Applied Mechanics and Materials Vols. 602-605

Abstract: In order to detect targets accurately in electromagnetic environment, a decomposition of time reversal operator method for detecting targets with uniform circular array (UCA) is proposed in this paper. In this method, the time reversal operator in UCA is obtained by the transmission functions of targets and antenna array. And then, the eigenvector decomposition of time reversal operator is performed. According to the eigenvectors and the transmission functions of targets and scanning points in the given targets area, the focusing values of all scanning points are calculated, and the direction of scanning points whose focusing values are far greater than others are the direction of targets. Finally, the simulations verify the effectiveness of the proposed method.

Abstract: . The traditional radar antenna pattern measurement has high cost and complex procedures. With the flexibility and low cost of small rotor UAV, we propose a new radar antenna pattern measurement based on UAV platform. In the following we will analyze the traditional radar antenna pattern measurement techniques and its shortcomings. Then we suggest a solution based on UAV and expound the key technologies. At the end we analyze the difficulties and errors that may occur in engineering practices, which provides basis for the next project implementation.

Abstract: Misjudgment often occurred in low contrast remote sensing images, because most widely used image segmentation algorithms often have a larger threshold. To overcome this problem, a novel coastline detection algorithm is proposed. A restriction function is involved into conventional iterative selection process. According to langrage multiplier, a modified iterative selection model is formulated. This modified method utilizes the gradient of images to obtain an optimal threshold. A region grouping rule is proposed to distinguish land and sea. Experimental results show superior performance of proposed method in terms of accuracy. As an application, our method has been applied to extract the coastline of the remote sensing image with promising results.

Abstract: This paper introduces the development of FM simulcast, as well as the specific implementation methods and requirements of FM simulcast system for "Triple Same" and "One Guarantee". Finally, this paper takes the same frequency overlay network of JingJinTang highway as example, furthermore, details the FM simulcast system how to accomplish the testing of the same frequency, the same modulation, the same phase and cover the field strength.

Abstract: In order to solve the navigation system failure is difficult to detect small amplitude mutation problem, we proposed a model based on FM Gauss wavelet transform. The method uses the FM gauss wavelet transform values for real-time fault detection. It through simulation experiments completed analysis of the performance of the algorithm validation. The results show that the algorithm can effectively carry out fault diagnosis, it not only for large mutations detected fault but also has a good effect on the value of mutations fault and has slightly better detection results.

Abstract: The main impact of multipath effect on low-altitude radar measurement is elevated in this paper. The influence of multipath effect on monopulse radar measurement of elevation is analyzed. Examples suggest that the multipath error caused by the signals from pattern main lobe of radar antenna should be mainly considered in the actual project. According to the three elevation range of reflected signal entering the radar beam area, the multipath error model of elevation is established. The problem of anti-multipath interference for low-altitude target tracking with radar is solved by analyzing the error source which causes multipath effect.

Abstract: A new type of tachometer carbon brush wear detection technology is proposed based on data acquisition and signal processing technology, the key of which is that the tachometer carbon brush output information is acquired and processed, moreover, the real time conditions of the carbon brush wear are detected and analyzed based on the time domain Eigen value analysis method. During the data processing process, the results of the dimensional parameter processing method are compared with the results of the dimensionless parameter processing method at the same time. Then, we find that the detecting precision is greatly promoted and measurement probability is guaranteed by reasonable threshold selection. Experimental results indicate that the technology proposed here has high stability, high reliability, and high detecting probability, which has great practical value and deserves being extended widely.

Abstract: The functions and approval test requirements of the GCS were introduced. The composition and working principle of DEWE 2010, a portable data acquisition system, were presented, which provides a feasible technological approach for software demodulation of AM signals in GCS testing. On researching the principles of AM signal modulation, two novel coherent and non-coherent software demodulation methods for AM tracking error of GCS were devised with mixed programming of LabWindows and MatLab. Test and simulation results show that the measuring accuracy and automation level of novel AM tracking error testing approach meet the requirements of test measurement.

Abstract: Aiming at the characteristics of tool wear, a method is put forward for rapid detection, Firstly, extracted the tool image gray feature and formed gray feature image; Secondly, approximate sub-graph of three layers wavelet decomposition is treated by center-surround difference operations; On this basis, the significant images is formed by the fusion of feature saliency map. Finally, tool wear is detected through the segmentation method of oust variance and eliminated background texture information by region growing method. The experimental results show that the method can be effectively used in the monitoring of tool wear.

Abstract: The acquisition system realize custom on the equipment component detection based on multi-source heterogeneous parameters by .NET framework of WCF technology, real time automatic acquisition, real-time transmission, to solve the data acquisition and transmission of multi-source heterogeneous data. Acquisition system using this technology is real-time, good integration, scalability, high efficiency.