Error-corrected automatic control system

• US 5,085,190 A
• Filed: 01/29/1991
• Issued: 02/04/1992
• Est. Priority Date: 03/17/1990
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Birk, Manfred, Muller, Norbert, Fenchel, Reinhard, Wessel, Wolf
• Primary Examiner(s): Cross, E. Rollins
• Assistant Examiner(s): Moulis, Thomas N.
• Application Number:
  US07/647,587
• Time in Patent Office: 371 Days
• Field of Search: 123/357, 123/358, 123/359, 123/494, 123/500, 123/501, 123/478
• US Class Current: 123/357
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02D 2250/16 End position calibration, i.e. calculation or measurement of actuator end positions, e.g. for throttle or its driving actuator
• CPC Class Codes: F02D 41/14 Introducing closed-loop corrections
• CPC Class Codes: F02D 41/38 of the high pressure type
• CPC Class Codes: G05B 11/42 for obtaining a characteristic which is both proportional and time-dependent, e.g. P. I., P. I. D.

Abstract

A method for operating an automatic control system for injecting fuel into an internal combustion engine, with the control system having an error correcting capability for deviations that occur in the control signal being processed by the control system, and with the control system having a controlling element, which is embodied as a precontrol, and PI-controller that are operated in parallel.

Claims

1. A method for operating an automatic control system for injecting fuel into an internal combustion engine, with the control system being capable of correcting errors caused by deviations that occur due to operating tolerances of injection system components, and with a controlling element (7), operating as a precontrol (8), and a controller (2) being operated in parallel in the control system, the method comprising:

determining a first deviation signal value (A) substantially in a middle of a regulating range for fuel injection control;

determining a second deviation signal value (M) substantially near one of the end points of the regulating range for fuel injection control; and

feeding the first and second deviation signals to the control system as correction signals for a fuel injection signal being processed by the control system, with the corrections to the fuel injection signal being contemporaneous with a particular operations point of the controller (2).

2. The method according to claim 1, wherein the controller (2) is a PI-controller (4).

3. The method according to claim 1 or 2, wherein the first deviation signal value (A) represents a cumulative error and the second deviation signal value (M) represents a multiplicative error.

4. The method according to claim 3, wherein the feeding step further comprises cumulatively feeding to the automatic control system (1) the first deviation signal value associated with the cumulative error, and multiplicatively feeding the second deviation signal value associated with the multiplicative error.

5. The method according to claim 2, wherein the method further includes transmitting the first deviation signal value (A) to a first summing point (10) at an output (9) of the precontrol (8).

6. The method according to claim 2, wherein the method further includes transmitting the second deviation signal value (M) to a multiplication point (15) at an input of a controller section (3) of the automatic control system.

7. The method according to claim 2, wherein the method further includes determining by interpolation intermediate deviation signal values for the first and second deviation signals that lay between the end points of a control loop for a particular controller operations point existing at a given time, with the intermediate deviation signal values being fed the automatic control system (1).

8. The method according to claim 2, wherein gain of the precontrol (8) corresponds to a reverse average of controlled system gain.

9. The method according to claim 2, wherein the method further includes inputting a signal output from a second summing point (6) to the PI-controller (4), with a setpoint signal (SB_soll) with a positive sign, and an actual signal (SB_ist) with a negative sign coming from an output (18) of a controller section (3), being fed as inputs to the second summing point (6).

10. The method according to claim 9, wherein the setpoint signal (SB_soll) pertains to a start-of-injection setpoint signal, and the actual signal (SB_ist) pertains to a start-of-injection actual signal for injecting fuel into an internal combustion engine, preferably a self-igniting internal combustion engine.

11. The method according to claim 2, wherein the method further includes inputting a setpoint signal (SB_soll) to the precontrol (8).

12. The method according to claim 2, 9, or 11, wherein the method further includes feeding with a positive sign an output (9) of the precontrol (8) and an output of the PI-controller (4) to a third summing point (13).

13. The method according to claim 6, wherein a controller section (3) includes an injection pump of an internal combustion engine.

14. The method according to claim 9, 10, or 11, wherein a setpoint signal (SB_soll) represents a characteristics field value formed from predetermined operating parameters of the internal combustion engine.

15. The method according to claim 7, wherein the interpolating step further includes linear interpolating.