Mobile Equipment Manufacturers: Is It Time to Make the Switch to Inductive Position Sensors?

Manufacturers of mobile equipment are tasked with the never-ending pursuit of making their machines more productive while adhering to the latest safety regulations, and all at less cost. To help achieve these goals, machines today use electronic control modules to process inputs and provide outputs that ultimately control the machine functions. Yet with all the changes in recent years, one component left over from that earlier era remains in regular use — the mechanical switch.  Switches offered a variety of levers, rollers, and wands for actuation, and many were sealed for an IP67 rating for outdoor use, but they came with an array of problems, including damaged levers, contact corrosion, arcing concerns, dirt or grain dust ingress, and other environmental hazards. Still, overall they were an acceptable and inexpensive way to receive position feedback for on/off functions.

Today, mechanical switches can still be found on machines used for boom presence, turret location, and other discrete functions. But are they the right product for today’s machines?

The original design parameters may have required the switch to drive the load directly, and therefore a rating of 10A@240V might be a good design choice for the relay/diode logic circuits of the past. But a newly designed machine may be switching mere milliamps through the switch into the control module. Does the legacy switch have the proper contact plating material for the load today? Switches use rare metals such as rhodium, palladium, platinum, gold, and silver in attempts to keep the contact resistance low and to protect those contacts from corrosion. Consequently, as China pursues Nonroad Stage IV standards, these metals, some also used in catalytic converters, have sharply increased in price, leading to substantial cost increases to switch manufacturers and ultimately switch users.

A better approach to position feedback for today’s mobile machines is the inductive position sensor. Inductive sensors offer a sealed, non-contact alternative to mechanical switches. Sensing ferrous and non-ferrous metals without physical contact, they eliminate many of the field problems of the past, and non-metallic substances such as water, dirt, and grain dust, do not affect the operation. These qualities make the sensor very suitable for the harsh conditions found in agricultural and construction environments.

Inductive proximity sensors come in a variety of form factors:

Threaded cylindrical – With zinc-plated brass or stainless-steel housings, the threaded barrel styles are popular for their ease of mounting and gap adjustment.  

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Low profile rectangular – These “flatpack” style sensors are great under seats for operator presence.

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Block designs – The compact, cubed package is ideal for larger sensing ranges.

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Large cylindrical – These large “pancake” style sensors are great for detecting suspension movements and other applications requiring extreme ranges.

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Inductive position sensors are more than just a discrete product used for detecting linkage, operator presence, or turret stops; They can also perform the duties of a speed sensor by counting teeth (or holes) to determine the RPM of a rotating shaft. Other models offer analog outputs to provide a continuous feedback signal based on the linear location of a metal linkage or lever. Safety rated outputs, high temperatures, and hazardous area options are some of the many product variants available with this electromagnetic technology.
So, perhaps it’s time to review that legacy switch and consider an inductive sensor?
To learn how an inductive position sensor performs its magic, please take a look at an earlier blog:

Basic Operating Principle of an Inductive Proximity Sensor

Error Proof Stamping Applications with Pressure Sensors

When improving product quality or production efficiency, manufacturing engineers typically turn to automation solutions to error proof and improve their application. In stamping applications, that often leads to adding sensors to help detect the presence of a material or a feature in a part being formed, for example, a hole in a part. In the stamping world, this can be referred to as “In-Die Sensing” or “Die Protection.” The term “Die Protection” is used because if the sensors do not see the material in the correct location when forming, then it could cause a die crash. The cost of a die crash can add up quickly. Not only is there lost production time, but also damage to the die that can be extremely costly to repair. Typically, several sensors are used throughout the die to look for material or features in the material at different locations, to make sure the material is present to protect the die. Manufacturing engineers tend to use photoelectric and/or inductive proximity sensors in these applications; however, pressure sensors are a cost-effective and straightforward alternative.

In today’s stamping applications, manufacturing engineers want to stamp parts faster while reducing downtime and scrap. One growing trend in press shops is the addition of nitrogen on the dies. By adding nitrogen-filled gas springs and/or nitrogen gas-filled lifters, the press can run faster and cycle parts through quicker.

Typically, the die is charged with nitrogen before the press starts running parts. Today, many stamping plants rely on an analog dial gauge (image 1) to determine if there is sufficient nitrogen pressure to operate safely. When a new die is set in the press, someone must look at the gauge and make sure it is correct before running the press. There is no type of signal or feedback from this gauge to the PLC or the press; therefore, no real error proofing method is in place to notify the operator if the pressure rating is correct or even present before starting the press. If the operator starts running the press without any nitrogen for the springs, then it will not cycle the material and can cause a crash.

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Another, likely more significant problem engineers face is a hole forming in one of the hoses while they are running. A very small hole in a hose may not be noticeable to the operator and may not even show up on the analog dial gauge. Without this feedback from the gauge, the press will continue to run and increase the likelihood that the parts will be stamped and be out of specification, causing unnecessary scrap. Scrap costs can be quite large and grow larger until the leak is discovered. Additionally, if the material cannot move through the press properly because of a lack of nitrogen pressure to the springs or lifters, it could cause material to back up and cause a crash.

By using a pressure sensor, you can set high and low pressure settings that will give an output when either of those is reached. The outputs can be discrete, analog, or IO-Link, and they can be tied to your PLC to trigger an alarm for the operator, send an alert to the HMI, or even stop the press. You can also have the PLC make sure pressure is present before starting the press to verify it was adequately charged with nitrogen during set up.

Adding an electronic pressure sensor to monitor the nitrogen pressure is a simple and cost-effective way to error proof this application and avoid costly problems.

How Cameras Keep Tire Manufacturers From Spinning Their Wheels

Tires being transported between the curing presses and the staging area before their final inspection often become clustered together. This jam up can cause imperfections to the tires and damage to the conveyors. To alleviate this problem, some tire manufacturers have installed vision systems on their conveyors to provide visual feedback to their production and quality teams, and alert them when the tires start to get too close together.

A vision system can show you alerts back in your HMI by using inputs and outputs built into the camera or use an IO-Link port on the camera to attach a visual display, for example a SmartLight with audible and flashing alerts enabled. Once you see these alerts, the PLC can easily fix the issue from the program or a maintenance worker or engineer can quickly respond to the alert.

Widespread use of smart vision cameras with various pixel options has become a trend in tire manufacturing. In additional to giving an early alert to bunching problems, vision systems can also capture pictures and data to verify that tires were cleared all the way into final inspection. Although tire machine builders are being asked to incorporate vision systems into their machines during the integration process, it is more likely for systems to be added in plants at the application level.

Vision systems can improve production throughput, quality issues and record production data about the process for analytics and analysis down the road. Remember a tire plant usually consists of these processes in their own large section of the plant and involves many machines in each section:

  • Mixing
  • Tire Prep
  • Tire Build
  • Curing
  • Final Inspection

Each one of these process areas in a plant can benefit from the addition of vision systems. Here are a few examples:

  • Mixing areas can use cameras as they mill rubber and detect when rubber sheets are off the rollers and to look for engraved information embedded in the rubber material for logistics and material flow to the proper processes.
  • Tire Prep can use cameras to ensure all the different strand colors of steel cords are embedded or painted on the rubber plies before going to tire build process.
  • Tire Build can use vision to detect the side-wall beads are facing the right direction and reading the embedded position arrows on the beads before tire plies are wrapped around them.
  • Curing area can use vision to monitor tire clusters on conveyors and make sure they are not too close to each other by using the measuring tool in the camera software.
  • Final Inspection can use vision to read barcodes, QR codes, detect colors of embossed or engraved serial numbers, detect different color markings and shape of the markings on the tire.

The use of machine vision systems can decrease quality issues by pinpointing errors before they make it through the entire production process without detection.

Top 5 Insights from 2019

With a new year comes new innovation and insights. Before we jump into new topics for 2020, let’s not forget some of the hottest topics from last year. Below are the five most popular blogs from our site in 2019.

1. How to Select the Best Lighting Techniques for Your Machine Vision Application

How to select the best vision_LI.jpgThe key to deploying a robust machine vision application in a factory automation setting is ensuring that you create the necessary environment for a stable image.  The three areas you must focus on to ensure image stability are: lighting, lensing and material handling.  For this blog, I will focus on the seven main lighting techniques that are used in machine vision applications.

READ MORE>>

2. M12 Connector Coding

blog 7.10_LI.jpgNew automation products hit the market every day and each device requires the correct cable to operate. Even in standard cables sizes, there are a variety of connector types that correspond with different applications.

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3. When to use optical filtering in a machine vision application

blog 7.3_LI.jpgIndustrial image processing is essentially a requirement in modern manufacturing. Vision solutions can deliver visual quality control, identification and positioning. While vision systems have gotten easier to install and use, there isn’t a one-size-fits-all solution. Knowing how and when you should use optical filtering in a machine vision application is a vital part of making sure your system delivers everything you need.

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4. The Difference Between Intrinsically Safe and Explosion Proof

5.14_LIThe difference between a product being ‘explosion proof’ and ‘intrinsically safe’ can be confusing but it is vital to select the proper one for your application. Both approvals are meant to prevent a potential electrical equipment malfunction from initiating an explosion or ignition through gases that may be present in the surrounding area. This is accomplished in both cases by keeping the potential energy level below what is necessary to start ignition process in an open atmosphere.

READ MORE>>

5. Smart choices deliver leaner processes in Packaging, Food and Beverage industry

Smart choices deliver leaner processes in PFB_LI.jpgIn all industries, there is a need for more flexible and individualized production as well as increased transparency and documentable processes. Overall equipment efficiency, zero downtime and the demand for shorter production runs have created the need for smart machines and ultimately the smart factory. Now more than ever, this is important in the Packaging, Food and Beverage (PFB) industry to ensure that the products and processes are clean, safe and efficient.

READ MORE>>

We appreciate your dedication to Automation Insights in 2019 and look forward to growth and innovation in 2020!

 

 

The Benefits of Guided Changeover in Packaging

Today’s consumer packaged goods (CPG) market is driving the need for greater agility and flexibility in packaging machinery.  Shorter, more customized runs create more frequent machine changeover.  Consequently, reducing planned and unplanned downtime at changeover is one of the key challenges CPG companies are working to improve.

Many packaging machine builders are now providing fully automated changeover, where motors move pieces into the correct position upon recipe change.  This has proven to be a winning solution, however, not every application can accommodate motors, especially those on older machines.

Guided changeover represents an opportunity to modify or retrofit existing equipment to improve agility and flexibility on older machines that are not yet ready to be replaced.

An affordable intermediate step between fully manual and fully automated changeover: 

A measurement sensor can be added to provide position feedback on parts that require repositioning for changeover.  By using indicator lights, counters or displays at the point of use, the operator is provided with visual guidance to reposition the moving part.  Only once all parts are in the correct position can the machine start up and run.

By utilizing this concept, CPG companies can realize several key benefits:

  • Reduced planned downtime: Adding guidance reduces the amount of time it takes to move parts into the correct position.
  • Reduced unplanned downtime: Providing operator guidance minimizes mistakes, avoiding jams and other problems caused by misalignment.
  • Reduced waste: Operators can “dial in” moving parts quickly and precisely.  This allows the machine to be fully operational sooner, minimizing runoff and scrap.
  • Improved operator training: Providing operator guidance helps CPG companies deal with inevitable workforce attrition.  New operators can be quickly trained on changeover procedures.

Selecting the correct sensor

A variety of sensor technologies can be used to create guide changeover; it’s really a matter of fit, form and function.  Common technologies used in changeover position applications include linear positioning transducers  and encoders.  Other devices like inductive and photoelectric distance sensors can be used with some creativity to solve challenging applications.

Available mounting space and environmental conditions should be taken into consideration when selecting the correct device.  Sensors with enhanced IP ratings are available for harsh environmental conditions and washdown.

Analog devices are commonly used to retrofit machines with older PLCs, while IO-Link can be used in place of analog for a fully digital solution, enabling bi-directional communication between the sensor and controller for condition monitoring, automatic device replacement and parameter changes.

Using MicroSpot LEDs for Precise Evaluations in Life Science

Handling microfluidics and evaluating samples based on light is a precise science. And that precision comes from the light source, not the actual detection method. But too many times we see standard LEDs being used in these sensing and evaluation applications. Standard LEDs are typically developed for lighting and illumination applications and require too many ancillary components to achieve a minimum level of acceptability. Fortunately, there is an alternate technology.

First, let’s look at a standard LED. Figure 1 shows a typical red LED. You can see the light emission surface is cluttered with the anode pad (square in the middle) and its bond wire. These elements are fine for applications like long-range sensing, lighting and indications, but for precise, up-close applications they cause disturbances.

Figure 1: Typical red LED showing the intrusion of the anode and bond wire into the light emission

Most notable is the square hole in the middle of the emission pattern. There are two typical methods to reduce the effect of the hole: lensing and apertures. An aperture essentially restricts the emitted light to a corner of the die, substantially reducing the light energy causing difficulties with low-contrast detections. Using a lens only will maintain the light energy, but the beam will have a fixed focused point that is not acceptable for many applications. But even the bond wire produces reflections and causes spurious emissions. These cannot be tolerated with microfluidics as adjacent channels will become involved in the measurement. An additional aperture is typically used to suppress the spurious emissions.

Fortunately, there is an alternative with MicroSpot LEDs. Basically, the anode and emission areas are inverted as shown in the Figure 2 comparison.

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Figure 2: Comparison of the typical LED with the MicroSpot’s clean, powerful and collimated emission

This eliminates the need for the anode and bond wire to interfere with the emitted light. This produces a clean, powerful and collimated emission that will produce consistent results without additional components. This level of beam control is typically reserved for lasers. However, lasers also require more components, are much larger and cost more. The MicroSpot LED is the best choice for demanding life science applications.

Try the MicroSpot for yourself in select Balluff MICROmote miniature photoelectric sensors.

Learn more at www.balluff.com.

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.

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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.

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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.

Improve Your Feeder Bowl System (and Other Standard Equipment) with IO-Link

One of the most common devices used in manufacturing is the tried and true feeder bowl system. Used for decades, feeder bowls take bulk parts, orients them correctly and then feeds them to the next operation, usually a pick-and-place robot. It can be an effective device, but far too often, the feeder bowl can be a source of cycle-time slowdowns. Alerts are commonly used to signal when a feed problem is occurring but lack the exact cause of the slow down.

feeder bowl

A feed system’s feed rate can be reduced my many factors. Some of these include:

  • Operators slow to add parts to the bowl or hopper
  • Hopper slow to feed the bowl
  • Speeds set incorrectly on hopper, bowl or feed track
  • Part tolerance drift or feeder tooling out of adjustment

With today’s Smart IO-Link sensors incorporating counting and timing functions, most of the slow-down factors can be easily seen through an IIoT connection. Sensors can now time how long critical functions take. As the times drift from ideal, this information can be collected and communicated upstream.

A common example of a feed system slow-down is a slow hopper feed to the bowl. When using Smart IO-Link sensors, operators can see specifically that the hopper feed time is too long. The sensor indicates a problem with the hopper but not the bowl or feed tracks. Without IO-Link, operators would simply be told the overall feed system is slow and not see the real problem. This example is also true for the hopper in-feed (potential operator problem), feed track speed and overall performance. All critical operations are now visible and known to all.

For examples of Balluff’s smart IO-Link sensors, check out our ADCAP sensor.

How flexible inspection capabilities help meet customization needs and deliver operational excellence

As the automotive industry introduces more options to meet the growing complexities and demands of its customers (such as increased variety of trim options) it has rendered challenges to the automotive manufacturing industry.

Demands of the market filter directly back to the manufacturing floor of tier suppliers as they must find the means to fulfill the market requirements on a flexible industrial network, either new or existing. The success of their customers is dependent on the tier supplier chain delivering within a tight timeline. Whereby, if pressure is applied upon that ecosystem, it will mean a more difficult task to meet the JIT (just in time) supply requirements resulting in increased operating costs and potential penalties.

Meeting customer requirements creates operational challenges including lost production time due to product varieties and tool change time increases. Finding ways to simplify tool change and validate the correct components are placed in the correct assembly or module to optimize production is now an industry priority. In addition, tracking and traceability is playing a strong role in ensuring the correct manufacturing process has been followed and implemented.

How can manufacturing implement highly flexible inspection capabilities while allowing direct communication to the process control network and/or MES network that will allow the capability to change inspection characteristics on the fly for different product inspection on common tooling?

Smart Vision Inspection Systems

Compact Smart Vision Inspection System technology has evolved a long way from the temperamental technologies of only a decade ago. Systems offered today have much more robust and simplistic intuitive software tools embedded directly in the Smart Vision inspection device. These effective programming cockpit tools allow ease of use to the end user at the plant providing the capability to execute fast reliable solutions with proven algorithm tools. Multi-network protocols such as EthernetIP, ProfiNet, TCP-IP-LAN (Gigabit Ethernet) and IO-LINK have now come to realization. Having multiple network capabilities delivers the opportunity of not just communicating the inspection result to the programmable logic controller (via process network) but also the ability to send image data independent of the process network via the Gigabit Ethernet network to the cloud or MES system. The ability to over-lay relevant information onto the image such as VIN, Lot Code, Date Code etc. is now achievable.  In addition, camera housings have become more industrially robust such as having aluminum housings with an ingress protection rating of IP67.

Industrial image processing is now a fixture within todays’ manufacturing process and is only growing. The technology can now bring your company a step closer to enabling IIOT by bringing issues to your attention before they create down time (predictive maintenance). They aid in reaching operational excellence as they uncover processing errors, reduce or eliminate scrap and provide meaningful feedback to allow corrective actions to be implemented.

Zone Defense: How to Determine If You Need a Hygienic or Washdown Solution

It goes without saying that food safety is an extremely important aspect of the food and beverage industry. While manufacturers would naturally take precautions to ensure their food products are safe to consume, they are required to follow a set of rigid guidelines and standards to ensure the safety of the foodstuffs to prevent contamination.

CaptureTo determine which rating, standards or certifications are required for a particular food and beverage segment, you must first consider the type of food contact zone and whether it is an open or closed process.

Food Contact Zones

The food contact zone is determined by the potential contamination that can occur based on the production equipment’s exposure to food and its byproducts.

  • Food Zone: an area intended to be exposed to direct contact with food or surfaces where food or other substances may contact and then flow, drain or drain back onto food or food contact surfaces.
  • Splash Zone: an area that is routinely exposed to indirect food contact due to splashes and spills. These areas are not intended for contact with consumable food.
  • Nonfood Zone: An area that is not exposed to food or splashes but will likely be exposed to minor dirt and debris.

Open and Closed Production

In the food and beverage industry, it is also important to discuss whether the manufacturing process is open or closed. The distinction between the two plays a significant role in determining machine cleaning requirements.

  • Closed Process: A manufacturing operation in which the food product never comes in contact with the environment. All food contact zones are sealed such as the inner surfaces of tanks, pipelines, valves, pumps and sensors.
  • Open Process: A manufacturing operation in which food does have contact with the environment outside of the machine. This requires a hygienic design of the process environment, as well as the surfaces of the apparatus and components.

Required ratings, standards and certifications

Once you know the food zone and whether the production is open or closed, it becomes simple to determine which ratings, standards or certifications are required of the machinery and apparatus in the food and beverage manufacturing process.

  • Food Contact Zone — Hygienic
    • IP69K – tested to be protected from high pressure steam cleaning per DIN40050 part 9
    • FDA – made of FDA approved materials, most often 316L stainless steel
    • 3-A – certified sanitary and hygienic equipment materials and design in the US
    • EHEDG – certified sanitary and hygienic equipment materials and design in Europe
  • Food Splash Zone — Washdown
    • IP69K – tested to be protected from high pressure steam cleaning per DIN40050 part 9
    • ECOLAB – surfaces tested to be protected from cleaning and disinfecting agents
  • Nonfood Zone — Factory Automation
    • IP67 – rated for water immersion up to a meter deep for half an hour
    • IP65 – rated as dust tight and protected against water projected from a nozzle

For more information on the requirements of the food and beverage industry, visit www.balluff.com.