Mint – floor sweeping and mopping robot from Evolution Robotics

The company which designed facial recognition and location awareness systems for some of the best known consumer robotics in history, including the now-departed Sony AIBO robot dog and WowWee’s line of toy robots, introduced their competitor for the robotic cleaning market at CES 2010. Evolution Robotics presented their cleaning robot named Mint which differs from Neato XV-11 and the better known iRobot Roomba because it’s both a floor sweeper and a mop.

Mint’s unconventional square body, which is less than 25cm long and 7.5cm tall, is built to clean into hard to reach places. Mint features a front-mounted cleaning pad, allowing the cloth to clean along edges of walls and all the way into corners. Mint also has a very small footprint, letting it clean into tight spaces, between chair legs and around obstacles.

Unlike other cleaning robots, the Mint has no openings to suck up dirt or water. Instead, the base consists of two big wheels and a removable pad holder. The holder is a crucial player in the Mint’s cleaning strategy. Consumers are expected to remove the pad, which is held on with magnets, and slip on a wet or dry micro-fiber pad, replace the pad holder, set the Mint on the floor, and push a button to have it start cleaning.

For Mint, though, the key is what Evolution robotics calls “Indoor GPS” – its Northstar location technologies. The Mint will ship with a Northstar beacon, which transmits an infrared beam of light to the room’s ceiling. The beacon tells it where it is in the room, but if you turn on the Mint and forget to turn on the beacon, Mint will do it for you and even turn off the beacon when it’s done. Its makers claim that even without the beacon, Mint can get about 80 percent of its cleaning job done.

Inside the Mint is an ARM processor filled with hundreds of thousands of lines of code and the outside has infrared sensors. In tandem, they help the Mint navigate the room, track the ceiling beacon, and avoid obstacles.

To deal with different home environments, Evolution integrated a range of sensors into Mint’s design. Examples include floor sensors to detect floor transitions, enabling Mint to avoid driving onto area rugs and carpets. For cleaning on slippery floors, Mint automatically adapts to the floor and adjusts friction of the cleaning pad to maintain optimal traction with the wheels (similar to dynamic stability control on a car).

The robot goes back and forth on the floor in relatively straight lines and uses a side-to-side scrubbing motion, where the micro-fiber pad is rubbed back and forth on the floor. On the forward motion, the pad is depositing cleaning solution and on the backward trip, it’s picking up and trapping the dirt with the micro-fiber pad. By repeating the process, it simply continues to clean until its computer tells it it’s covered 100 percent of the room.