1 / 18

Part II Chapter 9: Topological Path Planning

Part II Chapter 9: Topological Path Planning. Objectives. Define the difference between natural and artificial landmarks; give one example of each

terryjonathan
Download Presentation

Part II Chapter 9: Topological Path Planning

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Part II Chapter 9:Topological Path Planning Chapter 9: Topological Path Planning

  2. Objectives • Define the difference between natural and artificial landmarks; give one example of each • Given a description of an indoor office environment and a set of behaviors, build a relational graph representation labeling the distinctive places and local control strategies for gateways • Describe in one or two sentences: gateway, image signature, visual homing, viewframe, orientation region • Given a figure showing landmarks, create a topological map showing landmarks, landmark pair boundaries, and orientation regions Chapter 9: Topological Path Planning

  3. Behaviors Behaviors Behaviors Behaviors Navigation • Where am I going? Mission planning • What’s the best way there? Path planning • Where have I been? Map making • Where am I? Localization Carto- grapher Mission Planner deliberative How am I going to get there? reactive Chapter 9: Topological Path Planning

  4. Spatial Memory • What’s the Best Way There? depends on the representation of the world • A robot’s world representation and how it is maintained over time is its spatial memory • Attention • Reasoning • Path planning • Information collection • Two forms • Route (or qualitative) • Layout (or metric) • Layout leads to Route, but not the other way Chapter 9: Topological Path Planning

  5. Route, or Qualitative Navigation Two categories Relational spatial memory is a relational graph, also known as a topological map use graph theory to plan paths Associative spatial memory is a series of remembered viewpoints, where each viewpoint is labeled with a location good for retracing steps

  6. Topological Maps Use Landmarks • A landmark is one or more perceptually distinctive features of interest on an object or locale of interest • Natural landmark: configuration of existing features that wasn’t put in the environment to aid with the robot’s navigation (ex. gas station on the corner) • Artificial landmark: set of features added to the environment to support navigation (ex. highway sign) • Roboticists avoid artificial landmarks! Chapter 9: Topological Path Planning

  7. Example Landmarks Chapter 9: Topological Path Planning

  8. floor plan Gateway is an opportunity to change path heading relational graph Relational Methods Nodes: landmarks, gateways, goal locations Edges: navigable path

  9. Kuipers and Byun: Spatial Hierarchy Chapter 9: Topological Path Planning

  10. Distinctive Place Approach Local control strategies (behaviors to get robot between DPs) Distinctive Places (recognizable, & at least locally unique) Chapter 9: Topological Path Planning

  11. neighborhood boundary distinctive place (within the corner) path of robot as it moves into neighborhood and to the distinctive place Actually Getting to a Distinctive Place: Neighborhoods Use one behavior until sees the DP (exteroceptive cueing) then swap to a landmark localization behavior

  12. de3 r1 r2 fh mtd mtd Room 1 Room 2 t1 fh t2 fh t3 fh de1 mtd mtd fh r4 r3 Room 3 Room 4 de2 Class Exercise • Create a relational graph for this floorplan • Label each edge with the appropriate LCS: mtd, fh • Label each node with the type of gateway: de, t, r Chapter 9: Topological Path Planning

  13. Associative Methods • Visual Homing • bees navigate to their hive by a series of image signatures which are locally distinctive (neighborhood) • QualNav • the world can be divided into orientation regions (neighborhoods) based on perceptual events caused by landmark pair boundaries • Assumes perceptual stability, perceptual distinguishability Randal Nelson, URochester Daryl Lawton, Advanced Decision Systems Chapter 9: Topological Path Planning

  14. Image Signatures Tesselated (like faceted-eyes) The world Resulting signature for home Chapter 9: Topological Path Planning

  15. Move to match the template Chapter 9: Topological Path Planning

  16. OR2 OR1 Topological Representation as Orientation Regions mountain Metric Map building radio tower tree

  17. Summary • Route, qualitative, and topological navigation all refer to navigating by detecting and responding to landmarks. • Landmarks may be natural or artificial; roboticists prefer natural but may have to use artificial to compensate for robot sensors • There are two type of qualitative navigation: relational and associative Chapter 9: Topological Path Planning

  18. Summary (cont.) • Relational methods use graphs (good for planning) and landmarks • The best known relational method is distinctive places • Distinctive places are often gateways • Local control strategies are behaviors • Associative methods remember places as image signature or a viewframe extracted from a signature • can’t really plan a path, just retrace it • direct stimulus-response coupling by matching signature to current perception Chapter 9: Topological Path Planning

More Related