ROBOTIC AND MAGNETIC INTERFACE
FOR FORCE INTERACTIONS WITH VIRTUAL REALITY
Greg R. Luecke
Iowa State University
Department of Mechanical Engineering
2096 Black Engineering Building
Ames, IA 50011
CONTACT INFORMATION
(515) 294-5916 (Office),
(515) 294-3261 (Fax),
grluecke@iastate.edu
WWW PAGE
http://www.public.iastate.edu/~grluecke/
PROGRAM AREA
Virtual Environments.
KEYWORDS
Force feedback, virtual interface, robotic exoskeleton, haptic device
PROJECT SUMMARY
The objective of the research in this project is to develop a haptic
interface system that allows force interactions with computer-generated
virtual reality graphical displays. This system is based on the novel
application of electromagnetic principles to couple the human hand with a
robotic manipulator. The robot manipulator provides a foundation for
providing absolute force feedback from the virtual world to the human
operator. The use of a robotic manipulator also allows a wide range of hand
motion and supports the weight of the position tracking and force generation
equipment. The use of electromagnetic principles to generate Lorenz forces
between the hand and robot provides the capability for high bandwidth,
accurate, and repeatable force control. Using this approach, the forces are
transmitted between the robot and the human without using mechanical
attachments to the robot.
The development and interfacing of the mechanical hardware used to
implement the force feedback system is a major aspect of this research. A
prototype robotic exoskeleton has been developed to track the human hand and
hold powerful magnets fixes relative to wire coils attached to the hand.
Tracking of the hand is achieved using optical sources and sensors, and
forces are generated by sending current through the coils. A six degree of
freedom robot manipulator is planned for use as the motion platform,
carrying the exoskeleton device near the hand of the user and providing
reactions for the electromagnetic forces. Virtual forces are computed from
the interactions between models of objects and the user's hand in the
virtual environment and transmitted to the human by energizing electrical
coils attached to the finger tips of the user.
The system under development will provide the human user with a unique
interface to the computer generated virtual world. This interface will
apply computer generated forces to the digits of the human operator's hand
according to an arbitrary model residing in the computer program. Although
the system will be developed for contact and manipulation of realistic
objects in a virtual environment, it will also allow humans to interact with
computer graphic images that are not based on physical systems.
Manipulation of mathematical data and interactions with virtual design
prototypes will open new avenues of human-computer interaction.
PROJECT REFERENCES
Luecke, G. R., Winkler, J., "A Magnetic Interface for Robot-Applied Virtual
Forces", Dynamic Systems and Control, DSC-Vol 55-1, 1994, pp 271-276.
AREA BACKGROUND
The use of computer-generated imagery and interactive scenes for creating
virtual environments is being applied in the areas of medical research,
manufacturing, data analysis, and entertainment. Various methods have been
used to provide interactive interfaces with the graphical environment. The
ability feel interactions with the virtual environments is known as haptic
feedback. Development of force feedback between humans and virtual
environments is a necessary next step to enhance the feeling of immersion
within VR environments and to allow natal interaction with the computer
model of the environment. Several approaches are under way to provide a
physical connection with the graphical scene, including the use of the
master end of a robotic teleoperator, mechanical attachments made directly
to the digits, and exoskeleton gloves worn to provide external forces to the
human. Electromagnetic interfaces have also been used to allow force
interactions through mouse and joystick interfaces. Extension of these
principles to allow the application of electromagnetic forces between a
robot and the human involves the issues of robot tracking and control, force
control in cooperating robotic systems, stability of sampled data systems
and real-time control.
AREA REFERENCES
Adachi, Y. 1993 "Touch and Trace on the Free Form Surface of Virtual
Object", IEEE Virtual Reality Annual International Symposium, VRAIS, '93
September 18-22, 1993, pp162-168.
Bergamasco, M., 1993, "Theoretical Study and Experiments on internal and
External Force Replication" IEEE Workshop on "Force Display in Virtual
Environments and its Application to Robotic Teleoperation", May 2, 1993,
Atlanta, Georgia.
Burdea, G., J. Zhuang, E. Roskos, D. Silver, and N. Langrana, 1992. "A
Portable Dexterous Master with Force Feedback", Presence-Teleoperators and
Virtual Environments, MIT Press, Vol1 (1), pp. 18-29.
Colgate, J. E., Grafing, P. E., Stanley, M. C., and Schenkel, G., 1993,
"Implementation of Stiff Virtual Walls In Force-Reflecting Interfaces". IEEE
Virtual Reality Annual International Symposium, VRAIS, '93 September 18-22,
1993, pp 202-208.
Massie, T. M., and J.K. Salisbury, "The PHANToM Haptic Interface: A Device
for Probing Virtual," Dynamic Systems and Control: vol. 55-1, 1994
Shimoga, K. 1993 " A Survey of Perceptual Feedback Issues in Dexterous
Telemanipulation: Part II Finger Touch Feedback" IEEE Virtual Reality
Annual International Symposium, VRAIS, '93 September 18-22, 1993.
RELATED PROGRAM AREAS
3. Other Communication Modalities.
4. Adaptive Human Interfaces.
5. Usability and User-Centered Design.
POTENTIAL RELATED PROJECTS
Providing the human being with the capability to manipulate graphical images
using natural motion and touch will be extremely important as a means of
interacting with computer models. Augmenting use of surface and volumetric
display of abstract information with force feedback can provide new paths
for intuitive solutions to these problems.