Electric cars without drivers

Autonomous vehicle in the car-sharing operation: After the renter has called for the car, it navigates autonomously to the pick-up area. Credit: © Fraunhofer IPA

E-Mobile will park independently in the future and will also be able to find the next charging station without a driver. Researchers are working on electric cars that can travel short distances autonomously. On the basis of cost-effective sensors, they are developing a dynamic model that perceives the environmental situation.

Whoever got his driver's license twenty years ago and is back in a car for the first time is going to be rubbing his eyes in amazement. Electronic helpers warn of a possible collision when parking and keep the necessary distance to the car ahead during traffic. There are lane departure, crosswind, blind spot and high beam assistants, not to mention the anti-lock system. The car is taking over step by step in the cockpit. Researchers at the Fraunhofer Institute for Manufacturing Engineering and Automation IPA are one step ahead: They are dedicated to automated driving and are working on the vehicles of tomorrow, which can drive through traffic without human assistance. In this process, the Stuttgart engineers are particularly keeping an eye on electric cars.

The specialty of the researchers at the IPA is the development of robots. In the institute building, there is a prototype that independently finds its way on its four wheels through unknown territory. The challenges that are to be mastered are similar to those for automated driving. Here, as well, sensors need to recognize the environment so that the vehicle can navigate around obstacles and find its goal. Why not take advantage of that experience and apply it to the car, say the engineers in Stuttgart. That is why, one and a half years ago, an interdisciplinary team of computer scientists, mathematicians, electrical engineers and mechatronics engineers launched the project Afkar (a German abbreviation for "autonomous driving and intelligent chassis concept for an all-electric vehicle").

In a first step, the electric car is intended to learn to find a parking space and to park without a scratch. The idea behind this is that the car should be able to recharge itself with electricity without human help. This would be particularly important for car-sharing. Imagine the following scenario: The driver easily parks the car in a properly equipped parking garage on any randomly available parking space. The car takes care of everything else itself. It communicates via a wireless interface with the charging station and the parking garage management. In this process, it provides information about its charge level and its location. If the battery is empty and a charging station is free, it maneuvers in the corresponding parking bay and is charged inductively, without a cable. Then it makes room for the next electric car and rolls to a free parking space. In this way, the few existing charging stations can be used effectively.

Necessary technology is available

"The technology needed for this scenario is already available," says Afkar project manager Benjamin Maidel. He is referring to the robots of the institute that find their way easily in a known environment, such as a factory floor. Rebuilding a similar car does not take a lot of effort. Many modern cars already have most of the sensors that are required for this. The data that these devices collect just have to be combined and interpreted accordingly so that they provide a picture of the environment. The Fraunhofer experts are currently developing the necessary technology with the help of complex simulation programs. Soon, they want to test the results in practice on a demonstration vehicle.

It becomes more difficult when a car is intended to move autonomously in traffic. This requires sensors that can look hundreds of meters ahead as well as software that can react to any unforeseen events, whether that's a building site, a thunderstorm or snow. Maidel and his team are focusing on cameras, ultrasound, radar and laser scanners that perceive the surrounding area up to a distance of 200 to 300 meters.

The Afkar group will first go with their test car to a cordoned-off test area. For public roads, a special permit is required. "Whether autonomous driving makes a breakthrough will be decided, along with the right price, by customer acceptance and the legal framework. For example, the liability for accidents has to be re-regulated. The technology will probably conquer the market step by step," says Maidel. The advantages are obvious -- particularly for car-sharing vehicles. Any customer could use his smart phone to call a car, which would then drive to the desired location. Car-sharing companies could utilize their fleets more fully than they do today.

Source: Fraunhofer-Gesellschaft

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The Composite plane life cycle assessment shows lighter planes are the future

Boeing Dreamliner 787. Credit: Image courtesy of University of Sheffield

A global fleet of composite planes could reduce carbon emissions by up to 15 per cent, but the lighter planes alone will not enable the aviation industry to meet its emissions targets, according to new research.

The study, by the Universities of Sheffield, Cambridge and University College London, is the first to carry out a comprehensive life cycle assessment (LCA) of a composite plane, such as the Boeing Dreamliner 787 or Airbus 350, and extrapolate the results to the global fleet.
The LCA covers manufacture, use and disposal, using publicly available information on the Boeing Dreamliner 787 fuselage and from the supply chain -- such as the energy usage of the robots that construct the planes. The study compares the results to the traditional -- and heavier -- aluminium planes.

Emissions during the manufacture of composite planes are over double those of aluminium planes. But because the lighter aircraft use significantly less fuel, these increased emissions are offset after just a few international flights. Over its lifetime, a composite plane creates up to 20 per cent fewer CO2 emissions than its aluminium equivalent.

Professor in Advanced Materials Technologies at the University of Sheffield, Alma Hodzic, said: "This study shows that the fuel consumption savings with composites far outweigh the increased environmental impact from their manufacture. Despite ongoing debates within the industry, the environmental and financial savings from composites mean that these materials offer a much better solution."

The researchers fed the data from the LCA into a wider transport model to gauge the impact on CO2 emissions as composite planes are introduced into the global fleet over the next 25 years, taking into account other factors including population, economic prosperity, oil prices and speed of adoption of the new technology.

The study -- published in the International Journal of Life Cycle Assessment -- estimated that by 2050, composite planes could reduce emissions from the global fleet by 14-15 per cent relative to a fleet that maintains its existing aluminium-based configuration.

Professor in Energy and Transport at UCL, Andreas Schäfer, explains: "The overall emissions reduction for the global fleet is lower than the reduction for an individual plane, partly, because by 2050, not all the fleet will be of composite construction. New planes entering the fleet before 2020 could still be in use by 2050, but the faster the uptake of this technology, the greater the environmental benefits will be."

Dr Lynette Dray from the University of Cambridge added: "Given that global air traffic is projected to increase four-fold between now and 2050, changing the materials used could avoid 500 million tonnes of CO2 emissions in 2050 alone, a value that roughly corresponds to current emission levels."

Professor Hodzic commented: "The industry target is to halve CO2 emissions for all aircrafts by 2020 and while composites will contribute to this, it cannot be achieved by the introduction of lighter composite planes alone. However, our findings show that composites -- alongside other technology and efficiency measures -- should be part of the picture."

Source: University of Sheffield

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Fracking and pollution: Technology-dependent emissions of gas extraction in the US

The KIT measurement instrument on board of a minivan directly measures atmospheric emissions on site with a high temporal resolution.
Credit: Photo: F. Geiger/KIT

Not all boreholes are the same. Scientists of the Karlsruhe Institute of Technology (KIT) used mobile measurement equipment to analyze gaseous compounds emitted by the extraction of oil and natural gas in the USA. For the first time, organic pollutants emitted during a fracking process were measured at a high temporal resolution using a vapor capture system. The highest values measured by this process exceeded typical mean values in urban air by a factor of about one thousand, as was reported in the ACP journal.

Emission of trace gases by oil and gas fields was studied by the KIT researchers in the USA (Utah and Colorado) together with US institutes. Background concentrations and the waste gas plumes of single extraction plants and fracking facilities were analyzed. The air quality measurements of several weeks duration took place under the "Uintah Basin Winter Ozone Study" coordinated by the National Oceanic and Atmospheric Administration (NOAA).

The KIT measurements focused on health-damaging aromatic hydrocarbons in air, such as carcinogenic benzene. Maximum concentrations were determined in the waste gas plumes of boreholes. Some extraction plants emitted up to about a hundred times more benzene than others. The highest values of some milligrams of benzene per cubic meter air were measured downstream of an open fracking facility, where returning drilling fluid is stored in open tanks and basins. Much better results were reached by oil and gas extraction plants and plants with closed production processes. In Germany, benzene concentration at the workplace is subject to strict limits: The Federal Emission Control Ordinance gives an annual benzene limit of five micrograms per cubic meter for the protection of human health, which is smaller than the values now measured at the open fracking facility in the US by a factor of about one thousand. The researchers published the results measured in the journal Atmospheric Chemistry and Physics ACP.

"Characteristic emissions of trace gases are encountered everywhere. These are symptomatic of gas and gas extraction. But the values measured for different technologies differ considerably," Felix Geiger of the Institute of Meteorology and Climate Research (IMK) of KIT explains. He is one of the first authors of the study. By means of closed collection tanks and so-called vapor capture systems, for instance, the gases released during operation can be collected and reduced significantly.

"The gas fields in the sparsely populated areas of North America are a good showcase for estimating the range of impacts of different extraction and fracking technologies," explains Professor Johannes Orphal, Head of IMK. "In the densely populated Germany, framework conditions are much stricter and much more attention is paid to reducing and monitoring emissions."

Fracking is increasingly discussed as a technology to extract fossil resources from unconventional deposits. Hydraulic breaking of suitable shale stone layers opens up the fossil fuels stored there and makes them accessible for economically efficient use. For this purpose, boreholes are drilled into these rock formations. Then, they are subjected to high pressure using large amounts of water and auxiliary materials, such as sand, cement, and chemicals. The oil or gas can flow to the surface through the opened microstructures in the rock. Typically, the return flow of the aqueous fracking liquid with the dissolved oil and gas constituents to the surface lasts several days until the production phase proper of purer oil or natural gas. This return flow is collected and then reused until it finally has to be disposed of. Air pollution mainly depends on the treatment of this return flow at the extraction plant. In this respect, currently practiced fracking technologies differ considerably. For the first time now, the resulting local atmospheric emissions were studied at a high temporary resolution. Based on the results, emissions can be assigned directly to the different plant sections of an extraction plant. For measurement, the newly developed, compact, and highly sensitive instrument, a so-called proton transfer reaction mass spectrometer (PTR-MS), of KIT was installed on board of a minivan and driven closer to the different extraction points, the distances being a few tens of meters. In this way, the waste gas plumes of individual extraction sources and fracking processes were studied in detail.

Source: Karlsruhe Institute of Technology

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