Place Entry / Exit Time Computation

There are 4 pings which are important for entry / exit time calculation of a place.
These are:

• P1 : Last ping before the place geofence

• P2 : First ping inside the place geofence

• P3 : Last ping inside the place geofence

• P4 : First ping outside the place geofence

Algorithm

The entry / exit time is calculated using the following algorithm:

• Given the place has a circular geofence G with a given radius

• Find the line L connecting P1 and P2 (for entry time) or P3 and P4 (for exit time).

• Find the intersection I of L with the geofence G

• Find the speed S of the truck along the line L.

• Find the time T when the truck would have reached the point I given it started at P1/P3 with speed S

• The time T is the entry / exit time.

Validity of Entry / Exit Time

Entry / Exit time computation based on the above algorithm is considered valid only if the time between P1 and P2 or P3 and P4 is less than a configurable parameter (Default value is 4 hours).

Place TAT Calculation

Place TAT is calculated as the duration between a valid entry and valid exit time.
If the entry / exit time is not valid, TAT will not be computed.

Tracking Status

Internal Trip States

• UNKNOWN (No Pings)

• BEFORE ORIGIN (Before detecting origin entry)

• AT ORIGIN (If last ping is inside origin geofence)

• IN TRANSIT UNSURE (Last ping is outside origin geofence, and origin exit was detected)

• IN TRANSIT SURE (Last ping is outside origin geofence, and origin exit was detected, additionally minimum duration of time elapsing)

• AT DESTINATION (Last ping is at destination, destination entry doesn't need to be detected)

• AFTER DESTINATION (Last ping is outside destination geofence, we have detected destination exit)

Last Mile Detection

If last ping is within LAST MILE RADIUS of destination then we are in last mile.

Note: LAST MILE RADIUS is independent of the destination geofence.