An Optical Proximity Sensor for Measuring Surface Position and Orientation for Robot Manipulation
Original Publication Date: 1983-Sep-05
Included in the Prior Art Database: 2007-Mar-29
Software Patent Institute
Kanade, Takeo: AUTHOR [+3]
An Optical Proximity Sensor for Measuring Surface Position and 0
An Optical Proximity Sensor
for Measuring Surface Position and 0
rientatioi for Robot Manipulation
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rjfi6'ggg;8i;i; nd Thomas M. Sommer YAI ... E Lil'jiL'~RS,
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Robotics Institute Carnegie-Mellon University Pittsbu.rgh, Pennsylvania 15213
Copyright @ 1983 The Vision laboratory, Carnegie-Mellon Unive~
This research was supported by the Robotics Institute, Carnegie-Mellon University, an1 of Naval Research.
n par4 by the Office
We have developed a noncontact proximity sensor which can measure the distance and orie tation of a surface
in a range of four tofive centimeters. The sensor is based on the scheme of aclive illuminatio and triangulation.
It uses multiple infrared LEDs as the light sources and a PIN-diode area sensor chip for detecting the spot
positions. Six LEDs with opticsfor collimating the beam are mounted at zhe sensor head. e directions of the
beams are aligned to fonn a cone of light converging at a distance qf 4.5 cm fiom lhe sensor ead. As each LED
is sequentially pulsed the sensor chip detects the position, in its field of view, of the spot pr 'ected by the LED
light beam on the object su$ace. The 3-0 location of the spot on the surfce can be comput by iriangulation
By doing this for six LEDs we obtain a set of six 3-0 points. Then by fitting a plane io those
Since there is no moving part and the spot position sensor chip is an analog sensor which outputs the position
of rhe spol directly without scanning its field of view, we can realize fist operation of oub proximity sensor.
Currenlly the sensor can give approximately ZOO0 measurements of distance and
precision of 0.07 mm for distance and 1.9 for sugtace orientation. This non-contact sensor will be
useful for such applications as tracing an object surface by a robot arm with spec$ed
relative to the surface
and orientation of a small portion of the object surface are calculated
Recently considerable effort has gone into research on rangefinding sensors. The quan to be measured in range finding includes distance, surface orientation, surface curvature, and
such as reflectivity. Proximity sensors grew from the need to gain
proximity to the robotic device. They occupy a unique niche in the
sensing gap between the gross imaging of vision systems and the direct contact of tactile sknsors. The spatial measurement capability of the proximity sensor allows a representation to be cted of the local environment.
Many types of proximity sensors have been b...