Applied Mechanics and Materials Vols. 568-570

Abstract: A perimeter intrusion detection system (PIDS) based on sensor network is proposed and designed for safeguarding important area from illegal intrusion. The PIDS consists of a front-end detection sub-system, a control center sub-system, anassociated sub-system, a network transmission sub-system and a power supply sub-system. The front-end detection sub-system is a sensor network containing a large number of smart sensors, which are of different types and functions. The control center sub-system is an integrated control platform based on the special analysis software, which can accurately identify the type of intrusion, locate the intrusion target, and reduce false alarms caused by environmental interference. The other four sub-systems provide the associated video monitoring, acoustic or optical alarm, wired or wireless transmission and AC or DC power supply. The development of sensor network technology has been and will continue to promote the PIDS technology.

Abstract: The optical source is one of the key components for the optical pump magnetic field sensor, its spectral width, stability and emission intensity directly related to the sensitivity of the sensor. The CS Spectral Lamp drive signal source was produced by crystal oscillator and amplified by the power controllable RF power amplifier. For achieving the aim of luminous intensity controllable and more stability, the reference controllable analog PI negative feedback control measures were used in the drive circuit. Contrast experimental result show that: the emission intensity of CS spectrum lamp is more stable and less affected by temperature if using the drive circuit which discussed in this paper.

Abstract: EVT (electronic voltage transformer) is one of the key devices of the intelligent substation. This paper introduces the basic principles of EVT error tests. By analyzing the test environment of EVT with GIS structure, this paper establishes the high-voltage side equivalent circuit for the field EVT calibration methods and proposes to carry out field boost for the EVT with GIS structure, which could effectively improve the field calibration efficiency of EVT. Based on the research on the complex field environment of EVT, this paper puts forward the field test methods of EVT with AIS structure and the results show the effectiveness and correctness of this study.

Abstract: Technology of machine vision is used to measure the inside and outside diameter and concentricity of the optical fiber connector internal parts without contact. The image is got by million-pixel industrial camera. Then the image gets pretreatment, such as, grayscale transformation, binarization, smoothing, etc. Appropriate detection threshold is found by the image analysis. The edge of parts is found by the circular probe method. Inside and outside diameter and concentricity of parts are obtained by using the edge of the data through the least squares method. Experiment of 6.4 mm diameter parts, absolute error is less than one pixel. The largest error is less than 0.05 mm compared with the manual measurements and can meet the measurement requirements.

Abstract: With the development of measurement and control technology of range,it has proposed new requirements on storage ability. The paper introduces the significance of high-speed storage technology used in measurement and control technology of range.The paper also analyzes three application methods.The advantages of FLASH storage ways and the specific method are described in it.

Abstract: This paper is related to the design of an upper-limb motion recognition system based on a new-style MEMS sensor MPU-9150.In order to obtain more accurate deflection Angle, we describe the output of the 3-axis gyroscope and 3-axis accelerometer data with quaternion differential equations and then solving the corresponding equation through the timing incremental method and acceleration value separately. We can get two angles by solving the double integral values, then through the data fusion algorithm for two angle value processing to obtain the stable angle value. Verified, the results of this experiment have small error,had a high accuracy, stability and timeliness.

Abstract: This paper introduces a kind of low power ground temperature monitoring system based on CAN bus, the detection system adopts DS18B20 temperature sensor as the detecting element, under a machine with low power consumption of processor MSP430 MCU multi-channel temperature data collection, PC processors SMT32 is adopted to improve the data receiving and analysis. The ground temperature detection system has realized the low power consumption, strong anti-interference ability, low cost, has wide use value.

Abstract: During last years, IEEE 802.15.4 has been asserting itself as one of the most promising standards for Wireless Sensor Network. It includes a security sublayer, which provides a number of operations and procedures aimed at securing network communications. But providing security features and power consumption together face a trade-off. In spite of so many research works discussing IEEE 802.15.4 security service, so far not so many focus on their implementation and performance. This paper discusses some security aspects of IEEE 802.15.4, and presents a practical approach to secure point to point link between wireless sensor nodes in details, supporting all the security suites of the standard. The results demonstrated that our approach achieved significantly lower power consumption and higher performance in security.

Abstract: This paper introduces the design and implementation of the safe transmission mechanism of wireless sensor network. This scheme is aimed at reducing node’s cost of computing and communication. Firstly, the WSN will be clustered. Then, encryption key will be generated in the clusters, which is used of data encryption and decryption based on nodes identification to ensure data security. The system uses the wireless microcontroller CC2430/CC2431 to perform the simulation testing for program modules of Chipcon, which integrates CC2420RF wireless RF transceiver. Experimental results show that the new algorithm can increase traffic, node utilization and improve the confidentiality and security of sensor information.

Abstract: Wireless sensor networks have the characteristics of taking the data as the center, focusing on the functions and having no backbone structure. In this paper, a data-forwarding algorithm based on semantic-based routing is proposed, which is aiming at improving the routing efficiency and increasing the lifetime of the networks. First, we defined the semantics of networks, and constructed the expression architecture for semantics of wireless sensor networks. Then we used these semantics to compose data packets. Finally, we matched the semantics from the packets of networks, which determined the direction of packets forwarding. Experimental results show that the algorithm performed better than DD and LEACH. It can reduce energy consumption, redundant data and prolong the networks' lifetime.