Patent ID: 8095294
Filing Date: 2012-01-10
Classification: F02D,F02M,Y02T

Abstract:
1. A method of determining fuel injection on-time for an internal combustion engine fuelled with a gaseous fuel that is injected directly into a combustion chamber through a fuel injection valve, the method comprising: (a) storing predetermined injection on-time values in a plurality of look-up tables, with on-time in each look-up table being a function of gaseous fuel rail pressure and fuelling amount and with each table associated with a fixed value for a third parameter, which correlates to in-cylinder pressure; (b) sending input data to a controller, said controller determining from said input data, values for said gaseous fuel rail pressure, said fuelling amount and said third parameter; (c) identifying from said plurality of predetermined look-up tables two look-up tables which are associated with said fixed values for said third parameter that are closest in value to that of said third parameter determined in step (b); (d) retrieving respective injection on-times as a function of gaseous fuel rail pressure and fuelling amount from said two look-up tables identified in step (c); and (e) determining a desired injection on-time by interpolating between injection on-time values retrieved in step (d) based on the value of said third parameter determined in step (b).