EuroWire March 2019

Technical Article

3 Machine vision

and specialised optical hardware. This diameter measurement technology is currently designed to precisely measure product with an accuracy of 1 micron. 3.2.2 Reduce frequency of defects The system can provide the operator with a view of current product images as well as both the most recent diameter defect and the current cable diameter. This continuous stream of real-time information – especially failure data – allows the operator to isolate the causes of diameter imperfections. Identifying when and how a defect occurs allows technical staff to learn the root cause of defects and reduce their occurrence. 3.2.3 Quality assurance The ZT system will continuously monitor the diameter of the product. The measurements and defect information can be recorded for later analysis. Images of diameter defects such as lumps and neck-downs are captured and saved to a hard disk for use in quality reports. The ZT system’s display makes it easy for engineering and production supervisors to examine potential defects without having to view the defect on the actual product itself – saving significant amounts of time. Defect images are saved together with location information, allowing operators to quickly find and eliminate defects before further processing is performed or product fails in the field. 3.3 Limitations There are a few limitations to the ZT system: • With today’s production lines maximising use of space, installing additional equipment on-line can be a concern. The ZT is able to modify its stand and camera box to best utilise the available spacing, and can even be installed with different orientations to provide additional flexibility • As the system’s camera is looking at the surface, water droplets/grease/ dust particles will affect the geometry of the product and will impact diameter measurements. Generally, this can be fixed with a well-placed air wipe. Alternatively, the system sensitivity can be decreased, which may result in some of the smaller defects passing through the filter 3.4 Test results The ZT system has been tested on numerous high-speed production areas in the world (eg draw towers). The images were taken of real defects in lines at production speeds ranging from several hundred to several thousand metres per minute.

inspection system

3.1 Optical mechanical design The ZT system utilises intense LED backlighting to create a sharply defined product edge. A high-speed camera orientated orthogonally to the product continually captures images of the entire width of the product at speeds up to 3,000m/min. Specialised optical lenses ensure that the product does not appear to change size while it remains within the camera’s field of view. Potential vibration of the product is handled through the use of image processing software to steady captured images. To ensure image consistency and to prevent ambient lighting from impacting operation, the ZT system includes an enclosure for the lighting and camera. Once the images are captured, an advanced algorithm is used to process the images, measure diameter, and scan for diameter defects such as lumps, neck-downs and diameter changes. If a defect is detected by the ZT system, an alarm will notify the operator and an error report is saved, along with an actual image of the defect. The defect will also appear on-screen for the operator to validate or reject. 3.2 Improving quality assurance 3.2.1 Suitable for any high-speed application As Taymer’s high-speed diameter measurement system uses machine vision, it is suitable for scanning for diameter defects on any type of round product, including bare wire, optical fibre, pipe, tube, jacketed wire and more. It is a thorough method of detecting diameter flaws due to its unique scanning algorithm ▼ ▼ Figure 1 : Detected diameter defects on fibre, left, compared with off-line microscope image, right

▲ ▲ Figure 2 : Image of diameter defect

Figure 1 shows a saved defect image from the ZT system compared to a microscope image of the same defect. Figure 2 shows a sample image of a diameter defect. 4 Conclusions With the high-speed ZT system, diameter is accurately measured and recorded, along with diameter defect information and defect images. benefits: • Suitability for any type of product • Ensuring the customer will not get defective products, improving customer relationship and confidence • Reducing rework and eliminating waste, thereby reducing material and labour costs • Assisting in internal improvements to production processes to reduce defects Courtesy of IWCS 2018 Cable & Connectivity Symposium, Providence, Rhode Island, USA, October 2018. This functionality provides several

Taymer International Inc Markham, Ontario, Canada Tel : +1 905 479 2614 Email : craig.girdwood@taymer.com Website : www.taymer.com

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March 2019