By Michael Kahn

WASHINGTON (Reuters) - Move over R2-D2, a new robot has come to town and this one knows how to mind its manners.

Minerva the robot began guiding tours this week at the American Museum of History. But unlike the testy rolling computer from the movie ``Star Wars'' on show at another Smithsonian Museum, Minerva is user friendly.

``It finds people, is going to approach them and asks them whether they would be interested in a tour,'' said Sebastian Thrun, head of an international team from Carnegie Mellon University and the University of Bonn that developed the robot.

``It's better to have a good-spirited robot than a grumpy machine,'' he added in an interview over the weekend.

The prototype robot is able to learn about its surroundings and adapt to new situations, Thrun said during a break from working out some last minute kinks on the machine.

An on-board computer and sensors, which use infra-red lights to measure distances, help Minerva navigate and map its environment. Sound sensors work to avoid collisions -- much the same way as in bats -- by sending out sound waves and measuring how long the echo takes to bounce back, Thrun added.

``It starts exploring its environment and learns a floor plan,'' Thrun said. ``This enables it to find its place and then

to find people.''

The robot's job is to guide visitors through the ``Material World'' exhibition of artifacts that illustrate how materials have influenced the way humans live.

Minerva explains how robots fit into the history of these items. At one exhibit, Minerva explains how a clock functions but points out it cannot make decisions like a robot.

``It explains its relations to the exhibit,'' Thrun said.

For those unable to travel to Washington, built-in cameras that double as Minerva's eyes will allow computer users to take a tour from home on Thursday night by logging onto the Internet at http://www.si.edu/lemelson/minerva.htm.

Minerva is a squat, compact robot resembling a gray version of R2-D2. Its red mouth and blue eyebrows both move, depending on the robot's mood.

Minerva likes humans and responds to people touching its screen by saying: ``Oh, that tickles.'' It even complimented an underdressed reporter: ``I love your T-shirt,'' Minerva said in its soft human-like voice.

``When people approach it, Minerva starts smiling,'' Thrun said. ``I would say it's a happy robot -- when its path is blocked it says 'excuse me'.''

But the designers also added a touch of attitude. Minerva frowns when people crowd its space and blows a horn to get people to move. This is largely a safety precaution because Minerva cannot maneuver when its path is cluttered.

Hordes of people, though, trying to disturb the robot will actually help the researchers, Thrun said. The new surroundings will allow the team to see how people interact with robots and how Minerva responds when disturbed by visitors.

``This is the perfect environment for us,'' Thrun said. ''There is no better place than this museum to test it.''

Minerva cost about $30,000 to develop but since technology is rapidly becoming better and cheaper, Thrun said a similar robot will only cost a few thousand dollars in three years.

During the tours a designer will be on hand to answer questions and make sure Minerva performs well during its stint as a guide, which ends on Sept. 5.

``Our goal is to have more people touch this robot than any other robot in history,'' Thrun said.