Design And Implementation Of Towered Transient Electromagnetic System For Unexploded Ordnance Detection

Unexploded ordnance generally includes unexploded ordnance deployed and used during combat and some military activities.And these hazards that have not been properly handled are a serious threat to the personal safety of local residents.So far,several common geophysical methods such as magnetic detection,electromagnetic detection,infrared detection,and ground penetrating radar have been developed successively.Among them,the time-domain electromagnetic method(ie,transient electromagnetic method)is gradually accepted by people due to its strong anti-interference ability,unaffected by geological conditions,low false alarm rate,and large detection depth.Based on this method,various UXO detection systems have been developed successively,such as portable system,towed unexploded ordnance detection system,and airborne system.Among them,the towed unexploded ordnance detection system has a very high spatial resolution and a wide dynamic measurement range.It is widely used to detect underground unexploded ordnance activities.At present,the domestic research on this type of detection system is very limited,and there is no relatively mature related system,so it is of great significance to the research and development of the unexploded ordnance detection system.The main content of the paper is the design of the towed unexploded ordnance detection system.The main research contents are as follows:First of all,this paper comprehensively introduces the current status of research on UXO detection at home and abroad,compares the research results in this direction at home and abroad,and explains the domestic research on the towed unexploded ordnance detection system.Explain the significance of this study.In the second chapter of this paper,the basic theory of transient electromagnetics is introduced and discussed.The basic composition and preliminary design scheme of the transient electromagnetic system are discussed.Trapezoidal pulse current,which is easier to realize,is selected for the emission current.The system uses the method of overlapping loops to construct the sensor array.At the same time,the work flow of the TEM and the preliminary data processing flow are given.Secondly,based on the above theory,a towed unexploded ordnance detection system is designed.The system includes a sensor that can realize three-component transmitting and receiving,wherein the relevant parameters of the transmitting and receiving parts of the sensor are:wire diameter,side length,number of turns and resonance frequencies of 2.5mm~2,96cm,25 and 270KHz respectively The transmitting coil and wire diameter,side length,resonant frequency and off-time are respectively 0.17mm~2,0.06m,50KHz and 40us receiving coil.At the same time,a host system is also designed,which can realize the high-current driving of the transmitting coil and the acquisition,processing and display of 30 channels of received signals.Finally,in order to verify the performance of the system designed in this paper,the performance test and field test are carried out.The experimental results show that the transmitting current of the system can reach 15A,and the effective area of the receiving coil can reach 290m~2 on average.The system can accurately detect the target with a buried depth of 2m and the positioning error is not more than 10cm.