1. A system for controlling the width of a moving fabric web that is moving through a fabric compactor system, the fabric compactor system having a mechanical spreader, a compactor, a fabric conveyor and a folder, wherein the mechanical spreader is located upstream of the compactor, the compactor is located upstream of the fabric conveyor, and the fabric conveyor has a downstream end that delivers a moving fabric web to a folder, comprising:
(a) a camera, wherein the camera captures an image of a preselected portion of a moving fabric web at a preselected position on the fabric conveyor;
(b) a controller, wherein the controller receives from the camera the captured image of the preselected portion of the moving fabric web;
calculates the width of the preselected portion of the moving fabric web using the received, captured image;
compares the calculated width of the moving fabric web to a first width set point; and
causes a width setting of the mechanical spreader to change from the first width set point to a second width set point if the calculated width of the preselected portion of the moving fabric web varies from the first width set point.
2. The system of claim 1, wherein the camera is a CCD camera.
3. The system of claim 1 wherein the camera is mounted to capture a series of digital images of the fabric web.
4. The system of claim 1 wherein the camera captures an image of the entire width of the moving fabric web.
5. The system of claim 2 wherein the CCD camera is mounted between about 60 inches and 100 inches above the moving fabric web.
6. The system of claim 1 wherein, the controller determines the amount of light reflected from the moving fabric web using the received, captured image of the preselected portion of the moving fabric web.
7. The system of claim 6 further including a platen mounted proximate to the downstream end of the fabric conveyor, the platen having a color that contrasts with the color of the moving fabric web.
8. The system of claim 7, wherein the controller locates left and right edges of the moving fabric web using the captured, received image of the preselected portion of the moving fabric web based upon light contrast between the platen and the moving fabric web.
9. The system of claim 1 wherein the controller is a PID closed loop controller.
10. The system of claim 9 wherein the controller causes the width setting of the mechanical spreader to change from the first width set point to the second width set point based upon proportional, integral, and derivative relationships between the first width set point and the second width set point.
11. The system of claim 10 wherein the controller converts the sum of the proportional, integral, and derivative relationships into a pulse of power to the mechanical spreader.
12. A system for controlling the stitch count of a moving fabric web compacted by a fabric compactor system, the fabric compactor system having a compaction chamber, wherein the compaction chamber has an intake roller and a retard roller, a fabric conveyor, and a folder, wherein the fabric conveyor is downstream of the compaction chamber, the fabric conveyor has a downstream end that delivers a compacted fabric web to a folder, comprising:
(a) a camera that captures an image of a preselected portion of the moving fabric web at a preselected position of the fabric conveyor;
(b) a controller, wherein the controller
receives from the camera the captured image of the preselected portion of the moving fabric web;
calculates the stitch count of the preselected portion of the moving fabric web using the received, captured image;
compares the calculated stitch count to a first stitch count set point; and
causes a compaction setting of the compaction chamber to change from the first stitch density set point to a second stitch density set point if the calculated stitch density of the preselected portion of the moving fabric web varies from the first stitch density set point.
13. The system of claim 12 wherein the camera is a CCD camera, the CCD camera being positioned to capture an image of a preselected portion of a first side of the moving fabric web.
14. The system of claim 13 further including:
(a) a light source positioned so that it illuminates the second side of the moving fabric web; and
(b) a light controller for automatically adjusting the intensity of the light source based on a backlit image of the fabric web.
15. The system of claim 14 wherein the light controller:
receives backlit images of the fabric, calculates the light level;
compares the light level of the images to an established setpoint; and
automatically adjusts the intensity of the light.
16. The system of claim 13 wherein the CCD camera is mounted between about 1 inch and 2 inches from the moving fabric web.
17. The system of claim 14 wherein the light source is a strobe light.
18. The system of claim 17 further including a tube connected to the strobe for focusing the light on the preselected portion of the moving fabric web.
19. The system of claim 18 wherein the tube is a fiber optic tube or a liquid light tube.
20. The system of claim 14 wherein the light controller comprises:
(a) a vision processor that measures the light intensity, and adjusts the light intensity in response to measured light intensity; and
(b) a movable holder having a plurality of light filters mounted therein.
21. The system of claim 20 wherein the vision processor adjusts the light intensity by varying the light output of the light source.
22. The system of claim 20 wherein the vision processor adjusts the light intensity by moving a selected one of the plurality of light filters to a position between the light source and the preselected portion of the moving fabric web.
23. The system of claim 20 wherein the vision processor adjusts the light intensity by varying the light output of the light source and by moving a selected one of the plurality of light filters to a position between the light source and the preselected portion of the moving fabric web.
24. The system of claim 12 wherein the controller is a PID closed loop controller.
25. The system of claim 12 wherein the controller changes the rotational speed of the retard roller based on the difference between the calculated stitch count of the preselected portion of the moving fabric web and the first stitch density set point.
26. The system of claim 25 wherein the controller causes the rotational speed of the retard roller to change upon proportional, integral, and derivative relationships calculated stitch count of the preselected portion of the moving fabric web and the first stitch density set point.
27. The system of claim 26 wherein the controller converts the sum of the proportional, integral, and derivative relationships into an adjusted speed ratio for the retard roller.
28. A system for controlling the width and stitch density of a moving fabric web compacted by a fabric compactor system, the fabric compactor system having a mechanical spreader, a compaction chamber downstream from the mechanical spreader, wherein the compaction chamber has an intake roller and a retard roller, a fabric conveyor downstream of the compaction chamber, wherein the fabric conveyor has a downstream end that delivers a compacted fabric web to a folder, wherein the folder is downstream of the fabric conveyor, comprising:
(a) a width control subsystem comprising:
(i) a first camera, wherein the first camera captures an image of a preselected portion of a moving fabric web at a preselected position on the fabric conveyor;
(ii) a first controller, wherein the first controller receives from the first camera the captured image of the preselected portion of the moving fabric web;
calculates the width of the preselected portion of the moving fabric web using the received, captured image;
compares the calculated width of the moving fabric web to a first width set point; and
causes a width setting of the mechanical spreader to change from the first width set point to a second width set point if the calculated width of the preselected portion of the moving fabric web varies from the first width set point;
(b) a stitch count control subsystem comprising:
(i) a second camera that captures an image of a preselected portion of the moving fabric web;
(ii) a second controller, wherein the second controller
receives from the second camera the captured image of the preselected portion of the moving fabric web;
calculates the stitch count of the preselected portion of the moving fabric web using the received, captured image;
compares the calculated stitch count to a first stitch count set point; and
causes a compaction setting of the compaction chamber to change from the first stitch density set point to a second stitch density set point if the calculated stitch density of the preselected portion of the moving fabric web varies from the first stitch density set point.
29. The system of claim 28, wherein the first and second cameras are CCD cameras.
30. The system of claim 28 wherein the first camera captures an image of the entire width of the moving fabric web.
31. The system of claim 30 wherein the first CCD camera is mounted between about 60 inches and 100 inches above the moving fabric web.
32. The system of claim 28 wherein, the first controller determines the amount of light reflected from the moving fabric web using the received, captured image of the preselected portion of the moving fabric web.
33. The system of claim 32 further including a platen mounted proximate to the downstream end of the fabric conveyor, the platen having a color that contrasts with the color of the moving fabric web.
34. The system of claim 33, wherein the first controller locates left and right edges of the moving fabric web using the captured, received image of the preselected portion of the moving fabric web based upon light contrast between the platen and the moving fabric web.
35. The system of claim 28 wherein the first controller is a PID closed loop controller.
36. The system of claim 35 wherein the first controller causes the width setting of the mechanical spreader to change from the first width set point to the second width set point based upon proportional, integral, and derivative relationships between the first width set point and the second width set point.
37. The system of claim 36 wherein the first controller converts the sum of the proportional, integral, and derivative relationships into a pulse of power to the mechanical spreader.
38. The system of claim 29 wherein the second CCD camera is positioned to capture an image of a preselected portion of a first side of the moving fabric web.
39. The system of claim 37 further including:
(a) a light source positioned so that it illuminates the second side of the moving fabric web; and
(b) a light controller for automatically adjusting the light intensity of the light source based on a backlit image of the fabric web.
40. The system of claim 39 wherein the light controller:
receives backlit images of the fabric, calculates the light level;
compares the light level of the images to an established setpoint; and
automatically adjusts the intensity of the light.
41. The system of claim 29 wherein the second CCD camera is mounted between about 1 inch and 2 inches from the moving fabric web.
42. The system of claim 39 wherein the light source is a strobe light.
43. The system of claim 42 further including a tube connected to the strobe for focusing the light on the preselected portion of the moving fabric web.
44. The system of claim 43 wherein the tube is a fiber optic tube or a liquid light tube.
45. The system of claim 39 wherein the light controller comprises:
(a) a vision processor that measures the light intensity, and adjusts the light intensity in response to; and
(b) a movable holder having a plurality of light filters mounted therein.
46. The system of claim 45 wherein the vision processor adjusts the light intensity by varying the light output of the light source.
47. The system of claim 45 wherein the vision processor adjusts the light intensity by moving a selected one of the plurality of light filters to a position between the light source and the preselected portion of the moving fabric web.
48. The system of claim 45 wherein the vision processor adjusts the light intensity by varying the light output of the light source and by moving a selected one of the plurality of light filters to a position between the light source and the preselected portion of the moving fabric web.
49. The system of claim 28 wherein the second controller is a PID closed loop controller.
50. The system of claim 28 wherein the second controller changes the rotational speed of the retard roller based on the difference between the calculated stitch count of the preselected portion of the moving fabric web and the first stitch density set point.
51. The system of claim 50 wherein the controller causes the rotational speed of the retard roller to change upon proportional, integral, and derivative relationships calculated stitch count of the preselected portion of the moving fabric web and the first stitch density set point.
52. The system of claim 51 wherein the controller converts the sum of the proportional, integral, and derivative relationships into an adjusted speed ratio for the retard roller.
53. A method for controlling the width of a moving fabric web that is moving through a fabric compactor system, the fabric compactor system having a mechanical spreader, a compactor, a fabric conveyor and a folder, wherein the mechanical spreader is located upstream of the compactor, the compactor is located upstream of the fabric conveyor, and the fabric conveyor has a downstream end that delivers a moving fabric web to a folder, comprising:
(a) using a camera, capturing an image of a preselected portion of a moving fabric web at a preselected position on the fabric conveyor;
(b) sending the captured image of the preselected portion of the moving fabric web to a controller, wherein the controller;
calculates the width of the preselected portion of the moving fabric web using the received, captured image;
compares the calculated width of the moving fabric web to a first width set point; and
causes a width setting of the mechanical spreader to change from the first width set point to a second width set point if the calculated width of the preselected portion of the moving fabric web varies from the first width set point.
54. The method of claim 53, wherein the camera is a CCD camera.
55. The method of claim 53 wherein the camera is mounted to capture a series of digital images of the fabric web.
56. The method of claim 53 wherein the camera captures an image of the entire width of the moving fabric web.
57. The method of claim 54 wherein the CCD camera is mounted between about 60 inches and 100 inches above the moving fabric web.
58. The method of claim 51 wherein, the controller:
determines the amount of light reflected from the moving fabric web using the received, captured image of the preselected portion of the moving fabric web; and
creates a contrast sufficient to analyze the image based on the amount of reflected light.
59. The method of claim 58 further including a platen mounted proximate to the downstream end of the fabric conveyor, the platen having a color that contrasts with the color of the moving fabric web.
60. The method of claim 59, wherein the controller locates left and right edges of the moving fabric web using the captured, received image of the preselected portion of the moving fabric web based upon light contrast between the platen and the moving fabric web.
61. The method of claim 53 wherein the controller is a PID closed loop controller.
62. The method of claim 61 wherein the controller causes the width setting of the mechanical spreader to change from the first width set point to the second width set point based upon proportional, integral, and derivative relationships between the first width set point and the second width set point.
63. The system of claim 62 wherein the controller converts the sum of the proportional, integral, and derivative relationships into a pulse of power to the mechanical spreader.
64. A method for controlling the stitch count of a moving fabric web compacted by a fabric compactor system, the fabric compactor system having a compaction chamber, wherein the compaction chamber has an intake roller and a retard roller, a fabric conveyor, and a folder, wherein the fabric conveyor is downstream of the compaction chamber, the fabric conveyor has a downstream end that delivers a compacted fabric web to a folder, comprising:
(a) using a camera, capturing an image of a preselected portion of the moving fabric web at a preselected position on the fabric conveyor;
(b) sending the captured image to a controller, wherein the controller;
receives from the camera the captured image of the preselected portion of the moving fabric web;
calculates the stitch count of the preselected portion of the moving fabric web using the received, captured image;
compares the calculated stitch count to a first stitch count set point; and
causes a compaction setting of the compaction chamber to change from the first stitch density set point to a second stitch density set point if the calculated stitch density of the preselected portion of the moving fabric web varies from the first stitch density set point.
65. The method of claim 64 wherein the camera is a CCD camera, the CCD camera being positioned to capture an image of a preselected portion of a first side of the moving fabric web.
66. The method of claim 65 further including:
(a) a light source positioned so that it illuminates the second side of the moving fabric web; and
(b) a light controller for automatically adjusting the light intensity of the light source based on a backlit image of the fabric web.
67. The system of claim 66 wherein the light controller:
receives backlit images of the fabric, calculates the light level;
compares the light level of the images to an established setpoint; and
automatically adjusts the intensity of the light.
68. The method of claim 65 wherein the CCD camera is mounted between about 1 inch and 2 inches from the moving fabric web.
69. The method of claim 66 wherein the light source is a strobe light.
70. The method of claim 69 further including a tube connected to the strobe for focusing the light on the preselected portion of the moving fabric web.
71. The method of claim 70 wherein the tube is a fiber optic tube or a liquid light tube.
72. The method of claim 66 wherein the light controller comprises:
(a) a vision processor that measures the light intensity, and adjusts the light intensity in response to changes in color, weight, or thickness of the fabric web; and
(b) a movable holder having a plurality of light filters mounted therein.
73. The method of claim 72 wherein the vision processor adjusts the light intensity by varying the light output of the light source.
74. The method of claim 72 wherein the vision processor adjusts the light intensity by moving a selected one of the plurality of light filters to a position between the light source and the preselected portion of the moving fabric web.
75. The method of claim 72 wherein the vision processor adjusts the light intensity by varying the light output of the light source and by moving a selected one of the plurality of light filters to a position between the light source and the preselected portion of the moving fabric web.
76. The method of claim 64 wherein the controller is a PID closed loop controller.
77. The method of claim 64 wherein the controller changes the rotational speed of the retard roller based on the difference between the calculated stitch count of the preselected portion of the moving fabric web and the first stitch density set point.
78. The method of claim 64 wherein the controller causes the rotational speed of the retard roller to change upon proportional, integral, and derivative relationships of the calculated stitch count of the preselected portion of the moving fabric web and the first stitch density set point.
79. The method of claim 78 wherein the controller converts the sum of the proportional, integral, and derivative relationships into an adjusted speed ratio for the retard roller.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A subband processing unit (102) configured to determine a synthesis subband signal from an analysis subband signal; wherein the analysis subband signal comprises a plurality of complex valued analysis samples at different times, each having a phase and a magnitude; wherein the analysis subband signal is associated with a frequency band of an input audio signal; wherein the subband processing unit (102) comprises
a block extractor (201) configured to repeatedly
derive a frame of L input samples from the plurality of complex valued analysis samples; the frame length L being greater than one; and
apply a block hop size of p samples to the plurality of complex valued analysis samples, prior to deriving a next frame of L input samples;
thereby generating a suite of frames of L input samples;
a nonlinear frame processing unit (202) configured to determine a frame of processed samples from a frame of input samples, by determining for each processed sample of the frame:
the phase of the processed sample by offsetting the phase of the corresponding input sample; and
the magnitude of the processed sample based on the magnitude of the corresponding input sample and the magnitude of a predetermined input sample; and
an overlap and add unit (204) configured to determine the synthesis subband signal by overlapping and adding the samples of a suite of frames of processed samples; wherein the synthesis subband signal is associated with a frequency band of a signal which is time stretched andor frequency transposed with respect to the input audio signal.
2. The subband processing unit (102) of claim 1, wherein the block extractor (201) is configured to downsample the plurality of complex valued analysis samples by a subband transposition factor Q.
3. The subband processing unit (102) of claim 1, wherein the block extractor (201) is configured to interpolate two or more complex valued analysis samples to derive an input sample.
4. The subband processing unit (102) of claim 1, wherein the nonlinear frame processing unit (202) is configured to determine the magnitude of the processed sample as a mean value of the magnitude of the corresponding input sample and the magnitude of the predetermined input sample.
5. The subband processing unit (102) of claim 4, wherein the nonlinear frame processing unit (202) is configured to determine the magnitude of the processed sample as the geometric mean value of the magnitude of the corresponding input sample and the magnitude of the predetermined input sample.
6. The subband processing unit (102) of claim 5, wherein the geometric mean value is determined as the magnitude of the corresponding input sample raised to the power of (1\u2212\u03c1), multiplied by the magnitude of the predetermined input sample raised to the power of \u03c1, wherein the geometrical magnitude weighting parameter \u03c1\u03b5(0,1.
7. The subband processing unit (102) of claim 6, wherein the geometrical magnitude weighting parameter \u03c1 is a function of a subband transposition factor Q and a subband stretch factor S.
8. The subband processing unit (102) of claim 7, wherein the geometrical magnitude weighting parameter
\u03c1
=
1
–
1
QS
.
9. The subband processing unit (102) of claim 1, wherein the nonlinear frame processing unit (202) is configured to determine the phase of the processed sample by offsetting the phase of the corresponding input sample by a phase offset value which is based on the predetermined input sample from the frame of input samples, a transposition factor Q and a subband stretch factor S.
10. The subband processing unit (102) of claim 9, wherein the phase offset value is based on the predetermined input sample multiplied by (QS\u22121).
11. The subband processing unit (102) of claim 10, wherein the phase offset value is given by the predetermined input sample multiplied by (QS\u22121) plus a phase correction parameter \u03b8.
12. The subband processing unit (102) of claim 11, wherein the phase correction parameter \u03b8 is determined experimentally for a plurality of input signals having particular acoustic properties.
13. The subband processing unit (102) of claim 1, wherein the predetermined input sample is the same for each processed sample of the frame.
14. The subband processing unit (102) of claim 1, wherein the predetermined input sample is the center sample of the frame of input samples.
15. The subband processing unit (102) of claim 1, wherein the overlap and add unit (204) applies a hop size to succeeding frames of processed samples, the hop size being equal to the block hop size p multiplied by a subband stretch factor S.
16. The subband processing unit (102) of claim 1, wherein the subband processing unit (102) further comprises:
a windowing unit (203) upstream of the overlap and add unit (204) and configured to apply a window function to the frame of processed samples.
17. The subband processing unit (102) of claim 1, wherein
the subband processing unit (102) is configured to determine a plurality of synthesis subband signals from a plurality of analysis subband signals;
the plurality of analysis subband signals is associated with a plurality of frequency bands of the input audio signal; and
the plurality of synthesis subband signals is associated with a plurality of frequency bands of the signal which is time stretched andor frequency transposed with respect to the input audio signal.
18. A method for generating a synthesis subband signal that is associated with a frequency band of a signal which is time stretched andor frequency transposed with respect to an input audio signal, the method comprising:
providing an analysis subband signal which is associated with a frequency band of the input audio signal; wherein the analysis subband signal comprises a plurality of complex valued analysis samples at different times, each having a phase and a magnitude;
deriving a frame of L input samples from the plurality of complex valued analysis samples; the frame length L being greater than one;
applying a block hop size of p samples to the plurality of complex valued analysis samples, prior to deriving a next frame of L input samples; thereby generating a suite of frames of input samples;
determining a frame of processed samples from a frame of input samples, by determining for each processed sample of the frame:
the phase of the processed sample by offsetting the phase of the corresponding input sample; and
the magnitude of the processed sample based on the magnitude of the corresponding input sample and the magnitude of a predetermined input sample; and
determining the synthesis subband signal by overlapping and adding the samples of a suite of frames of processed samples.
19. A storage medium comprising a software program adapted for execution on a processor and for performing the method steps of claim 18 when carried out on a computing device.