The whirring, squeaking or clicking created by robots鈥� wheels, joints and motors are usually undesirable, and engineers work hard to minimise them. But a research team has found that they can be useful as part of an echolocation system to aid navigation and avoid crashes.
Most robots, whether they walk, roll or fly create some sort of background noise. Flying drones, in particular, are extremely noisy. at Aalborg University in Denmark and his colleagues suggest robots can take advantage of their own noise to detect obstacles such as walls or other robots, by picking up sounds reflected off these.
Robots often use infrared, ultrasonic or laser sensors to detect nearby objects, but using audio can reduce the weight, power requirements, complexity and cost involved. By simply measuring the time taken for noise from the robot to reach a surface and be reflected back to a microphone, a computer on board can spot obstacles up to a metre away.
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The researchers had earlier created a device that used a loudspeaker to beam sound around itself to navigate, just as a bat makes ultrasonic sounds during echolocation. But in experiments inside a lab, they have now proved that the background noise created by the machine can achieve the same thing.
Jensen says the approach could reduce the cost of robots and that many already have a built-in microphone that can be used.
鈥淚t could be a robot that drives around in a museum to help the guests,鈥� he says. 鈥淲ell then you would have microphones on board to pick up speech from humans, so we could use these microphones for other purposes.鈥�
But this approach might not work for all robots. 鈥淚f you make a perfectly quiet robot then you would need to create some kind of noise 鈥� either audible sounds or maybe you would go to ultrasound,鈥� Jensen says.
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