An Autonomous Wheelchair at an Art Gallery

 

Beurs van Berlage, Amsterdam, 16 December 2009 to 8 March 2010

Our robotic wheelchair has been exhibited at Niet Normaal in Amsterdam from December 2009 to March 2010. See a Youtube video or a local copy (WMV) (thanks to Aram Voermans for filming and editing).

 

Institute of International Visual Arts (INIVA),  London, 2008

The autonomous wheelchair "Psalms" commissioned by the late Donald Rodney in 1997 has been exhibited at the exhibition "Donald Rodney In Retrospect". Curated by Sebastian Lopez and Keith Piper. Produced by Iniva (Institute of International Visual Arts).

    

Psalms at INIVA Psalms at INIVA
Psalms and Britannia Hospital 3 (Installation view of Donald Rodney in Retrospect) Installation view of Donald Rodney in Retrospect Photograph © Thierry Bal, Courtesy of Iniva at Rivington Place

 

South London Gallery 1997

An autonomous wheelchair has become a piece of art named "Psalms" as a part of an exhibition entitled "Nine Night in Eldorado" by Donald Rodney, held at the South London Gallery until the 12th October 1997 (Fig 1,2,3 and wc1.mov).

"...Our fear of automata is again harnessed in Psalms, as the empty wheelchair courses through its various trajectories on a sad and lonely journey of life, a journey to nowhere. Its movements repeat like an ever recurring memory, a memory of another life and another journey, that of Donald Rodney's father..." (Exhibition brochure, Jane Bilton.)


Opening day
Opening day
Opening 
day
Fig.1. A part of the exhibition.
(click on the images to see
larger versions)
Fig.2. Waiting for a conversation to end before resuming its walk...
...or taking part ?
Fig.3. A lonely presence after the closure.


The wheelchair was modified at the School of Computing of the University of Plymouth to perform a repeated sequence of circles, spirals and figures of eight, as specified by the artist Donald Rodney, himself disabled by sickle cell anaemia.

The wheelchair uses 8 sonar sensors (fig.4) , shaft-encoders, a video camera and a rate gyroscope to determine its position. A neural network using normalised RBF nodes encodes the sequence of 25 semi-circular sequences of positions forming the trajectory (fig.5).

The control system comprises a laptop PC 586 running a control program written in CORTEX-PRO, and linked to a Rug Warrior board built around the 68000 microcontroller.


Wheelchair sonar 
sensors
Neural Network
Fig.4. Orientation of the sonar sensors. The sensors are mainly oriented in front for safety reasons. Sensors 1,3,5 and 8 are also used for self-localisation purpose when the wheelchair is oriented parallel to a wall. Fig.5. Neural network based on normalised RBF nodes encoding a sequence of sequences of positions (a figure of eight in this example). Layer L1 comprises input nodes representing the x,y position of the wheelchair. Layer L2 comprises usual RBF nodes centred on successive positions. Nodes in layer L3 perform the normalisation so that their ouputs represent positions in the same form as nodes in layer L1. More details on normalised RBF nets can be found in Althofer and Bugmann (1995), Bugmann (1996), Bugmann et al. (1998).


Contributors:

The control system of the wheelchair was built by: