Summary of Data Collection For period of 27 May 2011 to 25 August 2011 Daniel Leow...

Summary of Data Collection

For period of

27 May 2011 to 25 August 2011

Daniel Leow ([email protected])

ContentsIntroduction and scope

Data collection setup

Data summary by bus typeAnalysis and findings

Data summary by axesAnalysis and findings

Conclusion


Introduction and Scope


Introduction and scope• Data captured in this stage of the research is to

profile the bus motion for each bus type. The profiling of the motion is to determined whether there are differences in bus motion among the three types of the buses.

• Data captured are;

X axis – Lateral motion where negative indicate left motion; positive indicate right motion.

Y axis – Longitudinal motion where negative indicate braking/deceleration; positive indicate acceleration.

Z axis – Vertical motion where negative indicate down motion; positive indicate up motion.


Introduction and scope• The three types of buses in Malaysia

Single Deck Low Floor(Metropolitan bus)

Single Deck High Floor(Express bus)

Double Deck (Express bus)


Introduction and scopeData captured are;

X axis – Lateral motion where negative indicate left motion; positive indicate right motion.

Y axis – Longitudinal motion where negative indicate braking/deceleration; positive indicate acceleration.

Z axis – Vertical motion where negative indicate down motion; positive indicate up motion.


Data Collection Setup


Data Collection SetupBasic hardware and software setup

USB GPS receiver (SiRF Star III)

Macbook Laptop with built-inaccelerometer

Figure 1: Basic Setup


Data Collection Setup (cont.)

Position: Equipment mainly placed on a flat surface in the bus to ensure that the accelerometer sensors are directly in contact with the bus.

Figure 2: Equipment in the bus

Figure 3: Equipment in the bus



Calibration: accelerometer is calibrated to zero point of the raw output values from the sensors

Figure 4: SeisMaCalibrate



Data: Captured using SeisMac, raw data stored in CSV file format.

Figure 5: SeisMac


Data Summary


Summary of Data

collection by

sessions

Table 1: Data CollectionDaniel Leow ([email protected])

Data Summaryby Bus Type


Data Summary Double Deck – Graph 1 (lateral and longitudinal)


Data Summary Double Deck – Graph 2

(vertical and velocity)


Data AnalysisDouble Deck

As shown in Graph 1, the lateral force is significantly relative to longitudinal force. As you can see the low and the high spikes are very much at the same frequency.

In Graph 2, the vertical force are relative to the velocity of the vehicle. As you can see that there are higher spikes when the vehicle speed are higher


Data Summary Single Deck Low Floor – Graph 3

(lateral and longitudinal)


Data Summary Single Deck Low Floor – Graph 4



Data AnalysisSingle Deck Low Floor

As shown in Graph 3, the lateral force is not significantly relative to longitudinal force. The spikes in the longitudinal forces are fairly consistent mainly because there are frequent stops.

In Graph 4, the vertical force are relative to the velocity of the vehicle. As you can see that there are higher spikes when the vehicle speed are higher.


Data Summary Single Deck High Floor – Graph 5

(lateral and longitudinal)


Data Summary Single Deck High Floor – Graph 6



Data AnalysisSingle Deck High Floor

As shown in Graph 5, the lateral force is significantly relative to longitudinal force. The spikes in the longitudinal forces are fairly consistent mainly because there are frequent stops.

In Graph 6, the vertical force are relative to the velocity of the vehicle.


Data Summaryby Axis


Data SummaryLateral Force (X axis) – Graph 7


Data AnalysisLateral Force (X axis)

There are higher lateral force for Single Deck Low Floor bus compared to the other two types of the buses.

This would have been expected because the buses taking many turns in the metropolitan roads compared to the express bus usually travels on straight road.

Followed by the Single Deck High Floor bus and the Double Deck bus has the least lateral force motion.


Data SummaryLongitudinal Force (Y axis) – Graph 8


Data AnalysisLongitudinal Force (Y

axis)There are higher longitudinal force for Single

Deck Low Floor bus compared to the other two types of the buses.

This would have been expected because the buses have to take frequent stops in the metropolitan roads compared to the express bus usually stops once or twice in the entire journey.

Followed by the Single Deck High Floor bus and the Double Deck bus has the least lateral force motion.


Data SummaryVertical Force (Z axis) – Graph 9


Data AnalysisLongitudinal Force (Y

axis)Double Deck and Single Deck Low Floor bus

shows fairly consistent readings.

Single Deck High Floor bus shows inconsistent in data reading mainly because the sensor also picks up the vibration from the bus engine.


Conclusion


Conclusion The lateral and longitudinal force are significantly relative to

each other especially for Double Deck and Single Deck High Floor bus. However, this is not much significant for Single Deck Low Floor bus.

Nevertheless, Single Deck Low Floor bus showed higher readings for both lateral (Graph 7) and longitudinal (Graph 8) force. For lateral force, it reached 0.6g. The other two types of buses only reached 0.4g.

As for the vertical force, it is significantly relative to velocity especially for Double Deck and Single Deck High Floor bus. However, this is not much significant for Single Deck Low Floor bus.

As such, the setting of equipment for driver notification alert can be determined from this findings.


Summary of Data Collection For period of 27 May 2011 to 25 August 2011 Daniel Leow...

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