1. 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

2. 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

3. 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

4. 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

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

6. 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

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

8. 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

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