Though error-proofing sensors and poka yoke have been around for decades, continuing advancements related to the Industrial Internet of Things (IIoT) are making both more accessible and easier to maintain.
Designed to eliminate product defects by preventing human errors or correcting them in real time, poka yoke has been a key to a lean manufacturing process since it was first applied to industrial applications in 1960. Today, error proofing relies far less on manual mechanisms and more on IoT-enabled error proofing sensors that connect devices and systems across the shop floor.
IoT is enabling immediate control of error-proofing devices such as sensors. This immediacy guards against error-proofing devices being bypassed, which has been a real problem for many years. Now, if a sensor needs adjustment it can be done remotely. A good example of this is with color sensors. When receiving sub-components from suppliers, colors can shift slightly. If the quality group identifies the color lot as acceptable but the sensor does not, often the color sensor is bypassed to keep production moving until someone can address it, creating a vulnerable situation. By using IoT-enabled sensors, the color sensor can be adjusted remotely at any time or from any location.
The detection of errors has been greatly improved by integrating sensors directly into the processes. This is a major trend in flexible manufacturing where poka yoke devices have to be adjusted on-the-fly based on the specific product version being manufactured. This means that buttons or potentiometers on discrete sensors are not adequate. Sensors must provide true data to the control system or offer a means to program them remotely. They must also connect into the traceability system, so they know the exact product version is being made. Connections like this are rapidly migrating to IO-Link. This technology is driving flexible manufacturing at an accelerated rate.
IO-Link enables sensors to process and produce enriched data sets. This data can then be used to optimize efficiencies in an automated process, increase productivity and minimize errors.
Additionally, the easily expandable architecture built around IO-Link allows for easy integrations of poka yoke and industrial identification devices. By keeping a few IO-Link ports open, future expansion is easy and cost effective. For poka yoke, it is important that the system can be easily expanded and that updates are cost-effective.
However this can sometimes be the easy part of the project. Many times a great sensor solution is identified but the proper controls inputs are not available or the control architecture doesn’t support analog inputs or network connections. The amount of time and dollar investments to integrate the sensor solution dramatically increases and sometimes the best poka-yoke solutions go un-implemented!”
“Sometimes the best poka-yoke solutions go un-implemented!”
Many of our customers are finding that the best controls architecture for their continuous improvement processes involves the use of IO-Link integrated with their existing architectures. It can be very quickly integrated into the existing controls and has a wide variety of technologies available. Both of these factors make it the best for integrating Poka-yoke or Mistake Proofing due to the great flexibility and easy integration.
Download this whitepaper and read about how a continuous improvement technician installed and integrated an error-proofing sensor in 20 minutes!
Vision sensors are powerful Poka-Yoke tools ideal for error proofing your process. However, traditional sensors still solve more applications at a much lower cost. So, how do you decide when to jump up to a vision sensor? There are three application categories that require the use of a vision sensor, which include:
Parts are not well fixtured: If the part is not contained in a fixture, or there is no opportunity to bring the part into an inspection station that has better tolerance, then a vision system is the best choice. Example: parts directly on moving conveyor belt.
Balluff has the opportunity to share some of the company’s proven Error-Proofing Techniques in a Seminar at Fabtech on November 14, 2011 in McCormick Place in Chicago, Illinois. The session is segmented into two areas:
Automated/Robotic Weld Cell Process Improvement. We continue to see a great deal of need in this arena. When the economy tanked in 2007/2008, many companies inside and outside of the Automotive Industry were on the edge and many good, talented people were let go. In some cases, the people whose jobs were eliminated had many years of experience in maintenance and in manufacturing engineering. When volumes of work came back, so did the problems associated with weld cell nesting, Poka-Yoke, clamp sensing because of loading impact, weld debris hostility and other issues related to peripheral sensing devices in weld cells; in many cases, without the experienced personnel to reduce time in consumption used to address a wide range of problems. In this session, we will discuss and provide examples of proven techniques aimed squarely at these productivity and time-wasting problems that will return significant ROI for many customers.