Title
A Pencil Balancing Robot using a Pair of AER Dynamic Vision Sensors.
Abstract
Balancing a normal pencil on its tip requires rapid feedback control with latencies on the order of milliseconds. This demonstration shows how a pair of spike-based silicon retina dynamic vision sensors (DVS) is used to provide fast visual feedback for controlling an actuated table to balance an ordinary pencil. Two DVSs view the pencil from right angles. Movements of the pencil cause spike address-events (AEs) to be emitted from the DVSs. These AEs are transmitted to a PC over USB interfaces and are processed procedurally in real time. The PC updates its estimate of the pencil's location and angle in 3d space upon each incoming AE, applying a novel tracking method based on spike-driven fitting to a model of the vertical shape of the pencil. A PD-controller adjusts X-V-position and velocity of the table to maintain the pencil balanced upright. The controller also minimizes the deviation of the pencil's base from the center of the table. The actuated table is built using ordinary highspeed hobby servos which have been modified to obtain feedback from linear position encoders via a microcontroller. Our system can balance any small, thin object such as a pencil, pen, chop-stick, or rod for many minutes. Balancing is only possible when incoming AEs are processed as they arrive from the sensors, typically at intervals below millisecond ranges. Controlling at normal image sensor sample rates (e.g. 60 Hz) results in too long latencies for a stable control loop.
Year
DOI
Venue
2009
10.1109/ISCAS.2009.5117867
ISCAS
Keywords
Field
DocType
PD control,feedback,image sensors,microcontrollers,robot vision,robots,stability,AER dynamic vision sensors,PC updates,USB interfaces,microcontroller,normal image sensor sample rates,pencil balancing robot,rapid feedback control,spike address-events,visual feedback
Computer vision,Control theory,Image sensor,Computer science,Control theory,Pencil (mathematics),Microcontroller,Servomechanism,Artificial intelligence,Control system,USB,Servomotor
Conference
Citations 
PageRank 
References 
39
3.74
1
Authors
6
Name
Order
Citations
PageRank
Jörg Conradt138340.40
Matthew Cook210010.77
Raphael Berner324617.20
Patrick Lichtsteiner452047.13
Rodney J. Douglas5593242.90
Tobi Delbrück687682.59