Multi-Cylinder HCCI Control With Cam Phaser Variable Valve Actuation Using Model Predictive Control

Recent work in the area of Homogenous Charge Compression Ignition (HCCI) engine control has focused on the use of variable valve timing (VVT) as a near term implementation strategy. Control of valve timing has a significant influence on combustion phasing and can be implemented with cam-based VVT systems already available in production vehicles. However, cam-based VVT systems pose a challenge by introducing cylinder coupling via a shared actuator. This paper presents a Model Predictive Control (MPC) framework that explicitly accounts for this inter-cylinder coupling as a constraint on the system. The prediction time step of this MPC controller differs from the execution time step, enabling consideration of shared actuation among otherwise independent systems. Experimental results on a multi-cylinder HCCI engine test bed provide validation of this controller.