An Analysis of Next Cycle Control Based on Cylinder Pressure Derived Calculations

This paper examines the detailed timing requirements necessary to implement next cycle control of an internal combustion engine based on values derived from cylinder pressure. A controller consisting of two parts is presented. The first part is found in traditional combustion analysis systems. It records crank-angle resolved cylinder pressure data and reduces it to single point values such as location of peak pressure or location of 50% mass fraction burned. The second part is an engine controller capable of controlling one or more of these analysis parameters. The focus of this paper is on the execution time and latency of the data-path from the sensor to the control value with various engine configurations and calculation methods explored. Some discussion of the data acquisition to controller interface will be included with a focus on practical engine controller latencies and safety systems. An implementation of this system using commercial off the shelf (COTS) hardware and an open software platform are presented.