MOVEMENT-DISTANCE MEASUREMENT APPARATUS CAPABLE OF REDUCING ERROR DUE TO CHANGE IN ANGLE OF MAXIMUM REFLECTION INTENSITY ACCORDING TO MOVEMENT AND REDUCING ERROR DUE TO MISALIGNMENT OF ANTENNA

摘要

A movement-distance measuring apparatus is provided with: an antenna, a phase detection circuit, a phase-shift calculation circuit, and a movement-distance calculation circuit. The antenna transmits a radio wave toward a plurality of reflectors arranged at constant intervals along a moving path of a moving object, and receives a reflected wave from the reflectors. The phase detection circuit detects a phase of the reflected wave received by the antenna. The phase-shift calculation circuit calculates a phase shift based on the phase detected by the phase detection circuit. The movement-distance calculation circuit calculates a movement distance of the moving object, based on the phase shift calculated by the phase-shift calculation circuit, and based on the interval of the reflectors.