Pressure fluctuations determining device for fuel supply system of motor vehicle, has two filters receiving characteristic signal of pressure from pressure sensor in zone of one of injectors, and having different filter characteristics

摘要

The device has two filters receiving a characteristic signal of pressure from a pressure sensor (55) in a zone of one of injectors, and having different filter characteristics. A frequency limit of one filter is selected such that it is higher than a frequency of predictable low frequency pressure fluctuations caused by passage of fuel in a high pressure pump (40) and/or by fall of pressure during injection operation. The other filter has a frequency limit selected such that it is lower than a frequency of predictable high frequency pressure fluctuations produced during injection operation. An independent claim is also included for a method of determination of oscillations of pressure in a fuel supply system.