"Persistent navigation and mapping using a biologically inspired SLAM system." The. International Journal of Robotics Re
RatSLAM and Grid Cells An overview of work by Michael Milford and colleagues
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People David Prasser
Janet Wiles Michael Milford
Gordon Wyeth 2
Papers • Milford, Michael J., Gordon F. Wyeth, and David Prasser. "RatSLAM: a hippocampal model for simultaneous localization and mapping." Robotics and Automation, 2004. Proceedings. ICRA'04. 2004 IEEE International Conference on. Vol. 1. IEEE, 2004.
! • Milford, Michael, and Gordon Wyeth. "Persistent navigation and mapping using a biologically inspired SLAM system." The International Journal of Robotics Research 29.9 (2010): 1131-1153.
! • Milford, Michael J., Janet Wiles, and Gordon F. Wyeth. "Solving navigational uncertainty using grid cells on robots." PLoS computational biology 6.11 (2010): e1000995. 3
RatSLAM • Biologically inspired and wired for largescale, long-term autonomy
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RatSLAM • Biologically inspired and wired for largescale, long-term autonomy
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RatSLAM • Biologically inspired and wired for largescale, long-term autonomy
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RatSLAM • Biologically inspired and wired for largescale, long-term autonomy
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RatSLAM • Biologically inspired and wired for largescale, long-term autonomy
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RatSLAM • Biologically inspired and wired for largescale, long-term autonomy
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Process
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Pose Cells and View Cells
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Network Iteration Global pose update:
Visual weights:
Visual pose update:
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Re-use of cells
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Relationship to Rodent Memory
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Place Cells & Head Cells O'Keefe, John. "Place units in the hippocampus of the freely moving rat." Experimental neurology 51.1 (1976): 78-109.
Taube, Jeffrey S., Robert U. Muller, and James B. Ranck. "Head-direction cells recorded from the postsubiculum in freely moving rats. I. Description and quantitative analysis." The Journal of Neuroscience 10.2 (1990): 420-435. 15
Grid Cells
May-Britt & Edvard Moser
Hafting, Torkel, et al. "Microstructure of a spatial map in the entorhinal cortex." Nature 436.7052 (2005): 801-806. 16
Place Cells vs. Grid Cells
Place Cell
Grid Cell 17
Entorhinal Cortex
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Firing Patterns in RatSLAM cells
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“Grids are anchored to external cues”
Moser
Milford
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“Grids persist after cue removal”
Moser
Milford
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Disambiguation Experiments
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Disambiguation Experiments
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The Need for Conjunctive Cells
Place/Head Cells
Grid Cells
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RatSLAM for Long-Term Autonomy & Goal-Based Navigation
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Process
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The Experience Map
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Building Experiences Experience: Similarity score: Transition link: New experience: Map relaxation:* * Duckett, Tom, Stephen Marsland, and Jonathan Shapiro. "Fast, on-line learning of globally consistent maps." 28 Autonomous Robots 12.3 (2002): 287-300.
Pruning the Experience Map
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Experience Map Results
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Experience Map Results
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Architecture
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Place Recognition
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Global Navigation
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Local Navigation
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Long-Term Stability
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Long-Term Stability
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Long-Term Stability
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Weaknesses • “The weakness is that the system deals rather inefficiently with cyclic changes such as day–night time cycles.” • “We would not expect the experience map maintenance and navigation procedures to handle major changes to the topology or geometry of the environment; this capability would require additional maintenance methods” 39
