Applied Mechanics and Materials Vols. 241-244

Abstract: In this paper a surface micromachined MEMS Piezoresistive pressure sensor was designed. A simulation programs were developed to predict the sensitivity and linearity behavior of the piezoresistive pressure sensor. Based on the small and large deflection theory the diaphragm performances were analyzed. Different diaphragm shape, pressure range, placement of resistors and the properties of the resistors were considered during the analysis. The output response of the pressure sensor was also found as a function of temperature and pressure. It was found that silicon germanium gave better sensitivity and less linearity error. The analysis showed that sensitivity and linearity are influenced by diaphragm thickness and length of the sensing resistor used in the diaphragm of the Piezoresistive pressure sensor. It was found that the sensitivity of 5.2mV/V can be achieved for silicon germanium

Abstract: In recent years, as the development of wireless sensor network, people do some deep researches on cluster-based protocol, most around the prolongation of the lifetime of WSN and decline of energy consumed by the sensors. This paper analyses of classical clustering routing protocol based on LEACH, aiming at the node energy foot presents energy improved clustering routing algorithm, the random cluster head selection algorithm of threshold to be changed, lowering the threshold, in the original threshold increases the node's remaining energy factor, reduces the communication load of cluster nodes, and simulation. The simulation results show that the LEACH-E improved algorithm, energy saving, reducing balance node energy consumption, effectively prolongs the network lifetime.

Abstract: Topology control has been well studied in wireless sensor networks. Power control technology as one way of topology control can be used to indirectly reduce the interference due to low degree sparse topologies produced by it. It has often been assumed that a sparse graph implicitly has low interference, but recent research shows that that is not necessarily true. In this paper, we discuss several typical methods to measure interference, and present a new interference model that aims to describe the interference of the entire network. We present LIST, a topology control algorithm that serves two purposes: it minimizes the interference in the network according to our metrics, and it keeps the spanner properties of the original graph. The paper is completed by simulations that compare different topologies with respect to different interference metrics. Some analyses of simulations results are given in the end.

Abstract: The localization of Underwater Sensor Networks(UWSNs) faces great challenges with the special underwater environment. In this page, the depth information is considered to use for localization. A novel localization scheme named U-iTPS is designed for UWSNs. Nodes do not rely on special hardware or time synchronization and depend on time difference of arrival (TDoA) signals measured locally to detect range differences from themselves to four anchors and then locate themselves in U-iTPS. U-iTPS is energy conservation because it does not rely on the node degree and the number of anchors, in which the node does not need communication each other and only listen to the beacon packets. After intensive experiment and theoretical analysis, U-iTPS show better performance such as low storage, computation and communication with other schemes, and also show good robustness in the underwater environment.

Abstract: Based on the Agilent N6841A RF sensor, we took in-depth analysis and research on the basic principles, and for secondary development from the perspective of monitoring, storing the IQ data of unknown signals. Proposed analysis of the unknown signal based on RF sensor is to prepare for carrier frequency measurement, modulation recognition in order to achieve automated radio monitoring.

Abstract: Recent advances in wireless sensor networks (WSNs) now witness the increased interest in the potential use in applications. Sensors are expected to be remotely deployed in large numbers and operate autonomously in unattended environments. In this paper, Ant-colony-based Geographic and Energy Balance Routing (AGEBR) was utilized to establish wireless sensor networks which had survival cycles. This Ant-colony-based routing can modify the geographic information based on the distribution characteristics of the ant colony algorithm, and finally achieve fast convergence and high efficiency. As a result, the sensor networks which did not have lasting energy supplement or only had limited energy complement could last a longer period without losing their sensing ability. Experimental results demonstrated that the proposed approach can keep balance of the network energy consumption, prolong the network lifetime, and enhance the successful sending rate without congestion.

Abstract: Digital fiber-optic gyroscope with linear scale factor, phase high accuracy, dynamic range, etc. This article proposed one kind of closed-loop digital fiber optic gyroscope system based on DSP, and designs the closed-loop fiber-optic gyro for signal detection and processing circuit, and the whole digital closed loop of fiber optic gyroscope light path part and circuit of the concrete analysis. With DSP as logic circuit, make the gyro operation speed and reliability have improved greatly.

Abstract: The electrical field finite element mathematical model of electrical capacitance and resistance dual-modality tomography sensor has been established. The dual-modality tomography sensors are installed on the different cross-section of the same pipeline with metal-wall. The electrical characteristic of dual-modality sensing fields was analysized. The simulation result of the provided theoretical model is the basis for dual-modality imaging algorithm and information fusion.

Abstract: In this paper, synchronization control method of Zagzag system is discussed both theoretically and numerically. Based on the Lyapunov stability theorem and the chaotic methods, synchronization control is given and illustrated with Zagzag system as example. Numerical simulations are presented to demonstrate the effectiveness of the proposed synchronization scheme.

Abstract: The electric power steering system (EPS) is a combination of mechanical and electrical control system. EPS’control strategy used commonly has two kinds: current PID control and fuzzy control .The current PID control based on the difference between target current and feedback current is a curren closed-loop control system and the fuzzy control is a mechanical closed-loop control system based on the difference between forces of the upper part and the lower part of the steering shaft . Taking the margin of the mechanical and electrical closed-loop control system, this paper, a torque feedback loop for the outer ring, a current feedback loop as the inner loop, designed a dual-loop control system, the output of the fuzzy control determined a target current, and then proceed to current PID control, fast-track the target torque. The simulation shows the dual closed-loop fuzzy PID control is superior to two commonly used control strategies so that electric power steering system has a better tracking ability and stability.