Engineering News

By Design News Staff -- Design News, March 27, 1995

Exotic materials enter the marketplace

Newton, MA-- Advanced materials have helped push the envelope of such technologies as spacecraft, jet engines, computers, and telecommunications. However, most of these materials generally fulfill their complete potential only when new design methods are applied to new products. As a result, many of these innovative materials wait "on the shelf" until new markets develop.

Instead of taking a "wait and see" attitude, engineers might try applying such materials to incrementally improve existing products. Such actions offer an attractive way to use an existing market to build demand for a product-without exploiting the material to its fullest extent.

Some enterprising entrepreneurs have taken the latter route to introduce a variety of exciting new materials to the marketplace. Among them: a metal foil that promises considerably improved performance for catalytic converters; a polymer that can be easily remolded or reshaped to conform to changing needs; and minute crystalline structures that can give more conventional materials significantly improved properties.

Shape Memory Polymer. Imagine a child's bicycle helmet that can be remolded at home so that you can adjust its size as the child grows. Or how about an eating utensil that can be reshaped by the physically handicapped to meet each user's special needs. Such products can be produced, thanks to a Shape Memory Polymer (SMP) developed by Mitsubishi Heavy Industries Ltd., Tokyo, Japan.

The patented "smart" polyurethane is easy to process, according to its maker. Under certain conditions, which can be customized, SMP can transform its shape and hardness, then return to its original state, if so desired. Shaping takes place when the material is heated, while quick cooling enables it to retain its shape. If reheated, the material "remembers" its original shape and returns to it.

The material comes in pellet, solution, or liquid form for easy compounding. Conventional equipment can be used to injection-mold, extrude, coat, or cast SMP. Semi-finished products are available, including foam and microbeads. The material also recently passed critical biocompatibility lab tests for use in medical devices.

A new clad metal materials synthesis process, developed by Texas Instruments' Metallurgical Materials Div., cuts the cost of advanced stainless-steel catalytic converter materials "to a level competitive with existing ceramic technology." At least that's the contention of Richard G. Delagi, a fellow in TI's Materials & Controls Group, Attleboro, MA.

The resulting materials, says Delagi, provide two major benefits over ceramic catalyst substrates. Their greater strength and resistance to thermal shock lengthen catalyst life. And they permit auto engineers to locate the catalysts closer to the engine exhaust manifold, where they will reach operating temperature more quickly. Thus, they "light off" (reach operating temperatures) faster, cutting emissions by as much as 40%, Delagi explains.

TI's synthesis process lowers the high fabrication costs inherent in conventionally produced catalytic-converter metals. The problem: High alumium content in ferritic stainless steels makes them hard and brittle. As a result, they are difficult to roll and fabricate into finished catalyst substrates-without high material losses and expense.

The TI process starts with a clad metal composed of steel clad on both sides with aluminum. This clad material rolls easily into the complex shapes required by catalytic-converter manufacturers. The alloy is formed from the clad precursor by diffusion heat treatments after the final catalyst monolith is formed.

Despite the higher cost of catalyst foil produced by conventional ingot metallurgy, various European car makers have changed to metal substrates because of their weight- and emission-cutting advantages. At least one U.S. manufacturer included metal catalysts on 1994 models. With the less expensive TI process, more manufacturers are certain to jump on the bandwagon, according to Dan Conroy, vice president of the Materials and Controls Group. The metal substrates are currently being produced by Emitec GmbH, Cologne, Germany, a joint venture of British-based GKN and Germany's Siemens. Expect to see them debut on 1996 model cars.

Nanocrystals. Nanocrystal materials are individual, discrete particles of conventional materials-ceramics and pure metals-with an average particle size that ranges from 10 to 100 nanometers. Because of the dramatic size reduction, the surface area to volume ratio of the material is greatly increased. This gives the material greater reactive potential, higher surface energy, some unique interface characteristics, and improved atomic diffusion qualities.

Thanks to a group of prominent Russian scientists, engineers can obtain quantities of these nanocrystalline structures for review from PPP Consulting, Morrison, CO. The Russian-developed processes used to produce a variety of the nanocrystals include: evaporative-condensation and super-high-frequency plasma chemical treatment. An in situ process also can be used to produce several nanocrystalline structured materials, such as the company's Danaloy DSC dispersion-strengthened copper alloy.

Under the evaporative-condensation method, pure metals are vaporized at temperatures as high as several thousand degrees centigrade, then condensed to form the nanocrystal materials. Because they are generally highly reactive, these particles are then passivated in order to render them more suitable for handling. In the super-high-frequency plasma chemical process, various chemicals and gases are reacted in low-temperature plasma to produce the extremely small oxide and nitride nanocrystals, again in discrete particle form.

Enhanced materials. "Use of nanocrystal materials often transforms once-conventional materials into materials with significantly improved properties," says Joseph H. Dabaghian Jr., who heads PPP Consulting. "For example, the improved grain structure can make steel casting materials tougher and more resistant to wear. Likewise, properties of certain ceramics may be enhanced, making them ideal for heat-tolerant engine parts and electromagnetic components, as well as fuel cells."

Researchers at the National Institute of Standards and Technology and the University of Michigan have purchased some of the materials for evaluation. Dr. Ziv Livne, an Israeli "guest scientist" at NIST's metallurgy facility in Gaithersburg, MD, reports they are researching the consolidation of such nanostructure materials. He notes that the Russian-produced materials are the lowest in density of any they have worked with to date. Bryan Suits, who heads the University of Michigan's Department of Physics, says that his nanocrystals are "still in the box." He hopes to incorporate some of the aluminum particles in the university's study of nanophase materials using nuclear magnetic resonance.

"Nanocrystal materials can be combined with other substances to create new classes of bulk materials, including composites and dispersion-strengthened materials," Dabaghian adds. "Similarly, scientists can use the materials to create tailor-made materials, products, or processes for specific applications that far outperform conventional materials."

What this means to you

• Don't overlook advanced materials as a way to enter new markets.

• Many advanced materials can be tailored to meet innovative or special product or process needs.

• Even limited use of a new material may permit companies to beat the competition in the design of a new or improved product.

--Gary Chamberlain, Senior Editor

Solids modeling streamlines development

Melbourne, Australia- When the So-Rite engineering firm was asked to create a femoral implant from an architectural-style drawing, it declined. Instead, So-Rite used Hewlett-Packard's ME30 solids modeling software to create a 3-D model from scratch. The software let engineers analyze and alter 3-D models quickly and easily, to obtain the optimum features dictated by an orthopedic surgeon.

So-Rite produced a computer model of the exact prosthesis required, and then created the NC programs needed to do the machining. Engineers at the company wrote a post-processing program in order to go from the solids model to the NC codes. This lead to tooling production and ultimately to the manufacture of the stainless-steel femoral implants.

"When you've created a computer model, you can't simply put it on a machine and produce it," says Neale Jackson, managing director at the company. "You have to work out how to "hold' the model and design the fixtures and jigs to do so.

"We can use the 3-D models to anticipate problems and solve them before the production process begins," explains Jackson. "The software gives us confidence that the design data generated for CNC machine tools is accurate."

System filters water for backpackers

Seattle, WA-- Mountain Safety Research (MSR) has developed a portable filter system to provide backpackers and other outdoor enthusiasts with drinking water. The WaterWorks® filters combine innovative filter technology with a rugged plastic housing to create a system that weighs only 17½ oz.

Manual pumping action draws water from its source through inlet hoses into the WaterWorks unit, where particulates and bacteria are trapped. Instead of using chemicals to treat the water, the system employs four filter elements, each of which progressively decrease in pore size to allow for easier pumping and longer element life.

Clean drinking water flows out the unit through a hose, or directly into a wide-mouthed bottle or bag. Long hoses allow users to draw water from sources difficult to access. Moreover, the ergonomic design of the lever-action handle makes it easy to pump a liter of water in 90 seconds. Filter components can be removed for cleaning.

The housing consists of three parts: pump head, body, and adaptor base. "After reviewing technical data on a variety of materials for use in the rugged housing, we specified transparent Isoplast™ thermoplastic resin from Dow Plastics," says Jim Fife, R&D engineer at MSR. "The material gave us the best fit for our application, without resorting to the high cost of a much more expensive specialty plastic."

In addition to being National Safety Foundation (NSF) approved, the hydrolytic stability and chemically inert nature of Isoplast resists attack by food substances. If needed, the housing can be sterilized.

And, adds Fife, "The design of the unit and the clarity of the material make it easy for the user to see how the system works and to recognize when cleaning is required."

Plastics give home/water heating system new scope

Dallas-- "Form, fit, and function" were the major challenges faced by Lennox Industries, Inc. in the design of a new high-efficiency home and water heating system. Plastics helped meet the challenge.

The CompleteHeat system consists of separate air- and heat-handling modules: The heat module serves as a storage battery for the heat needed for space heating and hot water; the air-handling module provides comfort conditioning to the home. A small pump draws hot water from the heat module and circulates it inside the air-handling module. Here, a blower and heat exchanger transfer the heat from the water to the air, where it is used to heat the home. Once the heat has been transferred, water is recycled through the heat module to be heated once again.

"When we started work on this project, we were literally staring at a blank sheet of paper," says Dave Moody, marketing specialist for Residential Heating Development at Lennox. "Since our experience with plastics was limited, we turned to Dow Plastics to assist us with the design."

At the time, Dow Plastics was working with another division within Lennox. According to SuAnne Ireland, application development engineer for Dow, Lennox knew the intricate design of the top cap assembly would not be possible with metal. But Lennox designers had reservations as to whether or not plastics could be used cost effectively in the application. Color-matching the familiar "Lennox beige" paint also proved critical to the material selection.

"Based on our assessment of the dimensional stability requirements of this application, we recommended that Lennox specify an amorphous polymer, rather than a crystalline material," says Jim McGettrick, project leader for design support in technical service and development at Dow. The ultimate choice was Magnumª ABS resin: Magnumª 275 for the system's exhaust/drip pipe assembly and for the flue vent valve, and Magnum 343 for the air intake assembly, because of its longevity, weatherability, and chemical resistance.

Dow then met with the molder, the Thermoplastic Div. of Goshen Rubber, Englewood, OH, to provide technical input for part and tool design, and to assist in improving the productivity of the molding process. Successful production of the system is credited, in part, to Lennox's concurrent engineering strategy. "Calling on the materials expertise of Dow and the molding experience of Goshen Rubber enabled Lennox to speed the product development cycle," McGettrick explains.

Process-management software boosts design productivity

Munich, GERMANY-- Can process-management software make concurrent engineering and business re-engineering more feasible?

That was one of the questions engineers at Daimler-Benz Aerospace (DASA) sought to answer in a series of recent tests. Their preliminary conclusion: Yes.

The process-management tool they used in the tests is Siemens Nixdorf's newly introduced SIFRAME. As part of the CONSENS (Concurrent Simultaneous Engineering System) project of the Commission of the European Union, DASA engineers integrated Dassault's CATIA, SDRC's I-DEAS, DASA's own ODIN analysis package, Sherpa's product data management software, and tools developed at Belgium's University of Leuven into SIFRAME.

"Preliminary results show that SIFRAME can demonstrate process- and data-management capabilities quickly and effectively," says DASA engineer Josef Vilsmeier. Implementation of a framework such as SIFRAME, he estimates, could eliminate about 50% of a DASA engineer's administrative work.

SIFRAME is a client/server UNIX-based system that works with CAD/CAM, product-data management, MRP, shop-floor, and other software. Engineers can use it to manage dependencies and track associativity throughout an entire product-development cycle.

DASA engineers now are testing the possibility of controlling development of a component from conception to finished design with SIFRAME. The test involves design of a wing box.

For now, DASA is happy with preliminary results. "SIFRAME easily integrates existing UNIX-based tools, facilitates teamwork and communication, and lets engineersbe more creative and productive," Vilsmeier says.

Meanwhile, Siemens Nixdorf has launched a concurrent engineering initiative in North America combining its own technological expertise in process management with partners such as Deloitte & Touche. The initiative includes a Concurrent Engineering Center, a Competency Center, and implementation of SIFRAME.

Intel adopts flash-memory software

Tel Aviv, Israel-- TrueFFS flash-memory operating system from M-Systems Flash Disk Pioneers Ltd. overcomes the disadvantages of using flash memory as a disk drive. These include: slow erase times, need to erase memory before rewriting, and dealing with memory in large blocks. Intel-one of the world's largest flash-component manufacturers-had previously used other software, but has now decided to use TrueFFS software for its flash-memory product line.

M-Systems introduced the industry's first flash-memory disk in 1990. Flash is a nonvolatile semiconductor memory technology that uses no moving parts. TrueFFS software is DOS-compatible and fully emulates a magnetic hard disk in a manner that optimizes the architecture of flash memory. This lets flash-memory cards and other flash products function as long-term read/write devices in a way that is transparent to the user. Last year, TrueFFS was recognized as a standard by PCMCIA (Personal Computer Memory Card International Association).

"Choosing flash for data storage provides the most rugged and efficient solution to a designer needing high reliability, low power consumption, and high speed," says Bruce McCormick, product marketing manager of Intel's Memory Components Div. "M-Systems' TrueFFS is an easy-to-use software solution for using flash memory for data storage."

Says M-Systems President Ivo Adam, "Using a CPU and flash is cheaper and easier than using a microcontroller." He predicts there will be dozens of these systems in every home-in microwave ovens, phones, and other appliances. Other flash-memory applications include industrial controllers, robotics, vending machines, bar-code readers, networks, hand-held computers, and medical diagnostic systems.

Mid-range CAD offerings expand

Waltham, MA-- Engineers looking for a lower-priced CAD product now have one more option to choose from-and it's offered by what many consider an unlikely source.

Parametric Technology Corp. (PTC) has introduced Pro/JR., an $8,000 version of its high-end, industry-leading Pro/ENGINEER.

Like its bigger cousin, Pro/JR. is a parametric, feature-based solid modeling system for design through documentation of mechanical parts and assemblies. It's fully compatible with the rest of the Pro/ENGINEER family of products, and runs on a wide range of PCs and workstations. PTC says it has about 40% of the robustness of Pro/ENGINEER for about 40% of the price.

PTC Chairman and CEO Steven C. Walske says Pro/JR. is aimed at an emerging mid-range market of 400,000 to 600,000 users who want to migrate from low-end, 2-D drafting products to more sophisticated 3-D solid modeling. "Pro/JR. provides an affordable way for them to get started in the Pro/ENGINEER product family," he says, noting that the product is upgradeable to Pro/ENGINEER.

But, say at least two industry analysts, a limitation is that models created in Pro/ENGINEER cannot be sent to Pro/JR. The reason, says Stephen Wolfe, publisher of the CAD Report, is not technological, but based on marketing. Gisela Wilson, of International Data Corp., says that decision limits users' freedom and reveals the company's intent to migrate users up to the high-end product. PTC doesn't deny that, and says that since all its software runs on Windows NT users can bring models home and work on them on their own PCs.

Though Pro/JR. has several technological limitations-such as the inability to sweep profiles along multiple or three-dimensional trajectories, and an inability to create blends between blended surfaces-it is a "fairly complete system," says Wolfe.

"It's a lot of technology for the simple parts you can build with it," adds Wilson. In fact, she says, "it's not a true mid-range product. It's really a high-end product scaled back."

Software juggles data from many sources

Rouen, FRANCE-- Is all this paperwork necessary? This is the central question that plagued engineer Roger Nicolle of TRT Philips after examining his facility's project management methods.

Engineers at TRT's Rouen-based production facility would create CAD drawings, print them out, and route them throughout the company for additional comments and instructions-a process taking two to three days for each drawing, delaying the development process.

Sure that there was a better approach, TRT Philips invested in project management software that has increased productivity in the division by "five to ten times," states Nicolle, a technical data processing engineer.

A developer and manufacturer of telecommunications hardware equipment, TRT required a system that would allow engineering teams to create compound documents that integrate CAD drawings with spreadsheet information and regular text. Employees would then be able to route them through the facility for each member of the team to review, revise, and pass on.

"If this wasn't enough," says Nicolle, "we also needed to create customized applications, such as quality assurance applications, that integrate seamlessly with the new workflow."

Using the Applixware integrated software suite, TRT engineers can now route documents between engineers and production, with mark-ups and comments done in real time without the extra steps necessary with paper-based copy. CAD drawings generated on Sun workstations can also be imported seamlessly with documents from such PC-based applications as Microsoft Word, comments Nicolle. "The process that previously took two to three days now takes ten minutes."

Nicolle has also used the software to create a customized application based on Applix Spreadsheet. Employees enter quality-related information, which is then automatically entered in a back-end spreadsheet that is transparent to the user.

TRT plans to implement the software system at its other research locations in Lannion, Brive, and its headquarters in Paris.

Polycarbonate survives hair-dryer heat

Kronberg, Germany- Most consumers never give the polymers in their hair dryer a second thought. However, engineers at Braun AG did. In fact, to help ensure that its hair dryer would stand up to years of use and possible abuse, Braun conducted some serious testing of several engineering resins and their various grades. Special polycarbonates come out the winners.

Based on this testing, Braun selected Makrolon® polycarbonate and Apec® high-heat polycarbonate from Bayer AG, Leverkusen, Germany, for its Silencio PE 1600 hair dryer and diffuser.

"While these resins were chosen because of their excellent performance in the torture tests, their inherent properties played an equally important role in their selection," says Winfried Paul, product manager for Apec. These properties include: heat resistance and good processability, colorability, luster, color stability, surface hardness, gloss, and scratch resistance.

A resin like ABS would have sufficed for some of the less thermally demanding parts, Paul adds. But the heat resistance demanded by the dryer required a resin with a high heat-deflection temperature.

Makrolon 2805 polycarbonate has a heat-deflection temperature of 137.8°C (280°F at a 66-psi load), which proved sufficient for the dryer housing, fan assembly, and standing vanes. But because the diffuser was right in the path of the hot air, it demanded a resin with an even higher heat-deflection temperature.

Enter Apec DP9-9351 with a heat-deflection temperature of 162.2°C (324°F). The resin did not deform during testing, even after prolonged exposure to the hot air generated by the dryer. In addition, Apec works well in molds originally designed for more traditional polycarbonates, says Paul.

Braun chose a gloss finish for the Silencio, marketed to consumers in many European countries. However, it wanted another look for the high-end models. Braun settled on a matte finish as the right treatment to meet this need. Rather than modify the tool to produce such a finish, Braun sandblasts the molded parts in order to obtain the matte look. Sandblasting, says Paul, would not have been possible using a resin in the ABS product line.

Now, Braun has a winning hair-dryer design on the market that assures its users they have an appliance that will give them years of service, even if they drop it on hard porcelain sinks or tile floors.

Lubrication critical to cable design

Evry, France--Cable routing and design have become increasingly difficult in newer vehicles, especially those with transverse-mounted engines. Gearshift cables, in particular, must transmit a critical motion within consistent tolerances-hundreds of thousands of times. And the number of direction changes needed in current vehicle designs can impair the accuracy of shifting action. Unacceptable vibration and noise levels also can result.

With these considerations in mind, Acco France has designed a new-generation cable that transmits both pushing and pulling forces, such as those required in changing gears. Space limitations in engine compartments played a major role in the development.

A key ingredient in the reliable, long-term performance of the new cable design hinged on the selection of a lubricant that would minimize friction between the cable core and sheath. The lubricant had to withstand temperatures of 150°C (302°F) in the engine compartment and near exhaust manifolds, and also retain its lubricity in extreme cold.

Conventional petroleum products offer a low coefficient of friction initially, but they often become resinous under high-temperature conditions. Reduced lubricating qualities over time can cause a loss of operating efficiency and wear on the cable.

Acco France engineers found the solution in Dow Corning's Molykote® 33, a synthetic grease based on silicone technology. (U.S. engineers should specify Dow Corning® 33 Extreme Low Temperature Grease.) The lithium-thickened silicone lubricant offers a service temperature range of -73° to 200°C (-100° to 400°F).

The Acco cable design is already being used in Renault's top-of-the-line Safrane vehicles. The space-saving cable design offers flexiblity, reducing shift-lever vibration and passenger compartment noise. The lubricant also helps ensure maintenance-free operation, despite thousands of high/low temperature cycles and millions of gear changes.

MMIC technology a boost to telecommunications

Paris, FRANCE--Monolithic Microwave Integrated Circuits (MMIC) stole the limelight at the recent Hyper "95 exhibition here.

The electronic technology, a key component in mobile communications products, is currently based on either gallium arsenide or silicon technology. MMICs of the future are likely to favor GaAs, as two new products from Hewlett-Packard and Philips Microwave showed.

Philips exhibited for the first time a GaAs MMIC which includes both an enhancement-mode and a depletion-mode transistor. As a result, the chip can be used both for receiving and transmitting applications, thus optimizing power consumption, reducing costs, improving performance, and occupying less space, according to Derek Smith, marketing manager. Its GSM (group special mobile) front-end with a power amplifier, low-noise receiver preamplifier, antenna switch, and power sensing circuit make it ideal for GSM communications, Smith says.

Hewlett-Packard also launched its new range of GaAs MMICs, aimed at applications including cellular telephones, wireless local-area networks, and data collection.

"The chip has been designed to fit into the SOT-363 package measuring just 4.2 sq mm," explains Alan Rixon, applications engineer. "Most competing products are in the SO-8 package, which measures 30 sq mm." (The SOT is the international standard size of casing for electronic components.)

Hewlett-Packard is also one of the few to use PHEMT transistors, adds Rixon, because they enable more efficient biasing at low voltage than the more common MES FET transistors.

Modeling software gets toys to market faster

Lons-le-Saunier, FRANCE- Faced with increasing low-cost imports from Asia, toy manufacturers in Europe are searching for new technologies to stay competitive.

Take, for instance, Monneret Jouets, a toy company here. The company used CAD/CAM and design modeling software to create its new Rondo dolls' pram and cut 20% off product development time.

Just prior to introducing CAD/CAM into the development cycle, designers worked at drawing boards. NC machining programs were prepared manually.

Monneret Jouets installed an Intergraph CAD/CAM system that incorporates three networked UNIX workstations. The technology allows engineers to easily create and modify designs, and then convert their work into mold designs and machining programs.

The Intergraph system has also improved product quality, says CAD/CAM manager Olivier Laplace. Before they installed CAD/CAM technology, it was often impossible to manually prepare NC programs for the exact shapes designers specified. Engineers were forced to simplify the geometric forms. Any form, however complex, can now be scanned into the CAD/CAM system.

By modeling the plastic injection molding process before finalizing product design, Monneret has also reduced the quantity of plastic in each Rondo pram.

"We thought we needed a 2.7 mm (0.11 in) thickness of plastic over the whole pram frame, but the rheological study showed that 0.5 mm (0.02 in) was sufficient for the majority of it. Only a few critical areas required 3.0 mm (0.12 in)," Laplace says.

Moldflow software used to model the flow of plastic shows the pressure variations in the mold and how the distribution of stresses in the molded plastic part varies when different loads are applied. This lets engineers confirm that international standards are being met.

Overall, each Rondo pram uses 30% less plastic than originally expected and takes 30% less time to mold, Laplace says.

-Anna Kochan European Editor, France

ASICs are key in new quieter, affordable dot-matrix printers

Torino, ITALY--Dot-matrix printer noise levels have increased over the years as manufacturers used smaller pins and more of them in the print-head to improve the resolution of the dot matrix. Most office dot-matrix printers now have 24 pins of 0.2-mm diameter-arranged in two parallel columns-while simple 9-pin models use a single vertical column of 0.3-mm diameter pins. A 9-pin dot- matrix printer generates around 54 dB, while a 24-pin model reaches up to 56 dB. Print heads are designed for a certain firing frequency, from 900 Hz to 3,000 Hz, according to the required print speed.

Noise level drops. Engineers at the printer division of Ing. C. Olivetti & Co. Spa have found a way to economically reduce the noise level. The solution: a 9-pin print-head in which the pins do not fire simultaneously. A 24-pin version has also been produced.

The engineers rearranged the pins of the 9-pin print head in a slanted line; they formed two columns into a diamond or lozenge shape (functionally equivalent to two parallel slanted lines) for the 24-pin model. The advantage of these arrangements is that pins fire in quick succession instead of simultaneously. This results in reduced noise peaks and a smoother noise profile.

Eliminating the noise peaks brings the average noise level down by 2 dB for the 9-pin head and 4 dB for the 24-pin design. The differences may not seem great, but they bring both print-heads under the 55 dB limit, which is becoming widely accepted as a recommended noise limit for office environments.

Electronics: the key. Changing the print-head design is an idea that has been around for at least 10 years, admits Flavio Balasini, head of R&D for impact printers at Olivetti. What has prevented printer manufacturers in the past from implementing a slanted print-head design is the complex electronics that are necessary to accurately fire pins in rapid succession as opposed to simultaneously.

Now, advances in very large-scale integration semiconductor techniques mean that this circuitry can be implemented more cost-effectively. A single custom application-specific integrated circuit (ASIC) chip contains the 11,000 logic gates required to contain the pin-firing patterns for the slanted head, against just 3,000 for the traditional vertical-column print-head. The driver circuits for the print-head coils that fire each pin are also more complex than for a simpler vertical-column design.

The ASIC technology has brought down the cost of the electronics to drive the low-noise print-heads to about $16.

Now, the new heads can be cost-justified even on Olivetti's lowest-priced dot-matrix models.

How 'slanted line' reduces noise

With the conventional dot-matrix print-head, the pins are arranged vertically and fire simultaneously. For example, to print the first vertical element in the printed character "A," four pins in the 9-pin head fire simultaneously. The print head moves 1/60 of an inch and prints the dots in the second column of the character matrix. The noise waveform consists of a sharp peak as four pins hit simultaneously, and then silence until the print head reaches the second column.

With the new arrangement Olivetti engineers developed, the character matrix is the same as before, however, the pins in the print head are offset 1/720 of an inch.

To print the same four dots of the first vertical element in the character "A," the process is as follows: the leading pin fires; the head advances 1/720-inch so that the second pin is directly above the first printed dot; the second pin fires; the head advances another 1/720-inch, and so on. The resulting printed pattern of dots is exactly the same, but the noise waveform is different: instead of one large peak there are four much smaller peaks in quick succession.

-Geoff Nairn European Editor, Italy

Electronics manufacturer reaps benefits of 3-D CAD

Hannover, GERMANY- Sennheiser, a manufacturer of wireless microphones and pocket-sized mini transmitters, among other electronics equipment, uses 3-D CAD as a tool to create its sophisticated electronic products.

Sennheiser began using Hewlett-Packard's PE/Solid-Designer in the fall of 1993, and immediately saw improvements compared to the system it formerly used. For instance, engineers can free-form surfaces along with rule-based bodies and faces to define the solid model, explains Michael Nickel, system support specialist at Sennheiser. Wireframe, surface, and solid geometries can be combined at will.

The company, eager to shift from 2-D to 3-D design, put the product to the test right away in developing a new headset.

Prototype in 2 days. Once a model of a new product design is tested and corrections made, it is digitized and the data is loaded into PE/ME10. The system converts the data into B splines, which are virtual "slices' through the outer skin of the new headset.

The Loft command of the modeling system applies a free-form surface over this ribbing. The digitized design model is then turned into a CAD solid model. Engineers then modeled the inner walls, attachments, and connection geometries of the earphone. Result: a complete solid model of the entire product that can be displayed with shading for purposes such as documentation.

The polyhedral mesh generated in SolidDesigner from the solid model can be used without further modification as the basis for rapid prototyping-which can be created in just days. Assembly testing of the components then begins immediately.

"The function tests with the prototypes produced very close approximations to the acoustic properties of the finished product," Nickel says. "The process is much faster and more convenient than conventional prototyping in the traditional sense, and the savings are enormous," he adds.

Nickel says the time from initial product concept to production was just nine months-the headset came on the market in August 1994. Before SolidDesigner, the design cycle for a comparable product would have been two years, he says.

The 30 design engineers at Sennheiser are migrating to the new 3-D solid modeling program at a steady pace. Nickel says the product's user interface is so intuitive that new users are modeling on their own after only one to two days. Another benefit of the product is since the company was already using PE/ME10 and PE/ME30, all data can be used without conversion.

"The new system lets the engineer work directly on the solid model," Nickel says. "He can pick individual parts without having to execute complicated Boolean operations for each modification."

Automakers show off their smart technology

Paris, FRANCE- A car from Mercedes that "drives itself" and an intelligent cruise control system from Porsche were among the highlights of the First World Conference on Transport Telematics Applications and Intelligent Vehicle-Highway systems.

Under the aegis of ERTICO (Europe), VERTIS (Japan), and ITS AMERICA, automakers and suppliers gathered to show off their leading edge technologies aimed at improving transport safety and efficiency.

Members of Prometheus (PROgram for European Traffic of Highest Efficiency and Unprecedented Safety) program, which includes Europe's leading automakers and top electronics and automotive suppliers, presented the results of eight years of research.

Here is a sampling of the technological highlights.

"Self-driving' Mercedes. Daimler-Benz presented its "computer vision" car, the VITA II, which features autonomous, automated driving. While the car "drove itself" for entertainment value, the main objective of the technology is to help drivers avoid accidents, Mercedes says.

The car's technology is based on 66 RISC processors from Inmos, (an SGS-Thomson subsidiary in the UK), Texas Instruments, and IBM/Motorola, and realtime parallel processing systems from Parsytec.

The Vita II uses 18 video tracking cameras strategically positioned around the car to collect and digitize data on the driving environment, explains Dr. Walter Ziegler, the project's leader. In the future, some of the cameras will be built around a special video chip developed by the Institute of Microelectronics at the University of Stuttgart. The cameras need a high dynamic range, which is critical to recognize objects under extreme light and dark conditions or when there are hard shadows, Ziegler says.

Since each camera records a million-pixel image every 20 milliseconds, data reduction must be performed by various image processing modules. These modules actually recognize other vehicles, obstacles, lane markings, and traffic signs, and identify them as such. The modules were developed at Daimler-Benz in cooperation with researchers at universities in Bochum, Munich, and Koblenz. Researchers are working on the more difficult task of the modules recognizing humans and animals.

The reduced data is held in a dynamic database, and is used by the system as the basis for behavior decisions (such as where to steer, or whether to brake, accelerate, change lanes, or pass). Actions are implemented by the vehicle control system using sensors and actuators. Daimler-Benz developed a special electronic steering wheel for the Vita II; as with standard cruise control, the driver can override the system any time.

Porsche grips the road. "The friction monitoring system as a key technology is an important contribution to making traffic safer," explains Helmut Flegl, Director of Advanced Engineering, Porsche.

Porsche's system of the future, the Intelligent Speed and Distance Control System, incorporates friction monitoring to warn the driver of hazardous road surfaces and vehicle distance conditions. It also takes driving style, vehicle specific data, and "run of the road" data into consideration.

"The basic design problem of the friction monitoring system was to develop a sensor system that is able to continuously detect the road surface conditions with a suitable in-vehicle system," says Uwe Reuter, of the Advanced Chassis Group.

Using the information on the condition of the road surface, the system makes a prognosis of the potential grip level between the tire and the road. The objective is to warn the driver about the road surface condition with respect to the maneuvering capabilities of the vehicle before the tires loose their grip.

To determine road wetness, sensors installed in the arch liner behind the wheel record the structure-borne sound signals that result when water sprays up from the tires. Incorporating vehicle speed information, the amount of water on the road can then be calculated. The road's texture is basically based on the same principle, but the sensors are placed on the rear axle hub-carriers. Slippery conditions are determined using a friction force/slip quotient.

Once the road conditions are determined, the system can predict the "grip" for the entire vehicle using a friction coefficient. All of this is calculated based on tire- and vehicle-specific modeling in a realtime processing system on a 68020 CPU.

The friction monitoring system is incorporated in the Porsche Autonomous Intelligent Cruise Control (AICC) system. The AICC incorporates sensors for measuring wheel speed, longitudinal and lateral vehicle accelerations, steering wheel angle, engine speed, throttle butterfly angle, road surface texture, and water depth. The AICC, which is linked to the regular cruise control, can be turned on or off. It cannot be activated, however, under "very slippery" road conditions. A new generation of sensors is being developed to deal with bad weather, Porsche reports.

-Adele Hars European Editor, France

Fluidic valve borrows concept from chip design

Burgess Hill, UK- Even though fluidic control as a concept is simple, steps taken over the years to reduce size, improve performance, and lower expenses haven't been successful.

Machining and assembly operations in particular have pushed up costs, if not for the manufacturer, then for the user who has to install the device with various fittings.

By borrowing concepts from silicon chip design, a completely new style of fluidic valve known as the "Isonic" system has been developed as the result of transatlantic cooperation between Mead Fluid Dynamics Inc. in the U.S. and Abex Mead Ltd. located here.

Unique design. The valve is designed as two half shells with each half containing the logic channels and space for drop-in components. The shells are molded from glass-filled polyamide so the channels can be aerodynamically designed for efficiency rather than made angular to suit production processes. By combining a unique bisectional "half-shell" design with computer-controlled ultrasonic welding and high-quality molded parts, the Isonic valve design eliminates the need for drilling and machining internal flow channels.

One feature of the design is the ease of connection to the air supply. Instead of the angular passages of most conventional valves, Isonic's internal channels are aerodynamically shaped for maximum air flow and minimal internal friction. Replacing rigid flow passages with previously unattainable curved channels brings about a reduction in air turbulence.

The two body halves are ultrasonically welded with the internal parts permanently sealed without gaskets or adhesives. The 1000 series of solenoid valves measure adds 32 x 44 x 16 mm (1.3 x 0.5 x 0.6 in) with two orifice sizes; working pressure to 8 bar; and up to 1.3 Watts power.

Small relay thwarts thieves

A miniature relay from Siemens Automotive Systems Group, Munich, Germany, is being used in an application to combat car theft. Siemens' engine immobilizer blocks operation of a car's starter, fuel line, ignition, and central engine control until the ignition key sends the right code to the control unit via a transponder. The P1 miniature relay, the SMD version of which measures 13.5 x 7.9 x 8 mm, separates the diagnostic bus from the engine immobilizer during the start phase. Specially selected plastics used in the SMD version aren't affected by temperature and are non-degassing. The P1 is registered by the UL and CSA, and is flameproof in accordance with DIN IEC 695. The relay is also used in measuring, control, regulating, and processing equipment, as well as in the telecommunications, signaling, and medical fields.

-Norman Bartlett European Editor, UK