SYSTEM AND METHODS OF INTEGRATED CONTROL OF COMBUSTION AND SCR SYSTEMS

An emissions control system for a motor vehicle that includes an internal combustion engine includes a first selective catalytic reduction (SCR) device and a reductant injector, The system further includes a model-based controller that is configured to calculate a target amount of reductant to inject to maintain a predetermined ratio between an amount of NH3 and an amount of NOx at the outlet of the first SCR device, and to send a command for receipt by the reductant injector to inject the calculated amount of reductant. The model-based controller is further configured to send a command for receipt by an engine controller to influence NOx production by the engine by modifying an engine operating parameter, based on a calculated target amount of NOx at the inlet of the first SCR device.