Wireless sensor and actuator network system for calling home robots

This paper presents the design and implementation of a wireless sensor and actuator network (WSAN) system for calling home robots in indoor environments. The proposed system consists of a network of wireless pyroelectric infrared (PIR) sensor nodes and a mobile actuator node. The PIR sensor nodes are deployed on the ceiling of a room to form a grid topology. The location of a person within the detection area can be calculated by a localization algorithm based on multi-sensor information fusion. Depending on the location information, the mobile node serves as a home robot that can navigate to the person asking for help. A prototype system of the proposed WSAN has been implemented. Experimental results show that both the localization accuracy and the navigation accuracy are good enough for the mobile node to put itself within easy reach. This service plays a very important role in assisting elderly and disabled people to maintain their independence and improve their quality of life in their homes.