Shape inspection system with real-time adaptation to the luminance of the objects

摘要

This work presents an automated shape inspection system for two-dimensional objects with variable luminance. The system installed in the steel industry, captures linear images of plates at high temperature (700-1200 deg C) while they are moving on a roll path. The main objective of the system is to capture the shape of the head and tail of the plates. These shapes are used to optimize the rolling parameters of the plate mill in order to minimize waste. The radiation generated by the plates in the visible and infrared zones of the spectrum (largely dependent on their temperature) is directly captured by the linear camera of the system with no additional artificial illumination. While most of the research work has been focused on obtaining the optimal illumination for the objects inspected, this work deals with the particular case of objects which irradiate their own light. This system automatically adapts itself to acquire images of plates with different levels of luminance using a mechanism that calculates the proper exposure time to acquire each image. The mechanism integrates two basic actions: a feedforward control and an adaptive feedback control loop.