To achieve the real-time detecting and localization of hypervelocity impact events, a monitoring and localization system was designed based on fiber Bragg grating (FBG) sensor network. First, the simulation model was built to study the damage evolution and wave propagation process. Subsequently, based on the response mechanism of FBG to strain, the corresponding high frequency demodulation system was designed. Furthermore, a hypervelocity impact experiment was performed to verify the effectiveness of the designed system. Finally, combined with the diamond sensor array localization algorithm, the accurate position of hypervelocity impact source can be achieved.

Using the acoustic emission locating technology to monitor the health of the structure is important for ensuring the continuous and healthy operation of the complex engineering structures and large mechanical equipment. In this paper, four fiber Bragg grating (FBG) sensors are used to establish the sensor array to locate the acoustic emission source. Firstly, the nonlinear locating equations are established based on the principle of acoustic emission, and the solution of these equations is transformed into an optimization problem. Secondly, time difference extraction algorithm based on the phase transform (PHAT) weighted generalized cross correlation provides the necessary conditions for the accurate localization. Finally, the genetic algorithm (GA) is used to solve the optimization model. In this paper, twenty points are tested in the marble plate surface, and the results show that the absolute locating error is within the range of 10 mm, which proves the accuracy of this locating method.

本文提出一种基于立体视觉的空间非合作航天器相对位姿自主测量方法, 用以解决在轨捕获中非合作航天器的相对位姿测量问题。该方法以航天器本体和星箭对接环作为识别特征, 识别过程无需人员参与; 同时, 提出一种基于空间几何约束的特征匹配方法, 运用空间几何约束引导匹配, 在完成匹配的同时可直接获取特征的三维信息, 实现特征匹配与重构的一体化; 最后, 利用空间向量对非合作航天器的相对位姿参数进行解算, 充分利用冗余信息, 以提高解算精度。实验结果表明, 在航天器本体尺寸为280 mm、相对距离为2 m的条件下, 本文方法的姿态测量误差小于1.5°, 位置测量误差小于4 mm, 能够满足空间非合作航天器在轨捕获的相对位姿测量要求。

为研究用于X射线脉冲星导航的探测系统性能,推导了在光子计数模式下探测系统的信噪比和最小可探测功率的关系表达式,并搭建测量信噪比和最小可探测功率的实验装置.测量了系统的最小可探测功率以及在不同光功率、不同累积时间和不同阈值电压条件下探测系统的信噪比.通过对X射线光子到达时间的测量,构造了X射线脉冲累积轮廓.实验表明: 随着光功率和累积时间的增加,累积脉冲轮廓的信噪比提高,累积脉冲轮廓趋于光滑;当阈值电压为-150 mV时,信噪比为26.3,累积脉冲轮廓最优;系统的最小可探测功率为3.5×10-16 W.