Research on the dual-source laser monocular ranging method for UAV inspection of bridge pier cracks

The realization of UAV path planning through a ranging system is one of the key technologies for fully automatic bridge pier inspection. Taking into account the working environment, cost factors and system complexity of the bridge pier inspection equipment, the author designed an embedded ranging system with ARMv7-A as the core and a dual-source laser sensor and CMOS sensor as the core devices for collaborative ranging. On this basis, the characteristics of the dual-source laser spot are used to accurately divide the region of interest (ROI), and the spot centroid coordinates are extracted to achieve monocular ranging in a complex environment. Experiments show that the system has a measurement error of 0.4% and a range of 220 cm. It has the characteristics of good accuracy, strong stability, high convenience and low cost. This provides a new solution for path planning of fully automatic bridge pier inspection.