Thursday, April 17, 2008

Electric Solar Wind Sail Could Power Future Space Travel In Solar System


Source:
ScienceDaily (Apr. 17, 2008) — The electric solar wind sail developed at the Finnish Meteorological Institute two years ago has moved rapidly from invention towards implementation. Electric sail propulsion might have a large impact on space research and space travel throughout the solar system.
The electric solar wind sail developed by Dr. Pekka Janhunen might revolutionise travelling in space. The electric sail uses the solar wind as its thrust source and therefore needs no fuel or propellant. The solar wind is a continuous plasma stream emanating from the Sun. Changes in the properties of the solar wind cause auroral brightening and magnetic storms, among other things.
The main parts of the device are long metallic tethers and a solar-powered electron gun which keeps the tethers positively charged. The solar wind exerts a small but continuous thrust on the tethers and the spacecraft.
“We haven't encountered major problems in any of the technical fields thus far. This has already enabled us to start planning the first test mission,” says Dr. Pekka Janhunen. An important subgoal was reached when the Electronics Research Laboratory of the University of Helsinki managed to develop a method for constructing a multiline micrometeoroid-resistant tether out of very thin metal wires using ultrasonic welding. The newly developed technique allows the bonding together of thin metal wires in any geometry; thus, the method might also have spinoff applications outside the electric sail.
Electric Sail For Space Travel
The electric sail could enable faster and cheaper solar system exploration. It might also enable economic utilisation of asteroid resources for, e.g. producing rocket fuel in orbit.
“The electric sail might lower the cost of all space activities and thereby, for example, help making large solar power satellites a viable option for clean electricity production. Solar power satellites orbiting in the permanent sunshine of space could transmit electric power to Earth by microwaves without interruptions. Continuous power would be a major benefit compared to, e.g. ground-based solar power where storing the energy over night, cloudy weather and winter are tricky issues, especially here in the far North,” says Dr. Pekka Janhunen.
Component work for the electric sail was carried out at the University of Helsinki and in Germany, Sweden, Russia and Italy. The electric sail was invented as a by-product of basic research done at the Finnish Meteorological Institute on the interaction of the solar wind with planets and their atmospheres. Work on the electric sail in Finland is currently funded by the Academy of Finland and private foundations.
The first international electric sail meeting will be arranged at ESA ESTEC in Noordwijk, The Netherlands on May 19, 2008.
Adapted from materials provided by Finnish Meteorological Institute.
Fausto Intilla

Wednesday, April 16, 2008

Cycling More Intelligently


Source:
ScienceDaily (Apr. 16, 2008) — Cycling is fun – if you can find the right tread. But those who tire themselves out quickly lose the desire to conquer the world on two wheels. A remedy could soon be available in the form of adaptronic components which report inappropriate biomechanical stress.
Modern bicycles leave nothing to be desired. 21, 24, 27 gears! For many amateur cyclists, such luxury is too much of a good thing. They change gear too infrequently and too late, get out of breath and don’t enjoy the ride. At the Hannover Messe in Germany (April 21 through 25), Fraunhofer researchers are presenting a bicycle with an intelligent pedal crank that helps the biker to direct his strength into the pedals.
There are two piezo-sensors integrated in one of the pedal cranks of this bicycle. One function of the sensors is to measure the forces that propel the rider forwards and show him how ‘evenly’ he is pedaling. In the exhibited prototype, the registered data are transmitted wirelessly in real time to a PC – in practical use this would be a device such as a PDA or a cell phone.
The integrated-function pedal crank is a result of the InGuss project, whose goal is to manufacture ‘intelligent’ cast parts, by directly integrating sensors, actuators and electronic components in the parts while they are being cast. In this project, researchers at the Fraunhofer Institutes for Manufacturing Technology and Applied Materials Research IFAM, for Structural Durability and System Reliability LBF and for Integrated Circuits IIS are developing the manufacturing technology and the components to be integrated.
The special feature of the bicycle pedal crank is that the piezoceramic actuators, sensors and electronic components are integrated in the light metal components during casting. This is no easy task, for the high temperatures of over 700°C that prevail during casting can destroy the sensitive electronic and electromechanical components. “We protect the components with special insulating materials, and adapt the process accordingly to prevent them from being damaged,” says Christoph Pille of the IFAM in Bremen. This would make it possible for the first time ever to integrate components such as RFID transponders during casting in such a way that they could not be lost, enabling components to be tracked, identified and protected against product piracy.
Heiko Atzrodt of the LBF is certain that this pedal crank demonstrator is just one example out of many potential applications for the technology: “Integrated sensor and adaptronic functions are likely to make their way into numerous products before long – for instance, sensors in aircraft parts could report material fatigue before it is too late. Integrated actuators make it possible to actively influence vibrations, too.”
Adapted from materials provided by Fraunhofer-Gesellschaft.
Fausto Intilla - www.oloscience.com

Tuesday, April 15, 2008

Road Safety: The Uncrashable Car?


Source:
ScienceDaily (Apr. 15, 2008) — The largest road safety research project ever launched in Europe will usher in a series of powerful road-safety systems for European cars. But, in the long term, its basic, experimental research could lead to a car that is virtually uncrashable.
A truck exits suddenly from a side road, directly into your lane only dozens of metres ahead. Suddenly, your car issues a warning, starts applying the brakes and attempts to take evasive action. Realising impact is unavoidable; in-car safety systems pre-tension the safety belts and arm the airbag, timing its release to the second before impact.
Such is the promise of the uncrashable car, coming to a dealer near you in the perhaps not-too-distant future. The system is part of the basic research undertaken by the largest research initiative into road safety ever undertaken in Europe.
PReVENT has a budget of over €50 million and 56 partners pursuing a broad, but highly complementary programme of research. A dozen sub-projects focus on specific road-safety issues, but all projects support and feed into each other in some way.
PReVENT is studying relatively cheap, even simple, technologies – such as parking sensors and existing satellite navigation – that can be retooled to enhance driver safety. But as part of its broad and deep approach to car safety, it is also diving into more experimental and medium- to long-term systems, innovations that could appear in five-to-ten years.
The uncrashable car is a theoretical construct that concerned a handful of PReVENT’s sub-projects. But it could become far more of a reality than anyone expected.
Of course, it is impossible to stop all car collisions, but the technology could be pushed to make it increasingly unlikely and mitigate crashes when they do occur.
For example, PReVENT project WILLWARN uses wireless communication with other vehicles to alert the driver about potentially dangerous situations ahead, while MAPS&ADAS reads sat-nav maps to track approaching hazards, like bends, dips or intersections. SASPENCE looks at safe driving distances and speed, while LATERALSAFE finally brings active sensing to the blind spot.
All have their role in the uncrashable car, as do many others within the broader project. But two projects, APALACI and COMPOSE, take this a step further, actively tracking the speed and trajectories of surrounding vehicles and other road users in real time. If one vehicle suddenly stops, or a pedestrian suddenly steps onto the road, they swing into action to rapidly calculate the implications.
Predictive collision detection
APALACI is an advanced pre-crash mitigation system built round the registration of other motorists and cyclists. In the APALACI system, sensors monitor the street or road immediately around the vehicle and collect as much information about a collision as possible, before it even starts to take place.
The system uses this data to decide on the ideal safety reaction strategy. Examples include controlled braking manoeuvres, controlled activation of the occupant restraint systems or pre-arming airbag systems. The car can react far faster than the driver, cutting speed by crucial amounts to ensure unavoidable accidents are less severe.
APALACI also developed a so-called ‘Start Inhibit System’ for trucks. It surveys the blind spot immediately in front of a truck and protects pedestrians or cyclists by preventing dangerous manoeuvres.
APALACI was tested in a series of vehicles like the Fiat Stilo, the Volvo FH12 truck, the Alfa Romeo 156 and Mercedes E350. It used laser sensors, radar, software decision assistance and a variety of other technologies to achieve the goal.
Tiny changes have a huge impact
COMPOSE, on the other hand, aims more specifically to keep others, as well as its driver, safe. It can apply the brakes if a pedestrian steps onto the road, or extend the bumper, and raise the bonnet to enhance occupant protection.
Tiny differences have a huge impact on car safety. Dropping speed by 1km/h can reduce accidents with injury by 3 per cent, while braking fractions of a second sooner is enough to reduce the damage caused dramatically.
The systems were tested in the BMW 545i and the Volvo FH12 truck, and they do appreciably enhance safety. But, for all their potential, these systems remain, for now, the preserve of the future.
“The teams developed sophisticated algorithms to track all these elements in the landscape,” explains Matthias Schulze, coordinator of the EU-funded PReVENT project and Senior Manager for ITS & Services at Daimler AG. “But they require enormous computer power to keep track of all the various elements, so this work is aimed at basic research, establishing how it could be done. It will be a while before in-car computers are sophisticated enough to use these systems.”
Nonetheless, they do provide tools that automakers can use to mitigate the potential for accidents, and they provide a clear research roadmap for the uncrashable car of the future.
Adapted from materials provided by ICT Results.
Fausto Intilla