Motoring an engine and injecting fuel to determine fuel properties by measuring cylinder pressure

A method of controlling an engine, comprising the steps of:

• during motoring of the engine, injecting, by an injector, fuel for analysis into a cylinder of the engine at a specific timing after an intake valve of the cylinder is closed;
• acquiring, by a controller, a crank angle period from a start timing of the fuel injection to a timing of a pressure inside the cylinder reaching a reference pressure, in response to signals of a crank angle sensor and an in-cylinder pressure sensor;
• and
• determining, by the controller, a property of the fuel injected by the injector by comparing the acquired crank angle period with a reference crank angle period, the reference crank angle period being from an injection start timing when a standard fuel is injected into the cylinder to a timing of the pressure inside the cylinder reaching the reference pressure, wherein
• the controller corrects at least one of a fuel injection amount, a fuel injection timing, and a close timing of the intake valve according to the property of the fuel, after startup of the engine is finished,
• when the acquired crank angle period is longer than the reference crank angle period, the controller corrects the close timing of the intake valve to an advancing side, and when the acquired crank angle period is shorter than the reference crank angle period, the controller corrects the close timing of the intake valve to a retarding side, and
• the controller corrects the close timing of the intake valve so that the close timing of the intake valve is advanced when the acquired crank angle period is longer than the reference crank angle period, and when the acquired crank angle period is longer than the reference crank angle period by a given value or more, the controller increases the fuel injection amount by correcting the start timing of the fuel injection to the advancing side and correcting an end timing of the fuel injection to the retarding side.

A method of controlling an engine, comprising the steps of:

• during motoring of the engine, injecting, by an injector, fuel for analysis into a cylinder of the engine at a specific timing after an intake valve of the cylinder is closed;
• acquiring, by a controller, a crank angle period from a start timing of the fuel injection to a timing of a pressure inside the cylinder reaching a reference pressure, in response to signals of a crank angle sensor and an in-cylinder pressure sensor;
• and
• determining, by the controller, a property of the fuel injected by the injector by comparing the acquired crank angle period with a reference crank angle period, the reference crank angle period being from an injection start timing when a standard fuel is injected into the cylinder to a timing of the pressure inside the cylinder reaching the reference pressure, wherein
• the controller corrects at least one of a fuel injection amount, a fuel injection timing, and a close timing of the intake valve according to the property of the fuel, after startup of the engine is finished,
• when the acquired crank angle period is longer than the reference crank angle period, the controller corrects the close timing of the intake valve to an advancing side, and when the acquired crank angle period is shorter than the reference crank angle period, the controller corrects the close timing of the intake valve to a retarding side, and
• the controller reduces the fuel injection amount by correcting the close timing of the intake valve so that the close timing of the intake valve is retarded when the acquired crank angle period is shorter than the reference crank angle period.