Patent ID: 7630823

Claim:
A high-pressure fuel injection system for controlling the fuel injection event in an internal combustion engine mounted in a vehicle and having an engine block with one or more cylinders within which fuel is injected, the fuel injection system comprising: a high-pressure fuel pump in fluid communication with a fuel reservoir; a fuel accumulator, in fluid communication with the high-pressure fuel pump; one or more injectors that are in fluid communication with the fuel accumulator and each of the fuel injectors are in fluid communication with a corresponding cylinder in which a piston is supported; the one or more injectors having a valve that opens or closes responsive to electrical pulses; a controller, in electrical communication with the one or more of the injectors and the high-pressure fuel pump that, during operation of the engine, generates one or more first signals responsive to which the valve in the injector opens or closes and one or more second signals responsive to which the high-pressure fuel pump increases or decreases the pressure level in the fuel accumulator; one or more sensors for detecting operating parameters, during operation of the engine, comprising a temperature of air in an air manifold, a pressure within the air manifold and a barometric pressure, wherein the barometric pressure is an ambient atmospheric pressure external of the vehicle or fuel injection system; wherein the one or more sensors send data, indicative of these operating parameters, to the controller; and, the controller is programmed to estimate an in-cylinder gas density during operation of the engine using data received from the sensors.