The freeway you drive everyday suddenly slims down one lane because of an accident—how frustrating. The cars in that blocked lane have to move over. So they inevitably cause a slowdown in traffic in all the other lanes. But is that slowdown really inevitable?
The German government is sponsoring an auto industry initiative called “ACTIV,” intended to spur use of technology for traffic management and lead eventually to automatic guidance. As one of its contributions, Volkswagen’s engineers produced a study that shows how to free up traffic snarls by having cars speed up at exactly the right time. It’s basically what you’ve always wished drivers would do: speed up and let the other drivers in.
Here’s how it would work: Instead of letting all cars slow down in the traffic flow, a car in the lane adjacent to the closed lane would be instructed to speed up just before reaching the snarl. That would create a space behind it for a car in the blocked lane—without coming to a near stop and trying to edge in at the last minute. A traffic management system, tricked out with cameras and computers to record and analyze the road, would provide instructions on when to stop and go.
A more effective system would assume semi-autonomous control of the vehicles approaching the bottleneck. This could be used with an advanced version of adaptive cruise control and interactive communication to a local traffic management system. The reality, of course, is that without fully automated highways, there’s not much that can be done about a rubberneck at the site of an accident.
The active steering control system on this experimental Volkswagen uses on-board cameras to read lane markings and kept the test vehicle in lane, even on curves at highway speeds.Drowsy driving is a major cause of accidents around the world. Soon, sophisticated camera systems will be able to read highway markings and sound a gentle warning to alert the driver if the vehicle is drifting. But even more aggressive intervention is in development, and Volkswagen showed us a car that was able to correct its own path in such a scenario.
At the Volkswagen proving grounds in Germany, we tested the system at moderate highway speeds. We didn’t exactly fold both arms into our lap and forget about driving—it is rather tough to trust a computer with your life—but it did work quite well. Here’s how: Thanks to electric power steering, a computer can control the steering gear motor signaled by a camera system and another computer judging the situation. If the camera and sensors detect drifting outside normal driving parameters, it takes control. Although the VW system is aggressive, it can be overridden. For example, activating a turn signal or dialing in extra steering effort will disable the system.
Because of a lack of public acceptance, cars equipped with electronic steering have seen very limited computer intervention. It’s usually just enough assistance to improve handling. Cars that take complete control away from the driver better be flawless. One of the most pressing issues is how to determine when the driver is losing attention or intentionally trying to switch lanes. So the first applications of this technology are likely to be paired with adaptive cruise control.
The car we drove actually used sensors to monitor a driver’s heartbeat to determine if we were awake and alert or sleepy and dozing. As software engineers better learn such human performance, they can use all sorts of signals to activate or disable the system—body temperature, movement in the seat hands on the steering wheel, even eye movements. At this point the hardware is there, but we’re just waiting for the right computer programs.
5. Cleaner Fuel
VW and the rest of the German auto industry are taking a hard look at synthetic fuel, made by solid-to-liquid or gas-to-liquid processes. Most of these methods, including improved versions of the Fischer-Tropsch synthesis invented in the 1920s, use catalysts (usually iron or cobalt) to convert solids like coal and agricultural waste or natural gas into liquid fuel. Also under development is ethanol produced from cellulose (straw, wood and various waste materials), rather than from corn or beets, which affect food supply.
Biomass fuels, called “SunFuels” because of their renewable origin, are made by the same basic processes as other synthetic fuels. Synthetic fuel can be designed for the precise combustion characteristics needed for certain advanced engine technologies.
And what about hydrogen? Volkswagen is not particularly optimistic. The company has been developing a high-temperature fuel cell (so it needs far less cooling to continue working), but even VW engineers see fuel cells as 20 years away or more.
And as a VW engineer said, if lithium-ion or another battery technology can achieve an energy density to propel a car 200 kilometers (120 mi.) per 100 kg weight (220 pounds), “the fuel cell is surpassed.” At this point, lithium-ion is at just 7 km (4.2 mi.) per 100 kg, and the ones in development will reach 21 km (12.2 mi.) per 100 kg soon. The research is apparently underway for 70 km (42 miles) per 100 kg performance in these batteries.
6. Future Powerplants
VW’s Combined Combustion System is a modified version of its 2.0-liter four-cylinder diesel.
The near-term steps are to use fossil fuels more efficiently in piston engines such as Volkswagen’s BlueMotion TDI and 1.4-liter turbo spark ignition engine. Adjunct to these, according to VW research chief Jurgen Leohold, are gasoline engines with start-stop capability, traditional hybrids and the “range extender.” That’s a plug-in hybrid with a tiny gasoline engine to recharge the batteries for distances greater than plug-ins alone can provide—similar to the Chevrolet Volt concept.
All vehicle manufacturers are developing Homogenous Charge Compression Ignition (HCCI) engines that use spark ignition for heavy load operation but in light load can ignite a lean mixture throughout a cylinder without a spark. The “homogenous charge” is a uniform mix of air, fuel and up to 70 percent of the already-burned exhaust gas. Compression stroke brings the mixture to a controlled self-ignition state — no need for a spark. Because of the uniform mix in the cylinder, there’s no hot flame front, and the mixture burns almost instantaneously and completely throughout the cylinder. So there aren’t any “hot spots” to produce engine knocking. The engine requires spark plugs for starting and heavy loads, but in HCCI mode, it improves fuel economy about 10 to15 percent—close to a diesel. It does require a “designer” gasoline, perhaps a synthetic gasoline.
VW has gone further, using a designer gasoline in a combination mode diesel engine with what it calls Combined Combustion System (CCS). Unlike diesel injection, which occurs when the piston is at top dead center on compression stroke, the CCS begins fuel injection as the piston is still rising on compression stroke, well before top dead center. This early injection promotes good air-fuel mixing with a lot of recirculated exhaust gas. The exhaust helps delay combustion until just after top dead center. The result is about 5 percent better fuel economy than a diesel. Just as important, the fuel-air-exhaust mixture burns at lower temperatures, so there’s less formation of oxides of nitrogen (NOx)—a major air pollutant that diesels require expensive after-treatment to reduce. In the CCS engine, the “designer gasoline” is a synthetic fuel, and a test car we drove at VW’s proving grounds used SunFuel made entirely from biomass.
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