Road to the Future: Automotive photonics

The automotive world has quietly gone from low to high-tech, from blind-spot sensors to GPS to LED headlights. And despite (or perhaps because of) the turmoil the industry has recently seen, it's not just the smaller manufacturers that are getting in on the high-tech game; larger auto companies like GM and Audi are taking strides to become leaders in the field of high-tech vehicle.

Behind all this technology now tucked into vehicles is work done by optical engineers, researchers, and manufacturers working to advance the science of optics and photonics. This year's line of vehicles is no exception; cutting-edge optics and photonics technologies are making cars safer, environmentally friendly and more energy efficient.

Many large automotive companies are jumping into the electric vehicle (EV) race. BMW and Toyota both displayed their high-tech electric cars at SPIE's Optics+Photonics symposium this summer in the SPIE Photonics for a Better World pavilion. The pavilion showcased consumer-level applications of photonics technology, along with several other projects bringing energy-efficient lighting and cooking capabilities to the developing world.

"It's not often that the attendees are exposed to how this technology positively impacts their world, let alone the world in general," said Chris Karp, sales manager at Chroma Technology Corp. "The cars definitely demanded attention."

Nissan will begin selling its electric car, the LEAF, in December. Hyundai presented its first EV, the BlueOn, in September; it will roll into showrooms in 2012. Electric power is also being applied to commercial vehicles. Freightliner is the first trucking manufacturer in the country to offer drop-frame hybrid-electric beverage trucks and vans equipped with Tesla battery packs. Los Angeles County recently added a quick-charge, fully electric Proterra EcoRide BE35 bus to its fleet.

Most electric cars are being fueled by some kind of lithium-ion battery. The common perception is that using lithium is bad for the environment, but researchers at the Swiss Federal Laboratories of Material Science and Technology (Empa) conducted a life-cycle analysis of a typical electric car and found the environmental burden caused by the lithium-ion battery is at most 15% of the total impact, which includes production, maintenance, and disposal. Interestingly, 7.5% of the impact occurs when refining and manufacturing the battery's raw materials, copper and aluminum according to the report. The study found that it is primarily the operation of the electric car that has an environmental impact, exactly as is the case with conventionally fuelled automobiles. Using recycled aluminum in the manufacturing of the battery and the car reduces the impact even more.

Many drivers are still nervous about the limited range of EVs compared to standard gas engines. Rebecca Lindland, an analyst with IHS Automotive, says electric cars may not be right for everyone. "Some people are really uncomfortable with the idea that you're only going to be able to go 100 miles round trip," says Lindland. "The typical car has a 300-mile range. That's what people are used to."

For most people, however, electric cars provide more than enough get-away power. Data from Pike Research's Electric Vehicle Consumer Survey showed that 73% of drivers of gas vehicles use their cars for 30 miles or less per day, estimated to be a work commute plus and errand or two. Other surveys have concluded that a reduced range of 70 miles would be sufficient for most drivers. This means electric cars would suit the needs of 95% of North American drivers, according to a recent survey conducted by Nissan. Now, drivers will have to learn to plug in their vehicles before they go to bed at night or while they are at work.

Photonics continues to make its mark in the automotive industry with new headlights based on light-emitting diodes (LEDs) and high-intensity discharge (HID) technology. Because LEDs headlights are made using an array of LEDs, this allows for creativity in the design, color, and shape of the vehicle's exterior lights. Auto designers are using this capability to integrate the lights more cohesively with a car's design and branding.

LEDs have been for used for years in automotives on non-headlight applications, including interior lights, turn signals and brake lights. But now, headlights that use an array of LEDs appear on vehicles such as the Cadillac Escalade, MINI, Mercedes-Benz R Class and SLS E-Cell, and the new Audi A8.

"The overall system cost hurdle is often still too high to offer a LED-based solution as the standard entry-level solution," says Steve Landau, director of Marketing Communications, Philips Lumileds Lighting Company. "However as total LED system performance increases rapidly due to technology advancement, more intelligent engineering solutions and cost-effective, mature supply chains, system costs are decreasing accordingly and a broader range of applications becomes available for a viable, economic use of a LED-based solution."

According to a market report by Automotive Designline Europe, LEDs have come down in price from about $5 a few years ago to under $1 in the last 12 months, and are expected to continue to lower their price dramatically over the next year.

As another perk, LED headlights are about 95% more efficient than halogen, says Jonathan Dunlap, Sylvania product marketing manager. More energy-efficient headlights may be particularly critical for EVs and EV hybrids. To conserve energy, the 2010 Toyota Prius hybrid uses LED low beams so owners can drive farther at night on a single charge, according to Jonathan Dunlap, a Sylvania product marketing manager.

LED headlights also have a longer life in comparison to halogen and HID. The average lifetime of a halogen headlight is about 1,000 hours, while an HID headlight lasts about 3,000 to 4,000 hours, says Dunlap. An LED headlight lasts more than 6,000 hours, the lifetime of the average automobile.They also lower a car's overall carbon footprint: A 2008 study by the University of Michigan's Transportation Research Institute found that a 100% LED lighting system in a car resulted in light power savings of over 50%, saving gas and reducing the vehicle's total carbon footprint by 1% to 2% per year.

"The two-wheeler and truck market are good examples where the value of LED lighting can pay off fast and accelerate LED adoption across industry," says Landau.

Besides energy efficiency, a top priority in the automotive industry today is passenger safety. Photonics has enabled driver-assistance systems such as antilock brakes, cruise control, tire pressure, blind-spot detection, intelligent parking and lane-departure warning systems, and night vision to be effectively integrated into vehicles.

Many car companies and industry watchers are predicting that sensing and safety is where photonics will see the largest applications in the automotive industry. Angle and motion sensors are already widely used in vehicles for applications such as pedal position-sensing, throttle control, and in transmissions and steering wheels.

"Today's state-of-the-art vehicle is equipped with a large number of sensors, up to 100 sensors or even more," says Jiri Marek, senior vice president engineering sensors at Bosch, Germany. "MEMS sensors are a key component for state-of-the-art engine management systems and other drive train applications and therefore play an important role in the improvement of fuel efficiency and emission control," says Marek.

New safety regulations in Europe and the United States are driving car manufacturers to include more Microelectromechanical System (MEMS) sensors in their vehicles, for vehicle dynamics management, tire pressure, engine performance, manifold air pressure and barometric air pressure management, and emergency stop-start systems. iSuppli predicts that the market for MEMS automotive sensors will see a huge rebound by the end of 2010. They project global shipments of MEMs to reach 591.2 million units in 2010, up a resounding 17.8 percent from last year.

Hella partnered with Samsung and developed a smaller, lighter-weight rear-view camera for cars and trucks of all types that is small enough to be integrated into any vehicle. Hella also created a camera-based light system for Mercedes E-class models that automatically adjusts the brightness of the car's beams based on the location of any oncoming vehicles.

Martin Fischer, president of Hella Electronics and the Hella Corporate Center USA, said in a press release, "Based on the interest we've received from automakers, we plan to have our new camera in production by 2011, just in time to meet requirements of the Kids and Cars Safety Act (H.R. 1216)."

BMW's new 5-series includes several photonics-driven features: rain-sensing wipers, power-heated mirrors, and a dual-zone climate control system, reverse-sensing sonar, and auto-dimming rearview mirror.

Light manufacturers are developing headlights that automatically provide more light farther in front of the vehicle when it reaches a certain speed.

With the introduction of EVs and other electronic devices like smart meters and computers, there is concern that this will overburden the already ailing U.S. power grid. Not to worry, according to Sunil Chhaya, senior project manager at the nonprofit Electric Power Research Institute. "We have plenty of capacity if we use it right," he says. "But we have to plan."

The number of vehicles that plug into the electrical grid will be relatively small during the next few years and will not require building additional power plants. But their potential impact in drawing power from residential neighborhoods at peak times will necessitate establishing communications with the grid. The Electric Reliability Council of Texas, which operates the state's power grid, is studying the effect of plug-in hybrids and electric cars. They have said they are determining the best times to charge electric cars as well as changes needed to integrate them.

EVs will be among the most connected vehicles available, receiving information about where to charge, and when they plug in, exchanging information with the grid so that they can be charged best. However, the pathway and role each type of equipment plays has not yet been decided by any of the equipment manufacturers. One idea is for residential charging equipment to useexisting communications such as the local wireless or broadband connection, relying on commercial cellular networks, or by plugging into a smart meter where available.

Once smart grid equipment is in place, EVs will provide information about how much energy they'll need, and the grid can automatically determine when and at what rates the vehicles will be charged.

Research firm Supplier Business released a study saying that integration of this kind of technology is increasing at a rapid pace, in part because of the adoption of smartphones and similar devices.

"In contrast with earlier Telematics times, 99% of car owners already have cell phones; 22% have smart phones and this is forecasted to rise to over 50% in North America by 2013," says the report.

iSuppli also reports that Bluetooth or other handless phone technologies are available equipment in 93% of model year 2010 vehicles in the U.S., and 75% of models in Western Europe. IBM Research forecasts that the production of vehicles fitted with telematics will grow from 9% in 2009 to 46% in 2017.

The next versions of the Nissan Leaf and Chevrolet Volt to hit the market will both include cellular connections in the vehicle.

Dave Proefke, Buick inventor and GM Technical Fellow, recently told USA Today about GM's plan to have the Chevy Volt and the Chevy Cruze come with purchasable smartphone apps that let owners do things like unlock the car, start it remotely, or honk the horns if they need to find the car in a crowded parking lot.

The radio waves are also encrypted and change themselves frequently so there's little worry of someone using this app to steal your car. On the other hand, you would have to worry about leaving your phone in the car.

Beth Kelley is a science and technology writer.