Back to the Basics – Object Detection

In the last post about the Basics of Automation, we discussed how humans act as a paradigm for automation. Now, let’s take a closer look at how objects can be detected, collected and positioned with the help of sensors.

Sensors can detect various materials such as metals, non-metals, solids and liquids, all completely without contact. You can use magnetic fields, light and sound to do this. The type of material you are trying to detect will determine the type of sensor technology that you will use.

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Types of Sensors

  • Inductive sensors for detecting any metallic object at close range
  • Capacitive sensors for detecting the presence of level of almost any material and liquid at close range
  • Photoelectric sensors such as diffuse, retro-reflective or through-beam detect virtually any object over greater distances
  • Ultrasonic sensors for detecting virtually any object over greater distances

Different Sensors for Different Applications

The different types of sensors used will depend on the type of application. For example, you will use different sensors for metal detection, non-metal detection, magnet detection, and level detection.

Detecting Metals

If a workpiece or similar metallic objects Object Detection 2should be detected, then an inductive sensor is the best solution. Inductive sensors easily detect workpiece carriers at close range. If a workpiece is missing it will be reliably detected. Photoelectric sensors detect small objects, for example, steel springs as they are brought in for processing. Thus ensures a correct installation and assists in process continuity. These sensors also stand out with their long ranges.

Detecting Non-Metals

If you are trying to detect non-metal objects, for example, the height of paper stacks, Object Detection 3then capacitive sensors are the right choice. They will ensure that the printing process runs smoothly and they prevent transport backups. If you are checking the presence of photovoltaic cells or similar objects as they are brought in for processing, then photoelectic sensors would be the correct choice for the application.

Detecting Magnets

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To make sure that blister packs are exactly positioned in boxes or that improperly packaged matches are sorted out, a magnetic field sensor is needed which is integrated into the slot. It detects the opening condition of a gripper, or the position of a pneumatic ejector.

 

Level Detection

What if you need to detect the level of granulate in containers? Then the solution is to use capacitive sensors. To accomplish this, two sensors are attached in the containers, offset from each other. A signal is generated when the minimum or maximum level is exceeded. This prevents over-filling or the level falling below a set amount. However, if you would like to detect the precise fill height of a tank without contact, then the solution would be to use an ultrasonic sensor.

Stay tuned for future posts that will cover the essentials of automation. To learn more about the Basics of Automation in the meantime, visit www.balluff.com.

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Safety Over IO-Link Helps Enable Human-Robot Collaboration

Safety Over IO-Link makes it easier to align a robot’s restricted and safeguarded spaces, simplifies creation of more dynamic safety zones and allows creation of “layers” of sensors around a robot work area.

For the past several years, “collaboration” has been a hot topic in robotics.  The idea is that humans and robots can work closely together, in a safe and productive manner.  Changes in technology and standards have created the environment for this close cooperation. These standards call out four collaborative modes of operation: Power & Force Limiting, Hand Guiding, Safety Rated Monitored Stop, and Speed & Separation Monitoring (these are defined in ISO/TS 15066).

Power & Force Limiting

Power & Force Limiting is what many people refer to when speaking about Collaborative Robots, and it applies to robots such as Baxter from Rethink Robotics and the UR series made by Universal Robots.  While the growth in this segment has been fast, there are projections that traditional robots will continue to make up 2/3 of the market through 2025, which means that many users will want to improve their traditional robot solutions to “collaborate”.

Hand Guiding

Hand guiding is the least commonly applied mode, it is used for very specific applications such as power assist (one example is loading spare tires into a new car). It generally requires special equipment mounted on the robot to facilitate the guiding function.

Safety Rated Monitored Stop and Speed & Separation Monitoring

Safety Rated Monitored Stop and Speed & Separation Monitoring are especially interesting for traditional robots, and require safety sensors and controls to be implemented.  Customers wanting closer human-robot collaboration using traditional robots will need devices such as safety laser scanners, safety position sensors, safety PLCs and even safety networks – this is where Safety Over IO-Link can enable collaborative applications.

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Many of IO-Link’s well-known features also provide advantages for traditional robot builders and users:

1) Faster & cheaper integration/startup through reduction in cabling, standardized connectors/cables/sensors and device parameterization.

2) Better connection between sensors and controllers supports robot supplier implementation of IIoT and improved collaboration by making it easier to gather process, device and event data – this allows improved productivity/uptime, better troubleshooting, safer machines, preventative maintenance, etc.

3) Easier alignment of the robot’s restricted and safeguarded spaces, simplifying creation of more dynamic safety zones to support closer human-robot collaboration.

The third item is especially relevant in enabling collaborative operation of traditional robots.  The updated standards allow the creation of a “shared workspace” for the robot and human, and how they interact in this space depends on the collaborative mode.  At a simple level, Safety Rated Monitored Stop and Speed & Separation Monitoring require this “shared workspace” to be monitored, this is generally accomplished using a “restricted space” and a “safeguarded space.”  These “spaces” must be monitored using many sensors, both inside and outside the robot.

First, the robot’s “restricted space” is set up to limit the robot’s motion to a specific 3-dimensional volume.  In the past, this was set up through hard stops, limit switches or sensors, more recently the ANSI RIA R15.06 robot standard was updated to allow this to be done in software through safety-rated soft axis and space limiting.  Most robot suppliers offer a software tool such as “Safe Move” or Dual Check Safety” to allow the robot to monitor its own position and confirm it is where it is supposed to be.  This feature requires safe position feedback and many sensors built into the robot.  This space can change dynamically with the robot’s program, allowing more flexibility to safely move the robot and assure its location.

Second, a safeguarded space must be defined and monitored.  This is monitored using safety rated sensors to track the position of people and equipment around the robot and send stop (and in some cases warning) signals to the safety controller and robot.  Safety Over IO-Link helps connect and manage the safety devices, and quickly send their signals to the control system.

In the past, integrating a robot with safety meant wiring many safety sensors with long cable runs and many terminations back to a central cabinet.  This was a time consuming, labor intensive process with risk of miswiring or broken cables.  IO-Link significantly reduces the cost, speed and length of connections due to use of standard cables and connectors, and the network approach.  It is also much simpler for customers to change their layout using the network, master & hub approach.

Customers wanting collaborative capability in traditional robots will find that Safety Over IO-Link can significantly simplify and reduce the cost of the process of integrating the many advanced safety sensors into the application.

To learn more, visit www.balluff.com.

 

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DMC vs. RFID in Manufacturing

The increasing discussions and regulations on complete traceability and reliable identification of products is making identification systems an inevitable part in manufacturing. There are two specific technologies that are very well received: The Data Matrix Code (DMC) and Radio Frequency Identification (RFID).

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One critique of RFID is the market maturity regarding practicability and price-performance ratio is not reached yet. Compare this to DMC; DMC is practical and cost-effective which is an advantage over RFID. In order to choose DMC or RFID for your application, you have to understand the fundamental differences between the two technologies. Both have their advantages and disadvantages, and the wrong decision could have costly consequences. The technology you choose will mainly depend on the object being identified. The decision will be based off of size, shape and the environmental conditions.

A New World of Opportunities with DMC

A Data Matrix Code is a two-dimensional data point pattern that has a variable, rectangular size in the form of a matrix. The matrix consists of symbol elements with a minimum of 10×10 and a maximum of 144×144 . It is a binary code that is interpreted with zeros and ones and can hold up to 1,556 bytes.

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A horizontal and a vertical border describe a corner, which serves as orientation for the reading – called the “Finding Pattern”. On the remaining sides, the border must alternate with light and dark square elements in order to describe the position and size of the matrix structure – the “Alternating Pattern”. The data storage area is inside the symbol.

Advantages of DMC

This machine-readable coding form was invented to encode higher amounts of data in smaller areas compared to 1D code. Camera scanners can already reliably read dot patterns of only 2mm by 2mm. Thus DMC is suitable for very small products or round surfaces where there is little room for marking on the product.

With the technology of DMC you can place a lot of information in a very small area. Article or batch numbers, manufacturing or expiration dates as well as other important manufacturing data can be stored permanently on the work piece across all processing steps.

A particular strength also lies in the fact that the code can be directly applied to a part (without a label) using different printing or embossing methods. It can be needled, lasered or printed with inkjet or thermal transfer printing. It works with various materials: plastics, papers, metals and many more. Since you have to use special cameras to read the DMC, not barcode scanners, they can be read in any orientation (from 0°-360°).

Additionally, the error correction when reading a DMC is very high due to information redundancy and error correction algorithm, even 25-30% contamination or damage of the data field can be fully compensated.

Disadvantages of DMC

As it is not possible to read a DMC with linear barcode scanners, you have to use camera-based image processing systems that are more expensive. In addition, it is imperative that the entire surface (not just a part of it) is decoded, because the arrangement of the modules on the surface determines the contained data. Otherwise you don’t get any valuable information.

Although DMC can accommodate low-contrast printing (20% contrast are sufficient), glossy surfaces are difficult to handle because either the light used by the camera for reading is not optimally reflected or it is too scattered. The angle at which the camera is mounted can also play a role.

Last but not least, the location of the DMC or its attachment determines whether it is readable or not. Unlike RFID, a DMC can only be read with visual contact. A hidden DMC cannot be read by the cameras. Even if there is a line of sight you can read the DMC only within a specific reading distance.

Gain Visibility into the Manufacturing Process with RFID

This technology makes it possible to identify every item that is equipped with an RFID data carrier contactless and unambiguously. An RFID system in manufacturing consists of thousands of data carriers (also called tags or transponders) and a minimum of one read/write device (usually called a reader) with an antenna.

The reader generates a weak electromagnetic field via its antenna. If you bring a tag into this magnetic field, the microchip of the tag is supplied with energy and can send data (without contact) to the reader or store new information on the chip. If the tag leaves the magnetic field, the connection to the reader breaks off and the chip is inactive again. The stored data will remain in the tag memory.

RFID tags are available in many different designs, it can be just a simple adhesive tag but also a hard tag as a disc, bolt or glass tag. Only a few millimeter tags can be used for tool identification and very large transponders for container identification.

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Advantages of RFID

An RFID tag has 3 main advantages:

  • The tag can be read or written contactlessly without visual contact to the reader
  • The tag has almost unlimited rewritability
  • Several tags can be read simultaneously (multitag/bulk reading)

These features open up completely new possibilities that DMC cannot provide. If the RFID tag is integrated in a pallet or tool and you can’t even see it, it can still be identified. RFID tags can also be read with the greatest possible contamination as no visual contact is needed. With the rewritability of the tags you have the chance to change, delete or supplement the data on the chip – at any time.

Once an RFID system is integrated into a process, the system can be run with just minimal human participation. For a new order, the new information is written automatically on the tag. This can be up to 128 kbyte of data on a single tag. The detection of RFID-equipped parts happens within less than a second, much faster than using a barcode. This leads to reduced administrative errors, increased transparency and significant increase of speed.

With RFID, even after a post-treatment, parts can be tracked down for a lifetime. Every production step can be documented, read and written directly on the RFID tag in or on the part. To avoid security issues, data can be encrypted, password protected or set to include a “kill” feature to remove data permanently.

Disadvantages of RFID

RFID also has some disadvantages. Depending on the used frequency, physical conditions are often the reason for issues. For example, metal containers or contents made of metal can create problems or even non-readings as metals reflect and shield. Products with a high proportion of water absorb radio waves and it could cause the reader to not detect certain objects.

Another sore point is the cost. RFID tags are always more expensive than a DMC because even with a large amount, the integrated antenna and the transponder must be paid. However, with having almost unlimited read and write capabilities, the higher initial acquisition costs pay off over the time with tens of thousands of uses of the tags – at least with closed-loop applications.

Different frequencies for different applications

There are 3 established radio frequency ranges that have specific characteristics:

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The application determines which frequency you should choose. As Low Frequency (LF) systems only have a moderate sensitivity for potential metallic reflections they are designed for applications where the tag has to be mounted flush in metal, for example, with tool identification. High Frequency (HF) systems score with a high transmission speed for large volumes of data and are therefore ideal for work in progress (WIP) applications. High reading ranges make Ultra High Frequency (UHF) very attractive when the plant or process does not allow a close proximity between reader and tag, RFID tags on various positions on an item can be read with just a single UHF antenna. As all tags can be read out almost simultaneously in the read range of a reader, UHF systems are ideal for detecting complete pallet loads.

Main Differences Between DMC and RFID Tags

Here is an overview of the most important differences between Data Matrix Code and RFID:

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Which Option is Better for Your Application?

Ultimately, the decision to opt for one or the other technology is always a case-by-case decision. Here are some fundamental questions you can ask yourself in order to choose the right one:

  • Will the marked object be reused or will it be lost at the end of the processing chain? → closed-loop application = RFID, open loop application = DMC
  • Is there only a one-time marking or a repeated writing/ change of the stored data needed within the processing chain? → One-time marking = DMC,  rewriting = RFID
  • How big are the detection distances? → Short = DMC, large = RFID
  • What about the data volume on the object? → Low = DMC, high = RFID
  • Should process data be stored on the object? → Yes = RFID, no = DMC
  • What about the processing speed? Not relevant = DMC, high = RFID
  • What about the lighting conditions and contrasts? → Good = DMC, bad = RFID
  • How big is the space available for the marking? → Small = DMC, sufficient = RFID
  • Is the direct line of sight to the object difficult? → Yes = RFID, no = DMC
  • Are there potential sources of interference like dirt or damage? → Yes = RFID, no = DMC
  • Are there potential sources of interference like metals or liquids? → Yes = DMC, no = RFID

It’s Not Always About “Either/Or”

DMC and RFID do not necessarily have to compete. Sometimes it may be beneficial to have a combination of both technologies. An example of a combination solution is an RFID label with a printed DMC. While the DMC can be read directly on the object with a scanner, the RFID tag fulfills further tasks. Thanks to the special technology, goods can be identified even when packaged. In addition, all relevant process data can be stored on the RFID data carrier and offer added value throughout the value chain.

To learn more about RFID technology, please visit www.balluff.com.

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Not all IO-Link Masters are Born Equal!

IO-Link as a standard for device level communication has been around for over a decade. It has started gaining huge momentum in the Americas with 60-70% growth in IO-Link integration in 2017 alone (awaiting official numbers from the IO-Link consortium). Due to this huge market demand for IO-Link, there has been an insurgence of IO-Link masters with features and functionality that is dazzling machine builders and end users alike.

IO-Link Consortium Data (global)

While IO-Link as a communication platform is a standard (IEC 61131-9), the added features and functions leave some machine builders confused on how to reap benefits of these different masters that are around. Some machine builders have a thought process of “Hey, vendor A is selling an IO-Link master and vendor B is also selling an IO-Link master – they are both IO-Link so, why should I pay more?” These machine builders are choosing the lower cost options without realizing what they are missing out on – and sometimes getting disgruntled about the technology itself. On the other hand, some machine builders are spending too much time in measuring and testing a variety of masters – wasting precious time and materials to identify what fits best for their solution. With this blog post and my next, I am hoping to add some clarity on how to detect differences quickly amongst the masters and make a decision that is best suitable for the applications at hand.

IO-Link started out as a standard of communications for smart sensors with a focus to eliminate variety of different interfaces on the plant floor- but since its inception it has manifested itself to be much more than simple sensor integration. It has also gained significance as a backbone for enabling Industry 4.0 or IIoT.  So, let’s review different types of IO-Link masters.

The very first thing machine builders have to do is determine whether the IO-Link master should be IP20 (in cabinet) implementation or IP65-67-69 rated (machine mounted) implementation.

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The machine mounted version makes sense as it is suitable for most industrial environments. The IP20 version may be desirable if the machine is operating in extreme environments or experiences continuous changes in temperature, humidity and other factors.

With machine mount masters:

  • It is easier to debug the system with onboard diagnostics availability
  • Eliminates wiring and terminates hassle and saves time and money during the machine building process.

If the IP20 master is your choice, then there isn’t a major difference between vendor A and vendor B IO-Link masters. The difference could appear based on whether the IO-Link master is a part of a larger system or stand-alone module connected to the machine controller through one of the fieldbus or network gateway.  One more thing to note about IP20 masters is they are meant for connecting 3-pin IO-Link devices only. If you want to use architectural benefits of having added Vaux (separate output power) then using IP20 masters becomes complicated and quickly becomes expensive.

If the initial features of machine mounted masters are appealing to you, then there are a few more decisions to be made. The machine mounted IO-Link masters (for simplicity let’s call them IP67 Masters) range from “sensor only” integration capable masters to the ones that have the ability to become a backbone for flexible modular controls architecture. There are primarily three different types of masters as shown below in the chart and they differ based on the power routing capabilities and power handling capabilities.

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In my previous blog entry, “Demystifying Class A and Class B Type IO-Link Ports” I discussed the differences between Class A (Type A) and Class B (Type B) ports and the implications of each type.

We will go over more technical details in my next blog (part 2) to see how power routing and current capabilities make a difference between sensor only applications and a total architecture solution.

To learn more about IO-Link masters, visit www.balluff.com.

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Smart IO-Link Sensors for Smart Factories

Digitizing the production world in the age of Industry 4.0 increases the need for information between the various levels of the automation pyramid from the sensor/actuator level up to the enterprise management level. Sensors are the eyes and ears of automation technology, without which there would be no data for such a cross-level flow of information. They are at the scene of the action in the system and provide valuable information as the basis for implementing modern production processes. This in turn allows smart maintenance or repair concepts to be realized, preventing production scrap and increasing system uptime.

This digitizing begins with the sensor itself. Digitizing requires intelligent sensors to enrich equipment models with real data and to gain clarity over equipment and production status. For this, the “eyes and ears” of automation provide additional information beyond their primary function. In addition to data for service life, load level and damage detection environmental information such as temperature, contamination or quality of the alignment with the target object is required.

One Sensor – Multiple Functions

This photoelectric sensor offers these benefits. Along with the switching signal, it also uses IO-Link to provide valuable information about the sensor status or the current ambient conditions. This versatile sensor uses red light and lets you choose from among four sensor modes: background suppression, energetic diffuse, retroreflective or through-beam sensor. These four sensing principles are the most common in use all over the world in photoelectric sensors and have proven themselves in countless industrial applications. In production this gives you additional flexibility, since the sensor principles can be changed at any time, even on-the-fly. Very different objects can always be reliably detected in changing operating conditions. Inventory is also simplified. Instead of four different devices, only one needs to be stocked. Sensor replacement is easy and uncomplicated, since the parameter sets can be updated and loaded via IO-Link at any time. Intelligent sensors are ideal for use with IO-Link and uses data retention to eliminate cumbersome manual setting. All the sensor functions can be configured over IO-Link, so that a remote teach-in can be initiated by the controller.

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Diagnostics – Smart and Effective

New diagnostics functions also represent a key feature of an intelligent sensor. The additional sensor data generated here lets you realize intelligent maintenance concepts to significantly improve system uptime. An operating hours counter is often built in as an important aid for predictive maintenance.

The light emission values are extremely helpful in many applications, for example, when the ambient conditions result in increased sensor contamination. These values are made available over IO-Link as raw data to be used for trend analyses. A good example of this is the production of automobile tires. If the transport line of freshly vulcanized tires suddenly stops due to a dirty sensor, the tires will bump into each other, resulting in expensive scrap as the still-soft tires are deformed. This also results in a production downtime until the transport line has been cleared, and in the worst case the promised delivery quantities will not be met. Smart sensors, which provide corresponding diagnostic possibilities, quickly pay for themselves in such cases. The light remission values let the plant operator know the degree of sensor contamination so he can initiate a cleaning measure before it comes to a costly production stop.

In the same way, the light remission value BOS21M_ADCAP_Produktbild.png allows you to continuously monitor the quality of the sensor signal. Sooner or later equipment will be subject to vibration or other external influences which result in gradual mechanical misalignment. Over time, the signal quality is degraded as a result and with it the reliability and precision of the object detection. Until now there was no way to recognize this creeping degradation or to evaluate it. Sensors with a preset threshold do let you know when the received amount of light is insufficient, but they are not able to derive a trend from the raw data and perform a quantitative and qualitative evaluation of the detection certainty.

When it comes to operating security, intelligent sensors offer even more. Photoelectric sensors have the possibility to directly monitor the output of the emitter LED. This allows critical operating conditions caused by aging of the LED to be recognized and responded to early. In a similar way, the sensors interior temperature and the supply voltage are monitored as well. Both parameters give you solid information about the load condition of the sensor and with it the failure risk.

Flexible and Clever

Increasing automation is resulting in more and more sensors and devices in plant systems. Along with this, the quantity of transported data that has to be managed by fieldbus nodes and controllers is rising as well. Here intelligent sensors offer great potential for relieving the host controller while at the same time reducing data traffic on the fieldbus. Pre-processing the detection signals right in the sensor represents a noticeable improvement.  A freely configurable count function offers several counting and reset options for a wide variety of applications. The count pulses are evaluated directly in the sensor – without having to pass the pulses themselves on to the controller. Instead, the sensor provides status signals, e.g. when one of the previously configured limit values has been reached. This all happens directly in the sensor, and ensures fast-running processes regardless of the IO-Link data transmission speed.

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Industry 4.0 Benefits

In the age of Industry 4.0 and IoT, the significance of intelligent sensors is increasing. There is a high demand from end users for these sensors since these functions enable them to use their equipment and machines with far greater flexibility than ever before. At the same time they are also the ones who have the greatest advantage when it comes to preventing downtimes and production scrap. Intelligent sensors make it possible to implement intelligent production systems, and the data which they provide enables intelligent control of these systems. In interaction with all intelligent components this enables more efficient utilization of all the machines in a plant and ensures better use of the existing resources. With the increasing spread of Industry 4.0 and IoT solutions, the demand for intelligent sensors as data providers will also continue to grow. In the future, intelligent sensors will be a permanent and necessary component of modern and self-regulating systems, and will therefore have a firm place in every sensor portfolio.

To learn more about these smart sensors, visit www.balluff.com.

Posted in All posts, Industrial Internet of Things, Industrial Networking, IO-Link, Object Detection Sensors, Photoelectric Sensors | Tagged , , , , , , , , | 1 Comment

Inspection, Detection and Documentation – The Trifecta of Work in Process

As the rolling hills of the Bluegrass state turn from frost covered gold of winter to sun splashed green of spring, most Kentuckians are gearing up for “the most exciting two minutes in sports”, otherwise known as The Kentucky Derby. While some fans are interested in the glitz and glamour of the event, the real supporters of the sport, the bettors, are seeking out a big payday. A specific type of wager called a Trifecta, a bet that requires picking the first three finishers in the correct order, traditionally yields thousands, if not tens of thousands, of dollars in reward. This is no easy feat.  It is difficult to pick one horse, let alone three to finish at the top. So while the bettors are seeking out their big payday with a trifecta, the stakeholders in manufacturing organizations around the globe are utilizing the trifecta to ensure their customers are getting quality products. However, the trifecta of work in process is valued in millions of dollars.

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Work in process, or “WIP”, is an application within manufacturing where the product is tracked from the beginning of the process to the end. The overall goal of tracking the product from start to finish is, among other things, quality assurance. In turn, ensuring the product is of good quality creates loyal customers, prevents product recalls, and satisfies regulations. In a highly competitive manufacturing environment, not being able to ensure quality can be a death sentence for any organization. This is where the trifecta comes back into play. The three processes listed below, when used effectively together, ensure overall product quality and eliminate costly mistakes in manufacturing.

  1. Inspection – Typically executed withWorkinProcess Trifecta a vision system. Just like it sounds, the product is inspected for any irregularities or deviation from “perfect”.
  2. Detection – This is a result of the inspection. If an error is detected action must then be taken to correct it before it is sent to the next station or in some cases the product goes directly to scrap to prevent the investment of any additional resources.
  3. Documentation – Typically executed with RFID technology. The results of the inspection and detection process are written to the RFID tag. Accessing that data at a later time may be necessary to isolate specific component recalls or to prove regulatory compliance.

Whether playing the ponies or manufacturing the next best widget, the trifecta is a necessity in both industries. Utilizing a time tested system of vision and RFID technology has proven effective for quality assurance in manufacturing, but a reliable system for winning the trifecta in the derby is still a work in process.

To learn more about work in process, visit www.balluff.com.

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When to Use Hygienic Design vs. Washdown

Both washdown and hygienic design are common terms used in the food and beverage industry, and are increasingly being used in the packaging industry. These terms are used in different scenarios and easily confused with each other. What exactly are the differences between them, and in what applications are each used?

Why are hygienic design and washdown needed?

The consumer, and more specifically, the health of the consumer is the core concern of the food and beverage industry. Contaminated food can pose a danger to life and limb. A product recall damages the image of a company, costs a lot of money and as a worst case scenario can lead to the complete closing of the company. To prevent such scenarios, a producers primary objective is to make sure that the food is safe and risk-free for the consumer.image 1

In food manufacturing and packaging plants, a differentiation is made between the food area (in direct contact with the product), the spray area (product-related) and the non-food area. The requirements of the machine components are different depending on which area they are in.

The Food Area

In the food area the food is unpacked, or partially unpacked, and particularly susceptible to contamination. All components and parts that may come in contact with the food must not adversely affect this, e.g. in terms of taste and tolerability.

The following needs to be considered to avoid contamination:

  • Hygiene in production
  • Use of food contact materials
  • Food-grade equipment in Hygienic Design

These requirements result in the need for components that follow the hygienic design rules. If the component supplier fulfills these rules, the machine manufacturer can use the components and the producer can use the machines without hesitation.

Hygienic Design

Many component suppliers offer different solutions for hygienic design and each supplier interprets the design differently. So what does hygienic design mean? What must be included and which certifications are the right ones?

  • The material used must be FoodContact Material (FCM). This means that the material is non-corrosive, non-absorbent and non-contaminating, disinfectable, pasteurisable and sterilizable.
  • Seals must be present to prevent the ingress of microorganisms.
  • The risk of part loss must be minimized.
  • Smooth surfaces with a radius of < 0.8 μm are permitted.
  • There must be no defects, folds, breaks, cracks, crevices, injection-molded seams, or joints, even with material transitions.
  • There must be no holes or depressions and no corners of 90°.
  • The minimum radius should be 3 mm.

Supporting institutions and related certifications

There are different institutions which confirm and verify the fulfillment of these rules. They also support the companies during the development process.

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EHEDG – The European Hygienic Engineering and Design Group offers machine builders and component suppliers the possibility to evaluate and certify their products according to Hygienic Design requirements.

image33A – 3-A Sanitary Standards, Inc. (3-A SSI) is an independent, non-profit corporation in the U.S. for the purpose of improving hygiene design in the food, beverage and pharmaceutical industries. The 3-A guidelines are intended for the design, manufacture and cleaning of the daily food           accessories used in handling, manufacturing and packaging of edible products with high hygiene requirements.

image4FDA – The Food and Drug Administration is a federal agency of the United States Department of Health and Human Services, one of the United States federal executive departments. Among other things, the FDA is responsible for food safety.

What does a hygienic design product look like?

Below is an example of a hygienic design product.

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  • Stainless steel housing VA 1.4404
  • Laser marking
  • Protection class IP69K (IEC 60529)
  • Active surface made of PEEK
  • EHEDG conform
  • FDA conform

Since the product contacting area is associated with high costs for the plant manufacturer and the operator, it’s beneficial to keep it as small as possible.

The Spray Area

In the spray area, there are different requirements than in the food area.
Depending on the type of food that is processed, a further distinction is made between dry and wet areas.

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Areas in the food and beverage production

Here we are talking about the washdown area. Washdown capable areas are designed for the special environmental conditions and the corresponding cleaning processes.

Washdown

Components which fulfill washdown requirements usually have the following features:

  • Cleaning agent/corrosion resistant materials (often even food compliant, but this is not a must)
  • High protection class (usually IP 67 and IP 69K)
  • Resistant to cleaning agents
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Photoelectric sensor for washdown requirements

Ecolab and Diversey are two well-known companies whose cleaning agents are used for appropriate tests:

Ecolab Inc. and Diversey Inc. are US based manufacturers of cleaning agents for the food and beverage industry. Both companies offer certification of equipment’s resistance to cleaning agents. These certificates are not prescribed by law and are frequently used in the segments as proof of stability.

The washdown component must also be easy and safe to clean. However, unlike the hygienic design, fixing holes, edges and threads are permitted here.

For basic information on IP69K see also this previous blog post.

To learn more about solutions for washdown and hygienic design click here.

 

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The Perfect Photoelectric Sensor – Imagine No More

In my last blog, Imagine the Perfect Photoelectric Sensor, I discussed the possibilities of a single part number that could be configured for any of the basic sensing modes: through-beam, retroreflective, background suppression and diffuse. This perfect sensor would also have the ability to change the sensing mode on the fly and download the required parameters for a changing process or format change.  Additionally, it would have the ability to teach the sensing switch points on the fly, change the hysteresis, and have variable counter and time delays.

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Tomorrow is here today! There is no need to imagine any longer, technology has taken another giant leap forward in the photoelectric world.  Imagine the possibilities!

Below are just some of the features of this leading edge technology sensor. OEM’s now have the opportunity to have one sensor solve multiple applications.  End users can now reduce their spare inventory.

To learn more visit www.balluff.com.

 

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Increase Competitiveness with RFID in the Intralogistics Industry

In times of globalization and high labor costs it is a challenge to increase competitiveness in the fashion industry. Within a warehouse, an RFID system supports a high degree of automation as well as short transport distances. To supply dealers and to keep their facility profitable, one of the most successful fashion companies in the world has built a highly modern hanging garment distribution center. Let’s take a look at how they successfully implemented RFID technology to improve their processes.

Separate and sort clothes with just one hybrid module (2D code + RFID)

Within this distribution center 45,000 of these innovative clothes hanger adapters (L-VIS) are used. They replace the previous trolley-based logistics approach by allowing the transportation of a number of different garments that have the same destination.

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L-VIS, clothes hanging adapter made by P.E.P. Fördertechnik

With the investment in some additional space in the so-called buffer or storage zone, and by providing empty trolleys at various locations to keep the product flow moving, this project is successfully accomplished. A major advantage of this system, is the usability over the entire intralogistics chain. From receiving, to the hanging storage, to the sorter for single item identification, and from there as a transport unit to shipping.

The clothes hanger contains an RFID chip, that is automatically read by the conveying technology, and the 2D-code. This code is read manually by employees with a portable acquisition unit. The code can be DMC (Data Matrix Code), QR-Code, or any other optical code standard.

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HUGO BOSS garment distribution center (Metzingen, Germany)

Information exchange without visual contact

A high frequency RFID chip is installed. With this identification system, neither direct alignment nor contact is needed to enable data exchange via nearfield communication. Non-contact identification is extremely reliable and wear-free. The identification system consists of a rugged data carrier, a read/write head and an RFID processor unit. The processor unit communicates to the control system via Profibus, but could be accomplished with ProfiNet or EtherNet/IP as well.

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BIS-M RFID processor unit

The following table gives you an overview of types of Radio Frequency Identification solutions that are available on the market:

Common Types Low Frequency Low Frequency High Frequency Ultra High Frequency
Frequency 70/455 kHz 125 kHz 13.56 MHz 860 … 960 MHz
Short description Dedicated solution to tool identification in Metal-Working industry. Standard solutions for simple Track & Trace applications. Fast & reliable – even with high volumes of data in medium distances in assembly, production and intralogistics. Identification at large distances and bunching capability for current material flow concept.

For the customer, the decision to choose this particular system among others was the separation between the processor and read/write head. In a widespread facility it would not make sense to have a decoder with 30 read/write heads attached. By interfacing two read/write heads per processor, it is possible to track the travel of a transport unit over the entire conveyor line as well as track within the aisles between the individual shelves.

An additional advantage of the system implemented is the housing options. The L-VIS carrier and the 30 mm read/write head are an ideal match. The simple mounting of the processors and ready-to-use connection were of high value to the system integrators. In the sorting area, a 2D code was supplemented by the RFID tags to reach speeds of up to 0.6 and 0.7 m/s. This would probably not have been possible with the installation of a corresponding camera technology.

Experiences have shown, that RFID projects need a lot of support. Consultation and assistance from true experts can be provided by our team. Learn more about RFID technology here.

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An Easy Way to Remember PNP and NPN Sensor Wiring

Here’s a simple way remember how to wire up a 3-wire DC PNP or NPN sensor:

PNP = Switched Positive

NPN = Switched Negative

“Switched” refers to which side of the controlled load (relay, small indicator, PLC input) is being switched electrically. Either the load is connected to Negative and the Positive is switched (PNP), or the load is connected to Positive and the Negative is switched (NPN). These diagrams illustrate the differences between the two connections.

Click here for more information about the Basics of Automation.

2.14.2018_PNP v NPN Graphic

 

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