基于分时复用原理的多通道探地雷达时序控制模块设计及应用  

Design and Application of Multichannel Ground-Penetrating Radar Timing Control Module Based on Time-Division Multiplexing Principle

作　　者：王百泉 刘昌斌 王华 张安学[3] 陈思宇[3] 谢韬 WANG Baiquan;LIU Changbin;WANG Hua;ZHANG Anxue;CHEN Siyu;XIE Tao(China Railway Tunnel Group Co.,Ltd.,Guangzhou 511458,Guangdong,China;Guangdong Provincial Key Laboratory of Intelligent Monitoring and Maintenance of Tunnel Structure,Guangzhou 511458,Guangdong,China;Institute of Electromagnetics and Information Technology,Xi′an Jiaotong University,Xi′an 710049,Shaanxi,China)

机构地区：[1]中铁隧道局集团有限公司,广东广州511458 [2]广东省隧道结构智能监控与维护企业重点实验室,广东广州511458 [3]西安交通大学电磁与信息技术研究所,陕西西安710049

出　　处：《隧道建设（中英文）》2022年第9期1637-1646,共10页Tunnel Construction

摘　　要：为实现对隧道衬砌空洞和地质病害的无损、高效检测,基于分时复用原理,通过FPGA编程和时序电路设计实现一种瞬态脉冲型多通道探地雷达时序控制模块,并应用于多频多通道隧道病害检测探地雷达系统。该时序控制模块可以产生多路同频等相位差时钟,分时触发各个通道脉冲信号的单次收发,从时间上分离通道间串扰信号和有效雷达回波,实现探地雷达多频段多通道的高效工作。试验测试和实地验证结果表明:该时序控制模块在脉冲重复频率为500 kHz时,能实现8通道雷达测试系统相邻通道间240 ns左右的触发时差,并在触发时差范围内保证观察时窗内雷达回波信号的稳定性;同时,该模块也能应用于3频段6通道隧道病害检测探地雷达系统,并在距离介质分界面65 cm时反映出实际隧道预埋病害的深度和尺寸信息。To achieve nondestructive and efficient detection of tunnel lining voids and geological diseases,a transient pulsed multichannel ground-penetrating radar timing control module based on the principle of time-division multiplexing is implemented through field-programmable gate array programming and sequential circuit design and applied to multifrequency multichannel tunnel disease detection ground-penetrating radar system.The proposed timing control module can generate multiple channels of clocks with the same frequency and equal phase difference to trigger a single transmission and reception of a narrow pulse source of each channel at different times,thereby separating the crosstalk signal between channels and the radar echo and resulting in an efficient system of multiband and multichannel ground-penetrating radar.The experimental test and field verification results show the following:(1)When the repetition pulse frequency is 500 kHz,the proposed module can implement about 240 ns difference between the trigger time of adjacent channels of an eight-channel radar test system.(2)This difference can ensure radar echo stability when the observation time is within the range of the trigger time difference.(3)The proposed module can also be applied to a three-band six-channel tunnel disease detection ground-penetrating radar system and reflects the depth and size of the actual tunnel disease when it is 65 cm away from the medium interface.

关 键 词：隧道病害检测 6通道探地雷达 时序控制模块 分时复用 

分 类 号：U45[建筑科学—桥梁与隧道工程]