Object and movement detection

• US 8,625,846 B2
• Filed: 03/18/2009
• Issued: 01/07/2014
• Est. Priority Date: 03/18/2008
• Status: Active Grant

• Current Assignee: Elliptic Laboratories AS
• Original Assignee: Elliptic Laboratories AS
• Inventors: Dahl, Tobias
• Primary Examiner(s): BHATNAGAR, ANAND P
• Application Number:
  US12/933,393
• Publication Number:
  US 20110096954A1
• Time in Patent Office: 1,756 Days
• Field of Search: 382/100, 382/103, 382/106, 382/107, 348169-172
• US Class Current: 382/103
• CPC Class Codes: G01S 15/04 Systems determining presence of a target
• CPC Class Codes: G01S 15/62 Sense-of-movement determination G01S15/588 takes precedence
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• CPC Class Codes: G06F 3/043 using propagating acoustic waves
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0242 using matrix methods

Abstract

Motions, positions or configurations off, for example a human hand can be recognized by transmitting a plurality of transmit signals in respective time frames; receiving a plurality of receive signals; determining a plurality of channel impulse responses using the transmit and receive signals; defining a matrix of impulse responses, with impulse responses for adjacent time frames adjacent each other; and analyzing the matrix for patterns (22) corresponding to the motion position or configuration.

Claims

1. A method of recognizing motion of a human hand, the method comprising:

transmitting a plurality of transmit signals in respective time frames;

receiving a plurality of receive signals, at least some of the receive signals being reflected from the hand;

calculating a plurality of channel impulse responses using the transmit and receive signals, wherein the receive signals are convolutions of the transmit signals and the channel impulse responses;

defining a matrix of impulse responses, with impulse responses for adjacent time frames adjacent to each other; and

analysing the matrix for patterns corresponding to movement of the hand.

2. The method of claim 1, comprising recording the matrix as data in a storage medium of a computing device.

3. The method of claim 1 comprising determining motion information for multiple reflective points or parts of objects from the impulse response matrix.

4. The method of claim 1 comprising tracking the motion of a plurality of objects by analysing said matrix.

5. The method of claim 1 comprising determining the motion of an object by detecting an aggregate change in the channel impulse responses, or a predetermined portion thereof, above a threshold.

6. The method of claim 1 further comprising determining a size, shape or reflectivity of said one or more objects.

7. The method of claim 1 comprising applying to the matrix or a part of the matrix one or more functions selected from the group consisting of:

a curvilinear filter, a line filter, a straight-line filter, a sinusoidal filter, an edge filter, an up-sampling filter, a down-sampling filter, a re-sampling filter, a Hough transform, a wavelet transform, a radon transform, a pi-tau transform, a Fourier transform, a fractional Fourier transforms, a column-shift, a moving average of columns, a rolling average, an infinite impulse response filters, and a filter based on sub-band coding.

8. The method of claim 1 comprising applying to the matrix or a part of the matrix a non-horizontal averaging filter.

9. The method of claim 1 comprising applying a plurality of filters to the matrix and comparing their outputs to determine a filter that gives a strongest result overall or within a given area of the matrix.

10. The method of claim 1 comprising determining whether the output of a filter applied to the matrix exceeds a threshold.

11. The method of claim 1 comprising applying to the matrix a line filter having a roll-off at the edges of the line.

12. The method of claim 1 comprising applying to the matrix an adaptive outlier-filter that removes columns, rows or entries having a probability of noise above a threshold probability.

13. The method of claim 1 comprising matching sub-blocks or sliding sub-blocks of the matrix to a set of basis blocks.

14. The method of claim 1 wherein the step of analysing said matrix for patterns comprises recording a sequence of filters matched to respective portions of the matrix, and comparing said sequence to one or more predetermined sequences to identify a characteristic pattern in the matrix.

15. The method of claim 14 wherein said characteristic pattern corresponds to a particular gesture.

16. The method of claim 14 wherein the predetermined sequence comprises a sequence of sets of filters where any filter from the correct set can satisfy the sequence.

17. The method of claim 14 wherein the sequence of filters consists of a sequence of line filters at predetermined angles.

18. The method of claim 1 comprising receiving a plurality of receive signals at each of a plurality of receivers, defining a matrix of impulse responses for each receiver, and applying filters to each of said matrices, the filters applied to each matrix being adapted from a common velocity conjecture for said one or more objects.

19. The method of claim 1 wherein said signals are ultrasonic signals.

20. The method of claim 1 comprising using the motion of the human hand to control at least one operation of an electronic device.

21. The method of claim 1 further comprising storing results of said analysis in a memory.

22. The method of claim 1 further comprising providing a display signal for a display device.

23. An apparatus for recognising motion of a human hand comprising:

one or more transmitters arranged to transmit a plurality of transmit signals in respective time frames;

one or more receivers arranged to receive a plurality of receive signals, at least some of said receive signals being reflected from said hand; and

processing logic arranged to calculate a plurality of channel impulse responses using said transmit and receive signals wherein the receive signals are convolutions of the transmit signals and the channel impulse responses, define a matrix of impulse responses, with impulse responses for adjacent time frames adjacent each other, and analyse said matrix for patterns corresponding to movement of said hand.

24. The apparatus as claimed in claim 23 wherein at least one of said one or more transmitters is an ultrasound transmitter.

25. A computer program product comprising a non-transitory computer readable medium encoded with an information processing program for use in an information processing device, the program recognises motion of a human hand when executed, the program having inputs for a plurality of transmit signals in respective time frames and a plurality of receive signals when executed and further performs the operations comprising:

calculating a plurality of channel impulse responses using said transmit and receive signals, wherein the receive signals are convolutions of the transmit signals and the channel impulse responses;

defining a matrix of impulse responses, with impulse responses for adjacent time frames adjacent each other; and

analysing said matrix for patterns corresponding to one or more objects.

26. An electronic device comprising an apparatus for controlling at least one operation of the electronic device by recognising motion of a human hand, the apparatus comprising:

one or more transmitters arranged to transmit a plurality of transmit signals in respective time frames;

one or more receivers arranged to receive a plurality of receive signals, at least some of said receive signals being reflected from said hand; and

processing logic arranged to determine calculate a plurality of channel impulse responses using said transmit and receive signals, wherein the receive signals are convolutions of the transmit signals and the channel impulse response, define a matrix of impulse responses, with impulse responses for adjacent time frames adjacent each other, and analyse said matrix for patterns corresponding to movement of said hand.

27. The electronic device of claim 26 wherein the device is a mobile device.

28. A method of determining the state of one or more objects in an imaging field comprising:

transmitting a plurality of transmit signals in respective time frames;

receiving a plurality of receive signals;

calculating a plurality of channel impulse responses using said transmit and receive signals, wherein the receive signals are convolutions of the transmit signals and the channel impulse responses;

defining a matrix of impulse responses, with impulse responses for adjacent time frames adjacent each other; and

analysing said matrix for patterns corresponding to one or more objects.

29. The method of claim 28 comprising using said analysis to control an electronic device.

30. The method of claim 28 wherein the one or more objects includes a human hand or part thereof.

31. The method of claim 28 comprising tracking an object and controlling an electronic device in response to said tracking.

32. The method of claim 28 further comprising storing results of said analysis in a memory.

33. The method of claim 28 further comprising providing a display signal for a display device.

34. An apparatus for determining the state of one or more objects in an imaging field comprising:

one or more transmitters arranged to transmit a plurality of transmit signals in respective time frames;

one or more receivers arranged to receive a plurality of receive signals; and

processing logic arranged to calculate a plurality of channel impulse responses using said transmit and receive signals, wherein the receive signals are convolutions of the transmit signals and the channel impulse responses, define a matrix of impulse responses, with impulse responses for adjacent time frames adjacent each other, and analyse said matrix for patterns corresponding to one or more objects.

35. A computer program product comprising a non-transitory computer readable medium encoded with an information processing program for use in an information processing device, the program when executed determines the state of one or more objects in an imaging field, the program having inputs for a plurality of transmit signals in respective time frames and a plurality of receive signals and when executed further performs the operations comprising:

calculating a plurality of channel impulse responses using said transmit and receive signals, wherein the receive signals are convolutions of the transmit signals and the channel impulse responses;

defining a matrix of impulse responses, with impulse responses for adjacent time frames adjacent each other; and

analysing said matrix for patterns corresponding to one or more objects.