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