POSITION MEASURING SYSTEM

PROBLEM TO BE SOLVED: To provide a position measuring system correcting position information accurately with a simple facility constitution. SOLUTION: In this position measuring system 1, a moving body 2 is loaded with a displacement sensor 34 for measuring displacement of a rail, a range finder 31 for measuring a position, and a data processing device 4. The data processing device 4 in the position measuring system 1 includes a rail joint gap position management DB 43 having position information of each rail joint gap 9 registered therein. A control part 41 of the data processing device 4 monitors measurement data of the displacement sensor 34 and measurement position data of the range finder 31. The control part 41 extracts measurement position data when the measurement data of the displacement sensor 34 show characteristic data which are peculiar to the rail joint gap 9, or rail joint gap position information existing in the periphery thereof from the rail joint gap position management DB 43, and holds it as a prediction value. Then, the control part 41 collates measurement position data by the range finder 31 with the extracted prediction value, and corrects the measured distance to the prediction value (registered rail joint gap position information) in the case of disagreement. COPYRIGHT: (C)2011,JPO&INPIT