Machine vision system utilizing programmable optical parallel processing

• US 4,462,046 A
• Filed: 07/02/1982
• Issued: 07/24/1984
• Est. Priority Date: 07/02/1982
• Status: Expired due to Fees

• Current Assignee: Robert L. Jones Jr
• Original Assignee: AMAF Industries, Inc.
• Inventors: Spight, Carl
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US06/394,812
• Time in Patent Office: 753 Days
• Field of Search: 358/101, 358/93, 358/107, 358/106, 382/42, 364/822, 350/162.13, 350/162.14, 356/393, 356/398
• US Class Current: 348/94
• CPC Class Codes: G06V 10/88 Image or video recognition using optical means, e.g. reference filters, holographic masks, frequency domain filters or spatial domain filters

Abstract

An object or scene viewed by the programmable optical processor based machine vision system is converted into a video signal representative of a spatial orientation and position of a viewed object being viewed. Reference information stored within a system control processor and indicative of a desired object to be identified and its spatial orientation and position of is used to produce a reference video signal. Both the object video signal representative of the object being viewed and the reference video signal representative of the desired object to be identified are converted into incoherent optical representations of these signals which are optically parallel processed in order to obtain a cross-correlation of the respective signals. This cross-correlation is converted into an electrical signal and is evaluated using any suitable known correlation evaluation technique in order to determine whether a high degree of correlation exists between the object being viewed and its position and orientation and the reference signal indicative of a desired object to be identified and its orientation. If a high degree of correlation exists, the effector control processor is provided with information related to the object so that the effector control processor may control a robotic manipulator in a desired manner. If a high degree of correlation does not exist between the respective signals, new object signal or reference signal information related to the object being viewed is iteratively correlated with the remaining original signal in order to determine the degree of correlation between these two signals.

Claims

1. A vision system for an industrial robot, said vision system identifying and determining the location and spatial orientation of an object being viewed and comprising:

input means for producing an object signal indicative of said object being viewed;

reference generator means for producing a reference signal indicative of a spatial orientation of a desired object to be identified;

correlation means for cross-correlating said object signal and said reference signal to produce a correlated signal; and

discrimination means for determining the degree of correlation between said object signal and said reference signal, a high degree of correlation indicating that said object being viewed is said desired object to be identified arranged in the spatial orientation of said reference signal;

said reference generator means iteratively producing new reference signals indicative of a new spatial orientation of said desired object to be identified for cross-correlation and determination by said correlation means and said discrimination means.

2. The system of claim 1 wherein said input means includes a plurality of video monitors and means for multiplexing the outputs produced by said plurality of video monitors.

3. The system of claim 1 wherein said reference generator means includes;

memory means for storing information representative of said reference signal;

processing means for recalling said information from said memory means and for producing a video signal representative thereof; and

display means for converting said video signal into an optical reference signal.

4. The system of claim 3 wherein said input means produces an optical object signal.

5. The system of claim 4 wherein said input means includes;

at least one video monitor means for converting an optical impression of said object being viewed into at least one video signal; and

means for converting said at least one video signal into said optical object signal.

6. The system of claim 4 wherein said correlation means includes;

object transform means for optically taking the Fourier transform of said optical object signal;

reference transform means for optically taking the Fourier transform of said optical reference signal;

combination means for optically adding the Fourier transform of said optical object signal and said optical reference signal to produce an optical sum signal;

squaring means receiving and optically squaring said sum signal to produce a product signal;

inverse transform means for optically taking the inverse Fourier transform of said optical product signal to produce a correlated signal.

7. The system of claim 6 wherein said discrimination means is implemented with a digital processing computer.

8. The system of claim 7 further comprising:

`robotic effector means for manipulating the object being viewed; and

effector control processor means for controlling said robotic effector means to perform a desired task;

said discrimination means, upon detection of a high degree of correlation, providing said effector control processor means with information about said object being viewed necessary to perform said desired task.

9. The system of claim 8 further comprising:

optical to electrical conversion means for converting said optical correlated signal into its electrical counterpart;

said discrimination means detecting the degree of correlation present in the electrical correlated signal.

10. The system of claim 9 further comprising sensor control means for controlling the gain and synchronization of said optical to electrical conversion means.

11. The system of claim 2 further comprising sensor control means for controlling the gain and synchronization of said means for multiplexing.

12. The system of claim 4 further comprising means for generating coherent light;

said display means and input means modulating said coherent light to produce said optical reference signal and optical object signal, respectively.

13. The system of claim 12 wherein said coherent light is modulated in said display means and input means by spacial light modulators.

14. The system of claim 1 wherein said correlation means cross-correlates said object signal and reference signal with parallel optical processing.

15. The system of claim 14 wherein coherent light is used for said parallel optical processing.

16. The system of claim 6 wherein said object transform means, reference transform means, combination means and inverse transform means utilize coherent light.

17. The system of claim 15 or 16 further comprising a laser producing said coherent light.

18. The system of claim 17 further comprising illumination means for lighting said object being viewed, said illumination means including;

means for receiving said coherent light from said laser; and

diffusion means for diffusing said coherent light.

40. The system of claims 1, 19 or 39 wherein said system identifies and determines the location being viewed in a substantially real-time fashion.

19. A vision system for a industrial robot, said vision system identifying and determining the location and orientation of an object being viewed and comprising:

input means for viewing said object from a plurality of directions and sequentially generating object signals, each indicative of a particular viewed spatial orientation of said object being viewed;

reference generator means for producing a reference signal indicative of a desired object to be identified;

correlation means for cross-correlating each of said object signals with said reference signal to produce a correlation signal; and

discrimination means for evaluating the degree of correlation between each of said object signals and said reference signal, a high degree of correlation indicating that said object being viewed is said desired object arranged in the spatial orientation indicated by said object signal under determination.

20. The system of claim 19 wherein said reference generator sequentially generates a plurality of reference signals indicative of a plurality of desired object to be identified;

said correlation means and discrimination means iteratively correlating and evaluating successive combinations of reference and object signals.

21. The system of claim 19 wherein said input means includes a plurality of video monitors and means for multiplexing the outputs produced by said plurality of video monitors.

22. The system of claim 21 wherein said sequentially generated object signals are produced by said video monitors.

23. The system of claim 19 wherein said reference generation means includes;

memory means for storing information representative of said reference signals;

processing means for recalling said information from said memory means and for sequentially producing video signals representative thereof;

display means for converting said video signals into optical reference signals.

24. The system of claim 23 wherein said input means produces optical object signals.

25. The system of claim 24 wherein said input means includes;

a plurality of video monitor means for converting optical impressions of different spatial orientations of said object being viewed into video signals; and

means for converting said at least one video signal into said optical object signals.

26. The system of claim 24 wherein said correlation means includes;

object transform means for optically taking the Fourier transform of each said optical object signal;

reference transform means for optically taking the Fourier transform of said optical reference signal;

combination means for optically adding the Fourier transform of said optical object signal and said optical reference signal to produce an optical sum signal;

squaring means for receiving and optically squaring said sum signal to produce a product signal;

inverse transform means for optically taking the inverse Fourier transform of said optical product signal to produce said correlated signal.

27. The system of claim 26 wherein said discrimination means is implemented with a digital processing computer.

28. The system of claim 27 further comprising:

robotic effector means for manipulating the object being viewed; and

effector control processor means for controlling said robotic effector means to perform a desired task;

said discrimination means, upon detection of a high degree of correlation, providing said effector control processor means with information about said object being viewed necessary to perform said desired task.

29. The system of claim 28 further comprising:

optical to electrical conversion means for converting said optical correlated signal into its electrical counterpart;

said discrimination means detecting the degree of correlation present in the electrical correlated signal.

30. The system of claim 29 further comprising sensor control means for controlling the gain and synchronization of said optical to electrical conversion means.

31. The system of claim 21 further comprising sensor control means for controlling the gain and synchronization of said means for multiplexing.

32. The system of claim 24 further comprising means for generating coherent light;

said display means and input means modulating said coherent light to produce said optical reference signals and optical object signals, respectively.

33. The system of claim 32 wherein said coherent light is modulated in said display means and input means by spatial light modulators.

34. The system of claim 19 wherein said correlation means cross-correlates said object signal and reference signal with parallel optical processing.

35. The system of claim 34 wherein coherent light is used for said parallel optical processing.

36. The system of claim 26 wherein said object transform means, reference transform means, combination means and inverse transform means utilize coherent light.

37. The system of claim 35 or 36 further comprising a laser producing said coherent light.

38. The system of claim 37 further comprising illumination means for lighting said object being viewed, said illumination means including;

means for receiving said coherent light from said laser; and

diffusion means for diffusing said coherent light.

39. A vision system for an industrial robot, said vision system identifying and determining the location and spatial orientation of an object being viewed and comprising:

illumination means for incoherently lighting said object;

input means for viewing said object and producing an object signal indicative of said object as viewed;

coherent modulator means for converting said object signal into a corresponding coherent light object signal;

object optical processing means for taking the Fourier transform of said coherent light object signal;

display means for producing a coherent light reference signal representative of a desired object to be identified;

reference optical processing means for taking the Fourier transform of said coherent light reference signal;

combination means for summing the Fourier transform of said coherent light object signal and that of said coherent light reference signal to produce a sum therebetween;

squaring means for receiving said sum produced by said combination means and squaring said sum to produce a product signal;

inverse transform means for taking the universe Fourier transform of said product signal to produce a cross-correlation signal indicative of the correlation between said object signal and reference signal;

determination means for evaluating the degree of correlation between said object signal and said reference signal, a high degree of correlation indicating that said object being viewed visually corresponds to the desired object to be identified.

41. A method of identifying and determining the location and spatial orientation of an object, said method including the steps of;

viewing said object;

producing an object signal indicative of said object being viewed;

sequentially producing a plurality of reference signals, each indicative of a desired object to be identified and its possible spatial orientation;

cross-correlating said object signal with each sequentially produced reference signal to produce a correlation signal;

determining the degree of correlation between said object signal and each of said reference signals, a high degree of correlation indicating that said object being viewed is said desired object arranged in the spatial orientation of said reference signal.

42. The method of claim 41 wherein the step of sequentially producing a plurality of reference signals includes;

recalling information from a memory indicative of a desired object to be identified and its possible spatial orientation;

producing a video signal from said information;

converting said video signal into an optical reference signal; and

repeating said steps of recalling, sequentially producing and converting to produce a plurality of optical reference signals indicative of different combinations of objects to be identified and then possible spatial orientations.

43. The method of claim 42 wherein said object signal produced is an optical object signal.

44. The method of claim 43 wherein said step of cross-correlating includes the steps of;

optically taking the Fourier transform of said optical object signal;

optically taking the Fourier transform of said optical reference signal;

optically combining said Fourier transforms of said optical object signal and said optical reference signal to produce a combined signal;

optically squaring said combined signal to produce a square signal;

optically taking the inverse Fourier transform of said square signal to produce said correlation signal.

45. The method of claim 44 further comprising the steps of:

manipulating said object being viewed to perform a desired task while utilizing said reference signal.

46. The method of claim 45 further comprising the steps of:

converting said optically correlated signal into its electrical counterpart;

detecting the degree of correlation present in said electrical correlation signal.

47. The method of claim 46 wherein said step of cross-correlating is performed with coherent light.

48. The method of claim 46 wherein said step of cross-correlating utilizes parallel optical processing.

56. The method of claim 46 wherein said step of cross-correlating is performed with coherent light.

57. The method of claim 46 wherein said step of cross-correlating utilizes parallel optical processing.

49. A method of identifying and determining the location and spatial orientation of an object, said method including the steps of:

viewing said object from a plurality of directions and sequentially generating object signals, each indicative of a particular viewed spatial orientation of said object being viewed;

producing a reference signal indicative of a desired object to be identified;

cross-correlating each of said object signals with said reference signal to produce a correlation signal;

determining the degree of correlation between each of said object signals and said reference signal, a high degree of correlation indicating that said object being viewed is said desired object arranged in the spatial orientation indicated by said object signal.

50. The method of claim 49 wherein the step of sequentially producing a plurality of reference signals includes sequentially generating a plurality of reference signals indicative of a plurality of desired objects to be identified.

51. The method of claim 50 wherein said steps of cross-correlating and determining iteratively correlate and evaluate successive combinations of reference and object signals.

52. The method of claim 51 wherein said reference signals and object signals are optical signals.

53. The method of claim 52 wherein said step of cross-correlating includes the steps of:

optically taking the Fourier transform of said optical object signal;

optically taking the Fourier transform of said optical reference signal;

optically combining said Fourier transforms of said optical object signal and said optical reference signal to produce a combined signal;

optically squaring said combined signal to produce a square signal;

optically taking the inverse Fourier transform of said square signal to produce said correlation signal.

54. The method of claim 52 further comprising the steps of:

manipulating said object being viewed to perform a desired task while utilizing said reference signal.

55. The method of claim 54 further comprising the steps of:

converting said optically correlated signal into its electrical counterpart;

detecting the degree of correlation present in said electrical correlation signal.

58. A method of identifying and determining the location and spatial orientation of an object, said method including the steps of:

illuminating said object in incoherent light;

viewing said object and producing an object signal indicative of said object as viewed;

converting said signal into a corresponding coherent light object signal;

taking the Fourier transform of said coherent light object signal;

producing a coherent light reference signal representative of a desired object to be identified;

taking the Fourier transform of said coherent light reference signal;

combining the Fourier transform of said coherent light object signal and that of said coherent light reference signal to produce a sum therebetween;

squaring said sum to produce a product;

taking the inverse Fourier transform of said product to produce a cross-correlation signal indicative of the correlation between said object signal and reference signal;

determining the degree of correlation between said object signal and said reference signal, a high degree of correlation indicating that said object being viewed visually corresponds to the desired object to be identified.