Patent ID: 8433498

Claim:
A method for controlling a rail pressure in a fuel supply system comprising a fuel pump, at least one injector and a rail connecting the at least one injector to the fuel pump, comprising the steps of: calculating a static leak rate of the at least one injector based on said rail pressure and a temperature of the fuel, the static leak rate being independent from an excitation time of the at least one injector; calculating a dynamic leak rate of the at least one injector based on the static leak rate and the excitation time of the at least one injector; establishing a relationship between said rail pressure and an engine-speed weighted sum of at least the static leak rate and the dynamic leak rate of the at least one injector; estimating a fuel drain rate from said rail based on a fuel injection rate, said rail pressure and said relationship between said rail pressure and the engine-speed weighted sum of at least the static leak rate and the dynamic leak rate of the at least one injector; estimating a desired intake flow rate of said fuel pump based on said fuel drain rate; and controlling the fuel pump to operate at said desired intake flow rate.