3D Vision Systems
3D machine vision systems typically comprise multiple cameras or one or more laser displacement sensors.
Multi-camera 3D vision in robotic guidance applications provides the robot with part orientation information. These systems involve multiple cameras mounted at different locations and "triangulation" on an objective position in 3-D space.
In contrast, 3D laser-displacement sensor applications typically include surface inspection and volume measurement, producing 3D results with as few as a single camera. A height map is generated from the displacement of the reflected lasers' location on an object. The object or camera must be moved to scan the entire product similar to line scanning. With a calibrated offset laser, displacement sensors can measure parameters such as surface height and planarity with accuracy within 20 μm. Figure 15 shows a 3D laser displacement sensor inspecting brake pad surfaces for defects.