A POSITIONING SYSTEM AND METHOD

摘要

593023 A positioning method includes calculating a lower accuracy positioning solution. An offset to the lower accuracy positioning solution is applied to form a final positioning solution if a higher accuracy positioning solution is unavailable. The offset is representative of a difference between the lower accuracy positioning solution and the higher accuracy positioning solution at a point in time when the higher accuracy positioning solution was last available. A positioning method includes continuously determining whether the higher accuracy positioning solution has again become available; and in the event that the higher accuracy positioning solution has become available; calculating the higher accuracy positioning solution; applying a reacquisition offset to the higher accuracy positioning solution to form an adjusted higher accuracy positioning solution; and setting the adjusted higher accuracy position solution as a new final positioning solution. A positioning system and method for a vehicle are disclosed. The positioning system comprises a higher accuracy positioning module (1331) configured to calculate a higher accuracy positioning solution (line 4000) for the vehicle; a lower accuracy positioning module (1332) configured to calculate a lower accuracy positioning solution (line 5000) for the vehicle; and a correction module (1333) in communication with the higher accuracy positioning module and the lower accuracy positioning module. The correction module is configured to provide a final positioning solution (13334) to guide the vehicle along a predetermined path. The correction module is further configured to maintain an offset representative (L) of the difference between the higher accuracy positioning solution and the lower accuracy positioning solution whilst the higher accuracy positioning solution is reliable; apply the offset to the lower accuracy positioning solution to form the final positioning solution in the event that that higher accuracy positioning solution becomes unreliable; and applying a reacquisition offset to the higher accuracy positioning solution to form an adjusted higher accuracy positioning solution if the higher accuracy positioning solution was determined to be unreliable but has again been determined to be reliable.