MOTION CONTROL SYSTEM OF NUMERICAL CONTROL MACHINE TOOL UNDER IMAGE PROCESSING

• Published in: International Journal of Mechatronics & Applied Mechanics 2020-11, Vol.i (8), p.21-30
• Main Authors: Zeng, Qi, Luu, Viet Hung, Saedudin, Rd Rohmat
• Format: Article
• Language: English
• Subjects: Accuracy; Actuators; Algorithms; Automation; Cameras; Control systems; Controllers; Digital imaging; Edge detection; Efficiency; Hough transformation; Image processing; Machine tools; Mathematical analysis; Motion control; Movement; Numerical controls; Optimization; Sensors; Software; Straight lines; Tool setting; Vision systems; Workpieces
• ISSN: 2559-4397; 2559-6497
• DOI: 10.17683/ijomam/issue8.35

This paper is to study the overall structure of the motion control system of the numerical control machine tool to improve motion control precision. It performs digital image processing on the obtained workpiece image, extracts the coordinate of the tool setting point, and calculates the distance of the tool setting. Comparison of algorithms in image processing accomplished and improved to increase the positioning accuracy and stability of the tool setting system. The results show that to improve the effect of workpiece edge detection, recommended by this study based on the Canny operator, and the morphological processing of the fusion image to detect the edge of the workpiece. In the algorithm of tool setting point coordinate extraction, an improved Hough transform algorithm is used to extract the coordinates of the center of a rectangular workpiece and a circular workpiece respectively, which reduces the complexity of the algorithm. In the algorithm of calculating the distance from the tool tip to the tool setting point, the optimization principle of the distance from the point to the straight line is used to determine the tool tip. Then, the descending distance of the tool is determined in the tool setting, completing the extraction of the three-dimensional machine coordinate of the tool setting point. Based on the camera calibration, the image is processed using a visual positioning software algorithm to extract the machine coordinates of the tool setting point of the workpiece and the tool's descending distance. The motion information instruction is sent to the motion controller via the host computer. The motion controller controls the movement of the actuator, adjusts the movement distance of the three axes of the machine tool, to complete an automatic tool setting of the workpiece of the numerical control machine tool. It improves the intelligence and automation of the numerical control machine tool setting technology.