title: A noncontact FMCW radar sensor for displacement measurement in structural health monitoring.
abstract: This paper investigates the Frequency Modulation Continuous Wave (FMCW) radar sensor for multi-target displacement measurement in Structural Health Monitoring (SHM). The principle of three-dimensional (3-D) displacement measurement of civil infrastructures is analyzed. The requirements of high-accuracy displacement and multi-target identification for the measuring sensors are discussed. The fundamental measuring principle of FMCW radar is presented with rigorous mathematical formulas, and further the multiple-target displacement measurement is analyzed and simulated. In addition, a FMCW radar prototype is designed and fabricated based on an off-the-shelf radar frontend and data acquisition (DAQ) card, and the displacement error induced by phase asynchronism is analyzed. The conducted outdoor experiments verify the feasibility of this sensing method applied to multi-target displacement measurement, and experimental results show that three targets located at different distances can be distinguished simultaneously with millimeter level accuracy.
authors.affiliation: College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China. licunlongcqu@126.com.|Key Laboratory for Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China. licunlongcqu@126.com.
authors.forename: Cunlong
authors.initials: C
authors.lastname: Li
authors.affiliation: College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China. wmchen@cqu.edu.cn.|Key Laboratory for Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China. wmchen@cqu.edu.cn.
authors.forename: Weimin
authors.initials: W
authors.lastname: Chen
authors.affiliation: School of Civil Engineering, Chongqing University, Chongqing 400045, China. gliu@cqu.edu.cn.|Key Laboratory of New Technology for Construction of Cities in Mountain Area, Ministry of Education, Chongqing University, Chongqing 400045, China. gliu@cqu.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.affiliation: College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China. yanrongcqu@126.com.
authors.forename: Rong
authors.initials: R
authors.lastname: Yan
authors.affiliation: College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China. hyxu0802@cqu.edu.cn.
authors.forename: Hengyi
authors.initials: H
authors.lastname: Xu
authors.affiliation: College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China. cqu_yiqi@cqu.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Qi
mesh_terms: D000465:Algorithms; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011825:Radar / Q000295:instrumentation*
references.citation: Sensors (Basel). 2008 Sep 24;8(9):5866-5883
references.pmid: 27873846