Engine Control for Multiple Combustion Optimization Devices

A number of variables in a conventional automotive powertrain are scheduled on-line based on the current operating conditions with the goal to achieve the best fuel economy (FE), emissions, and performance. The functions are obtained off-line, i.e. after a mapping, data regression, and optimization process followed by in-vehicle calibration for fine-tuning the powertrain behavior. More complex engines, referred to as high degree of freedom (HDOF) engines, require a careful tradeoff between the mapping, optimization, and calibration time on one hand and the achieved accuracy on the other. Additionally, the powertrain control module (PCM) has limited computational resources. Thus, fully representing the more complex functions can be prohibitive. As a result, an HDOF powertrain in actual operation may not completely achieve the potential benefits the new technologies offer. In the case of optimum combustion phasing one can determine how successful a calibrated powertrain is by analyzing in-cylinder pressure or ionization signal. Moreover, when the required sensors become available in production vehicles, closing the control loop may provide additional accuracy and shift the complexity-accuracy tradeoff equation for HDOF engines.