悬浮式矢量边发、边收声诱饵关键技术

现代＂智能＂鱼雷的一种对抗手段是发射诱骗编码寻的信号,因此需要相应发展＂智能＂的对抗器材。边发、边收声诱饵在发射应答信号时,不关闭接收机,从而可以不受诱骗编码的欺骗,在发射强干扰的同时测量鱼雷寻的信号的频率,来控制发射频率自动跟踪鱼雷寻的频率的变化,增强声诱饵的对抗能力。对于悬浮式声诱饵,边发、边收的关键技术是抗发射声串漏、界面反射声及混响的干扰。讨论了悬浮式矢量边发、边收声诱饵的组成和信号处理方法,利用矢量传感器的零点指向性抑制强干扰,可以使诱饵发射时也能探测微弱的寻的信号,并能测量鱼雷寻的信号的频率。     

车轮螺栓装配滑扣原因分析

一批车轮螺栓出现装配滑扣现象。质量检验结果表明，同批次螺栓的尺寸公差符合图样技术要求；螺栓的金相组织和硬度合格，螺纹处无其他缺陷，但镀铬层差异较大。分析主为，镀铬层厚度超差、镀层不均匀和镀层与基体材料硬度不匹配，造成螺栓在装配受力时镀铬层剥落、堆积直至挤伤螺纹引起滑扣。     

脉冲信号被动定位时延差估计方法研究

从三点法定位原理出发,在分析时延差估计误差与时延估计误差关联性的基础上,通过将信道修正技术引入过门限时延差估计(直接法),改善时延差估计的稳定性,得到了改进的过门限时延差估计方法(修正法).在研究分析信号时延与相移内在关系的基础上,根据误差理论,在高精度相位估计前提下,利用各相关参数估计误差对时延差估计误差的贡献大小以...     

Research on Estimation of Time Delay Difference in Passive Locating for Impulse Signal

Analyzed the relation between time delay difference and time delay estimation errors, based on the principles of three-point locating, a reformed threshold method for time delay difference estimation of impulse signals, called as amendment estimation for short, is developed by introducing channel equalization technique to its conventional version, named as direct estimation in this paper, to improve the estimation stability. After inherent relationship between time delay and phase shift of signals is analyzed, an integer period error compensation method utilized the diversities of both contribution share and contribution mode of concerned estimates is proposed under the condition of high precision phase lag estimation. Finally, a cooperative multi-threshold estimation method composed of amendment and direct estimations to process impulse signals with three thresholds is established. In sea trials data tests of passive locating, this method improves the estimation precision of time delay difference efficiently. The experiments verify the theoretical predictions.     

基于PC系统的手指静脉识别算法研究与应用

通过分析人体手指静脉图像的特点,提出了一种基于灰度谷形区域搜索的手指静脉提取方法,即利用手指静脉图像的灰度剖面曲线呈谷形特征来实现静脉特征的提取.在静脉模式识别中,改进了传统的模板匹配方法,并建立了一个基于PC系统的手指静脉身份认证系统用于测试算法.试验结果表明,该手指静脉提取和匹配算法具有较高的识别率和应用价值.