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August 17, 1998

In-car computing gets personal

Having conquered the office and home, PCs are invading your other daily environment, the car. PC and chip vendors want to enrich the driving experience by integrating open-architecture computing into automotive electronics.

Stephen Kempainen, Technical Editor

In a few years, you will pick not only the color of your new car, but also the amount of RAM and the size of the displays for your in-vehicle computer. PC technology joins the throng of automotive electronics aiming to improve safety, performance, and communications. PC- and automotive-industry giants are trying to integrate automotive electronics and computers into a cohesive architecture that allows buyers to personalize their cars with gadgets and software.

The trend toward personalizing the auto with an in-car computer provides enticing opportunities for entrepreneurs and designers to bring add-on peripherals and application software to market. Furthermore, the combined automotive- and PC-industry volumes will allow low-cost products to migrate to embedded designs that benefit from the rugged specifications of automobile equipment.

Evidence of the driver-information-systems trend comes from automotive manufacturers that report significant demand for office electronics in new cars. It seems that many drivers want to make their time behind the wheel productive. The result is a surge of luxury cars equipped with office appliances, such as mobile phones, fax machines, and modems. A product taking this trend to the extreme is the mobile office—complete with a computer, printer, and combination desk/filing compartment—which straps into any front passenger seat. Besides office electronics, the after-market sales are picking up for games, TVs, and digital-versatile-disk (DVD) players. For example, forecasters predict that Japanese drivers will purchase more than 3 million Global Positioning System (GPS) navigation systems this year.

More electronics in the car improves the driving experience; however, clutter and a limited number of cigarette lighters available as power outlets can create unsafe conditions. Another problem resulting from adding electronic products is the existence of duplicate functions, such as wireless data connections in both personal digital assistants and trouble-monitoring emergency-alert systems. Other examples are displays and processors in both the navigation system and the DVD player.

Instead of duplicating electronic functions, it makes sense to reuse the wireless connection, processor, and display for multiple applications, thereby reducing power and clutter. Other benefits of integrating these products into a system are increased safety, security, productivity, and entertainment. Several initiatives by electronic and automotive companies aim at standardizing the hardware and software interfaces to promote the benefits of many applications using the same displays, wireless communications, and power supplies.

A PC is only one item on the list of electronics that manufacturers are adding with each new car-model year. Today's cars are full of electronic features for safety, control, and comfort. Safety-critical features, such as active suspension and antilock-braking systems, are recent additions, and brake by wire and electronic steering are coming soon. These mission-critical functions attach to fault-tolerant buses, such as the J1850 and controller-area-network (CAN) bus (see "CAN protocol eases automotive-electronics networking," pg 95). Maintaining the separation of these fault-tolerant buses from the open-electronics bus is mandatory because you do not want a PC's operating-system general-fault condition to affect your car's engine control.

However, information on the automotive-specific electronic bus is valuable for driver-information-system applications. Remote diagnostics, collision-avoidance warning systems, and performance monitoring are some applications that rely on data from the automotive bus. The automobile needs a gateway to isolate the automotive-specific bus from the open-electronics bus. Thus, the Society of Automotive Engineers (SAE, www.sae.org) envisions a way to facilitate these applications with a comprehensive set of standards, which includes an open, low-speed electronics bus and a gateway that protects the fault-tolerant bus from the in-car-electronics bus. This gateway still allows useful power-train and body data to transfer to the electronics bus (Figure 1). This month, the SAE will finalize the standard for the low-cost Intelligent Transportation Systems Data Bus (IDB). The IDB performs 115-kbps data transfers in a peer-to-peer bus architecture. Many automakers support the bus, and after-market products should begin to appear in late 1999.

The SAE is also working with Ertico Intelligent Transport Systems Europe (www.ertico.com) on standardizing an in-car multimedia bus. The Ertico working group is considering proposals for a high-speed bus that accommodates audio, video, and wireless data. Proposals for the high-speed bus include the IEEE 1394 and the Multi-Media Link from Delco (www.delco.com), both of which transfer data at 100 Mbps. Other proposals include the D2B (Domestic Digital Bus) Optical bus for 11.2-Mbps transfers and the Media Oriented Systems Transport (MOST) from Oasis SiliconSystems. The SAE standards are only the beginning of proposals for integrated in-car computing.

Giants in the driver's seat

Complementing its support for the SAE standards, Motorola is promoting AutoPilot, a flexible, modular, open architecture. AutoPilot takes an embedded-system approach to in-vehicle computing that supports multiple products for a range of features and prices in a common platform. Motorola bases AutoPilot on the PowerPAQreference design (www.mot.com/powerpaq) that is free on the Web. The PowerPAQ mobile-computing platform integrates a variety of technologies, including GPS, paging, flat-panel displays, automotive-bus interfaces, the IDB, wireless communications, and digital car radios. The hardware supports many real-time operating systems. A variety of software applications for navigation, autodiagnostic, speech, and productivity tools is also available.

PC giants Intel and Microsoft are collaborating but still promoting separate initiatives, because they see in-vehicle computing as one of the next strategic locations for their products. Intel is promoting its initiative for the Connected Car PC technology. The Connected Car PC is a collection of mature technologies, including GPS, digital wireless communications, radio data broadcast, Universal Serial Bus (USB), and automatic speech recognition, which uses the Pentium processor to provide an assortment of in-vehicle applications. The applications include navigation, entertainment, communication, information, and security. The Intel Connected Car PC requires a full-blown PC using the Windows 98 operating system, and after-market products will be available in 1999.

Intel expects the Connected Car PC technology to offer travelers the full consumer PC experience and points to the notebook PC as a design reference upon which to begin building the technology. This scenario requires a µP, a chip set, memory, and I/O devices at a minimum. Input and output are through modern interfaces, such as USB and 1394, rather than legacy interfaces. A connection through a gateway to the cars' automotive digital buses, such as CAN and J1850, allows monitoring of onboard electronics and mechanical systems for problems and troubleshooting. Intel is working with companies that produce stand-alone technologies for these applications to integrate them into the Intel Architecture Connected Car PC.

An example development platform for Connected Car PC products is the RadiSys EPC-43 fully configured, embedded multimedia PC. RadiSys sees the Connected Car PC technology spawning a variety of special-purpose embedded-computing applications for over-the-road trucks; construction equipment; taxicabs; and delivery, emergency, and public-service vehicles. RadiSys is working on an in-vehicle reference design for prototyping, field trials, and application development. Other companies working on Connected Car PC technology include ComRoad, Dearborn Group, Kontron Electronik, SiRF, and Mitac.

The other PC giant, Microsoft, is promoting the Auto PC platform for in-vehicle computing. This platform uses the Windows CE operating system and recommends a minimum hardware specification. The Auto PC hardware includes a 60-MIPS or higher CPU; a minimum of 8 Mbytes of RAM; a 256X64-pixel with 3-bit color display; and a CD-ROM drive for data, program, and music discs. Microsoft also recommends the USB and a serial port for optional peripherals, CompactFlash slot memory, and an IrDA port. Other optional hardware includes a GPS receiver and mobile-phone docking cradle. Even with all this hardware, the Auto PC fits into the same dashboard space as the car radio and CD player.

For about $1000 for the basic unit, you can get applications for an address book, for driving directions and navigation, and for an advanced radio and CD player, all of which you can control with speaker-independent speech recognition. A color display and a speech synthesizer provide the outputs in response either to your voice or to button and numeric keypad commands. Microsoft expects many third-party applications, such as cellular-phone integration, wireless data, and information systems, to appear soon. However, the Auto PC platform appears to lack a strategy for accessing the automotive bus to make use of power-train and body-electronics data. Typical after-market car-radio companies, such as Clarion (www.autopc.com), will manufacture the Auto PC, and products should appear in retail electronics stores this fall.

The initiatives from Motorola, Intel, and Microsoft all have qualified support from the OEM automakers. Automakers, concerned about liability, want to get in-car computing right and think they must proceed at their own pace. Their pace may be closer to Motorola's "Personalizing the Driving Experience" initiative, which gradually integrates PC technology, unlike Intel's approach, which shoehorns a notebook into a car. Whatever architecture in-car computing converges on, designers and developers must understand the safety, reliability, and performance-design issues for the automotive environment.

When integrating state-of-the-art computer electronics into an automobile, you must consider safety, reliability, and performance. Safe operation of the vehicle is the primary issue; electronics mustn't distract the driver's eyes and mind from the road. Reliability and performance concerns include power-supply variations and EMI, which are inherent to the automotive electrical system and often need attention. Also important to reliability and performance are the extreme temperature, humidity, shock, and vibration environments in which cars operate. In-car electronics should perform reliably at -40 to +80°C, with high humidity, over speed bumps, and with the constant vibrations of rough roads.

None of these issues are new to automotive electronics. Designers have successfully dealt with the safety, environmental, and power-supply issues in a well-known automotive-electronic product that serves as a model for in-car computing: the car radio. The radio is safe because it is easy to operate with little distraction from driving. Radios also provide state-of-the-art audio electronics in cars with design cycles much longer than those of the radios and serve as an example of how complex electronics can survive in the rugged environmental and power-supply conditions of cars (see sidebar "Up-to-date automotive electronics").

Safe cyber-surfing while driving

Safely operating sophisticated electronics while driving is a bigger concern to automakers than is development-cycle disparity. Over the years, concern about safely operating car radios has led to features such as pushbutton channel selection and controls on the steering wheel that allow drivers to keep their focus on traffic. However, automakers point to the problems that mobile-phone operation causes. So far, seven countries have banned mobile-phone use in moving vehicles.

Some in the insurance industry claim that mobile phones are second only to intoxicated drivers as the leading cause of automotive accidents. Why is talking on the phone more hazardous than talking to a passenger in the vehicle? It could be that a passenger in the vehicle is also concerned with the safe operation of the vehicle, whereas an absent person cannot alert the driver to traffic conditions. Whatever the case, automobile OEMs are wary of introducing a man-machine interface that could distract the driver with sounds, displays, or absent people.

A safe man-machine interface becomes the critical design issue for introducing computers into vehicles. In-car-computing initiatives rely on technologies such as automatic speech recognition, at-a-glance graphical user interfaces, and automatic disabling of visual entertainment programs to reduce driver distraction and maintain safe vehicle operation.

Natural-language speech recognition allows drivers to keep their eyes on the road and hands on the wheel. Speech control of electronics is an important part of in-car-computing initiatives, although some statistics indicate hands-free mobile-phone use does not improve safety. Both the Auto PC and Connected Car PC initiatives include speech-recognition and text-to-speech technologies. Motorola's vision for personalized in-car computing includes a scalable-language application-programming interface (API, www.mot.com/slapi) that allows developers to add speech-recognition and text-to-speech programs to their applications. The scalable-language API applies to a variety of operating systems for Motorola's MPC8xx processing platforms.

The Auto PC and Connected Car PC initiatives both use speech technology from Lernout & Hauspie. The company's technology is compatible with the speech API in Windows operating systems. With the Lernout & Hauspie ASR200 speech-recognition engine, drivers can control climate systems, lighting, security, the radio, the CD player, and computer menus. The ASR200 provides noise-robust, speaker-independent, and speech-at-a-distance recognition in multiple languages and allows any embedded application to recognize and respond to spoken commands without training. The Lernout & Hauspie text-to-speech technology allows applications to generate speech from text with support for multiple languages and intelligent text processing.

At-a-glance displays

Speech technology is an important addition to the man-machine interface but does not replace a well-designed graphical user interface and display. The display also serves "infotainment" applications, such as DVD and TV. Displays in cars must be lightweight, must conserve space, and must be easy to see in all lighting conditions and at all viewing angles. In addition, the display should be inexpensive and insensitive to temperature and vibration. These design criteria pose big obstacles for CRT and LCD technologies.

CRTs are too bulky and expensive, and LCDs have problems with temperature and viewability. LCDs, with 6-in.-diagonal, 640X480-pixel displays are the popular choice for automotive-navigation systems. However, the viewing angle can adversely affect brightness, contrast, and color. In addition, LCDs require heating elements to work at below-freezing temperatures, and the display becomes wobbly at high temperatures. Automotive applications need displays with the clarity of CRTs and the size of LCDs.

A new display technology that fits these requirements is the field-emission display (FED). FEDs use less power and are more rugged than CRTs or LCDs. Furthermore, FEDs operate over the industrial-temperature range, and you can easily view them in a range of lighting conditions. FEDs are instantly on at temperatures below freezing, and the viewing angle has no effect on brightness and color.

Like LCDs, FEDs are flat and lightweight. Two plates of glass, separated by a 1-mm vacuum, serve as the cathode and anode. The back silicon glass is the cathode and has hundreds of tiny tips in each pixel region. The tips source electrons that accelerate across the vacuum toward the front glass. Standard CRT phosphors coat the front-glass anode and emit the full spectrum of colors when the electrons from the cathode bombard the phosphors. The resulting picture is bright, crisp, and viewable from a 160° angle.

FED demonstration kits should be available from Motorola's Flat Panel Display Division during the third quarter of this year. The kit will include either a 2.9-in.-diagonal display with a resolution of 128X160 pixels or a 5.6-in.-diagonal display with a 320X240-pixel QVGA resolution. The displays feature a brightness level of 350 cd/m² and a 100-to-1 contrast ratio. The 2.9-in. display has 3-bit (512) colors and about 0.5W power consumption when 15% of the pixels are illuminated. The 5.6-in. display has 262,000 colors and consumes about 2W when 15% of the pixels are illuminated. However, both devices currently operate only at 0 to 50°C, and the promised -40 to +85°C devices are still under development. Motorola expects prices to compete with those of LCDs when the technology matures but sells them now for a premium because of the benefits of FEDs over LCDs.

EMI and power transients

After ensuring a safe man-machine interface, the next big concern is maintaining the reliability of the electronics in the rugged car environment. "Rugged" refers to such things as the automotive power supply, which has power rails with voltage spikes greater than 100V and intermittent loss of power. Power-regulation devices, diodes, and fuses can protect electronics from these conditions. To save space and cost, power-supply conditioning should be in one location, and all digital electronics should share this location.

EMI is a tricky issue because fields that power transients create inundate the vehicle and can couple onto digital data buses. Routing data buses away from alternators, motors, and wiring harnesses that may carry transients is critical. However, the ultimate solution to EMI problems is implementing plastic optical-fiber buses. Low-cost plastic fiber eliminates the danger of electrical transients coupling onto a data bus and damaging data or electronics. In addition, the fiber is lighter than the copper alternative and is unaffected by humidity and oxidation.

Plastic-fiber buses provide many other advantages in the rugged automotive environment. Besides being lightweight, providing space savings, and offering immunity to EMI, fiber also provides a system with high intrinsic bandwidth. For example, the D2B works in automotive networking applications. The D2B has 11.2-Mbps bandwidth and can transfer audio and video data. Optical connectors for the D2B can fit into many applications. Amp supplies complete D2B connector systems, which include a light source and detector, which mount in a header, and the fiber-optic cable assemblies.

The last design considerations are the extreme temperature, humidity, shock, and vibration that cars encounter. All electronics under the hood and most others in a car must meet the -40 to +85° operating range. Shock and vibration design goals depend on the vehicle's intended use; for example, whether the driver uses the vehicle for off-road, 4X4 driving or for construction or farming tasks. Improvements in mechanical mounting have solved problems with rotating media, such as CD players.

OEM-product assurance

Automakers are enthusiastic about incorporating PC technology into their products, but they still have reservations; they must first fully explore the business, standardization, maintenance, and connectivity issues. Because automakers know that car buyers will not tolerate frequent maintenance problems or even the occasional need to reboot a computer system due to software incompatibilities, the automakers must address these issues. Any electronic products integrated into a car must be reliable and long-lasting in rugged automotive surroundings.

The human-safety factor is still the most important issue and the biggest unknown. Questions remain as to whether voice-recognition systems will really enable a driver to undertake multiple tasks and still focus on the road. Drivers can process only a finite amount of information before they lose focus on their responsibility to the safety of passengers and other drivers. So, even if PCs in cars turn out to be no more than babysitters for bored passengers, a big market for that service could emerge.

Up-to-date automotive electronics

By using the car radio as a model for in-car computing, you can see how car OEMs offer state-of-the-art electronic options in new-model cars that they designed at least three years ago. Car radios personalize vehicles by providing the buyer with many options from which to choose. Ford (www.ford.com) offers 40 radios to help differentiate Town Cars from Escorts and from the competitors. You can choose from low-end economy models to high-end sound systems complete with bells and whistles. Or you can forgo a factory-installed radio and go to the after-market for a much wider selection of radios, all of which fit into the same dashboard slot without much trouble.

The after-market radio is also a good example of how to get the state-of-the-art electronics into a vehicle that OEMs designed years ago. Because of the difference in the development cycle of new model cars (three to five years) and of the typical electronics development cycle of six to 12 months, buying a new car means getting legacy electronics. The disparity between vehicle design cycle and the computer and consumer-electronic design cycle is getting smaller but will never disappear entirely. Because of the time devoted to extensive safety testing and retooling of plants, vehicle design cycles will never match the computer industry's cycle.

In-car-computer architectures need to account for the disparity in design cycles. Fashioning a PC and consumer/automotive-electronics architecture similar to the car-radio model can resolve out-of-date electronics problems; automakers and electronics developers can decouple the development cycles. Therefore, the after-market for computer, communications, and consumer electronics would flourish independently of the vehicle-development cycle by allowing new electronics to fit easily into a car that was designed years ago. However, the industry has yet to reach a consensus on an efficient and technically feasible standard approach for plugging any electronic manufacturer's product into any vehicle's computer bus.

Reference

1. Kempainen, Stephen, "Automatic speech recognition lets machines listen and comprehend," EDN, March 3, 1997, pg 73.

Stephen Kempainen, Technical Editor

You can reach Technical Editor Stephen Kempainen at 1-415-643-1760, fax 1-415-643-9513, ednkempainen@worldnet.att.net.

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