Remote tracking system for moving picture cameras and method

• US 5,268,734 A
• Filed: 05/31/1990
• Issued: 12/07/1993
• Est. Priority Date: 05/31/1990
• Status: Expired due to Term

• Current Assignee: Gvbb Holdings SARL (Vislink Technologies, Inc.)
• Original Assignee: ParkerVision, Inc.
• Inventors: Sorrells, David F., Parker, Jeffrey L., Mix, John D., Daber, Richard P.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US07/530,999
• Time in Patent Office: 1,286 Days
• Field of Search: 356/APS 1, 356/141, 356/152, 356/4, 358/107, 358/113, 358/125, 250/206.1, 250/206.2, 250/203.5, 250/203.3, 352/APS 53, 352/197, 352/243, 342/37, 342/51, 318/640
• US Class Current: 356/139.06
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: H04N 23/661 Transmitting camera control signals through networks, e.g. control via the Internet
• CPC Class Codes: H04N 23/695 Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects

Abstract

The system includes a mobile remote unit sensitive to infrared (IR) signals transmitted by a base or stationary unit and an IR transmitter which is placed behind a rotating lens whose position at any time is known with precision resulting in the IR signal being "scanned" across an area. The remote unit detects when the peak strength of the signal occurs and provides this data via an RF signal to the base unit wherein the exact effective angle between the axis of the IR signal and the remote unit creates an error signal used by the base unit to position the camera mounted thereon. Transmitters for TILT and two PAN positions, PAN 1 and PAN 2, are used to include range calculations for ZOOM functions. Command circuitry to override the automatic tracking function is provided in each of the units.

Claims

1. A system for calculating the angular displacement of two objects with respect to a reference position for controlling the field of view of a camera comprising:

a base unit and a movable remote unit, said base unit having a first transmitter means for transmitting a first transmitted signal, said first transmitter means including signal positioning means for varying the angular displacement of the position of said first transmitted signal with respect to a reference angle as established by said signal positioning means, said signal positioning means including position detecting means for providing a position output signal representative of said position of said first transmitted signal, said remote unit including first receiver means responsive to said first transmitted signal and providing a receiver output signal in response to having received said first transmitted signal, said first receiver means providing a first output signal in response to said receiver output signal, said remote unit further including second transmitter means for transmitting a second transmitted signal, said second transmitter means responsive to said first output signal for providing in said second transmitted signal an information signal indicative of said receiver output signal having been received, said base unit further including second receiver means responsive to said second transmitted signal for providing a second output signal indicative of said first output signal, said base unit further including control circuit means responsive to said position output signal and said second output signal for determining the angular displacement of the position of said first transmitted signal and for determining the angular displacement between said reference angle and said first receiver means and providing an error output signal indicative of said angular displacement, and means for controlling the field of view of a camera in response to said error output signal.

2. The system as defined in claim 1 wherein said signal positioning means varies the angular displacement of said position of said first transmitted signal by varying the angular displacement of the position of a predetermined level of the signal strength of said first transmitted signal with respect to said reference angle.

3. The system as defined in claim 2 wherein said position output signal provided by said position detecting means is representative of the angular displacement of said predetermined level of signal strength.

4. The system as defined in claim 3 wherein said first receiver means is responsive to the strength of said first transmitted signal and provides said receiver output signal in response to the strength of said first transmitted signal, said first receiver means including signal strength detection circuit means for determining the relative strength of said receiver output signal and providing said first output signal when said receiver output signal is at a predetermined level as established by said signal strength detection circuit means, said second transmitter means providing said information signal indicative of the strength of said receiver output signal being at said predetermined level, said control circuit means determining said position of said predetermined level of signal strength and receiving said information signal at a time when said first receiver means receives said predetermined level of signal strength of said first transmitted signal for determining location of said second transmitter means.

5. The system as defined in claim 2 wherein said signal positioning means includes a movable lens positioned between said first transmitter means and said receiver, said first transmitter, means transmitting said first transmitted signal through said lens, said signal positioning means including mechanical means for repetitive movement of said movable lens with respect to said first transmitter means for varying the angle at which the signal strength of said first transmitted signal is at said predetermined level in response to movement of said lens.

6. The system as defined in claim 5 wherein said first transmitter means includes an infrared signal source.

7. The system as defined in claim 6 wherein said position detecting means is responsive to the movement of said lens for providing said position output signal indicative of the position of said lens with respect to said reference angle.

8. The system as defined in claim 7 wherein said second transmitted signal is a radio frequency signal.

9. The system as defined in claim 1 wherein said first transmitter means includes a source of electromagnetic energy.

10. The system as defined in claim 1 wherein said second transmitted signal is a radio frequency signal.

11. The system as defined in claim 2 wherein said predetermined level of the signal strength of said first transmitted signal is the maximum level.

12. The system as defined in claim 1 wherein said signal positioning means varies the angular displacement of said predetermined level of the signal strength in a substantially horizontal plane.

13. The system as defined in claim 1 wherein said signal positioning means varies the angular displacement of said predetermined level of the signal strength in a substantially vertical plane.

14. The system as defined in claim 1 wherein said control circuit means includes means for comparing one said error output signal indicative of one said angular displacement with a successive said error output signal indicative of a successive said angular displacement for determining the directional movement of said remote unit with respect to said base unit.

15. The system as defined in claim 14 wherein said control circuit means includes means for determining the real time of successive said angular displacements of said remote unit for determining the rate of directional movement of said remote unit with respect to said base unit.

16. The system as defined in claim 1 wherein said base unit includes movable means responsive to said error output signal for moving said base unit in response to said error output signal.

17. The system as defined in claim 14 wherein said base unit includes movable means responsive to each said error output signal for moving said base unit as determined by said error output signal.

18. The system as defined in claim 17 wherein said base unit includes command circuit means for selectively providing a plurality of command signals to said control circuit means for selectively altering said error output signal provided from said control circuit means to said movable means for selectively controlling the movement of said base unit in response to said error signals.

19. The system as defined in claim 18 further comprising means responsive to a first said command signal when selected for enabling said control circuit means to provide said error output signal to said movable means.

20. The system as defined in claim 18 further comprising means responsive to a first said command signal when selected for preventing said control circuit means from providing said error output signal to said movable means.

21. The system as defined in claim 18 further comprising means responsive to a first said command signal when selected for altering said error output signal by an angular deviation from said angular displacement determined by said error output signal, defining an offset angle.

22. The system as defined in claim 7 wherein said first return signal is a radio frequency signal.

23. The system as defined in claim 1 wherein said signal transmitter means includes a source of electromagnetic energy.

24. A system for calculating the angular displacement of one object with respect to another for controlling the field of view of a camera comprising a base station in a known position with respect to one object and a movable remote unit in a known position with respect to another object, said base station including a first transmitter assembly having first transmitter means for transmitting a first scanning signal and including signal positioning means for scanning an area in a plane with said first scanning signal and having position indicating means for providing a first output signal indicative of the position of said first scanning signal, said remote unit having a receiver circuit means for detecting the passage of said scanning signal across said remote unit and providing a signal detected output signal when said first scanning signal is received, first remote transmitter means responsive to said signal detected output signal for transmitting a first return signal which includes information indicating that said first scanning signal was received, said base station further including circuit means responsive to said first output signal and said first return signal for determining the relative position of said remote unit with respect to said base station by determining the position of said first scanning signal when said receiver circuit means receives said first scanning signal across said remote unit and providing a control output signal indicative of the angular displacement of said remote unit with respect to said base station, and means for controlling the field of view of a camera in response to said control output signal.

25. The system as defined in claim 24 wherein said signal positioning means includes a movable lens positioned between said first transmitter means and said receiver circuit means, said first transmitter means transmitting said first scanning signal through said lens, said signal positioning means including mechanical means for repetitive movement of said lens with respect to said first transmitter means for repetitively varying the angle of said first scanning signal in response to movement of said lens for repetitively scanning an area with said scanning signal.

26. The system as defined in claim 24 wherein said signal positioning means includes a movable lens, said first transmitter means positioned to transmit said first scanning signal through said lens, said signal positioning means further including mechanical means for repetitive movement of said

lens with respect to said first transmitter means for varying the angle at which the signal strength of said first scanning signal is at a maximum value in response to movement of said lens during successive time intervals for scanning an area with said scanning signal during respective said successive time intervals.

27. The system as defined in claim 26 wherein said circuit means includes means for determining the direction said remote unit is moving with respect to said base station by successively determining the position of said scanning signal at the time said receiver circuit means receives said scanning signal across said remote unit during a series of said time intervals and for providing a second control output signal indicative of said direction of movement.

28. The system as defined in claim 27 wherein said base station includes movable means responsive to said first and second control output signals for moving said base station in response to said control output signals.

29. The system as defined in claim 26 wherein said circuit means includes means for determining the direction and speed of movement of said remote unit with respect to said base station by successively determining the position of said first scanning signal at the time said receiver circuit means receives said scanning signal across said remote unit during a series of said time intervals, means including second means for determining the real time of successive determinations of position of said remote unit for determining the rate of directional movement of said remote unit with respect to said base station and providing a second control output signal indicative of said rate and direction of movement.

30. The system as defined in claim 29 wherein said base station includes movable means responsive to said first and second control output signals for moving said base station in response to said control output signals.

31. The system as defined in claim 30 wherein said circuit means includes command signal circuit means for selectively enabling and disabling said first and second control output signals for selectively controlling the response of said movable means to said control output signals.

32. Apparatus for determining the location of a first object with reference to a second object comprising a base unit in a known position with respect to the second object and a remote unit in a known position with respect to said first object and both said remote unit and said first object being movable in at least two dimensions, said apparatus including a pair of systems for determining the angular displacement of a said remote unit with respect to said base unit, said pair of systems including a first said system for determining the angular displacement of a said remote unit with respect to said base unit in the horizontal plane and a second said system for determining the angular displacement of a said remote unit with respect to said base unit in the vertical plane, each said system including a signal transmitter means for transmitting a scanning signal, said signal transmitter means including signal positioning means for varying the displacement of the position of said scanning signal in a plane during a time interval with respect to a reference angle as established by said signal positioning means, said signal transmitter means further including position indicating means for providing a first output signal indicative of the position of said scanning signal continuously during said time interval, signal receiver means for receiving said scanning signal across said receiver means and providing a signal detected output signal in response to the receiving of said scanning signal by said receiver means, return signal transmission means responsive to said signal detected output signal for transmitting a first return signal which includes a first information signal indicating that said scanning signal was received by said receiver means, return signal receiver means responsive to said first return signal and providing a second output signal indicative of said scanning signal being received by said signal receiver means, control circuit means responsive to said first and second output signals for determining the relative position of said signal receiver means with respect to said reference angle by determining the position of said scanning signal at the time said signal receiver means receives said scanning signal during said time interval and providing a first error control signal indicative of the angular displacement of said signal receiver means with respect to said reference angle in respective said plane.

33. The apparatus as defined in claim 32 wherein said signal receiver means includes a single signal receiver circuit means common to both said systems.

34. The apparatus as defined in claim 32 wherein said signal receiver means includes a signal receiver circuit means for each said system.

35. The apparatus as defined in claim 32 wherein said base unit includes said signal transmitter means, said return receiver means and said control circuit means for each said system,

said remote unit includes said signal receiver means and said return signal transmission means for each said system.

36. The apparatus as defined in claim 35 wherein each said signal positioning means includes a movable lens, said respective signal transmitter means positioned to transmit said scanning signal through said lens, said signal positioning means further including mechanical means for repetitive movement of said lens with respect to said transmitter means for varying the angle of said scanning signal in response to movement of said lens during successive time intervals for scanning an area in a plane with said scanning signal during respective said time intervals.

37. The apparatus as defined in claim 36 wherein said control circuit means includes computational circuit means for determining the directional movement of a said remote unit in a said plane wit respect to said base unit by successive comparison of a said first error control signal indicative of the angular displacement in said plane of said remote unit during one respective said time interval with another said first error control signal during another said time interval and providing a second error control signal indicative of said directional movement.

38. The apparatus as defined in claim 37 wherein said computational circuit means includes clock means for determining the real time of successive comparisons for computing the rate of said directional movement of said remote unit, said control circuit means providing a third error control signal indicative of said rate of directional movement.

39. The apparatus as defined in claim 37 wherein said computational circuit means includes circuit means for distance determination of a said remote unit from said base unit, said circuit means having data indicative of the distance between respective said signal transmitter means in said systems and being responsive to error control signals from said first and second systems and providing a third error control signal indicative of said distance determination.

40. The apparatus as defined in claim 37 wherein said base unit includes movable means responsive to said first and second error control signals from each said system for moving said base unit in response to said error control signals.

41. The apparatus as defined in claim 38 wherein said base unit includes movable means, said movable means being responsive to said third error control signals from each said system for moving said base unit in response to said rate of directional movement.

42. The apparatus as defined in claim 37 wherein the second object includes a camera having a visual lens, said base unit further including movable means responsive to said first and second error control signals from each said system for moving said camera in response to respective said error control signals.

43. The apparatus as defined in claim 37 wherein the second object includes a camera having a visual lens, said base unit further including movable means responsive to said first, second and third error control signals from each said system for moving said camera in response to respective said error control signals.

44. The apparatus as defined in claim 39 wherein the second includes a camera having an adjustable zoom lens and zoom control means for selectively adjusting said lens, said base unit further including movable means responsive to said first, second and third error control signals from each said system for moving said camera in response to respective said error control signals and for supplying a zoom control signal to said zoom control means for selective adjustment of said lens in response to said distance determination.

45. The apparatus as defined in claim 32 further comprising signal transmitter control circuit means for providing alternating transmitter control signals to each respective said signal transmitter means for causing one said respective signal transmitter means transmit said scanning signal from one respective said system before the transmission of said scanning signal from the other said system and continue said transmissions in an alternating manner.

46. The system as defined in claim 40, wherein said base unit includes command circuit means for selectively providing a plurality of command signals to said control circuit means for selectively controlling said error output signal provided from said control circuit means to sad movable means for selectively controlling the movement of said base unit in response to said error signals.

47. The system as defined in claim 46 wherein a first said command signal when selected will allow said control circuit means to provide said error output signals to said movable means.

48. The system as defined in claim 46 wherein a first said command signal when selected will prevent said control circuit means from providing said error output signals to said movable means.

49. The system as defined in claim 46 wherein a first said command signal when selected will alter said first error output signal by an angular deviation from said angular displacement determined by said error output signal, defining an offset angle.

50. The system as defined in claim 32 wherein said first output signal provided by respective said position detecting means is representative of the angular displacement of respective said signal.

51. The system as defined in claim 50 wherein said signal receiver means is responsive to the strength of said scanning signal and provides said signal detected output signal in response to the strength of said scanning signal, said signal receiver means including signal strength detection circuit means for determining the relative strength of said signal detected output signal and providing said signal detected output signal when said signal detected output signal is at a predetermined level as established by said signal strength detection circuit means, said second transmitter means providing said first information signal indicative of the strength of said signal detected output signal being at said predetermined level, said control circuit means determining said position of said scanning signal and receiving said information signal at a time when said signal receiver means receives said predetermined level of signal strength of said scanning signal for determining location of said return signal transmission means.

52. The system as defined in claim 51 wherein said signal transmitter means in each said system includes an infrared signal source.

53. The system as defined in claim 36 wherein said position detecting means is responsive to the movement of said lens for providing said first output signal indicative of the position of said lens with respect to said reference angle.

54. The system as defined in claim 32 wherein said first return signal is a radio frequency signal.

55. In the system as defined in claim 51 wherein said predetermined level of the signal strength of said first transmitted signal is the maximum level.

56. In the system as defined in claim 50 wherein one said signal positioning means varies the angular displacement of said signal in a substantially horizontal plane.

57. In the system as defined in claim 50 wherein one said signal positioning means varies the angular displacement of said signal in a substantially vertical plane.

58. A method of tracking a movable object with a camera mounted on a movable means for moving the camera by determining the location of the object with respect to a reference position comprising the steps of:

A. scanning an area containing the object with a first and second transmitted signal from a respective first and second electromagnetic energy source by varying the position of the signal through the area in substantially the horizontal plane with the first signal and in substantially the vertical plane with the second signal;

B. receiving at the object the transmitted signals;

C. providing a first and second signal indicative of the time at which the first and second transmitted signals were received at the object;

D. computing the angular displacement of the object with respect to the reference position in the horizontal and vertical planes by repetitively comparing the result of step C;

E. computing the direction of movement of the object in the horizontal and vertical planes by successively comparing the calculated angular displacements of the object in each plane; and

F. moving the camera in accordance with the results obtained in step E.

59. The method of claim 58 wherein step D includes the steps of:

G. providing a first output signal indicative of the angular displacement of the object from the reference position in the horizontal plane to the movable means;

H. providing a second output signal indicative of the angular displacement of the object from the reference position in the vertical plane to the movable means; and

I. moving the camera by the movable means in response to the output signals to alter the angular displacement of the object from the reference position in either one or both of the horizontal and vertical planes.

60. The method of claim 58 wherein step E includes the steps of:

G. determining the real time between successive displacement calculations in both planes; and

H. computing the rate of movement of the object in both planes in real time by calculating the rate of change of the displacement of the object during successive time intervals.

63. The method of claim 59 further including the step of:

G. selectively modifying the output signals by an amount equal to a desired offset angle to provide for tracking of a point that is displaced angularly by the selected offset angle from the object.

61. The method of 58 further including the steps of:

G. providing a first output signal indicative of each of the calculated angular displacements; and

H. providing a second output signal indicative of the direction of movement of the object in each plane with respect to the reference angle.

62. The method of claim 61 wherein step H includes the step of:

I. providing output signals indicative of the rate of movement of the object in each plane with respect to the reference angle.

64. A method of positioning a camera that is movable by a command-driven controller having memory to track a position that is offset from a movable object comprising the steps of:

A. placing the object in a reference position in the field of view of the camera;

B. providing a command to the controller indicating that the object is in the reference position in accordance with step A;

C. repositioning the object to another desired position angularly offset from the reference position;

D. providing a second command to the controller indicating that the object is positioned in the other desired position in accordance with step C; and

E. providing a third command to the controller to operate the controller for maintaining the camera pointed at the object angularly offset by the angular displacement between the reference position and the other desired position regardless of the position of the object.

65. The method of claim 64 wherein step A includes the step of positioning the object in the center of the field of view.

66. A system for determining the actual angular location of an object relative to a reference position for controlling the field of view of a camera including first transmitter means disposed at said reference position for generating an electromagnetic energy signal elongated in a predetermined direction, scanning means for moving said signal in a direction substantially perpendicular to said predetermined direction, first means in a known relationship with respect to said object responsive to irradiation with respect to said object responsive to irradiation by said signal and generating an output signal indicative of an alignment of said first signal relative to said object, means responsive to said output signal for determining the location of said signal to establish the actual angular location of the object, and means to control the field of view of a camera in response to the established actual angular location of the object.

67. Apparatus for determining the location of a first object with reference to a second object comprising a base unit in a known position with respect to the second object and ar emote unit in a known position with resect to said first object and both said remote unit and said first object being movable in at least two dimensions, said apparatus including a pair of systems for determining the angular displacement of a said remote unit with respect to said base unit, said pair of systems including a first said system for determining the angular displacement of a said remote unit with respect to said base unit in the horizontal plane and a second said system for determining the angular displacement of a said remote unit with respect to said base unit in the vertical plane, each said system including a signal transmitter means for transmitting a scanning signal, said signal transmitter means including signal positioning means for varying the displacement of the position of said scanning signal in a plane with respect to a reference angle as established by said signal positioning means, said signal transmitter means further including position indicating means for providing a first output signal indicative of the position of said scanning signal, signal receiver means for detecting the passage of said scanning signal across said receiver means and providing a signal detected output signal in response to the detection of said scanning signal by said receiver means, return signal transmission means responsive to said signal detected output signal for transmitting a first return signal which includes a first information signal indicating that said scanning signal was detected by said receiver means, return signal receiver means responsive to said first return signal and providing a second output signal indicative of said scanning signal being detected by said signal receiver means, control circuit means responsive to said first and second output signals for determining the relative position of said signal receiver means with respect to said reference angle by determining the position of said scanning signal at the time said signal receiver means detects said scanning signal and providing a fist error control signal indicative of the angular displacement of said signal receiver means with respect to said reference angle in respective said plane.

68. A method of calculating the angular displacement of one object in two planes with respect to a reference angle comprising the steps of:

A. scanning an area in two planes containing the object with a transmitted signal from a location from an electromagnetic energy source by varying the position of the signal through the area;

B. detecting at the object the transmitted signal received at the object;

C. generating a signal from the object indicative of an alignment of the transmitted signal relative to the object and transmitting the signal; and

D. receiving the transmitted signal from step C and computing the angular displacement of the object in two planes with respect to the reference angle.

69. A method of tracking a movable object with a camera mounted on a movable means for moving the camera by determining the location of the object with respect to a reference position comprising the steps of:

A. scanning an area containing the object with a first transmitted signal from a first electromagnetic energy source by varying the position of the signal through the area in a first plane with the first signal;

B. detecting at the object the first transmitted signal which is received a the object;

C. providing a first signal indicative of the time at which the first transmitted signal was received at the object;

D. computing the angular displacement of the object with respect to the reference position in the plane by comparing the results of step C;

E. computing the direction of movement of the object in the plane by successively comparing the calculated angular displacements of the object; and

F. moving the camera in accordance with the results obtained in step E.

70. The method of claim 69 further including the steps of:

G. scanning the area with a second transmitted signal from a second electromagnetic energy source by varying the position of the signal through the area in another plane;

H. detecting at the object the second transmitted signal which is received at the object;

I. providing a second signal indicative of the time at which the second transmitted signal was received at the object;

J. computing the angular displacement of the object with respect to the reference angle in the second plane by comparing the results obtained in step I; and

K. repeating steps E and F for the direction of movement and moving the camera in the second plane.