DISTANCE MEASUREMENT DEVICE AND DISTANCE MEASUREMENT METHOD

PROBLEM TO BE SOLVED: To provide a distance measurement device and distance measurement method that can make distance measurements even when a position of a measurement object displaces.SOLUTION: Firstly, a distance measurement device comprises: an amplitude determination unit that determines amplitude of an AC component of an optical frequency of an optical wave on the basis of an optical distance difference calculated by a distance difference calculation unit, and determines amplitude in which a modulation index determining an aspect ratio of a Lissajous waveform is kept constant; and an amplitude control unit that controls amplitude of an optical wave to be created by an optical wave creation unit on the basis of a determination result of the amplitude determination unit. Secondary, the distance measurement device comprises: a time lag detection unit that detects a time lag between measurement light and reference light on the basis of the optical distance difference calculated by the distance difference calculation unit; and a detection control unit that corrects phases of a first reference sinusoidal signal and a second reference sinusoidal signal on the basis of a detection result of the time lag detection unit, and causes a sinusoidal signal detection unit to execute detection of a dual-phase sinusoidal signal on the basis of phase-corrected first reference sinusoidal signal and second reference sinusoidal signal.SELECTED DRAWING: Figure 12 【課題】測定対象物の位置が変位する場合でも距離測定を行うことができる距離測定装置及び距離測定方法を提供する。【解決手段】第１に、距離差算出部が算出した光学的距離差に基づき光波の光周波数の交流成分の振幅を決定する振幅決定部であって、且つリサージュ波形のアスペクト比を決定する変調指数が一定に保たれる振幅を決定する振幅決定部と、振幅決定部の決定結果に基づき光波生成部が生成する光波の振幅を制御する振幅制御部とを備える。第２に、距離差算出部が算出した光学的距離差に基づき、測定光と参照光との間の時間遅れを検出する時間遅れ検出部と、時間遅れ検出部の検出結果に基づき第１参照正弦波信号及び第２参照正弦波信号の位相を補正し、位相補正後の第１参照正弦波信号及び第２参照正弦波信号に基づき正弦波信号検出部に２相の正弦波信号の検出を実行させる検出制御部とを備える。【選択図】図１２