Unique Solutions in Material Handling

Moving products around is mechanical work.  When the work is done by a control system and actuators its mechatronics.  Mechanical work, whether by humans, by horses, by hydraulics, electrics or whatever, is still work.  Figuring out what technology approach will be the most cost effective way to get the work done is the challenge.

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.

Semicon 2010

This year’s semiconductor industry gathering, Semicon 2010 is over.  And it was a good show with a lot of technical content targeted at the ongoing effort to achieve ever higher density parts.  The forecast for 2010 and 2011 is for the highest growth levels in a decade.  Certainly, at $295 Billion in projected sales for calendar year 2010, the semiconductor industry is the largest economic activity in the world. And it is just as certainly a more significant economic activity in the US economy than the automotive industry.

Which is saying a lot.

Some of that economic activity is the obvious stuff.  Jobs.  Making things that are important to the industry.  Like all the silicon ingot, water treatment, chip encapsulation compounds, chemical solvents, and gases that are needed.  And all of those feedstocks require people in their respective industries.

There is also the capital equipment market.  Companies that make machines that make chips.  Machines that grow silicon ingots, machines that slice silicon into thin wafers.  Polishing machines that make the surface smooth enough to create the nanometer sized features that become semiconductors.  Wafer probing machines that do functional testing, dicing machines that slice the wafer into the single chips, wire bonding the bare die into lead frames to we can attach the circuits.  Encapsulation, labeling, testing and packaging the final products.

The Semiconductor Industry Machinery business is estimated to be an $11B activity separate from the sale of chips.  The semiconductor equipment market is still the largest target market for motion control products and mechatronics of any market I know of.  At a close second place would be the electronic assembly machinery market  with it’s pick and place, adhesive dispensers and inspection machinery.

Interestingly, the semiconductor industry also provides trickle down technology.  Hard disk drive spindle motors require the exact same 3 phase brushless drive and control as industrial servo motors.  The difference is that the spindle motor is manufactured in quantities of tens of millions of units.  This allows disk drive manufacturers to explore the ultimate boundaries of cost reducing the technology and introducing new techniques to improve performance.  Much of this technology has migrated to the motion control industry in the way of integrated motor control chips.

The semiconductor industry is now made up of two major markets.  Chips and Solar Cells. The solar cell market is counted separately and does not overlap with traditional semiconductor business.  Many of the companies that make semiconductor machinery have extended their capabilities to the solar industry as a way of diversifying into new markets and making up the lost ground that was experienced in the machinery business.

While Solar is still an emerging industry to some extent, it will continue to drive large segments of the economy. Solar photovoltaics and solar hot water drive a lot of jobs in manufacturing and installation of systems.

What we need in the public policy sector is better understanding of the business needs that these industries require.  Generating enough electricity for these industries to thrive is one requirement.  And most states in the US have failed to bring any new capacity on line over the last 30 years. States that recognize these needs and are willing to meet them are going to be the States that prosper with low unemployment and thriving economies.  And that’s where we all want to be.

Intersolar 2010

Intersolar 2010 is one of the larger gatherings of the Solar Energy industry.  I had the opportunity to attend InterSolar 2008 when it was still relatively new.  In the last two years the Solar Energy industry has grown very quickly, chalking up 35% growth in 2009 over 2008 and with similar forecast growth for 2010.  Overall revenue generated from the sale and installation of solar energy systems in the US was estimated at over $2.4 billion.  This is made up of solar panel sales across the residential, commercial and utility customer projects with a mix of technology including some solar hot water systems, some large scale solar concentrator systems and a whole lot of solar panels being installed with racking, inverters, tracking systems, engineering design, contractor labor, etc.

The contrast between InterSolar 2010 and 2008 was very noticeable.  This year’s trade show reflected the growth and sophistication.  Tremendous effort is being put into every aspect of the photovoltaic technology, tandem junction semiconductors that produce the photovoltaic effect at 2 different light frequencies, enhanced surface texturing of the surface glass to improve transmission of light and reduce the problem of incident angle of light, new chemistries like Copper-Indium based photovoltaics which are now “printable” as ink coatings, and ongoing development of thin film silicon, concentrated light focusing on silicon, recycling of the silicon itself, and a host of improvements all targeted at reducing the cost of producing electricity from sunlight.  As you might expect, incredible support from semiconductor equipment makers to provide new equipment to make the technology scalable in production and cost effective in the marketplace.  Solar is the new growth engine in semiconductor equipment.

Solar Panels, like other types of semiconductors, are subject to decreasing cost with increasing volume.  In typical Semiconductor Industry fashion, a lot of capacity has been ramping up since early 2000 which led to a 40% correction (read “drop”) in the price of solar panels during 2009 which played havoc with project bids and created serious difficulties for distributors with inventories or contracts for solar panels at the higher prices of early 2009.  However, now that prices are lower, more demand is expected, and hopefully, companies that had a tough time during 2008-2009 will find business conditions in 2010 and 2011 more favorable.

There is continued optimism that the US solar market will continue to grow at 30%+ per year for the next couple of years, some forecasts are 50% per year and one forecast from Europe suggests 100% growth in the US market next year.  Huge growth forecasts combined with caution on the manufacturing side has created shortages and long lead times for new deliveries.

But we should note, with caution, that this market is largely subsidized by State Renewable Energy Portfolios mandating the alternative energy systems, Utility Company Rebates and Federal Tax Incentives.  Solar energy technology is generally sold on the basis of avoiding future increases in energy costs, not on the basis of eliminating energy costs.

So there is still a big gap in bringing electricity costs down using solar power.  Modern coal plants produce electricity that the utility company can sell at a profit for 6 cents per kilowatt/hour.  By comparison, a 300 watt solar panel will cost at least $1500 installed and functioning.  It can only produce about 756 kilowatt hours per year, and even at 12 cents per kilowatt/hour, won’t break even for about 16 years without government incentives.  So you’re not eliminating your electric bill, you’re prepaying it with a bank loan for a bunch of equipment that doesn’t burn coal.

That’s OK if you can afford it, just don’t make the mistake of thinking you are getting rid of your electric bill.   But be on the lookout for the next breakthroughs in solar.  They are coming.

Linear Actuators

Linear Actuators are a class of mechatronic systems with some unique design constraints.  As a result there are dozens of approaches, dozens of vendors, the option of designing the actuator from scratch, and, frankly, a lot of confusion.  The problem lies in the fact that the actuator as a subassembly is the combination of a number of separate technologies.  This means there are a number of design tradeoffs incorporated into the resulting actuator that must be acceptable in order to use that actuator.

Categorizing linear actuators is not entirely straightforward because many categories overlap.  The “motive power” category can be any type of power source, rotary motor or linear motor powered.  Linear motor solutions are much more commonplace in linear actuators today due to declining costs for this technology choice.  But in a linear motor based actuator, the linear motor is both the motive power and the mechanical transmission at the same time.

Categorizing linear actuators by their mechanical transmission style is another approach.  The most common categories are screw type, belt and linear motor.   But the motive power for a screw based actuator could be a stepping motor or a servo motor.  The stepping motor is predominant because of it’s suitability for positioning, but it may be underpowered for some applications where a servo is needed.   So the linear actuator transmission category can have overlaps because of the different motor types that are used in conjuncion with it.

Price seems to be one means of eliminating the ambiguity.  Stepping motor and lead screw combinations are popular because they are economical and maintaining 0.001″ accuracy is very easy.   Linear motor systems are capable of .5 micron accuracy with little or no friction, acceleration and speed that is incredible, but generally the higher performance comes at a higher price.

But in the end, the selection process is best guided by the criteria of the application.  The list is, thankfully, short.  Load weight or force that must be generated, speed, accuracy and life expectancy or number of cycles of operation.  This last is probably the key determinant in system selection.  Long life or high cycling goals lead to linear motors actuators with little or no friction. You have to familiarize yourself with the overall field because the tendency of confusing the technology and the application needs.

At the recent Semicon gathering of manufacturers involved in semiconductor manufacturing, a lot of attention is given to the mechatronic content of machinery.  And as far as I have been able to determine from many different market research projects, semiconductor manufacturing is one of, if not, the largest market for mechatronics every.   So it’s also not a surprise that a lot of vendors come to the Semicon show with their latest and greatest product offerings.

Among the most interesting, Nanomotion continues to extend the reach of piezoelectric linear motors, yet another technology choice within the linear actuator sphere.  Piezo motors have only one moving part, and meet the high precision, high reliability criteria.  With increasing usage, there has been decreasing cost for this unique solution, along with superior position feedback technology and excellent packaging for space constrained applications.

In addition, IKO has released a number of new linear actuator assemblies, both screw driven and linear motor driven.  They are also showing a number of unique 2-axis configurations one of which is the thickness of a tape reel and is targeted to unloading parts for electronic pick and place machinery.

Brilliant examples of manufacturers continuing to integrate mechatronic technology to make it more convenient for the customer.

Mechatronics as Process

There are three basic disciplines of control.  Discrete control which generally relates to making a product or dealing with sequential and event driven logic, process control which deals with the conversion of raw materials into more complex bulk products, and real time control of things like electric motors.  In general, discrete control is not really time based, although there are exceptions. Process control is based on longer time periods due to the nature of the large batches of material that are being processed and the associated thermodynamics.  The hardest of all real time control in the case of electric motors which requires nanosecond capability from the embedded control system to achieve the performance needed by energy conserving systems.  As a by product of the different time bases, each technology has grown into it’s own discipline and control philosophy.

Occasionally the line between mechatronics as the design of mechanisms in discrete manufacturing and applications that are more process oriented blur the neat categories of the major control disciplines. More and more control system requirements involve the blending of 2 or 3 different types of control into a single architecture.  This creates subtle problems in order to properly architect the system so that the final effects are achieved.

Polishing and grinding, for example, appear to be positioning applications.  A grinding wheel or buffing wheel must be brought into position to make contact with a workpiece.  So the normal control system behaviors must be dealt with in order to achieve position.  But positioning the tool is only the beginning of the process.

How do we measure the process of grinding or polishing?

And most importantly, how do we know when it is done?

The process of grinding or polishing is a matter of torque in the application of the working tool to the workpiece it is in contact with.  Generally through an electric motor that is turning the tool.  By measuring the torque, which is current in the motor, we can know that the actual process is being achieved.  It may require empirical measurement to determine how much torque is required to achieve the proper surface finish, but there is a direct correlation.  Too much current means the tool is buried in the part, too little current and there is no work being done.

But at this point, there is a process that can be controlled.  If the proper torque level is applied through the motor the runs the tool, there is also a corresponding value as the contact is reduced that indicates the completion of the process.

This behavior is completely separate from the position of the tool.  However, if there is reduced contact with the workpiece due to the tool wearing out, that is, the size of the tool has decreased slightly, then the positioning system has to be updated to compensate.

These are simple concepts, but they are often overlooked.  Ironically, there are many applications that require close consideration of the mixed control methods.  Chemical mechanical planarization of silicon wafers suffers from similar difficulties with the need for extraordinary precision in polishing the surface of the wafer.  Do we really know when the process is done or do we just leave it running an extra 20 minutes just in case?

There’s always room for improvement.  And some of the recent control system innovations are delivering significant performance that should be considered as we pursue new applications.

Solar Power and Economies of Scale

If solar power costs decline to “grid parity” or the same cost as generated electricity costs at the grid, it will take over a significant portion of the utility industry.  That has been the goal for 20 years.  It’s a great idea.  Because eventually homeowners can generate their own electricity, become independent of the utility and reduce their operating costs.

Or so the story goes.

We’ve been trying to reach grid parity for some time.  Without much success.  And not because we aren’t trying.  Billions of dollars of government subsidies, R&D funding and private investment are being poured into the pursuit.

Energy independence!  Both as a Nation and as individuals.  It would be great to be able to say, personally, we don’t have pay any utility bills.

The first great fallacy is that either solar power and wind power can cause energy independence for the US.  This is because the energy we depend on is not electricity, it is Middle East Oil for gasoline.  We are dependent because of our cars and the choice to not make our own gasoline, even though we can at lower cost than importing it.

But on top of that, almost none of the electricity generated in the US uses Oil.  It’s all coal, natural gas, or nuclear.  So the idea that the US will reduce it’s foreign oil imports by generating electricity with solar power or wind power, is completely ridiculous.  There is no connection between the two.

There is a theoretical energy equivalency that can be expressed.  But there is no real connection.  So people who make this claim are intentionally misleading anyone who listens.

How are we doing with respect to the cost of electricity generated by solar power?  It’s been an interesting couple of years.  The industry experienced a brief shortage of raw silicon which kept prices fairly high.  More recently there was a precipitous drop in panel prices.

Opinions vary as to the cause of this drop, but with the massive increase in manufacturing capacity worldwide, I would guess that the price drop is strictly a matter of oversupply.

Economies of Scale will fix the problem according to some.  After all, look how well we’ve done with computers, hard drives and flat screens. Flat screens that were $10,000 to $50,000 a decade ago are now affordable to the point where the CRT has become obsolete.

Since the biggest component cost of the solar panel is silicon wafer, we should expect similar results in the solar market.  The stampede to build more solar panel manufacturing plants resulted in oversupply.

Now the race continues to drive costs down.  Panels that were selling for $3.50/Watt a year ago are down to $2./Watt and prices are expected to continue to fall. And some manufacturers will not be able to keep up with falling prices using older technology.

But are we getting to grid parity?  Is Solar power cheap enough to compete with utility power?  Nope. Because even at today’s bargain pricing, a 225 Watt panel will only produce 900 kilowatt hours in a year at maximum efficiency.  At market cost for electricity, $.05/kW, it’s only $45 worth a year.  And it currently costs about $1125 pay for the panel, installation and balance of system components.  That means it will be around 25 years, the end of the useful life of the system, before it breaks even.  Yes, in California where consumers pay $.23/kW the payback is better, but it’s still very expensive to convert to solar.

We have got to do better than that.  And we will.  The technology is coming along.  But economies of scale by themselves can’t quite get us there.

Magnetics 2010 and Motion, Drive & Automation

There is a small industry conference that takes place every year with a lineup of industry experts that is top notch by any standard.  It’s called the Motion, Drive and Automation Conference put on by E-Drive magazine.  This year it is located at the Disney Hilton Resort in Orlando and is taking place on January 28 & 29.   The conference includes a wide range of industry experts from many fields of advanced electric motor design, advanced motor control concepts, power semiconductors and state of the art motor testing system.  There will be a lot of technical and product presentations that showcase leading edge technology in electric motors, precision gear reducers, new technology for motion sensing, and a number of improved power semiconductor devices for the motor control industry.  This is a great place to get up to date on the latest technology that will impact of motor and control technology across many industries over the next few years.

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.

Chips, Chips, Chips

Semiconductor manufacturing is still a little bit like magic.  It’s hard to imagine packing millions of transistor into tiny spaces and creating  cellphones, computers, flat screen television, digital cameras, CD players and so forth.  And the industry keeps pumping out the innovations.

And there are so many technologies, all focused on solving application problems but balancing the economics of development cost and manufacturing scalability.  Where would the Oui or iPhone be without accelerometers that are really inexpensive?  Fax machines without G3 communications chips,  or $49 printers without stepping motor chips and ink jet controls?  All benefits of high volume economy of scale.

Industrial control systems have generally required chip technology, but in numbers of chips considered too small to merit custom designed solutions.  But the Rockwell Control Logix concept breaks the partitioning of applications by applying the same control processor to all kinds of control equipment, variable frequency drives, programmable controllers, HMI’s, you name it.

Is there an ultimate chip?  A chip solution that does everything?  Not really.  But the wizards of the microcircuitry world keep coming up with new architectures.  New approaches to existing applications that offer price or performance attributes that will hopefully trigger lots of new designs that result in breakthrough products.

Recent trade press is buzzing about a new processor that combines the logic solving capability of FPGA (Field Programmable Gate Arrays) with ARM (Advanced Risc Machines).

FPGA excels in the ability solve logic, and has scaled up to massive numbers of gates and tremendous processor speeds to solve enormously complex applications.  Even applications requiring real time operation like motor control can be solved through FPGA with proper attention to detail.   Applications that were considered impossible a few years ago are now within the range of these processors.

But using gate arrays may not be the most efficient way to do motor control.  Hard real time motor control requires a great deal of analog processing to monitor conditions in the real world (like voltage and current) and the ability to respond to dynamic changes through complex programming and mathematical models.  Much easier for ARM processors with super efficient instruction sets and single cycle multiplication and division.  In some designs 16 channels of high resolution A to D converters and direct PWM capabilities.

So combining the two technologies seems like the ideal solution for a huge range of industrial control applications.  And if you get it all in one processor, wouldn’t that be great?

I  can’t wait to see what new product developments take place in the next few years with this kind of processing power available.

Solar Power, Mechatronics and Economics

At the recent Semicon show the big buzz was about the emerging Solar Energy industry. Lots of “new” products, lots of buzz. The big semiconductor machinery manufacturers who view crystalline solar cells as a stimulus to the demand for machinery and silicon have put in a lot of effort. The main goal? Get the cost of the solar cells down to where electricity produced with silicon is comparable to the cost of electricity generated by fossil fuel.

And, in fact, the industry is getting there. The current estimates are that solar power is costing about the same as peak demand consumer power, $.23/kWh. And with the current wave of investment and scale up, something which the semiconductor industry has always done well, there is serious forecasting that the cost of solar electricity will continue to fall. Read more

Mineral Insulated Thermocouples

Versatile mineral insulated (MgO) thermocouples are constructed with the thermocouple element compacted in high-temperature magnesium oxide and protected by an integral metal sheath.

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