Shift rail transmission position sensing

1. A device for monitoring a transmission, comprising:

a first sensor;

a second sensor; and

a control unit, wherein the control unit is configured to:

receive sensor data related to position of a first gear in the transmission, the sensor data including data from the first sensor and data from the second sensor;

determine a first indicated position of the first gear from the data from the first sensor;

determine a second indicated position of the first gear from the data from the second sensor;

compare the first indicated position to the second indicated position;

determine based on the comparison a gear engagement status of the gear

wherein the first sensor and the second sensor are attached to a first shift rail in a shift rail transmission,

wherein the transmission includes a plurality of gears including the first gear, and wherein the first shift rail moves a gear engagement element to selectively engage the first gear at a first end of a first shift rail travel path or to engage a second gear of the plurality of gears at a second end of the first shift rail travel path,

wherein the first sensor is situated to indicate engagement of the first gear and the second sensor is situated to indicate engagement of the second gear, and

wherein the control unit is further configured to:

detect engagement of the first gear by using data from the second sensor as cross-check information for cross-checking the first indicated position determined from the data from the first sensor; and

detect engagement of the second gear by using the data from the first sensor as cross-check information for cross-checking the second indicated position determined from the data from the second sensor.

2. The device of claim 1 , wherein the first sensor and the second sensor are Hall Effect sensors that generate an output when passing through a magnetic field and wherein the output is indicative of field strength and varies according to proximity of the sensors to magnets attached to the transmission.

3. The device of claim 2 , wherein each of said magnets is attached to a steel plate.

4. The device of claim 2 , wherein said magnets include two magnets attached to the transmission with opposite orientations of their respective poles.

5. The device of claim 1 , wherein the first and second sensors each provide an indication that the shift rail is entering or is in a neutral position, and the information from each sensor is used to cross-check the information from the other sensor.

6. The device of claim 1 , wherein the transmission is a double-clutch transmission and wherein the first gear is disengaged at substantially the same time as the second gear is engaged.

7. The device of claim 1 , wherein the first shift rail one of a plurality of shift rails in a double-clutch transmission, and wherein a second shift rail of the plurality of shift rails selectively engages a third or a fourth gear, and wherein the first shift rail moves to disengage the first gear at substantially the same time as the second shift rail moves to engage the fourth gear.

8. The device of claim 1 , further comprising:

a plurality of primary sensors, including the first sensor, in a shift rail transmission including a plurality of shift rails;

wherein each of the plurality of primary sensors is attached to a separate one of the plurality of shift rails in a one-to-one correspondence; and

wherein each of the plurality of primary sensors is configured to provide data indicating that the corresponding shift rail is in or is transitioning to one of multiple positions.

9. The device of claim 8 , wherein there are three positions of a shift rail and the positions represent: engagement of a first gear in mechanical communication with the shift rail; engagement of a second gear in mechanical communication with the shift rail; and a neutral position in which the first gear and the second gear are disengaged.

10. The device of claim 8 , wherein the second sensor is a transmission speed sensor.

11. A non-transitory computer readable medium, having instructions tangibly embodied thereon, the instructions being executable by a processor to cause the processor to perform operations comprising:

receiving sensor data related to position of a gear in a transmission, the sensor data including data from a first sensor and data from a second sensor;

determining a first indicated position of the gear from the data from the first sensor;

determining a second indicated position of the gear from the data from the second sensor;

comparing the first indicated position to the second indicated position;

determining based on the comparison a gear engagement status of the gear

wherein the first sensor and the second sensor are attached to a shift rail in a shift rail transmission, and

wherein the first sensor is situated to indicate engagement of the first gear and the second sensor is situated to indicate engagement of the second gear, and wherein the first sensor provides cross-check information regarding gear engagement of the second gear, and the second sensor provides cross-check information regarding gear engagement of the first gear.

12. The computer readable medium of claim 11 , wherein the first sensor and the second sensor are Hall Effect sensors that generate an output when passing through a magnetic field and wherein the output is indicative of field strength and varies according to proximity of the sensors to magnets attached to the transmission.

13. The computer readable medium of claim 12 , wherein each of said magnets is attached to a steel plate, and wherein said magnets include two magnets attached to the transmission with opposite orientations of their respective poles.

14. The computer readable medium of claim 12 , wherein the first and second sensors each provide an indication that the shift rail is entering or is in a neutral position, and the information from each sensor is used to cross-check the information from the other sensor.

15. The computer readable medium of claim 11 , wherein the gear is a first gear of a plurality of gears, and wherein the shift rail moves a gear engagement element to selectively engage the first gear at a first end of the shift rail travel path or to engage a second gear of the plurality of gears at a second end of the shift rail travel path.

16. The computer readable medium of claim 11 , wherein the transmission is a double-clutch transmission and wherein the first gear is disengaged at substantially the same time as the second gear is engaged.

17. The computer readable medium of claim 11 , wherein the shift rail is a first rail of a plurality of shift rails in a double-clutch transmission, and wherein a second shift rail of the plurality of shift rails selectively engages a third or a fourth gear, and wherein the first shift rail moves to disengage the first gear at substantially the same time as the second shift rail moves to engage the fourth gear.