Method for regulating the rotational speed of an internal combustion engine

• US 7,182,064 B2
• Filed: 01/20/2004
• Issued: 02/27/2007
• Est. Priority Date: 01/22/2003
• Status: Active Grant

• Current Assignee: MTU Friedrichshafen GmbH (Rolls-Royce Holdings Plc)
• Original Assignee: MTU Friedrichshafen GmbH (Rolls-Royce Holdings Plc)
• Inventors: Dolker, Armin, Butscher, Franz
• Primary Examiner(s): MILLER, CARL STUART
• Application Number:
  US10/542,502
• Publication Number:
  US 20060118083A1
• Time in Patent Office: 1,134 Days
• Field of Search: 123/357, 123/350, 123/352, 123/198.D, 123/339.12, 123/339.19, 123/339.2, 702/96, 702/142
• US Class Current: 123/352
• CPC Class Codes: F02D 2041/142 using different types of control law in combination, e.g. adaptive combined with PID and sliding mode
• CPC Class Codes: F02D 2200/604 Engine control mode selected by driver, e.g. to manually start particle filter regeneration or to select driving style
• CPC Class Codes: F02D 31/009 for maximum speed control
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/3809 Common rail control systems common rail apparatus F02M55/025, F02M63/0225
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method for closed-loop speed control of an internal combustion engine that is provided as a generator drive or a marine propulsion unit, including the steps of: computing a first control deviation (dR1) from a speed variance comparison; computing a first set injection quantity (qV0) from the first control deviation (dR1) by a speed controller; determining a second set injection quantity (qV) from the first set injection quantity (qV0) and another input variable (E) by a minimum value selector for the closed-loop speed control of the internal combustion engine, wherein in a first, steady operating state of the internal combustion engine, the input variable (E) corresponds to a first injection quantity (qV1) (E=qV1), which is computed via a first characteristic curve, and in a second, dynamic operating state of the internal combustion engine, the input variable (E) corresponds to a second injection quantity (qV2) (E=qV2), which is computed via a second characteristic curve; and changing from the first characteristic curve to the second characteristic curve when a changeover condition is satisfied.

Claims

1. A method for closed-loop speed control of an internal combustion engine that is provided as a generator drive or a marine propulsion unit, comprising the steps of:

computing a first control deviation (dR1) from a speed variance comparison;

computing a first set injection quantity (qV0) from the first control deviation (dR1) by a speed controller;

determining a second set injection quantity (qV) from the first set injection quantity (qV0) and another input variable (E) by a minimum value selector for the closed-loop speed control of the internal combustion engine, wherein in a first, steady operating state of the internal combustion engine, the input variable (E) corresponds to a first injection quantity (qV1) (E=qV1), which is computed via a first characteristic curve, and in a second, dynamic operating state of the internal combustion engine, the input variable (E) corresponds to a second injection quantity (qV2) (E=qV2), which is computed via a second characteristic curve; and

changing from the first characteristic curve to the second characteristic curve when a changeover condition is satisfied.

2. The method for closed-loop speed control in accordance with claim 1, wherein the changeover condition is satisfied when the first control deviation (dR1) becomes negative (dR1<

0) and falls below a limit (GW) (dR1<

GW).

3. The method for closed-loop speed control in accordance with claim 2, including initializing the second characteristic curve with a value (qV1(tS)) of the first injection quantity (qV1) at a changeover time (tS) when the changeover condition is satisfied.

4. The method for closed-loop speed control in accordance with claim 2, including initializing the second characteristic curve with a value (qV0(tS)) of the first set injection quantity (qV0) at a changeover time (tS) when the changeover condition is satisfied.

5. The method for closed-loop speed control in accordance with claim 4, including initializing the second characteristic curve with a larger value than the first set injection time (qV0) at the changeover time (tS) when the changeover condition is satisfied.

6. The method for closed-loop speed control in accordance with claim 2, including using the second characteristic curve to reduce the second injection quantity (qV2), starting from an initialization value, to zero (qV2=0) or to a default value (qMIN) according to a transient response (qV2=qMIN).

7. The method for closed-loop speed control in accordance with claim 6, wherein the default value (qMIN) is smaller than an idling injection quantity (qLL).

8. The method for closed-loop speed control in accordance with claim 1, further including a second control deviation (dR2) and the changeover condition is satisfied if the second control deviation (dR2) becomes negative (dR2<

0) and falls below a limit (GW) (dR2<

GW).

9. The method for closed-loop speed control in accordance with claim 8, wherein a first filtered actual speed (nM1(IST)) is a critical value for determining the first control deviation (dR1), and a second filtered actual speed (nM2(IST)) is a critical value for determining the second control deviation (dR2), such that the first filtered actual speed (nM1(IST)) and the second filtered actual speed (nM2(IST)) are computed from the actual speed (nM(IST)) of the internal combustion engine by a first filter and a second filter, respectively.

10. The method for closed-loop speed control in accordance with claim 9, wherein the first filter detects a larger crankshaft angle than the second filter.

11. The method for closed-loop speed control in accordance with claim 1, including setting the input variable (E) of the minimum value selector as a limiting value for an integral component of the speed controller.