Commercial aerospace and defense companies ensure avionics and other electronic systems with test and measurement tools

Feb. 18, 2009
Test and measurement tools for defense and aerospace applications are crucial to prevent failures that could put lives and expensive equipment at risk.

By Courtney E. Howard

The test and measurement of electronics is an important part of any development and production process, yet testing for military and aerospace applications is especially critical because failures might put lives and missions at risk, recognizes John Barfuss, aerospace & defense program manager at test giant Agilent Technologies Inc. in Palo Alto, Calif.

"If a business person's phone stops working it is an inconvenience but if a soldier's radio quits working, it could leave him in grave danger," continues Barfuss. "If a cellular base station breaks it may cost the provider thousands of dollars. If a satellite payload breaks it could cost millions."

With military and civilian lives and billions of taxpayer's dollars potentially on the line, test and measurement is at the forefront in the minds of systems designers, systems integrators, and end users in the military and aerospace market. Makers of test and measurement solutions serving the mil-aero community continue to advance the technology, keeping pace with avionics other technologies and the standards and deadlines to which they must adhere.

Time is of the essence

Much has been written about warfighters in the field waiting for armaments. In an effort to deliver ample electronics systems and supplies rapidly that are safe and reliable, industry organizations are partnering to speed and perfect test and measurement processes and procedures -- and they are accomplishing these goals through automation.

Engineers at Agilent Technologies, Raytheon Co. in Waltham, Mass., and the U.S. Navy have teamed to develop an automated test system for Raytheon's system missile business. The joint efforts of these three organizations culminated in the Presidio Automated Test Line, considered a breakthrough in testing automation and used in the production of Raytheon's Standard Missile 2.

"The system used Agilent's measurement technology and automation expertise to greatly improve the efficiency of test--cutting the cycle time from 21 days down to seven hours," Barfuss explains.

The SM-2 Presidio replaces 17 test positions and 27 environmental conditioning systems with one automated installation, enabling the achievement of impressive time-savings. Presidio also takes advantage of commercial technologies, such as robotic material handling, multi-plane vibration, universal solid-state test interfaces, and test executive software.

"The Navy benefits significantly from the greater test efficiency that Presidio provides," Scott Reiter, the Navy's SM-2 project director, observes. "This gets missiles in the hands of our sailors that much faster. It is another example of the great partnership that exists between the Navy and Raytheon on SM-2."

The novel system has changed the testing process not only for Standard Missile, but also, ultimately, for Raytheon's entire Missile Systems business, says a representative. "Presidio sets the stage for automation across our business," says Rick Nelson, vice president of operations for Raytheon Missile Systems. "It marks a vital first step in modernizing and streamlining all of our operations processes."

Hardware assurance

Software verification has long been a requirement, yet only in the past few years has hardware assurance been a focal point. The Federal Aviation Administration (FAA) is enforcing DO-254, Design Assurance Guidance for Airborne Electronic Hardware, a standard for complex electronic hardware development published by RTCA Inc.

The DO-254 standard ensures the compliance of complex electronic hardware -- such as field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), and application specific integrated circuits (ASICs) -- in airborne systems. With DO-254, the FAA and the industry at large acknowledge that hardware and software in avionics systems, in particular, are critical to safe aircraft operation.

"Verification (usually referring to the testing and analysis done during the design process) and test (usually referring to the testing of the actual hardware item) are important in every industry, but are critical in mil-aero," admits Michelle Lange, DO-254 Program Manager at Mentor Graphics Corp. in Wilsonville, Ore. "Certainly in avionics, and often in military and other aerospace applications, failure is not an option. Failure means lives are at stake, or at the least, a lot of taxpayer dollars wasted. So, thorough verification throughout the design process and high-quality testing of the actual hardware device are imperative to ensure that bugs do not escape and risk lives and dollars, and expose companies to high liabilities."

Hardware verification, though definitely a move in the right direction, is causing a great deal of cost, concern, and confusion among companies that must comply with the certification standard. Lange and her colleagues at Mentor Graphics have joined the campaign to evolve the industry to use proven methods, and they are working closely with the FAA.

Mentor Graphics officials, recognizing the challenges DO-254 poses to individual businesses, have issued and made readily available a white paper targeted at helping executives understand and work through the business issues associated with DO-254. The Institute of Electrical and Electronics Engineers (IEEE in Piscataway, N.J.) white paper is available online at Lange and other experts discussed the standard earlier this year at the Integrated Electrical Solutions Forum (IESF), an event organized by Mentor Graphics for Electrical and Electronic Systems Design, Modeling, Simulation, and Analysis within the military/aerospace industry. (Visit for more on the company's scheduled events.)

Mentor officials also are participating in the Testability Management Action Group (TMAG), aimed at improving the visibility of testability to higher levels of management, explains Ron Press, design for testability (DFT) technical marketing manager, Mentor Graphics Corp. TMAG comprises professionals who believe that success for testability in general, and DFT in particular, requires the involvement and the support of management at all levels. TMAG provides information intended to help executives establish the benefits of testability and DFT.

Avionics test and verification

Professionals in the avionics field understand well the value of DO-254, even if many find compliance challenging. Roughly 200,000 connections thread throughout aircraft, bridging legacy, outdated, homegrown, commercial off-the-shelf (COTS), and customized systems, notes Martin O'Brien, general manager of Mentor Graphics's Integrated Electrical Systems Division in Newbury, England. It is imperative that each of these connections and integrated components and systems are thoroughly tested.

"Almost every aircraft that rolls off the production line is to those that rolled off just an hour earlier," O'Brien adds. "The vehicle that rolls off the assembly line does not reflect what is in the original design." It is typical to have 80-plus changes to electronic and electrical systems take place throughout the design cycle. These changes need to be tracked, and a relationship between the logical design and the physical design maintained throughout the process, he insists. Using Mentor Graphics design tools, systems integrators need only load the systems into the software. With the push of a button, the software connects the systems automatically, and then evaluates and assesses the overall, integrated system design.

A variety of today's prime contractors, subcontractors, and systems integrators employ Mentor Graphics's products to automate the design, verification, and testing of military and aerospace electronics -- "from the smallest PLDs to the most complex ASICs, through board-level design, system level analysis, embedded software, and even the electrical interconnect at the top level vehicle design," says Press.

"In the DO-254 domain," continues Press, "we have tools that are used to design the FPGA or ASIC components at the register transfer level (RTL), verification tools from the most basic simulator to the industry's leading-edge advanced verification methodologies, safety-focused synthesis for conversion of RTL code to gates, and a requirements traceability tool to tie the system and component requirements to the implementation and verification of those requirements."

Engineers at Rockwell Collins in Cedar Rapids, Iowa, are using Mentor Graphics's verification tools on complex avionics projects that have to be developed in compliance with DO-254 standards. Similarly, Thales personnel in Newbury, England, employ Mentor Graphics solutions behind the scenes in their "Workbench" flows. For example, says Press, the FPGA Workbench flow--containing various Mentor tools, including HDL Designer, ModelSim, and Precision Synthesis--supports DO-254 and other best practice and standardization requirements.

Aircraft assurance

Bell Helicopter Textron Inc. in Fort Worth, Texas, has standardized on Mentor Graphics's CHS flow in the design of its helicopter wiring systems. Bell is deploying CHS system design, analysis, and integration software, coupled with CHS harness engineering and costing tools.

"This front-to-back CHS flow provides Bell with significantly enhanced engineering productivity by automating time-consuming tasks and providing a means to virtually prototype the electrical architecture before it's built," Press explains. In terms of the vehicle harness challenges, he continues, CHS provides an integrated application suite for system design, analysis, system integration/wiring design and harness engineering, embedded data management capabilities (vehicle configuration management, design comparison, data sharing), productivity-enhancing modern technologies (wiring synthesis, interpretive analysis, diagram synthesis).

"Bell has over 50 years of flight innovation," says Elaine Vaught, senior vice president of engineering at Bell Helicopter. "As a premier aircraft development company, we are constantly improving our processes. Electrical design changes are a key source of engineering costs and are often in the development schedule critical path. CHS will enable our engineers to manage smart design data, to innovate faster with fewer obstacles. CHS is a key component to helping Bell Helicopter address corporate business objectives."

CHS provides engineers an "in-context" design environment, enabling them to interact with data in the context of a particular vehicle or configuration and eliminating the need for manual checks to ensure complexity compliance.

"By adopting CHS, Bell Helicopter is taking a strong position in the deployment of these modern technologies," says O'Brien. "The electrical system architecture is complex in aircraft. By standardizing on CHS, Bell will achieve cost, reliability and time-to-market advantages in terms of part number control, design error reduction, and architectural optimization."

Environmental testing

Without question, it is terribly important to test the final mil-aero product, even if the design and production processes are stringently evaluated and validated. Officials at Lockheed Martin in Bethesda, Md., working on NASA's Phoenix Mars Lander did precisely that, with the help of equipment purchased from Mirion Technologies' Imaging Systems Division in San Francisco.

Lockheed Martin engineers used Mirion's IST-Rees camera systems to test the Phoenix Mars Lander in strict thermal vacuum conditions prior to launch. The Imaging Systems Division develops imaging systems designed to maintain optimal performance in a variety of extreme and hazardous environments, says a company representative.

Lockheed Martin personnel needed a camera system for testing the Phoenix Mars Lander in space-like conditions, to ensure proper operation of the spacecraft's robotic arm and solar arrays. The Lander was tested in Lockheed Martin's large thermal vacuum testing chamber that simulates space conditions with temperature ranges from 20 degrees C to -80 degrees C and high vacuum conditions. Mirion's staff worked closely with Lockheed Martin and supplied three IST-Rees C981 sealed cameras able to withstand the environment of the thermal vacuum chamber.

Stress screening

Environmental stress screening (ESS) is particularly crucial when dealing with mil-aero solutions. It is defined, by a representative at EADS North America Defense Test and Services in Irvine, Calif., as the process of exposing an electronic product or component to stresses in an effort to force latent defects to manifest themselves by failure. ESS can include temperature variations, vibration tests, pressure, and flexibility tests. Developed to help electronics manufacturers detect product defects and production flaws, ESS is widely used in military and aerospace applications.

"Mil-aero systems are the ultimate mission critical systems--critical for safety of crew, passengers, and the general public," says Steve Karlovic, director of major programs at EADS North America Test and Services. "These complex systems must be tested to ensure they meet their operational requirements before use, which requires two things: precision instrumentation (for obvious reasons) and automation (because of the complexity of the task). Mil-aero systems are also generally not disposable and have long operational lifetimes, which require that they be repaired, compounding the test and measurement demands for these systems."

Engineers at Toshiba Corp. Semiconductor Company are ensuring the reliability of its newest 40/45-nanometer semiconductor production technology with the 5032 Environmental Stress Screening System from EADS North America Test and Services, a division of EADS North America.

"Precise junction temperature control is the essential element for environmental stress testing," admits a senior manager in Toshiba Corp.'s System LSI Quality and Reliability Engineering Department. "Without precise temperature control, production test time is wasted and reliability test results are meaningless. EADS's single-phase technology provides the most accurate closed-loop control for our most advanced device technologies."

The 5032 is an environmental stress screening system designed for the semiconductor manufacturing market. "The 5032 offers the benefits of closed-loop thermal control without the complexity and expense of the two-phase refrigeration systems normally used for environmental stress screening testing," says James F. Mulato, president of EADS North America Test and Services.

ESS is important in mil-aero applications to weed out defects in components or manufacturing process, notes Karlovic. EADS provides "chamberless" solutions used in ultra-high reliability mil-aero applications, such as satellite programs, where "burn-in" protocol accuracy and speed are of foremost concern. EADS specializes in such systems for processors, lasers, and subassemblies, he adds.

Correct calibration

Personnel at the U.S. Army's Primary Standards Laboratory (PSL) at Redstone Arsenal, Ala., like many governments, national laboratories, and other organizations, use Primary Voltage Standard Systems to precisely calibrate their electronic systems and components.

The PSL develops and maintains primary standards traceable to national standards, calibrates and certifies customer reference standards, and develops precision measurement techniques. It is accredited by the National Institute of Standards and Technology (NIST) National Voluntary Laboratory Accreditation Program (NVLAP) as a calibration laboratory (Lab Code 105002).

The system employed at the PSL incorporates Primary Voltage Standard circuits from Hypres Inc. in Elmsford, N.Y. Hypres's Primary Voltage Standard circuits were commercialized in a project involving technology transfer from NIST under sponsorship of the U.S. Army Research Laboratory.

"Hypres, at the time, distinguished itself by being the only company in the world that succeeded into turning the inventions of NIST into practical commercial products," says Elie Track, Ph.D., a senior partner at Hypres Inc. The manufacturing challenge was significant, but Hypres was successful. The company delivers circuits that can be used by customers to build their own system, as well as complete turn-key Primary Voltage Standard Systems.

Hypres is the only commercial manufacturer of the superconducting integrated circuit used in Primary Voltage Standard Systems, Track continues. The company's circuits are used in Primary Voltage Standard Systems used by governments, national laboratories, and organizations around the world, including the U.S., Italy, France, the United Kingdom, Australia, China, Malaysia, Japan, England, Canada, Norway, the Netherlands, and Mexico.

Calibration with Primary Voltage Standard Systems is especially crucial for systems and components that require finely tuned performance, reliability, and accuracy, such as those found in defense and aerospace environments. For defense applications, a Primary Voltage Standard System is typically used to calibrate secondary Voltage Standard Systems every six to eight weeks, explains Track. The secondary systems are then brought to the locations of the systems and components to be calibrated.

"Primary Voltage Standard Systems are used for the most fundamental definition of the electrical unit of the volt," notes Track. "All calibrations of voltage eventually have to be referred to such systems. They are based on Josephson junction circuit arrays and produce the ultimate in accuracy for DC voltage calibration. The Primary system, which uses the Hypres circuits, is the only way to provide the fundamental metrology certification required for guaranteeing absolute accuracy."

Communication QC

Reliable communication is imperative, to warfighters in the field especially. Agilent Technologies Inc. has introduced a rugged, portable radio tester that enables one-button testing of FM and SINCGARS (SINgle Channel Ground Air Radio System) radios at the operational and intermediate military testing levels.

"A reliable communication system is critical, so the ability to diagnose and repair radio units either directly in the field or at the intermediate level provides users with added peace of mind," says Tom Burrell, vice president and general manager of Agilent's Signal Networks Division. "The L4600A, which incorporates technology from our commercial radio test equipment used widely throughout the wireless market, enables users to make these advanced diagnoses quickly and accurately."

Agilent L4600A Radio Test Set has advanced diagnostics with one-button operation to speed the troubleshooting, identification, and repair of equipment failures. The single system, able to replace several test devices, can combine a built-in spectrum analyzer, network analyzer, signal generator, or signal analyzer to meet specific testing requirements.

The L4600A features a rugged, sealed, weather-resistant design, magnesium-alloy housing, enhanced RF shielding, and integrated heat distribution. The test set's architecture accommodates expansion and in-field upgrades for adding functionality as newer testing technology becomes available, including JTRS radios up to 2.5 GHz.

Complexity breeds test

The need for advanced, test and measurement systems will only increase in the months and years ahead. In fact, says Barfuss, advances in military and aerospace electronics will only expand the need for test. "Modern designs will include greater functionality and sophistication. This added functionality and complexity will expand the needs of test and will also result in a greater proliferation of devices and applications," he admits. "This is not to say that the nature of test won't evolve or that developments such as built-in-test won't be a possibility and serve to reduce test costs, however."

Barfuss sites the Joint Tactical Radio System (JTRS) program as an example of how complexity increases the need for test and measurement. Its goal, he says, is to use software-defined radio technology to create flexible, programmable radios. "The complexity of these radios and need to interoperate with a wide range of radios and waveforms drives the need for increased test. Regenerative satellites, as another example, are being built with the capability of not only retransmitting data (bent pipe), but also processing and intelligently switching and routing data being sent through the satellite. This requires additional digital demodulation tests." Further, digital processing in radars provides greater sophistication in pulse compression techniques, target recognition, and operational modes--all leading to additional test requirements to ensure proper operation, he explains.

Defense electronics, including wireless devices such as radios, satellite payloads, and radar, are becoming more digital in their design, continues Barfuss. A greater portion of the transmitter and receiver is implemented in the digital domain, enabled by advances in, and the availability of, real-time processing (FPGAs, DSPs [digital signal processors], ASICs), high-speed and high-fidelity digital-to-analog converters, and software. Agilent officials are evolving toolsets to meet design and test challenges as a result. "Agilent signal analysis and generation tools are flexible and are able to test and generate signals in digital and analog form, whether it be digital IQ, digital IF, or in a defined DigRF format," he explains.

"Costs and liabilities are growing alongside device electronics complexity," Mentor Graphics's Lange says. "This leads to more possible errors in the design and manufacture of these devices, and thus greater risks of failure. This is true at the component level--thus the importance of DO-254 adherence and thorough verification as well as testability of the physical devices--all the way up through the boards, systems, and interconnection of systems. To put it simply, it's becoming more and more challenging to ensure modern mil-aero electronics are error-free."

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