SL869-3DR Evaluation Kit User Guide
1VV0301266 r0
2016-11-14
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Page 12 of 35
Mod. 0810 2011-07 Rev.2
2.2.
MEMS-only Dead Reckoning (MoDR) Description
The SL869-3DR module contains embedded sensors to eliminate the need for connections to
vehicle sensor systems. These sensors include:
•
3-axis accelerometers
•
3-axis gyros (angular rate sensors)
•
Barometric pressure sensor
The SL869-3DR is delivered with innovative Telit-developed MoDR firmware (FW) which
calculates the vehicle speed and attitude (in 3 dimensions) for inclusion in the navigation
solution.
Since the SL869-3DR does not require vehicle signals for speed or forward/reverse, installation is
much simpler and less costly than the classic DR configuration.
MoDR has the advantage of reducing installation time, complexity and cost, but does not achieve
the highest level of accuracy provided by vehicle sensors for wheel ticks and forward/reverse
signal for direction. Thus, there is a trade-off of cost vs. performance between the two system
designs.
Telit also has Classic DR products such as the SL869-ADR, which make use of vehicle sensor
input to achieve the highest level of accuracy, which is particularly attractive for original
installations.
