Bar coded retroreflective target

Patent · Sat Jan 01 04:00:00 EST 2000

OSTI ID:872825

Vann, Charles S ^[1]

---

1. Fremont, CA

This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• DOE Contract Number: W-7405-ENG-48
• Assignee: Regents of University of California (Oakland, CA)
• Patent Number(s): US 6017125
• OSTI ID: 872825
• Country of Publication: United States
• Language: English

Related Subjects

/359/235/250/
alternatively
angle
ball
bar
bar code
bar coded
beam
calculate
calculation
capable
causes
characteristics
code
coded
compact
degrees
detect
devices
dimensional
directed
directed towards
diverging
enabling
enters
expensive
field
fixed
fixed position
formed
heavy
illuminates
inexpensive
information
intensity
laser
laser beam
lens
light
light-weight
location
locations
measured
moves
non-contact
optically
plane
position
produces
provide
provide information
reflective target
relatively
relatively inexpensive
retroreflective
retroreflective target
retroreflector
retroreflectors
return
return beam
returns
scan
senses
sensor
simplicity
six
six degree
six degrees
space
swept
target
target position
three-dimensional
time
towards
tracker
tracking
unique
unique characteristic
unique characteristics
view
volume