Discrete sensor inputs

• US 8,044,787 B2
• Filed: 10/07/2008
• Issued: 10/25/2011
• Est. Priority Date: 10/07/2008
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Zuppann, Richard Earl, Katrak, Kerfegar Khurshed, Fritz, Todd William
• Primary Examiner(s): Mehmood; Jennifer
• Application Number:
  US12/247,016
• Publication Number:
  US 20100085178A1
• Time in Patent Office: 1,113 Days
• Field of Search: 340/438, 340/439, 340/453, 340/454, 340/456, 340/686.1, 340/691.7, 340/691.8, 340/3.43, 340/3.44, 341/97, 341/106, 341/94, 477/906, 714 48- 52, 714/57
• US Class Current: 340/456
• CPC Class Codes: F16H 59/105 consisting of electrical switches or sensors
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: Y10S 477/906 Means detecting or ameliorating the effects of malfunction or potential malfunction

Abstract

A set of inputs each selectively provides a discrete signal, whereby the sensor inputs together provide a plurality of discrete signals. A memory includes instructions executable by a processor for receiving the discrete signals, identifying a bit pattern from the discrete signals, and determining a position of a physical member according to the bit pattern and an error condition detected from the discrete signals.

Claims

1. A method, comprising:

detecting a plurality of discrete signals, each of the discrete signals being received from a respective one of a plurality of inputs;

identifying a detected bit pattern based on the discrete signals;

detecting selectively an error condition, and identifying the error condition as one of at least one of a short to battery condition, a short to ground condition, and a failure of a make after break feature, according to the bit pattern; and

determining an expected position of a physical member according to the bit pattern;

wherein the make after break feature fails if one of the inputs that was in a high asserted state fails to break to a low or non-asserted state when the physical member moves from a first detent position to a second detent position.

2. The method of claim 1, wherein the physical member is a shift lever for an automatic transmission in a vehicle.

3. The method of claim 1, further comprising transmitting an instruction based on the position of the physical member.

4. The method of claim 1, further comprising determining a plurality of possible bit patterns, each of the possible bit patterns being a bit pattern for a possible combination of the discrete signals, and identifying the detected bit pattern by matching it to one of the possible bit patterns.

5. The method of claim 4, further comprising using a Karnaugh map for determining the plurality of possible bit patterns.

6. The method of claim 5, further comprising associating states in the Karnaugh map having a majority of bits being ones with combinations of the discrete signals that have been deemed to be more important than other combinations of the discrete signals.

7. The method of claim 6, wherein the combinations of the discrete signals that have been deemed to be more important are associated with detent positions of the physical member.

8. The method of claim 1, wherein the bit pattern is a combination of high asserted states.

9. The method of claim 1, further comprising:

detecting a second plurality of discrete signals, each of the second plurality of the discrete signals being received from a respective one of the inputs;

identifying a second detected bit pattern based on the second plurality of discrete signals;

determining whether an error condition exists according to the bit pattern;

if an error condition exists, considering whether the error condition warrants a fail-safe mode, considering whether the error condition warrants a fail-soft mode, and determining whether the error condition warrants one of the fail-safe mode and the fail-soft mode, and entering one of the fail-safe mode and the fail-soft mode based on the determination; and

if no error condition exists, or if no fail-safe mode applies, determining a second position of the physical member according to the second detected bit pattern.

22. The method of claim 1, further comprising identifying a specific one of the inputs as being responsible for the error condition.

10. A system, comprising:

a set of sensors providing inputs that each selectively provide a discrete signal, whereby the sensor inputs together provide a plurality of discrete signals;

a processor; and

a memory including instructions executable by the processor for;

receiving the discrete signals,

determining a bit pattern from the discrete signals,

detecting selectively an error condition, and identifying the error condition as one of at least one of a short to battery condition, a short to ground condition, and a failure of a make after break feature, according to the bit pattern,

and identifying a position of a physical member according to the bit pattern;

wherein the make after break feature fails if one of the inputs that was in a high asserted state fails to break to a low or non-asserted state when the physical member moves from a first detent position to a second detent position.

11. The system of claim 10, wherein the physical member is a shift lever, the system further comprising a vehicle that includes the shift lever.

12. The system of claim 10, the instructions further including instructions for transmitting an instruction based on the position of the physical member.

13. A computer-readable medium tangibly embodying instructions executable by a processor, the instructions comprising instructions for:

detecting a plurality of discrete signals, each of the discrete signals being received from a respective one of a plurality of inputs;

identifying a detected bit pattern based on the discrete signals;

detecting selectively an error condition, and identifying the error condition as one of at least one of a short to battery condition, a short to ground condition, and a failure of a make after break feature, according to the bit pattern; and

determining an expected position of a physical member according to the bit pattern;

wherein the make after break feature fails if one of the inputs that was in a high asserted state fails to break to a low or non-asserted state when the physical member moves from a first detent position to a second detent position.

14. The medium of claim 13, wherein the physical member is a shift lever for an automatic transmission in a vehicle.

15. The medium of claim 13, the instructions further comprising instructions for transmitting an instruction based on the position of the physical member.

16. The medium of claim 13, the instructions further comprising instructions for determining a plurality of possible bit patterns, each of the possible bit patterns being a bit pattern for a possible combination of the discrete signals, and identifying the detected bit pattern by matching it to one of the possible bit patterns.

17. The medium of claim 16, the instructions further comprising instructions for further comprising using a Karnaugh map for determining the plurality of possible bit patterns.

18. The medium of claim 17, the instructions further comprising instructions for associating states in the Karnaugh map having a majority of bits being ones with combinations of the discrete signals that have been deemed to be more important than other combinations of the discrete signals.

19. The medium of claim 18, wherein the combinations of the discrete signals that have been deemed to be more important are associated with detent positions of the physical member.

20. The medium of claim 13, wherein the bit pattern is a combination of high asserted states.

21. The medium of claim 13, the instructions further comprising instructions for:

detecting a second plurality of discrete signals, each of the second plurality of the discrete signals being received from a respective one of the inputs;

identifying a second detected bit pattern based on the second plurality of discrete signals;

determining whether an error condition exists according to the bit pattern;

if an error condition exists, considering whether the error condition warrants a fail-safe mode, considering whether the error condition warrants a fail-soft mode, and determining whether the error condition warrants one of the fail-safe mode and the fail-soft mode, and entering one of the fail-safe mode and the fail-soft mode based on the determination; and

if no error condition exists, or if no fail-safe mode applies, determining a second position of the physical member according to the second detected bit pattern.

23. The medium of claim 13, the instructions for comprising instructions for identifying a specific one of the inputs as being responsible for the error condition.