An Active Machine Vision System for Surface Quality Inspection

The realization of an integrated, flexible and robust CIM vision system, suitable for performing quality assurance surface inspections is discussed. The optimized combination of advanced optics, optomechanics and flexible image sensor realizes a high "virtual resolution" without penalizing the pixel transfer rate. High computation rates are obtained by complementing the fractal inspection algorithm with a dynamic hologram, a modular data flow processor and the system computer. The integrated system is centred around the camera head with a tiltable mirror, a digital zoom lens, a dynamic hologram, and a programmable image sensor. The hardware control of the submodules is done by a custom developed optocontroller and the FRAX bus. For changing the window of attention, a tiltable mirror is mounted in front of the optical zoom. The dedicated image sensor, realized in a 1.5 µm CMOS technology, as as main features a selectable frame rate and integration time, random access of region of intere st, and reatime programmability of the sensor resolution. The integrated vision system is validated for the surface quality inspection of concrete tiles in an industrial environment. The overall system performance is discussed in detail and the potential of the system for other application fields will be addressed.