DyM Podcast

I bought a secpond hand Roomba-Irobot from Ebay and tried to understand how this robotic vaccum cleaner works. Below is my Undesrtanding from its behaviour. But first lets watch a video of Roomba movement on the floor when you turn it on:

This is my understanding from the way that Roomba 650 moves. Its important to mention that Roomba 650 is an older version of vacum cleaners and they do not use mapping (slam- simultanous localization and mapping) techniques to identify the sournding environment. However it uses Infrared radar to find out the dimension of the room. As its shown in the picture below:

Roomba at the beginning send IR signals around and tries to see how big is the room. It moves in a circle and this circle gets bigger and bigger then it moves toward the walls and tries to reach the corners. on the Top surface of the Bumper the IR sensor is located which identifies the size of the room also in the model of 650, there is an ultrasound sensor that measures the distance to the front object for better maneuverability. Of course these are just my guesses since Irobot has never published how its robots work. There are also 4 cliff sensors that are light sensors. they have dual use of avoiding steps and also identify dirt on the floor. there are 2 mechanical switches that when roomba colides with the object get activated and force the roomba to turn untill the bumper is free of collision. Roomba has two motor which controls the direction and one small motor for the small brush and one motor for the main brishes. it also has a small motor used as the vaccum. Below is the list of the sensor and motors used in the roomba:

The motors are brushless DC motors which use Belt to move the other components inside the plastic housing:

I hope you got a better view now about Irobot 650. the newer version have all the access to SLAM techniques which makes the motion much more efficienta and keeps the energy consumtion optimal. It helps the robot to localize its position regarding to the charging station and therfor the autonomous level is at higher level. I will in future try to write as well a blog about the newer version of Irobot. until then hope you enjoyed this episode 😉