  thumb|thumbtime=6|video of a roomba 530 in action thumb|right|roomba 530 docked in base station, a third-generation model (500 series) roomba is a series of autonomous robotic vacuum cleaners sold by irobot. roomba was introduced in 2002. , over 10 million units have been sold worldwide. roomba features a set of basic sensors that help it perform tasks. for instance, the roomba is able to change direction on encountering obstacles, detect dirty spots on the floor, and detect steep drops to keep it from falling down stairs. it uses two independently operating wheels that allow 360 degree turns in-place. additionally, it can adapt to perform other more creative tasks using an embedded computer in conjunction with the roomba open interface. ==description==  thumb|right|a selection of roomba internal parts all roomba models are disc-shaped,  (13") in diameter and less than  (3.5") high. a large contact-sensing mechanical bumper is mounted on the front half of the unit, with an omnidirectional infrared sensor at its top front center. a recessed carrying handle is fitted on the top of most units. as of 2012, there have been four generations of roomba units: the first-generation original models, the second-generation "discovery" series, the third-generation 500 series and the fourth-generation 600/700/800 series. all models have a pair of brushes, rotating in opposite directions, to pick up debris from the floor. in most models, the brushes are followed by a squeegee vacuum, which directs the airflow through a narrow slit to increase its velocity in order to collect fine dust. a horizontally mounted "side spinner" brush on the right side of the unit sweeps against walls to reach debris not accessible by the main brushes and vacuum. in the first generation of robots, the dirty air passes through the fan before reaching the filter, while later models use a fan-bypass vacuum. the roomba is powered by removable nimh 
2002_robots Home_appliance_brands IRobot Products_introduced_in_2002 Robotic_vacuum_cleaners