Abstract: Noise and crosstalk in post-earthquake multi-life location system can result in false location and decrease the work efficiency of system. To improve the performance of multi-life location system, the chaotic codes with Binary Phase Shift Keying（BPSK） method is proposed to construct the spread spectrum emission signals for ultrasonic sensors. Correlation technique in the receiving circuit is used to de-spread. To obtain the optimal correlation performance, the genetic algorithm is applied to optimize chaotic initial values of Ulam-von Neumann transformation. In simulated post-earthquake environment, experimental verification of ultrasonic multi-life location system with optimized spread spectrum emission signal is carried out. The experimental results demonstrate that the proposed method can realize multi-life location simultaneously with maximal 3.9 cm absolute error.

Key words: post-earthquake life detection, ultrasonic, multi-target location, signal optimization

摘要： 震后超声多生命体定位系统受到噪声及串扰的影响导致错误的定位结果并降低系统的工作效率。为提高超声多生命体定位性能，提出了混沌编码和二值相移键控调制法构造超声传感器发射端的扩频发射信号，相关技术被用于接收端解扩。为获得最佳的相关效果，采用遗传算法优化Ulam-von Neumann变换混沌序列初值。在模拟震后环境中，优化扩频发射信号作用于超声多生命体定位系统进行了实验验证。实验结果表明，所提优化扩频发射信号可实现多个生命体同时定位，定位绝对误差在3.9 cm以内。

关键词: 震后生命探测, 超声, 多目标定位, 信号优化