Real-time double-laser-stripes measurement system for subway tunnel profile based on high-speed vision

摘要

Tunnel profile measurement is an important technology for safety of subway operation, and triangulation system with lasers and cameras has been a key research direction. To increase the accuracy of profile detection, this paper proposes a real-time double-laser-stripes measurement system, which can obtain 600 profiles per second by using high-speed vision system. Image processing algorithm of double-laser-stripes extraction is designed and implemented on FPGA (Field Programmable Gate Array) at 300fps with resolution of 1280 × 1024 pixels. Sub-pixel position of laser-stripes is calculated and recorded to PC memory at high-speed. A calibration method is described to obtain the world coordination. To verify the algorithm, a local measurement system is developed on a high-speed vision platform, using one camera and two laser generators. All the detection sensors are equipped on a slideway to simulate subway movement.