Vehicle positioning system

1 . A vehicle positioning system, the system comprising:

a vehicle on a guideway;

processing circuitry in communication with the vehicle; and

a memory connected to the processing circuitry, wherein the memory is configured to store executable instructions that, when executed by the processing circuitry, facilitate performance of operations, comprising:

receive vehicle-speed data from a first set of sensors operably coupled to the vehicle;

predict a first-chain vehicle location based on the vehicle-speed data;

receive inertial data from a second set of sensors operably coupled to the vehicle;

update the predicted first-chain vehicle location based upon the inertial data;

predict a second-chain vehicle location based on the inertial data;

cross-check the predicted first-chain vehicle location against the predicted second-chain vehicle location, prior to updating the predicted first-chain vehicle location based upon the inertial data; and

update the predicted second-chain vehicle location based upon the vehicle-speed data.

2 . The system of claim 1 wherein the performance of operations further comprises:

update the predicted first and second-chain vehicle locations based on a vehicle path constraint stored in the memory, wherein the vehicle is restricted to travel on a parameterized three-dimensional (3D) vehicle path.

3 . The system of claim 2 wherein the performance of operations further comprises:

update the predicted first and second-chain vehicle locations based on a priori inertial landmarks along a vehicle path constraint and stored in the memory.

4 . The system of claim 3 wherein the performance of operations further comprises:

update the predicted first and second-chain vehicle locations based on other landmarks detected by a third set of sensors operably coupled to the vehicle and the a priori inertial landmarks along the vehicle path constraint and stored in the memory.

5 . The system of claim 4 wherein the performance of operations further comprises:

detection and isolation of fault conditions within one of the inertial data, the vehicle path constraint, the a priori inertial landmarks, and the other landmarks.

6 . The system of claim 5 wherein the performance of operations further comprises:

output a fault-updated vehicle location based on the fault conditions.

7 . The system of claim 1 wherein the performance of operations further comprises:

cross-check the predicted first-chain vehicle location against the predicted second-chain vehicle location, prior to updating the predicted second-chain vehicle location based upon the vehicle-speed data.

8 . A non-transitory computer-readable storage medium, comprising executable instructions that, when executed by a processor, facilitate performance of operations, comprising:

receiving vehicle-speed data from a first set of sensors operably coupled to a vehicle;

predicting a first-chain vehicle location based on the vehicle speed data;

receiving inertial data from a second set of sensors operably coupled to the vehicle;

updating the predicted first-chain vehicle location based upon the inertial data;

receiving the inertial data from the second set of sensors operably coupled to the vehicle;

predicting a second-chain vehicle location based on the inertial data; and

assigning a first weight to the predicted first-chain vehicle location or a second weight to the second-chain vehicle location based on cross-checking the predicted first-chain vehicle location and the predicted second-chain vehicle location.

9 . The storage medium of claim 8 wherein the performance of operations further comprises:

receiving the vehicle speed data from the first set of sensors operably coupled to the vehicle; and

updating the predicted second-chain vehicle location based upon the vehicle speed data.

10 . The storage medium of claim 9 wherein the performance of operations further comprises:

cross-checking the predicted first-chain vehicle location against the predicted second-chain vehicle location.

11 . The storage medium of claim 10 wherein the performance of operations further comprises:

determining whether one or more of the predicted first-chain vehicle location and the predicted second-chain vehicle location are unusable based upon the cross-check of the predicted first-chain vehicle location against the predicted second-chain vehicle location.

12 . The storage medium of claim 9 wherein the performance of operations further comprises:

cross-checking the updated first-chain vehicle location against the updated second-chain vehicle location.

13 . The storage medium of claim 12 wherein the performance of operations further comprises:

determining whether one or more of the updated first-chain vehicle location and the updated second-chain vehicle location are unusable based upon the cross-check of the updated first-chain vehicle location against the updated second-chain vehicle location.

14 . The storage medium of claim 9 wherein the performance of operations further comprises:

updating the updated first-chain vehicle location and the updated second-chain vehicle location based on detected faults in one of the first set of sensors and the second set of sensors.

15 . A method of positioning a vehicle comprising:

receiving vehicle speed data from a first set of sensors operably coupled to a vehicle;

receiving vehicle inertial data from a second set of sensors operably coupled to the vehicle;

predicting a first vehicle location with processing circuitry and based on the vehicle speed data;

predicting a second vehicle location with the processing circuitry and based on the vehicle inertial data;

cross-checking the first predicted vehicle location against the second predicted vehicle location prior to updating the predicted first-chain vehicle location based upon the inertial data; and

determining whether one of the predicted first vehicle location and the predicted second vehicle location is unreliable based upon the cross-checking.

16 . The method of claim 15 further comprising, after cross-checking the first predicted vehicle location against the second predicted vehicle location:

updating the predicted first vehicle location based upon the vehicle inertial data;

updating the predicted second vehicle location based upon the vehicle speed data; and

cross-checking the first updated vehicle location against the second updated vehicle location.

17 . The method of claim 16 further comprising:

determining whether one or more of the updated first vehicle location and the updated second vehicle location is unreliable based upon the cross-check of the updated first vehicle location against the updated second vehicle location.

18 . The method of claim 17 further comprising:

updating one or more of the predicted first vehicle location and the predicted second vehicle location based upon a constrained vehicle path that the vehicle is traveling.

19 . The method of claim 17 further comprising:

updating one or more of the predicted first vehicle location and the predicted second vehicle location based upon inertial landmarks stored in a memory.

20 . The method of claim 19 further comprising,

updating one or more of the predicted first vehicle location and the predicted second vehicle location based upon other landmarks stored in the memory.