Abstract:The daily inspection of underground cable trenches is labor-intensive and has dangerous risks, which is an urgent problem to be solved to maintain the stability of urban power system. Intelligent inspection robot system is the trend to solve this problem. Synchronous positioning and real-time map construction capabilities are the prerequisite for autonomous inspection of underground cable trench robots. The underground cable trench has the characteristics of bottom texture, structure, complex road roughness, poor GPS signal and other scenes. The map degradation and positioning accuracy decrease often occur when the inspection robot builds the structured scene. To solve the above problems, a multi-sensor SLAM system is designed, which integrates the data of 2D LiDAR, inertial measurement unit and wheeled odometer, and optimizes the robot odometer through adaptive initialization. An adaptive inter-frame registration method is designed to correct the matching errors of adjacent laser key frames under different pavement flatness. Field tests show that the degradation rate and location error of the proposed method are reduced by 7.42% and 8.73% compared with the existing methods in the complex underground cable trench scenario.