In the wind energy arena the biggest change has been the shift to direct drive permanent magnet generators.  By eliminating the gear “increaser” to convert the low RPM of the propeller system to a high RPM for a standard high power generator.  This is crucial step in bringing the cost of wind power down. Current systems are weighing in at 100 tons and have to be suspended above water or land 165 feet in order to pick up sufficient wind currents to be economically practical.

There is no single solution that is ideal for wind applications.  One supplier has a generator that is made up of 4 smaller units on a single large ring gear.  This system seems to have significant advantages in reducing the size and weight of the generator and makes maintenance more simple in the event of a failure.

Among the major mechatronic challenges driving change in the motor industry, electric vehicle applications are continually pushing the boundary for energy density and efficiency.  The performance demands of electric vehicles and other mobility applications make every percentage point of efficiency crucial to the range of the target vehicle.  This has led to a rash of new motor and drivetrain designs with a variety performance capabilities.

Each new innovation seeks to organize the basic materials of the electric motor in a new way to improve some aspect of performance.  Electric motors are copper conductors, “soft” magnetic steels and many times, permanent magnets.  The basic costs for copper wire at $5-6 a pound, commodity strip steel is about $.50 per pound but has to be punched in precise shapes, coated with insulation and stacked into larger assemblies, and $16. per pound for permanent magnets.  Complex processes associated with motor manufacturing make motor costs considerable.

In a recent development teams in academia in Australia and the US have developed simple low RPM motor structures based on polymer actuators referred to as “artificial muscle”.  While this development is in its early phases, the simplicity and low cost are significant and very appealing.  A demonstration of the new technology can be seen on YouTube at;  www.youtube.com/watch?v=ZcCPNJR5PCMand it is very much worth the watch.

The only sure thing is that we continue to meet the challenge of new market needs with innovation.

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Many of the constraints of the work are environmental.  If work is being done outdoors, then temperature and humidity are a factor.  Felling trees and in the forest requires extremely high forces due to the work needed to cut through a tree and drag it to a truck to be hauled off for processing.  Processing trees, even in a plant environment, requires some serious hardware, 125 horsepower band saws are not unusual.

Doing work on a ship or oil rig has additional constraints because of the presence of explosive fumes and fuels.  Often the need to avoid any possibility of igniting a combustible atmosphere causes engineers to apply pneumatic control systems.  Yes, there is still a compressor somewhere to generate the compressed air supply, but that is usually remote or contained to avoid exposure to the volatile atmosphere.

Environmental constraints come in many forms.  Extremely high temperatures push the limits of what is possible.  Making glass, semiconductors, and primary metal processing are all high temperature environments where engineers have developed whole technologies in order to bring us the materials we use in everyday life.

The simplest action of rolling or sliding becomes a real challenge when environmental constraints are added to the work statement.  Sawdust becomes a potential abrasive in woodworking environments that can introduce severe wear in moving parts.  Corrosive and explosion proof atmospheres as well as food industry applications introduce all sorts of chemical compatibility problems that require special materials and processes in order to meet strict guidelines for safety.

As always, resourceful engineers have worked out solutions for all of these difficult applications.  One family of solutions to rolling applications is the use of all ceramic bearings.  No steel, no lubrication.  None is needed because the ceramics are extremely high purity to start with and have extremely high precision surfaces eliminating the need for lubrication.  No outgassing or contamination to worry about.

Other solutions take the form of air bearings and non-contact material handling devices.  Air bearings have become more readily available for conventional applications, but are particularly compelling in large machinery applications where precision is required.  Large flat screen display glass  presents unique challenges that successfully addressed using a combination of air bearing regions and vacuum regions to move the glass without actual contact and with overall flatness measured in millionths of an inch.

A unique solution in pneumatic material handling takes compressed air driven into a funnel shaped recess and creates a vacuum in the center and an air cushion at the edges where the air is exiting.  This creates a vacuum pickup that never quite comes in contact with the part, leaving no marks.  Perfect for solar cell and some food and beverage applications.

Engineers continue to meet the unique challenges of industry and create commerce at the same time.  And that’s what it should be about.

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Getting it done on time and in budget are basic requirements of the challenge.  Over the years the only thing I have learned is that things always take more time and cost more than what was planned.    Good planning rarely eliminates mistakes or discovering an unforeseen problem late in the project that can jeopardize the whole effort.

The fix, if there is one, is building some slack in the project work plan.  So if it is at all possible, plan for 10 percent of the time and money to be set aside for contingency.  This will allow room for corrections to take place within the project plan and help prevent delays to the project deliverables.

Among many competing priorities in machine development, one that is rarely discussed is life expectancy.  Machine life expectancy is more subjective because component selections are not simple and straightforward.  Many decisions will be based on judgement and experience rather than on an explicit technical basis.

Something simple like a pulley may be perceived to be more durable if made of steel instead of aluminum.  But that component decision will increase the load mass.  The increased load will then require a larger motor and drive to power it.  And there are hundreds of similar choices that have to be made just like this.

Sprocket and chain mechanisms are generally indicated when high loads are being powered.  But in a situation where high life expectancy or reliability are involved, may be preferred over belts and pulleys.

Mechanical components of this type are subject to significant variations in cost versus life expectancy. The basic metallurgy of parts will impacted.  In one project, the balancing of load versus durability lead to the use of titanium.  The increased cost of the material was offset by reduced cost in the motor and drive solution.

Plating and coating of parts can be a significant opportunity for improved life.  Nickel plating has excellent performance in low friction, corrosion resistant coatings.  There are a number of hard Teflon coatings that can be used for reducing friction.

The life expectancy question is also connected to the maintenance cost of equipment.  For new machine designs, the maintenance issues are largely unknown and are part of the learning curve.  But the reliability of any piece of equipment is a huge issue.  And a lot harder to engineer in a systematic way.  But always worth the effort.

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One strategy involves speed, torque and time.  These three variables are a connected system that is defined as the mechanical work to be performed.  Speed torque and time must be optimized according to the priority of each variable.  The difficulty is in exploring three variables simultaneously.

Two variable tradeoffs are no problem.   So having a two variable strategy for three variable systems would be really handy.  And as it turns out you can consider any one variable as a constant for the purpose of optimization.  So its easy enough to consider time as constant and optimize torque and speed.

This strategy turns out to work really well.  The speed and torque requirement for a given actuator system was very well defined and had been prototyped with good performance.  But the customer needed to optimize the cost of the design.

The cost of servo systems primarily follows the power requirement.  The more torque needed, the more expensive the servo system.  So the first place to work on cost optimization is the motor drive combination.  If the torque requirement can be reduced, the cost goes down.

So how do we reduce torque? You can either trade off time, or look for ways to reduce the load inertia. If time is a priority, then reducing the load inertia is the way to go.  And reducing the load is most easily dealt with by material substitution.  Steel is pretty strong, but may not be needed.  Aluminum may be a suitable substitute at one third the density of steel but half the strength.  Strength is absolutely required and reducing the weight is going to generate big cost benefits, titanium may turn out to be the best choice.  I have had applications where titanium was the used, and it was the right choice.

Sometimes the materials substitutions can be significant.  It is possible to use plastics like polycarbonate as an alternate to aluminum.  Again, the material strength is lower, but polycarbonate is so light, that more material can be used volumetrically to achieve the necessary strength, and still end up reducing the weight of the load.  So this is a viable option.

In the project I am currently working on, we have reduced the weight of the actuator system by about 25%.   What was really amazing, and unexpected, was that the weight reduction and rearrangement of the load structure resulted in a 56% reduction in the torque required.  The motor and drive has been reduced from a Nema 34 motor to a Nema 23 motor.   And further improvements are expected.

Which is why I like my job.

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Pretty weird.  From a couple of different perspectives.

First of all, the original discovery of Neodymium Iron Boron as a high performance magnet material was paid for by the US military in 1982.   General Motors developed a process that took liquid metal at high temperature, rapidly cooling the material in a spray cast process that resulted in a high quality magnetic material.   So this should go in the history books as another breakthrough of American technology.

The original goal was to find a replacement for Samarium Cobalt which has always been a tricky material to deal with due to the wild fluctuations in the cost of Cobalt.  The other implication here is the fact that the US military felt it was important to maintain stable supply of permanent magnets for missile guidance.  So that makes the sale of Magnaquench to Archibald Cox, who then sold it to the Chinese, a very peculiar thing.  If there was a strategic military interest in permanent magnets, it was not part of the consideration when we lost Magnaquench.

While GM was planning on reduced size and weight for its engine starters as the benefit of neodymium, the entire servomotor industry is standardized on neodymium magnets for its motors.  At almost $1Bil a year in servomotors sold in the US each year, this is a pretty big deal.

The financial markets have been having a heyday with the situation.  Speculation is rife that the Chinese government will continue to tighten supply of Neodymium magnets to the rest of the world. So in addition to the natural effect that pricing will rise due to short supply, speculators will drive prices even higher in the next couple of years as the situation worsens.

And the reason Neodymium magnets are in such demand is that they make great electric motors for industrial automation and for powering electric cars.  So as the electric and hybrid electric manufacturing comes on line, tons of new supply will be needed.  The current plan for wind power also requires large amounts of permanent magnets.  So a lot of the “Green Revolution” will depend on the availability of these materials.

Having attended a couple of industry conferences on magnetics, I have become plugged in to the current state of the industry.  There are huge deposits of ore in the US and Australia.  Actually, neodymium is not particularly rare, which means it isn’t terribly expensive.  But dysprosium, which is needed to stabilize the neodymium magnet against high temperature demagnetization, is quite a bit more rare and makes the permanent magnet a lot more expensive.

The rare earth elements all occur together in the ores, and when the mines are developed, they are graded carefully for the yield per ton of about a dozen different rare earth elements.  So the really important fact is that the two largest rare earth mines in the world, in California and in Australia, will be extremely important in restoring the balance of supply in the near future.

And, in fact, the California mine is already well on its way to supplying the US’s needs.  Because people in the industry, and American and international investors, were smart enough to see the future coming.

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One variation on 3D printing uses chopped glass fiber and ABS plastic that can be melted and flow the way conventional 3D printing materials behave.  The combination of glass fibers with ABS results in much harder parts and this increase in part strength is just right for many applications.

A straightforward adaptation is to make 3D plastic parts from and cast the part in plaster or a ceramic that can be used as a mold for conventional metal casting techniques.  For many parts, a lot of detail can be captured easily and high quality parts can be produced cost effectively.  If the parts are small, you can print many of them so that they can be connected in a “family” mold.  Again, this is a very well established metal forming technique that is made more cost effective with 3D printing.

Higher strength is possible with a wide range of 3D metal processes.  In one process, metal powder is fused in tiny regions using a focused laser.  As a layer is completed, a screed pushes a fresh layer of powdered metal and the process repeats.  Solid metal parts without machining.

Another method uses metal powder that is combined with water and lubricants and binders so that the powdered metal can be fed through a syringe.  The resulting slurry can be formed into parts using low end printers.  The parts are cured to drive out water and then the parts are ready for sintering.  The resulting parts have 80-90% of the strength of the native material.  All kinds of materials are being experimented with like bronze, steel and stainless steel.

There are even exotic alloys like Titanium that can be formed using 3D printing techniques.  Shapes that are impossible with machining techniques are possible with 3D printing.  And the process also makes possible combinations of alloys that are not possible with other processes.

This leads to a lot of questions about the future of manufacturing.  Will this technology mature to the point where it will displace machining of bulk parts like engine blocks and pistons?  Does 3D printing offer lowering costs for mature manufactured parts?

These are just a few of the possibilities that may be on the horizon.  When it comes to complex parts like plates for fuel cells, the 3D printer may be the breakthrough that is needed to achieve cost performance that make a lot of new technology cost effective.

Does 3D printing represent a lowering of the cost of entry in production parts.  This aspect opens even more questions.  In markets where the tool up to manufacturing something like a car is so high, the 3D printer may create an order of magnitude reduction in those costs.  The cost of new product development can be substantial, so any new technology that lowers development cost is likely to bring a whole of new ideas to the party.

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Linux attracted thousands of participants developing code for all sorts of applications simply because there were opportunities to improve poorly performing applications and make the computing more successful.  There was even a development group making a Linux based software programmable controller.  What a concept!

Not only was Linux a huge success in transforming complex and fragile operating systems, the most innovative aspect was the idea of development communities.  An idealistic approach to the cost of developing complex applications.  Commercialization and profitability took a back seat to solving important problems.

The “freeware” community has made its way into the motion world.  The Arduino development community has created a new processor and code platform that has among its many freeware applications, stepping motor drive circuits.  

There are an emerging number of part making systems such as 3D printers and low cost 3 axis machining systems that make prototype parts directly from solid model programs.  Machining systems are sometimes referred to as subtractive processes, so I suppose that extruding or jet printing wax would be additive processing.  Anyway, part fabrication has really taken off.

Surprisingly, even the part makers are creating their own development community.  Check out makerbot and fabathome on the web.  The effort is focused on developing part fabrication technology that is inexpensive, almost free.  Free plans, kits, parts, drivers, low cost motor drive circuits, everything you need to start making stuff.  Some amazing solutions.

Which raises a really interesting question; Is this the future of manufacturing?  How many new products could be produced using low cost tools?  What kinds of production capacities can be reached with this approach?

Interesting area to speculate on.  If a desktop part maker can be made for less than $1500, how many parts can be made without major problems with the machinery?  This suggests some really interesting possibilities.

Additive part fabrication can take a while, so part throughput is very slow.  So what? If it takes 15 minutes to generate a part, get 10 of them.  Then your down to a part every 1.5 minutes.  At $15,000 how many parts could be generated in a year?  4 parts an hour in a 2000 hour year would be 8000 parts amortized at .19 cents per part.  That means you can throw the part printer out after a year. Wow, that’s a deal.   So if the part makers can hold up for a year, you can throw them out and get new production equipment at the .19 amortization rate.

Seems to me that mechatronic innovation is solving some tough manufacturing problems at levels that may ultimately change how we do manufacturing.

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The logical extension of 3D solid modeling software is 3D rapid prototyping.  This technology has also gone through significant changes over the last twenty years to reduce the cost and make it available to a wide audience.  Development of file format conventions have made the link between 3D solid modeling and 3D printing very straightforward.

In its early days, 3D printing started out as stereolithography.   This term was coined for the two laser beams that were used to cure liquid polymer in a large tank.  Precision steering and focusing of laser beams has been around for a while from the laser printer world.  Adapting the laser printer technology resulted in tremendous precision with part accuracy of .001″ in any dimension being easily achieved.  This made evaluating complex fit and function very easy for manufacturers.  At its inception, stereolithograyphy machines were $250,000.  The high price tag made stereolithography the domain of Fortune 500 companies. But for high volume, complex parts like intake manifolds for automotive engines, stereolithography was, and still is, a great way to save money when a new part design is required.

Heat curing a liquid polymer gave way to heating a low melt point polymer to a liquid and dispensing it in small beads as a lower cost solution for making complex shapes.  To the point where there are a wide variety of solid model printers in a desktop package that are priced under $20,000 with really sophisticated features like multicolor part generation, and new low end machines coming in from China at $1500.

Experimentation with different chemistries has created a wide range of options with regard to material strength and imparting unique properties to the parts.  One variation is ABS plastic that is available with glass fill.  This produces much higher strength parts than the polymers.  Another whole branch of 3D printing is dedicated to making metal parts that are too complex or expensive for conventional machining.  Amazingly, the 3D-based solutions are resulting in much lower costs.

The implications are transformational for new product  development.  First, the combination of 3D solid model software and 3D printing technology taken together represent an order of magnitude reduction in the cost of developing new products.  The technology make more information available leading to, hopefully, better design.  This also means that the amortization cost of the development activity is also greatly reduced.  Leading to better goods at lower prices.

The second transformation is that lower development costs mean that the technology can be applied to lower price products.  Previously, these technologies were only cost effective in automotive and medical instrument design applications.  Now, the potential exists to dramatically improve products at lower price and volume levels.  Sneakers, for example, have been impacted by this technology leading to a wide range of new products incorporating a variety of new ideas.

And the transformation is just beginning.  And all of it mechatronics driven.

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Similarly, in recent years, there have been a number of significant breakthroughs that offer great potential for the improvement of many current technologies.  But more subtle transformations are taking place throughout the industrial landscape that offer new opportunities yet to be explored.

In many areas of part production, there are solutions that offer reduced cost per part.  The emergence of new CNC’s that are available at the $10,000 level reduces the amortized cost for producing parts by as much as 500%.  Simply put, it you have to produce 1000 parts on a machine tool, the final cost of the part is significantly impacted by the cost of the machine tool.  A $50,000 machine tool will cost $50 per part across 1000 parts.  A $10,000 machine tool will only cost $10 per part.

This economic shift may make it possible to enter a market with an improved price point for an existing product, or create an opportunity to do something new that wasn’t possible because of cost and volume constraints.

In similar fashion the metals industry has consistently worked to developed processes and technology that allow part cost reductions, and more recently, smaller batch sizes for certain applications.  The smaller batch size has the same effect on cost, it lowers the investment cost for improving old designs or coming up with new ones.

The same trend is in place in the controls arena.  Processor technology that used to cost $20. a few years ago is available now for $2-3 and network versions that permit Internet interface are available for around $5.  This makes it practical to embed intelligence and communications in products even if the application is relatively simple.  The low cost is a compelling value in many products.  And in many arenas there are libraries of application code that already exists that may provide 60% or more of the development code for something you are working on.

Energy is still a bit of a limitation.  We don’t have a “Mr. Fusion” nuclear reactor that runs of kitchen scraps.  But things are looking up in this area with lithium based batteries making great strides in energy density.  And there is substantial improvement on the way.

But the real point here is;  Dust if off and Try it Again.  Take those “back of the napkin” sketches you’ve been tinkering with or thinking about and look at them again from the perspective that there dozens of technology improvements out there that will reduce the cost of the product you were thinking about a couple of years ago.  The change in the economics, as amortized cost, or the cost threshold to get your first batch of parts made, are factors that have a huge impact on the feasibility.

It just may be the time for a breakthrough.  A second industrial revolution.

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In addition, the Magnetics 2010 Conference will be running concurrently at the same venue.  Magnets are a strategic material without which many motors would simply not operate.  In the ever-changing motor industry, there is always a new design that seeks to make an enhancement over previous solutions, or introduce a new solution to old problems.  Declining prices for Neodymium Iron Boron magnets over the last few years have created a number of novel design shifts which have been instrumental in bringing more varieties of permanent magnet machines into the forefront of motion control and mechatronic technology.  To the point where over the last two years a resurgance of permanent magnet rotor designs have been created to improve the energy denisty and lower the cost of specialty motors in washing machines and air conditioning compressors.

This last development, combined with the forecast increase of hybrid electric car sales coming this year, are expected to increase the sale of permanent magnets by 10-15 percent by 2011.  That’s a staggering jump in a market that is almost exclusively supplied by China.  And there is no assurance that China can meet the forecast production.

The US Department of Commerce usually has a say in the sale of products or businesses to foreign countries that are deemed to be strategic or sensitive technology.  In fact, I got stuck in a situation where my employer was told specifically that we could not sell a CNC controller to a Korean customer.  That’s pretty small potatoes compared to controlling the supply of permanent magnets which influences billions of dollars worth of electric motors manufactured and sold all over the world.  So it strikes me as a little odd that the sale of Magnequench to its current owners, Neo Materials, was completed without a much discussion. leaving the US without a domestic magnet supplier.

There will surely be a lot of discussion about this situation at the conference, and I will be in attendance to get the latest information on the subject.  So look forward to a review of the conference in an upcoming post.

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Technology is a major driving force in the economy.  The ability to create whole new industries that have never existed before.

And there is a second driving force, sometimes made less obvious by the flash of the latest technical breakthrough.  Cost.  What is the relationship of cost to the development of industry?  As costs decline volume goes up.  Steel manufacturing per man year of labor increased 500% during a period of intense competition between the US and Japan.  And interestingly, one of the breakthroughs was the creation of the “mini-mill” which could produce specialty steels more cost effectively by making them in smaller batches.  Sometimes the solution is counter intuitive.  The steel industry was all about increasing batch size.  But serving the market with more complex products turned out to be easier with smaller batches, ultimately increasing overall sales and defending the US market to some extent from foreign competition.

Are there other cases where innovation was economically driven?  In the machine tool world the majority of manufacturers develop bigger and more complex machines so that a single machine can handle any operation.  This complexity tends to drive costs up quickly.  So the tendency is to find high performance machine tools costing hundreds of thousands of dollars.  In contrast, the HAAS company re-invented the machine tool business by focusing on making a low cost, high quality machine tool that many shops could afford to buy.  They were one of the first companies to have several models of machine tool in the $50K range.

They did it by concentrating on the economics of a machine tool that was profitable in operation.  That means a machine with a low cost to purchase, low operating and maintenance costs, and sufficient precision to meet the requirements of most operations.   In order to reduce their machine cost they had to develop their own controls platform.  They restructured everything in the design and manufacture of the CNC system to meet the cost objective.

In act, they are so successful, that HAAS is the largest CNC company in the western world.

Many similar situations exist in other industries.  In small plastic parts manufacturing there are a number of breakthroughs that have created lower cost parts in smaller batches based on innovative new tooling systems.  In metal fabrication there are new process like thixotropic molding and metal injection molding that have been developed to lower the cost of metal goods by making parts at lower costs.  These solutions are focused on reducing costs and other barriers to the entre of new products like tooling costs and minimum batch sizes.  And they represent major new markets that were not possible in the past, because they are focused on the economics of the industry they serve.  Decreasing the cost of entry and the cost of part manufacturing opens up new markets

So inventing the future can be technology.  Or as it can be economics.   It’s all innovation.  And it’s all about delivering value.

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The particular magentic material that has enabled the CD, DVD, Hard Disk Drive, high performance speakers, magnetic resonance imaging and many other technical wonders, is Neodymium Iron Boron.  Based on General Motors research on magnet materials (in the 1980′s), scientists found a particular molecule of these materials which exhibited extremely high magnetic strength.  And, of course, one of the immediate benefits would be reducing the size of starter motors in cars by 30% and the weight of the motors by even more.  Great stuff!

But making the molecule wasn’t exactly a picnic.  Alloying was easy, but it turned out you had to cool the material down suddenly in order to get just the right molecule to form in a powder and then sinter and magnetize the result.  A whole new process had to be developed, called spin casting, to cool the material quickly enough to generate high quality raw material for NeFeB magnets.   I’m sure there are a lot more technical details, but I don’t remember much from my tour of the GM Magnequench facility in Indiana.  It’s been several years.

NeFeB alloy has been dramatically improved and as demand has increased, fortunately, the price has dropped from the extremely high levels during it’s introduction.  As prices have declined it is estimated that 16,571 tons of Neodymium were used in magnet making in 2009 and 24,635 tons will be used by the year 2014.  That’s an increase of 48% in five years.  That’s huge.

The reason for all the increase is the fact that NeFeB magnets make really efficient motors.  So the new generation of appliance motors and air conditioning compressort that include NeFeB magnetics to increase the flux of the rotor combined with electric and hybrid car motors are driving demand more more magnets.  And now some emerging technology in the wind power marketplace, direct drive generators, will require many tons of additional material.

But what about our friends at GM Magnequench?  They’re gone!  The great future, full of potential for a US manufacturing company, lost to the sale of the company and closing the manufacturing facility.  GM sold the company to New Materials Technology in Toronto which is owned by China.  But the new owners couldn’t run the US factory at a profit.  Even at $20/hour for labor.  All the manufacturing jobs, gone.

There is currently no NeFeB magnet manufacturing in the US.  Which is kind of crazy when you think of all the applications we have for the stuff.  Even worse is the fact that a lot of advanced military hardware is dependent upon the magnets for guidance motors on missiles and a host of other applications.  And according to one source China now owns 97% of the world’s Rare Earth Elements sources.    Which is why there are now hundreds of companies in China selling magnets.

On the positive side, this has lead to overall declining prices for these magnets.  But will that continue to be the case?  The Chinese government is expecting to decrease their exports of magnets by 34% next year.  This could spell trouble for many companies.

But there is hope. The USGS has reported that the Mountain Pass Mine in Southern California is one of the largest and richest deposits of Rare Earths, including Neodymium, in the world.  And Molycorp is ramping up to fill the gap with new mining and manufacturing capacity.  Go get ‘em guys! Free enterprise at work.

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But it has to be said that the motor and drive solution for the electric car is not where the problem has to be solved.  Any motor can be made to run an electric car.  What is critical is how you apply it.  The starting conditions require high torque at low speed and the running conditions require low torque at high speed.  So, typically, what looks like a small 5 to 15 horsepower running requirement at full speed, becomes a 150 horsepower starting requirement depending on how quickly you would like to start.  If you want to keep up with a Corvette, it uses 450 HP to start.

And this produces a lot of confusion.  Why not use at 2 speed transmission to help the situation.  Fine, but the ones that are available can’t handle the dynamic response of the electric motor.

Can electronics help this situation?  Interestingly, yes.  There is a control algorithm generally called vector control which allows you to manage the rotor torque and stator torque separately.  By varying the phase angle between the two, like advancing and retarding the timing of a mechanical distributor cap on an internal combustion engine, you get different speed torque curves out of the motor.  COOL!  Is there any downside to this?

Yes.  You need more current to produce more torque.  That doesn’t change.  So you have to be able to supply the current, and you have to be able to manage the heat.  The heat is transitory since you only need the high current during starting, but it is best to have sophisticated software running to keep track of the RMS temperature of the motor.  Lower operating temperatures mean longer life and reduced risk of demagnetizing the motor.

So, yes, you can run an electric car with a garden variety AC motor, and with good electronics, you can make it run fairly efficiently.  With higher efficiency motors, the benefit is increased driving range from a given power source.  High efficiency motors are frequently smaller and lighter weigh, but a weight savings in the motor of 50 or even 100 pounds is not that big a factor in the driving range when the curb weight of the vehicle is 3000 pounds.

Basically, its F=ma.  If you can reduce the mass of the vehicle, you reduce the battery payload required to power the car.  Aluminum space frames, like on the Prowler, have been studied by the car industry and can reduce curb weight by 400 pounds and reduce cost by 10% at the same time.  We need to bring all the mechatronic leverage to the situation that we can, if we are going to make electric cars that make sense.  Before its too late for Detroit.

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Omron Electronic Components, LLC

A new highly portable mechatronic system to measure harmful pollutant relies significantly on a MEMS flow sensor

Figure 1. Stationary Aethalometers are used throughout the world, but have been too heavy to be truly portable until now.

Carbon dioxide is well known as a major contributor to global warming, and there are many ways to detect and measure it. But it is not the only culprit. Scientist have found that the second most significant contributor is soot, or black carbon. Not only does black carbon contribute to environmental degradation, but these tiny particles also cut short the lives of seniors and sicken children. A recent economic impact study in California’s San Joaquin Valley (The Benefits of Meeting Federal Clean Air Standards in the South Coast and San Joaquin Valley Air Basins, November 2008) has identified the cost of air pollution and estimated it at more than $1,600 per person per year.

Black carbon doesn’t stay in the atmosphere as long as carbon dioxide, so controlling it has the potential to achieve major benefits in the short -term. Some of the major emitters of black carbon are diesel engines plus wood- and coal- burning fires. However, to analytically determine the source of black carbon and recommend effective changes to correct the problem, scientists require instruments capable of measuring black carbon in the field.

Manufactured by Magee Scientific of Berkeley, CA, the Aethalometer, is an instrument that uses optical analysis to determine the mass concentration of black- carbon particles collected from an air stream passing through a filter. However, until recently, these instruments were too large and bulky to be easily moved to a suspected point of origination for black carbon; the smallest device (the AE42) weighed approximately 25 lbs and measured 11 x 12 x 8 in. The instruments collect data from installations located around the world (Figure 1), but these only give scientists local samplings.

To get a complete picture of the black-carbon problem, scientists required a very small portable Aethalometer to easily determine black- carbon readings in almost any location. A reduction in size required some clever engineering and component sourcing.

Figure 2. The AE51 Aethalometer’s designers took advantage of the flow sensor’s port placement by designing the manifold to interface to them directly without tubing.

Aethalometer operation

Aethalometers function by measuring the amount of particulate deposited on a fiber filter by a specific amount of air passing through the filter for a predetermined amount of time. This mechatronic system needed to incorporate mechanics, electronics, and computing in one compact package. One of the major size reduction obstacles to overcome was finding a small, lightweight, highly accurate flow sensor with low power consumption. Having worked with Omron in the past, the engineers from Magee Scientific again called on Omron for a solution to their requirements, and the company recommended its D6F-P MEMS mass flow sensor for gathering the required air samples.

Figure 3. D6F-P flow sensors are individually calibrated before shipping to deliver excellent repeatability results.

Size and power constraints

The body of the D6F-P measures just 10 mm high by 23.3 mm wide by 27.2 mm deep, and with a weight of just 8.4 grams, it fell within the size and weight restraints set forth by Magee. Designed for easy installation, the D6F-P has both the input and output ports on the same side which facilitates the connection of tubing.

Magee engineers made clever use of this feature, designing their new AE51 Aethalometer so that the sensor ports would mate directly to their manifold, without the need for tubing (Figure 2). Since this miniature Aethalometer was to be battery powered, current consumption was a concern. The D6F-P proved to be very efficient, drawing a maximum of only 15 mA while operating on 5 Vdc.

Accuracy and repeatability

The AE51 relies on calculating the exact amount of air, driven by a blower incorporated in the device for a given time. Therefore the flow sensor would have to be very accurate. The D6F-P’s flow range/ pressure range of +1.0SLM (+0.84 in H2O) with an accuracy of ±5% F.S. maximum and ±2% F.S.

typical would deliver the precise flow readings Magee required to obtain reliable measurements.

Additionally, since the sensors are individually pre-calibrated at the factory for high repeatability, Magee Scientific’s finished device adjustment and test time was kept to a minimum (Figure.3). Durability was also a concern since the AE51 would have to take multiple readings, but the sensor’s MEMS technology has been proven to deliver a long life with excellent repeatability.

Figure 4. A patented dust segregation system with dual centrifugal separators ensures that the sensing chip remains clean.

In the real world

Since the AE51 is designed to measure black- carbon particulate in areas of known high concentration rates, the sensor had to be reliable in these dirty, real- world environments. Measurements would need to be taken at busy traffic intersections, bus stops, industrial sites, and coal-burning power plants.

The AE51 would also be used in remote areas of the world where use of wood fires to cook and heat is common. Although the filter used to measure the density of the black carbon is in front of the sensor’s inlet, if any particles that got past were to effect sensor operation, measurement accuracy would be compromised.

Figure 5. The reduced size of the hand-held AE51 is obvious when compared to the rack mount AE22 Aethalometer behind it.

To prevent that occurrence, the D6F-P design uses a patented dust segregation system (DSS). The DSS in the flow path incorporates dual centrifugal chambers, in which particulate matter follows in the outer path away from the MEMS sensor chip regardless of the flow direction. Thus there is practically no degradation in sensor performance over the lifetime of the system.

Keeping the MEMS sensor chip clean lets Magee guarantee a long life for their Aethalometer without worry about black-carbon build- up harming the device’s performance (Figure 4).

The A51 Aethalometer (Figure 5) is so small that it can be strapped to a user’s belt, enabling the user to become the instrument’s legs and freeing the user to do other work while the meter is gathering information. It can also be tethered to weather balloons for upper atmosphere readings. Another potential application would allow the device to be carried by those whose health might be affected most by inhaling large amounts of black carbon. The AE51 would alert them to areas that have high concentrations of this toxic material.

Omron Electronic Components, LLC

www.components.omron.com

Mechatronic Tips

In the beginning of September, a press release came to my e-mail inbox that really caught my attention. Considering the facts that (1) I get hundreds of e-mails every day, (2) most are about a “new product that is the [first, smallest, fastest, least expensive, most powerful] of its kind”, and (3) I’ve been in the tech journalism business since Ben Franklin started flying kites, it takes something pretty unusual to stop me in my tracks.

The release was from a company called Vector Fields, a part of Cobham plc based in Aurora, IL, and it was announcing the release of design tools to help RF designers exploit the properties of metamaterials. The tools are part of its work for the Advanced Materials for Ubiquitous

Leading-edge Electromagnetic Technologies (AMULET) research project, which is a three-year £3.4m collaborative R&D project funded in part by the UK’s Technology Strategy Board. The project is led by a consortium consisting of Vector Fields, Cobham’s ERA Technology, the National Physical Laboratory, and Queen Mary University of London.

Metamaterials are a fairly recent class of engineered materials that were first conceived at the end of the last millennium by Rodger M. Walser of the University of Texas at Austin. He defined metamaterials as: “Macroscopic composites having a manmade, three-dimensional, periodic cellular architecture designed to produce an optimized combination, not available in nature, of two or more responses to specific excitation.” Recently, there has been theoretical discussions about developing cloaking materials that can bend light around objects to make them invisible.

Obviously, such materials could have a significant impact on warfare and armaments, and so the U.S. Defense Advanced Research Projects Agency has been funding development since 2001. DARPA says it has completed this project, but given the nature of the agency’s activities, details are hard to come by.

Getting back to AMULET, Vector Fields’ role in program is to provide antenna developers with enhanced design tools to simulate metamaterial structures. The first phase of this support is currently being released to the market in the new version of the high-frequency electromagnetic design tool, Concerto. One of the key problems addressed by this software, according to it’s developers, is the need for efficient and fast simulation. Concerto handles this by exploiting the periodic nature of passive metamaterial structures to minimize the computations required. The AMULET project will also be exploring the use of active metamaterials, and Vector Fields intends to add modeling support for these in future developments.

There were several things about the announcement that made me take note. First of all, this was about the practical application of metamaterial to engineering problems not of a military nature, but of key commercial importance to everyone involved with wireless technology. Further, the tools are not just for a few researchers working on stealth projects, but for anyone who would like to get involved with this game-changing technology.

And there is no doubt that metamaterials are game changing. The properties of metamaterials are directly dependent on both their physical parameters and their electrical characteristics, and designs based on such materials must take both physical and electrical properties into account simultaneously if it is to be done at a practical pace. The fact that tools are being developed as part of the AMULET project is a clear indication that traditional approaches will not succeed with this
new technology.

If these new materials and tools create the revolution in design that I believe they will, it will certainly mean that we cannot go forward without mechatronics. It will become impossible to create a competitive product without simultaneously engineering its mechanical, physical, and electrical attributes. What’s particularly encouraging is the fact that those working in the field seem to realize that tools must come first, so as to allow designers to completely explore possibilities quickly and thoroughly, and thereby avoid most of the trial and error approach which has hampered development in the past.

Mechatronic Tips