ENGINE CONTROL SYSTEM AND METHOD

1 . A method of controlling an engine system, the method comprising:

receiving data relating to engine operation;

calculating in an engine model a combustion parameter and an injection parameter required to operate the engine system in accordance with the received engine data;

controlling the engine system based on the calculated injection parameter

wherein the method further comprises adjusting the engine model over time based on a comparison between the calculated engine combustion parameter and a corresponding measured engine combustion parameter.

2 . A method as claimed in claim 1 , wherein the received data relating to engine operation comprises a driver demand parameter.

3 . A method as claimed in claim 1 , wherein the received data relating to engine operation comprises data relating to the engine state and the calculation step comprises a pre-calculation step in which the calculated combustion control parameter is calculated from the engine state data.

4 . A method as claimed in claim 1 , wherein the method comprises measuring in-cylinder pressure and calculating the measured engine combustion parameter from the in-cylinder pressure.

5 . A method as claimed in claim 4 , wherein the in-cylinder pressure is measured for at least one cylinder within the engine system.

6 . A method as claimed in claim 1 , wherein the engine model is adjusted every engine cycle.

7 . A method as claimed in claim 1 , wherein the engine model is adjusted periodically.

8 . A method as claimed in claim 1 , wherein the model comprises one or more model coefficients and the adjusting step comprises calculating updated coefficients based on the comparison of the calculated and measured combustion parameters and storing the updated coefficients in the engine model.

9 . A method as claimed in claim 1 , wherein the calculated engine combustion parameter comprises the centre of combustion and the injection parameter comprises injection timing.

10 . A method as claimed in claim 1 , wherein the calculated engine combustion parameter comprises engine torque and the injection parameter comprises fuel demand.

11 . A method as claimed in claim 1 , wherein the calculating step comprises calculating a global fuel value for the engine system.

12 . A method as claimed in claim 11 , further comprising balancing the fuel value across each cylinder within the engine system such that individual fuel value corrections sum to zero.

13 . A method as claimed in claim 1 , wherein the engine model comprises a fuel efficiency model which is used to calculate a global fuel value for the engine system and a main timing model which is used to calculate a timing value which can be used to determine absolute injection timings for the injectors.

14 . A controller arranged to control an engine system comprising:

inputs arranged to receive data relating to engine operation;

a processor arranged to calculate in an engine model a combustion parameter and an injection parameter required to operate the engine system in accordance with the received engine data;

outputs arranged to output control signals for controlling the engine system based on the calculated injection parameter

wherein the controller further comprises an adjustment arrangement arranged to adjust the engine model over time based on a comparison between the calculated engine combustion parameter and a corresponding measured engine combustion parameter.

15 . A computer readable medium comprising a computer program arranged to configure a computer or an electronic control unit to implement the method according to claim 1 .