Telematics integrates consumer communications and information features including hands-free voice communications, navigation, in-car computing, and wireless networking with the standard functions of automotive entertainment systems. Experts predict that telematics will see an exponential revenue growth in the next 10 years, allowing automotive manufacturers to provide consumer-rich options depending on car class and market. With its evolving set of product features, telematics presents unique challenges for global design and manufacturing test teams. Designing for consumer appeal and durability and meeting time-to-market and cost targets for these scalable product features require flexible test platforms and tools.
Car manufacturers have approached this combination of technologies with varying degrees of complexity. Some manufacturers see the future of telematics as voice- and audio-based services controlled by the touch of a button or more safely operated by vocal commands from the motorist.
For example, a motorist can make a hands-free, voice-activated cellular call using services based on international wireless technologies such as code division multiple access (CDMA), time division multiple access (TDMA), or global system for mobile communications (GSM) while receiving real-time global positioning satellite (GPS) navigation information on a visual display. Motorists can access other services such as e-mail, music selection, and emergency distress systems using voice-driven browsers. With other approaches, a more distributed solution can link in-car computing, navigation, and wireless networking to cell phones, personal digital assistants (PDAs), and notebook computers using the Bluetooth wireless standard.
With this convergence of technology, the challenge is building an affordable, flexible, and scalable test platform that ensures the telematics features meet worldwide quality, safety, and technological standards. How do you design a test platform that can support such a broad range of evolving verification and production requirements?
The Acterna A.T.E. Systems Division answered this question by working in close cooperation with Visteon, a leading telematics manufacturer and member of several expert groups within the automotive industry driving to implement telematics technologies. The companies shared many common test goals and concepts in developing an open-architecture, extensible test platform to support many variant telematics products from design through end-of-line manufacturing test (Figure 1).
Visteon required the test platform to be PC-based and use an off-the-shelf test-executive development environment compatible for global users and configurable for future products. At the same time, the test platform had to comply with strict hardware and software requirements for Visteon interfacility concerns such as health and safety, power distribution, standard graphical user interface (GUI), and data handling. The result: a test system with reusable test software and instrumentation tool sets that Visteon uses to meet specific design verification and production test requirements.
Traditionally, because their test requirements have been at odds, many design verification engineers and manufacturing test engineers have independently built their own test systems with tools familiar to their specific areas. By using hardware such as VXI, PXI, and SCXI and software such as National Instruments’ TestStand™ and Microsoft’s Windows NT™, Acterna and Visteon developed a telematics test platform valuable to both design verification and manufacturing test engineers.
For example, design verification engineers need to test evolving functionality of their prototypes while efficiently managing characterization test results on multiple units under extended environmental stress profiles. Manufacturing test engineers are concerned with providing process verification, building the product correctly, and verifying functionality and quality. Test solutions with tools that support root cause analysis, change management, and operator ease of use increase the capability to meet quality standards in a high-volume manufacturing environment.
Telematics Testing Examples
The telematics group at Visteon designed and developed a navigation radio with optional features that required next-generation test platforms. The new telematics product had to be subjected to a number of automated environmental acceleration and durability tests.
For the test, the user places multiple UUTs in a chamber interfaced to the new test platform and performs parametric and functional testing of each UUT. The test system controls the UUT mode settings via a remote-command message set and bus emulator.
Test sequences exercise the UUT feature modes such as AM/FM, navigation, and vehicle interface I/O. With the TestStand GUI, the user selects a sweep or step test method. Typically used for design characterization, sweep tests generate and provide the means to record many test points from 1-µV to 2-V RF signal strength. Used in durability or production testing, step tests generate and record specified test points within this RF level range.
Navigation and Display Test Strategy
To achieve real-time, turn-by-turn navigation, the Visteon Navigation Radio contains an internal gyro to supplement the GPS signal and CD-ROM map database. Durability test sequences subject the UUT to environmental stress profiles while using parametric testing to measure the gyro output voltage level during simulated road turns.
A complex chamber fixture rack holds the UUTs in stable positions while rotating to set directions. The test system uses a PXI-7344 motion controller card and servo amplifier drive from National Instruments to control the motor mounted on the fixture rack.
To visually monitor and log the LCD of multiple UUTs, Acterna selected National Instruments’ IMAQ™ Vision Software and Hardware for further automation and closed-loop capture of test results from the environmental test system. During the durability test, an environmental temperature chamber, which houses the telematics units, subjects the units to a wide range of temperatures.
Using automotive bus emulation, the tester verifies each unit’s operation with digital, analog, and functional test cases. A digital camera checks operation of the LCD for brightness, output accuracy, and messages during these environmental tests. Automating the long process frees the design verification engineer from personally monitoring the tests and logging and analyzing the results.
Audio, AM/FM Test Strategy
An AM/FM generator, an audio analyzer, and a radio broadcast data system (RBDS) encoder perform audio component stimulus and response test and measurement. Navigation, which includes GPS and gyro motion features, is tested through either rack-mounted or PXI/PCI instruments that simulate and measure the respective signals for each of these functions. Many of these VXI, PXI, and GPIB instruments are switched to multiple UUTs through a low-noise RF patch panel controlled by the TestStand GUI running LabWindows/CVI software.
In addition, from the design-verification durability tests, manufacturing test engineers now can reuse libraries of test code, drivers, and communications protocols developed by the design engineers. Because these basic structures of the audio, communications, GPS, and image-acquisition tests already exist, less development time and expense are needed to bring the tests to the manufacturing floor. Building and deploying a downsized manufacturing test system focused on audio, GPS, or imaging simply may be a matter of repackaging and developing optimized test software, incorporating in-line automation, and providing a simplified operator graphical interface showing pass/fail analysis.
By focusing the bulk of the development time and cost upfront on open, reusable concepts and modules, telematics manufacturers are less likely to encounter late-blooming production problems and delays, which typically are far more expensive to fix in the factory than in the lab.
The cost of testing telematics continues to be an increasing concern for telematics manufacturers. As telematics becomes more sophisticated with customer-desired feature content, moving from roadside assistance services to GPS navigation to voice activation, demand for these products will grow along with the complexity of testing these systems. An open-standard telematics test system ensures that innovative telematics manufacturers will be prepared to accommodate future telematics products.
About the Authors
Joseph Veltri is a product assurance engineer at Visteon. During his career, he has been lead engineer for reliability and product-assurance testing of semiconductors and active on ESD standards committees. Mr. Veltri received a B.S. in electrical engineering from the University of Michigan and an M.B.A. from Clark University. Visteon, 16630 Southfield Rd., Allen Park, MI 48101, 313-755-8429, e-mail: [email protected].
Phil A. Williams is vice president of the global sales and strategic programs at the Acterna A.T.E. Systems Division. Mr. Williams has held senior management positions over the last 11 years with the A.T.E Division. His prior experience includes founding a technology startup company along with 28 years of combined management, sales, and systems engineering for the communications test, defense electronics, and process-control industries. 919-474-2807, e-mail: [email protected].
Paul Neal is a senior systems designer for the Acterna A.T.E. Systems Division. Previously, he was a senior test engineer at Nortel Networks. 919-474-2819, e-mail [email protected].
Acterna A.T.E. Systems Division, P.O. Box 14629, Research Triangle Park, NC 27709. Acterna was created by the merger of Wavetek Wandel Goltermann and TTC.
Published by EE-Evaluation Engineering
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March 2001