Feeling and seeing: issues in force display

Abstract

This paper is about using the sense of touch, the hapti c system, as part of our everyday interface wit h computationally created worlds .In Part I, we discuss a particular system, called Sandpaper, designed for experimenting with feeling texture .In part II, we discuss how control analysis helps us understand th e behavior of the types of hardware and software we use t o implement force display .We will not comprehensively review the literature of forc e display devices and their applications; descriptions can b e found in e .g .[Sutherland651, [No11721, [Batter721 , [Atkinson77l, [Brooks88j, [Ouh-young881, [Smith881 , Part IForce display technology works by using mechanica l actuators to apply forces to the user, By simulating th e physics of the user's virtual world, we compute these forces in real-time, then send them to the actuators so that the user feels them, The force display technology we use in th e Sandpaper system is a motor-driven two-degree of freedo m joystick (built by Max Behensky and Doug Milliken) .Th e joystick position is reported to the software, whic h computes the appropriate forces for the joystick's motors .Why create texture?Force display is especially useful for communicating surfac e texture and bulk properties of objects and environments a s well as dynamics of objects .In this way force display technologies augment the strengths of computer-generate d graphics and sound in creating convincingly realistic environments (figures 1, 4) .In the Sandpaper system, we use a novel technique to allo w the user to feel textures .We create very small virtua l