摘要
在地铁隧道等退化场景下,主流的激光或视觉SLAM算法实用性低,无法有效完成三维重建工作。该文提出一种基于路径似然模型(PLM)与隐马尔可夫(HMM)序列匹配的大规模地铁隧道三维重建方法,将三维重建问题分解为里程计定位与基于图优化的高精度三维重建两个过程。针对里程计定位,该文提出一种融合路径似然模型的里程计方法。在粒子滤波框架下,将轨道约束转化为观测,并与IMU和轮速计数据融合,实现在轨机器人定位。此外,还提出一种基于HMM序列匹配的回环检测方法,将回环检测问题转化为序列匹配问题,提升回环检测的性能。针对重建问题,提出一种基于大规模因子图优化的三维重建方法,通过多约束条件完成位姿图优化,从而实现大规模地铁隧道的高精度三维重建。在成都韦家碾-双水碾和沙河源-洞子口两段地铁站之间进行了实地测试。实验结果表明,该文提出的PLM和HMM序列匹配可以有效提升里程计定位精度和回环检测性能,从而实现大规模地铁隧道场景的高精度三维重建。
Objective As the operational mileage of metro systems in China continues to increase,the inspection and maintenance of metro tunnels have become more critical.Accurate 3D reconstruction of metro tunnels is essential for construction,inspection,and maintenance.However,in severely degraded tunnel environments,existing SLAM algorithms based on laser or vision often struggle to construct maps and face limitations in complex scenarios.To address this challenge,this paper proposes a method for large-scale 3D reconstruction of metro tunnels by utilizing the matching of the Path Likelihood Model(PLM)and the Hidden Markov Model(HMM).The 3D reconstruction task is divided into two key processes:odometer positioning and high-precision 3D reconstruction via graph optimization.High-precision 3D reconstruction is achieved by effectively addressing both components.Methods For odometer-based localization,this paper presents a method that incorporates the PLM.The PLM is developed using kernel density estimation to analyze the vehicle’s track path,effectively representing the vehicle’s positional information as a probability distribution.Within the framework of a particle filter,this method converts the constructed PLM into position observations of the vehicle.Additionally,data from the onboard Inertial Measurement Unit(IMU)and the wheel speed sensor are integrated to enhance localization accuracy.To minimize cumulative errors in odometer-based localization,this paper reformulates the problem of loop closure detection as a sequence matching problem using the Viterbi algorithm within the framework of the HMM.This method effectively addresses the instability associated with single-frame matching in loop closure detection and significantly improves the overall performance.To resolve the reconstruction problem,this paper presents a method for 3D reconstruction using large-scale factor graph optimization.By optimizing the pose graph with multiple constraints,it enables high-precision 3D reconstruction of extensive metro tunnels.Results and Discussions The proposed method and model are tested and validated at the WeiJianian-ShuangShuianian and ShaHeyuan-DongZikou metro stations in Chengdu.The experimental results are as follows:the effectiveness of the proposed method is confirmed through two sets of ablation experiments,DR and DR+PATH.Furthermore,by comparing the results with those of two notable open-source LIDAR algorithms,LIO-SAM and Faster-LIO,the superiority of this method is demonstrated.The reconstruction accuracy achieved is high,and the reconstruction error remains consistent even as the running distance increases.Therefore,the method is suitable for application in real operational processes.Conclusions This paper addresses the challenges of 3D reconstruction in metro tunnels by proposing a novel algorithm that combines the PLM with HMM sequence matching.The PLM is developed using drawing information,which serves as the foundation for the reconstruction process.Within the framework of particle filtering,the likelihood model is used to correct errors from the IMU and wheel speed sensor.This results in accurate odometer readings for the onboard robot.Furthermore,the issue of loop matching is reformulated as an HMM sequence matching problem.By constructing loop constraints,accumulated positioning errors are effectively eliminated.Finally,the pose and loop constraints derived from the odometer data are integrated into the optimization model for a large-scale factor map,enabling high-precision 3D reconstruction of the metro tunnel.Field tests conducted at the WeiJianian-ShuangShuianian and ShaHeyuan-DongZikou metro stations in Chengdu,with comparisons with other algorithms,demonstrate that the proposed PLM and HMM sequence matching algorithm significantly improve 3D reconstruction accuracy in metro tunnels,particularly in severely degraded environments.
作者
胡钊政
王书恒
孟杰
冯锋
朱紫威
李维刚
HU Zhaozheng;WANG Shuheng;MENG Jie;FENG Feng;ZHU Ziwei;LI Weigang(Intelligent Transport System Research Center,Wuhan University of Technology,Wuhan 430070,China;School of Information Engineering,Wuhan University of Technology,Wuhan 430063,China;China Construction third Bureau Information Technology Co.,LTD.,Wuhan 430074,China;Engineering Research Center for Metallurgical Automation and Measurement Technology of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China)
出处
《电子与信息学报》
北大核心
2025年第7期2273-2284,共12页
Journal of Electronics & Information Technology
基金
国家自然科学基金重点项目(52332010)
中建三局横向课题(20233h0392)
武汉科技大学冶金自动化与检测技术教育部工程研究中心开放基金。
关键词
地铁隧道
退化场景
路径似然
序列匹配
因子图优化
Metro tunnels
Degenerate scenarios
Path likelihood
Sequence matching
Factor graph optimization
