Is cylinder pressure-based control required to meet future HD legislation?

This work aims to determine the potential and benefits of cylinder pressure-based control (CPBC) to meet future emission legislation for heavy-duty automotive applications. Focus is on resulting engine performance. From a literature study, it is seen that CPBC is a crucial enabler for ultra high efficient and clean combustion concepts, such as PPC and RCCI. For these advanced concepts, combustion phasing and heat release control is key to guarantee stable and safe operation. RCCI also supports the transition towards sustainable fuels by allowing for the use of a wide range of fuels. In addition, CPBC is seen to reduce the calibration effort and to improve performance robustness for all combustion concepts. This results in reduced engine out emission dispersion and improved torque response. Installation of cylinder pressure sensors opens the route to real-time and robust estimation and monitoring of fuel efficiency, combustion noise, and NOx and opacity emissions. This permits new OBD functionality and sensor removal, and thus system cost reduction. For PPC and RCCI, the main control challenges are stable operation with maximal efficiency over the full load range, transient control, and fuel flexibility. To fully exploit the CPBC potential, better understanding of coordinated air-fuel path control, self-learning control capabilities for on-line fuel optimization, and in-cycle control of the heat release shape is needed.