History and Background
Event Data Recorders (EDRs) in passenger cars (primarily in the Airbag Control Module) have attracted a great deal of media interest over the past several years. Comparatively speaking, much less attention has been paid to EDRs in heavy trucks and commercial motor vehicles (CMVs).
Beginning in 1993, the Environmental Protection Agency tightened emissions requirements for diesel engines in CMVs. In response, engine manufacturers began using electronic (i.e., computerized) engine control units. These computers enhanced the precision of injector timing, the fuel/air mix, and other mechanical factors, creating more efficient and cleaner engines.
As computer hardware prices dropped, design engineers could incorporate more features into these Engine Control Modules (ECMs). ECMs then began to monitor data that were of interest to logistics, safety, and maintenance professionals. By 1995, most ECMs monitored data such as fuel economy, time at idle, active fault codes (problems in the engine), and the amount of time that a truck spent in various speed bands, including how often it exceeded a pre-set maximum-tolerable speed.In 1997, the National Transportation Safety Board (NTSB) recommended that NHTSA should “pursue gathering crash information from EDRs.” In late 1997 and early 1998, EDR capability became a standard feature in several HV ECMs. These EDRs can store data about wheel speed, brake status, cruise control, and several other factors. Most EDRs are set to record these data when a sudden change in wheel speed is detected.
|© Heavy Truck EDR | Disclaimer||Messerschmidt Safety Consultants | Bloomberg Consulting | Armstrong Forensic Engineers | Yosko Consulting|