www.gtri.gatech.edu

Wayne Daley, Principal Research Engineer, 404-407-8828, wayne.daley@gtri,gatech.edu

GTRI Aerospace, Transportation, & Advanced Systems Lab

Smartphone Sensing in Support of Maintenance and Planning ; Georgia Department of Transportation (GDOT) Research Project RP 10-27

Approach Phone Sensing – Estimated Parameters

IRI- Road Rougness

PACES – Pavement condition

Cross slope, pitch/roll, super elevation

Acceleration profiles

Radius of curvature

Passing Zone

Installation in Vehicle

Need to be simple

Mounting effects have to considered

Operational Tests

GDOT “Rodeo”

Chosen sites with varying conditions

For Further Information Contact

Project Objective

Assess the potential for the use of mobile devices to collect data to

support design, planning and maintenance activities.

Problem

Roadway condition monitoring necessary for a variety of needs

Assure that construction meets specifications

Data to support the planning and prioritization of maintenance operations

Improve efficiency and safety in the data acquisition process

Experimental Approach Results

System in Vehicle IMU and Phone User Interface

• Collected data at several reference sites and GDOT “Rodeo” • Demonstrates correlation with IRI and PACES pavement condition

assessment • Whole Body Vibration (WBV) could be a more intuitive and

utilitarian measure • Other useful data could also be utilized such as: • Acceleration profiles • Ability to determine passing zones • Possibility to crowd source data • Phone sensor suite could cost effectively impact GDOT data

acquisition, analysis and decision making.

Position Accuracy

Smartphone

Server data storage •Online access •Sensor data storage •Calibration data for vehicles/phones

Phone background service – Records sensor data •Timestamp •GPS •3-axis accelerometer •3-axis compass •Camera images Phone Storage/Upload

•Store data locally •Upload when possible •Handle data locally (delete/archive)

Phone UI app – Control acquisition, view data, local analysis •Status/control •Mapping points •Display values/plots •Annotate data (images/text)

PC PC Analysis app – View and analyze data offline •Map data points •Playback •Plotting

Research laptop Calibrated road assessment sensor 1

Calibrated road assessment sensor 2

PC Calibration Data app – Handle calibrated sensor data •Filter sensor data •Store locally •Upload to server

Z Axis Effect of Mounting X Axis Effect of Mounting

Sample Data US 78

Test Site Newton County, Route 122

PACES rating Average IRI rating

Jasper County, Route 16 89 763.5

Newton County, Route 212 73 980.5

Jasper County, Route 212 60 1082.1

Table 1 PACES/IRI ratings at sample sites

Test Sites with Varying Conditions

0

10

20

30

40

50

60

70

80

90

100

0 0.5 1 1.5 2

PACES comparison

Xsens

Phone-hard

Phone-velcro

0

200

400

600

800

1000

1200

0 0.5 1 1.5 2

IRI comparison

Xsens

Phone-hard

Phone-velcro

Another Measurement Approach: Whole Body Vibrations

Acceleration Anomaly Passing Zone Determination

Road Surface Condition Estimation

Radius of Curvature Estimation