Motion Control System Includes Solid-State, Embedded PC

Siemens announced that an embedded PC is now available for its Simotion® P320-3 motion control applications. Providing maintenance-free controls, the Simotion P320-3 brings the power and simplicity of a PC to motion control.

The embedded PC, which features a DDR3 memory and an Intel Core2 processor, is free of wear from moving parts, such as hard disks and fans. This compact motion control system provides maximum flexibility and accommodates centralized or decentralized machine concepts for PC-based applications or for applications that require a compact size.

It is designed for many different motion control applications with its multiple onboard interfaces. They support communication over Profinet, the open industrial Ethernet standard, as well as Ethernet interfaces that run at 10 / 100 / 1000 megabit speeds. Four USB interfaces make it simple to connect a keyboard, USB stick, printer or other devices. A DVI port rounds out the links so users can attach a display or monitor. The Simotion P320-3 can also be used in a “headless” configuration without a display, monitor or front panel.

LEDs on the front indicate the operating states, making self-diagnosis easy. The integrated power supply bridges temporary power failures. In the buffered SRAM memory, the process data is saved securely even in the event of a sudden voltage drop. Monitoring functions for the batteries, temperature and program execution are also included. The Windows Embedded Standard 2009 operating system, which increases the reliability of the system, is pre-installed. Additionally, the Simotion runtime system comes installed on the Simotion P320-3.

www.sea.siemens.com

Superior Feedback Performance in Telerobotics

WITTENSTEIN has perfected its control loading products to provide realistic force feedback for the telerobotics market. Utilizing compact design and unique electronic linking, sidestick systems from WITTENSTEIN offer revolutionary reliability and realism for operators.

WITTENSTEIN Aerospace & Simulation has been the control loading leader in the flight simulation market for more than a decade. The Company has taken its expertise and applied it to telerobotics, where a user controls an axis or entire vehicle remotely. WITTENSTEIN’s products provide the user with feedback of the remote axis through electrical linking and force control technology.

The main features of the sidestick systems for telerobotics are superior efficiency, compact design, and electric linking with force feedback. These result in smooth operator feel, no need for additional mechanical linkages or hydraulics, and a standard off-the-shelf system solution that utilizes standard wall-outlet power. The robust nature of the WITTENSTEIN systems allow for up to 10 axes per control module.

Sample areas of application for this technology include remote product testing for reasons due to environmental or equipment restrictions.

www.wittenstein-us.com

Robots and the Future – Part 2

Robotics researchers have been pushing the envelope for the last 30 years since the inception of “artificial intelligence”.  The basics of artificial intelligence programming is the modeling of human expertise and mimicking human behavior in a variety of circumstances.

One aspect of artificial intelligence gave rise to expert systems.  Complex systems like diesel locomotives are very difficult to repair because of the large number of parts operating together.  Human experience accumulated after years of working with diesel locomotives needed to be captured in order to prevent each generation from having to apprentice workers over long periods of time in order to learn how to troubleshoot these systems. So programmers in the early days of AI were employed to learn and program the diagnostic procedures developed by skilled workmen over many years.

These programs were very successful.  But in no way do they replace human intelligence and insight.  This is simply an example of subtlety in programming a specific area of human experience.  Speech recognition continues to be a challenge after decades of effort, limited to transcription applications and simple material handling instructions.

Another area that came up was large scale logistical mapping, another Expert System.  What is the most economical way to use airplanes to transport people around the US?  When you think of a large air carrier and the number of airplanes, flights, destinations and how they might be mapped together to get the best use out of the airplanes, it is a problem that is too large and complex for a single human to work with.  Enter the expert system programmer.

But in none of these cases can a computer program exceed the boundaries of it’s programming.  Can the autonomous Jeep get from it’s starting point to it’s destination?  Yes.  With many man-years of programming and a vast array of computing power, proper deployment of sensors and actuators, and a lot of stored energy.

Can the autonomous Jeep perform any other task?  No.  Regardless of the sophistication, the machine cannot exceed the boundaries of it’s programming.

Can we teach machines to learn?  So far, only in the most crude and rudimentary way.  But the course of the learning is again bounded by the programming.

And again, I will defer discussion of true intelligence or consciousness.

But what robotics can do to expand it’s usefulness is to mimic simple human tasking where it is cost effective and where the robot can “outproduce” or exceed the precision of a human.  Robotic welding, for example, has reached the point where a basic robot welding cell is less than $50,000.  So the cost of entry, the learning curve and complexity of implementing a welding robot cell in a small production facility is very reasonable.

Will robots be used in “human service” applications?  Sure.  ”Robot, vacuum my living room”  No sweat.  We can already do that with a Roomba only it doesn’t have voice recognition yet.  We have robots that can mow the grass in the front yard and avoid shrubs and trees.  Very cool.

Will we have robot servants like C3PO in Star Wars?  Hopefully more intelligent, C3PO was kind of dumb.  Simple tasks like serving a drink at a bar? Yes, that’s been done too, although it doesn’t have philosophical conversations with customers.

Will robots be able to provide basic care in hospitals and for the elderly?  Anything is possible. It will come down to how far we can push the envelope of programming, safety and return on cost.  Certainly we get robots to get a cold beer from the fridge.  But if the fridge is empty can it run out to the store and get us a six pack?

Not anytime soon.

Robots and the Future

In the field of Robotics, where is the line between between remote control, software control and autonomous control?  (No, I’m not going after the consciousness thing, it’s way too complicated)

Part of the problem may have to do with our use of the word “intelligence”.  We talk about the increasing “intelligence” of processors and particularly about the cost of “intelligent” control dropping to the point where it is suddenly economical to put a microcontroller together with a motor in order to achieve new levels of performance in either energy management or some other critical parameter.  Which opens new performance capability in robot design.

Increasingly, industrial robotics involve the use of vision systems to acquire information about the location and orientation of parts so that the robot system can interface smoothly to the “real world”.  If any of you have been to an industrial trade show and witnessed the Delta Robots making cookies, it is a very impressive sight to behold.  Incredible throughput and accuracy.  And that’s what it’s all about in industry. Higher productivity, improved product quality.

But where is the line between remote control and automatic control?  A remote manipulator for working in the nuclear industry, which was the big application that drove early robots, is a remote servo loop operating a series of servo motors and controls and powering mechanical systems, in order to do work that is dangerous to humans from a safe distance.  The DaVinci medical robot is a phenomenally improved version of the same thing.  A remote controlled robot, guided by direct haptic inputs from a surgeon, and with very sophistical tactile feedbacks, whose end effectors operate a variety of surgical instruments and actually increase the precision and speed with which doctors may perform certain procedures.

Is this a robot? Sure!

When we watch welding and painting robots making cars, we are watching decades of technology development in action.  There has been significant effort to improve the actuator hardware, and probably many man-years of software development to improve our description of the task and its safety and performance constraints in order to create not only reliable, but increasingly efficient machines to do the tasks that humans cannot compete with for productivity.  These are very sophisticated automatic applications, but certainly not autonomous.  The boundaries of the application and the programming for it are very finite.  Again, its about repetition, speed and accuracy.

And, yes, we call these robots, too.

But increasingly, there is discussion about the next frontier of robotics.  Where are the next big apps coming from?  Most of the big robotic companies in Japan and Europe are talking about personal service robots.  You can let your imagination run wild here.  Anything is possible. Certainly the service robot for NASA is interesting because it, again, follows the concept of doing tasks where it is difficult for humans to operate.

Is a Jeep that can be programmed to find a path and drive from one place to another autonomously a robot?  Yes, but we may be pushing the boundaries here just a bit.  These applications fall into the realm of Artificial Intelligence.  The programming and software languages for which were just being described for the first time about 30 years ago.  And at this point we are forced into the debate about what is intelligence.  In addition, are these systems which are capable of “learning” and what is learning exactly?  And more importantly, as all good science fiction movie watchers will ask, can a machine exceed it’s programming?  (See?  I didn’t even start on consciousness yet)

These are all serious considerations for the Future of Robotics which I will pick up further next week.

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.

Out Of The Gait: Robot Sets Untethered ‘Walking’ Record

The loneliness of the long-distance robot: A Cornell University robot named Ranger walked 14.3 miles in about 11 hours, setting an unofficial world record at Cornell’s Barton Hall early on July 6. A human – armed with nothing more than a standard remote control for toys – steered the untethered robot. Ranger navigated 108.5 times around the indoor track in Cornell’s Barton Hall – about 212 meters per lap, and made about 70,000 steps before it had to stop and recharge its battery. The 14.3-mile record beats the former world record set by Boston Dynamics’ BigDog, which had claimed the record at 12.8 miles.

A group of engineering students, led by Andy Ruina, Cornell professor of theoretical and applied mechanics, announced the robotic record at the Dynamic Walking 2010 meeting on July 9, in Cambridge, Mass.  Ruina leads the Biorobotics and Locomotion Laboratory at Cornell. The National Science Foundation funds this research.

Previously, students in Ruina’s lab set a record for an untethered walking robot in April 2008, when Ranger strode about 5.6 miles around the Barton Hall. Boston Dynamics’ BigDog subsequently beat that record.

One goal for robotic research is to show off the machine’s energy efficiency. Unlike other walking robots that use motors to control every movement, the Ranger appears more relaxed and in a way emulates human walking, using gravity and momentum to help swing its legs forward.

Standing still, the robot looks a bit like a tall sawhorse and its gait suggests a human on crutches, alternately swinging forward two outside legs and then two inside ones. There are no knees, but its feet can flip up – and out of the way, while it swings its legs – so that the robot can finish its step.

Ruina says that this record not only advances robotics, but helps undergraduate students learn about the mechanics of walking. The information could be applied to rehabilitation, prosthetics for humans and improving athletic performance.

Cornell University
www.cornell.edu

Bishop-Wisecarver Promotes National Sales Manager

Pittsburg, CA - Bishop-Wisecarver Corporation announced that National Sales Manager Michael McVeigh has been promoted to Vice President of Sales. He will have the primary responsibility of overseeing the entire sales channel for Bishop-Wisecarver, and manage all global efforts both domestically and internationally.

“I have had the pleasure of working with Mike for four years as our National Sales Manager. He has done a fabulous job of growing our sales efforts, even during the recent economic downturn,” said Pamela Kan, president of Bishop-Wisecarver. “The Board of Directors felt that bringing Mikes’ management skills to our entire sales channel will be an important element of our global sales efforts going forward. I look forward to working with Mike on our strategic sales plans for growing our sales both domestically and internationally.”

McVeigh is a college graduate from the University of New York at Buffalo. Prior to joining Bishop-Wisecarver in 2006 as the National Sales Manager, McVeigh worked in the bearing industry for 16 years in both sales and marketing. Since his hire at Bishop-Wisecarver, he has grown to appreciate the uniqueness of Bishop-Wisecarver’s customer base and their applications.

“Our overriding company goal is to become the customer’s 1st choice,” said McVeigh. “I am honored to be leading our team to meet this challenge as the Vice President of Sales.”

Bishop-Wisecarver
www.bwc.com

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.

Gears Boxes and Life Expectancy

Gear boxes are a complex subject in their own right.  The equations of motion required to generate gear teeth are pretty complicated.  And the issues associated with gear box reliability are even more complicated.  The parameters of merit are precision and load capability.  But cost is always a factor, and ultimately every system’s performance must be measured within the context of its life expectancy.

One of the most complex parts of the automobile is the transmission, which is a multistage gear reducer that “tunes” the speed range of the engine to the desired speed range of the vehicle at power levels of several hundred horsepower.  What makes this so extraordinary is that the workings are almost entirely automatic.  And the gearbox life expectancy is huge.  I just sold a 15 year old car and it’s transmission system is still working perfectly.

Manufacturing processes associated with gear manufacturing have evolved to help deal with the various demands for performance at lower costs.  The traditional method of gear cutting using machine tools generates accurate parts, but metallurgists found that the grain of the metal cut by machining caused weakening of the gear tooth.  Powder metallurgy had been progressing to the point where it was more cost effective to mold gear profiles in sintered powdered metal and do only finish surfacing with machining processes.  Later improvements in the process include the ability to load higher strength materials where needed in the design to produce higher strength parts at lower cost.

But as load requirements increase, all of the performance issues are magnified.  And unique environmental conditions can play a part as well.  In the current design of horizontal wind turbines, the gear box design is a critical component.  The gear requirement at 2.5 megawatts is certainly a challenge, but adding the need for precision and and durability to survive 25 years of operation make the task incredibly difficult.

There are a couple of subtle aspects to gearbox operation that need to be considered.  One is reversal stress.  How does one calculate reversal stress?  It’s the absolute value of the power, two times the power for simplicity, divided by the time period of the reversal.  This is usually a really big number.  And as the time allowed for the reversal decreases, the number goes up.

It doesn’t matter if the application is a servo motor system on piece of machinery or a gear increaser on a wind turbine.  The situation is the same.  It’s just more expensive when it’s a 30,000 pound reducer that’s 180 feet above the ground on a pole.    But the principles are all the same.

Keeping the machinery running is a tough task regardless of the field.  But monitoring the mechanical systems is key place to start.  Next generation gear boxes will likely include electronics to monitor the loading and condition of the gearbox to prevent catastrophic failures.

Next Page »