Applied Mechanics and Materials Vols. 713-715

Abstract: The collision detection problem is a classical problem in computer graphics research field. It has become a hot topic in recent years with the development of virtual assembly technology. And accurate collision detection is crucial to improve the reliability and authenticity of virtual assembly. In this paper, we designed a collision detection algorithm with a pre-segment strategy based on OBB-Tree algorithm, took advantage of the shape characteristics of component model, used a smaller bounding box for operation. Experimental results showed that the efficiency of the algorithm is about 10% higher than that of traditional OBB-Tree algorithm.

Abstract: An edge detection method based on adaptive differential operator is proposed in this paper. Firstly, standard local edge models are built. And these edge models are described with four-bit-binary code (FBBC) which is obtained from weighted mean values in four directions. Then, based on weighted gray values in four directions, different differential operator templates are defined. And FBBC is used to build the matching between differential operator templates and edge models. Experiments show that this edge detection method with adaptive differential operator can smooth noise and has satisfactory edge detection result.

Abstract: This document describes the architecture of a tracking system with two degrees of freedom (pan and tilt), endowed with artificial vision to follow the path of a moving object. The mechanism with a fixed base was designed to cover lateral and vertical ranges of movement, similar to the visual field in humans, limiting its depth by the resolution of the camera. The object that defines the motion path presents color uniformity across its surface, becoming the main feature in which the recognition and tracking algorithm were based. The tracking is performed by reducing the error between the object position and the reference axis of the camera. Several tests were carried out to evaluate the control and visual systems and to illustrate the behavior of the proposed methods.

Abstract: The pointing of an antenna always exists deviation due to track deformation, gravity and thermal influence. Through long time observation, we find that sunlight also has some influence on antenna structure. In order to get the antenna pointing deviation in the effects of the sunlight of 25m antenna in Urumqi, we use the frame-typed level and thermometer to make a week’s measurement about the temperature around the antenna and the antenna tilt. The measured data was analyzed and combined with the track deformation data, and the pointing error fixed model as well as the thermal load deformation model were built. The measured data was fitted by the two models, and the result shows that the model can well reflect the pointing error and thermal load error, thus can give a better understanding of the antenna deformation, and also can give some good reference to antenna pointing calibration and the antenna’s reconstruction.

Abstract: STC89C52 single-chip microcomputer is used as control core of the system, and characteristics of photoelectric switch is used to design a scheme for detection of face value of coins based on different sizes of coins. Genuine coins and counterfeit coins have different size and mass, based on which the combination of strain sensor and photoelectric switch is put forward to design a scheme for identifying genuine coins and counterfeit coins. In this paper, hardware and software design of the system is introduced in a detail way and system testing is conducted at last, the result of which indicates that the system can realize the identification, classified statistics, sound and light prompting for coins with different face values as well as identification of genuine coins and counterfeit coins, and thus has a certain degree of prospect for application and value of promotion.

Abstract: There are two modes of line monitoring system application in the rural distribution, the point to point and the cascade. Comparison of two modes’ construction architecture and the advantages, disadvantages are analyzed. It puts forward two kinds of modes application limitations. The construction area according to the matching function, scheme and the device type should be present.

Abstract: Intelligent sensing system for distribution line condition monitoring is presented. It uses sensing terminals to detect load current, temperature, humidity and water pass state. It uses intelligent sensor to collect the distribution condition information. The information collected by the terminals transmits to intelligent sensing system. It is designed without the need for primary equipment reform, without the need of large-scale construction of communication channel, without the need for power blackout with small investment and big benefit. It greatly improves the power supply capacity, efficiency of the system accident treatment and the reliability of power supply.

Abstract: In this paper, the author introduces the principles of wavelet packet denoising, conducts a simulated analysis on the improved performance of wavelet packet denoising and develops the source Matlab program. In addition, the measured acoustic signals of seafloor sediments are denoised using wavelet packet. It is feasible to apply the wavelet packet denoising technique in a wide range of engineering testing fields involving denoising operation.

Abstract: Based on mode acoustic emission theory, the paper uses dynamic finite element software ANSYS / LS-DYNA to simulate modal acoustic emission test, and obtains the Lamb wave propagation analog signal on sheet plate; By analyzing the analog signal, it determines the signal frequency and the Lamb wave arrival time of signal receiving point, then determines the guide wave group velocity at this frequency, and uses the method of time difference analysis to determine the dispersion curve. Comparing the simulation dispersion curve with the theoretical curve, the study has shown both curves are consistent and it is feasible to simulate modal acoustic emission signals with the finite element.

Abstract: This paper is based on the engine fault diagnosis technology and the network technology, it carries out and uses the Internet network data transmission engine to obtain technical parameters of the engine,fault diagnosis of engine remote.The system can discover the fault of automobile engine and to determine repair method, the fault and exclusion, effectively improve the flexibility and accuracy of fault diagnosis, remote resource sharing.