Control Designs ◽  
Nonlinear String

In this paper, vibration control of a nonlinear string system is considered. The system consists of a nonlinear string, two boundary supporting mechanisms, and a moving transporter at the base. To suppress the vibration, boundary control designs are carried out. A new robust and adaptive boundary controller is designed using the Lyapunov direct method. The proposed control is implemented at the two ends supporting the string to compensate for vibration induced by the base motion. It is shown that the adaptive/robust boundary control can asymptotically stabilize the nonlinear string. Numerical simulation of the closed loop system demonstrates the effectiveness of the proposed control.

Design and Simulation of Robust and Adaptive Controls for a Nonlinear String System

2000 ◽  
Author(s):  
Weiwei Jin ◽  
Zhihua Qu ◽  
Kurt Lin
Keyword(s):  
Numerical Simulation ◽  
Vibration Control ◽  
Boundary Control ◽  
Closed Loop ◽  
Direct Method ◽  
Closed Loop System ◽  
Lyapunov Direct Method ◽  
Adaptive Controls ◽  
Control Designs ◽  
Nonlinear String

Abstract In this paper, vibration control of a nonlinear string system is considered. The system consists of a nonlinear string, two boundary supporting mechanisms, and a moving transporter at the base. To suppress the vibration, boundary control designs are carried out. A new robust and adaptive boundary controller is designed using the Lyapunov direct method. The proposed control is implemented at the two ends supporting the string to compensate for vibration induced by the base motion. It is shown that the adaptive/robust boundary control can asymptotically stabilize the nonlinear string. Numerical simulation of the closed loop system demonstrates the effectiveness of the proposed control.

scholarly journals Real-Time Implementation of EEG Oscillatory Phase-Informed Visual Stimulation Using a Least Mean Square-Based AR Model

2021 ◽  
Vol 11 (1) ◽  
pp. 38
Author(s):  
Aqsa Shakeel ◽  
Takayuki Onojima ◽  
Toshihisa Tanaka ◽  
Keiichi Kitajo
Keyword(s):  
Real Time ◽  
Closed Loop ◽  
Loop System ◽  
Ar Model ◽  
Brain State ◽  
Mean Square ◽  
Least Mean Square ◽  
Closed Loop System ◽  
Alpha Oscillations ◽  
State Dependent

It is a technically challenging problem to assess the instantaneous brain state using electroencephalography (EEG) in a real-time closed-loop setup because the prediction of future signals is required to define the current state, such as the instantaneous phase and amplitude. To accomplish this in real-time, a conventional Yule–Walker (YW)-based autoregressive (AR) model has been used. However, the brain state-dependent real-time implementation of a closed-loop system employing an adaptive method has not yet been explored. Our primary purpose was to investigate whether time-series forward prediction using an adaptive least mean square (LMS)-based AR model would be implementable in a real-time closed-loop system or not. EEG state-dependent triggers synchronized with the EEG peaks and troughs of alpha oscillations in both an open-eyes resting state and a visual task. For the resting and visual conditions, statistical results showed that the proposed method succeeded in giving triggers at a specific phase of EEG oscillations for all participants. These individual results showed that the LMS-based AR model was successfully implemented in a real-time closed-loop system targeting specific phases of alpha oscillations and can be used as an adaptive alternative to the conventional and machine-learning approaches with a low computational load.

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