Forearm-supported exoskeleton hand-tracking device

• US 6,104,379 A
• Filed: 12/10/1997
• Issued: 08/15/2000
• Est. Priority Date: 12/11/1996
• Status: Expired due to Term

• Current Assignee: Immersion Corporation
• Original Assignee: Virtual Technologies, Inc. (Immersion Corporation)
• Inventors: Kramer, James F., Yim, Mark, Petrich, Kyle L., Wagner, Joe, Vargas, Jaime S.
• Primary Examiner(s): Hjerpe, Richard A.
• Assistant Examiner(s): NGUYEN, KIMNHUNG T
• Application Number:
  US08/988,602
• Time in Patent Office: 979 Days
• Field of Search: 345/157, 345/158, 345/156, 345/159, 340/709
• US Class Current: 345/157
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/014 Hand-worn input/output arrangements, e.g. data gloves

Abstract

A man-machine interface device is provided which employs rigid links interconnected by measured revolute joints to provide the position of a hand relative to a reference location, such as a desk, keyboard or chair. By proper selection of kinematic structure, and by placing one of the joints near the elbow and extending one of the links along the line of the forearm, translation of the joint-link structure is minimized, hence the undesirable perception of friction and inertia are also minimized. When Hall-Effect sensors are used as the revolute joint goniometers, the permanent magnets of neighboring joints are placed in the same link so the effects of magnetic field interference can be calibrated out. A hand-sensing joint-link device as described herein can produce data which is more noise free, at a higher sample rate, with less latency and more robust that competing electromagnetic, optical and ultrasonic sensing technologies, without adding much encumbrance. The output from the hand-sensing device may be used to produce a graphical "virtual hand" on a computer monitor which mimics the movement of the measured physical hand. The hand-sensing joint-link device may also be used with a finger-sensing joint-link device to provide data on the movements of the fingers and hand. When a right and left finger- and hand-sensing joint-link devices are used, the wearer can use both hands to manipulate virtual objects on a computer monitor.

Claims

1. A device for measuring the position of a hand in space, said device comprising:

a hand mount and a forearm mount;

means for defining a site of reference;

at least 3 links joined by revolute joints, each of said revolute joints comprising a goniometer; and

one of said links positioned to parallel a forearm, connected to said hand mount proximal to one terminus and supported by said forearm mount.

2. A device according to claim 1, wherein said goniometers comprise Hall-Effect sensors.

3. A device according to claim 1, wherein said reference means is a block.

4. A device according to claim 1, wherein said reference means is attachment means for attachment to a surface.

5. A device according to claim 1, wherein said hand mount is a glove comprising a reinforced portion attached to a link.

12. A device according to claim 1, said device comprising 5 links joined by revolute joints, each of said revolute joints comprising a goniometer.

6. A device for measuring the position of a hand in space, said device comprising:

a hand mount for attachment to a hand;

a forearm mount comprising a clip and a loop;

a reference link for defining a site of reference;

a linkage system comprising links joined by revolute joints, each of said revolute joints comprising a goniometer, comprising at one end said reference link and at the other end connection means for connection to said hand mount;

one of said links positioned to parallel a forearm, extending through said loop and supported by said forearm mount.

7. A system for measuring the position of a physical hand and producing a graphical image of said hand on a monitor screen which follows the movements of the physical hand, said system comprising:

a linkage system comprising;

a hand mount and a forearm mount;

means for defining a site of reference;

at least 5 links joined by revolute joints, each of said revolute joints comprising a goniometer; and

one of said links positioned to parallel a forearm, connected to said hand mount proximal to one terminus and supported by said forearm mount;

electrical signal transmitting means connected to said goniometers for transmitting signals from said goniometers to a signal processing means for processing said signals and determining the position of said hand and sending a graphical signal to a monitor screen.

8. A system according to claim 7, comprising left and right linkage systems.

9. A system according to claim 7, wherein said forearm mount comprises forearm fastening means supporting a channel for receiving a link.

10. A system according to claim 7, wherein said goniometers comprise Hall-Effect sensors.

11. A Hall-Effect sensor assembly comprising:

three links interconnected by two joints, said three links consisting of first and second terminal links and a middle link;

said middle link housing two permanent magnets in fixed relationship; and

Hall-Effect sensor elements in each of said first and second terminal links, each of said elements positioned in functional relationship to a corresponding permanent magnet.