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This paper mainly concerns the issue of asynchronously switched control for a class of continuous-time switched linear systems with persistent dwell time (PDT). Asynchronous switching implies that when a subsystem switches the matched controller remains active for a finite period of time, such that the Lyapunov-like function increases. A semi-time-dependent (STD) multiple Lyapunov-like function with...
This paper examines the tracking property of nonlinear delayed multi-agent systems with impulsive effects. The strengths and locations of the stabilizing impulses, as well as the number of the controlled nodes are all assumed to be time-varying. Some sufficient criteria are established such that the considered system can exponentially track the dynamical reference state based on the given impulsive...
Wireless bilateral control based haptic teleoperation is a potential and challenging technique that extends human beings' sensing to a remote environment. However, communication delay in a bilateral control system directly influences the performance and even produces instability. This paper presents a stable and high performance bilateral control with a switching algorithm. This proposal uses the...
In this paper, we study the stability of fractional-order systems with distributed delays under Riemann-Liouville derivatives. First, the sufficient condition for stability of fractional-order system with distributed delays is presented by applying continuous frequency distributed equivalent model with indirect Lyapunov approach and combining Lyapunov-Krasovskii functionals with Jensen inequality...
Pattern recognition is a widespread application of the Wavelet Transform (WT). Sometimes, in real-time implementations a delay as low as possible is desired in the pattern detection process. This is especially important in applications such as breath or electrocardiogram (ECG) monitoring for life-support. Nevertheless, any real-time WT system which is actually implemented can present different sources...
This paper presents a comparison between two state estimation methods for processes with asynchronous and delayed measurements in order to verify which of these techniques is better in terms of dynamic behavior and possibilities of implementation in a real time processor. The methodologies are analyzed through simulations that allow a comparison in a visual form, through error index and with the time...
The objective of this work is to detect delay times between two ultrasonic signals, one of them considered as a reference and the other signal as the signal to be evaluated, using the wavelet transform, to indirectly estimate temperature changes. In this work the evaluation of 3 types of wavelets (Morlet, Mexican Hat and Daubechies 5) was made to detect the delay time in echo ultrasonic signals which...
Delay Tolerant Networks (DTNs) are sparse mobile ad-hoc networks in which there is typically no complete path between the source and destination. Although many routing algorithms for DTNs have been proposed, prior works generally focus on utilizing the delivery probability of network nodes and the social network structure for data forwarding. In this work, we investigate the use of the inter-contact...
Time Difference Of Arrival (TDOA) method is very often used inside electronic intelligence systems. TDOA method requires the high signal to noise ratio at the output of the intermediate frequency amplifier for target localization, usually around 12 dB or more. At low signal-to-noise ratio TDOA is inaccurate and especially in case of the active jamming it is nearly impossible. The multilateral TDOA...
With the omnipresence of the Internet of Things and poorly secured devices with it in combination with high bandwidth networks, Distributed Denial of Service (DDoS) attacks have become one of the biggest threats for network security. With high bandwidth attacks flooding network infrastructure, the pressure to secure the attack targets shifts more and more to the network operators. Often without direct...
In this work, we address the problem of reducing the vibrations in the case of a thin flexible beam, with an Euler-Bernoulli configuration thanks to a new type of feedback controller based on a delayed proportional action. The flexible structure is equipped with two piezoelectric patches: one of them works as a sensor and the other as an actuator. Each one of them is bonded on one side of the beam...
Vienna rectifier is one of the most popular topologies for three-phase PFC converter. Many control schemes were presented for Vienna rectifiers with unity power factor. Because of the small phase shift θ caused by the inductor or current detection delay, a zero-crossing detection error occurs, resulting in zero-crossing current spikes. This paper presents two SVPWM methods for three phase Vienna rectifiers...
This paper examines the accuracy of the zero-order hold (ZOH) model of the digital pulsewidth modulator (DPWM). The influence of the computational delay on the precision of this equivalent DPWM model is discussed in detail. A compensation method is proposed to compensate the deviation of this DPWM model for accurately calculating the stability region with different computational delay and duty-cycle...
This paper discusses the harmonics compensation of the constant dc-capacitor voltage-control (CDCVC)-based strategy of smart charger (SC) for electric vehicles (EVs) in single-phase three-wire distribution feeders (SPTWDFs) under the distorted source voltage and load currents conditions. The basic principle of the CDCVC-based harmonics compensation strategy under the distorted source voltage and load...
The main theme of this paper is to propose a self-commissioning technique for high bandwidth servo drives. The presented self-commissioning technique include auto-identification of servo motor parameters and on-line calculation of controller gains of servo drives. The electrical parameters required for current controller, including stator resistance and inductance are identified under standstill....
The high number of cells employed in a Modular Multilevel Converter represents a challenge for the control hardware. Some authors have proposed the use of digital communications to simplify the assemblage and maintenance in such converters, but the latency they add has undesirable consequences for the closed-loop performance. In this paper, we propose a model-based compensation of the latency that...
LCL-type grid-connected inverter is largely utilized in renewable generation system due to high harmonic suppression. In order to tackle the resonance issue induced by LCL-type filters, grid-side current feedback active damping method (GCFADM) without extra sensors has been extensively investigated. However, the damping characteristic under GCFADM has not been fully evaluated. In this paper, an improved...
This paper proposes a Zero-Voltage Ride-Through (ZVRT) method and an LCL filter optimization design method to meet the Fault Ride Through (FRT) requirements for a singlephase grid-tied inverter with a minimized LCL filter. The inverter output current overshoots at a voltage sag when the small LCL filter is used. As a proposed method in this paper, the inverter output current overshoot is suppressed...
In this study, a system has been developed to provide meaning and classification of e-mails according to their contents. The aim of the work is to develop an intelligent inbox to assist in awareness of information security. In the designed system, a client is developed that can connect to the server and receive e-mails. A two-step analysis is performed on the received e-mails. For both stage analysis,...
Increasing use of online backup services, as well as the popularity of user-generated content, has increased the demand for bandwidth. However, traffic generated by these applications can impact on the responsiveness of delay-sensitive applications if they receive a 'fair-share' of the available bandwidth. Less-than-Best-Effort TCP congestion control mechanisms aim to allow lower-priority applications...
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