Jostle mode tracking relies on the accelerometer sensing movement to start a trip. It's available as an option on the Remora/Remora2, Oyster/Oyster2 and Falcon.

The Yabby GPS and Wi-Fi is always in Jostle Mode as it is the only mode for these devices.


Jostle mode is useful for tracking small trips, or for tracking run hours for stationary devices that vibrate when they are in use, such as a pump.


To help you can choose an appropriate tracking mode, an overview of each mode's operation is provided below.


'Standard' GPS Tracking Mode – The normal mode that tracks trips well


  • Accelerometer wakes unit, or unit wakes on timer every few minutes if it is tired of being woken up all the time
  • On each wake, it gets a GPS fix
  • It tries to figure out if it is in trip by looking at the fixes
  • Once it thinks it’s moving, it enters a trip
    • Once in-trip, the accelerometer is turned off
    • It wakes up every few minutes on a timer and gets a fix
    • It checks if the trip is still in progress by looking at the fix
    • When the fixes suggest movement has stopped, it exits the trip 
    • (if the device can't get a fix for a while, it also exits the trip)
  • Uploading can happen before, during, and after the trip, optionally
  • Heartbeats happen if there has been no upload for a long time

 

Jostle Based Tracking – For special requirements (run-hours, tracking small trips)


  • Accelerometer wakes unit
  • Unit immediately enters trip
    • Once in trip, the accelerometer no longer wakes the unit
    • It wakes every two minutes on a timer, and does two things
      • Asks the accelerometer if there was any movement in the last two minutes
      • If it is time to log a position, it gets a fix and records it
      • Once the accelerometer claims there has been no movement for a while, and the GPS doesn't show movement, the trip ends
      • The trip can continue even if the GPS isn't showing movement, so long as the accelerometer is 
    • Uploading can happen before, during, and after the trip, optionally
    • Heartbeats happen if there has been no upload for a long time
    • The purpose of this is to allow trips to be recognized regardless of the size of the motion
    • It is much less robust than GPS tracking mode at rejecting false trips – so only useful for things like run hours, or tracking tiny trips

 

Jostle Uploads – For locating an asset after small movements in a yard


  • Jostle Uploads is an extra option for GPS Tracking Mode
  • GPS Tracking Mode will take care of locating the asset in-trip, but normally doesn’t provide any small-movement updates once the trip ends. So if you drive your car to work, it tells you it’s at work. But when you move it to a parallel street once your parking expires, it normally doesn’t update.
  • Jostle Uploads schedules a heartbeat after any small motions are detected out-of-trip.
  • The heartbeat updates the live view, showing that your car has moved to the parallel street, even though that small movement didn’t constitute a trip.



To configure an Oyster2 or Remora2 to use Jostle Based Tracking, set Jostle Based Tracking = Yes in the Advanced Tracking tab of the Edit System Parameters dialog on OEM server.

To configure an Oyster2 or Remora2 to use Jostle Uploads, set Upload On Jostle = Yes in the Advanced Tracking tab of the Edit System Parameters dialog on OEM server.


Device-specific articles and instructions can be found under the relevant folder in this knowledgebase.


Accelerometer Wakeup Settings + System Parameters

In order to detect trip starts reliably, the accelerometer is configured to be highly sensitive, waking up on the slightest jostle. In regular GPS trip tracking mode, the device then checks for a legitimate trip start using the GPS. Two mechanisms are available to prevent small vibrations during asset handling from causing an excessive number of nuisance wake-ups, for instance during the loading of a trailer. 


  1. After each wake up, the device sleeps for a short, fixed, time. This limits the maximum rate of wake-ups, and gives the asset an opportunity to get underway if it really is beginning a trip. In this case, the first GPS fix will be more likely to detect movement. 
  2. If too many jostle event are detected without any real movement being detected, the device will temporarily ignore the accelerometer, and sleep for a longer time before checking the GPS for movement. This provides a stricter limit on the maximum rate of wake ups. 




  • The Wake-up Delay is the minimum time spent sleeping after jostling has woken the Device. It can be set to zero if low latency is required, but in most cases is best set between 10 and 60 seconds, to give the asset a chance to start moving before the GPS is activated. 
  • The No Movement Limit is the maximum number of nuisance wake-ups to tolerate before switching to a longer sleep time. Each time the device wakes up, sleeps the Wake-up Delay, and then finds no GPS movement, it increments a counter. When the counter reaches the No Movement Limit, the device starts to sleep the No Movement Sleep Time between GPS checks. It continues this for as long as the jostle continues and no GPS movement is detected. 
  • The Jostle Upload Delay and Maximum Jostle Upload Delay are the timing parameters relevant to the Advanced Tracking -> Upload On Jostle option. 
  • The Jostle Upload Delay is the number of seconds to wait after a jostle before scheduling an upload. 
  • The Maximum Jostle Upload Delay prevents the upload being rescheduled (delayed) indefinitely during continuous jostling by forcing it to take place within a specified number of seconds after the jostling begins.
  •  The Jostle Upload Threshold optionally limits these uploads to those that show appreciable movement.