CYLINDER HEAD ACCELERATION MEASUREMENT FOR VALVE TRAIN DIAGNOSTICS SYSTEM AND METHOD

• US 20160370254A1
• Filed: 06/22/2015
• Published: 12/22/2016
• Est. Priority Date: 06/22/2015
• Status: Active Grant

• Current Assignee: Ai Alpine Us Bidco LLC
• Original Assignee: General Electric Company
• Inventors: Rivellini, Sandro
• Granted Patent: US 9,933,334 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02D 41/009 using means for generating position or synchronisation signals
• CPC Class Codes: F02D 41/0097 using means for generating speed signals
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: G01M 15/05 by combined monitoring of two or more different engine parameters
• CPC Class Codes: G01M 15/06 by monitoring positions of pistons or cranks
• CPC Class Codes: G01M 15/11 by detecting misfire
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

In one embodiment, a system includes an engine control system configured to control an engine. The engine control system comprises a processor configured to receive a vibration signal sensed by a knock sensor disposed in an engine, and to receive a crankshaft signal sensed by a crank angle sensor disposed in the engine, wherein the crankshaft signal is representative of an engine crank angle. The processor is further configured to monitor a valve timing by deriving a cylinder head acceleration measurement via the vibration signal received by the knock sensor, wherein the processor is configured to monitor the valve timing by deriving a valve lash based on the vibration signal, the engine crank angle, and a threshold valve lash model.

Claims

1. A system comprising:

an engine control system configured to control an engine, wherein the engine control system comprises a processor configured to;

receive a vibration signal sensed by a knock sensor disposed in an engine;

receive a crankshaft signal sensed by a crank angle sensor disposed in the engine, wherein the crankshaft signal is representative of an engine crank angle; and

monitor a valve timing by deriving a cylinder head acceleration measurement via the vibration signal received by the knock sensor, wherein the processor is configured to monitor the valve timing by deriving a valve lash based on the vibration signal, the engine crank angle, and a threshold valve lash model.

2. The system of claim 1, wherein the threshold valve lash model comprises a graph having a valve lash measure disposed on an x-axis and a triggered crank angle measure disposed on a y-axis, wherein the valve lash measure is derived based on the vibration signal and the triggered crank angle measure is derived based on a crank angle sensor.

3. The system of claim 2, wherein the threshold valve lash model comprises a first quartile range, a third quartile range, and a median, wherein the threshold valve lash model comprises a statistical analysis of the cylinder head acceleration over a population of cycles representative of a continuous operation of the engine, and wherein the processor is configured to derive the valve lash by plotting a triggered crank angle via the y-axis to determine if the valve lash comprises a median quartile valve lash, first quartile valve lash, or third quartile valve lash.

4. The system of claim 1, wherein the processor is configured to derive a valve timing drift by applying the valve lash and a valve adjustment measure.

5. The system of claim 1, comprising deriving a maintenance condition based at least on the valve lash, wherein the maintenance condition comprises a valve lash consumption due to a cylinder head accelerated wear, a valve train component overexpansion, loose adjustment screw or a combination thereof.

6. The system of claim 1, wherein the processor is configured to derive a valve train condition by executing a valve timing change model.

7. The system of claim 6, wherein the valve timing change model comprises a graph having a valve timing drift on an y-axis and a valve lash measure on an x-axis, wherein the valve lash measures is derived based on the vibration signal.

8. The system of claim 7, wherein the valve train condition comprises a disengagement of a valve, and wherein the disengagement is derived by plotting the exhaust lash against the valve timing drift.

9. The system of claim 1, wherein the knock sensor comprises a Piezo-electric accelerometer, a microelectromechanical system (MEMS) sensor, a Hall effect sensor, a magnetostrictive sensor, or a combination thereof, and wherein the engine control system comprises an engine control unit (ECU) having the processor, wherein the knock sensor ECU is configured to detect an engine knock via the knock sensor.

10. A method, comprising:

sensing an engine vibration via a knock sensor;

sensing an engine crank angle via a crank angle sensor; and

monitoring a valve timing by deriving a cylinder head acceleration measurement via the engine vibration sensed by the knock sensor, wherein deriving cylinder head acceleration measurement comprises deriving a valve lash based on the sensed engine vibration, the engine crank angle, and a threshold valve lash model.

11. The method of claim 10, wherein the threshold valve lash model comprises a graph having a valve lash measure disposed on an x-axis and a crank angle measured disposed on a y-axis, wherein the valve lash measure is derived based on the vibration signal and the crank angle is derived based on a crank angle sensor.

12. The method of claim 11, comprising creating the threshold valve lash model by deriving a first natural frequency of the sensed engine vibration.

13. The method of claim 12, comprising creating the threshold valve lash model by analyzing a dynamic response of a valve seating about a cylinder head based on the natural frequency of the sensed engine vibration and a phase of the natural frequency.

14. The method of claim 13, comprising creating the threshold valve lash model by correlating the engine crank angle to the sensed engine vibration.

15. The method of claim 11 wherein the threshold valve lash model comprises a first quartile range, a third quartile range, and a median, wherein the threshold valve lash model comprises a statistical analysis of the cylinder head acceleration over a population of cycles representative of a continuous operation of the engine, and wherein the processor is configured to derive the valve lash by plotting a triggered crank angle via the y-axis to determine if the valve lash comprises a median quartile valve lash, first quartile valve lash, or third quartile valve lash.

16. A tangible, non-transitory computer readable medium storing code configured to cause a processor to:

receive a vibration signal sensed by a knock sensor disposed in an engine;

receive a crankshaft signal sensed by a crank angle sensor disposed in the engine, wherein the crankshaft signal is representative of an engine crank angle; and

monitor a valve timing by deriving a cylinder head acceleration measurement via the vibration signal received by the knock sensor, wherein the processor is configured to monitor the valve timing by deriving a valve lash based on the vibration signal, the engine crank angle, and a threshold valve lash model.

17. The computer readable medium of claim 16, wherein the threshold valve lash model comprises a graph having a valve lash measure disposed on an x-axis and a crank angle measured disposed on a y-axis, wherein the valve lash measure is derived based on the vibration signal and the crank angle is derived based on a crank angle sensor.

18. The computer readable medium of claim 17, comprising code configured to cause the processor to create the threshold valve lash model by deriving a first natural frequency of the sensed engine vibration.

19. The computer readable medium of claim 18, comprising code configured to cause the processor create the threshold valve lash model by analyzing a dynamic response of a valve seating about a cylinder head based on the natural frequency of the sensed engine vibration and a phase of the natural frequency, and by correlating the engine crank angle to the sensed engine vibration

20. The computer readable medium of claim 17, wherein the threshold valve lash model comprises a first quartile range, a third quartile range, and a median, wherein the threshold valve lash model comprises a statistical analysis of the cylinder head acceleration over a population of cycles representative of a continuous operation of the engine, and wherein the processor is configured to derive the valve lash by plotting a triggered crank angle via the y-axis to determine if the valve lash comprises a median quartile valve lash, first quartile valve lash, or third quartile valve lash.