Position detection with micro whistles

Abstract

This paper describes the design and detection of mechanically actuated micro whistles not equipped with any electronics. When actuated, the micro whistle generates an ultrasonic tone above the audible range. A set of 3 or more microphones in the near record this tone and the position of the whistle is calculated from the time differences of the arrivals of the acoustic signals at the different microphones. Theoretically it is possible to get an accuracy of one wave length (1.7 cm).The micro whistles are fabricated by ultrasonic hot embossing of thermoplastic foils at low-cost and their overall size is approximately 1 cm. In experiments the positions of whistles up to now were measured in a 2 m × 2 m area with an accuracy of less than 10 cm.

Ambient Assisted Living as Support for Aging in Place: Quantitative Users’ Acceptance Study on Ultrasonic Whistles

“…As ultrasonic whistles represent an innovative assistance system, the participants were informed about technical core features and application options in advance. To reach a high understandability and to provide an idea of the functions of ultrasonic whistles, a drawing of the exemplary usage situations of ultrasonic whistles was given, see Figure 2: emergency buttons (left) and sensitive floors for fall detection (right, based on [9]). In addition, we provided a short scenario to ensure that all participants had the same level of knowledge in this context:…”

“…The final ultrasonic whistle will be tiny and, thus, can be fitted in various places within the living environment such as furniture, textiles, or portable equipment on the body. Realizing an interconnectivity of infrastructure, major functions are home automation (eg, automated doors), safety prevention (eg, emergency services), and positioning (eg, fall detection) [9,10]. The handling is kept simple and also easy to use for people with disabilities, for example, by pressing a button.…”