iRobot Corp, a robot maker that sells floor cleaners as well as devices that defuse bombs, introduced on Wednesday a new line of vacuums in hopes of generating cash to invest in a wider range of products.

Two new models, the Roomba 530 and Roomba 560, were scheduled to start selling on iRobot's Web site, Amazon.com and Home Shopping Network on Wednesday for $250 and $399.

The new models are more durable, have twice as much vacuum power and more sophisticated artificial intelligence technology than previous models. iRobot has sold 2 million vacuum cleaners since it introduced its first machine almost five years ago.

Improvements include new anti-tangle technology to extract the robots from power cords, sensors that slow them down as they approach walls and beacons that guide them around the house.

This is a robot that is built to survive, do the job, not get stuck, Chief Executive Colin Angle said in an interview.

He said the new models were rugged enough to be used for 45 minutes a day and last for three to five years.

Two more home robots are on their way from iRobot, but so far the company has provided little information. It has said they will be unveiled on September 27 and that they won't clean floors, mow lawns or work as butlers.

I think it is going to reinforce in people's eyes that this (company) is not a one-trick pony, he said. iRobot has a machine in place that is going to be delivering very, very cool, labor-saving robots for the home.

Robotics