Human Position/Height Detection Using Analog Type Pyroelectric Sensors

Pyroelectric sensors can detect changes of infrared rays. Usually, typical pyroelectric sensors are the digital output type, used for lighting switches and security systems. We can acquire, however, limited information from such digital on or off signals. We can also acquire a wealth of sensor data by using the analog type. Thus, this paper proposes a new approach to human position detection that discriminates human height (adults or children) by using analog type pyroelectric sensors. The proposed method employs Fast Fourier Transform (FFT) to calculate human position and analyzes the spectrum distribution to discriminate between adults or children. We built an experimental room 2.5 meters square and 2.5 meters high. Analog type sensors were installed at intervals of 0.8 meters in a grid shape. The proposed position detection method can calculate human position even if two persons are in the same room. Our height detection method that discriminates between adults and children is almost 90% accurate. Future research targets are improvements in accuracy and the development of an application system using these sensors.