Embedded Autonomous Wheelchair Navigation System for AAL Scenarios Author: Davide Ortenzi Università Politecnica delle Marche DII – Dipartimento di Ingegneria dell’informazione Co-authors: L. Cavanini, G. Cimini, A. Monteriù, A. Freddi and S. Longhi Lecco, 21 May 2015

Objective Development of a low cost localization system applied to Ambient Assisted Living applications, in particular to a power wheelchair. Key points: Low cost system Smart set up Fully automatized Reliable Lecco, 21 May 2015

Motivation: state of the art Part of the disable community finds difficult to use normal wheelchairs Several studies about smart wheelchairs since the early 1980s 9-10% of patients finds smart wheelchairs difficult to use 40% of patients finds maneuvering and steering tasks difficult to accomplish solutions closely related to a particular vehicle (hardware set-up problem) solutions characterized by an high cost (hardware cost problem) Lecco, 21 May 2015

System overview Sunrise Quickie Salsa R2 24V, 60 A battery proprietary closed communication protocol analog control joystick Software system Arduino Microcontroller Raspberry Pi2 Embedded board Robotic Operating System framework (ROS) Sensor system Inertial measurement system (IMU) Laser Scanner Rotative encoders Lecco, 21 May 2015

System overview: ROS based software Algorithms: Nodes Communication Channels: Topics Lecco, 21 May 2015

Methods Dead-reckoning problem Extended Kalman Filter (EKF) Iterative non-linear system model linearization with respect to the new working point Global Localization problem Adaptive Monte Carlo Localization Particle filter based robot position estimation with respect to static map and acquired laser scanner data Lecco, 21 May 2015

Results: Odometric localization (EKF) medium error = 0.5092% Lecco, 21 May 2015

Conclusion and future works Completed task Smart system setup Correct localization Cheap system Easy reconfigurable system Next development Introduction of cheap vision sensors (webcam) and testing of vision localization algorithms on embedded architecture Development of a smart GUI (Android based) for special user needs Lecco, 21 May 2015

Thank you for your attention! Questions Thank you for your attention! Lecco, 21 May 2015