コンデンサマイクロフォン型センサによる多機能センシングとセキュリティへの応用

抄録

Any sensor is more or less influenced by other physical variables that are not to be detected by it. For example pressure sensors are strongly influenced by the temperature and the acceleration. These other variables are called noise or disturbance to be minimized in the conventional sensor development. This paper proposes a novel strategy for the sensor development unlike the conventional approach above, i.e., the sensor receives all the influences of multiple physical variables, separates the influences, and reconstructs the separated multiple influences, by which a smart sensor that can judge the advanced event for a specific application can be developed. This approach is valid when an appropriate sensor exists for a specific application. In this paper we consider the security as the application and we selected a condenser microphone as the sensor. The condenser microphone is a supersensitive pressure sensor that is influenced by the pressure, acceleration, temperature and even the light emission in the wide frequency range. These variables can be separated and reconstructed for the security application. The security-sensor based on the one-microphone sensor can judge the occurrence of earthquake, fire, and invasion by a thief. Experiments carried out in a room of apartment house showed the validity of the new sensing strategy.