Granted Patent B2

US 7,844,376 · App. 11/468,029 · Granted Nov 30, 2010

Abstract

Claims (38)

1. A method for determining a position of a range indication device for an automatic transmission, comprising:

receiving N bits corresponding to a state of N circuits, respectively, wherein said N bits are related to a position of said range indication device,

wherein said position includes transmission range states and a transitional state between said transmission range states;

defining a bit pattern for each of said transitional state and said transmission range states;

wherein N bits of said bit pattern are set equal to a first state for said transitional state; and

wherein N/2 bits of said bit pattern are equal to said first state and N/2 other bits of said bit pattern are equal to a second state for said transmission range states, where N is an even integer greater than one.

2. The method of claim 1 further comprising diagnosing a fault in the range indication device when said bit pattern is not defined as said transitional state and is not defined as one of said transmission range states.

3. The method of claim 1 wherein said transmission range states include park, reverse, neutral, drive 6 , drive 4 , drive 3 , and drive 2 .

4. The method of claim 1 wherein said N circuits have one of an open state and a closed state.

5. The method of claim 4 wherein said bit pattern includes at least one of zeros and ones, and wherein a zero bit of said bit pattern indicates an open state and a one bit of said bit pattern indicates a closed state.

6. The method of claim 4 wherein said bit pattern includes a plurality of at least one of zeros and ones, and wherein a zero of said bit pattern indicates a closed state and a one of said bit pattern indicates an open state.

7. A range indication device for indicating at least one of a range state and a transitional state to an automatic transmission control system, comprising:

a housing including N tracks each with conductive and non-conductive material;

a sliding mechanism that includes N contacts that align with said N tracks to form N circuits,

wherein said sliding mechanism slides to M transitional positions and X range positions, and

wherein said N circuits can be in at least one of a first state and a second state; and

N signal generating devices that generate N signals based on states of said N circuits, respectively,

wherein said conductive material is positioned in said N tracks such that each of said N circuits are in said first state when said sliding mechanism is in each of said M transitional positions, and wherein N, M and X are integers.

8. The range indication device of claim 7 wherein said conductive material is positioned in said N tracks such that N/2 circuits of said N circuits are in said first state and N/2 other circuits of said N circuits are in said second state when said sliding mechanism is in said X range positions.

9. The range indication device of claim 8 wherein said first state corresponds to an open state of said N circuits and wherein said second state corresponds to a closed state of said N circuits.

10. The range indication device of claim 8 wherein said first state corresponds to a closed state of said N circuits and wherein said second state corresponds to an open state of said N circuits.

11. The range indication device of claim 10 wherein said N signal generating devices generate at least one of a high signal and a low signal, and wherein a high signal corresponds to an open state of a corresponding one of said N circuits and a low signal corresponds to a closed state of a corresponding one of said N circuits.

12. The range indication device of claim 7 wherein X is equal to seven and said X range positions are park, reverse, neutral, drive 6 , drive 4 , drive 3 , and drive 2 .

13. The range indication device of claim 7 wherein said conductive tracks are positioned such that Z circuits of said N circuits are in one of said first state and said second state when a short of one circuit of said N circuits occurs and wherein Z is an odd integer less than N.

14. The range indication device of claim 7 wherein said M transitional positions are positions between said X range positions.

15. A fault detection system for a range indication device, comprising:

a signal input device that receives a signal indicating states of N circuits within the range indication device; and

a control module that receives said signal via said signal input device, assembles said signal into a bit pattern, and associates said bit pattern with at least one of a transitional state, a range state, and an illegal state,

wherein when said bit pattern is associated with said illegal state, a fault is detected, and

wherein:

when said bit pattern indicates N circuits are in a first state, said bit pattern is associated with said transitional state,

when said bit pattern indicates N/2 circuits of said N circuits are in said first state and N/2 other circuits of said N circuits are in a second state, said bit pattern is associated with said range state, and

otherwise said bit pattern is associated with said illegal state.

16. The fault detection system of claim 15 wherein said range state of the range indication device can be at least one of park, reverse, neutral, drive 6 , drive 4 , drive 3 , and drive 2 .

17. The fault detection system of claim 15 wherein said states of said N circuits are at least one of an open state and a closed state.

18. The fault detection system of claim 17 wherein said bit pattern includes a zero for said closed state and a one for said open state.

19. The fault detection system of claim 18 wherein said bit pattern includes a one for said open state and a zero for said closed state.

20. The fault detection system of claim 15 wherein said transitional state is a state between range states of the range indication device.

Assignments (12)