New approach to passive infrared motion sensors signal processing for Ambient Assisted Living Applications

This paper introduces a new approach to the signal processing algorithms applied for the data provided by passive infrared (PIR) motion sensors used in Ambient Assisted Living Applications (AAL). In AAL, PIR sensors are deployed differently than in the typical security applications and different results are expected by the users from the sensors. In security applications, it is required to inform the security system as soon as possible about any movement in the observed area, while in ALL applications the system and at the end the users are interested the intensity of the movement in a given time frame (typically several seconds to a minute). Therefore, first we list the differences in the specification developed for the AAL applications compared to the typical security application, then we introduce a sensor node system architecture for wireless PIR sensor nodes including a new signal processing algorithm and a data communication method capable of fulfilling the modified requirements. An implementation of the new approach is also given in the paper detailing the hardware and software architecture and algorithms used in the sensor node. The initial test results are also shown proving the applicability of the new approach. The conclusions list possible perspective new application areas also, in which we plan to test the new sensors in the future.