Inductive coupling – simple concept for complex automation

Inductive coupling is not new to automation. The concept in various forms has been around for over few decades. It was not actively used, and my guess is that more than form factor or functionality of couplers, it has to do with automation technology relying on mechanical and hard wired components. With growing complexity and ever evolving technology, the inductive coupling has also evolved.  Nowadays, you can charge your smart phones or tablets using the charging pad that uses the very same technology.

power&dataexchange
Figure 1: Inductive coupling for power and data exchange

In industrial automation space, inductive sensors are very popular and commonly used for detecting proximity of metal objects such as food cans, or machine parts. Inductive coupling uses magnetic induction to transfer power and data over an air gap. Yes, it is a kind of very short range wireless technology that also enables power transfer.

SlipRing
Figure 2: Slip ring example

In this series of blogs on inductive coupling, we can explore various use cases of inductive coupling in complex automation. Today, let’s see how inductive coupling compares with traditional slip-ring mechanism.

Slip-rings, also known as rotary connectors, are typically used in areas of the machine where one part rotates and other part of the machine remains stationary. For example, an indexing table or turn table where stations on the indexing table need power and I/O but the table rotates through full 360°, hence standard cable solutions are ineffective. A slip ring could be installed at the base of the table.

ReplacingSlipRing
Figure 3: Inductive coupling replacing the slip-ring

Since, slip rings are electromechanical devices, in the long term they are subject to wearing out. Unfortunately, the signs of wear are not evident unless one day there is no power to the table. An inductive coupling solution eliminates all the hassle of the mechanical parts. With non-contact inductive coupling, the base coupler could be mounted at the base of the table and the remote coupler could be mounted on the rotating part of the table. Slip rings are susceptible to noise and vibration because they are electromechanical devices, whereas inductive couplers are not because there is no contact between the base and the remote.  In fact, the turn table shown above uses an inductive coupler.

Inductive coupler, typically have IP67 rating for the housing are not affected by dirt or water, are immune to vibrations, and most important they are contact free so no maintenance is required unless you hammer one out. Learn more about Balluff inductive couplers: www.balluff.us.

5 Tips on Making End-of-Arm Tooling Smarter

Example of a Flexible EOA Tool with 8 sensors connected with an Inductive Coupling System.

Over the years I’ve interviewed many customers regarding End-Of-Arm (EOA) tooling. Most of the improvements revolve around making the EOA tooling smarter. Smarter tools mean more reliability, faster change out and more in-tool error proofing.

#5: Go Analog…in flexible manufacturing environments, discrete information just does not provide an adequate solution. Analog sensors can change set points based on the product currently being manufactured.

#4: Lose the weight…look at the connectors and cables. M8 and M5 connectorized sensors and cables are readily available. Use field installable connectors to help keep cable runs as short as possible. We see too many long cables simply bundled up.

#3: Go Small…use miniature, precision sensors that do not require separate amplifiers. These miniature sensors not only cut down on size but also have increased precision. With these sensors, you’ll know if a part is not completely seated in the gripper.

#2: Monitor those pneumatic cylinders…monitoring air pressure in one way, but as speeds increase and size is reduced, you really need to know cylinder end of travel position. The best technology for EOA tooling is magnetoresistive such as Balluff’s BMF line. Avoid hall-effects and definitely avoid reed switches. Also, consider dual sensor styles such as Balluff’s V-Twin line.

#1: Go with Couplers…with interchangeable tooling, sensors should be connected with a solid-state, inductive coupling system such as Balluff’s Inductive Coupler (BIC). Avoid the use of pin-based connector systems for low power sensors. They create reliability problems over time.

Rise of the Robots – 3 Ways to Be On Their Team

While originally a mixed reviewed 1994 console video game, the recently published report by The Boston Consulting Group titled “The Rise of Robotics”  really made me realize how important it is that we embrace robotics in our manufacturing processes.  And I strongly agree with this statement: “Because robots can sharply improve productivity and offset regional differences in labor costs and availability, they’ll likely have a major impact on the competitiveness of companies and countries alike.”  They studied the growth of the usage of robots in personal, commercial, military and industrial use and the numbers were quite powerful.  Of interest to me is the rise in industrial robotics; doubling in 5 years from $5.8b to $11.0b in 2015.  And the growth is expected to more than double again by 2025 to $24.4b in the industrial space.

What this means for manufacturers, machine builders and component suppliers is we need to make sure our people are trained to support this growth and that we we have strong peripheral technologies to support robots as they grow and expand.  Even today there are some great technologies available in sensors and controls that make robotic integration easier for manufacturing companies.

So here are the three ways to make sure you are your robot’s ally.

  1. Maximize Their Payload!

    No one wants to be treated like they can’t help… especially your robots, they want you to utilize them and feel appreciated.  For most robotics right now, payload size & payload weight is a limiting factor.  Mini sensing products with precision switch points, small form factors and low mass allow for the design of low weight, compact payloads without limiting the functionality or speed of the robot.

  2. Keep them Working!

    A working robot is a happy robot.  By adding flexible tooling or quick-change tooling to the end-effector of a robot you can have one arm perform multiple functions and keep idle arms to a minimum, increasing their value and “happiness.”  Multiple products are out there to allow for this, however there is a technology that allows for sensor connections through inductive coupling that dramatically decreases repair issues and downtime due to tool changer pins.

  3. Remove the Chains!  

    What’s the deal with cable dress packs… they look like really bad suspenders sometimes… you see them, you don’t like how they look, but you need it to keep your pants on… I guarantee that robots don’t like these things either… And with all that flexing something in there will fail regularly.  There are some great technologies to reduce the sensor cables running on the arm and add flexibility and they are supported by the open standard IO-Link (discussed in other posts here!).

So as you integrate robots more and more into the manufacturing we are doing, please start thinking how to align yourself as a robot’s ally.  Because I know I want to be on this guy’s team…

Sacrificing for the Greater Good

Environments with debris and caustic agents, wear down equipment exponentially. When a cell goes down, every minute counts to get production up and running.  An accessory like a cordset is important for operations, and can frustrate technicians when it fails. Cordsets do not last forever in this environment and to help save money, time and work, we came up with the concept of a “sacrificial cable.” The basic idea is to install a double-ended cable under 2 meters to help in situations where cables are placed in surroundings which will destroy the cable.  A sacrificial cable’s main function is to save time reducing cable replacement downtime and money.

Sacrifice Cordset Solution: Used in extremely rugged applications to reduce cordset replacement downtime

hrcable

A sacrificial cable does not have to be a specialty cable with a custom jacket; it could just be a 1 meter PVC cable that will get changed out often. The idea is that by placing a sacrificial cable in a problematic area and connecting it to a longer length cable this will allow maintenance to have a shorter down time when changing out failures less.  This is accomplished with travel around the cell following a cable run and less maintenance expense in labor.

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Back to the Basics on Receptacles – Part 2

In a previous post, I talked about receptacles for automation equipment.  But there are many different types of mounting when it comes to receptacles.  When picking a mounting type, it is based on preference.  Each type of mounting has its good points.  Depending on what else is inside the cabinet, might sway which mounting is preferred.

r2_1A popular mounting is front mounting.  Front mounting comes into the panel from the outside of the control cabinet and is secured with lock (jamming) nut on the inside of the cabinet and sealed with an o-ring on the outside of the cabinet (figure to the right).  The o-ring with the lock nut gives the receptacle a tight seal to keep out dust and moisture.  It is one of the easier receptacles to replace since it is installed from the outside of the cabinet.

r2_2Another mounting type is back mounting.   With a back mounting, the threads are on the connector part of the receptacle.  Back mounting is the opposite of the front mounting with the o –ring and jamming nut on the outside of the cabinet.  A back mounting receptacle takes some preplanning.  The receptacle should go into the control cabinet first to make sure there is room for the other components in the cabinet like a power source, PLC or terminals.  If the receptacle needs replaced, then it might require some of the components in the cabinet to be removed to have enough room to remove the receptacle.

Continue reading “Back to the Basics on Receptacles – Part 2”

The Spring Line is Here!

In today’s industrial market, Ethernet cable is in high demand. With words like Ethernet, Ethernet/IP, solid, and stranded, making a decision from the different types of cable can be difficult.

I want to make it easy for you to pick the right cable to go with the network of your choosing.  As a network, Ethernet is easy to install and it is easy to connect to other networks – you can probably even have Ethernet network devices connect to your current network.

So, let’s start with the basics…First, what is the difference between Ethernet and Ethernet/IP?  They both have teal jackets (hence the title – The “Spring Line”) due to the industrial Ethernet standards in North America. So, the difference between the two is in the application.  Ethernet is a good networking cable that transmits data like an internet cable.  Ethernet/IP transmits data and also has an industrial protocol application.  The Industrial Protocol (IP) allows you to transmit more data if you have a lot devices connected to each other or a lot of machines moving at once.  Ethernet/IP resists against UV rays, vibrations, heat, dust, oil, chemical, and other environmental conditions.

Next, there are two kinds of Ethernet IP cables: Solid and Stranded. Solid is great for new applications that require high-speed Ethernet.  The solid cables can transmit and receive across long distances and have a higher data rate compared to stranded.  The downside is that solid cables can break, and do not bend or flex well. Stranded is a better cable if you have to bend, twist, or flex the cable. It’s also better if you have to run short distances.  Stranded is made up of smaller gauge wires stranded together which allows the cable to be flexible and helps protect the cable. They move with the machine and will not break as easily as solid cables.

EthetNetCables_755x220To recap, remember the four short bullet points below when choosing your next cable:

  • Ethernet – transmits data
  • Ethernet/IP – transmits data to many machines/devices
  • Solid – good for long distance and little flexing
  • Stranded– good for short distance and flexing

To learn more visit www.balluff.us

Heading to Fabtech? Read this first.

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:

  1.   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.

Continue reading “Heading to Fabtech? Read this first.”

Broken sensors that won’t stay fixed!

It’s another day at the plant, and the “Underside Clamp Retracted” sensor on Station 29, Op 30 is acting up again.  Seems to be intermittently functioning…the operator says that the line is stopping due to “Error: Underside Clamp Not Retracted”.

You think to yourself, “Didn’t we just replace that prox last week?”  A quick check of the maintenance log confirms it: that prox was indeed replaced last week.  In fact, that particular prox has been replaced seven times in the last six months.  Hmm….the frequency of replacement looks like it’s going up…four of the seven replacements were performed in the last two months.

What’s going on here?  Is it really possible that seven defective proxes just all happened to end up at Station 29, Op 30, Underside Clamp Retract?  Not likely!

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Implement Hassle Free Tool Changes

The Problem

From conversations with many of our customers, I have found that there are two key problems encountered when working with tool change-outs:

  1. Tool Identification:  “How do I know I have the right tool in there for the right job at the right time?”
  2. Cables & Connectors:  “How do I remember every time to disconnect them before the tooling is removed?  We spend thousands each year repairing dies with the cordsets torn out.”

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How to Maintain Your Rotating Connection


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In the design of automation equipment everyone is looking for an edge.  How can I make parts faster or easier or safer?  I’m sure you don’t encounter the need for 360 degree rotation everyday; but when you do, it can become a pain to maintain sensor and actuator information or even a network connection.

There are two different ways to maintain your connection in a rotation application:

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