학술논문

Automatic Color Inspection for Colored Wires in Electric Cables
Document Type
Periodical
Source
IEEE Transactions on Automation Science and Engineering IEEE Trans. Automat. Sci. Eng. Automation Science and Engineering, IEEE Transactions on. 12(2):596-607 Apr, 2015
Subject
Robotics and Control Systems
Power, Energy and Industry Applications
Components, Circuits, Devices and Systems
Wires
Image color analysis
Inspection
Connectors
Visualization
Crimping
Cable crimping
wire color measurement
wire color sequence
wire detection
visual inspection
Language
ISSN
1545-5955
1558-3783
Abstract
In this paper, an automatic optical inspection system for checking the sequence of colored wires in electric cable is presented. The system is able to inspect cables with flat connectors differing in the type and number of wires. This variability is managed in an automatic way by means of a self-learning subsystem and does not require manual input from the operator or loading new data to the machine. The system is coupled to a connector crimping machine and once the model of a correct cable is learned, it can automatically inspect each cable assembled by the machine. The main contributions of this paper are: (i) the self-learning system; (ii) a robust segmentation algorithm for extracting wires from images even if they are strongly bent and partially overlapped; and (iii) a color recognition algorithm able to cope with highlights and different finishing of the wire insulation. We report the system evaluation over a period of several months during the actual production of large batches of different cables; tests demonstrated a high level of accuracy and the absence of false negatives, which is a key point in order to guarantee defect-free productions.