| 摘要 |
PURPOSE:To allow an operator to devote to other work and to reduce the working restriction of a vehicle, by automatically performing the renewal of a zero speed or re-alignment when the stop time of the vehicle is a predetermined time or more. CONSTITUTION:A stop/movement detection means 70 constituted of a car speedometer 60 detects the stoppage ore movement of a vehicle and a position error calculation part 53 calculates the error of the data, which is obtained from a position calculation part 52 from the data, which is obtained from a speed calculation part 51, during the stoppage of the vehicle on the basis of the output of the detection means 70. A control part 90 detects whether the stop time of the vehicle is a predetermined time or more from the output of the detection means 70. When the stop time is the predetermined time or more, the data from the speed calculation part 51 is renewed to zero as well as the data from the position calculation part 52 is renewed on the basis of the data from the position error calculation part 53 after a predetermined time is elapsed from the point of time when the vehicle is stopped or when the vehicle is moved. When the stop time is below the predetermined time, no renewal is performed and, when the vehicle is moved, the speed calculation part 51 and the position calculation part 52 are allowed to continued the calculation of a speed and that of a position. |
