Sensors Midwest 2017

OBD standards are now driving the need for real-time diagnosis of aftertreatment system emissions performance over the life of the vehicle.  This system diagnosis requires the integration of information from a growing number of sensors in the vehicle exhaust pipe: NOx/NH3 sensors, soot load and particulate distribution sensors, temperature sensors, delta-pressure sensors, DEF and gas assist dosing pressure sensors, and DEF sensors including level, concentration/quality, and temperature are now becoming standard.  In addition to allowing control of the aftertreatment system and compliance to certification limits, improving sensor diagnostic functionality allows the OEM system to monitor the state of system health in real time.   These OBD sensors are becoming the guardrails that allow aftertreatment systems to meet required standards. In this context it is clear that OBD requirements at the vehicle level translate into reliability, performance, and self-diagnostic capabilities at the sensor level.  After a detailed description of the context, this talk will cover a number of tools that are employed today to ensure that the OBD compliance of emissions sensors is matched to the vehicle system during its development and integration phases.