VW Research: Vehicle Technology for Today & Tomorrow
Issues ranging from fuels to traffic congestion are among those that are being addressed by Volkswagen researchers as the company works toward a more sustainable industry. Here is a look.
It’s called the “Forschungsfahrt.” Essentially, it is a glimpse into some of what Volkswagen Aktiengesellschaft is up to in its research labs. A glimpse at some of the things that company is willing to go public with. After all, one wouldn’t want to show too much of one’s hand, would one?
According to Prof. Dr. Jürgen Leohold, executive director of Group Research for VW, the company has created a network of research facilities, ranging from Germany (where there are 554 employees; 61 Ph.D. candidates, or “doktorands”; and 105 students) to the Volkswagen Research Lab China (where there are three employees) to Palo Alto, California, where the VW Electronic Research Lab is situated (with 48 employees and 20 students). The objective of the researchers is not to do basic research. Rather, they’re looking at how to further develop and apply ideas in a wide range of vehicle-related areas. What gets worked on, he explained, is predicated on research into technologies, customers and trends, and the competition, which are then funneled through to a long-term strategy, visions, and roadmaps, which then, in turn, specifically give rise to development programs in key areas, most of which are predicated on the notion of creating “sustainable mobility.” While there is certainly an environmental aspect to this—they are working on SunFuel, a synthetically produced fuel that is created from biomass feedstocks, but not those that would otherwise be used for food, on high-temperature fuel cells, and on jet-guided gasoline direct injection systems that minimize CO2 emissions—but there is also a recognition that sustainability goes far beyond the green: it encompasses issues including the increase in road traffic (they’re estimating increases of 20% passenger traffic and 34% in freight transportation on Germany roads by 2020) and vehicle safety.
One key point that Leohold makes that ought to be kept in mind by executives, researchers, engineers, and designers in other developed economies is that “only fast innovation” helps maintain “international competitiveness and high wages in Germany.” And certainly elsewhere.
Under the hood. In terms of engine technology, the roadmap that VW has developed to help move from a dependence on fossil fuels begins with improving the performance of traditional powertrains. This is taking a number of forms. For example, it has been determined that as much as 30% of combustion energy can be required simply to overcome friction in an engine. So they’re creating a computational method that will allow the modeling of various components, including pistons, cylinders, crankshafts, connecting rods, and valves, so as to determine how to minimize these friction losses.
It is widely known that diesel engines have an advantage compared to gasoline engines because of their low fuel consumption but that diesels have a tougher time when it comes to exhaust treatment in order to handle nitrogen oxide (NOx) and soot. Gasoline engines, on the other hand, don’t have as complex an exhaust problem, as the 3-way catalytic converter can deal with it. So one of the things that VW researchers are working on is to combine the two types of engines. The result is what they’re referring to as GCI, or gasoline compression ignition, a.k.a., HCCI, homogeneous charge compression ignition. In its combustion process, a nearly homegenous mixture of air, fuel, and exhaust gas are combined and compressed such that there is a state of controlled self-ignition. There is not an ignition spark lighting off the mixture. Rather, there is almost simultaneous combustion throughout the entire combustion chamber. This provides a comparatively lean burn and the amount of NOx is greatly reduced compared with other combustion processes; CO (carbon monoxide) emissions are low, as well. However, while this is efficient, it is also comparatively complex, given that there must be carefully controlled quantities of air, fuel, and exhaust gases and carefully controlled timing of the combustion. Presently, there is a limitation to lower load and speed ranges (e.g., between 25 and 62 mph) of the GCI engine. What VW engineers have developed is a system wherein a GCI-capable engine operates in conventional mode until the engine reaches the GCI region, at which point there is a driver-imperceptible shift into, and then out of, the GCI mode. Also in this realm of combining the best of diesel and gasoline engines, VW has taken gasoline direct injection (TSI) and diesel direct injection (TDI) and come up with a third acronym, CCS, which is “Combined Combustion System” as a descriptor for the engine that takes the compression ignition from the diesel and the homogeneous air-fuel mixture of the gas engine.
Designer fuels. However, to really make the CCS approach work, there is a recommendation that there is another fuel used, either SynFuel, produced synthetically from natural gas, or SunFuel, a second-generation biomass-based fuel. Unlike, say, ethanol, which is created, for example, from corn, SunFuel has its start as a variety of things, such as wood waste, bio-garbage, animal waste, or specially harvested crops. VW is working with Choren Industries (Frieburg, Germany), which has developed a process, CarboV, to create the SunFuel. Essentially, the feedstocks are shredded and dried (if necessary—if the water content is >30%), then undergo various reductions into gas and biological coke, and eventually a resulting mixture of hydrogen and carbon monoxide is run through a Fischer-Tropsch unit in the presence of a cobalt-based catalyst, resulting in the hydrocarbon chains from which SunFuel is derived.
High-temp fuel cell. Going beyond even these synthetic fuels, VW Research has developed a fuel-cell that is claimed to be unlike others. It is called a “high-temperature fuel cell” (HTFC) which is different than, naturally, a “low-temperature fuel cell” (LTFC). Apparently, the issue is that the LTFC operates at a membrane temperature of approximately 80°C and must be maintained at that temperature or the fuel cell breaks down. What’s more, there must be humidification of the hydrogen gas/air mixture to keep the membrane in the fuel cell stack from drying out as the gas flows through the electrolyte in the membrane of the fuel cell stack. The cooling and humidification systems add cost and complexity, according to VW researchers. The HTFC operates at up to 160°C, although 120°C is the intended operating temperature. It can operate at this thermal range without the need for the same sort of cooling and humidification systems required by the LTFC. Consequently, the cooling and water management systems for the HTFC are simpler and more compact. VW researchers developed a new type of electrode and a new membrane material that do a better job of water management within the fuel cell stack, thereby permitting the wider temperature range.
VW research on fuel cells is being performed at a tech center in Isenbüttel, which is near Wolfsburg. On site they’ve developed a hydrogen fueling station that generates hydrogen through the use of a 50m2 photovoltaic field. Vehicles can be filled with liquid hydrogen (which is at -253°C) or compressed gas at 350 bar or 750 bar.
Active sensing. Of course, fuels and energy efficiency are only one of many concerns that are being addressed in the VW technology roadmap. Others have to do with safety and efficiency, and these are based, in part, on sensors and computing power. For example, they are developing a vehicle with “sensor fusion.” That is, there would be a combination of 77-GHz far-radar, 24-GHz all-round radar, a laser sensor, video camera, GPS, and a nav system, connected on a FlexRay bus, and processed so as to provide information to the driver and adjustments to the vehicle, such as the capability of active cruise control in urban areas and lane departure intervention on the highway. In addition to this, they are working on car-to-car communications and networking the vehicle to smart systems developed for the traffic infrastructure.
VW is one of 28 German companies that are participating in a German research initiative called “AKTIV,” or “Adaptive and cooperative technologies for intelligent traffic.” There are two main projects in AKTIV, “Assistance systems/active safety” and “traffic management.” In the first-named, there is work underway on integrated lateral guidance, active hazard braking, intersection assistance, safety for pedestrians and bicyclists, and driving safety and attentiveness. Another program, this sponsored by the European Union, is called “InterSafe,” which focuses on safety at intersections. For this, VW has developed a system that provides, for example, left turn assistance. When the driver flips the turn signal stalk, the sensors in the vehicle determine whether there are any issues related to on-coming traffic; if so, a warning is provided by the turn signal indicator light turning red and an audible alert if necessary. Cross-coming traffic can also be detected. Additionally, traffic controls mounted at intersections can communicate to the vehicle via radio signals so that the speed of the vehicle can be adjusted so that it is possible to make it through the intersection while the light is green or alerts the driver that it will be necessary to begin braking because the light will be turning red.
They are also looking at how cars can communicate with one another so that traffic jams (caused, for example, by a lane being closed at a point down the road) can be ameliorated (e.g., the drivers can be advised when it is necessary to merge left or right so that there is a smoother traffic flow). Even though it is unlikely that all vehicles would be equipped with this technology, it has been determined via computer modeling that even a few cars with the capability can make a difference as regards backups.
While many of the developments in the auto industry are focused on creating products and processes that are better, faster and cheaper, as is evident from the Volkswagen Forschungsfahrt, sustainable and safer are other factors that are of key concern now and in the future.