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PDE-Based Robust Robotic Navigation Computer Vision & Image Processing Laboratory (CVIP) University...
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PDE-Based Robust Robotic NavigationComputer Vision & Image Processing Laboratory (CVIP)
University of Louisville, Kentucky.Aly A. Farag, M. Sabry Hassouna, Alaa E. Abdel-Hakim, and Mike Miller
PDE-Based Robust Robotic NavigationComputer Vision & Image Processing Laboratory (CVIP)
University of Louisville, Kentucky.Aly A. Farag, M. Sabry Hassouna, Alaa E. Abdel-Hakim, and Mike Miller
AI RoboticsAI RoboticsAI robot is the one that possesses unsupervised intelligent performance in dynamic or unknown environments.
Sensor Suite• Stereo camerasStereo cameras• Pan-tilt units Pan-tilt units GPS.GPS.• Electronic Electronic Compass.Compass.• Inclinometer.Inclinometer.• Inertial Sensor.Inertial Sensor.• Laser Scanners.Laser Scanners.• SonarSonar.
Robotic Path PlanningRobotic Path PlanningIn robotic navigation, path planning is aimed at getting the optimum collision-free path between a starting and target locations.
The optimality criterion depends on the surrounding environment and running conditions.
In most of indoor navigation, the optimum path is the safe one, while for outdoor navigation, the shortest path is more recommended.
Global Vs. Local PlanningGlobal Vs. Local PlanningGlobal planning takes into account all the information in the environment when finding the optimum path. However, it is time consuming in the pre-computation step. (Cell decomposition-91, Voronoi-00, randomized sampling-02)
Local Planning avoids dynamic obstacles within a close vicinity of the robot. Potential field methods. (Latombe-86, Khatib-92) are the most popular ones, which are fast, but may converge to local minimum in dense environment.
iRobot - CVIP LabiRobot - CVIP Lab
IndoorIndoor OutdoorOutdoor
Min. Cost Path ProblemMin. Cost Path Problem
From geometrical optics, the solution From geometrical optics, the solution satisfies the satisfies the Eikonal equation
ObjectiveObjectiveDeveloping novel path planning technique that overcome the voids in the current approaches.
Integrating the current resources at University of Louisville and CVIP lab in mobile robots, simulation, and active vision, in order to develop a complete navigation platform that can be used in different missions for various environments.
This project is envisioned to be the first step in a potentially long-term collaboration with NASA in smart robotics R&D for space exploration, especially unmanned missions to outer space.
Medial Path Extraction TheoremMedial Path Extraction Theorem
The most stable method for solving this equation is the fast marching methods (FMM) (Sethian-95,-99).
Numerical errors along diagonals. Non-optimal computational complexity.
To overcome these limitations, we have developed a highly accurate numerical solution method, called the Multi-Stencils Fast Marching (MSFM), which combines multi-stencils with directional derivatives.
Medialness Function Medialness Function λλ(x)(x)Euclidean Distance FieldEuclidean Distance Field
Absolute Divergence FieldAbsolute Divergence Field
Optimum Path Extraction (OPE)Optimum Path Extraction (OPE)In the isotropic fast marching, the fastest traveling is always along the direction perpendicular to the wave front (Bellman-65). Therefore, the OPE can be extracted by backtracking along the steepest Descent by solving the following ODE.
Global Path PlanningGlobal Path PlanningExtract the desired path between A and B.
If dynamic objects are detected by robotic sensors, the map is updated and the path is re-planned.
For terrain environment, we assume that we have its height map.
For Shortest Path,
For Hybrid Path,
For Safe Path,
If the robot is doing a regular job. Then, it is efficient to store the entire safe paths of the map such that given any two locations A and B, we can quickly compute the safest path between them.
Local Path PlanningLocal Path Planning
Shortest Path Safe PathHybrid Path
Robot is represented by a white square.
Experimental ResultsExperimental ResultsMethodMethod Local Local
PlanningPlanningGlobal Global
PlanningPlanningSafe Safe PathPath
Shortest Shortest PathPath
Hybrid Hybrid PathPath
Local Local Min.Min.
Proposed Proposed MethodMethod
xx
Virtual Virtual ForcesForces
xx xx
Heurisitic Heurisitic Search Search
A*A*
xx xx xx xx
Voronoi Voronoi PlanningPlanning
xx xx xx xx
1. Entire Safe Paths for Global Planning
2. Global Path Planning
3. Safe Path Extraction from Different Source Points
4. Local Path Planning for Planar Environment
Shortest Path Safest Path
5. Local Path Planning for Terrain Environment
Terrain Environment Iso-Contours
Shortest and Minimum Energy Paths
Future WorkFuture Work
ReferencesReferences
Fully autonomous navigation of robots for commercial and DoD applications.
Perception-based navigation in unknown environments such as Mars to guide rovers like Spirit & Opportunity.
http://www.nasa.gov
1. M. Sabry Hassouna, A.A. Farag, and Alaa Abdel-Hakim, "PDE-Based Robust Robotic Navigation," Journal of Image and Vision Computing (IMAVIS), Under Review.
2. M. Sabry Hassouna and Aly. A. Farag, "Accurate Tracking of Monotonically Advancing Fronts," Parametric and Geometric Deformable Models: An application in Biomaterials and Medical Imagery, Jasjit S. Suri and Aly Farag, Editors, Springer, 2006. 3. M. Sabry Hassouna and Aly. A. Farag, "PDE-Based Three Dimensional Path Planning For Virtual Endoscopy," Parametric and Geometric Deformable Models: An application in Biomaterials and Medical Imagery, Jasjit S. Suri and Aly Farag, Editors, Volume 2, Springer, 2006 (in press).
4. M. Sabry Hassouna and A.A. Farag, "Accurate Tracking of Monotonically Advancing Fronts," Proc. of IEEE Conference on Computer Vision and Pattern Recognition (CVPR'06), New York, NY, USA June 17-22, 2006.
5. M. Sabry Hassouna and A.A. Farag, "Robust Centerline Extraction Framework Using Level Sets," Proc. of IEEE Conference on Computer Vision and Pattern Recognition (CVPR'05), San Diego, CA, USA June 20-26, 2005, pp. 458-465.
6. M. Sabry Hassouna, A.A. Farag, and Alaa E. Abdel-Hakim, "PDE-Based Robust Robotic Navigation," Proc. of Second Canadian Conference on Computer and Robot Vision (CRV'05), British Columbia, Canada, May 9-11, 2005, pp. 176- 183. Has been nominated to appear in a special issue of "Journal of Image and Vision Computing".