TERNARY SENSOR INPUTS

• US 20100085082A1
• Filed: 10/07/2008
• Published: 04/08/2010
• 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 K.
• Granted Patent: US 8,204,712 B2
• Time in Patent Office: Days
• US Class Current: 327/20
• 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 formed by the first signal, the second signal, and the third signal to a set of predetermined patterns;

based on the comparing, determining whether an error exists; and

if an error condition exists, identifying a specific one of the inputs as a cause of the error.

2. The method of claim 1, further comprising determining, based on the comparing, 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 formed by each of the fourth signal, the fifth signal, and the sixth signal to the set of predetermined patterns;

based on the comparing, 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 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 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, based on at least one of the comparing of the first pattern and the comparing of the second pattern, determining whether an error exists, and, if an error does exist, identifying a specific one of the inputs that is a cause of the error.

13. A 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 formed by the first signal, the second signal, and the third signal to a set of predetermined patterns;

based on the comparing, determining whether an error exists; and

if an error condition exists, identifying a specific one of the inputs as a cause of the error.

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

15. The medium of claim 14, wherein the physical member is a shift lever in a vehicle.

16. The 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 formed by each of the fourth signal, the fifth signal, and the sixth signal to the set of predetermined patterns;

based on the comparing, determining a second expected position of the physical member.

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

18. The 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 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 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 medium of claim 13, wherein the set of predetermined patterns is stored in a table.

22. The 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 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 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 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 medium of claim 23, the instructions further comprising instructions for, based on at least one of the comparing of the first pattern and the comparing of the second pattern, determining whether an error exists, and, if an error does exist, identifying a specific one of the inputs that is a cause of the error.