Abhijeet Ravankar , Ankit A. Ravankar , Michiko Watanabe and Yohei Hoshino Paper Link image Courtesy: the Verge Public places like hospitals and industries are required to maintain standards of hygiene and cleanliness. Traditionally, the cleaning task has been performed by people. However, due to various factors like shortage of workers, unavailability of 24-h service, or health concerns related to working with toxic chemicals used for cleaning, autonomous robots have been seen as alternatives. In recent years, cleaning robots like Roomba have gained popularity. These cleaning robots have limited battery power, and therefore, efficient cleaning is important. Efforts are being undertaken to improve the efficiency of cleaning robots. The most rudimentary type of cleaning robot is the one with bump sensors and encoders, which simply keeps cleaning the room while the battery has charge. Other approaches use dirt sensors attached to the robot to clean only the untidy portions of the floor