System and method for entering text in a virtual environment

• US 6,407,679 B1
• Filed: 07/30/1999
• Issued: 06/18/2002
• Est. Priority Date: 07/31/1998
• Status: Expired due to Term

• Current Assignee: The Research Foundation for The State University of New York (State University of New York)
• Original Assignee: The Research Foundation for The State University of New York (State University of New York)
• Inventors: Evans, Francine, Skiena, Steven, Varshney, Amitabh
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): WONG, ALBERT KANG
• Application Number:
  US09/364,433
• Time in Patent Office: 1,054 Days
• Field of Search: 341/20, 345/158, 345/156, 345/168, 345/701, 345/702, 345/773, 345/825, 345/811, 345/705, 400/475, 400/479.2
• US Class Current: 341/20
• CPC Class Codes: G06F 3/014 Hand-worn input/output arrangements, e.g. data gloves

Abstract

A system and method for entering text in a virtual environment by sensory gloves. The user enters a key that represents one or more letters by simulating a press of a keyboard in the gloves. The user calibrates the gloves by entering text, during which time the system establishes threshold values that represent simulated presses for each finger. After the initial calibration of the sensory gloves, the user enters text with simulated finger presses. The system distinguishes which movements are intended as simulated finger presses by examining the relative motions of fingers and maintaining dynamic thresholds. Errors are alleviated by providing feedback to the user, such as beeps and a visual display of the fingers and the current text. Because keys may represent more than one character, the system determines the intended text by probabilistic analysis and the Viterbi algorithm.

Claims

1. A method for entering text in a virtual reality apparatus, said apparatus having at least one sensor glove which includes a plurality of fingers, said glove being utilized to input position data, comprising the steps of:

loading and initializing a dictionary;

specifying a key that represents at least one character for each finger press movement;

calibrating the at least one glove by establishing threshold values through a user inputting a sample sequence, said threshold values indicating an occurrence of a finger press;

monitoring the positions of the plurality of the fingers by the at least one sensor glove;

determining if a finger press was intended when at least one finger passes a threshold;

providing feedback to the user to indicate that a key was entered when there is a finger press;

when there is a finger press, storing the key of that finger;

after storing the key of that finger, separating key words by recognizing spaces in the stored sequence of keys, matching the key words with one or more words in the dictionary, generating all possible permutations of word sequences, and selecting the most probable word sequence or partial sentence;

when a partial sentence is selected, generating feedback to the user concerning the selected partial sentence;

returning to said monitoring step; and

if the user indicates the end of a sentence, erasing the stored sequence of keys, storing the last most probable word sequence as a sentence, and returning to said monitoring step.

2. The method of claim 1, wherein said loading and initializing the dictionary comprises the steps of:

converting each word of the dictionary into its key equivalent; and

storing each word in a searchable data structure by its key equivalent.

3. The method of claim 2, wherein said searchable data structure is a trie.

4. The method of claim 1, wherein said monitoring step comprises the sub-steps of:

determining if any finger has passed the threshold;

determining if any finger has passed the threshold minus a constant;

if at least one finger has passed the threshold minus a constant, replacing the current threshold with the value of the current threshold minus the constant; and

returning to said determining step.

5. The method of claim 1, wherein said determining step comprises the sub-steps of:

determining if only one finger passed the threshold;

if more than one finger passed the threshold, choosing the finger value closest to the threshold for the intended key; and

if only one finger passed the threshold, choosing that finger as the intended key.

6. The method of claim 1, wherein said dictionary has frequency probabilities associated with each word and said matching the key words with one or more words in the dictionary comprises:

searching the data structure for all matches with the key word;

if there is no match, searching for partial word matches;

if there is no partial word match, searching for prefix/suffix matches; and

if there is no prefix/suffix match, constructing a word using character probabilities and letter transition probabilities.

7. The method of claim 1, wherein said selecting the most probable word sequence or partial sentence uses the Viterbi algorithm, grammatical constraints, and word-pair frequency to assign probabilities to each partial sentence.

8. The method of claim 1, wherein said text is Chinese symbols and said keys are phonetic symbols.

9. The method of claim 1, wherein said step of specifying a key is determined statistically or ergonomically.

10. The method of claim 1, wherein said feedback is audio or visual.

11. The method of claim 1, wherein said feedback is tactile.

12. The method of claim 1, wherein said position data is generated by cameras, sensor rings, or headgear.