Radio frequency tracking system

• US 6,094,188 A
• Filed: 12/05/1994
• Issued: 07/25/2000
• Est. Priority Date: 11/30/1990
• Status: Expired due to Term

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Grimaud, Jean-Jacques, Horton, Robert, Teitel, Michael, Maddy, Daniel
• Primary Examiner(s): Mengistu, Amare
• Application Number:
  US08/354,018
• Time in Patent Office: 2,059 Days
• Field of Search: 345/156, 345/157, 345/158, 345/163-166, 341/31, 341/20, 341/22, 340/825.22, 340/825.19, 340/407.01, 340/407.02, 342/126, 434/45
• US Class Current: 345/158
• CPC Class Codes: G06F 3/014 Hand-worn input/output arrangements, e.g. data gloves
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors

Abstract

A method and apparatus is disclosed for transmitting data about an object within a defined field and using the transmitted data to generate a virtual object on the display screen of a computer. In one embodiment of the present invention the object used to transmit input data is a wireless glove assembly. The glove assembly supports a transmitting device which transmits data bursts, containing position and gesture information, in the radio frequency wavelength to four stationary receivers. The received signal is converted to a digital signal and input to a microprocessor control unit. The software used in the microprocessor control unit uses an averaging method to generate a virtual object on the computer display screen. The position of the virtual object is calculated based on the strength of the signal received. The movement of the virtual object on the computer display screen is in the same direction as and is proportional to the glove movement.

Claims

1. A system for estimating a position of an object, comprising:

a transmitter, disposed on said object, which transmits signals;

a plurality of receivers which receive the signals transmitted by the transmitter; and

means for estimating a position of said object by averaging strengths of the signals received by at least some of said plurality of receivers.

2. A system according to claim 1, wherein:

strengths of signals from a first plurality of receivers are used to estimate a position along an X axis and strengths of signals from a second plurality of receivers are used to estimate a position along a Y axis.

3. A system according to claim 1, wherein a position along a Z axis is estimated by averaging strengths of signals received by each of said plurality of receivers.

4. A system according to claim 1, wherein said transmitter is radio frequency transmitter.

5. A system according to claim 1, further comprising:

a display for displaying the estimated position of said object.

6. A system according to claim 1, wherein:

said object is a wireless glove assembly.

7. A system according to claim 1, further comprising:

means for generating a virtual object on a screen using an estimated position of said object determined by the means for estimating a position.

8. A system according to claim 1, wherein:

the means for estimating the position of said object inputs the signals received by each of the receivers, the strength of the signals input by the means for estimating corresponding to a distance between one of the receivers and the transmitter.

9. A method for estimating a position of an object comprising the steps of:

transmitting a signal by a transmitter which is disposed on said object;

receiving said transmitted signal by a plurality of receivers; and

estimating a position of said object by averaging strengths of signals received by at least some of said plurality of receivers.

10. A method according to claim 9, wherein:

said estimating step uses strengths of signals from a first plurality of receivers to estimate a position along an X axis, and uses strengths of signals from a second plurality of receivers to estimate a position along a Y axis.

11. A method according to claim 9, wherein:

said estimating step uses strengths of signals from each of said plurality of receivers to estimate a position along a Z axis.

12. A method according to claim 9, wherein said transmitting step transmits radio frequencies.

13. A method according to claim 9, further comprising the step of:

displaying the estimated position of said object.

14. A method according to claim 9, wherein:

said object is a wireless glove assembly and said step of transmitting a signal by a transmitter disposed on said object transmits a signal by the transmitter which is disposed on the wireless glove assembly.

15. A method according to claim 9, further comprising the step of:

generating a virtual object on a screen using an estimated position of said object determined by the step of estimating a position.

16. A method according to claim 9, wherein:

the step of estimating the position of said object inputs the signals received by each of the receivers, the strength of the signals input by the step of estimating corresponding to a distance between one of the receivers and the transmitter.