PURPOSE: To detect the working position with high precision by irradiating a working part with a slit light, performing a differential operation to an obtained optical cut image, calculating a value of an average luminance of the optical cut image corresponding to the obtained differential image, adjusting the slit light in accordance with the calculated value and processing the optical cut image again.
CONSTITUTION: An optical cut image 9 of a working part obtained at the time of radiating a slit light 7 by some light quantity is inputted, and by performing a differential operation to this optical cut image 9, a differential image is generated. Subsequently, a value of an average luminance of optical cut image data corresponding to this differential image area is calculated. Next, based on this value, whether a state of the optical cut image is suitable for detecting a working position or not is decided, and when it is unsuitable, the light quantity of the slit light 7 is adjusted in accordance with a difference between a state of the optical cut image and a scheduled optimum state. Thereafter, after the adjustment, by processing the inputted optical cut image again, the working position is detected.
HIRAI AKIRA
SATOU SACHIE
KAWASAKI KYOICHI
KASHIMA ATSUHIKO
HITACHI CONSTRUCTION MACHINERY