Realize Productivity Gains with Smart Robotic Tooling

In my last blog post, I shared how implementing IO-Link can expand visibility into your robot implementations and secure a high ROI. In this blog, I will share how you can better capitalize on your robot utilization and gain productivity with pneumatic and electric smart grippers.

Using Pneumatic & Electric Smart Grippers

Figure 1 – Sensors used in grippers provide position and open/closed feedback of the jaw. Photo courtesy of Balluff Worldwide.

In traditional pneumatic gripper applications, sensors are often not utilized. Proper function is assumed, i.e., the jaw opened and closed properly based on the signal sent to the air valve. This can cause unnecessary collisions or process failures due to stuck/worn mechanical components, leaks in the pneumatic lines, or small variations in the process cycle. Adding sensors to the grippers (Figure 1), creates a closed loop and minimal discrete feedback, like open or closed jaw, is provided. With the addition of smart sensors, we can monitor exact gripper jaw position and provide application diagnostics improving the capabilities of the robot end-effector. And finally, gripper intelligence features are expanded even further with electric grippers, giving precise control over the motion profile of the tool and providing detailed condition data on the equipment.

Regularly for smart sensors and smart grippers, these commands and the data are handled via IO-Link communication, which allows for process data, parameter data, and event data to be shared with the PLC and monitored via the Industrial Internet of Things (IIoT) connections. By utilizing IO-Link, both electric and pneumatic grippers can be enabled with intelligence to improve robot implementations.

Part Quality, Inspection, Delicate Part Handling & Measurement

Some of the most common applications like bin-picking, part stacking, or blank de-stacking make assumptions about the part being handled. But the first assumption many people make is that the robot is holding a part. Without sensor verification that the part is in place, how can it be guaranteed that the process is running without defect? And a second assumption that the correct part was loaded into the machine by the operator can cause hundreds of part defects if continued without verification. It is vital that the right part is loaded into the equipment every time, and as many parts look very similar manual inspection isn’t always accurate.  A gripper is an excellent place to gauge and inspect parts as it is physically touching the part. This is done by utilizing an analog position measurement sensor to determine the distance change of the gripper jaw. In addition to this, the position measurement sensor also can provide feedback for tactile gripping applications when handling delicate or precise parts. By utilizing position sensing for inspection and handling of the part, we can improve part quality and reduce production defects.

Production Flexibility, Format Change & Part Identification

In addition to quality inspection, by measuring the part, we can identify the part and make automation changes on-the-fly based upon this information, creating much higher levels of flexibility and making it possible for in-process format change. With one piece of equipment and the utilization of smart sensors on pneumatic grippers or smart electric grippers, more product can be produced. With higher efficiencies manufacturers can realize significant productivity gains.

Figure 2 – GEH6060IL-03-B servo electric gripper with delicate or elastic parts. Photo courtesy of Zimmer Group US, Inc.

In my next blog, I will discuss how expanding the use of end-effectors adds flexibility and are now easier than ever to include in your robotic applications.

Tackle Quality Issues and Improve OEE in Vision Systems for Packaging

Packaging industries must operate with the highest standards of quality and productivity. Overall Equipment Effectiveness (OEE) is a scoring system widely used to track production processes in packaging. An OEE score is calculated using data specifying quality (percent of good parts), performance (performance of nominal speed) and equipment availability (percent of planned uptime).

Quality issues can directly impact the customer, so it is essential to have processes in place to ensure the product is safe to use and appropriately labeled before it ships out. Additionally, defects to the packaging like dents, scratches and inadequate labeling can affect customer confidence in a product and their willingness to buy it at the store. Issues with quality can lead to unplanned downtime, waste and loss of productivity, affecting all three metrics of the OEE score.

1.png

Traditionally, visual inspections and packaging line audits have been used to monitor quality, however, this labor can be challenging in high volume applications. Sensing solutions can be used to partly automate the process, but complex demands, including multiple package formats and product formulas in the same line, require the flexibility that machine vision offers. Machine vision is also a vital component in adding traceability down to the unit in case a quality defect or product recall does occur.

2.JPG

Vision systems can increase productivity in a packaging line by reducing the amount of planned and unplanned downtime for manual quality inspection. Vision can be reliably used to detect quality defects as soon as they happen. With this information, a company can make educated improvements to the equipment to improve repeatability and OEE and ensure that no defective product reaches the customers’ hands.

Some vision applications for quality assurance in packaging include:

  • Label inspection (presence, integrity, print quality, OCV/OCR)
    • Check that a label is in place, lined up correctly and free of scratches and tears. Ensure that any printed graphics, codes and text are legible and printed with the expected quality. Use a combination of OCR (Optical Character Recognition) to read a lot number, expiration date or product information, and then OCV (Optical Character Verification) to ensure legibility.
  • Primary and secondary packaging inspection for dents and damage
    Inspect bottles, cans and boxes to make sure that their geometry has not been altered during the manufacturing process. For example, check that a bottle rim is circular and has not been crushed so that the bottle cap can be put on after filling with product.
  • Safety seal/cap presence and position verification
    Verifying that a cap and/or seal has been placed correctly on a bottle, and/or that the container being used is the correct one for the formula / product being manufactured.
  • Product position verification in packages with multiple items
    In packages of solids, making sure they have been filled adequately and in the correct sequence. In pharmaceutical industries, this can be used to check that blister packs have a pill in each space, and in food industries to ensure that the correct food item is placed in each space of the package.
  • Certification of proper liquid level in containers
    For applications in which it can’t be done reliably with traditional sensing technologies, vision systems can be used to ensure that a bottle has been filled to its nominal volume.

The flexibility of vision systems allows for addressing these complex applications and many more with a well-designed vision solution.

For more information on Balluff vision solutions and applications, visit www.balluff.com.

Eliminating Manufacturing Errors Begins with Identifying Trouble Spots

We have all gotten that dreaded phone call or email…the customer received their order, but there was a significant problem:

  • ErrorProofingTagsMissing part
  • Wrong color
  • Leaking seal
  • Improper assembly
  • Too lose…or too tight
  • Incomplete processing, e.g. missing threads
  • Something is damaged
  • Missing fluids or fluids at wrong level
  • …and so on

Assuming that we have reliable suppliers delivering quality parts that meet the required specifications…everything else that can (and often does) go wrong happens inside our own facilities. That means that solving the issues is our responsibility, but it also means that the solutions are completely under our control.

During the initial quality response meetings, at some point the subjects of “better worker training” and “more attention to detail and self-inspection” may come up. They are valid subjects that need to be addressed, but let’s face it: not every manufacturing and assembly problem can be solved by increased worker vigilance and dedication to workmanship. Nor, for that matter, is there the luxury of time or capacity for each worker to spend the extra time needed to ensure zero defects through inspection.

It is often more effective to eliminate errors at their source before they occur, so that further human intervention isn’t required or expected.

Some things to look for when searching for manufacturing trouble spots:

  • Are all fasteners present and properly tightened, in the proper torque sequence
  • Correct machine setup: is the right tool or fixture in place for the product being produced?
  • Manual data entry: does the process rely on human accuracy to input machine or product data?
  • Incorrect part: is it simply too hard to determine small differences by visual means alone?
  • Sequencing error: were the parts correct but came together in the wrong sequence?
  • Mislabeled component: would the operator realize that part is wrong if it was labeled incorrectly in the first place? Sometimes where the error has impact and where it actually occurred are in two different places.
  • Part not seated correctly: is everything is correct, but sometimes the part doesn’t sit properly in the assembly fixture?
  • Critical fluids: is the right fluid installed? Is it filled to the proper level?

Once the trouble spots have been identified, the next step is to implement a detection and/or prevention strategy. More information on the error proofing process is available on the Balluff website at www.balluff.us/errorproofing