Abstract:
A diesel exhaust fluid (DEF) control system includes: a target module configured to determine a target rate of injection of a DEF by a DEF injector; an adjustment module configured to determine an adjustment based on a concentration of urea in the DEF; an adjusting module configured to adjust the target rate based on the adjustment to produce an adjusted rate of injection of the DEF by the DEF injector; and an injector control module configured to control injection of the DEF by the DEF injector based on the adjusted rate.
Abstract:
Technical solutions are described for limiting exposure of components of an emissions control system to rich exhaust conditions. An example an emissions control system includes an oxygen storage component; and a controller that limits exposure of the oxygen storage component to rich exhaust conditions. The limiting includes determining an air-to-fuel equivalence ratio in exhaust gas in response to an engine receiving a request to generate torque, the request including a displacement of a pedal; determining an amount of oxygen in the exhaust gas based on the air-to-fuel equivalence ratio; determining an oxygen level stored by the oxygen storage component; and if the oxygen level is above a predetermined threshold, lowering a torque generation rate of the engine, which specifies amount of torque generated per unit displacement of the pedal.
Abstract:
An emissions control system includes a Selective Catalytic Reduction device adapted to reduce emissions, an injector adapted to inject a reductant into the device, a NOx sensor disposed downstream of the device, a controller, an iterative model, and a table. The controller is configured to perform short and long term control by confirming at least one short term criteria is met. Once confirmed, the controller calculates a normalized model error utilizing the model and a signal received from the sensor, and integrates the normalized model error. If the integrated normalized model error exceeds a threshold, the controller proceeds toward the long term control. If a long term criteria is met, a current long term factor and the integrated normalized model error is applied to the table to determine a new long term factor. The new long term factor is multiplied against an energization time of the injector.
Abstract:
Technical solutions are described for an emissions control system for a motor vehicle including an internal combustion engine. An example computer-implemented method for controlling an exhaust system of an internal combustion engine, includes detecting a high hydrocarbon region in the operation of the internal combustion engine. The method further includes responsively, measuring an upstream temperature of an oxidation device of the exhaust system. Further yet, the method includes in response to the upstream temperature being equal to or above a predetermined threshold, delaying an O2 diagnosis of the exhaust system for a signal rationality delay time.
Abstract:
Embodiments of the invention include a method for performing diagnostics of a selective catalytic reduction (“SCR”) device in an exhaust gas treatment system of an internal combustion engine. The method includes monitoring an amount of sulfur in the SCR device of the exhaust treatment system and monitoring, by an SCR diagnostics module, an efficiency of the SCR device and indicating when the efficiency of the SCR device falls below an efficiency diagnostics threshold. Based on determining that the amount of sulfur in the SCR device is above a first threshold, the method includes disabling an operation of the SCR diagnostics module.