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Shijiazhuang, China

Li J.,Ordnance Engineering College
Guangdian Gongcheng/Opto-Electronic Engineering | Year: 2010

The mechanism of precision tracking turntable was designed. The entity model of the precision optoelectronic tracking turntable frame was established and the static and dynamic analysis of the precision turntable was done by using the software ANSYS. The static analysis results show that the intensity and rigid requirements of tracking turntable frame were satisfied. The mode analysis indicated that the precision optoelectronic tracking turntable frame had good dynamic characteristics, and synonym did not occur. The rationality of turntable frame was validated by analysis results, and it provided the important evidence for the optimization design of precision optoelectronic tracking turntable. Source

Gao H.C.,Ordnance Engineering College
Advanced Materials Research | Year: 2013

Due to the emergence of more and more composite armor target, the research related with interval has real application background. The target board with interval structure form attenuates jet penetration effectively. If the interval target and homogeneous target can build equivalent relations, with a certain thickness of the interval target equivalent instead of a homogeneous target board, it will slash test cost and save money. After the target principle and research method, the jet penetration interval target for energy consumption, the jet penetration depth interval target researches are simple introduced, finally the research direction of interval target is put forward with own suggestions. © (2013) Trans Tech Publications, Switzerland. Source

Lu B.,Ordnance Engineering College
Dianbo Kexue Xuebao/Chinese Journal of Radio Science | Year: 2013

Aiming at the problem of target effect in sidelobe canceller, polarization filtering technique based on oblique projection operator is introduced into sidelobe cancellation system, and a new method to eliminate target effect is presented. This new method estimates jamming signal polarization parameters, and calculates oblique projection operator; The calculated oblique projection operator acts on accessory channel echo, as a result, the jamming signal extracted from the echo and target signal is entirely rejected. Compared with normal polarization filtering methods, this new method can reject target signal entirely and improve cancellation ratio greatly, only jamming signal polarization parameters needed. Theory analysis and computer simulation prove the validity of this method. © 2013 by Editorial Department of Chinese Journal of Radio Science. Source

Ma L.,Ordnance Engineering College | Kang J.,Ordnance Engineering College | Meng Y.,Hebei Electric Power Research Institute | Lv L.,62191 Troops of PLA
Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument | Year: 2013

Aiming at the problem that at early stage of bearing fault, the feature components of the original vibration data are easy to be submerged in noise signal and can not be detected in time. According to the de-noising principle of Morlet wavelet transform, a method is presented, which determines the optimal scale parameter based on scale related power distribution, so that the signal is filtered under this scale and the impact feature components are extracted. The main filtering procedures include: the minimum Shannon entropy is used to optimize the Morlet wave shape factor, the best match between mother wavelet and signal fault feature is realized; the scale-power spectrum is plotted with the wavelet transform coefficients of the best Morlet continuous wavelet under different transform scales; and according to the accumulative characteristic of the fault feature power in specific scale range, the scale parameter with best filtering effect is selected from the extreme points in the scale power spectrum. The actual processing result for bearing full lifetime vibration datasets shows that the proposed method can extract the weak feature components and detect the existence of related outer-race fault in advance compared with root-mean-square trend. So this method can be regarded as an effective approach for diagnosing bearing incipient fault. Source

Li H.,Shijiazhuang Railway Institute | Zheng H.,Ordnance Engineering College | Tang L.,Ordnance Engineering College
Zhendong Ceshi Yu Zhenduan/Journal of Vibration, Measurement and Diagnosis | Year: 2013

According to the shortcomings of traditional dual-tree complex wavelet transform which has spectral aliasing, a novel approach to multi-faults diagnosis of bearing based on improved dual-tree complex wavelet transform is presented. Firstly, the bearing fault vibration signals are decomposed into various frequency band signals. Then the band signals are decomposed using empirical mode decomposition technique, and the maximum energy component is found. In the end, the envelope spectrum of maximum energy components is computed. Therefore, the characteristics of the bearing faults can be recognized according to the envelope spectrum. The simulative and experimental results show that not only the spectral aliasing is eliminated, but also the frequency band selection accuracy and signal noise ratio are improved, the multi-faults of the bearing can be effectively detected. Source

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