Roomba - Description

Description

All Roomba models are disc-shaped, 34 cm (13") in diameter and less than 9 cm (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 three generations of Roomba units: the first-generation original models, the second-generation "Discovery" series; and the newest third-generation 500 /600 /700 Series.

All versions of the Roomba utilize a pair of brushes, rotating in opposite directions, to pick up debris from the floor. In most models, the brushes are then followed by a squeegee vacuum, by which the airflow is directed 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 operates with removable nickel-metal hydride batteries (NiMH), which must be recharged regularly from a wall power adaptor. Newer second- and third-generation models have a self-charging homebase which they automatically try to find (via its infrared beacons). Charging on the homebase takes about three hours. All second- and most third-generation Roombas can be used with the homebase, even if they did not come packaged with it. First- and early second-generation models came packaged with a 12-hour "standard" charger, although an optional 2.7-hour Rapid Charger was sold by iRobot to charge battery packs externally from the robot. Third-generation Roombas use internal batteries not intended to be routinely swapped (a screwdriver must be used to remove the bottom plate to gain access to the battery).

Four infrared "cliff sensors" on the bottom of the Roomba's bumper prevent it from falling off ledges such as the top steps of stairways. Most second- and third-generation models have internal acoustic-based dirt sensors that allow them to detect particularly dirty spots (zones having excess particulates) and focus on those areas accordingly. Many second- and third -generation Roombas come packaged with IR (infrared) remote controls, allowing a human operator to "drive" the robot to areas to be specially cleaned.

Some higher-end 500 and 700 series robots are compatible with "Virtual Wall Lighthouses", using an internal radio-frequency transmitter/receiver to communicate. These more-advanced Virtual Wall accessories have a mode of operation that confines a Roomba to a fixed area to be cleaned, but later allows the cleaner to proceed to the next space to be cleaned.

iRobot has released several types of dust and debris collection bins for the 500 Series robots. The standard "Vacuum Bin" incorporates the separate squeegee vacuum, as with all prior models. The "High Capacity Sweeper Bin" does not include a vacuum, but has greater capacity for debris collected by the brushes. The "Aerovac Bin" directs suction airflow through the main brushes instead of using a squeegee.