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University of Kent School of Engineering and Digital Arts. Smooth Path Planning and Localisation. Michael Gillham University of Kent SYSIASS Meeting ISEN Lille 24.06.11. Current assisted wheelchair navigation technologies. Simple collision avoidance using proximity sensors
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University of Kent School of Engineering and Digital Arts Smooth Path Planning and Localisation Michael Gillham University of Kent SYSIASS Meeting ISEN Lille 24.06.11
Current assisted wheelchair navigation technologies • Simple collision avoidance using proximity sensors • Traction control for unknown surfaces • Course smoothing using gyro and compass
Future technologies • Complex dynamic and static real time hazard detection, collision and avoidance • Assisted waypoint/door traversing • Course/trajectory smoothing improvements • Path planning for autonomous navigation • Course/trajectory optimization
Potential fields • Fast real time processing • Simple representation • Well understood • Obstacle repulsion • Target or goal attraction
Potential field problems Localisation Local Minima Smoothness
Localisation Occupancy grid based mapping offers the possibility of localisation through room classification, both locally within that room and globally on higher level mapping. Fusing other sensor data improves the certainty.
Smoothness Smaller tick mark period = 10 cm Larger tick mark period = 100 cm Green dots are obstacles. Blue dot is the target. Agent starts in upper right corner with heading = 0 degrees (facing +x axis) White path is traversed with potential field method. Cyan path is traversed with human model. “Comparison of the Human Model and Potential Field Method for Navigation” SelimTemizertemizer@ai.mit.edu
Weightless Neural Networks • Pattern recognition from one shot learning • Network performs simple operations avoiding inefficient floating point arithmetic • Fast real time processing • No null output
Pattern recognition Right corner Corridor Classes Class certainty improved through data fusion techniques Local minima
Manipulating potential fields Local minima
Smoothness solution One problem is the angle of approach to waypoints such as corners and doors. The solution is to use WNN pattern recognition to determine the class of waypoint and use pre-determined potential fields to manipulate the trajectory.
Localisation solution Localisation obtained from fused sensor data for room occupancy pattern recognition and way point pattern recognition using layered WNNs. ADABOOST BASED DOOR DETECTION FOR MOBILE ROBOTS Jens Hensler, Michael Blaich, Oliver Bittel
Path planning solution Waypoints and goals can be mapped as a digraph, look up tables are used for classification and spanning tree patterns generated
University of Kent School of Engineering and Digital Arts Thank you. Any Questions?