US Patent 7556023 Control device for high-pressure fuel system

The present invention reduces exhaust emissions at startup, provides improved fuel pressure control performance in a low-load region, and detects high-pressure fuel system abnormalities. Disclosed is a high-pressure fuel system control device which includes a high-pressure pump for pressurizing fuel and discharging the pressurized fuel to a fuel rail, an injector for injecting the fuel stored in the fuel rail, and a fuel pressure sensor for measuring the pressure of the fuel stored in the fuel rail, and controls the high-pressure pump and the injector in accordance with an output generated from the fuel pressure sensor. The high-pressure fuel system control device includes a homo-elasticity coefficient estimation section for estimating a homo-elasticity coefficient of fuel in accordance with a pressure change which occurs when a fuel discharge amount of the high-pressure pump is not smaller than a predetermined value; a fuel pressure estimation section for estimating fuel pressure within the fuel rail in accordance with the homo-elasticity coefficient and control target values for the high-pressure pump and the injector; and a fuel control section for correcting an injection pulse of the injector in accordance with the fuel pressure estimated by the fuel pressure estimation section.