Method and engine control unit
View Patent ↗A method for approximating a stored pilot control map of a pressure control valve of a common-rail pump to the effective of pilot control map of the pressure control valve is presented. The stored pilot control map forms a desired pressure in the rail on a control current of the pressure control valve. The method includes the following method steps a) measurement of the pressure in the rail; b) determination of the control current of the pressure control valve; and c) adaptation of the stored pilot control map by a regression process that includes the pressure measured in step a) and control current measured in step b). In the course of a test run lasting 120 seconds (s) the control deviations (dp) of the desired pressure from the actual pressure in the pressure control valve could be substantially reduced.
1. A method for approximating a stored pilot control map of a pressure control valve of a common-rail pump to the effective pilot control map of the pressure control valve, with the stored pilot control map mapping a desired pressure in the rail on a control current of the pressure control valve, the method comprising the steps of:
a) measurement of the pressure in the rail;
b) determination of the control current of the pressure control valve; and
c) adaptation of the stored pilot control map by means of a regression process including the pressure measured in step a) and the control current measured in step b).
2. The method according to claim 1 , wherein process steps a), b) and c) are iterated.
3. The method according to claim 1 , wherein the stored pilot control map is an analytical function, a sum of analytical functions, a polynomial, especially a third-grade polynomial, a sum of finite elements, a sum of b-spline functions, a sum of linear functions by sections or a table.
4. The method according to claim 1 , wherein method step b) and/or method step c) is/are performed during a non steady-state condition of the common-rail pump.
5. The method according to claim 1 , wherein the regression process is performed by an engine control unit.
6. The method according to claim 1 , wherein the regression process uses unfiltered measurements from step a) and step b).
7. An engine control unit for approximating a stored pilot control map of a pressure control valve of a common-rail pump to the effective pilot control map of the pressure control valve, comprising
a first data storage area for a pilot control map that maps a desired pressure on a control current of the pressure control valve,
a second data storage area for a measured point, especially a measured pressure,
wherein the engine control unit comprises a processor that is programmed in such a way that it adapts a pilot control map stored in the first data storage area by means of a regression process that includes a measured point stored in a second data storage area, and
wherein the engine control unit is operable to
a) measure the pressure in the rail;
b) determine the control current of the pressure control valve; and
c) adapt the stored pilot control map by means of a regression process including the pressure measured in a) and the control current measured in b).
8. The engine control unit according to claim 7 , wherein the engine control unit comprises a processor that is programmed in such a way that the second data storage area is described by a new measured point and the regression process is iterated.
9. The engine control unit according to claim 7 , wherein the stored pilot control map is an analytical function, a sum of analytical functions, a polynomial, especially a third-grade polynomial, a sum of finite elements, a sum of b-spline functions, a sum of linear functions by sections or a table.
10. The engine control unit according to claim 7 , wherein the engine control unit comprises a processor that is programmed in such a way that step b) and/or step c) is/are carried out during a non steady-state condition of the common-rail pump.
11. The engine control unit according to claim 7 , wherein the engine control unit comprises a processor that is programmed in such a way that the regression process uses unfiltered measurements from step a) and step b).
12. A method for approximating a stored pilot control map of a pressure control valve of a common-rail pump to the effective pilot control map of the pressure control valve, the method comprising the steps of:
measuring the pressure in the rail;
determining the control current of the pressure control valve; and
adapting the stored pilot control map by means of a regression process including the measured pressure and the control current.
13. The method according to claim 12 , wherein the process steps are iterated.
14. The method according to claim 12 , wherein the stored pilot control map is an analytical function, a sum of analytical functions, a polynomial, especially a third-grade polynomial, a sum of finite elements, a sum of b-spline functions, a sum of linear functions by sections or a table.
15. The method according to claim 12 , wherein measuring and/or adaptation is/are performed during a non steady-state condition of the common-rail pump.
16. The method according to claim 12 , wherein the regression process is performed by an engine control unit.
17. The method according to claim 12 , wherein the regression process uses unfiltered measurements.