Combustion Variation Control Strategy with Thermal Efficiency Optimization Consideration in Lean Condition

Abstract A widespread consensus among internal combustion engine researchers is that higher thermal efficiency can be achieved by lean combustion. However the increasing combustion variation is often regarded as the bottleneck of thermal efficiency maximization. In this paper, a combustion variation control strategy with consideration of thermal efficiency optimization is proposed. This proposed strategy consists of two main components. One focuses on cycle-to-cycle and cylinder-to-cylinder variation restrain and another provides the extremum seeking of spark advance for thermal efficiency maximization. The effectiveness and performance of the proposed method are experimentally validated on a production gasoline engine test bench.