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Articles from 2005 In April


Wanted: Demanding Pneumatic Design Engineers

“What kind of performance or attribute is (most) important to you when designing compressed air powered equipment for your customers?” For engineers designing equipment for the packaging industry, a demanding high volume market segment, the number one answer was…

Ensuring uptime--chosen over speed, size, weight and even price.

If you design pneumatic systems and uptime is important to you, Norgren can improve your system’s uptime by minimizing downtime in both the air preparation and directional control valving areas.

The Right Start

One of the biggest causes of failure in pneumatic applications is inadequate air preparation. Proper air preparation involves filters, regulators, and lubricators - everything required to clean, condition, and control compressed air. These upstream functions are critical in an area where it just makes sense to sweat the details and demand more.


Heavy Duty Lubrication (e.g. large slow moving cylinders).  Shut-off valve, filter/reg, Oil-Fog lubricator, soft start/ dump valve, relief valve.

For air preparation, Norgren’s Excelon line is a complete air preparation system providing an integrated approach to a broad range of filtration, regulation and lubrication requirements. These direct-ported assemblies have a patented Quikclamp connection system, but can be used where both stand-alone units or modular assemblies are required. Addressing port diameters from ¼ to ¾-inch, the Excelon 72 and 74 units provide a flexible, modular approach with useful accessories such as pressure switches and manifold blocks. Designed for ease of maintenance, both systems include a quick release bayonet bowl, high visibility liquid level indicator, and easy to operate patented Quikdrain.

Check out more info on Norgren's Air Prep Solution Center.

Modular Plug-In Valves


Critical Pressure Control (e.g. precision regulation, fluidic systems, air gauging, process control).  Shut-off valve, general purpose filter, oil removal filter, drier, oil removal filter, precision regulator.

With a properly prepared pneumatic source, the next step to ensure uptime is choosing the proper control valves. Norgren’s VS Series provides a variety of combinations and configurations that can be built from one line of directional control valves. These are compact, selectable, solenoid operated valves that connect a manifold with no exposed wires and fit together in a plug-and-play manner.

With VS Series valves users do not have to replace the stack for modifications when the application requirements change. These expandable valves solve the problem of ratcheting up volume by providing a modular approach. Also, as system designs evolve, the modular approach provides the transition path to faster speeds and higher yield - and the means to differentiate products. The ability to transition quickly provides minimum machine downtime, which can be especially important if the reason to make the modification is increased capacity. This modularity and versatility breaks through barriers that have constrained previous valve systems.

Demand more uptime. Use Norgren’s Excelon Series Filter-Regulator-Lubricator units and VS Series valves to get it.

Check out more info on Norgren's Valve Solution Center.
 

Hot Topics. Real World Applications. Embedded Computing - It Is Easier Than You Think.

Connectivity is the name of the game in today’s most advanced electronic products. Hot application topics include Ethernet, USB, TCP/IP and ZigBee™ technology. The afternoon Advanced Connectivity Solutions seminar discusses all of these standards-based embedded applications. If you start from scratch, the newest standard for wireless networks, ZigBee, has over 12,000 pages of documentation and can take you days or even weeks to get up to speed. Microchip’s experts have condensed ZigBee and the other network standards documentation into concise course content and added systems’ demonstrations to simplify and reinforce the training process.

Find out how these networks operate, the reality of expected data rates, and how to get the most out of them. Using some of our newest products, we will show you how easy it is to add any of these to your next design. If you have an upcoming project that involves one or more of these networks, the payback will be immediate. And you can get started right away with the new PICDEM™ HPC Explorer demo board that is included in the registration price.

If you are just getting started using microcontrollers, our FREE morning Introductory Embedded Control Solutions seminar is for you. Hot components are a major concern in system design, whether it involves safety, functionality, or reliability. The Introductory Embedded Control Solutions seminar targets embedded control designers who are new to the PIC® microcontroller architecture or analog designers who need to learn how to integrate digital components into their applications. This session focuses on an application that uses temperature as the common theme and provides real world examples for getting up to speed on 8-bit microcontrollers. Starting with temperature limits, and progressing to displays, feedback for protection, and data logging with USB connectivity, the session goes from very simple to complex applications at a manageable pace and uses Microchip analog products that make temperature measurements easier.

The true value of these seminars is best judged by previous attendees, who said,

“Excellent product overview.”
“Wide range of solutions.”
“Inexpensive hardware.”
“Microchip has a good analog capability product line”
“The PIC microcontroller is variable, flexible and easy to migrate from chip to chip.”
“Many new Microchip products and upgrade path.” 
 
By attending one of these seminar sessions, you will appreciate how easy it is to get started in new applications with PIC microcontrollers and related analog products at either the beginner or advanced level. Both seminars will explain the software that Microchip provides and the different types of tools, including demo boards that are available. The flexibility and versatility of PIC microcontroller products simplify your job, and attending one of the 2005 seminars will make it even easier to get started.
 
For more information and to register go to microchip.com/seminars .

Electronics

POWER LINE FILTER

Reduce conducted noise

The CORCOM EMC series power line filters feature maximum current ratings ranging from 3 to 30A, which is reportedly higher than any similar catalog product. It is the most compact dual-stage CORCOM filter available from the company. It is suited to address the need for additional differential mode attenuation in the lower frequency range while maintaining high common mode performance. It can be used in applications where a high level of performance in a compact, cost-effective package is required. Tyco Electronicshttp://rbi.ims.ca/4390-605

HOLLOW SHAFT ENCODER

Company's largest bore

Suited for large motor feedback applications, the HS45 hollow shaft encoder accepts motor shafts up to 1.625 inches in diameter. It provides data for position and velocity control, and incorporates the precise feedback capabilities of an optical encoder with an easily mounted configuration to larger motors. It is engineered to provide an option for dual electrically isolated outputs. Should one set of outputs sustain electrical damage, a change of the connection enables users to get back up and running. BEI Industrial Encoder Divisionhttp://rbi.ims.ca/4390-606

MODULAR I/O PRODUCTS

256 digital inputs

Compatible with the company's SynqNet network, the family of modular SynqNet I/O products is comprised of a SynqNet Interface Device (SQID) and flexible analog and digital add-on boards that provide machine builders with a modular and cost-effective high-count I/O solution. It can be easily integrated to work with existing machine I/O and is also offered as a part of a developer kit solution for custom OEM solutions. The product family provides up to 256 digital inputs and outputs and 16 analog inputs and outputs per SQID. Motion Engineering Inc.http://rbi.ims.ca/4390-607

SENSOR

Detects fluorescent agents

The CZ-H52 UV sensor detects the presence of fluorescent agents used in a wide variety of products and packaging materials. It emits a UV light beam from the transmitter in the sensor head; the receiver picks up the visible light reflected by fluorescent materials. The product detects materials that are not only invisible to the naked eye, but cannot be detected by ordinary photoelectric sensors. According to the company, background colors and patterns do not affect sensor performance. Keyence Corp. of Americahttp://rbi.ims.ca/4390-608

ALTERNATOR-REGULATOR

Data received in single pass

The company has introduced a local interconnect network (LIN)-controlled alternator-regulator for next-generation vehicles. It is designed to optimize performance in intelligent automotive charging systems for increased efficiency and improved fuel economy. It offers integrated programmable load response control features, programmable field excitation of current or temperature, and regulator feedback of fault status. It can be addressed for compatibility with up to 15 other modules on the bus, and all data can be transmitted or received in a single pass. International Rectifierhttp://rbi.ims.ca/4390-609

LINEAR GUIDES

Available in various sizes

The company has released the two newest versions of the Advanced Measuring System now feature Digital Interface: the AMSD 3-A (for roller monorail) and 4-A (for ball monorail). By using a digital interface, digital signals are transferred directly from the read head without additional interpolation electronics. A special reference pulse for Fanuc controls is incorporated, as well as a service LED that indicates different modes of operation. The 3-A is available in roller guide sizes MR25, 35, 45, 55, and 65; the 4-A is available in ball guide sizes BM15, 20, 25, 30, 35, 40, and 45. Schneeberger Inc.http://rbi.ims.ca/4390-610

CO2 LASERS

All-metal design

The company's CO2 lasers are designed for use in a range of industrial processes, including cutting, welding, drilling, and marking. Like other traditional metal-cutting applications, CO2 last cutting requires the use of an assist gas, typically oxygen, to enhance cutting efficiency. The products reportedly feature the company's patented, all-metal tube. The all-metal, sealed tube design provides and maintains high gas purity, which is essential to achieve the long operating life required of the company's lasers, according to the company. Synardhttp://rbi.ims.ca/4390-611

PROCESSORS

Doubles performance

Featuring quad 1.5 GHz FreeScale MPC7448 PowerPC processors, the CHAMP-AV IV reportedly doubles the processor performance of its predecessor, the CHAMP-AV II, while reducing cost by almost one-third. The AltiVec -based DSP engine also features the company's QuadFlow architecture. It drives DSP applications with up to 48 GFLOPs of peak computational power, 256 Mbyte or 512 Mbyte DDR-250 SDRAM, and dual 100-MHz 64-bit PCI-X interfaces. Each processing node of the product is provided with a Gigabit Ethernet connection, according to the company. Curtiss-Wright Controls Embedded Computinghttp://rbi.ims.ca/4390-612

ABSOLUTE ENCODER

For miniature applications

Designed for applications where limited space is a factor, the MAS10-256-G is one of the smallest absolute rotary encoders in the industry. It measures 13 mm in diameter and 17.5 mm high. It is designed for a variety of applications, including medical devices, instrumentation, and robotics. It delivers 8 bits of absolute position information with a gray code, parallel output. It is capable of operating within a 0-60C range, and it can measure the rotary process as fast as 6,000 rpm. CUI Inc.http://rbi.ims.ca/4390-613

AUTOMATION SOFTWARE SUITE

Completes projects faster, cheaper

The FactoryFloor 4.1 industrial automation software suite is designed for use with the company's line of process automation controllers, typically combined with the company's SNAP Ethernet I/O and SNAP Serial I/O products. Using the software, users can develop powerful and diverse control programs; design human-machine interfaces; expand control systems' connectivity to enterprise databases; and complete control and data acquisition projects faster, cheaper, and more easily. It includes new security and auditing features for controlling and logging operator HMI use. Opto 22http://rbi.ims.ca/4390-614

FULL-BRICK CONVERTERS

Rated up to 50A

The PAF600F280 series is designed as a high-efficiency family of 600W full-brick dc-dc converters with a nominal input of 300V dc. They are suitable for systems using distributed high-voltage dc power architecture and for users designing custom off-line power supplies. It is rated up to 50A and is available with 12-, 24-, 28-, and 48V outputs. Features include over-current and over-voltage protection, remote sensing, output adjustment trim, remote on/off, current-sharing capability, a converter-good signal, and auxiliary voltage for housekeeping functions. Lambdahttp://rbi.ims.ca/4390-615

CAPTIVE LINEAR ACTUATOR

Durable design

The company's size 8 captive linear actuator is designed with an HIS patented integral anti-rotation mechanism. It is intended for applications in which external anti-rotation methods would be difficult or impossible to employ. It features engineering thermoplastics in the rotor drive nut and a stainless steel Acme lead screw. It is available in a range of resolutions ranging from 0.0015-0.04 mm per step, and it delivers thrusts up to 4.5 kg. Haydon Switch & Instrument Inc.http://rbi.ims.ca/4390-616

INTERFACE TERMINALS

Electronics upgraded

The electronics of the QTERM-G70 and QTERM-G75 rugged graphics operator interface terminals has been upgraded. New hardware features a 400 MHz Intel® XScale core platform with 8 Mbytes of Flash memory and 32 Mbytes RAM. They are designed for rugged industrial and vehicle environments, and they feature Ethernet-enabled color touch screens. The products use the company's object-based programming environment, named Qlarity. QSI Corp.http://rbi.ims.ca/4390-617

FERRORESONANT TRANSFORMERS

Require less filtering

The Ferroresonant transformers are designed to provide a stable power output (typically ±3 percent) for input voltages that vary as much as ±15 percent. The standard square wave output requires less filtering than linear transformers for dc applications. They are intended for use in battery chargers, medical equipment, inverter and UPS systems, line voltage stabilizers, industrial automation and machine tools, and other applications requiring a stable output with a high degree of isolation from line disturbances. Models are available for 50, 60, and 50/60 Hz, with output ratings from 50 VA to 5.0 kVA. Foster Transformerhttp://rbi.ims.ca/4390-618

INDUSTRIAL SWITCHES

Various combinations

The Series 04 range of sealed, illuminated switches are designed with a choice of possible combinations. These include square and round indicators and push buttons, rotary switches, emergency stops, and mushroom-headed push buttons. A compact, round indicator is also available for limited space applications, the company says. A selection of lens colors, engraving, and film inserts for legends and/or symbols is also available. EAO Switch Corp.http://rbi.ims.ca/4390-619

EXTENSION SYSTEMS

Delivers improved performance

Designed to provide enhanced power and performance, the company's expanded range of VME64 extension systems and products reportedly feature high pin count, improved signal shielding, higher power, and RTM support. The products are suitable for a variety of applications, including embedded controllers, medical imaging, and radar controllers. They maintain backward compatibility to existing 6U VME boards. Schroff Productshttp://rbi.ims.ca/4390-620

LEVER SWITCH

Prevents unintentional actuation

The 100 series K locking lever switch reportedly allows the toggle to be locked in any of the three positions to prevent unintentional actuation. They are suitable for rugged environments, and the panel-mounted switch is intended for wide application in instrumentation, test circuits, and industrial control equipment. It features plated brass and stainless steel construction, according to the company, and it has a minimum electrical and mechanical life of 40,000 cycles. E-Switchhttp://rbi.ims.ca/4390-621

SIGNAL CONDITIONERS

Various platforms available

The company's capacitive sensor signal conditioners are designed to provide excitation power for capacitive accelerometers, and to prepare their measurement signals for readout, recording, and data acquisition. A range of signal conditioner platforms are offered, including portable, benchtop, modular, and rack-mount styles. According to the company, all styles include per-channel null adjustment for zeroing in the dc offset voltage inherent to capacitive accelerometers, PCB Piezotronics Inc.http://rbi.ims.ca/4390-622

CONTROLLER/GATEWAY

Controls vehicle applications

The SAE J1939 controller/gateway uses the standardized application layer protocols CANopen and SAE J1939 to control the functions of special purpose applications on a vehicle and to enable the exchange of data between the applications and the vehicle's power train. It can simplify complex dashboards by giving operators clear and concise feedback from one central location. According to the company, it can also reduce the size of the cab's wiring harness. ifm efectorhttp://rbi.ims.ca/4390-623

ETHERNET SWITCHES

Rugged, intended for dc environments

The company's 10/100Base-T Ethernet switches reportedly accept any voltage between 10 and 30V dc with surge protection to 3,000V dc, making them suitable for any dc environment. The ADAM 6521 lets users interconnect four copper (RJ-45) and one fiber-optic (SC) networks, while the ADAM 6520 provides five RF-45 Ethernet ports. Applications include production lines, inventory systems, and conveyor control. CyberResearch Inc.http://rbi.ims.ca/4390-624

VRLA BATTERY

Small design

Designed to offer the same capacity as the company's previous model, the new low-profile, front terminal valve-regulated lead-acid battery features a 10 percent reduction in height. It measures 561 × 125 × 283 mm, and is suitable for such applications as power enclosures used in the wireless industry, and telecommunication and UPS applications. The product's container and cover are made from UL94 V-0 flame retardant ABS material. EnerSyshttp://rbi.ims.ca/4390-625

Machine Vision Finds the Goods

Introduction

Machine vision—traditionally thought of as a technology to spot defects or out-of-spec parts–has found a new use: pinpointing the location of materials in warehouses.

Open storage areas are present in almost every factory and warehouse, yet few methods exist to precisely determine and record material locations. Consequently, materials are misplaced, inventory accuracy suffers, and labor is wasted locating lost goods. By applying contemporary machine vision technology, Sky-Trax Inc., which develops technology to locate materials in warehouses, has developed a practical new solution to this old problem.

The Problem

Many current locator methods fall short of providing sufficient accuracy to locate a single pallet amidst thousands of others. For example, floor-painted aisles, overhead bar code placards, and sector markers can identify approximate location. Bar code labels or RFID transponders embedded in the concrete floor improve accuracy and automation readiness, but even these suffer from missing or imprecise location data due to sparse placement and the tags' vulnerability to physical damage and obscuration.

The Solution

Placing visual location markers overhead in the warehouse ceiling, and utilizing machine vision sensors to view upward and interpret the markers, has been a breakthrough concept. Marker panels are fabricated by Sky-Trax Inc. from sturdy but lightweight netting, and an array of printed position markers are attached at predetermined intervals. The netting with position markers is suspended above the area where items are to be stored or vehicles are to be tracked. Each position marker contains a coded symbol that uniquely identifies its place on the net which, after installation, is mapped to a corresponding floor location.

Embedded software running in commercial machine vision equipment performs the primary task of locating the coded symbol within the field of view, decoding it, and relaying the decoded data to a controller. The vision system, powered by DVT, determines the position marker's exact location and orientation within the field of view, and calculates its corresponding position in "real" space. All of this occurs within a few tens of milliseconds, yielding position update rates of several samples per second. Serving much like a global positioning system (GPS), the local positioning system (LPS) gives accurate position information that can be used to track stationary or moving objects. With this capability, a user can know in real time the exact location of equipment, materials, or individuals to an accuracy of plus-or-minus a few inches.

Sky-Trax incorporated a vision system on lift trucks to help operators locate stocks.

With the controller wirelessly receiving position data from a fleet of lift trucks, the motion and activity of each truck can be monitored. A graphic display on the controller console shows animated truck positions overlaid on a drawing of the warehouse floor plan. The lift truck operator views a GPS-like screen that shows his position in the warehouse, vehicle heading and velocity, and the location of other trucks. Coupled to a warehouse management system, the LPS reliably captures the location of each pickup or put-away with high accuracy and directs target pick and drop locations.

Conclusion

The Sky-Trax system with machine vision is in the beta-test process now. The company is also exploring other applications beyond forklift trucks.

Is Machine Vision Right for You?

As a design engineer at an OEM creates a machine for production, the first basic question is: "Do I want to inspect this part, or this product at all?"

Yes, inspection leads to higher quality, but there are instances where the cost of inspection and the product's quality requirements versus its value may not warrant inspection. Think about toothpicks: If there is a toothpick or two in the box of 500 that is not quite right, most people are not exactly worried about it.

But for many products, inspection is a real necessity. To this end, many OEMs build machine vision inspection into the systems that they sell to end users. Machine vision can add value to the whole system by increasing the productivity and accuracy of the manufacturing process and reducing costs for the system's user.

So how does a design engineer know when machine vision is right for their system? Although the first, basic machine vision systems were introduced in the 1970s, the industry is just revving up in terms of mainstream adoption. This may lead design engineers to wonder if it is right for their application, as well as trying to justify the cost versus the benefits of building machine vision inspection into a design.

Industries with highly complex products, such as semiconductors and electronics, have traditionally driven the market for machine vision due to their complexity and miniaturization. But today, all types of industries from automotive to pharmaceutical to paper processing are relying on machine vision to inspect products and increase the quality of the output. Industry experts predict that within the next 20 to 50 years, machine vision will become a universal factor across all industries, and that almost every product produced will be inspected by a machine vision system.

There are four main reasons for using machine vision:

  • Accuracy. Because the human eye has physical limits, machines have clear advantages in precision. Even when humans rely on a magnifying glass or microscope, machines are still more accurate because they can "see" and measure parts to a tolerance of thousandths of an inch.

  • Repeatability. Machines can conduct an inspection task over and over again in the exact same way without fatigue. In contrast, human inspectors tend to view an object slightly differently and may measure slightly differently each time, even if all the parts are exactly the same.

  • Speed. Machines can inspect parts faster. Especially when inspection takes place at high speed, such as on a production line, machines offer an advantage in productivity and efficiency.

  • Cost. Since machines are faster than humans, an automated inspector is worth several human inspectors. Machines also deliver higher uptime because they don't take breaks, don't get sick, and are just as efficient in the middle of the night.

Anatomy of a Machine Vision System

By integrating machine vision into its fluid-dispensing machines, Asymtek helped customers boost productivity in assembly and packaging operations. Such results earned Asymtek Intel's coveted Supplier Continuous Quality Improvement award.

Once an engineer determines the need for machine vision, the next challenge is to assemble the building blocks of the system. Among the essential components: lighting, part positioning, cameras, optics and control logic, as well as image acquisition hardware, processing software, and engineering services.

Chances are most vendors are not expert in all of these areas. So look for a supplier who not only knows its core competencies but has developed long-standing partnerships with other suppliers to provide other components needed for the system.

A good example of a company that has successfully incorporated machine vision inspection into its products is Asymtek (Carlsbad, CA). The firm has won many awards for the design of automated fluid dispensing systems used in the assembly and packaging of semiconductors, printed circuit boards, flat panel displays, electronic components, and medical/biotech products.

Two important applications for Asymtek's machine are underfill, which pulls the heat away from a semiconductor chip placed on a board, and encapsulation, a process that covers a chip and keeps the air off of it leading to less corrosion and greater structural integrity.

In these applications, the system must guide the fluid dispensing head to a precise target. Imagine guiding this process "blind"—that is, without seeing the surface that the fluid needs to be placed on, an almost impossible task. Machine vision makes this possible by letting the dispensing head "see" where the head needs to go, and then moving it to the exact position to dispense the fluid. The motion control setup, which positions the board on the conveyor, goes hand-in-hand with the machine vision system to make inspection as accurate and repeatable as possible.

Asymtek boosted the power and usability of its dispensing equipment by adopting a machine vision system as a standard feature on its Century, Millennium, and new Axiom 1010 dispensing platforms. The vision engine, produced by Coreco Imaging, provides an enhanced pattern recognition system. Among the key components: High-speed CCD cameras, Coreco's PCVision image processors, and Coreco's Sapera software to automatically correct work piece misalignment. For lighting, the system features an LED array with computer brightness control.

Together with Asymtek's software, the vision engine can take a series of measurements to find die edges and calculate the corner of the die. The vision engine provides several enhancements to Asymtek's pattern recognition systems as demonstrated by an increase in speed of up to 30 percent for detection of standard reference marks. Customers experience greater throughput and yield as a result of the faster image processing and more robust image analysis. These results earned Asymtek Intel's prestigious Supplier Continuous Quality Improvement (SCQI) award, its highest honor for its suppliers.

In simplest terms, the heart of a machine vision system consists of a camera, lighting source, image acquisition board, and processing software--all working hand in hand with the motion control system that positions the target part or object.


Web Resources
Coreco image acquisition and processing products
http://rbi.ims.ca/4408-511
Automated Imaging Association
http://rbi.ims.ca/4408-512
 

Sensing the Future

Name an end product—appliance, car, medical device, packaging machine—and you're likely to find one common component that shows up in ever increasing numbers: sensors.

In just the categories of proximity and photoelectric sensors, manufacturers in 2004 sold nearly $620 million worth of product in North America alone, Venture Development Corp. reports. Triple that figure to get an idea of global sales. For vision sensors, annual sales in North America have reached nearly $100 million with an annual growth rate of 45 percent.

But the rapid growth of sensors as a vital building block in countless applications hasn't occurred in a vacuum. It's a reflection of the technology's ability to adapt to the changing demands of product engineering.

Like other technology-driven markets, today's sensor industry strives to produce devices that not only cost less than their predecessors, but are smaller, offer more features, and are easier to use. Here's a look at some of the latest trends in sensor miniaturization, versatility, and usability—and the impact on product design.

The Smaller the Better

Microelectronic technologies that made it possible for computers to fit in shoulder bags and telephones in pockets also have led to sensors small enough to fit into a thimble.

Sensor designers can take advantage of advances in manufacturing, such as application-specific integrated circuits (ASICs), chip-on-board, and custom integrated circuits to design sensors that are very small yet sophisticated and highly integrated.

A huge benefit of these trends is that self-contained photoelectric sensors now squeeze into tiny areas, replacing the need for a separate sensing head connected by cables to a remote processing unit. Yet these miniscule sensors still provide the reliability, power, and durability that industrial settings demand.

For example, at a major U.S. corporation's telephone manufacturing plant in Ireland, a 1 inch long photoelectric sensor mounted below a conveyor detects the presence or absence of printed circuit boards moving along the line. If the sensor finds a gap between circuit boards, which can happen if there's a delay earlier in the assembly process, the sensor sends a signal that speeds up the line, keeping production on track.

Miniature sensors require seals different from the traditional weld seals. The overmolded housing on this sensor protects the inner components from dirt and moisture.

Sensor housings have changed, too. As sensors get smaller, traditional gaskets and glue for sealing no longer work. Instead, designers now rely on such techniques as overmolding and ultrasonic welding for the tight seals needed in rugged industrial applications.

For applications where photoelectric sensors are the most cost-effective choice, the industry trend now is to use the same housing style for different sensing modes to make it easier to change out the sensors for different applications. The installer can use the same mounting hardware for each device. On a manufacturing line, that pin-for-pin compatibility can save critical time.

"That's the beauty of a universal housing," emphasizes Joe Dolinsky, a product manager for Banner Engineering. "It's a familiar shape, so it's easy to install. There's less of a learning curve."

Ultrasonic sensors, used for measuring distance in manufacturing environments, are benefiting from the same advances as photoelectrics. Enhancements in modeling tools and manufacturing processes have led to ultrasonic transducers that fit into a smaller housing without compromising acoustic isolation and noise immunity. For example, on a printing machine, an ultrasonic transducer detects the level of ink in the tray that supplies ink to a roller. When the ink falls to a specific level, the sensor sends a signal that makes the ink tank refill the tray.

Ultrasonic sensors are often used with liquids. In this case, a tiny sensing head sends information to the nearby controller about the ink level in a commercial print press.

On the Rise: Vision Sensors

While photoelectric sensors will always have a place in automation, the versatility of vision sensors have helped make them the fastest growing segment of the sensor market.

"Vision sensors allow factory machine designers more flexibility and easier maintenance," explains Jeff Schmitz, Banner's corporate business manager for Vision Sensors. "Instead of lining up multiple individual photoelectric sensors to look for components and alignment, you can mount a single vision sensor and inspect for multiple features. And when you change the target—the object or product you're checking—there's no need to change the sensor."

For instance, in an auto assembly plant, a vision sensor is fit for automatically inspecting a bead of adhesive that a robot applies to the border of a door panel. The sensor can check that the bead is the right width and has no breaks in it— and that the robot didn't apply adhesive elsewhere on the panel.

For the majority of applications that require a vision sensor instead of a photoelectric, standalone vision sensors are taking the place of older multicomponent systems, which required expertise to set up. "In addition to reliable performance, the market is demanding ease of use," Schmitz says. "For example, all our vision products have the same graphical user interface and a guided four-step setup."

Another ease-of-use feature is the sensor's ability to learn what features to check for—just by seeing an example of a quality product. "Teach capability lets operators on the line show the sensor what a good product looks like," Schmitz explains. "The sensor automatically sets the parameters. That's especially important when lines continually get different products—like a new date code. The sensor learns the new code without the operator having to stop the sensor or use a PC."

Teaching capability—called simply "teach" in the sensor industry—applies to other sensor types as well. It is increasingly common in microprocessor-based sensors, such as Banner's WORLD-BEAM® QS18 Expert™ photoelectric and ultrasonic sensors and in the WORLD-BEAM® QS30 laser-based models.

The PresencePlus P4 GEO sensor--one of several vision sensors from Banner Engineering--can find the target on an object regardless of how the object is oriented.

Teach lets the operator show the good product to the sensor when away from the line, which is an asset when accessibility is a problem, either because the manufacturing environment is harsh or because the sensor is buried deep in the machinery.

From the user's perspective, advances in sensor technology are making different sensor types behave more like each other. Vision technology is less intimidating than it used to be. Photoelectric sensors can do more, and ultrasonics are more reliable. And because sensors are smaller and less costly, manufacturers can use more of them—in applications that were once off-limits because of size or expense.

Looking to the future, the push now is to take advantage of greater flexibility and affordability to fit sensors into more applications. Venture Development Corp. projects the greatest growth in the pharmaceutical, food, and beverage industries. The forecasting company also predicts strong growth in sensors that use fiber optics, especially infrared sensors. Meanwhile, applications of vision sensors promise to keep increasing at phenomenal, double-digit rates.

Web Resources
To learn more about sensors in automation:
Sensor theory
http://rbi.ims.ca/4408-500
Examples of sensor applications
http://rbi.ims.ca/4408-501
 

Meter Serves as a Signal Source

Follow the Script: The script language in the Keithley Series 2600 SourceMeter family lets engineers quickly automate tests that require simultaneously sourcing and measuring currents and voltages.

Few things irk engineers more than having to make dozens or hundreds of careful measurements of device characteristics while simultaneously varying a current or voltage. This tedious process takes considerable time and one error can undo test results. The Series 2600 SourceMeter instruments from Keithley Instruments combine a voltage and current meter with a voltage and current source that operate independently or together. The capability to operate the source unit in synchronization with the measure unit lets the instrument automate many repetitive measurement tasks. Those tasks can occur either in a stand-alone mode controlled solely by Series 2600 instruments or under control of a host PC.

The source-measure capabilities provided by the Series 2600 instruments serve engineers who must make current and voltage measurements on devices such as transistors, displays, display-driver circuits, radio-frequency amplifiers, disk-drive read-write heads, individual passive components, and so on. As a stand-alone instrument, the measurement portion of the Series 2600 SourceMeter can acquire 12,600 readings/sec. Each reading includes a simultaneous current and voltage measurement. When combined with the current-voltage source, the instrument operates at 4,750 source-measure cycles/sec. A new type of ranging control lets the output of the source-measure unit settle quickly, thus increasing test speeds over those available in other instruments.

Each member of the Series 2600 family includes a Test Script Processor (TSP) that lets it function as a stand-alone instrument system. Keithley's Test Script Builder software, which operates within an instrument, provides a simple graphical user interface that lets engineers and technicians develop, modify, and debug high-speed test-and-measurements programs, or scripts. A BASIC-like language simplifies writing these scripts. Easy-to-read commands such as smua.reset() and smua.measure.rangei=1.0 establish a current-measurement range, for example.

The flexible TSP "language" includes the following capabilities:

  • Instrument command queuing

  • Modular subroutines with passable parameters

  • Pass/fail and limit testing

  • Math operations

Keithley Instruments http://rbi.ims.ca/4390-576

In the Marketplace

Vision Sensor

Delivers high-speed error-proofing and inspections

Able to accurately sense and evaluate more than 10,000 objects per minute, the P4 EDGE is fit for validating the height and width of parts, location of labels, or detecting the edge of materials such as plastic or paper on a Web operation. Other features also make it easy to deploy and be operational quickly. For applications where product lines are constantly being changed, a remote TEACH feature allows the sensor to learn new elements it will need to inspect for without connecting to a PC or shutting down the line. It can interface to machines and factory networks via its built-in 10/100 Ethernet connection, RS-232, or discrete input/outputs. Included mounting brackets facilitate easy location of the P4 EDGE sensors on machines or conveyors. The units feature three bicolor LED indicators to clearly show unit status during setup and operation. Banner Engineeringhttp://rbi.ims.ca/4408-576

Pressure Sensor Module

Low-power, low voltage

Intended for consumer, medical, and general application for barometric pressure/altitude, the MS5534B is an SMD-hybrid device including a piezo-resistive pressure sensor and an ADC-interface IC. It provides a 16-bit data word from a pressure- and temperature-dependent voltage. Additionally the module contains six readable coefficients for a highly accurate software calibration of the sensor. The MS5534B comes with automatic power down (on/off) switching, and a three-wire interface for all communications with a microcontroller. Sensor packaging options are plastic or metal cap. Compared to the previous generation, the temperature range has been improved (-40 to +125C) as well as the pressure range (measurement down to vacuum). Other improvements have been made with ESD sensitivity, current consumption, and converter accuracy. Servoflo Corp.http://rbi.ims.ca/4408-577

Angular Position Sensor

Intrinsically linear

The new "ILAPS" non-contact angular position sensor provides intrinsically linear output over 120-degree maximum travel without the need for electrical compensation. According to the company, it is fit for pedal, throttle, and valve position sensing. Complete technical information and a free product sample are available upon request. Cherry Electrical Productshttp://rbi.ims.ca/4408-578

Two-Phase Hybrid Stepper

Miniature in size

The 208 is reportedly the smallest two-phase hybrid stepper to date. This 1.8-degree bipolar NEMA 8 miniature step motor is intended for applications where space is limited. The motor measures 0.79-inch square and is available in two stack sizes: 1.30 and 1.69 inches in length. Although it weighs a mere 0.13 lbs, it is still capable of up to 4.2 oz-inch of holding torque depending on stack size. The 208 is also available with a standard rear shaft extension. Suitable applications are medical, communications, semiconductor, and robotics. Lin Engineeringhttp://rbi.ims.ca/4408-579

Analog Sensors

With non-traditional housings

Non-traditional housings styles are exemplied on the Bi20R-Q14-LU ring style and the Wi70-M18-LIU5 probe style sensors. These analog sensors are specified with a repeatability of less than 0.5 percent and linearity of 3 percent. The Bi20R-Q14-LU is a three-wire, 15-30V dc sensor with a 0-10V output in a ring style housing with a 20 mm diameter hole. This sensor is fit for the identification and sorting of small parts (such as screws) as the sensor generates a different output signal for each size part. Position control applications can be resolved with the Bi20R-Q14-LU by means of a cone-shaped target as well as the detection or measurement of tools (such as drill bits). The Wi70-M18-LIU5 is a four-wire, 15-30V dc analog sensor with either a 0-10V or 4-20 mA output. Housed in a standard 18 mm barrel, the 75 mm probe has a linear operating distance of 70 mm. This probe style sensor can detect all metals and can be used in a variety of areas, such as the positioning of metal parts as they move over the length of the probe. TURCKhttp://rbi.ims.ca/4408-580

Low-Cost Pressure Sensor Module

For pressures up to 0.5 psi

A small six-pin pressure sensor, the FPM-005PG is designed for consumer, medical, and general applications for pressures up to 0.5 psi. Users include HVAC, breathalyzer, and breath detection (apnea, oxygen conservers). Servoflo Corp.http://rbi.ims.ca/4408-581

Hall-Effect Snap Switch

Comes with sensing fuctions

The D4 Series snap-action switch with Hall-effect technology is tested to 10 million operations and reportedly goes where no switch has gone before. Technical information and a free product sample are available upon request. Cherry Electrical Productshttp://rbi.ims.ca/4408-582

Multi-Segment Type 4 Safety Light Curtain

Allows for quick setup and changeover for different job requirements

The MiniSafe Flexible MSF4700 family of safety light curtains are engineered to withstand high shock and vibration environments typical of punch presses and other heavy industrial machinery. Their multi-segmented design allows them to protect up to four different openings by connecting up to four 35 × 50 mm housings in sequence. Protected heights from 150 to 1,800 mm and resolutions of 14 mm, 20 mm, and 30 mm are also available, with any combination thereof being possible. This ability to customize height and resolution for each light curtain segment allows for a true custom fit to the specific machine. In addition, remote fixed-blanking allows for quick setup and changeover for different jobs. The controller is available in a 35 mm DIN IP20 enclosure with 24V dc solid-state safety outputs. It is also available in a 14 gauge steel IP65 lockable enclosure with a choice of solid state or dry contact outputs (mechanical relays). Scientific Technologies Inc.http://rbi.ims.ca/4408-583

Optical Proximity Sensor

Long-distance reflective switch can detect objects up to 24 inches away

The OPB720 Series sensor is packaged in a miniature plastic housing that measures just 1.1 (27.9 mm) × 0.68 (17.3 mm) × 0.033 (8.4 mm) inches. It is suitable for most industrial machines, material handling equipment, and packaging equipment, as well as high-volume commercial applications. It consists of an infrared LED and a photodetector, and objects as small as 0.08 inches (2 mm) can be recognized by the sensor at distances up to 8 inches (203 mm). The OPB720 sensor features collector dc current of 50 mA, with power dissipation at 300 mW. The sensor can switch from high level with no reflection target to low level with reflection. Designed to be compatible with most PLCs, the OPB720 sensor features open collector output, with an operating power requirement of 30V. OPTEK Technologyhttp://rbi.ims.ca/4408-584

LED Outlook Brightens

LED Outlook Brightens

Nick Holonyak has predicted nothing short of a transformation in lighting ever since the mid-60s, shortly after he discovered how to get semiconductors to emit light. These days, he still gushes when he's asked about the future of LEDs, which he invented in 1962.

"People have never before had the choices in color variations, where they could do so many things with size, form, and layout to put any color of light anywhere, and do all that more efficiently so they're saving energy and reducing their costs," says Holonyak, now a professor at the University of Illinois in Champaign.

This slow transformation is picking up steam as LEDs improve brightness and come down in price. The emergence of white LEDs is helping the technology displace incandescent bulbs, a shift that's also being driven by pricing declines and higher light output.

Companies such as Color Kinetics Inc. of Boston are working with architects, theater set designers, and many others who are making Holonyak's dream come true. Color Kinetics' hardware illuminates a broad array of building interiors and exteriors, ranging from the Hard Rock Hotel in Las Vegas to Philadelphia's Ben Franklin Bridge to the Overture Center for Arts in Madison, WI. The Rock Styles exhibit in New York's Museum of Modern Art and the Boston Ballet's Nutcracker presentation also rely on solid-state lighting.

Various color LEDs can be placed in hidden locations, letting architects and set designers change moods and appearances easily. "Places that never dreamed of color changing now routinely ask it, in theaters, on bridges, and in government buildings," says Ihor Lys, co-founder and chief technology officer of Color Kinetics.

Simplified color variations are only one reason growth is surging. "They're smaller, have 10 times better life, better performance, and use less energy than incandescents," Holonyak says. They also meet new ecological regulations that ban mercury and lead.

Volume consumer applications go far beyond the simple alarm clock LEDs used for decades. Now, they're being used for backlights in LCD TVs, replacing cold cathode fluorescents. Sony and Samsung are starting to use red, green, and blue LEDs to improve TV color quality and increase brightness. "Using red, green, and blue arrays gives you stunning color with a wider gamut of colors," says Robert Steele, senior analyst at Strategies Unlimited of Mountain View, CA.

While brightness and low power consumption drive many designers, the small size of LEDS is also a factor in their growth. Mitsubishi Digital Electronics America unveiled the PocketProjector, a 14-ounce, handheld unit that uses LEDs to enlarge images stored in computers, cameras or even handheld games. Red, green, and blue LEDs display an SVGA image that can measure 40 inches when the display surface is less than a yard away.

Colorful: Colors and moods can be changed easily with LED lighting in buildings like Wisconsin's Overture Center for Arts.

Technical advances

The rapid increase in usage is sparking an increase in R&D around the globe. White LEDs are only a few years old, but they're already reaching brightness and pricing levels needed by the demanding automotive industry. Holonyak notes that over time, white LEDs will be made with simpler processes, bringing pricing down even further.

A recent example of current technical progress comes from Lumileds Lighting of San Jose, CA, a joint venture between Agilent Technologies and Philips Lighting. White versions of its recently upgraded Luxeon technology now emit up to 65 lumens at only 350 mA, or about 60 lumens per watt. That's roughly four times the output per watt of a conventional incandescent bulb.

Increasing brightness is critical for both total effect and for reducing the number of LEDs needed to light a given area. "We've always used the brightest LEDs possible; we want the most efficient lumens per watt we can get," Lys says. That's especially important with white lights, "which pretty much always run at full power," he adds.

Shrunk: LEDs let Mitsubishi reduce a projection display system to handheld size.

The Luxeon line also has a junction temperature of 185C, 50 degrees higher than the previous generation. That is seen by some as a major breakthrough. "There's almost been a law of physics that says you couldn't exceed 125C," Steele says.

It should help white LEDs crack into automotive applications, which have more stringent ruggedness and reliability requirements than many fields. "This eliminates any concerns about temperature," said Jeff Raggio, automotive business development manager at Lumileds.

Another benefit of improvements like these is that when brighter LEDs can be run at full power, fewer are needed. Market watchers generally agree that high brightness LEDs will make up the bulk of future growth. Strategies Unlimited predicts that segment will nearly double last year's $3.7 billion by 2009, when revenues could hit $7.2 billion.

Uses: Mobile products like the low power and output of high brightness LEDs, which are also popular in cars and signs.

In large applications, the shift to increasingly brighter lights can mean a reduction in overall power and heat budgets. Using fewer high-efficiency LEDs reduces the need for fans, which are noisy and reduce reliability. "We do whatever we can with passive cooling, using thermally conductive epoxies and all sorts of things to get heat out," Lys comments.

Improvements with LEDs sometimes take dramatic leaps, but for the most part, they follow a familiar path, advancing steadily along a course similar to that of conventional semiconductors. "Globally, there's a road map that foresees output of 150 lumens per watt by 2012," says Nadarajah Narendra, solid state research director at the Lighting Research Council at Rensselaer Polytechnic Institute in Troy, NY.

The research endeavors are international, as are efforts to build a manufacturing base for a technology with huge growth potential.

Strong Growth: High brightness LEDs are the fastest growing segment of the industry, nearly doubling by 2009.

"China is very interested at the highest levels of government," Steele says. LEDS are seen as a partial solution for China's energy problems, he explained.

"Korea, Taiwan, and China are all gearing up LED manufacturing operations," Narendra adds.

Chipmakers are also helping enable the transition. Color Kinetics was recently able to reduce the number of components in a system by using Microchip controllers that add a DSP core to the main processor. "Our older line had about 150 parts. We're able to get that down to 100 and reduce costs a fair amount, since some of those components are pricey," Lys says.

Online Conference

Online Conference

On May 17, Design News will produce E2E on Automotive technology, a special online conference with engineers on Automotive's toughest design challenges. On June 15, Design News and EDN will jointly produce E2E on Electronics/Test and Measurement, a special online technical conference on current engineering issues and challenges in electronics. The editors of the two magazines are developing the topics and identifying speakers. Among the general topics: wireless technology, sensors, power and heat management, and buses and boards. Don't wait. Register at www.designnews.com/E2E.