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 (θ_Pmax) and the relationship between the θ_Pmax and the ignition angle. This closed-loop control set the θ_Pmax 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 θ_Pmax 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 θ_Pmax 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 θ_Pmax is settled with the standard deviation of value measured at the same level and get enough precision.