Next-Cycle and Same-Cycle Cylinder Pressure Based Control of Internal Combustion Engines

This paper reviews next-cycle and same-cycle control techniques developed by Drivven and implemented at Argonne National Laboratory on a General Motors 1.9L common rail diesel engine. Next-cycle control involves measuring cylinder pressure engine-synchronously, performing calculations, and using the complete result in the control algorithm for the fueling event in the next engine cycle. For this control method, injection timing was manipulated to maintain a specified 50% burn location and was investigated in both single-cylinder and multi-cylinder modes. The engine was tested in steady state with step changes in input parameters such as EGR rate. Similar to next-cycle control, same-cycle control involves measuring cylinder pressure engine-synchronously, performing calculations, and making fueling decisions based on partial results within the same engine cycle. For this control method, injection pulse spacing was manipulated to optimize secondary injections by a heat-release calculated angle-by-angle. Next-cycle and same-cycle control both have the capability of enhancing production engine control while next-cycle control also has great benefits as a calibration aid.