Development of a 3D vision range sensor equiphase light-section method

Many of autonomous robots or industrial robots require three-dimensional environmental sensors. Stereo visions or laser range finders are often used to detect distance to obstacles or targets. A new type of three-dimensional measurement system is proposed in this paper. This method is a kind of active stereo vision based on light-section method and phase-shift method. A special light source that consists of a rotating cylinder and a lamp is used. It projects planes of lights whose intensities vary in a sinusoidal function of time. Phase of each plane is different from those of other plane, and we can distinguish which plane sectioned the target from the phase. The images obtained from video camera are processed into phase of each pixel that indicates distance to measuring targets. The method needs only simple calculation for the detection of phase. The basic principle and expanded methods for practical use are proposed in this paper. The experimental results using trial system are also given, which show effectiveness of the method.