Optical pressure sensing for tangible user interfaces
Fabian Hennecke, Franz Berwein, Andreas Martin Butz · 2011
In this paper we present a low cost pressure sensing method for Tangible User Interface (TUI) objects on interactive surfaces, using conventional FTIR and DI tracking. While current TUIs use optical tracking for an object's position and orientation, they rely on mechanical or electric enhancements to enable sensing of other input parameters such as pressure. Our approach uses dedicated marker pads for pressure sensing embedded into an optical marker pattern for position and orientation tracking. Two different marker designs allow different precision levels: Number of Contacts (NoC) allows click sensing and Area of Contact (AoC) enables continuous pressure sensing. We describe the working principles of the marker patterns and the construction of the corresponding tangible objects. We have tested continuous pressure sensing in a preliminary user study and will also discuss limitations of our approach.