Continuous acoustic source tracking for tangible acoustic interfaces

The challenge in human computer interaction is to create tangible interfaces that will make digital world accessible through augmented physical surfaces like walls and windows. In this paper, two continuous acoustic source tracking methods are proposed which have the potential to covert a physical object into a tracking sensitive interface. The spatial likelihood method has been used to locate an acoustic source in real time. The source location is obtained from searching the maximum in the likelihood map. The Kalman filter is used to improve the trajectory estimation by predicting the location based on the previous source location and the current measurement of the source location. Finally a Linear Positioning algorithm is proposed for acoustic source tracking. This method is independent on the spatial size of the tangible object and thus applicable on large interactive surfaces without additional computation cost. Promising results have been achieved experimentally for the application of acoustic tangible interfaces.

► Two continuous acoustic source tracking methods are developed and experimented.
► The spatial likelihood method has been used to track a moving object in real time.
► The Kalman filter has been used to improve smoothness of trajectory prediction.
► The system can track a finger movement on the surface of with accuracy of 10 mm.