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| − | ====Auto calibration before firmware version 03.25.07.Rev.00.====
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| − | Accelerometer auto calibration functionality has one purpose - determine how FMB device
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| − | is mounted in a vehicle. After the calibration process ''eco driving'' functionality becomes active
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| − | and calibration data will be used to determine harsh acceleration, braking and cornering events.<br />
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| − | There are two conditions when auto calibration takes place:<br />
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| − | *If on device startup no calibration was detected;
| + | ======Auto-calibration====== |
| − | *If the device receives an SMS/GPRS message with ''auto_calibrate:set'' text.<br />
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| − | | |
| − | After functionality has started FMB device periodically checks current appliance GNSS,
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| − | ignition and movement source parameters and if the conditions match:<br />
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| − | | |
| − | *position fix got;
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| − | *GNSS speed is zero;
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| − | *ignition is ON;
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| − | *first calibration vector was not saved yet;<br />
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| − | | |
| − | Then first vector is taken. Saved vector will be considered as ground vector and it will be
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| − | used at further calibration calculations.<br />
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| − | ''Note: When FMB device saves first ground vector vehicle must be parked on flat ground''.
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| − | Crooked vector may have an impact on further calculations.<br />
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| − | Afterwards first ground vector was taken, device analyses conditions:<br />
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| − | | |
| − | *position fix got;
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| − | *GNSS speed is at least 20 km/h;
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| − | *ignition is ON;
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| − | *second vector was not saved yet;
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| − | *vehicle driving in the same direction with 5⁰ tolerance;
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| − | *vehicle speed increase by 7km/h within 1 second.<br />
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| − | | |
| − | For next vector. Second vector will be taken if all conditions match. Immediately after
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| − | second vector is received, it will be multiplied by first (ground) vector, the result of these
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| − | vectors is vector multiplication cross product which is the right side of a car. By using
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| − | same vector multiplication method, device front, left side will be calculated. At this point
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| − | calibration is successfully ended as indication device sends an SMS/GPRS message with
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| − | ''Device is calibrated, to recalibrate send:auto_calibrate:set''.<br />
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| − | ''Note: SMS/GPRS message will be sent only if auto calibration functionality was triggered by''
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| − | SMS/GPRS message''.<br />''
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| − | For user convenience in case auto calibration functionality fails then notification message
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| − | will be sent. For exact messages, check algorithm section.<br />
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| − | ''Note: SMS/GPRS message will be sent only if auto calibration functionality was triggered by''
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| − | SMS/GPRS message''.<br />''
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| − | To get current calibration status ''auto_calibrate:get'' SMS/GPRS command must be sent to
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| − | the device. If device is calibrated it will respond with ''Calibration state: calibrated'' or otherwise
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| − | ''Calibration state: not calibrated''. Also this command returns saved Ground and Side vectors.<br />
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| − | After every TRIP START event, device starts shadow calibration. This type of calibration is
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| − | running in parallel with already saved vectors (this means that vectors does not reset until
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| − | shadow calibration have both new vectors). After shadow calibration is done, device updates the
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| − | vector values to the new ones. There are two conditions when shadow calibration does not run
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| − | at TRIP start event:<br />
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| − | | |
| − | *Normal calibration is still running.
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| − | *Shadow calibration is still running from previous TRIP event.<br />
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| − | | |
| − | To take ground vector these conditions should be met:<br />
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| − | | |
| − | *Ignition is ON
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| − | *Device got GPS FIX
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| − | *Vehicle speed = 0km/h<br />
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| − | | |
| − | Device will check these conditions every 1sec until they will pass.<br />
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| − | To take side vector these conditions should be met:<br />
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| − | | |
| − | *Vehicle speed >= 20km/h
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| − | *Device got GPS FIX
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| − | *Ignition is ON
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| − | *Device angle does not change more than 5 degrees in past 1 sec
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| − | *Speed need to increase by 7km/h in 1s period.<br />
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| − | | |
| − | Device will check these conditions every 1 sec until they will pass.<br />
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| − | | |
| − | | |
| − | ====Auto calibration rework and improvements from firmware version 03.25.07.Rev.00.==== | |
| − | | |
| − | 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.
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| − | | |
| − | Auto calibration task is launched on one of these conditions (assume calibration is enabled in configuration):
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| − | *Every time device turns on, it checks whether it was previously calibrated and has calibration stored in flash. If device has no calibration in flash, auto calibration task is started.
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| − | *Device calibration was previously disabled by configuration and now is enabled.
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| − | *SMS “auto_calibrate:set” is received. Note: SMS response is sent after calibration has been acquired.
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| − | This SMS triggers an SMS response to be sent. Response is sent when calibration is acquired. When 1 hour passes without successful calibration, failed SMS response is sent.
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| − | *Calibrated device’s mean axes of set interval differ more than set amount from desired (0,0,1) calibration is considered inaccurate. Calibration is deleted from flash and auto calibration task started.
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| − | After auto calibration task has been started, it will go on indefinitely until satisfactory calibration is acquired.<br />
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| − | | |
| − | =====Auto-calibration Improvement=====
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| | | | |
| | Auto calibration task is launched on one of these conditions (assume calibration is enabled in configuration):<br> | | Auto calibration task is launched on one of these conditions (assume calibration is enabled in configuration):<br> |
