Abstract:
This paper introduces a low cost method of sensing
position using a optical sensor. Main objective of this study was
to overcome the shortcomings associated with the conventional
contact type of position sensors using a low cost device. In a
slippery terrain, rotary encoder based data often produce
erroneous results, whereas, if optical based method is used it
could be preferred. For this study, PAN 3101 type low cost
CMOS optical sensor is used. This sensor is often used for
making computer mice. Built device comprises of a PAN 3101
sensor, lens assembly, illuminating components and a
microcontroller based interface. Lens assembly comprises of the
convex lenses. PAN 3101 sensor processes the images that are
taken through the lens assembly and gives the position in terms
of relative distances traveled in vertical and horizontal
directions. Microcontroller based interface handles the
communication between PAN 3101 sensor and the main
application that utilizes this technology. So this module can be
used in applications that needs smooth position detection
capabilities. Built device was attached to a mobile robot so that
the robot can be driven from the position information of the
rotary encoder and the new optical position sensing device.
Results from both rotary encoder and optical device are
presented to validate the applicability of the proposed concept.
