METHOD AND SYSTEM FOR OBJECT CONTROL

• US 20070288194A1
• Filed: 11/21/2006
• Published: 12/13/2007
• Est. Priority Date: 11/28/2005
• Status: Active Grant

• Current Assignee: Navisense
• Original Assignee: Nauisense LLC
• Inventors: Boillot, Marc
• Granted Patent: US 7,725,288 B2
• Time in Patent Office: Days
• US Class Current: 702/150
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/043 using propagating acoustic waves

Abstract

A system (100) and method (400) for touchless object control is provided. The system can include a sensing unit (110) for capturing a first signal (677) reflected off a first object (151) at a first time and a second signal (679) reflected off the first object at a second time, a phase detector (116) for identifying a first phase difference (601) between the first signal and the second signal, and a processor (117) for updating an expected location of the first object using the first phase difference. A first object (143) can control a movement of a second object (124) using touchless control.

Claims

1. An input device for touchless object control, comprising:

a sensing unit for capturing a first signal reflected off a first object and a second signal reflected off the first object;

a phase detector operatively coupled to the sensing unit for identifying a first phase difference between the first signal and the second signal; and

a processor operatively coupled to the phase detector and the sensing unit for updating an expected location of the first object using the first phase difference, and controlling a second object in view of the expected location.

2. The input device of claim 1, wherein the processor determines an estimated location of the object, and determines if the estimated location is within a region of relative displacement error of the expected location in view of the first phase difference.

3. The input device of claim 2, wherein the estimated location is determined from a time of flight measurement (TOF), and the relative displacement is determined from a differential time of flight measurement (dTOF).

4. The input device of claim 1, wherein the processor determines a relative displacement of the object in view of the first phase difference, the estimated location, and the expected location.

5. The input device of claim 2, wherein the processor applies a weighted average to a history of estimated locations for determining the expected location.

6. The input device of claim 1, wherein the input device is an ultrasonic sensor, an optical sensor, an imaging element, a camera element, or a laser element.

7. An input device for touchless object control, comprising:

a sensing unit for transmitting a first transmitted signal and receiving a first received signal that is reflected off an object;

a phase detector operatively coupled to the sensing unit for identifying a first phase difference between the first transmitted signal and the first received signal; and

a processor operatively coupled to the phase detector and the sensing unit for updating an expected location of the object using the first phase difference, and controlling a second object in view of the expected location.

8. The input device of claim 7, wherein the processor identifies an estimated location of the object, and determines if the estimated location is within a region of relative displacement error of the expected location in view of the first phase difference.

9. The input device of claim 7, wherein the processor determines a relative displacement of the object in view of the first phase difference, the estimated location, and the expected location.

10. The input device of claim 7, wherein the input device tracks a touchless finger movement and controls an object in accordance with the finger movement.

11. The input device of claim 7, wherein the sensing unit includes a transmitter and a receiver that generate a radiation pattern which is maximally wide in a generally vertical plane.

12. A method for touchless object, the method comprising the steps of:

monitoring a movement of an object;

estimating a location of the object to produce an estimated location;

calculating a relative displacement of the object; and

updating an expected location of the object in view of the estimated location and the relative displacement.

13. The method of claim 12, further comprising:

updating the relative displacement from the expected location to produce an updated relative displacement; and

controlling a second object in accordance with the updated relative displacement.

14. The method of claim 12, further comprising:

determining if the estimated location is within a region of relative displacement error of the expected location in view of the first phase difference; and

,

if so, updating the expected location with the estimated location and the relative displacement;

if not, updating the expected location with the relative displacement.

15. The method of claim 12, wherein calculating a relative displacement comprises:

capturing a first signal reflected off an object and a second signal reflected off the object; and

identifying a first phase difference between the first signal and the second signal.

16. The method of claim 12, wherein calculating a relative displacement comprises:

capturing a first transmitted signal and a first received signal reflected off the object; and

identifying a first phase difference between the first transmitted signal and the first received signal.

17. The method of claim 12, further comprising:

updating the relative displacement in view of the expected location and the estimated location.

18. The method of claim 12, further comprising weighting a phase difference of the relative displacement with a reciprocal of a Time of Flight (TOF) curve.

19. The method of claim 18, further comprising performing a time weighted average of expected locations for updating the relative displacement.

20. The method of claim 18, further including mitigating phase discontinuities over time by selecting a phase difference with the shortest time distance to a time weighted average of the estimated locations.