Optoelectronic dimensional integral inspection of hollow cylinder-type articles for conveyor line

The results of development of noncontact optico-electronic real time system for integral dimensional inspection of atomic reactor parts, as hollow cylinders made of soft alloy, are given. This cheap, reliable and robust system for the industrial operation is based on shadow method for measuring the outside diameter and straightness deviation as well as on the triangulation method for measuring the inside diameter. For the shadow method the main sources of errors are caused by the influence of volumetric properties of 3D objects on the structure of shadow image, the inaccuracy of approximation of object's edge position caused by linear photodiode array as well as the aberration of optical system. By choosing type of the optical system and using look-up table algorithm for aberration correction as well as the cubic approximation of object's edge profile under its reconstruction allows to reduce the maximal total error up to 2 micrometer when the speed of measurement is 500 Hz. The optimization of triangulation system parameters under operation with technical (machined) surface objects in a real hard workshop conditions (high temperature range, dust) was made. The using hardware signal processor for median algorithm data processing is optimal as to the accuracy and frequency response of measurement. The developed system allows inspection articles with outside diameter up to 50 mm, inside diameter 43 mm, length -- up to 150 mm, straightness deviation equal to 0,3 mm with errors 0.014 mm for diameters, 0.040 mm for length and 0.020 mm for straightness deviation. At present the system is operating on the technological conveyer line for real time inspection of atomic reactor details (loading and unloading are made by manipulator) on the nuclear enterprise.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.