— Researchers at Case Western University in Ohio, US, are using robots equipped with a cross between wheels and legs called "whegs" to test a new material that mimics the gravity-defying feet of geckos and insects.
The robot's whegs are wheels with four spokes protruding at regular intervals around their edge. Small bots with strips of everyday adhesive tape attached to the spokes of their four whegs can climb walls but struggle once the tape is contaminated with dirt.
Tape featuring microscopic structures that mimic those found on the feet of geckos and wall-climbing insects could provide a way around this problem. The new material, developed by German company Gottlieb Binder, is less sticky than the adhesive tape, but works even when contaminated with dirt.
This video shows experiments involving both types of tape (8.5MB, mov format).
Another clip shows a flying robot with whegs as well as retractable wings (9MB, mov format). The robot, resembling a large winged insect, combines the ability to fly with the capacity to crawl to reach a specific location on the ground.
Both projects were demonstrated at the International Conference on Intelligent Robots and Systems (IROS), which was held in Beijing, China in October 2006.
Vertical take-off UAV
An autonomous twin-propeller aircraft capable of taking off and landing vertically and flying horizontally has been developed by Australian researchers. The machine sits on its tail and takes off like helicopter, before turning over to fly like a plane. A video shows the aircraft taking off, flying, hovering and landing again, during a test flight (7MB, wmv format).
The T-Wing, which has a wingspan of 2.4 metres, is 1.6 metres tall and weighs 30 kilograms. It has the ability to take off from any small flat area, like a forest clearing or the top of a jeep.
It has fixed wings like a normal aircraft and simply rolls over onto its belly after taking off. Having wings gives the T-Wing greater range and control than a helicopter, its makers say. The University of Sydney team also says their invention is significantly simpler than other vertical take-off designs, which tend to require engines to rotate for vertical manoeuvres.
Tricking virtual reality users into walking in circles could be the key to creating the illusion of a wider space than actually exists, according to researchers at the University of North Carolina, US.
Sharif Razzaque and colleagues used a carefully manipulated virtual environment to make test subjects feel they were walking in much larger space than in reality (11MB, mov format). Although it seemed they were covering new ground, participants were actually retracing their steps.
Shifting the virtual environment displayed through the headset when the user is turning prevents them noticing it is happening. Humans sense movement using the vestibular organs of the inner ear and any mismatch between this and what the eyes see is usually disorientating. However, when the head turns sharply, the inner ear is less accurate, so extra rotation of the scene can slip by before the eyes unnoticed.
Other researchers interested in the same problem are developing equipment that creates the illusion of walking without a person actually travelling at all (see Powered shoes perfect for a virtual stroll>, including a video demonstration).
A more natural way of simulating crowds could mean more realistic computer games and special effects. Researchers at the University of Washington, US, have developed a model that produces more natural crowds incorporating many thousands of individuals.
Most crowd simulations work from the bottom up by simulating the decisions and movements of each individual. This needs a lot of computing power and produces unrealistic results due to techniques used to limit that drain on resources.
The Washington team's alternative, top-down method, which can produce a realistic simulation movement of a large, retreating army, for example (56MB, avi format requires DivX codec).
The crowd-simulation system treats individuals in a crowd as a collection of particles with a particular goal to get to a certain place. It directs them towards their goal while taking into account a surrounding "discomfort field". This stops them crushing together, and produces realistic patterns of movement that closely match reality.
Games company Electronic Arts has licensed it for use in its next-generation games.
Journal reference: ACM Transactions on Graphics (vol 25)