Revision as of 21:35, 20 May 2010

LURCH - the autonomous wheelchair
Short Description:	augmenting commercial electric wheelchairs with autonomous navigation and obstacle avoidance
Coordinator:	MatteoMatteucci (matteo.matteucci@polimi.it)
Tutor:	SimoneCeriani (ceriani@elet.polimi.it), DavideMigliore (d.migliore@evidence.eu.com)
Collaborator:	GiulioFontana (giulio.fontana@polimi.it)
Students:	MatteoRossi (), MauroBrenna ()
Research Area:	Robotics
Research Topic:	Robot development
Start:	2007/02/01
End:	2010/12/31
Status:	Active

L.U.R.C.H. is the acronym of "Let Unleashed Robots Crawl the House".

LURCH is an extended version of an commercial electric wheelchair (Rabbit by OttoBock) equipped with:

1. An interface circuit for digital drive via a radio serial link (XBee modules)
2. Two on-board computers (PCBricks), powered by wheelchair batteries
3. A 7-inch touchscreen monitor (Xenarc 700TSV), 800x480 resolution (16:10 AR)
4. Two laser scanners Hokuyo URG 04LX
5. A colour camera FireI400 (resolution 640×480)
6. An odometry system based on encoders applied to the rear wheels

Main goals of the LURCH project are:

1. Add sensors and robotic functionalities to the powered wheelchair.
2. Add various command interfaces, such as Joypad wireless, speech command, brain-computer interface.
3. Semi-autonomous navigation with collision and obstacle avoidance.
4. Autonomous navigation by path planning and localization.

Functions currently provided by LURCH:

1. Driving by the original joystick or a Logitech RumblePad2 wireless joypad.
2. Obstacle sensing using planar scanner lasers.
3. Basic collision and obstacle avoidance behaviours.
4. Indoor localization by a fiducial marker system
5. Path planning and basic autonomous navigation.
6. Brain-computer interface driving system

Media Coverage

Lurch project appeared in many national and international media. You can see the related articles and videos in the MediaCoverage page.

Available Documentation

- Documentation on the interface circuit between the wheelchair joystick and computer: Media:LurchCircuitDocument.pdf.

- WARNING: the circuit was modified and the documentation above is upgraded by this new file: Media:LurchXBee.pdf.

- How to modify the wheelchair joystick to connect to the interface circuit: Media:LurchCircuitJoystick.pdf.

- Brief discussion about the interface circuit between the wheelchair joystick and computer: Media:LurchCircuitJoystickBrief.pdf.

- Brief description of the LURCH project: Media:LurchBriefDesc.pdf.

- Brief description of the communication between the wheelchair interface circuit and a PC via RS232 port: Media:LurchProtocol.pdf.

- Source code for PIC 18F452 microprocessor and Eagle project (schematic and board): Media:LurchCircuitProject.zip.

- Battery replacement done on May 2009, description of work: Media:LurchBatteryReplacement.pdf.

- Thesis by Simone Ceriani, titled Sviluppo di una carrozzina autonoma d'ausilio ai disabili motori (Development of an autonomous wheelchair to help motor-disabled persons): Media:LurchThesisCeriani.pdf (in Italian)

- Thesis presentation by Simone Ceriani (note: Videos don't work, you can found similar videos below): Media:LurchPresentazioneThesisCeriani.zip

- Thesis by Marco Dalli, titled Sviluppo di un sistema di controllo basato su odometria per una carrozzina robotica (Development of a control system based on odometry for a robotic wheelchair): Media:LurchThesisDalli.pdf (in Italian)

- Thesis presentation by Marco Dalli: Media:LurchPresentazioneThesisDalli.zip

- Thesis by Marco Assini, titled Sviluppo di un pianificatore di percorsi geometrici per una carrozzina autonoma (Development of a geometric path planner for an autonomous wheelchair): Media:LurchThesisAssini.pdf (in Italian)

- Thesis presentation by Marco Assini (the file contains a ppt version, a pptx, and a simplified pdf version without animation): Media:LurchPresentazioneThesisAssini.zip

- Thesis by Mauro Brenna, titled Scan Matching, Covariance Estimation and SLAM: Models and Solution for the scanSLAM Algorithm: Media:MauroBrennaMastersThesis2010.pdf‎ (in English)

- Pdf with ArtoolKitPlus Fiducial Markers collection. Dimension are 160x160mm. Media:ArtoolKitPlusMarkers-160mm.pdf.zip

PCBricks Configuration

PCBrick-03 and PCBrick-05 feature Xubuntu Linux 7.10, Xfce Window Manager, Openchrome graphics drivers and eGalax touchscreen drivers v1.08.1227 (Drivers here). The touchscreen is configured and calibrated on both machines, hence it can be used with either one or the other indifferently.

Electronics development

We are currently designing a new electronic main board for the wheelchair.

The idea is to base the whole system on a CANbus, allowing a complete modularization of the on-board electronics.

Read more on this topics here...

Software development

• Try a different sw architecture, now we are examinating orocos [1]
• Integrate Marco Assini's thesis (RRT planning) with current release
• Develop an improved navigation system Read more on this topics here...

LURCH YouTube Videos

• External link

• External link

• External link

• External link

• External link

People Involved

Andrea Bonarini

Matteo Matteucci

Davide Migliore

Giulio Fontana

Bernardo Dal Seno

Marco Dalli (ex-Tesista)

Simone Ceriani (Assegnista di ricerca)

Matteo Rossi (Tesista)

Marco Assini (ex-Tesista)

Mauro Brenna (Tesista)

Laboratory work and risk analysis

Laboratory work for this project is mainly performed at AIRLab/Lambrate. It includes some mechanical work and electrical and electronic activity. Potentially risky activities are the following:

• Use of mechanical tools. Standard safety measures described in Safety norms will be followed.
• Use of soldering iron. Standard safety measures described in Safety norms will be followed.
• Transportation of heavy loads (e.g. robots). Standard safety measures described in Safety norms will be followed.
• Robot testing. Standard safety measures described in Safety norms will be followed.