Motors, R&D and Politics

Steve Meyer
February 23rd, 2008.

The “Green Revolution” is under way. Regardless of how you rationalize it, there is a lot of activity around reducing the amount of energy being consumed in almost every aspect of American life. For the most part, its well intentioned. As good stewards of the resources we have, we should use them responsibly.

Energy conservation has been an active part of the mechatronics world for some time. The variable frequency drive, now  a $1B+/year product is marketed and sold because of its ability to reduce electrical consumption in about 1/3 of all applications. So we who are part of the drives and controls community have been in the vanguard of energy conservation for many years. An often overlooked fact. We’ve been “Green” for decades.

Some years ago, the Department of Energy spent hundreds of millions of dollars attempting to increase the energy efficiency of the electric motor. They tried to stimulate fundamental R&D with research into high performance lamination steels and superconducting wire. Remember superconducting? Going to change the world. Someday. That day hasn’t come. Motors with superior lamination materials are available but at a cost premium. So we didn’t get a big energy return on our DOE investment. And the incremental increase that high grade laminations provide isn’t enough to justify the expense for the most part. Otherwise, ALL motors would have exotic laminations.
State governments are poised to mandate that manufacturers use some proportion of high efficiency motors to get reductions in power consumption. Instead of building more powerplants or using nuclear mini-reactors to make more power available. Hey, let’s pile on more regulations and costs to our manufacturing sector and see if they survive. Bad idea.

Let’s pass a law that electric motor manufacturers make more efficient motors and let them figure it out. Another Bad Idea. Electric motors are extremely efficient already. Most motors run 80-90% efficient. That’s why electric cars are a great idea. In that situation its not the motors that are the problem, its the battery. But that’s another story.

You can’t just pass a law and get more efficiency. There are physical limits. Politicians generally don’t have technical backgrounds, and by getting involved in the R&D process they can make a real mess.

The American public pays more than $7Bil a year for the DOE to do whatever it does, and from the projects I am aware of, the benefit we get from those expenditures is minimal. We need to get some people from our industry involved in the DOE process who can inject some informed common sense into the situation. The solutions are available, they are just not making it through the bureacracy.

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Time and Technology March On

Steve Meyer
February 20th, 2008.

Motion Control used to be its own unique domain in the control world. People tended to leave you alone. Few understood it. And because there were so many problems, many avoided it. Don’t get hooked up with to it.

So control most of the major technologies grew up on their own. CNC’s first developed in the 1950’s were definitely their own thing. Very complex math engines that were used to manage metal cutting operations to make complex strucutres. Modern aircraft would be pretty much impossible without the incredible precision available through CNC’s.

Process Computers were full mainframe computers with totally unique hardware for operating chemical refineries. Wire trays with miles and miles of wire running through process plants with ever increasing demands for information.

PLC’s are relatively recent control platforms that gained great popularity since my introduction to them in the 1980’s. And they have migrated dramatically since then. Equipment that used to fill relay racks, like their process control cousins, is now available in a lunch box style rack.

And variable frequency drives, also a relatively recent technology, have seen cost and size improvements that are astounding. Today’s 1HP drive is available from Asia at $100 selling price and they are small enough to fit in the palm of your hand.

Enter the personal computer. Once the domain of early information systems programmers, now are the platform for the control systems they once monitor data from. The top CNC’s of today are shipping on PC processors.

Process control on PLC? Never! Really? Honeywell migrated its process controller platform to the Rockwell Logix platform a few years ago. Motion Control on a PLC 20 years ago would have been unheard of. Now, everyone claims to be able to do motion in the PLC.

So where is all this going? Processor technology is getting cheaper. Any application will be fair game for a less expensive processor with much greater capability. Soft motion? Soft PLC? Sure!

What we need to consider is the value that control industry products bring. Not the hardware specs, but what the product does for the customer. The customer’s value.

That’s what industry professionals bring to the relationship, seeking the customer’s best value. That’s how we win, now and in the future.

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My first brush with Mechatronics came courtesy of White Sands Missile Range

Larry Boulden
February 19th, 2008.

Imagine a missile launch,” my boss explained.  “It comes out of the silo without warning, goes like a streak, and sometimes explodes on launch.  We want an unmanned tracking mount that will sit close to the launch area, pick up the missile, and track it  — no matter what.”

The engineering assignment was pure Mechatronics.  Make the mechanical pieces strong but light enough for the accelerations and slew rates to come.  Give the drives enough power, speed, and responsiveness. Make sure the sensors could pick up the bird, lock on it and follow it to the death.  Fashion controls that would tie it all together and make it all work.

It was, in short, classic Mechatronics, though we never used that word.  It would be two years later, in 1969, before Tetsuro Mori, a senior engineer at Yaskawa, coined it.  But how the practice of Mechatronics, and the engineering disciplines it uses, have grown in the years since then.

According to Wikipedia, Mechatronics is the synergistic combination of mechanical, electronic, and software engineering.  The purpose of this interdisciplinary engineering field is the study of automated machines from an engineering perspective.

The “automated machines” so created range from planetary rovers to production machines, from automotive subsystems like antilock braking to synergy drives.  And yes, the roster of Mechatronics successes includes a bevy of common consumer products such as autofocus cameras, CD-players, washing machines, and hard drives for computers.

A measure of its acceptance can be inferred from the number of efforts to broaden the definition.  Leading firms like National Instruments would like to see emphasis on testing as a key part of Mechatronics.  Dr. Sugato Deb of NI notes that the common definition of Mechatronics does not include testing, and concludes, “Perhaps it should.”

Another area of interest is in linking hydraulic and pneumatic components into Mechatronics systems.  Paolo Catterina of EUROelectronics has been using NI controls in designing a high-speed press based on a hydraulic cylinder.  EUROelectronics is a machine builder that was asked to design a closed-loop hydraulic-cylinder control system for a die-casting press machine. At a recent Mechatronics event, Catterina explained. “The high-speed press moves anywhere from 0 to 10 m/s and therefore requires a high-speed control system. Position and pressure control of a hydraulic cylinder is a common application in the industrial automation field, but the precision control of such systems has traditionally presented significant challenges because of their high speeds and pressures.”

Here at Design World, we regard Mechatronics as one of the most challenging and exciting subjects we cover.   We hope you’ll visit our Project Mechatronics Website, www.projectmechatronics.com, and check out our blog, our Wiki, and the rest of the coverage we offer.  While you’re there, we suggest you log on and add your comments to the Wiki.  We welcome your contributions to Project Mechatronics.

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Mechatronics’ Present and Future

Richard Comerford
February 01st, 2008.

Having just gotten back from the annual extravaganza known as the Consumer Electronics Show, I’m happy to report that the outlook for mechatronics is definitely positive. The integration of electronics and mechanical systems was clearly in evidence at CES, on both the micro and macro level.

To start small, one of the more impressive in-suite demos was presented by Microvision of Redmond, WA. The company has developed what it calls the PicoP engine for projecting video and images onto any reflective surface. The engine consists of a MEMS chip with a mirror that can steer RGB laser light to raster the image onto the surface. An entire system was contained in a case about the size of an iPod. There were also a lot of new game controllers that rely upon the ability to sense motion to provide an extra dimension to gaming, as well as hepatic feed back systems to let you feel the pain.

At the other end of the size spectrum, there were the huge MEMS micromirror projection systems in the Texas Instruments booth. There were also several concept cars from Ford demonstrating the use of electronic systems for control of steering, abs, air-bags, and other critical systems that were once strictly mechanical. This list could continue to grow, but it’s clear that the marriage of electronics and mechanics is still on very solid footing.

I also saw a number of display systems, and while they didn’t rely on mechanics in the larger sense, it was their physical performance that started me thinking about the future of mechatronics. What I was hearing is that this one type of display system, while its appearance was excellent, was having problems related to material stability over time. It was critical to the products success, yet it was something that was only found out once many, many units were in production.

Today we are at a stage where we can simulate the interaction of mechanical and electronic systems with a good degree of accuracy. But when it comes to the performance of materials over time, or in a particular design for that matter, we seem to still be in the dark ages. The materials/chemical engineer can use his or her expertise to suggest what is likely to happen, and has tools for creating new molecular compounds, but I know of no system today that will allow you to integrate that knowledge into the realm of electromechanical design.

Once we’ve tackled the problems that mechatronics poses to unifying electromechanical design, I hope we’ll be able to take the next step into materials science and bring in the ability to alter or design new materials that will fulfill the end requirements of product in new and unique ways. But I guess we have to learn to walk before we can run (and after having been all over the huge Las Vegas Convention Center for CES, I’m happy for now to still be able to walk).

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Mechatronics Training

Steve Meyer
January 31st, 2008.

If mechatronics wasn’t difficult enough to define (concisely), try and get a degree in it!  Interestingly, with the increased attention that mechatronics is receiving around the globe there are established degree programs in Europe and Australia.  Some schools in the US are picking up on the trend.  The electric car races, Darpa Challenge and battling robot competitions, with some very hefty cash prizes, have stimulated interest from thousands of participants and spectators alike.

The latest innovation is the partnering of schools, automation equipment suppliers and funding from the Department of Labor.  DOL (Department of Labor) estimates that 10 million technical factory jobs could go unfilled by the year 2020 without an aggressive effort to train students and teachers.  The assessment of American labor’s capability to deal with emerging technology trends on the factory floor has lead DOL to contribute millions of dollars in cooperation with schools and equipment companies to make state-of-the-art training available on a large scale.

Festo Corporation is partnering with community colleges and universities around the US to provide sophisticated training simulation equipment in pneumatics and control, hydraulics, programmable controls, sensors and electric actuators.  These systems are designed to provide students with real-world experience in robotics and complex material handling applications that will impart the kinds of skills needed in the emerging technical markets.

These trends lead to increased American competitiveness in world markets.  Let’s hope it continues.

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Actuators

Steve Meyer
January 30th, 2008.

Another area of Mechatronics that is very confusing is the area of actuators. The problem is that you can buy actuators that are assemblies of several components, or you can buy the components, and they’re all called actuators. This is traditionally an ambiguous area of mechatronics and I will try to add a little definition to help clarify things a bit.

An actuator assembly is made up of 5 different technologies integrated into a package. These 5 are;

• motive power source
• means of transmission
• bearing or guidance
• frame or support structure
• position feedback (in most cases)

So an actuator assembly can have many components. Each one needs to be understood in terms of its contribution to the overall result. But with actuator assemblies, the integration engineering has been done by the supplier so that you don’t have to. Most of the time this is the most cost effective and convenient way to deal with the requirement of a specific application.

But many times the pre-engineered solution involves some compromises. That’s totally fair since the solution offered by a supplier must be suitable to a number of different requirements. If an off the shelf solution fits, or you can make it fit, then you’re “good to go”.

But if you are having trouble finding an “off-the-shelf” solution, navigating the technology solutions that exist can be a daunting task. Actuator technology is an excellent example of the intersection of many diverse technologies that is characteristic and challenging in mechatronics.

Motive Power can be electric motors, air and hydraulic motors or air and hydraulic cylinders.

The Means of Transmission in the motor cases will require a mechanical rotary to linear conversion, either belt and pulley, leadscrew and nut, or rack and pinion. Cylinder actuators do not require the conversion, but cannot take mechanical advantage as the rotary systems do, so as the force needed increases the size of the cylinder increases with it.

Bearings are a big topic on their own, but in the actuator linear bearings are usually ground rod with ball cages or square cross roller types.

The frame or support structure is whatever is needed to mount the parts together. Leadscrew systems are fairly simple as they pose no particular stress components, just passive weight loading. Belts and pulleys must be tensioned and the support system must be able to handle the tensioning load without deflection.

Feedback requirements are another broad topic because the feedback device must interface to a controller. Typically the focus of feedback is accuracy but sometimes too much accuracy can cause problems. The other major consideration is the operating environment. High temperature or harsh atmospheres will restrict what technology solutions are appropriate.

More to come on each of these topics.

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Common Terms are Not So Common

Steve Meyer
January 22nd, 2008.

I have worked around electric motors for a long time. It still blows my mind that we can’t seem to settle on common terms and definitions of things we work with on a daily basis. When is a motor AC Synchronous or DC Brushless? They are identical. Same motor.

So you have to start from the beginning of the motor family tree and work your way through it. What makes a motor AC versus DC. The only definition I know of that makes any sense is this;

An AC motor has only one magnetic field, in the stator, and induces a second magnetic field through induction, into the rotor. The rotor becomes magnetized and follows the circulating magnetic field in the stator by passive attraction. This is why most AC motors are referred to as induction motors, because the magnetic polarity in the rotor is induces. AC motors as a result are constant speed machine based on the frequency of the electrical excitation. Since that’s mostly 60 hertz in the USA, its usually some multiple of 60, most commonly 1800 RPM (minus some rotor slip). AC machines require an inverter to change AC into DC and then DC into variable frequency AC in order to achieve variable speed performance. Due to decreasing costs for the AC motor and recent cost breakthroughs in inverter technology, AC variable speed is the dominant solution.

The DC motor has two active magnetic fields, one of which may be permanent magnet and operates by repulsion and attraction at the polarity of one of the magnetic fields is reversed. Reversing polarity in DC machines is often done mechanically using brushes, but there are many branches of the DC motor family such as Stepping Motors which do not use brushes.

DC motors are intrinsically variable speed and have other characteristics that make them a viable choice in many situations. The cost of permanent magnets has made them more expensive in larger designs. So DC machines are in somewhat declining popularity.

So it becomes possible to create lots of special purpose motors to solve different problems. And as the industry has evolved, navigating the many technology choices has become very difficult.

We have standardized on a 3 phase brushless DC motor for servo systems. We could have any number of phases, but it seems that 3 is very popular, probably as a result of the many 3 phase AC winding machines available. So from an electrical power standpoint, the motor is 3 phase. And the magnetic field in the stator is circulating.

But the rotor is permanent magnet. There are some 3 phase AC motors with buried magnets to increase the flux of the rotor. They are called “salient pole” because of the enhanced magnetic strength of the rotor. And because the rotor follows the stator’s magnetic orientation without slipping, its called AC Synchronous.

So which is it going to be? AC Synchronous or DC Brushless. Call me “Old School”, but I think its DC Brushless every time. Anyone out there agree?

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Energy and Control

Steve Meyer
January 12th, 2008.

Looks like I was mistaken about one thing recently, and its probably not the only thing.  The new clothes washer we got to replace our failing machine does not use a switched reluctance drive.  Its an intelligent inverter drive with a standard AC motor.

As somewhat of a technology freak, this comes as quite a surprise.  I had been involved in a lot of advanced motor R&D during the late 1990’s.  Switched reluctance was touted as the next big thing in motor technology.  In truth, its a permanent magnet machine that uses high energy magnets (neodymium iron boron), which are expensive.  So in the effort to advance technology, we never escape the cost impact.

Where cost is not constrained, anything is possible.  Men on the moon, robots on Mars, telescopes in space that see the edge of the universe.  Superconducting electromagnets that contain the power the of sun, particle accelerators that approach the speed of light.  Almost anything you can think of.

But in normal everyday events, everything is cost constrained. So when customers and engineers ask if something is possible, there is always the follow on question, “How much is it going to cost?” We need to remember to answer that question explicitly, even if its not asked.

As it turns out in the washing machine, it is a lot cheaper to change the mechanical transmission into a simple belt and pulley system. By using a large reduction ratio to give the small ac motor the needed mechanical advantage and adding an intelligent inverter to the standard ac motor the new drive train is transmissionless and lower cost. This new system even includes extra sensors to detect proper motion from the tub (I think its an inductive proximity device tied to a counter on the controller that tells how fast the tub is moving). This machine cost a lot less than its predecessor, runs a lot quieter, and uses less energy over a year’s time.

Yes, the cost of the final solution is lower, and the overall machine performance is better. But the lesson that is most significant from this example is; the biggest improvements in energy reduction are not the result of trying to squeeze the last percentage point of efficiency from the motor. The biggest reduction in energy cost comes from a better mechatronic solution, leveraging the mechanical, electrical and control system together and getting the best overall result.

Coincidentally, this is also the best return on investment for the manufacturer and strengthens GE’s position as an appliance maker and employer.  But the same benefits are available to everyone in manufacturing.

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Motor Industry and the New Year

Steve Meyer
January 03rd, 2008.

Hope everyone had a great holiday and a successful year in 2007.

I was reviewing the Department of Commerce figures for electric motors. Hey, its just something I do.

A few years ago when I was hired to help a young high tech motor company in Denver understand the marketplace, we started with the Department of Commerce data for electric motors and generators. We studied the data and went into an interesting exercise in analyzing the market. At that time the US produced approximately $12B in electric motors. That includes all the industrial and high tech stuff, as well as starter motors on cars, alternators, generators and fractional horsepower fans you find around the house. Big numbers, lots of parts.

I recently had occasion to get the latest census data for the year ending 2006. The same market segments, but the US only made about $7B in electric motors. Not a good thing for America. Less jobs, less steel, copper, insulation, motor housings.

We still buy a lot of products that use electric motors, so we must be getting them from other countries. And if the electric motor is the #1 energy consuming device in the United States, we had better be looking at where and how well those motors are made. How efficient are they, how long will they last, who makes the profit on selling them here.

The business side of the problem gets to be two-fold; do the multi-national companies that were created by the American enterprise system have any responsibilities to the country they originated in? and are there any companies out there with technology and processes that will permit new motor companies to emerge? I say yes to both.

Let’s make 2008 a great year for the electric motor industry.

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Thoughts on the Coming End of Year

Steve Meyer
December 17th, 2007.

End of year is coming. I’m sure you’ve noticed. Christmas shopping is in full swing. I enjoy the end of year pause. Its a great time to reflect. Sometimes a great opportunity to reflect on the big issues of life that take a back seat during the rush of the urgent daily events that occupy our time.

End of year in the business world has its own peculiarities. I’ve gotten a couple of notices from motion control equipment vendors. Spend your budget before the year ends. Special pricing available.

The rationale is to spend the funds you have been allocated so that you don’t get shorted in next year’s budget cycle. Use it or lose it. This may not be the best logic for purchasing something, but it is sometimes a reality in our business processes.

I have been a part of this process in the sales division of a couple of large companies. A directive comes out that we need to pull in every order we can in December to make the sales revenue for the year as large as possible.

But the one-year business planning and evaluation process leaves something to be desired. Frequently driven by stockholder perception about our business, management is compelled to achieve performance. Is this reality, or someone’s wish of what reality should be? Are financial analysts running the business, or are the stakeholders running it?

How do we integrate long term strategic objectives in an environment where monthly sales goals are all that matters? How do we insure adequate investment in new product development so that sales revenue can grow? How do we insure timely product development cycles when revenue growth is at stake?

Let’s take some time this end of year and think about new ways to run things, let’s figure out different ways to plan for, and measure success. And let’s take time to reflect on all our blessings.

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