Lausanne

Gimball: A crash-happy flying robot.

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Gimball bumps into and ricochets off of obstacles, rather than avoiding them. This 34 centimeter in diameter spherical flying robot buzzes around the most unpredictable, chaotic environments, without the need for fragile detection sensors. This resiliency to injury, inspired by insects, is what sets it apart from other flying robots. Gimball is protected by a spherical, elastic cage which enables it to absorb and rebound from shocks. It keeps its balance using a gyroscopic stabilization system. When tested in the forests above Lausanne, Switzerland, it performed brilliantly, careening from tree trunk to tree trunk but staying on course. It will be presented in public at the IREX conference in Tokyo, Japan from November 5-9, 2013.

Powered by twin propellers and steered by fins, Gimball can stay on course despite its numerous collisions. This feat was a formidable challenge for EPFL PhD student Adrien Briod. “The idea was for the robot’s body to stay balanced after a collision, so that it can keep to its trajectory,” he explains. “Its predecessors, which weren’t stabilized, tended to take off in random directions after impact.” With colleague Przemyslaw Mariusz Kornatowski, Briod developed the gyroscopic  consisting of a double carbon-fiber ring that keeps the robot oriented vertically, while the cage absorbs as it rotates.

Going sensor-free: insect-inspired design

Most robots navigate using a complex network of sensors, which allow them to avoid obstacles by reconstructing the environment around them. It’s an inconvenient method, says Briod. “The sensors are heavy and fragile. And they can’t operate in certain conditions, for example if the environment is full of smoke.”

Gimball’s robustness lies in its technological simplicity, says Briod. “Flying insects handle collisions quite well. For them, shocks aren’t really accidents, because they’re designed to bounce back from them. This is the direction we decided to take in our research.”

The flying  is prepared to deal with the most difficult terrain out there. “Our objective was exactly that – to be able to operate where other robots can’t go, such as a building that has collapsed in an earthquake. The on-board camera can provide valuable information to emergency personnel.” The scientist had an opportunity to test his prototype in a Swiss pine forest. Fitted out with just a compass and an altitude sensor, Gimball demonstrated its ability to maintain its course over several hundred meters despite colliding with several tree trunks along the way.

Gimball is the latest in a long line of colliding robots developed in the laboratory of EPFL professor Dario Floreano. But its stabilization system, spherical shape and ultralight weight – barely 370 grams – demonstrate the potential of the concept better than ever before. “The mechanics must also be intelligent, since complex obstacle avoidance systems are not sufficient,” says Briod. Even so, he insists, “we’re not yet ready to compete with our model. Insects are still superior.”

Suboptimal access to primary healthcare among street-based sex workers in southwest Switzerland.

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Abstract

Objectives Street-based sex workers (SSWs) in Lausanne, Switzerland, are poorly characterised. We set out to quantify potential vulnerability factors in this population and to examine SSW healthcare use and unmet healthcare requirements.

Methods We conducted a cross-sectional questionnaire-based survey among SSWs working in Lausanne’s red light district between 1 February and 31 July 2010, examining SSW socio-demographic characteristics and factors related to their healthcare.

Results We interviewed 50 SSWs (76% of those approached). A fifth conducted their interviews in French, the official language in Lausanne. 48 participants (96%) were migrants, of whom 33/48 (69%) held no residence permit. 22/50 (44%) had been educated beyond obligatory schooling. 28/50 (56%) had no health insurance. 18/50 (36%) had been victims of physical violence. While 36/50 (72%) had seen a doctor during the preceding 12 months, only 15/50 (30%) were aware of a free clinic for individuals without health insurance. Those unaware of free services consulted emergency departments or doctors outside Switzerland. Gynaecology, primary healthcare and dental services were most often listed as needed. Two individuals (of 50, 4%) disclosed positive HIV status; of the others, 24/48 (50%) had never had an HIV test.

Conclusions This vulnerable population comprises SSWs who, whether through mobility, insufficient education or language barriers, are unaware of services they are entitled to. With half the participants reporting no HIV testing, there is a need to enhance awareness of available facilities as well as to increase provision and uptake of HIV testing.

Source: PMJ. BMJ