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Online Path Planning for Autonomous Underwater Vehicles in Unknown - - PowerPoint PPT Presentation
Online Path Planning for Autonomous Underwater Vehicles in Unknown - - PowerPoint PPT Presentation
Online Path Planning for Autonomous Underwater Vehicles in Unknown Environments Juan David Hernandez, Eduard Vidal, Guillem Vallicrosa, Enric Galceran, and Marc Carreras ICRA 2015 Presented by Youngki Kwon Contents Introduction Main
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Contents
- Introduction
- Main contribution
- Background
- Anytime path planning
- Lazy collision evaluation
- Octree-based map
- Main approach
- Framework
- Motion planning
- Experiment and result
- Summary
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INTRODUCTION
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Introduction
- AUVs must operate in unknown, cluttered and
dynamic environments
- AUVs are more exposed to collisions
- Drift effects on the position estimated by navigation
system
- Online capabilities of path planner make AUVs
- vercome global position inaccuracy
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MAIN CONTRIBUTION
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Main Contribution
- Combination of ideas from lazy collision
evaluation and anytime path planning algorithm
- For online path planning
- incrementally built octree-based representation of the
environment
- The experimental evaluation of the resulting
planning framework using the SPARUS-II AUV in a real-world setting
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BACKGROUND
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- Overall approach
- Quickly find a solution that is feasible, but not
necessarily optimal
- Exploit execution time to incrementally improve
towards optimal solution
- Desired properties
- Form of completeness guarantees
- Asymptotic optimality given more computation time
Anytime Path Planning
Anytime RRT* - Matthew Walter’s slide
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Lazy Collision Evaluation
- Only check for collisions when we have to
Check the collision after building the roadmap
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Octree-based Map
Techniques for 3d mapping - Wolfram burgard’s slide
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Octree-based Map
- Octomap
Techniques for 3d mapping - Wolfram burgard’s slide
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MAIN APPROACH
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Framework
- To solve start-to-goal queries for an AUV in an
unknown environment
- Framework for path planning online for AUVs
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Anytime Approach
- Under the time constraint, current T is left image
- Assume T is valid
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖
Time limit
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Anytime Approach
- Traverse T, check the collision, cut the subtree in collision
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖
Lazy Collision Evaluation
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Anytime Approach
- Sample configuration
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖
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Anytime Approach
- Extension in RRT*
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖
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Anytime Approach
- Extension in RRT*
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖
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Anytime Approach
- Extension in RRT*
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖
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Anytime Approach
- Extension in RRT*
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖
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Anytime Approach
- Extension in RRT*
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖
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Anytime Approach
- Find solution
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖
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Anytime Approach
- After Satisfying stop condition
𝒓𝒉𝒑𝒃𝒎 𝑺𝒑𝒑𝒖 𝑺𝒑𝒑𝒖
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EXPERIMENT & RESULT
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Experiment & Result
- AUV use
- Pressure sensor, Doppler velocity log, IMU
measurement, GPS
- Five Echosounders
- Experiments in both simulation and real world
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Experiment & Result
- Experiment in simulation
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Experiment & Result
- Experiment in real-world
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SUMMARY
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Summary
- Online capabilities of path planner make AUVs
- vercome global position inaccuracy
- Combination of ideas from lazy collision
evaluation and anytime path planning algorithm
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