Development of a fuel injection rate measurement method for a vehicle driven with a transient driving patter

A gasoline fuel injection system constructed with an engine control unit (ECU) was
developed to measure the transient fuel injection rate. Various sensor signals from a vehicle driven in the FTP-75 mode with a chassis dynamometer were collected with a data acquisition (DAQ) system. The collected sensor signals were the throttle position sensor (TPS), vehicle speed sensor (VSS), top dead center (TDC) position, crank position sensor (CPS) signal, intake air flow rate, and several other sensor signals. Using a FPGA board and a computer, analog voltage signals equivalent to the TPS, TDC, CPS, VSS and air flow sensor signals were reconstructed from the data collected during the chassis dynamometer experiment. All of the reconstructed sensor signals were inputted into the ECU with a synchronized timing scheme. The injectors were connected to the driver pins of the ECU injector. The injectors driven with the ECU output pins were operated under the same condition used in an actual state of a vehicle. The injected fuel quantities were recorded by a mess cylinder and their overall weight was measured with load cells with a time interval of 0.05 seconds. This fuel injection rate measurement system with both an ECU system and load cells showed that the transient fuel injection rate in the FTP-75 mode could be measured successfully. The developed fuel injection system also showed that it can effectively evaluate fuel injection rates in transient operating conditions of a vehicle.