3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.
-
date post
20-Dec-2015 -
Category
Documents
-
view
217 -
download
2
Transcript of 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.
![Page 1: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/1.jpg)
3D Mapping Robots
Intelligent Robotics
School of Computer Science
Jeremy Wyatt
James Walker
![Page 2: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/2.jpg)
What Are 3D Mapping Robots and Their Uses?
• Robots which produce a 3-dimensional model of their environment from the data they collect
• They can be used by people who need to know more about the interior of a building:
• Architects• Fire fighters• Human rescue workers
![Page 3: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/3.jpg)
Types of Sensing Techniques
• Stereo vision• Laser range finders• A combination of the two
![Page 4: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/4.jpg)
Stereo Vision
• Use stereo disparities to compute depth
• Inaccurate in detecting the position of walls and objects especially in cluttered environments
![Page 5: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/5.jpg)
Laser Range Finders
• Very accurate in measuring distances to walls and objects in the environment
• Has a range of 8m with a resolution of 1mm and a statistical error of +/-10mm
• Can not detect any texture in the environment so can only produce single coloured models
![Page 6: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/6.jpg)
A Combination of the Two
• Laser range finders for detecting the distance of walls and objects
• An omni-cam for producing texture maps for a realistic visualisation of the environment
![Page 7: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/7.jpg)
The GATech Robot
• Equipped with a laser range finder positioned vertically to scan perpendicular to the movement of the robot
![Page 8: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/8.jpg)
How the Robot Builds the 3D Models
• Collects raw data from the environment using the laser range finder
• Converts the raw data into Cartesian co-ordinates• Converts the Cartesian co-ordinates into a mesh
for the 3D model
![Page 9: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/9.jpg)
How the Robot Collects the Raw Data
• Laser moves through 180˚ in 0.5˚ steps from one side of the robot over the top to the other recording the distance
• Approximately 38 scans are completed every second
• Robot moves forward at 0.25m/s• Therefore approximately one scan every 5cm
![Page 10: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/10.jpg)
Transforming the Raw Data Into Co-ordinates
• Raw data is in the form of cylindrical co-ordinates• Transformed using the pose of the robot, the angle
of the scan and the height of the centre of the laser scanner
![Page 11: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/11.jpg)
Collecting the Co-ordinates to Form Triangles
• Choose two scan points p1 and p2 from the same scan, taken at angles α and α + 0.5˚
• Choose the two corresponding points q1 and q2 from the next scan
• Form two triangles p1p2q1 and q1p2q2
• For each triangle calculate its normal vector
![Page 12: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/12.jpg)
GATech Model
![Page 13: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/13.jpg)
GATech Model
![Page 14: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/14.jpg)
GATech Model
![Page 15: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/15.jpg)
Disadvantages of This Approach
• The corridor appears to be slightly curved due to the way the robot moves
• Obstacles below a height of 0.52m can not be detected by the robot
• No filtering techniques were used so the model is very noisy but retains a high level of complexity because of this
![Page 16: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/16.jpg)
Further Examples: Thrun et al
• Uses two laser range finders and an omni-cam
• Uses a technique called expectation maximisation
• Processes the data to reduce the noise
![Page 17: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/17.jpg)
Expectation Maximisation
• Estimates the number of surfaces and their location
• Adds and removes surfaces until it converges on the best fit model for the data
![Page 18: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/18.jpg)
Thrun et al
![Page 19: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/19.jpg)
Thrun et al
![Page 20: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/20.jpg)
Summary
• Brief overview of what 3D mapping is and some uses for 3D mapping
• Different types of sensors used• How to collect data and convert it into a 3D model• Some more advanced methods for 3D mapping
and processing of the data
![Page 21: 3D Mapping Robots Intelligent Robotics School of Computer Science Jeremy Wyatt James Walker.](https://reader030.fdocuments.in/reader030/viewer/2022032800/56649d445503460f94a215e9/html5/thumbnails/21.jpg)
References
• www.cc.gatech.edu/ai/robot-lab/research/3d/• www-2.cs.cmu.edu/~thrun/3d/