Method for controlling an internal combustion engine

Abstract

A method for controlling an internal combustion engine equipped with fuel injectors connected to a fuel supply rail supplied with fuel by a fuel pump, the internal combustion engine being controlled according to an operating-point setpoint, the method comprising the following steps: determining whether a new operating-point setpoint different from the ongoing operating-point setpoint has been received, if it has, determining the maximum capacity of the pump according to determined values for the rotational speed of the internal combustion engine, for the quantity of fuel injected and for the fuel pressure in the injection common rail, determining the rate of fuel consumption of the vehicle; subtracting the rate of fuel consumption of the vehicle from the maximum capacity of the pump in order to obtain the remaining capacity of the fuel pump, determining the difference in the fuel delivery rate between the ongoing operating point and the operating point for the new operating-point setpoint, and if the remaining capacity of the fuel pump is less than the difference in fuel delivery rate, a reduced fuel delivery rate gradient setpoint is emitted with the new operating-point setpoint or the quantity of fuel injected is limited.

Description

technical field [0001] The technical field of the invention is the control of internal combustion engines, and more precisely the control of fuel pumps of such engines. Background technique [0002] The internal combustion engine comprises injectors fed by a common injection rail, the pressure and fuel inlet of which are regulated by a fuel pump. The fuel pump is driven by the internal combustion engine and is dimensioned according to the point defonctionnement of the engine, in particular according to the performance of the engine. On the other hand, mechanical drive stress requires a controlled resistance torque of the pump. [0003] For each engine, a pressure gradient that must be able to be achieved by the fuel pump is specified so that the pressure in the common injection rail varies within a predetermined time depending on the operating point of the engine. [0004] Likewise, a diagnostic system is required to monitor the activity of the pump and signal an error whe...

AI Technical Summary

Problems solved by technology

Also, during transition phases related to some specific operating situations (anti-pollution regeneration, etc.), additional fuel flow may be required compared to that required at the current operating point

Depending on the amount of extra flow required, the fuel pump may not be able to provide the specified pressure gradient

On the other hand, the reuse of existing engines associated with new pollution control standards and with performance levels expected by motorists limits pumping volumes and exacerbates the problem

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