Advanced Materials Research Vols. 765-767

Abstract: Based on the wireless sensor network technology, an environmental monitoring system with localization and magnetic detection capabilities is developed for unattended remote environment monitoring and control. In the system, monitoring nodes adopt the CC2420 to build a low-power, short-range jump, self-organizing wireless network, and the gateway node uses the GPRS technology to link the front monitoring network to the rear monitor center. Meanwhile, a component-based software framework is provided to facilitate the protocol implement and to improve expansibility. The experiment demonstrates that the supervisory system can realize the environmental control duty and has a good application value.

Abstract: Noise measurement is the important means on the noise monitoring, evaluation and control.At present the error of sound pressure method widely used is larger. It adopts the method of double microphone in the method of sound intensity measurement,and uses acoustic pressure gradient change to approximately equal the particle vibration velocity, spectrum density function is obtained by using sound intensity analyzer,it computes integral for Spectrum density function that are sound intensity.In this paper, by measuring sound intensity of ventilator and comparing the numerical results and experimental results, it confirmed that the method is high precision, has practical application value.

Abstract: Anti-lock Braking System (ABS) has widespread used depending on its mature technology and superior performance. We design a test rig which can simulate the running condition of wheels for ABS to detect the braking performance. The kinetic energy of vehicle is replaced by the kinetic energy of rotating flywheel, and the tire-road friction coefficient is replaced by magnetic powder clutch. The amplitude of exciting current to the clutch has linear relationship with the friction coefficient, so as to provide a datum for detecting the working status of ABS under various road conditions. The system can realize simulating test of single road surface, bisectional road surface and joint road surface. The validity of the road simulation method can be verified by the real-time data from the user interface.

Abstract: Yarn tension during weft insertion is one of important factors which affect fabric properties. In air jet loom, many components have an influence on yarn tension, such as clamp, main nozzle, sub nozzle, brake, and the drum. In this paper, a measurement system for yarn tension experiment which based on a 32-bit Cortex-M3 embedded processor was designed and implemented. The system can control components at fixed time interval which is set by a supervisory computer, acquire yarn tension converted by a contacted electromagnetic induction tension sensor, and then transmit tension data to software system by Ethernet module. An experiment is conducted for research character of yarn tension driven by air flow. The experiment results indicate that the nozzle pressure and yarn diameter play an important role in yarn tension during weft insertion on air-jet loom. Besides, the delay of magnetic value is also considered under different nozzle pressure.

Abstract: indirect vision driving for Vehicle is a kind of technology which lets the driver gets correct road information in order to ensure normal driving with the use of the camera and displays. After introducing the ergonomic theory of driving fatigue and the development of driving fatigue detection at home and abroad, mainly use EEG to judge the driving fatigue level of indirect vision driving. The experiment results show that greater fatigue is brought to the driver on the condition of indirect vision driving compared with the direct vision driving.

Abstract: Because the industrial control systems were often used in different manufacturers and different types of equipment, how to uniform the different equipment communication interface was a big problem. The real-time communication between Personal Computer and S7-200 PLC had been achieved by using the Siemens configuration software PC access and VC++ application programming. The pull detection system was designed by using this OPC method. In the paper the client design and the modular program design of the pull detection system were explained in details. At present, the system was used in the factory and it was running stable with good results.

Abstract: A novel Sagittarius automatic Pulsed I-V measurement system was developed. This new system eliminated the self-heating effect which affected static measurements of High Power MOSFETs using conventional methods. It provided the true output conductance and trans-conductance, solved the device modeling problems caused by negative output conductance of high power devices. The automation measurement function can fulfill the mass measurement requirements of semiconductor industry with high efficiency and accuracy.

Abstract: The key point of the proposed LED (light emitting device) optical field measurement system is to place the packaged or unpackaged LED on a stepping motor without any translation parts. Thus the mechanical aging effect and the maintenance problems of the traditional rotary part are avoided. Besides, the measurement sensors are fixed along a quarter arc of a circle with the LED at the center, so they can take both spectrum and energy output measurements along various aspect angles. The system has thirteen photo detector modules forming a 90° arch with a diameter of 63.2cm. Each module comprises eight photo-detectors, and each detector covers 0.9°. A stepping motor, placed at the center of the circle, rotates a LED under test through 360°with a step size of 1.8°. A powerful micro-controller (C8051-F020) is employed to control the 3-dimensional far field measurement flow for the data acquisition that bridges the photo-detector array modules and a personal computer. The communication between the personal computer and the data acquisition sub-system is through a RS232 interface. A fast, reliable, user-friendly measurement system has been achieved.

Abstract: In SMT solder paste deposit 3D measurement based on PMP, conventional phase unwrapping method suffered from shadow, noise and holes. Considering practical engineering condition, phase unwrapping method can be improved using 2D image information: basic principle method was applied to smooth area, quality-guided unwrapping and least-square method were taken in shadow or break area for phase unwrapping respectively. Experimental results show that desired phases can be correctly and quickly unwrapped in proposed method.

Abstract: The rev of vehicle transmission is an important parameter to reflect the performance of the power train, and the measurement accuracy will have an influence on the implement of electronic control technology in transmission system. Based on the analysis of common rev measurement methods, aiming at the feature of wide range of rev during HMCVT test, a method of rev equal precision measurement is been put forward.