| The quadrotor forestry information monitoring can be divided into the above canopy monitoring and under canopy monitoring.Compared with the above canopy monitoring method,the UAVs fly under the canopy always face multiple challenges including weak GPS signals,dense and randomly distributed obstacles as well as similar environmental characteristics.Therefore,in view of the actual needs of UAVs in the canopy flight tasks,this paper proposes the simultaneous localization and mapping technology based on monocular vision and laser radar fusion.The major work of this thesis is presented as follows.1.A SLAM algorithm based on monocular vision and laser radar fusion was improved and researched.In this paper,a pose and position estimation algorithm based on monocular odometer was used to estimate pose and position.The pose and position information of the monocular odometer was used to match the laser data in the laser map construction,therefore the depth map of the obstacle was obtained.The map was optimized by GraghSLAM based on the partial optimization method.Then cost map of obstacles was generated by using Gaussian Blur method.2.In this paper,the improved SLAM algorithm was simulated and evaluated in ROS simulation platform.This paper compared the SLAM proposed in this paper with other classical algorithms.Then,a simulation flight experiment is carried out to verify that the SLAM algorithm proposed in this paper can provide position and pose information and map information for navigation planning in real time.3.The simultaneous localization and mapping system for quadrotor was designed and built,then the system was tested under canopy environment.The experimental results showed that the quadrotor designed in this paper can realize simultaneous localization and mapping goals under canopy environment.This paper improved the SLAM algorithm based on monocular vision and laser radar fusion,realized the simultaneous localization and mapping under the canopy of quadrotor,and provided security guarantee for the monitoring of the quadrotor under the canopy. |
