MIMO CONTROL FOR AUTOMOTIVE COLDSTART

The problem of controlling spark ignition engine emissions during the coldstart period is addressed by designing a model-based MIMO sliding mode controller. The task of the controller is to track a given set of desired profiles of engine-out hydrocarbon (HC) emissions and catalyst temperature using spark timing and fuel injection rate as the inputs. The throttle is not used as a control input. The models used for control design are presented in another paper submitted to the same conference. Different profiles of desired engine-out raw HC and catalyst temperatures are used to analyze the coldstart control problem. Simulation results illustrate the trade-off between low raw HC and fast catalyst ligh-off. It was found that the controller tracks the desired profiles as long as the inputs were not saturated. The controller presented here could be used as a tool to investigate the optimal input profiles. Experiments are being carried out to validate the simulations. Submitted to Fifth IFAC Symposium on Advances in Automotive Control