Introduction

• Octomap Definition
  • Efficient probabilistic 3D spatial mapping algorithm using Octree, data structure
• what?
  • Octree
  • probabilistic
  • 3D Mappoint(Mapping)
• Data representation method in 3D space : Voxel
• Probabilistic data representation : Occupancy Grid Map
• Efficient 3D Map data representation : Octree

Data representation method in 3D space

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• 2D 공간의 한 점을 정의한 그래픽 정보 -> Pixel
• 3D 공간의 한 점을 정의한 그래픽 정보 -> Voxel

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• By using these voxels, it can save space from data.

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• In other words, Octomap is a method of expressing data in a three-dimensional space using the concept of Voxel.

probabilistic

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• The sensor that acquires the information of the object may acquire uncertain data.

• Let’s express the existence of the object by probabilistic modeling the uncertainty of these sensors!

  • Object exists. (Occupied, OCC)
  • Object does not exist. (Non-occupied, EMP)

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• There are various ways to create an Occupancy Grid Map. (Various modeling methods.)
• See the blog below for more information.
  • http://jinyongjeong.github.io/2017/02/21/lec10_Grid_map/
• As a way of expressing the existence of data in Octomap, Occupancy Estimation (the basis for creating an Occupancy Grid Map) is used.

Efficient 3D Map data representation : Octree

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Summary

• Octomap includes all three features described above.

1. The concept of Voxel is needed to represent the data that exists in the 3D space.

2. Octree data structure is adopted for efficient data representation.

3. Since uncertainty exists in the data acquired by the actual sensor, the existence of the object is judged using the occupancy estimation method.

Reference

SLAM KR