Purdue University Graduate School
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posted on 2020-05-07, 18:02 authored by Benhao WangBenhao Wang

Today, computer science and robotics have been highly developed. Simultaneous Localization and Mapping (SLAM) is widely used in mobile robot navigation, game design, and autonomous vehicles. It can be said that in the future, most scenarios where mobile robots are applied will require localization and mapping. Among them, the construction of three-dimensional(3D) maps is particularly important for environment visualization which is the focus of this research.

In this project, the data used for visualization was collected using a vision sensor. The data collected by the vision sensor is processed by ORB-SLAM2 to generate the 3D cloud point maps of the environment. Because, there are a lot of noise in the map points cloud, filters are used to remove the noise. The generated map points are processed by the straight-through filter to cut off the points out of the specific range. Statistical filters are then used to remove sparse outlier noise. Thereafter, in order to improve the calculation efficiency and retain the necessary terrain details, a voxel filter is used for downsampling. In order to improve the composition effect, it is necessary to appropriately increase the sampling amount to increase surface smoothness. Finally, the processed map points are visualized using Octomap. The implementation utilizes the services provided by the Robot Operating System (ROS). The powerful Rviz software on the ROS platform is used. The processed map points as cloud data are published in ROS and visualized using Octomap.

Simulation results confirm that Octomap can show the terrain details well in the 3D visualization of the environment. After the simulations, visualization experiments for two environments of different complexity are performed. The experimental results show that the approach can mitigate the influence of noise on the visualization results to a certain extent. It is shown that for static high-precision point clouds, Octomap provides a good visualization. The simulation and experimental results demonstrate the applicably of the approach to visualize 3D map points for the purpose of autonomous navigation.


Benhao Wang


Degree Type

  • Master of Science in Electrical and Computer Engineering


  • Electrical and Computer Engineering

Campus location

  • Hammond

Advisor/Supervisor/Committee Chair

Nasser Houshangi

Additional Committee Member 2

Dave Kozel

Additional Committee Member 3

Donald Gray