C.G. Masi, Control Engineering
Articles
Everything needs calibration
Tutorial: When it comes to extreme high-accuracy motion control, such as marking the fiducials on precise linear encoders used to make integrated circuits with critical dimensions at the few tens of nanometers level, temperature variations are often considered the most serious issue. These encoders have to be made with picometer precision.
Microprocessor advances translate into more CNC machine capability
It is a fact of life that the needs of general-purpose-computing drive microprocessor trends. Simple semiconductor-fabrication economics makes mass-marketable designs very inexpensive, while making designs aimed at smaller market segments, such as CNC, cost prohibitive. “Advances in technology help all technologies in a general way,” says Paul Nickelsberg, president and chief techni...
Hybrid approach to system design
The age-old debate among system designers and their managers is whether to use top-down or bottom-up design techniques. Experience shows that a hybrid approach works best. Top down To use the top-down method, the designer starts with the big picture and works down to the details. The top level looks generally at what the prospective user wants the system to do and the major specifications.
Picking a Controller Technology
Embedded control systems vary from temporary data acquisition and control systems running experiments to “brains” for standard mass-market products. Embedded control systems also range in complexity from telecommunications switching systems to alarm clocks. Different applications have different requirements, with several form factors available to meet them.
Arc flash blowout
Arc flash is quite different from electric shock. When a person gets an electric shock, effects arise from the passage of electric current through sensitive tissues, mostly nerves. Arc flash occurs when electric current passes through air. Arcs generally begin when conductors in contact and carrying high current are pulled apart.
Industrial Machining Embraces Nano Positioning
Where several ten-thousandths of an inch was once considered to be high precision, some applications now require the ability to reach sub-micron levels.
New Technology Changes the RTOS Game
Not long ago, building a digital control system for a real-time application was relatively simple. You started with whatever real-time operating system (RTOS) you were most enamored with, selected a microcontroller that was 1) supported by that RTOS, and 2) had price, performance, I/O features, and memory that met your application needs.
GM’s Net Keeps Production Moving
When designing its global command and control network, General Motors executives' first priority was supporting production operations.
Smart Cameras Resolve Control Issues
Image analysis for machine vision applications is essentially an exercise in data reduction. The raw data stream is a torrent. A single black and white image from a 1,000 pixel x 1,000 pixel image sensor reporting 16 gray levels contains roughly 500 kB of data. At a standard frame rate of 30 f/s, that amounts to 15 MB/s.
How Encoders Make Automated Motion Safe
At its core, automation is defined by control loops, but automated machine safety is more aptly described as an arrow. And that arrow’s sharp point is often an encoder that makes it possible for the control system to know where it is and how fast it’s moving. With that knowledge, the system can not only avoid trouble, but act appropriately when circumstances bring trouble to its door.
Modeling in motion
The convergence of mechanical, electrical, and software engineering is changing the face of motion control design and development. This tutorial shows how.
Single Board Computers for Control Applications
Haydn Povey, senior product manager at embedded processor designer ARM, points out: “People are moving from PLCs to high-end microcontrollers as their control algorithms become more complex.” According to David Pursley, applications engineer for Kontron, changes in the engineering community also fuel a trend away from traditional control technology: “In the last two or three y...
NIST…it’s not just for calibration
The National Institute of Standards and Technology (NIST) is a U.S. federal agency under the Department of Commerce. Founded in 1901 as the National Bureau of Standards (NBS), the agency was the first physical science research laboratory of the federal government. It became the National Institute of Standards and Technology in 1988 to better reflect the expanded role technology development supp...
Wireless Control Sets Automated Vehicles Free
As pointed out in the Wireless Control Supplement to the August 2007 Control Engineering, one of the main motivations for incorporating wireless communications into automated control systems is to free moving system components from tethers. Using electrical cables to carry control signals to and from moving system components hobbles them.
The Culinary Art of Mechatronics
Tutorial: If you’re a Food Channel fan, as I am, you probably have heard Alton Brown talking about hardware and software as ingredients in culinary projects. Today, we’re going to talk about some of the hardware and software ingredients that go into mechatronic projects. For Alton Brown, software includes eggs, milk, water—all the “wet” stuff that goes into food.
Building block diagrams
Back to Basics: The term “block diagram” refers to a type of diagram used by engineers to visualize system interactions at a high level. Block-diagram visualization allows system engineers to separate needs analysis from system design, and start system-level design before finishing component-level designs.
Potential Power Picks
Choosing power options for an embedded system is a bit like ordering from a Chinese menu: “One from column A, one from column B, and one from column C.” Instead of being labeled “appetizer,” “soup,” and “main course,” the columns are labeled “primary,” “recharge,” and “backup.
Medium voltage drives
Back to Basics: Medium voltage drives are those putting out 600 V or more. Motor/drive sets operating at “medium” voltages up to 24,000 V have been built and operated. Generally, such drives are variable speed ac drives intended for high-power applications. They typically achieve power regulation by pulse-width modulation to match drive power with mechanical load requirements at the desired speed.
On-Machine Controls
Installing machine controls on the actual machine is not a new idea. Mechanical control systems, of course, were perforce installed right on the machines they controlled. They had to be, because controls were operated through mechanical linkages. Manual controls for electrically powered machinery continued to be installed on industrial machines to give human operators easy access.
Signal Conditioning for PC-Based Control
When you’re using a standard control solution such as a programmable automation controller (PAC), says Bob Nelson, business manager for controller I/O and software at Siemens, “the manufacturer takes care of the inner-workings of that controller, so the user doesn’t have to worry about them.
Connecting the Plant and the Enterprise: Taking Automation to the Next Level
Mitsubishi Electric Corporation (MELCO) recently hosted journalists from all over Europe and this reporter from North America to exclusive, full-access tours of several highly automated Japanese industrial plants. This article takes a look at the state-of-the-art automation we found and how Japanese industrial-automation engineers are working to link the shop-floor with enterprise-level networks.
Not Your Grandfather’s Conveyor Line!
As I sit, staring out of this airport window at a baggage handler unloading the belly of a not-so-jumbo jet, I’m struck by how woefully behind the times that baggage handling system really is. We have a human manually picking packages off a mobile conveyor belt that he earlier towed up to the jet with a little riding tractor.
Safety Improves Robot Efficiency
A spirit of innovation has helped Dürr Paint Systems become one of the leading suppliers of paint finish solutions. Its Ecopaint robot, which is currently used in more than 2,000 applications, is a primary example. Capable of high-quality paint finishes on everything from automobile manufacturing, aerospace and commercial vehicle industries, the Ecopaint produces a finished film thickness...
Getting Control of Electric Power
There is a temptation for control engineers to simply assume that facilities managers will magically provide electric power in sufficient quantity and of sufficient quality to feed the automated systems they create. These systems, however, have appetites large enough to disrupt finely balanced electric distribution systems, degrading power quality.
Analog Encoders Reduce Pre-alignment Time
How do you double semiconductor wafer throughput, decrease wafer pre-alignment time fivefold (to 600 ms), and improve in positional repeatability fivefold (to 5 nm), while at the same time reducing cost and increasing reliability? The competitive nature of the semiconductor industry places increasing importance on performance characteristics and integration ease for motion controllers used in t...
All My Best Ideas are Stolen
Physicist and star of educational TV during the 1950s and 1960s, Dan Q. Posin was fond of quoting Isaac Newton: “If I have seen further it is by standing on ye shoulders of giants.” Designing control systems may not be on the same level as Newton’s contributions, but “standing on the shoulders of giants”—that is, learning from others’ experience—i...
Fuzzy Neural Control Systems — Explained
While engineers in the controls community have been busy migrating from traditional electromechanical and analog electronic control technologies to digital mechatronic control systems incorporating computerized analysis and decision-making algorithms, novel computer technologies have appeared on the horizon that may change things even more.
Wireless Keeps Machines Coordinated
Wireless integration of control systems has been around for a long, long time. Wireless remote control of aircraft and marine vessels—essentially the technology used by RC (radio controlled) modelers today—was developed before World War II. Because the barriers to entry have been lowered so dramatically, wireless control has become competitive with wired control for most applications.
Preparing for Networked Safety
Gone are the days when they used to think about a hardwired system as being the only method, says David Arens, safety expert at Bosch Rexroth and member of the the American Society of Safety Engineers. “A safe system is simply defined as one that if it fails, it fails in a way that is going to protect the people and the machinery and the plant,” explains Brian Oulton, marketing mana...
Preferred Suppliers Speed Integration
Serving customers in industries as varied as automotive, medical device and nuclear power, automated assembly machine builder, Wright Industries, a Doerfer Company, builds a variety of custom-designed automated assembly equipment—from complete turnkey systems to single station machines. Such machine builders must become experts on automation technologies from multiple suppliers, while als...
High-resolution monitoring speeds bearing press-fitting
A transmission, transfer case or differential may contain four to six bearings that are press fit into place on assembly lines turning out as many as 3,000 transmissions a day, so the problem of automatically finding the exact end point when the part is seated properly is especially widespread in automotive powertrain assembly.
Teamwork for System Development
To get the most out of your relationship with your system integrator, whether a third-party integrator or a team within your organization, you first must prepare carefully, then communicate frequently—but not too frequently. Preparation starts with knowing your goals, and that’s not as easy as it sounds.
A Rainforest Grows in Cleveland
Behind the scenes, a lot of control engineering goes into creating and maintaining a tropical rainforest near Lake Erie, just 40 miles from the Canadian border. It is a feat accomplished by Cleveland (Ohio) Metroparks, a recreational authority that provides an “emerald necklace” of woodlands, golf courses, hiking trails, and other attractions surrounding this Midwest city—know...
Visualizing temperature
Just as thermal imaging is becoming white hot for predictive equipment maintenance, industrial engineers are becoming increasingly aware that it makes an excellent primary sensor to keep control systems on track. Thermal imaging, or thermography, maps the surface temperature of an object by means of the infrared (IR) radiation it emits.
Machine Vision: Not Just for Metrology Anymore
To many manufacturing engineers, machine vision (MV) on the factory floor is just a metrology tool. They’ve gotten used to applying machine vision to speed up inspection and gauging applications for quality control, especially for 100% inspection situations. What they haven’t come to grips with, yet, is something that electronic printed-circuit assembly engineers embraced years ago:...