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CMEM - NCHRP Project 25-11 Data Set

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A total of 327 vehicle tests were performed during the first project phase of which 315 vehicle tests are considered valid and are included in the CMEM Project CD. An additional 31 vehicles were tested in the fourth phase and are also included in the CMEM Project CD (test numbers 400 and above). Vehicles were typically tested over the following three test cycles:

1. 3-bag FTP (Federal Test Procedure)

The FTP cycle is part of the standard certification test procedure and provides baseline information about a vehicle's emissions which can be used as a reference when comparing with existing vehicle tests. The FTP test data also provides cold and warm start information.

2. US06 cycle (Bag 4 of the Supplemental FTP)

The high speed US06 test cycle targets "off-cycle", non-FTP operation that is more characteristic of modern driving patterns.

3. MEC cycle (In-house designed modal emission cycle)

The modal emission cycle (MEC) was specially designed and included to provide emission data that can more easily be matched to specific driving modes: various steady-state cruise speeds, accelerations, decelerations, and idle.

Vehicle testing was performed by CE-CERT's Vehicle Emission Research Laboratory (VERL) and test data were processed and recorded by CE-CERT's Transportation Systems Research (TSR) group. Vehicle test data sets are referred to by their TSR assigned test number. Emission data is presented in Excel workbooks and is given in mass emission rate units of grams per second.

Valid vehicle parameter data were collected on 67 vehicles using a Scan Gra-FixTM datalogging tool connected to the vehicle ECU (engine control unit) during testing. Data were collected for all vehicles supported by the tool when used with a 1994 and later Domestic Combination Primary cartridge, a 1993 GM Primary cartridge, or a 1992 and later Asian Import Primary cartridge. With this it was possible to directly obtained measurements of vehicle parameters such as engine speed, throttle position, etc. The vehicle data variables change from model-to-model and year-to-year so the variables included in the files are not standardized.


For more specific information about the database contents of the CD, please refer to the following:


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