METHODS FOR VARIABLE DISPLACEMENT ENGINE DIAGNOSTICS

• US 20100031738A1
• Filed: 08/06/2008
• Published: 02/11/2010
• Est. Priority Date: 08/06/2008
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Feldkamp, Timothy Mark, Feldkamp, Lee Albert
• Granted Patent: US 7,900,509 B2
• Time in Patent Office: Days
• US Class Current: 73/114.790
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02D 13/06 Cutting-out cylinders
• CPC Class Codes: F02D 19/0689 for in-cylinder direct injection
• CPC Class Codes: F02D 19/084 Blends of gasoline and alcohols, e.g. E85
• CPC Class Codes: F02D 2041/0012 with selective deactivation of cylinders
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/1405 Neural network control
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: G01M 15/042 by monitoring a single specific parameter not covered by groups G01M15/06 - G01M15/12
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Various methods are described for monitoring cylinder valve deactivation in an engine, the engine including at least a cylinder valve actuator for deactivating at least a cylinder of the engine. One example method comprises indicating degradation of the valve actuator based on crankshaft acceleration.

Claims

1. A method for monitoring cylinder valve deactivation in an engine, the engine including at least a cylinder valve actuator for deactivating at least a cylinder of the engine, the method comprising:

indicating degradation of the valve actuator based on crankshaft acceleration.

2. The method of claim 1 wherein monitoring cylinder valve deactivation includes monitoring cylinder valve deactivation following a transition between an activated and a deactivated mode of cylinder operation.

3. The method of claim 1 wherein indicating degradation of the valve actuator based on crankshaft acceleration includes indicating degradation of the valve actuator based on crankshaft acceleration of a plurality of firing events.

4. The method of claim 3 wherein the plurality of firing events includes firing events during one complete engine cycle.

5. The method of claim 1 wherein the cylinder valve actuator includes a cylinder valve actuator that deactivates a plurality of cylinders.

6. The method of claim 1 where the engine includes 6 or more cylinders.

7. The method of claim 1 where the engine includes 8 or more cylinders.

8. The method of claim 3 wherein a crankshaft acceleration pattern over the plurality of firing events further identifies whether an actuator for an intake valve, an exhaust valve, or both, is degraded.

9. The method of claim 8 further comprising monitoring cylinder valve deactivation during a steady state of engine operation, the steady state of engine operation following a transition between activated and deactivated modes of cylinder operation.

10. The method of claim 9 wherein monitoring cylinder valve deactivation during the steady state of engine operation includes monitoring for the plurality of firing events over one complete engine cycle.

11. A method for monitoring cylinder valve deactivation in an engine, the engine including at least a cylinder valve actuator for deactivating at least a cylinder of the engine, the method comprising:

during a first condition, indicating degradation of the valve actuator based on crankshaft acceleration.

during a second condition, indicating degradation of the valve actuator based on at least one engine operating parameter.

12. The method of claim 11 wherein the engine operating parameter is selected from the group consisting of engine speed, manifold air pressure, crankshaft acceleration, and air charge.

13. A method for monitoring cylinder valve deactivation in an engine, the engine including a plurality of cylinders, a first valve actuator for deactivating an intake valve for at least one of the plurality of cylinders and a second valve actuator for deactivating an exhaust valve for at least one of the plurality of cylinders, the method comprising:

monitoring crankshaft acceleration to identify degradation in valve deactivation; and

identifying whether the degradation includes at least degradation of the first or second actuator based on the monitored crankshaft acceleration.

14. The method of claim 13, where the engine includes at least two banks of cylinders, the method further comprising:

when degradation is identified,

identifying a bank, and a valve type, based on the crankshaft acceleration pattern.

15. A method for detecting the operational status of a plurality of valves in a variable displacement internal combustion engine, the method comprising:

following a transition between operating modes of the variable displacement engine, measuring an engine crankshaft acceleration value for a plurality of firing events;

establishing a current crankshaft acceleration pattern based on measured crankshaft acceleration of the plurality of firing events; and

inferring an operational status of the valves responsive to the established current crankshaft acceleration pattern.

16. The method of claim 15 wherein establishing the current crankshaft pattern includes processing a crankshaft acceleration vector.

17. The method of claim 16 wherein inferring the operational status of the valves includes comparing the current crankshaft pattern with a predefined normal and a predefined degraded crankshaft acceleration pattern.

18. The method of claim 17 wherein comparing the current crankshaft pattern includes computing a distance between a first vector associated with the current crankshaft pattern with a second vector associated with the predefined normal and degraded crankshaft acceleration patterns.