Abstract
New improved direct fuel injector with cylinder pressure sensor has a charge amplifier installed inside the injector. The charge amplifier converts the output of the cylinder pressure sensor into a voltage. Just as before, the cylinder pressure sensor uses langatate (Lanthan gallium tantalate) single crystal as the piezoelectric element, and it is installed at the tip of the injector. This successfully reduced ignition signal noise, noise from the injector being driven, and other noise. And Torque control system using this prototype sensor is made up of a sliding mode controller and parameter identifier. The parameter identifier keeps tracking automatically, even when the target air-fuel ratio switches from stoichiometric to lean mode. Control result is good when the driving A/F is deliberately changed from stoichiometric for normal driving to lean, and the vehicle is driven in LA4 mode. Torque control data sampled at 10-msec intervals, the standard deviation is 8.2 Nm, and the deviation between engine torque and target torque remains 95% within Δ16.4 Nm.This paper presents about its performance.
