Post on 30-Dec-2015
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
2
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
3
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