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Crowd-based Environmental Noise Detection for Robust EVAP Monitor Performance Disclosure Number: IPCOM000244388D
Publication Date: 2015-Dec-08
Document File: 1 page(s) / 367K

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The Prior Art Database

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Crowd-based Environmental Noise Detection for Robust EVAP Monitor Performance

Vehicles sold in North America are required to perform Evap leak detection as part of OBDII requirements. Green states are required to monitor for 0.02" leaks as part of the Clean Air Act Section 177. Federal states and China 6 regulations currently require a 0.04" Evap leak check. There is typically a crowd of vehicles operating in an identical environment each with the same on-board diagnostic system (OBD). A vehicle can report an EVAP fault that is either a true leak or a false alarm. The assumption is that a true leak is a rare occasion compared to a false alarm occurrence. Unfortunately, each vehicle with the MIL on needs to be inspected and many times it is determined that it is a false alarm. With each inspection there is a cost associated and customer dissatisfaction. OBD systems can be unreliable if they make decisions under strong environmental noise conditions such as rainy weather or cold temperatures, certain humidity etc. (Regulations mandate that the OBD must operate even under these circumstances).


This method corrects for false alarms detection due to the environmental noise factors and makes a recommendation whether the results from the OBD judging system are trustworthy or not. This is accomplished by comparing the onboard OBD signals with other vehicles operating in the same- environment neighborhood. If the environmental noises are observed to be influencing...