Research And Implementation Of Grid-Topology Map Construction Algorithm Based On Lidar

Currently,mobile robots are widely used in security patrols,healthcare and life services.Before performing the task,the external environment information needs to be acquired through the sensor installed on the body to create a map of the environment.However,the current mainstream environmental maps cannot meet the needs of mobile robots for mapping and navigation in large-scale environments.so this thesis proposes a method based on lidar sensor to construct grid-topology map.The specific research is as follows:(1)An algorithm for improving the accuracy of pose estimation of mobile robots is proposed.Because the GMapping algorithm is not accurate enough to construct the grid map,the high-frequency laser is used to realize the pose estimation of the mobile robot.Firstly,the particle filter method is used to sample the odometer pose estimation to realize the initial estimation of the pose of the mobile robot.Based on this estimation,the Adjacent two-frame lidar scan data is registered using the fast ICP algorithm to obtain an accurate estimation of the pose of the mobile robot.Finally,a grid map is created using the improved accurate pose estimation.In this thesis,the advantages of the fast ICP algorithm compared with other methods are verified in the real environment.At the same time,the grid map created by the improved GMapping algorithm based on pose estimation is proved to have higher precision.(2)Designed a method for constructing a grid-topology map.This thesis first studies the extraction of corner features based on grid maps,and extracts corner and line segment features based on lidar scan data.Then Monte Carlo positioning is used to obtain the pose of the mobile robot in the grid map at the moment.Finally,the feature extraction based on the grid map and the scanned data is combined,the channel information is identified,and the topology nodes are extracted to create a grid-topology map.(3)Implement a grid-topology map construction system GT_Mapping based on lidar.The overall architecture of the GT_Mapping system is given,and the main functional modules are described in detail.The system is developed under the robot operating system.It is proved that the system can accurately generate the grid-topology map.