'Snakebot' navigates its way round slippery problem

时间:2019-03-01 08:17:01166网络整理admin

By Kurt Kleiner (Image: Dimitris Tsakiris) (Image: Dimitris Tsakiris) The sight of several robotic snakes slithering down a hallway together is enough to most people the heebie-jeebies. But Greek researchers believe teams of coordinated snake-like robots could someday be useful for remote inspection, repair, and even rescue work. A number of different research groups are developing robots that mimic real snakes ? their shape and simplicity make them ideal for crawling through pipes or exploring narrow or cluttered environments. And yet, while most of these robots can crawl along and turn on command, getting them to navigate independently has so far proven difficult. Their mode of locomotion means their body is continually changing shape and position. Michael Sfakiotakis and Dimitris Tsakiris at Foundation for Research and Technology in Heraklion, Greece have now developed a control mechanism that allows a snake-shaped robot safely navigate through an unfamiliar environment. The researchers did a lot of the work with computer simulations, but also built a simple, wheeled “snakebot” to test the control method. The team gave their robot two pairs of infrared sensors on its head, each capable of judging the distance to a nearby wall or other solid object. They also programmed the robot with a complex set of algorithms that force it to move its joints in response to its distance from an obstruction. The maths is complicated, but the result is fairly simple ? the snakebot adjusts itself until its body is equidistant from the obstacles on either side. For example, in a hallway it will move away from the nearest wall until it is slithering up the centre of the passage. And, when it comes to a corner, the snakebot will moves towards the newly opened space, gradually turning itself through the corner. This allows the robot to slither through a corridor and turn corners without bumping into any walls. See a video of the researcher’s snakebot in action (20.9MB .mov). In simulations, the same behaviour lets several robots ? with sensors along their body ? to form a team that can travel along together. The robots simply centre themselves between their nearest neighbour and the wall. See a simulation of four snakebots working together (12.6MB .mov). Rainer Worst, a robotics researcher at the Fraunhofer Institute in Germany, says that teaching a snakebot to guide itself is especially difficult, partly because its body is so long and partly because of the nature of its locomotion. Controlling undulations is not as simple as controlling rolling wheels, he told New Scientist. “This is rather impressive,” he says. Journal reference: The International Journal of Robotics Research (vol 26, p 1267) Robots – Learn more about the robotics revolution in our continually updated special report. More on these topics: