Electronic Design
Cars Need System Synergy

Cars Need System Synergy

Electronics has radically transformed the average modern automobile compared to even the most advanced auto designed two decades ago. However, increasing complexity and costs have challenged carmakers and their tier one suppliers, especially in the average and low-end categories.

Systems that address vehicle controls in powertrain, safety & security, chassis & suspension, and body electronics as well as rapidly changing infotainment and telematics systems need to mesh seamlessly to achieve system synergy. Without this design strategy, time-to-market and costs will increase unnecessarily and consumers’ perception of value will not be optimized.

SYNERGY IN THE MARKET
The philosophy of system synergy, while similar to previous approaches used to design and define complex systems, is rather recent. In fact, it isn’t a current buzzword in the industry, but perhaps it will become one. Toyota calls its combined internal combustion and electric powertrains the Hybrid Synergy Drive, which demonstrates the concept.

The telltale signs of system synergy are easily observed, and there are many reasons to embrace the methodology. Terminology used to identify system synergy includes sharing, seamless integration, compatibility, adaptation, leveraging, concurrent, ecosystem, and reconfigurable. System synergy includes all of these concepts and more. Synergistic design is important, and many of the reasons for increasing system synergy have overlapping benefits (see the table).

One of the most recent examples of system synergy is the relationship of emerging electric and plug-in hybrid powertrain systems with infotainment and telematics systems. Electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) must interface with the power grid. To obtain the maximum electric driving range, companies that have introduced these vehicles also have introduced applications for monitoring the charge status of the vehicle, so drivers can remotely monitor and even communicate with the vehicle over a smart phone.

Beyond checking the vehicle’s charge status, remote communications can initiate charging, preheat or pre-cool the interior while connected to the power grid, and more. These actions can reduce range anxiety (the fear of running out of electrical energy) in the EV or extend the PHEV’s range in the pure electric mode.

Vehicles with electric propulsion have necessitated changes in other systems as well. The energy-saving engine start/stop feature in micro hybrids as well as hybrid electric vehicles (HEVs) can cause supply voltage issues for on-board electrical equipment. STMicroelectronics’ TDA7850LV power amplifier addresses power quality issues in the audio system.

Telematics and navigation play a major role in synergizing traffic data and eco-conscious navigation and driving. For EVs, telematics are critical to identifying and staying within range of the next charging station, including modifying the driver’s style from aggressive to conservative.

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Besides the addition of electric propulsion, there are compelling reasons for system synergy to occur now. “The amount of electronics is just exploding in vehicles and the opportunity to leverage our electronics and our software in multiple places, even in a single vehicle, is becoming very popular,” explains Andrew Poliak, director of automotive business development for QNX Software Systems. The most obvious applications are right in front of the driver—the dashboard displays.

INSTRUMENT CLUSTER & CENTER STACK
Dashboard synergy is occurring in many areas in the vehicle. Information can be presented in the instrument cluster or displayed in the center stack, on a heads-up display, or even to passengers in the rear seat. In addition to the displays, behind the scenes technologies include the operating system (OS), processing, and filtering. In general, the way information is displayed to the driver is undergoing a major transition.

“It’s no longer being a cluster and a center stack and nav system. You’re seeing these very broad displays, called cockpit displays,” says Poliak.

John Bridwell, director of applications for the Automotive Business Unit at Renesas Electronics America, agrees. “Generally speaking, we see that infotainment and telematics have become one,” he says. “To take that a step further, we are starting to see that merge into the overall cockpit-type solution.”

At the recent 2011 International CES in Las Vegas, automakers and suppliers brought out their latest products, and the synergy was an evident part of many. In their keynote presentation, Ford Motor Company representatives identified several areas. In the Ford Focus Electric (Fig. 1), the dash displays information on the left and right of the driver’s information system and on the center stack display.

“When I shut down, all three screens come to life to tell me something about my drive,” says Amy Garber, manager of electric-vehicle electronics at Ford. “The electric-vehicle content built into MyFord Touch provides owners with as much or as little information as they want—and it’s customizable and personalized.”

Also at the 2011 International CES, Audi AG showed a concept of center stack, driver instrumentation, and heads-up display sharing information to various degrees. As Audi AG Board of Management chairman Rupert Stadler observed in his keynote address, “While drivers seek great information, drivers need functional integration.”

The newest displays with increased functionality have increased the requirements for graphics processors. “The overall graphics capability in the car is just growing tremendously,” says Tom Siegel, applications engineering manager for the Automotive Business Unit of Renesas Electronics America Inc. Graphics requirements are basically doubling because of the combination of infotainment and 3D graphics. “It’s literally twice the processing power required,” says Siegel.

QNX operating systems and software are used in reconfigurable instrument clusters like the Visteon units in the Jaguar and Land Rover. According to QNX’s Poliak, one vehicle that will be launched this year will have three different devices from two different suppliers. “There’s a digital reconfigurable cluster, a center stack display, and a radio and they’re built by two different tier ones all using QNX’s OS,” he says. The data for the three systems is displayed in different places.

QNX’s OS (Fig. 2) has a microkernel that provides reliability and other functionality. “When you combine two microkernels over a network, they can share resources as if they are local,” says Poliak. “This becomes really interesting for things like cameras for applications for sharing of resources transparently.”

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For high-end vehicles, the sharing of displays for multiple systems is nothing new. Bill Boldt, senior business development manager for Signal Path Products at Fairchild Semiconductor, has active video filter drivers (FMS6141/FMS6151/FMS6143) that have been used in merged applications for many years.

“What they were doing was putting navigation systems, back-up cameras, and DVD screens into cars,” says Boldt. “What’s happening now, it is accelerating due to smart phones.”

The single-channel (three-channel in the FMS6143), 8-MHz (standard definition), fourth-order filters in the FMS6141 (fifth order in the FMS6151) replace passive LC filters and provide 6-dB gain as well as improved image quality compared to second- and third-order passive solutions for these displays.

Some combinations and sharing will not occur without resolving some potential problems. “When you talk about infotainment and dashboard merging into this cockpit theme, you really have a merging of two different worlds from the standpoint of safety-critical,” says Nathan John, platform solutions manager for the Automotive Business Unit of Renesas Electronics America Inc.

There are issues for operating systems focused toward safety-critical applications versus infotainment applications. It’s just one of the challenges that stands in the way, explains John, along with the issue of driver distraction.

To cope with the increased requirement for processing power, Renesas solutions include multiprocessing and multicore architectures, focusing on ARM Cortex A-9 processors.

“We are adding some video and sound processing units that offload those codex requirements from the main cores so that the customer has more processing power to do things for other functionality,” says Renesas’ Bridwell. “The sound processing allows parallel processing so the ARM core can focus on the application-intense type solutions.”

Visteon is incorporating a Renesas microprocessor in its next-generation multi-function display (MFD) platform architecture. The MFDs will provide a range of information to drivers, either as standalone displays or in combination with radios, navigation devices, and external cameras. Visteon credits the processor and its higher level of integration with reducing components and complexity, decreasing in design and engineering time.

REARVIEW CAMERAS
To enhance rear visibility, the National Highway Traffic Safety Administration (NHTSA) has proposed amending federal motor vehicle safety standards to require a rearview camera. Estimates put the cost of adding the rearview camera equipment between $88 and $158 on vehicles that already have a display screen and from $159 to $203 for those that have to add the display.

The navigation display makes an ideal candidate for displaying the back-up camera information, according to Rick Kreifeldt, vice president of global automotive research and innovation in the Corporate Technology Group of Harman. “We have a solution that does object tracking when you are backing up,” says Kreifeldt. “It can run on a very inexpensive microprocessor because we shut off the navigation.” Harman can leverage the microprocessor power because navigation information isn’t required when the vehicle is backing up.

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Other suppliers have different locations for displaying the rearview camera image that are synergistic with their products. One possibility is in a reconfigurable instrument cluster. “When you put the car in reverse, you don’t need the tach, so instead show the back-up camera,” suggests QNX’s Poliak.

Some suppliers see a better match for a low-cost camera display through the rearview mirror. For example, Azentek SmartMirror is an aftermarket rearview mirror with GPS navigation and the option to include a license plate-mounted backup camera. Gentek also offers rearview mirrors that can display the information from the back-up camera (Fig. 3).

WARNING PEDESTRIANS
The lack of engine noise for EVs as well as HEVs and PHEVs operating in the electric mode poses problems for pedestrians. As a result, a bill passed earlier this year directs the Secretary of Transportation to study and establish a motor vehicle safety standard to provide a means of alerting blind and other pedestrians of motor vehicle operation. Carmakers and suppliers are already addressing this issue.

In addition to the passenger compartment audio systems it has supplied to several carmakers, Harman has developed acoustic technology for electric and hybrid vehicles with Lotus Engineering. The HALOsonic system produces authentic external engine sounds that warn pedestrians and cyclists that the hybrid or electric vehicle is approaching when it’s running in the almost silent mode.

Building on Harman’s highly efficient audio design capability, the system uses two high-efficiency speakers specially developed for the exterior of the car to play back the dynamic engine sounds generated by a special algorithm. In addition to the external warning, the synthesized sounds provide a familiar audio link for drivers and passengers.

Reducing the power consumption can provide synergy between any system and the charging system, especially in EVs and PHEVs to maximize driving range. This has occurred as carmakers have moved to Class D audio. It has also given a head start to a semiconductor solution for pedestrian warning.

“They didn’t have a problem with class AB,” says Ryan Reynolds, manager of system engineering and product marketing for mixed-signal automotive audio at Texas Instruments. “They just wanted it to be higher efficiency.” The reduced power can improve fuel economy while reducing generated heat, emissions, and the battery’s energy drop.

TI’s TAS5414 and TAS5424 four-channel digital audio amplifiers are designed for use in automotive head units and external amplifier modules. The digital pulse-width modulation (PWM) operation provides significant efficiency improvements over traditional linear amplifier solutions.

To meet the proposed EV audio warning for pedestrians, TI’s automotive customers have asked the company to modify the four-channel audio amplifiers. “For the warning system, they really don’t need that,” says Reynolds. “They need two—one for the left side of the car and one for the right.”

As a result, TI is going to build a two-channel part. For the warning environment, other changes will make operation easier. But the basis of the new product is the existing audio amplifier design used for entertainment. It’s an established, automotive-approved technology for entertainment, and now TI is taking it to a new application.

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LIFESTYLE SYNERGY
In addition to its systems, a vehicle must have synergy with its driver and the driver’s lifestyle. This could help define new functionality. For example, Ford announced that its soon-to-be introduced C-MAX multi-activity vehicle will have the company’s and perhaps the industry’s first hands-free liftgate (rear cargo door). The intent is to help drivers open the liftgate when their hands are full.

The system detects the combination of an RF key fob and leg motion to unlock and open the liftgate and safeguards against any accidental opening. It uses two capacitive sensors (Fig. 4) located behind the fascia in the bumper to detect the proximity of a leg and leg motion.

“It’s looking for a conductor, in this case the human leg, and then it’s looking for a certain proximity and some degree of motion that goes along with it to activate the liftgate,” says John Davis, chief program engineer for the C-MAX, Ford Motor Company. While capacitive sensing is an integral part of touch-sensitive displays used by Ford, “the technology is unique in terms of this type of application,” says Davis.

“You obviously have to have the vehicle enabled with the two critical technologies that include our intelligent pushbutton start system and a power liftgate system,” says Davis. “The real technology add are the control module and the two sensors,” he says.

SOFTWARE FOR SYSTEM SYNERGY
How do carmakers and suppliers know when they have good system synergy? In the simplest situations, most of the components were already on the parts list. If software is the added factor, a high degree of synergy exists.

This is the case in Ford’s Curve Control Technology (CCT), a standard feature on the 2011 Ford Explorer that also will be available on the Ford C-MAX. The CCT system can correct over-steer or under-steer without driver intervention.

The system uses existing roll rate, yaw rate, lateral acceleration, wheel speed, and steering wheel angle sensors in the Roll Stability Control system. The algorithm was the enabler for the new feature, says Ford’s Davis. Ford’s Roll Stability Control system already combines braking and engine control with additional sensors.

Sensor fusion is increasingly being used in vehicles to combine the information from two or more sensors to obtain better results than could be obtained by the sensors operating independently (see “OEMs Save Costs And Space By Sharing Sensors”). Infineon sees sensor and data fusion as an important part of increased system synergy (Fig. 5).

“The computing power and the integration of these modules into that final blue box on the right takes a lot engineering, a lot of smarts, and it may take a lot of cost out of the car while providing additional functionality,” says John McGowan, director of safety electronics for Infineon North America.

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