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The quality of the communication links in VPLC (vehicular power line communication) suffer from an impedance mismatch resulting from fluctuating VPLN (Vehicular Power Line Network) access impedance, which renders the fixed impedance matching circuit inefficient. In this paper, we designed a T-shaped adaptive impedance matching system on the basis of the resonance- and absorption-based T-shaped network complex impedance matching approach. We identified the load-Q (quality factor) for different matching situations to facilitate designing T-shaped networks with broad bandwidths. The designed T-shaped adaptive impedance matching system adjusts the component values of the T-shaped network to implement adaptive impedance matching between the VPLC modem and VPLN. A set of simulations are conducted for 1 MHz-100 MHz, which demonstrates that the designed adaptive matching system with a simple circuit structure and control logic is capable of significantly improving signal power transfer.

Impedance mismatch that degrades signal power transfer and affects communication reliability is a major obstacle for power line communications (PLC). Impedance matching techniques can be designed to effectively compensate for the impedance mismatch between PLC modems and power line networks at a specific frequency or for a given frequency band. In this paper, we discuss the tradeoffs that need to be made when designing an effective impedance matching network. We also make a comprehensive review of previous state-of-the-art PLC impedance matching techniques and provide a useful classification of each technique. Finally, we discuss important issues (concerns) and provide suggestions for research directions deserving more attention. This review provides a useful guideline for researchers and manufacturers to quickly understand impedance matching principles and facilitate the design of an effective impedance matching coupler for PLC applications.

In power line communication (PLC), coupling transformers are usually required for coupling, band-pass filtering and impedance matching. However, coupling transformer design involves so many parameters that it is typically an imprecise and experimental procedure. In addition, the cost and size of transformers prevent them from being an economic and compact solution for PLC couplers. This paper first analyzes a simplified, distributed parameter model of the power line, which can be used to calculate power line impedance easily and accurately. Next, a low-cost, band-pass matching coupler with compact architecture is designed to replace the coupling transformer for direct current PLC (DC-PLC), which ensures impedance matching on the basis of an accurate power line impedance instead of using an average value. Finally, simulations as well as laboratory tests are conducted under 95–125[Formula: see text]kHz (CENELEC B-band), which confirm the new coupler’s excellent band-pass filtering and impedance matching performance.

In this paper, the finite-time tracking control problem for multiple nonholonomic mobile robots in the presence of external disturbances and uncertainties is investigated. First of all, the resulting tracking error system is derived. Secondly, continuous distributed cooperative finite-time tracking control laws are designed for each mobile robot, where the communication topology among the multiple mobile robots is assumed to be a directed graph. Rigorous proof shows that the group of mobile robots converge to the desired reference trajectory in finite time. Simulation example illustrates the effectiveness of our method.