Valvetrain fault indication systems and methods using knock sensing

• US 9,121,362 B2
• Filed: 08/21/2012
• Issued: 09/01/2015
• Est. Priority Date: 08/21/2012
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Betz, Brian E., Miller, Hugh William
• Primary Examiner(s): Cronin, Stephen K
• Assistant Examiner(s): Scharpf, Susan E
• Application Number:
  US13/590,351
• Publication Number:
  US 20140058650A1
• Time in Patent Office: 1,106 Days
• Field of Search: 701/111, 701/102, 701/103, 701/105, 701/29.1, 701/29.7, 701/30.3, 701/30.5, 701/30.6, 701/31.7, 123/90.16
• US Class Current: 1/1
• CPC Class Codes: F01L 13/0031 by modification of tappet or pushrod length
• CPC Class Codes: F01L 13/0036 the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
• CPC Class Codes: F01L 2820/04 Sensors
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: F02P 5/1521 with particular means during a transient phase, e.g. starting, acceleration, deceleration, gear change
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system for a vehicle includes a knock indication module, a valve control module, and a fault indication module. The knock indication module selectively indicates that knock occurred within a cylinder of an engine. The valve control module controls lifting of a valve of a cylinder of the engine and, in response to the knock indication module indicating that knock occurred within the cylinder, transitions lifting of the valve from one of a low lift state and a high lift state to the other one of the low lift state and the high lift state. The fault indication module selectively indicates that a fault is present in a variable valve lift (VVL) mechanism of the cylinder based on whether the knock indication module indicates that knock occurred within the cylinder after the transition to the other one of the low lift state and the high lift state.

Claims

1. A system for a vehicle, comprising:

a first electronic circuit that selectively indicates that knock occurred within a cylinder of an engine;

a second electronic circuit that controls lifting of a valve of the cylinder of the engine and that, in response to the first electronic circuit indicating that knock occurred within the cylinder, transitions lifting of the valve from one of a low lift state and a high lift state to the other one of the low lift state and the high lift state; and

a third electronic circuit that indicates that a fault is present in a variable valve lift (VVL) mechanism of the cylinder when the first electronic circuit does not indicate that knock occurred within the cylinder after the transition to the other one of the low lift state and the high lift state.

2. The system of claim 1 wherein the third electronic circuit further indicates that the valve is stuck operating in the one of the low lift state and the high lift state when the first electronic circuit does not indicate that knock occurred within the cylinder after the transition to the other one of the low lift state and the high lift state.

3. The system of claim 1 wherein the third electronic circuit further indicates that the fault is associated with the cylinder when the first electronic circuit does not indicate that knock occurred within the cylinder after the transition to the other one of the low lift state and the high lift state.

4. The system of claim 1 wherein the third electronic circuit indicates that the fault is not present in the VVL mechanism when the first electronic circuit indicates that knock occurred within the cylinder after the transition to the other one of the low lift state and the high lift state.

5. The system of claim 1 wherein the third electronic circuit indicates whether knock occurred within the cylinder based on a knock signal from a piezo-electric knock sensor.

6. The system of claim 1 wherein the third electronic circuit sets a predetermined diagnostic trouble code (DTC) in memory when a fault is present in the VVL mechanism.

7. The system of claim 6 further comprising a fourth electronic circuit that monitors the memory and that illuminates a malfunction indicator lamp in response to the setting of the predetermined DTC.

8. The system of claim 1 further comprising a fourth electronic circuit that selectively advances spark timing of the cylinder in response to the first electronic circuit indicating that knock occurred within the cylinder.

9. The system of claim 8 wherein the fourth electronic circuit advances the spark timing of the cylinder past a maximum best torque (MBT) spark timing in response to the knock indication module indicating that knock occurred within the cylinder.

10. The system of claim 1 wherein the first, second, and third electronic circuits include or are a part of at least one of:

an Application Specific Integrated Circuit (ASIC);

a combinational logic circuit;

a field programmable gate array (FPGA); and

a processor, memory, and code.

11. A method for a vehicle, comprising:

selectively indicating that knock occurred within a cylinder of an engine;

controlling lifting of a valve of a cylinder of the engine;

in response to an indication that knock occurred within the cylinder, transitioning lifting of the valve from one of a low lift state and a high lift state to the other one of the low lift state and the high lift state; and

indicating that a fault is present in a variable valve lift (VVL) mechanism of the cylinder in response to an indication that knock did not occur within the cylinder after the transition to the other one of the low lift state and the high lift state.

12. The method of claim 11 further comprising indicating that the valve is stuck operating in the one of the low lift state and the high lift state in response to the indication that knock did not occur within the cylinder after the transition to the other one of the low lift state and the high lift state.

13. The method of claim 11 further comprising indicating that a fault is associated with the cylinder in response to the indication that knock did not occur within the cylinder after the transition to the other one of the low lift state and the high lift state.

14. The method of claim 11 further comprising indicating that a fault is not present in the VVL mechanism in response to a second indication that knock occurred within the cylinder after the transition to the other one of the low lift state and the high lift state.

15. The method of claim 11 further comprising indicating whether knock occurred within the cylinder based on a knock signal from a piezo-electric knock sensor.

16. The method of claim 11 further comprising setting a predetermined diagnostic trouble code (DTC) in memory when a fault is present in the VVL mechanism.

17. The method of claim 16 further comprising:

monitoring the memory; and

illuminating a malfunction indicator lamp in response to the setting of the predetermined DTC.

18. The method of claim 11 further comprising selectively advancing spark timing of the cylinder in response to the indication that knock occurred within the cylinder.

19. The method of claim 18 further comprising advancing the spark timing of the cylinder past a maximum best torque (MBT) spark timing in response to the indication that knock occurred within the cylinder.