Haptic VideoSatoshi Saga∗
The University of Tokyo

1Kevin Vlack†
The University of Tokyo

Introduction

The instruction of professional skills is typically performed withconventional educational materials like video, demonstrating theoperations of an expert. There is a multitude of means for knowledge transmission in academic training, but there are relatively few
methods to transmit physical skills. Since haptic devices were introduced with the development of VR technology, some instruction
systems using force feedback have been proposed. Most systems
construct a virtual model of an actual working environment, andpresent a simulation through computer graphics and a haptic device[Kuroda et al. 2003]. There are also proposed systems that convey
skill information to the trainee by recording the movement of theexpert, and reproducing it through a haptic device [Yokokohji et al.
1996]. However, instruction is most effective when the haptic sense
is proactive. We propose “Haptic Video”, a system that records anexpert’s operations and reproduces them dynamically through haptic devices.

2 Susumu Tachi§
The University of Tokyo Z\[P]_^$`$a"^Z\[0b9^$`$[c7de<f`g$^h i2jMk)+*-,.0/213045,7698:<;=> 8@ "!$#&% '(?@ A  B@ C

DFEHGIKJML7NPOQE2RIKJGS$T?@  lmonqprPsutwvyxp7z9{|}~ { @  ?@ A  B@ C
UWVYXFigure 1: Force Displaying Method    

= >?@AB
C D EABD) *"+,- ./-10324*"+!"!$#
5 8
6 7:9;<% & ' (S TF G H
8IKJLNMPORQQ

Figure 2: Visual Displaying Method

Haptic Video

There are two core technical innovation points we implemented torealize active touch [Gibson 1962] through haptic feedback. First,
in the recording phase, the position and applied force is recorded
while the expert operates. This information is archived in a databasethat can be dynamically interpolated. In the presentation phase, theimpedance information is presented to the trainee along the trajectory direction, and virtual fixtures [Rosenberg 1993], which are likewalls with elasticity, are presented orthogonal to the trajectory direction at the same time (fig.1). As a result, the trainee will operate
to cancel the force that the expert operated, and exert the desired
force proactively. Second, the working environment around the expert’s hand is recorded through video from the expert’s viewpointin the recording phase. In the presenting phase, the playing speedof the video is dynamically changed according to location information obtained from proactive operation by the trainee. As a result,
the trainee can observe the change of the scenery at the expert’shand as an image corresponding to his own operation (fig.2). In
this manner, both vision and tactile information corresponding toan expert’s skill can be transmitted proactively, which until now
could only be obtained passively (fig.3).

3

Hiroyuki Kajimoto‡
The University of Tokyo

Future Works

With the proposed “Haptic Video” system, our goal is to realizea precise and proactive approach to transmit physical skills. By
recording the working environment as well as the movement andforce of an expert instructor, our goal is to develop an archiving
system so that all pertinent skill information can be reproduced dynamically. Another goal of us is to clarify the meaning of proactiveness for the phenomenon of the sense of touch called “active∗ e-mail: satoshi saga@ipc.i.u-tokyo.ac.jp† e-mail:vlack@star.t.u-tokyo.ac.jp‡ e-mail:kaji@star.t.u-tokyo.ac.jp§ e-mail:tachi@star.t.u-tokyo.ac.jp

Figure 3: System Overview

touch”, and to verify the effectiveness of the proposed system asa training device. Our ultimate goal is to demonstrate how haptic
devices can be used for substantial improvements of existing skills
through the recording and proactive reproduction of movement andimpedance information of an expert.

References
G IBSON , J. 1962. Observations on active touch. Psychol. Rev 69,477–491.
K URODA , Y., NAKAO , M., K URODA , T., OYAMA , H., KOMORI ,M., AND M ATSUDA , T. 2003. Interaction model between elastic
objects for accurate haptic display. In Proc. of 13th International
Conference on Artificial Reality and Telexistance, 148–153.
ROSENBERG , L. 1993. Virtual fixtures: Perceptual tools for telerobotic manipulation. In Proc. of IEEE Virtual Reality Int’l. Symposium, 76–82.
YOKOKOHJI , Y., H OLLIS , R., K ANADE , T., AND H ENMI , K.
1996. Toward machine mediated training of motor skill. In Proc.
of the IEEE International Workshop on Robot and Human Communication, 32–37.