Robots learn from rats' brains

Queensland engineers have translated biological findings to probabilistic algorithms that could direct robots through complicated human environments.

While many of today's machines relied on expensive sensors and systems, the researchers hoped their software would improve domestic robots, cheaply.

Roboticist Michael Milford worked with neuroscientists to develop algorithms that mimicked three navigational systems in rats' brains: place cells; head direction cells; and grid cells.

In an article published in PLoS Computational Biology this week, he described simulating grid cells - recently discovered brain cells that helped rats contextually determine their location.

To explain the function of grid cells, Milford described getting out of a lift at an unknown floor, and deducing his location based on visual cues like vending machines and photocopiers.

"We take it for granted that we find our way to work ... [but] the problem is extremely challenging," said the Queensland University of Technology researcher.

"Robots are able to navigate to a certain point, but they just get confused and lost in an office building," he told iTnews.

The so-called RatSLAM software was installed in a 20kg Pioneer 2DXe robot with a forward facing camera that was capable of detecting visual cues, their relative bearing and distance.

The robot was placed in a maze similar to those used in experiments with rats, with random goal locations that simulated a rat's collection of randomly thrown pieces of food.

It calibrated itself using visual cues, performing up to 14 iterations per second to determine its location when placed in one of four initial starting positions.

Milford explained that environmental changes like lighting, shadows, moving vehicles and people made it difficult for robots to navigate in a human world.

Machines like the Mars Rovers and those competing in the DARPA Challenges tended to use expensive sensors - essentially "throwing a lot of money" at the problem, he said.

But a cheaper solution was needed to direct domestic robots, which were currently still in early stages of development and "very, very, very, dumb".

"The only really successful cheap robot that has occurred so far is the [iRobot Roomba] vacuum cleaner," he said. "They don't have any idea where they are; they just move around randomly."

The grid cell project was the latest in almost seven years of Milford's research into applying biological techniques to machines.

The team had been approached "occasionally" by domestic robot manufacturers, he said, but was currently focussed on research, and not commercialisation.