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From page 135... ... C-1 A P P E N D I X C Ride Experiment This appendix describes an experiment conducted to correlate objective measurements of ride quality to measures of road roughness on urban and low-speed roadways. The experiment included simultaneous measurements of longitudinal road profile and accelerations at interfaces between the driver and the host vehicle on 29 urban and low-speed pavement sections using 3 test vehicles. Read the entire page →
From page 136... ... C-2 Figure C-1. Instrumented Nissan Altima. Read the entire page →
From page 137... ... C-3 C.2 Instrumentation C.2.1 System Elements The instrumentation is comprised of four primary subsystems, with some additional sensors for diagnostic purposes. All of the equipment was integrated into a measurement platform, which could be moved between the different test vehicles with a minimum of effort. Read the entire page →
From page 138... ... C-4 calibration of the rotational encoders. Figure C-11 shows the optical fifth wheel, and Figure C-12 shows hardware from the RTK GPS. Read the entire page →
From page 139... ... C-5 Figure C-7. Accelerometer mounted to steering knuckle. Read the entire page →
From page 140... ... C-6 Figure C-10.Rotational encoder mounted to a rear wheel. Figure C-11.Optical fifth wheel. Read the entire page →
From page 141... ... C-7 Figure C-12. RTK GPS antenna and receiver. Read the entire page →
From page 142... ... C-8 Figure C-14. Sensor rack, top view. Read the entire page →
From page 143... ... C-9 Figure C-15. Right sensor pod. Read the entire page →
From page 144... ... C-10 C.2.2.3 Vibration Sensors Vehicle vibration sensors included two instrumented seat pads, a floor-mounted vertical accelerometer, and two vertical accelerometers mounted to the steering knuckles. Figures C-17 through C-19 show the locations of each of these sensors and the position of the driver's seat for each vehicle. Read the entire page →
From page 145... ... C-11 Figure C-19. GMC Savana ride sensor locations. Read the entire page →
From page 146... ... C-12 seat centerline. The carpet was cut away in order to allow rigid mounting to the floor pan using standoffs, and a shroud was fabricated to reduce the likelihood of unintentional inputs from the driver's feet. Read the entire page →
From page 147... ... C-13 Table C-3. System sensors. Read the entire page →
From page 148... ... C-14 • Sample rate: 16,000 Hz Encoders: • Resolution: 2048 cycles per rev quadrature (8192 counts per revolution, which is ~0.012 in (~0.3 mm) per count) Read the entire page →
From page 149... ... C-15 C.2.4 Signal Flow The measurement system included a diverse set of sensors and cameras, with diverse outputs and timing. Some sensors provided serial outputs, some provided Ethernet outputs, some provided analog outputs, and others output counter values and digital signals. Read the entire page →
From page 150... ... C-16 The static tests were performed with the engine on but no external disturbances imposed on the vehicle by the operator. Bounce tests with vertical motion were conducted with upward and downward motion imposed on the rear of the vehicle while the profiler remained level. Read the entire page →
From page 151... ... C-17 Table C-4. Test section coordinates by route. Read the entire page →
From page 152... ... C-18 Table C-5. Test section details. Read the entire page →
From page 153... ... C-19 • Section 9: brick surface, crowned intersection crossing, utility covers • Section 10: utility covers, PCC joint distress, crowned intersection crossing • Section 11: brick surface, utility covers • Section 12: utility covers, intersection crossing with PCC panels, transverse cracking • Section 13: utility covers, swell at a junction to the right, grades for drainage, transverse cracking • Section 14: grades for drainage, close-proximity curb at the right lane edge with drainage inlets, patching, transverse cracking • Section 15: PCC crosswalk, crowned intersection crossing, utility covers, close-proximity curb at the right lane edge • Section 16: crowned intersection crossing, bump at a transverse crack • Section 17: passage under railway bridge, AC-to-PCC transition, sealed paving lane joint, sealed transverse cracks, close-proximity curb at the right lane edge with drainage inlets • Section 18: utility covers, crowned intersection crossing, high-severity block cracks that are sealed • Section 19: close-proximity curb at the right lane edge with drainage inlets • Section 20: close-proximity curb at the right lane edge with drainage inlets, swells at junctions to the right, close-proximity driveways to the right • Section 21: railroad crossing • Section 22: drainage inlets at the right lane edge, swells at junctions to the right • Section 23: crowned intersection crossing, intersection crossing with PCC panels, textured pedestrian crossings • Section 24: passage under a railway bridge, utility covers, grades for drainage, close-proximity curb at the right lane edge with drainage inlets • Section 25: crowned intersection crossing, rutted intersection approach, transverse cracks, closeproximity curb at the right lane edge • Section 26: sealed transverse cracks, close-proximity curb at the right lane edge with drainage inlets • Section 27: sealed transverse cracks, sealed longitudinal cracks in the left wheel path, grades for drainage, close-proximity curb at the right lane edge • Section 28: utility covers, swells at junctions to the right • Section 29: utility covers C.5 References "Weight, Height, and Selected Body Dimensions of Adults. United States 1960-1962." U.S. Read the entire page →
From page 155... ... Abbreviations and acronyms used without definitions in TRB publications: A4A Airlines for America AAAE American Association of Airport Executives AASHO American Association of State Highway Officials AASHTO American Association of State Highway and Transportation Officials ACI–NA Airports Council International–North America ACRP Airport Cooperative Research Program ADA Americans with Disabilities Act APTA American Public Transportation Association ASCE American Society of Civil Engineers ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials ATA American Trucking Associations CTAA Community Transportation Association of America CTBSSP Commercial Truck and Bus Safety Synthesis Program DHS Department of Homeland Security DOE Department of Energy EPA Environmental Protection Agency FAA Federal Aviation Administration FAST Fixing America's Surface Transportation Act (2015) FHWA Federal Highway Administration FMCSA Federal Motor Carrier Safety Administration FRA Federal Railroad Administration FTA Federal Transit Administration HMCRP Hazardous Materials Cooperative Research Program IEEE Institute of Electrical and Electronics Engineers ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITE Institute of Transportation Engineers MAP-21 Moving Ahead for Progress in the 21st Century Act (2012) Read the entire page →
From page 156... ... TRA N SPO RTATIO N RESEA RCH BO A RD 500 Fifth Street, N W W ashington, D C 20001 A D D RESS SERV ICE REQ U ESTED ISBN 978-0-309-48060-4 9 7 8 0 3 0 9 4 8 0 6 0 4 9 0 0 0 0 N O N -PR O FIT O R G . Read the entire page →

From page 135...

... C-1 A P P E N D I X C Ride Experiment This appendix describes an experiment conducted to correlate objective measurements of ride quality to measures of road roughness on urban and low-speed roadways. The experiment included simultaneous measurements of longitudinal road profile and accelerations at interfaces between the driver and the host vehicle on 29 urban and low-speed pavement sections using 3 test vehicles.