Download Major Accomplishments FY1

Display of Stability Data for Safe Tractor Operation
D.J. Murphy and H.J. Sommer
Major Accomplishment FY1.1 - Five different dual-axis commercial sensors were evaluated including
two capacitive fluid tilt sensors, two micro-machined accelerometers and one MEMS accelerometer. The
MEMS device was selected based on cost ($10), sensitivity (10mG), direct digital (versus analog) output
and thermal zero shift that can be easily compensated.
Major Accomplishment FY1.2 - Four different microcontrollers were evaluated and tested in
combination with the sensors described above. The Atmel AVR 8-bit CPU was selected based on cost
($5) and ease of use.
Major Accomplishment FY1.3 - The AVR microprocessor and MEMS accelerometer combination were
validated on August 20 and August 22 during side and rear overturn tests at the PSU Larson Agricultural
Research Center using a new full size radio controlled tractor as shown in Figure 1. Images and videos
are available at http://www.me.psu.edu/sommer/projects/tractor/ .
Figure 1 - Side Overturn Test with New Full Size Radio Control Tractor
Major Accomplishment FY1.4 - The first onboard stability display consisting of an array of colored
LEDs was interfaced to the AVR/MEMS sensor package and carried on the radio controlled tractor
during side overturn tests reported above. An onboard video camera recorded the stability display during
tractor operation on a dangerous side slope. The display may be seen on the dashboard of the tractor in
the MPEG video http://www.me.psu.edu/sommer/projects/tractor/videos/side_onb1.mpg and at the URL
cited above.
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