Low Cost Tracking Of Commuter on Roads Dr. Naveen Aggarwal, Samriddhi Singla, Simran Jain
UIET, Panjab University
To detect public bus boarding and de-
boarding events using user’s
smartphone barometer sensor,
through which we can calculate
public bus occupancy.
Objective Methodology
• Correlation is applied to barometer values of 50 seconds of bus and
user’s smartphone, which constitute a window.
• The barometer readings are fetched at a frequency of 1 Hz.
• Correlation is applied to consecutive windows which are obtained by
sliding the windows by 10 seconds.
• Did not get high correlation value
for 50 second window when bus
is not moving (stuck) or moving at
very slow speed (congestion), even
if user is in bus.
• Reason for the same:
In stuck or congestion, barometer
readings don't change significantly
Random change in barometer
readings.
Challenges
Adapting the
System • Checked the
correlation only when
the bus is in moving
state (not in case of
congestion or stuck).
• Reduced the
computation by
checking correlation
values only upon
arrival or departure of
the bus from the bus
stops.
• Used the
accelerometer of user's
phone to detect the
state of motion.
Data Collection
• Data was collected in
Chandigarh using local CTU
(Chandigarh Transport
Undertaking) buses.
• Phones Used: Google Nexus
5, Google Nexus 5x and
Xioami MI4
• One phone was placed in bus
which acted as barometer of
bus, user boarded the bus
with two phones and then de-
boarded.
• Total journeys: 6
• Total hours: 4
xus 5: Acted as barometer of bus Nexus 5x and Mi4: Carried by user
Results
Boarding and De-boarding detection results:
Phones Max. Correlation
before boarding
Correlation
during
boarding
Min. Correlation
(user in bus)
Max. Correlation
after de-boarding
Nexus 5 &
Nexus 5x
0.721 0.928 -0.014 0.754
Nexus 5 &
MI4
0.737 0.955 -0.002 0.738
Nexus 5: Acted as barometer of bus; Nexus 5x and Mi4: Carried by user
5: Acted as barometer of bus Nexus 5x and Mi4: Carried by user
Conclusion The change of barometer readings of bus and user's phone can be compared using
correlation and can be used to detect boarding and de-boarding events, and hence .
to calculate the occupancy of a bus, by maintaining a passenger count.
De-boarding Module
Boarding Module
