GIVE a friend directions, such as, 鈥渋t鈥檚 across the street from a petrol station, just after a red brick building on the right鈥︹�� and you can be pretty sure they鈥檒l find what they are looking for. Robots, on the other hand, are hopeless at following such cues, because they can鈥檛 envision a perspective other than their own. But that鈥檚 about to change.
By mimicking how primates visualise an unfamiliar environment 鈥� a process called mental rotation 鈥� researchers are building a new kind of guidance system for robots.
Many species of animals perform mental rotation 鈥� a poorly understood aspect of spatial reasoning that is nonetheless an integral part of high-level cognition.
Advertisement
鈥淚f I tell you to turn left, you will probably ask whose left, mine or yours?鈥� says of Georgia Institute of Technology in Atlanta, who is leading the effort to incorporate this technique into software for controlling robots. 鈥淵ou have to transform your frame of reference,鈥� he says.
The team is now testing their software in a lab setting. The researchers first supply the robot with a destination 鈥� a simplified image of how objects in their environment will look from a given perspective. The robot then uses depth information from an on-board Kinect motion sensor to establish how objects look in its surroundings.
Once it has built a picture of where it is, the robot 鈥渕entally鈥� rotates the orientation of objects to match its destination, and then plots a path. As it trundles along, it continues to take images of its surroundings and compare them to its destination, just to make sure it is on the right track. In tests, a small four-wheeled robot used this method to find its way 6 metres across a lab floor to the right spot.
It鈥檚 a humble beginning, but Arkin says it鈥檚 the first time a robot has demonstrated the ability to receive visual instructions and act on them without a map. The work will be presented in December at the in Guangzhou, China. 鈥淲hen the world isn鈥檛 as you expect it to be, this will help you,鈥� he says, adding that the system could also be adapted to use speech recognition software to understand voice commands and use them to build a picture of the destination being described.
鈥淔or the first time a robot has the ability to receive visual instructions and act on them without a map鈥�
The team鈥檚 work is taking robotic autonomy into untested waters, says , who studies cognitive robotics at the University of California, Irvine. 鈥淭here has been some work with speech recognition but a robot that can take advice and apply it is a very open area,鈥� he says.
Giving robotic vehicles the ability to interpret an outside perspective would greatly improve their ability to navigate in the absence of conventional technologies, like GPS. 鈥淲e expect this to give a cognitive push to robot navigation. It moves you in the general direction you need to go and then your other systems take over,鈥� Arkin says.
Krichmar鈥檚 group has looked at adapting cognitive processes in rats for robotic navigation. He says that trying to transfer a model of primate cognition into robots is a big challenge, because of the higher degree of complexity.
For his part, Arkin thinks his team鈥檚 work in robots will lead to a better understanding of why primates have spatial reasoning skills in the first place. 鈥淚t will not only help us add perspective-taking and advice-taking applications to robots,鈥� he says, 鈥渂ut also help us understand processes we humans use every day, but know very little about.鈥�
Fancy a game of Tetris?
Primates are thought to navigate through new environments using mental rotation (see main story) but no one is sure how it鈥檚 done.
To find out more, Kim Wallen of Emory University in Atlanta, Georgia, has gathered a group of rhesus monkeys around computers to play what looks like a game of Tetris.
The exercises are actually a series of mental rotation tasks to help researchers understand the cognitive processes monkeys use for navigation. Field studies suggest they navigate by remembering landmarks, or else build mental maps they can refer back to. The idea behind the new lab tests is to determine if the monkeys can mentally evaluate 3D shapes.
