Objective Testing and Performance Objective Testing and Performance Measurement of Automotive Crash Measurement of Automotive Crash

Warning SystemsWarning Systems

Presented by:

Rick NorcrossNational Institute of Standards and Technology

Authors – Sandor Szabo, Richard Norcross, Joseph Falco

ITS America 2007 Annual Meeting & Exposition June 6, 2007

ITS America 2007 Annual Meeting June 6, 2007

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Objective Test Evaluation Process

Review Crash Data

Conduct tests and Collect DataAnalyze DataReport Results

1 1.2 1.4 1.6 1.8Departure angle (Deg)0.250.50.751

1.251.5

y(m) Distance to barrierat time of warning

Crash Prevention Boundary

crash

no crash

POV1SV

POV2

POV1

Develop Test Scenarios

Specify/Build/Characterize the IMS

Develop Objective Test Procedures

ITS America 2007 Annual Meeting June 6, 2007

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Independent Measurement System (IMS)

Measures key performance values to verify test conducted properly and to evaluate performance of warning system.

ITS America 2007 Annual Meeting June 6, 2007

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Characterize IMS Sensors - StaticStationary Sensor Performance • Part of developing ASTM Standard for 3Di Sensors

– Combined Effort of MEL, BFRL, ATP • Measure error and uncertainty of standard target for

given variable factors and ranges• Results: error is ~1 % 0.1% of range

– (-0.8 m ± 8 cm at 72 m) – IVBSS Spec <5% of range

• (<3.6m @ 72 m)

1 20 40 60 72-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

Nominal Range (m)

Ran

ge E

rror

(m

)

Range Error vs. (Range, All Runs)Instrument Azimuth = 0 deg ; Target Reflectance = 99%; Target AOI = 0 deg;

Run 1

Run 2

Run 3

Variable Factors

Range 1, 20, 40, 72 (m)

Target Reflectance 99, 50, 2 (%)

Target Angle of Incidence 0, 30, 60 (deg)

Instrument Azimuth Angle -60, 0, 60 (deg)

Environment Indoor, Outdoor

Time Day/NightLaser scanner Target

ITS America 2007 Annual Meeting June 6, 2007

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Characterize IMS Sensor - DynamicDynamic Sensor Performance • Set up course of reflective strips at measured distances from a target• Add optic sensor and enhanced GPS to vehicle to detect strips• Drive by target and record time vehicle crosses reflectors • Determine range sensor’s measured distance to target at time when vehicle

crosses reflector

Vehicle traveling at 30 m/s (67 mi/h)

3 cameras

2 laser scanners

Downlookng camera and optical switch

optical reflectors on ground at0, 20, 40 and 60 m

Cylindrical target

ITS America 2007 Annual Meeting June 6, 2007

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Example: Dynamic Error

• Cylinder ranges don’t overlap when vehicle moving (30 m/s) due to error in timing synchronization between sensors

• Right measurements closer than left measurements because vehicle moved between scans. Error proportional to relative velocity

Barrel at 20 m Surveyed reflector

Down view from bumperForward viewRight scanner

Left scanner

GPS Time

ITS America 2007 Annual Meeting June 6, 2007

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IMS Performance Test

• Used police training track in Sykesville, MD

• Focused on performance of laser scanner and ability to meet IVBSS test procedure needs

• Test used was “SV approaches slow moving lead vehicle”

SV approaching slowing POV IBEO range data

ITS America 2007 Annual Meeting June 6, 2007

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IMS Analysis Software

• Extended from RDCWS to support IBEO data analysis

Range data

DV video (30Hz)

IBEO video (10Hz)

Video and range data all synchronized to GPS time

ITS America 2007 Annual Meeting June 6, 2007

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Concluding Remarks

• Accomplishments to Date:– Evaluated IMS range sensor static and dynamic performance

• Initiated upgrade of range sensor to provide longer range, higher angular resolution, wider FOV and improved synchronization

– Developed common IMS sensor mounting bracket for LV and HT– Started IMS integration testing on LV and HT

• Activities in 2007– Evaluate upgraded range sensor static and dynamic

performance– Complete IMS integration testing on LV and HT – Use IMS to evaluate IVBSS performance during phase 1

track and on-road test activities