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Wire and Cable Technology International March/April 2015 : Page 178

Importance of Automated Machine Vision Systems in Jacket Wall Thickness Measurements Ananda Mysore, President, Angle Systems LLC www.anglesystems.com Stefan Strobel, Engineering Manager, TE Connectivity www.te.com The utilization of machine vision technology in the cable and tubing manufacturing industry is increasing rapidly. With the availability of high-speed cameras and computers, it makes machine vision technology very cost effective and reliable for use in high-volume manufacturing. In cable and tube manufacturing, good control of the extrusion of jackets is very important. This is because not maintaining the wall thickness of the extruded jacket within the tolerances either results in poor qual-ity, high cost or both. During the setup of an extrusion process, an operator has to adjust the thickness and concentricity either manually or by using an automated mechanism. In order to make these adjustments, an operator needs to cut and measure the part. The current measurement methods include a manual microscope with reticle, a tool maker’s microscope or even a method as coarse as using a caliper. Many of these measurement methods have a measurement resolution of 0.001" or coarser. Therefore these methods are highly subjective and time consuming. Depending on how many times the operator adjusts the parameters to get the right concentricity, the measurement time will be multiplied by that much iteration, and hence a high amount of scrap material is generated. And there is a quality issue depending on the operator’s judgement on these thick-ness measurements. Many machine vision systems have been proposed to solve this. One such system is the WTVS (Wall Thick-ness Vision System) series from Angle 178 Wire Harness & Cable Connector Systems LLC , Mountain View, CA, USA. This is a fully automated measurement system that can be used for off-line measurements in a production environment. The system can measure single, double or triple-wall measurements automatically in less than 10 seconds with minimal operator intervention. This system has a measurement resolution of 0.0001", and saves the manufacturer a significant amount of time, making a rather tedious task of measuring very small parts com-pleted in the blink of an eye with high accuracy, when compared with manual measurements (see Figure 1 ). Fig. 1 — Wall Thickness Vision System (WTVS). Case Study Here is a case study done by TE connectivity in Menlo Park, CA, USA, showing the cost saving using WTVS in a production environment. Figure 2 shows extru-Fig. 2 — Extrusion set-up scrap with a manual microscope. March 2015

Importance Of Automated Machine Vision Systems In Jacket Wall Thickness Measurements

Ananda Mysore

Ananda Mysore, President, Angle Systems LLC www.anglesystems.com Stefan Strobel, Engineering Manager, TE Connectivity www.te.com

The utilization of machine vision technology in the cable and tubing manufacturing industry is increasing rapidly. With the availability of high-speed cameras and computers, it makes machine vision technology very cost effective and reliable for use in high-volume manufacturing.

In cable and tube manufacturing, good control of the extrusion of jackets is very important. This is because not maintaining the wall thickness of the extruded jacket within the tolerances either results in poor quality, high cost or both.

During the setup of an extrusion process, an operator has to adjust the thickness and concentricity either manually or by using an automated mechanism. In order to make these adjustments, an operator needs to cut and measure the part. The current measurement methods include a manual microscope with reticle, a tool maker’s microscope or even a method as coarse as using a caliper. Many of these measurement methods have a measurement resolution of 0.001" or coarser. Therefore these methods are highly subjective and time consuming. Depending on how many times the operator adjusts the parameters to get the right concentricity, the measurement time will be multiplied by that much iteration, and hence a high amount of scrap material is generated.

And there is a quality issue depending on the operator’s judgement on these thickness measurements. Many machine vision systems have been proposed to solve this.

One such system is the WTVS (Wall Thickness Vision System) series from Angle Systems LLC, Mountain View, CA, USA. This is a fully automated measurement system that can be used for off-line measurements in a production environment. The system can measure single, double or triple-wall measurements automatically in less than 10 seconds with minimal operator intervention. This system has a measurement resolution of 0.0001", and saves the manufacturer a significant amount of time, making a rather tedious task of measuring very small parts completed in the blink of an eye with high accuracy, when compared with manual measurements (see Figure 1).

Case Study

Here is a case study done by TE connectivity in Menlo Park, CA, USA, showing the cost saving using WTVS in a production environment. Figure 2 shows extrusion set-up scrap when measurements are performed with a manual microscope. Figure 3 shows extrusion set-up scrap when measurements are performed with the WTVS system.

This results of this case study shown in Figure 2 and Figure 3 indicate the savings of 42% in the set-up scrap when the system is running at 500 FPM.

Measurement System

Angle Systems’ Wall Thickness Vision System is a bench-top, vision-based measurement system that utilizes a high-resolution industrial camera with a high-precision imaging system. The system includes a touch screen monitor that is very user friendly and requires minimum operator interaction. The system is factory calibrated using a NIST-traceable standard. The features of the Angle Systems WTVS system are shown in Figure 4.

What makes the WTVS software unique and valuable is that it not only takes measurements automatically within a matter of seconds, but also records the data into a printable inspection report thus eliminating the manual methods of recording.

This automated feature significantly reduces the operator-to-operator variation. The data can also be saved as a TXT or CSV file for further statistical analysis or stored for future records.

This system also has a multitude of measurement capabilities. Inner and outer diameter, single and dual wall, interstices, multi-tubing, wall thickness, concentricity, minimum and maximum, average and the range are all featured measurements in the Wall Thickness Vision System.

The use of an automated machine vision system not only reduces the set-up scrap material, but also improves the quality of the product by eliminating operator subjectivity in making accurate measurements. The rate of return on a WTVS System could be as quick as two to three months depending on the type of material. Www.anglesystems.com / www.te.com

The authors would like to acknowledge the contribution of Robert Gerber of TE Connectivity and Michael Signorelli, Gregory Calimpong and Taylor Stoddard of Angle Systems LLC.

More About Angle Systems LLC...

Angle Systems LLC, which was founded in 2009, is a designer, developer and manufacturer of high-speed metrology, inspection and automation system solutions involving vision and laser-based sensor technologies. www.anglesystems.com

Read the full article at http://www.bluetoad.com/article/Importance+Of+Automated+Machine+Vision+Systems+In+Jacket+Wall+Thickness+Measurements/1963122/251043/article.html.

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