High-speed 3D surface measurement with a fringe projection based optical sensor

A new optical sensor based on fringe projection technique for the accurate and fast measurement of the surface of objects mainly for industrial inspection tasks is introduced. High-speed fringe projection and image recording with 180 Hz allows 3D rates up to 60 Hz. The high measurement velocity was achieved by consequent fringe code reduction and parallel data processing. Reduction of the image sequence length was obtained by omission of the Gray-code sequence by using the geometric restrictions of the measurement objects. The sensor realizes three different measurement fields between 20 x 20 mm2 and 40 x 40 mm2 with lateral spatial solutions between 10 ?m and 20 µm with the same working distance. Measurement object height extension is between ± 0.5 mm and ± 2 mm. Height resolution between 1 µm and 5 µm can be achieved depending on the properties of the measurement objects. The sensor may be used e.g. for quality inspection of conductor boards or plugs in real-time industrial applications.