Variable Compliance Haptic Field Displays

Northwestern University, Evanston IL

Investigators

Abstract

Prop ID: 0413204 P I: Colgate, J. Edward Organization: Northwestern University Title: Variable Compliance Haptic Field Displays Abstract This research will address a novel class of haptic devices: "Haptic Field Displays" (HFDs). HFDs are large scale arrays of moveable pins or "tactels" covered by a flexible graphical display. HFD pin arrays will be much like the "tactile arrays" that have been developed for displaying Braille or virtual environments, but with some key differences. For instance, HFDs will be full-screen enabling scanning with the fingertip or using multiple fingers. They will operate not by actively controlling the displacement or force of each tactel, but by controlling compliance. The intellectual merit of this research stems from two sets of studies. The first is a set of psychophysical studies that will provide quantitative specifications for HFDs including the necessary dynamic range of tactel compliance and the resolution (or just noticeable difference) of compliance. These studies will also lead to an initial set of HFD primitives that naturally encode affordances (such as pushing, sliding or rotating). Finally, these experiments will assess human operator performance in using HFDs, especially in spatial localization and analog level-setting tasks. The second set of studies will address the design and integration of electronically programmable HFD tactels, each a meso-scale mechatronic system including a variable compliance mechanism, actuation and sensing. These studies will focus on the meso-scale realization of two low power "semi-active" approaches: variable damping achieved by controlling an orifice, and variable compliance achieved by placing a continuously variable transmission (CVT) between the fingertip and compliant element. Broader impacts of this research include the potential to improve the usability of graphical interfaces for normally-abled populations, as well as increase the accessibility of interfaces for differently-abled populations such as the elderly, those with low vision, and those who are blind. In addition, it has the potential to increase safety and utility in situations where high demands are placed on vision. For instance, HFDs would allow automobile drivers to focus visual attention on the road while simultaneously taking advantage of the growing assortment of electronic devices that may be found in a vehicle. This research will also impact undergraduate and graduate education at Northwestern more generally: tactel design and control will be integrated into at least two project-based courses taught by the P.I.s.