Method for computing an ignition angle of an internal combustion engine

• US 20050143900A1
• Filed: 11/29/2004
• Published: 06/30/2005
• Est. Priority Date: 12/20/2003
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Goebels, Jochen, Dierssen, Kai, Eichhorn, Rudi, Meinken, Andreas, Sloboda, Robert, Kantschar, Anton, Boettger, Jan, Stelzenmueller, Goetz, Gabel, Frederic
• Granted Patent: US 7,051,712 B2
• Time in Patent Office: Days
• US Class Current: 701/111
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02D 41/2451 characterised by what is learned or calibrated
• CPC Class Codes: F02P 5/1523 with particular laws of return to advance, e.g. step by step, differing from the laws of retard
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for computing an ignition angle of an internal combustion engine as a function of the operating conditions of the engine and knock signals K, which indicate knocking combustion in the engine. If knock occurs, the ignition angle is retarded. If knock stops for a first period, the ignition angle is advanced again. Advance of the ignition angle is limited on the basis of the first period. If knock stops for a second period, which exceeds the first period, the ignition angle is further advanced.

Claims

1. A method for computing an ignition angle of an internal combustion engine as a function of operating conditions of the engine and knock signals, which indicate knocking combustion in the engine, the method comprising:

retarding the ignition angle if knock occurs; and

advancing the ignition angle in the absence of knock for a first period, wherein the advance of the ignition angle is limited on the basis of the first period, and in the absence of knock for a second period, which exceeds the first period, the ignition angle is advanced.

2. The method according to claim 1, wherein the first and second periods are defined as time periods.

3. The method according to claim 1, wherein the first and second periods are defined as number of combustion processes of the engine.

4. The method according to claim 1, wherein the operating conditions include a rotational speed of the engine.

5. The method according to claim 1, wherein the operating conditions include a load of the engine.

6. The method according to claim 1, further comprising, to compute the ignition angle, computing and adding together a basic ignition angle and a knock control ignition angle, the knock control ignition angle being retarded if knock occurs, and advanced if knock does not occur for the first period.

7. The method according to claim 6, further comprising advancing the basic ignition angle if no knock occurs for the second period.

8. The method according to claim 6, further comprising retarding the basic ignition angle if the knock control ignition angle is retarded beyond a comparison value for a third period.

9. The method according to claim 8, further comprising using averaging to determine that the knock control ignition angle has been retarded excessively.

10. The method according to claim 1, wherein the engine is a multicylinder engine, and the ignition angle is computed individually for each cylinder.

11. The method according to claim 1, wherein the engine has a plurality of cylinders, and further comprising:

computing a knock control ignition angle individually for each of the cylinders; and

one of advancing and retarding basic ignition angles of all of the cylinders jointly.