Ternary sensor inputs

• US 8,204,712 B2
• Filed: 10/07/2008
• Issued: 06/19/2012
• Est. Priority Date: 10/07/2008
• Status: Active Grant

• Current Assignee: Eaton Cummins Automated Transmission Technologies, LLC
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Katrak, Kerfegar Khurshed
• Primary Examiner(s): WACHSMAN, HAL D
• Application Number:
  US12/247,067
• Publication Number:
  US 20100085082A1
• Time in Patent Office: 1,351 Days
• Field of Search: 702/150, 702/58, 702/59, 702/113, 702/114, 702/185
• US Class Current: 702/150
• CPC Class Codes: F16H 2061/122 Avoiding failures by using redundant parts
• CPC Class Codes: F16H 2061/1284 the failing part is a sensor
• CPC Class Codes: F16H 59/0217 with electric switches or sensors not for gear or range selection, e.g. for controlling auxiliary devices for gear selection F16H59/044; for range selection F16H59/105
• 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: G01D 5/24457 Failure detection
• CPC Class Codes: G01D 5/2497 Absolute encoders G01D5/2454 takes precedence
• CPC Class Codes: H03K 17/9512 using digital techniques
• CPC Class Codes: H03K 17/965 Switches controlled by moving an element forming part of the switch
• CPC Class Codes: H03K 2017/9713 Multiposition, e.g. involving comparison with different thresholds
• CPC Class Codes: H03K 2217/94052 with evaluation of actuation pattern or sequence, e.g. tapping
• CPC Class Codes: H03K 2217/9658 Safety, e.g. fail-safe switching requiring a sequence of movements
• CPC Class Codes: H03K 5/19 Monitoring patterns of pulse trains indicating amplitude G01R19/00; indicating frequency G01R23/00; measuring characteristics of individual pulses G01R29/02

Abstract

One of a first signal, a second signal, and a third signal is received respectively from each of three inputs. A pattern formed by the first signal, the second signal, and the third signal is compared to a set of predetermined patterns. Based on the comparing, it is determined whether an error exists. If an error condition exists, a specific one of the inputs is identified as a cause of the error.

Claims

1. A method, comprising:

receiving one of a first signal, a second signal, and a third signal respectively from each of three inputs;

comparing a pattern of states formed by the first signal, the second signal, and the third signal to a set of predetermined patterns;

determining whether an error condition exists based on whether an error condition is indicated by one or more patterns identified from the set of predetermined patterns; and

if an error condition exists, identifying a specific one of the inputs as a cause of the error based at least in part on the pattern or patterns identified from the set of predetermined patterns.

2. The method of claim 1, further comprising determining, based on the one or more identified patterns, an expected position of a physical member.

3. The method of claim 2, wherein the physical member is a shift lever in a vehicle.

4. The method of claim 2, further comprising:

receiving one of a fourth signal, a fifth signal, and a sixth signal from each of the three inputs;

comparing a second pattern of states formed by each of the fourth signal, the fifth signal, and the sixth signal to the set of predetermined patterns;

based on a second one or more of the identified patterns indicated by the comparing of the second pattern, determining a second expected position of the physical member.

5. The method of claim 4, wherein the pattern and the second pattern have a Hamming distance of at least two between them.

6. The method of claim 1, wherein the first signal, the second signal, and the third signal are each associated with one of a first asserted state, a second asserted state, and a default state.

7. The method of claim 6, further comprising determining that the input that is a cause of the error is providing a signal associated with one of the first asserted state, the second asserted state, and the default state.

8. The method of claim 6, wherein one of the first asserted state, the second asserted state and the default state represent an error condition.

9. The method of claim 1, wherein the set of predetermined patterns is stored in a table.

10. The method of claim 1, wherein the error is one of a make after break failure, a short to ground condition, a short to battery condition, and an open condition.

11. A method, comprising:

receiving one of a first signal, a second signal, and a third signal from each of three inputs;

comparing a first pattern of states formed by the first signal, the second signal, and the third signal to a set of predetermined patterns;

based on the comparing of the first pattern, determining an expected detent position of a physical member;

receiving one of a fourth signal, a fifth signal, and a sixth signal;

comparing a second pattern of states formed by the fourth signal, a fifth signal, and a sixth signal to the set of predetermined patterns;

based on the comparing of the second pattern, determining a second expected detent position of a physical member;

wherein the first pattern and the second pattern are separated by a Hamming distance of at least two.

12. The method of claim 11, further comprising determining whether an error condition exists based on whether an error condition is indicated by one or more patterns included in the set of predetermined patterns, and identified by at least one of the comparing of the first pattern and the comparing of the second pattern, and, if an error condition does exist, identifying a specific one of the inputs that is a cause of the error.

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

receiving one of a first signal, a second signal, and a third signal respectively from each of three inputs;

comparing a pattern of states formed by the first signal, the second signal, and the third signal to a set of predetermined patterns;

determining whether an error condition exists based on whether an error condition is indicated by one or more patterns identified by the comparing from the set of predetermined patterns; and

if an error condition exists, identifying a specific one of the inputs as a cause of the error based at least in part on the pattern or patterns identified by the comparing.

14. The non-transitory computer-readable medium of claim 13, the instructions further comprising instructions for determining, based on the comparing, an expected position of a physical member.

15. The non-transitory computer-readable medium of claim 14, wherein the physical member is a shift lever in a vehicle.

16. The non-transitory computer-readable medium of claim 14, the instructions further comprising instructions for:

receiving one of a fourth signal, a fifth signal, and a sixth signal from each of the three inputs;

comparing a second pattern of states formed by each of the fourth signal, the fifth signal, and the sixth signal to the set of predetermined patterns;

based on a second one or more of the identified patterns indicated by the comparing of the second pattern, determining a second expected position of the physical member.

17. The non-transitory computer-readable medium of claim 16, wherein the pattern and the second pattern have a Hamming distance of at least two between them.

18. The non-transitory computer-readable medium of claim 14, wherein the first signal, the second signal, and the third signal are each associated with one of a first asserted state, a second asserted state, and a default state.

19. The non-transitory computer-readable medium of claim 18, the instructions further comprising instructions for determining that the input that is a cause of the error is providing a signal associated with one of the first asserted state, the second asserted state, and the default state.

20. The non-transitory computer-readable medium of claim 18, wherein one of the first asserted state, the second asserted state and the default state represent an error condition.

21. The non-transitory computer-readable medium of claim 13, wherein the set of predetermined patterns is stored in a table.

22. The non-transitory computer-readable medium of claim 13, wherein the error is one of a make after break failure, a short to ground condition, a short to battery condition, and an open condition.

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

receiving one of a first signal, a second signal, and a third signal from each of three inputs;

comparing a first pattern of states formed by the first signal, the second signal, and the third signal to a set of predetermined patterns;

based on the comparing of the first pattern, determining an expected detent position of a physical member;

receiving one of a fourth signal, a fifth signal, and a sixth signal;

comparing a second pattern of states formed by the fourth signal, a fifth signal, and a sixth signal to the set of predetermined patterns;

based on the comparing of the second pattern, determining a second expected detent position of a physical member;

wherein the first pattern and the second pattern are separated by a Hamming distance of at least two.

24. The non-transitory computer-readable medium of claim 23, the instructions further comprising instructions for determining whether an error condition exists based on whether an error condition is indicated by one or more patterns included in the set of predetermined patterns, and identified by at least one of the comparing of the first pattern and the comparing of the second pattern, and, if an error condition does exist, identifying a specific one of the inputs that is a cause of the error.