A Tunnel Cross-Section Detection System Based On Laser Ranging Technology

Transportation system is a key factor which concerns the development of the national economy, and plays a very important role in construction and development of the politics, culture and national defense security. Along with the development of the economy, China’s highway, railway, subway and other transportation systems have developed rapidly and vigorously, and the traffic projects under the construction are increasing. The tunnel has played a vital role in the process of building the traffic systems; therefore, the tunnels’ safety has become an inevitable problem during the construction and operation of those tunnels. As one of high risk projects where the engineering accidents occurred frequently, a tunnel which is undering construction always need to be checked whether there are crown settlement, wall rock deformation, surrounding rock instability and so on. Aiming at these problems, only to find out in advance and alarm in time are the best way to avoid the occurrence of tunnel accidents.It usually requires manual operation in the traditional tunnel monitoring and maintenance. Although the detection accuracy is not affected, this makes the detection inefficient, and consumes a large amount of manpower and material resources. Moreover, the shortcoming of that way is tunnel monitoring and tunnel safety pre-warning is not in time.This thesis proposes a tunnel cross-section detection system based on laser ranging technology against the deficiencies of traditional tunnel monitoring methods.This system not only could achieve real-time monitoring for gas concentration and the tunnel section for all day, but also can quickly response and timely alert to the exceptional cases in the tunnel. Besides, it would position the location where the problem occurs fastly and accurately, and notify the monitoring center to take appropriate measures to deal with it. Compared with the traditional tunnel monitoring system, this system has the advantages of high efficiency, accuracy, low cost, high automation and so on. It is of great significance to the pre-warning of the safety accidents in tunnel.Firstly, the overall requirements of the tunnel section monitoring system is analyzed in this thesis, and the tunnel monitoring scheme is designed combined the principle of laser distance measurement with the influence of the gas on the tunnel safety. Secondly, the functional requirements of the system are achieved through the realization of the hardware and software.The hardware includes the choice of electronic components, circuit schematic design, PCB design, welding and circuit debugging. The software work includes completing the driver projects of each module with C/C++, collects tunnel section data, gas data and transfers them to the host computer. Finally, the simulation test platform was built in the laboratory environment to test the system. Moreover, the feasibility and effectiveness of the system are verified, which meet the needs of tunnel section monitoring.