Research Projects

Project at a Glance

Project Status: complete

Report Published January 1994:

Title: Task order contract for emissions inventory projects. Vehicle Location Systems. Development of an onboard data acquisition system for recording vehicle operating characteristics and emissions.

Principal Investigator / Author(s): Digenova, Frank

Contractor: Sierra Research, Inc.

Contract Number: a096-214

Research Program Area: Emissions Monitoring & Control

Topic Areas: Mobile Sources & Fuels, Stationary Sources


Under Contract No. A096-214, Sierra Research Inc. (Sierra) was retained by the California Air Resources Board (ARB) to conduct the following tasks related to improving ARB's inventory of emissions from motor vehicles: 1) document in-use vehicle activity; 2) investigate radio transponders; and 3) help oversee and direct evaporative emissions tests. In addition, the contract called for conducting other unspecified (general) tasks.

Task 1, originally called for the development and use of a portable vehicle instrumentation package. At the direction of ARB's Mobile Source Division, this task was modified to provide a less portable but more comprehensive instrumentation package and to install it in a state-owned Chevrolet Lumina. A summary of that instrumentation work is provided below and a detailed report entitled, "Development of an Onboard Data Acquisition System for Recording Vehicle Operating Characteristics and Emissions," is provided as an attachment to this report.

Task 2, investigation of radio transponders, specified the investigation and demonstration of the use of vehicle-based transponders to relay on-board emission control related information to a roadside base station or receiver, and the analysis of legal issues surrounding possible use of transponders. A legal analysis of transponder technology covering licensing, liability, constitutional and other issues was prepared under this task and was submitted to ARB on June 23, 1993. A copy of the report is included as an appendix to this report.

The technical investigation and demonstration of transponder use under Task 2 was redirected by ARB Mobile Source Division staff to focus on reading and transmitting "fault codes." Reading of fault codes from the Lumina's onboard electronic control unit, including sample data, was investigated and demonstrated, as described in Section 5.1 of the vehicle instrumentation report (attached). Transmitting fault codes without dedicated transponder equipment designed for that purpose was investigated but was found to be impractical within the budget constraints of the current project. A transponder and base station system capable of determining whether a vehicle's malfunction indicator light (MIL) is illuminated will be delivered to ARB by Sierra's subcontractor, Hughes, as soon as the terms of a bailment agreement between ARB and Hughes have been successfully finalized.

Task 3, directed Sierra to help oversee, direct and interpret results of evaporative testing conducted by ATL under ARB sponsorship. Detailed test results from this program have been provided to APB under separate cover.

Task 4, provided resources for miscellaneous emissions inventory related support to the ARB. At the direction of ARB Mobile Source Division staff, these resources were used to augment Task 1 in order to pursue further specific elements of the vehicle instrumentation package described above.

As outlined above, work performed under the contract covered four specific areas:

* Development of an Enhanced Vehicle Instrumentation Package for the Characterization of In-Use Vehicle Operation and Its Effect on Emissions
* Investigation, Including Legal Analysis, of the Use of Vehicle Transponders to Obtain and Transmit On-Board Data; Investigation of the Feasibility of On-Board Vehicle Location Systems; and
* Overseeing, Direction and Interpretation of Evaporative Emissions Testing by ATL for ARB.

In addition, the following miscellaneous motor vehicle emissions inventory related tasks were performed: 1) obtained an 'Autoscope" unit that can be used to monitor various traffic parameters, 2) performed analysis to assist ARB staff in their on-road motor vehicle cycle development work and 3) performed I/M related analyses.

The remainder of this report provides summary descriptions of the work performed. The appendix and attachments to this report document the detailed information, methods and findings from the investigations conducted under the contract. Information relating to testing by ATL has been submitted to ARB under separate cover and will not be discussed further in this report.


For questions regarding this research project, including available data and progress status, contact: Heather Choi at (916) 322-3893

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