Roomba - Operation

Operation

All Roomba models can be operated by manually carrying them to the room to be cleaned, and pressing the appropriate button. First-generation models needed to be told the size of the room via three room size buttons (Small, Medium, and Large), but this is no longer required with later models, which automatically estimate room size and adjust cleaning time accordingly.

Second- or third-generation Roombas introduced several new operating modes. "Clean" mode is the normal cleaning program, starting in a spiral and then following a wall, until the room is determined to be clean. "Spot" mode cleans a small area, using an outwards spiral pattern, followed by an inwards spiral. "Max" runs the standard cleaning algorithm until the battery is depleted. "Dock" mode, introduced with the third generation, instructs the robot to seek a self-charging Home Base, and then to recharge itself. The availability of the modes varies depending on model, generally with higher-end units having more features.

The robot's bumper detects bumping into walls and furniture, and reverses or changes its path. The third-generation Roomba, which moves faster than previous Roombas, has additional forward-looking infrared sensors (not to be confused with FLIR) in its bumper to detect obstacles. The robot then slows down when nearing obstacles to reduce its force of impact.

A second-generation Roomba may also be used with the external Scheduler accessory. It allows the Roomba to begin cleaning automatically at the time of day and on days of the week that the owner desires. This can be useful for people who want the Roomba to clean while they are away from the space to be cleaned, or in the middle of the night. Most 500 Series robots support scheduling through buttons on the unit itself, and higher-end models allow the use of a radio-frequency remote to program schedules.

The Virtual Wall accessories project infrared light beams which the Roomba will not cross. Newer model Scheduler Virtual Walls can be set up to turn on via a special radio signal at the same time a Scheduler-enabled Roomba is activated. This is desirable since the Virtual Walls are battery-powered, to avoid wasting power projecting IR beams when they are not needed.

After a sufficient period of time cleaning, the Roomba will stop and sing a few triumphant notes. The cleaning time depends on room size and, for newer models equipped with acoustic dirt sensors, volume of dirt. First-generation models must be told the room size, while second- and third-generation models estimate room size by measuring the longest straight-line run they can perform without bumping into an object. When finished cleaning, or when the battery is nearly depleted, a second- or third-generation Roomba will try to return to a Home Base if one is detected. While docked with the Home Base, a Roomba will charge its battery.

With the exception of the first-generation Roomba, an infrared remote control can also be used to control the unit, which is useful for a disabled person, or for manually directing the device to specific areas to be cleaned.

Unlike the Electrolux Trilobite vacuuming robots, Roombas do not map out the rooms they are cleaning. Instead, they rely on a few simple algorithms such as spiral cleaning (spiraling), room crossing, wall-following and random walk angle-changing after bumping into an object or wall. This design is based on MIT researcher and iRobot CTO Rodney Brooks' philosophy that robots should be like insects, equipped with simple control mechanisms tuned to their environments. The result is that although Roombas are effective at cleaning rooms, they take several times as long to do the job as a person would. The Roomba may cover some areas many times, and other areas only once or twice.

General maintenance of the Roomba consists of emptying the debris bin and cleaning the dust filter, as well as removing and cleaning the brushes. Excessive hair accumulation in the brush system can cause the brushes to stall, or overheat the brush motor, damaging the unit.