Accelerometer Calibration - Teltonika FMB001 User Manual

Green/Eco Driving
Duration
Data Output.
ECO driving/Green driving functionality generates events on three cases. If vehicles:
• Acceleration exceeds defined parameter value
• Deceleration (braking) exceeds defined value
• Cornering force exceeds defined value
Program continously monitors and process data from accelerometer than decides
whether harsh event is detected or not. If any of three cases are satisfied event is
generated. Record is saved and sent to server (FMB001 must be configured properly).
Event value is multiplied by 100 before sending/saving record to get more precision
when displaying data*.
*Example. If acceleration harsh event of 3.55 m/s2 detected. Record with value 3.55*100 = 355
will be saved ant sent to server.
1 m/s² = 0.101972 G; 1 G = 9.80665 m/s²

5.8.2 Accelerometer calibration:

Accelerometer auto calibration functionality has one purpose - determine how FMB device
is mounted in a vehicle. After the calibration process "eco driving" functionality becomes active
and calibration data will be used to determine harsh acceleration, braking and cornering events.
There are two conditions when auto calibration takes place:
• If on device startup no calibration was detected;
• If the device receives an SMS/GPRS message with "auto_calibrate:set" text.
After functionality has started FMB device periodically checks current appliance GNSS,
ignition and movement source parameters and if the conditions match:
• position fix got;
• GNSS speed is zero;
• ignition is ON;
• first calibration vector was not saved yet;
Then first vector is taken. Saved vector will be considered as ground vector and it will be
used at further calibration calculations.
Note: When FMB device saves first ground vector vehicle must be parked on flat ground.
Crooked vector may have an impact on further calculations.
Afterwards first ground vector was taken, device analyses conditions:
• position fix got;
• GNSS speed is at least 20 km/h;
• ignition is ON;
If enabled, additional record with Green/Eco Driving event duration
(ms) will be saved and sent to server.
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