Robust H∞ State Feedback Control of NCSs with Poisson Noise and Successive Packet Dropouts

Faiz Rasool,Sing Kiong Nguang 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.1

This paper examines various constraints of networked control systems (NCSs) such as network- induced random delays, successive packet dropouts and Poisson noise. Time delays are represented as modes of Markov chain and successive packet dropouts are modeled using Poisson probability distribution. For each delay-mode, a separate Poisson distribution is used with the help of an indicator function. Poisson noise is incorporated in the design to cater sudden network link failures and power shutdowns. After modeling these constraints, a stability criterion is proposed by using Lyapunov- Krasovskii functional. On the basis of the stability criteria, sufficient conditions for the existence of a robust H∞ state feedback controller are given in terms of bilinear matrix inequalities (BMIs). Later, BMIs are converted into quasi-convex linear matrix inequalities (LMIs) and are solved by using a cone complementarity linearizing algorithm. The effectiveness of the proposed scheme is elaborated with the help of two simulation examples. Moreover, the effects of successive packet dropouts and Poisson noise on H∞ performance are analyzed.

Dynamic Output Feedback Control for Uncertain Networked Control Systems with Random Network-induced Delays

Dan Huang,Sing Kiong Nguang 제어·로봇·시스템학회 2009 International Journal of Control, Automation, and Vol.7 No.5

This paper investigates the stabilization problem for a class of uncertain networked control systems (NCSs) with random communication network-induced delays. A dynamic output feedback controller is designed for the uncertain NCSs in the presence of network effects, i.e., network-induced delays and packet dropouts in both the sensor-controller and controller-actuator channels. Based on the Lyapunov-Razumikhin method, the existence of such controller is given in terms of the solvability of bilinear matrix inequalities. An iterative algorithm is proposed to change this non-convex problem into quasi-convex optimization problems, which can be solved effectively by available mathematical tools. The effectiveness of the proposed design methodology is verified by a numerical example.

Design of Capacitive Power Transfer Using a Class-E Resonant Inverter

Yusmarnita Yusop,Shakir Saat,Sing Kiong Nguang,Huzaimah Husin,Zamre Ghani 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

This paper presents a capacitive power transfer (CPT) system using a Class-E resonant inverter. A Class-E resonant inverter is chosen because of its ability to perform DC-to-AC inversion efficiently while significantly reducing switching losses. The proposed CPT system consists of an efficient Class-E resonant inverter and capacitive coupling formed by two flat rectangular transmitter and receiver plates. To understand CPT behavior, we study the effects of various coupling distances on output power performance. The proposed design is verified through lab experiments with a nominal operating frequency of 1 ㎒ and 0.25 ㎜ coupling gap. An efficiency of 96.3% is achieved. A simple frequency tracking unit is also proposed to tune the operating frequency in response to changes in the coupling gap. With this resonant frequency tracking unit, the efficiency of the proposed CPT system can be maintained within 96.3%–91% for the coupling gap range of 0.25–2 ㎜.

Finite-time Control for Discrete-time Markovian Jump Systems with Deterministic Switching and Time-delay

Jiwei Wen,Li Peng,Sing Kiong Nguang 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.3

In this paper, the finite-time control problem is investigated for a class of discrete-time Markovian jump systems (MJLSs) with deterministic switching and time-delay. The considered systems are subject to a piecewise-constant transition probability (TP) matrix, which leads to both the deterministic switches and stochastic jumps. First, the stochastic finite-time boundedness (SFTB) and l2 gain analysis for the systems are studied by employing the average dwell time (ADT) approach. Note that a finite-time weighted l2 gain is obtained to measure the disturbance attenuation level. Then, the mode-dependent and variation-dependent controller is designed such that the resulting closed-loop systems are stochastically finite-time bounded and have a guaranteed disturbance attenuation level. Finally, a numerical example is given to verify the potential of the developed results.

Mean Square Consensus of Multi-agent systems with multiplicative noises and time delays under directed fixed topologies

Dan Huang,Lei Song,Sing Kiong Nguang,Shan Fu 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.1

This paper investigates the mean square consensus problem of multi-agent systems impacted by thecombined uncertainty of multiplicative noises and time delays. Considering general network under directed fixedtopologies, we propose consensus protocol that take into account both the multiplicative noises and time delays. Using tools from stochastic differential delay equation (SDDE), martingale theory and stochastic inequality, weestablish sufficient conditions and obtain the explicit consensus gain and delay upper bounds under which theproposed protocol leads to mean square consensus. In addition, we compare the impact of multiplicative andadditive noise and reach the conclusion that multiplicative noises have the property of stabilizing effect. Simulationsdemonstrate the theoretical results.

Design of Capacitive Power Transfer Using a Class-E Resonant Inverter

Yusop, Yusmarnita,Saat, Shakir,Nguang, Sing Kiong,Husin, Huzaimah,Ghani, Zamre The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

This paper presents a capacitive power transfer (CPT) system using a Class-E resonant inverter. A Class-E resonant inverter is chosen because of its ability to perform DC-to-AC inversion efficiently while significantly reducing switching losses. The proposed CPT system consists of an efficient Class-E resonant inverter and capacitive coupling formed by two flat rectangular transmitter and receiver plates. To understand CPT behavior, we study the effects of various coupling distances on output power performance. The proposed design is verified through lab experiments with a nominal operating frequency of 1 MHz and 0.25 mm coupling gap. An efficiency of 96.3% is achieved. A simple frequency tracking unit is also proposed to tune the operating frequency in response to changes in the coupling gap. With this resonant frequency tracking unit, the efficiency of the proposed CPT system can be maintained within 96.3%-91% for the coupling gap range of 0.25-2 mm.

Secondary Side Output Voltage Stabilization of an IPT System by Tuning/Detuning through a Serial Tuned DC Voltage-controlled Variable Capacitor

Jianlong Tian,Aiguo Patrick Hu,Sing Kiong Nguang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

This paper proposes a method to stabilize the output voltage of the secondary side of an Inductive Power Transfer (IPT) system through tuning/detuning via a serial tuned DC Voltage-controlled Variable Capacitor (DVVC). The equivalent capacitance of the DVVC changes with the conduction period of a diode in the DVVC controlled by DC voltage. The output voltage of an IPT system can be made constant when this DVVC is used as a variable resonant capacitor combined with a PI controller generating DC control voltage according to the fluctuations of the output voltage. Since a passive diode instead of an active switch is used in the DVVC, there are no active switch driving problems such as a separate voltage source or gate drivers, which makes the DVVC especially advantageous when used at the secondary side of an IPT system. Moreover, since the equivalent capacitance of the DVVC can be controlled smoothly with a DC voltage and the passive diode generates less EMI than active switches, the DVVC has the potential to be used at much higher frequencies than traditional switch mode capacitors.

Secondary Side Output Voltage Stabilization of an IPT System by Tuning/Detuning through a Serial Tuned DC Voltage-controlled Variable Capacitor

Tian, Jianlong,Hu, Aiguo Patrick,Nguang, Sing Kiong The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

This paper proposes a method to stabilize the output voltage of the secondary side of an Inductive Power Transfer (IPT) system through tuning/detuning via a serial tuned DC Voltage-controlled Variable Capacitor (DVVC). The equivalent capacitance of the DVVC changes with the conduction period of a diode in the DVVC controlled by DC voltage. The output voltage of an IPT system can be made constant when this DVVC is used as a variable resonant capacitor combined with a PI controller generating DC control voltage according to the fluctuations of the output voltage. Since a passive diode instead of an active switch is used in the DVVC, there are no active switch driving problems such as a separate voltage source or gate drivers, which makes the DVVC especially advantageous when used at the secondary side of an IPT system. Moreover, since the equivalent capacitance of the DVVC can be controlled smoothly with a DC voltage and the passive diode generates less EMI than active switches, the DVVC has the potential to be used at much higher frequencies than traditional switch mode capacitors.