Feed-Back Control of Ignition Timing Using Peak Cylinder Pressure Angle with Rough Timing Table 2011-32-0578
Cylinder pressure is used for the closed-loop ignition angle control of a gasoline engine. This paper focused on the crank angle position where the maximum cylinder pressure reached (θPmax) and the relationship between the θPmax and the ignition angle. This closed-loop control set the θPmax a target value with an initial ignition angle and does not need a detailed ignition angle map. Response time and deflection with the target value are examined with a test bench. The θPmax target, ATDC 18 deg. is confirmed in consideration of the effect of knocking and the exhaust gas composition. The target ignition angle was varied step by step within a limit of upper and lower values, the response was observed and each gain was decided. At the engine speed of 5000 rpm, the duration to reach a steady value of θPmax is 0.10 s and the response time of ignition angle is 0.02 s. The response time is almost the same of two crankshaft revolutions; hence, an adequate performance is reliable because it can support the burning of two times. In addition, the change of the θPmax is settled with the standard deviation of value measured at the same level and get enough precision.