Remote tracking system particularly for moving picture cameras and method

• US 5,179,421 A
• Filed: 08/20/1990
• Issued: 01/12/1993
• Est. Priority Date: 08/20/1990
• Status: Expired due to Term

• Current Assignee: Thomson Licensing SA (Vantiva SA)
• 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:
  US07/569,643
• Time in Patent Office: 876 Days
• Field of Search: 356/28, 356/141, 356/152, 250/203.5, 250/203.3, 358/107, 358/113, 358/125, 318/648
• US Class Current: 356/139.06
• CPC Class Codes: G01C 1/00 Measuring angles
• CPC Class Codes: G01S 3/783 using amplitude comparison of signals derived from static detectors or detector systems
• CPC Class Codes: G01S 3/786 the desired condition being maintained automatically

Abstract

The system includes a base unit sensitive to infrared (IR) signals transmitted by a mobile remote unit to an IR receiver which is placed behind a rotating set of signal blocking blinders whose position at any time defines a view angle with a position known with precision resulting in the IR signal reception scanning across an area. The base unit detects when the peak strength of the signal occurs and utilizes this data to determine the exact effective angle between the axis of the IR signal and the base unit to create an error signal used by the base unit to position the camera mounted thereon. Receivers 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 the base unit.

Claims

1. A method of calculating the angular displacement of an object with respect to a reference angle and moving a movable means to track the object in response thereto comprising:

A. transmitting at the location of the object a signal from a radiant energy source into an area;

B. scanning the area, independently of moving the movable means, for the transmitted signal by varying the view angle through which the transmitted signal can be received during a time interval;

C. receiving by a receiver the transmitted signal through the view angle;

D. determining the point in the time interval at which each angular position of the view angle occurs during the time interval;

E. computing the angular displacement of the object with respect to the reference angle by comparing the point in the time interval at which the receiver received the transmitted signal with the angular position of the view angle through which the signal was received with respect to the same point in the time interval; and

F. moving the movable means, independently of scanning the area, in response to the results obtained in step E to track the object.

2. The method of claim 1 wherein step B includes the steps of:

G. placing a pair of spaced blinders between the transmitter and the receiver;

H. receiving the signal through the space between the pair of blinders; and

I. moving the pair of blinders with respect to the transmitter to vary the position at which a predetermined level of the signal strength transmitted can be received through the area during the time interval.

3. The method of claim 2 wherein step D includes the step of:

J. detecting the position of the blinders during the time interval.

4. The method of claim 1 wherein step B includes the step of:

G. scanning the area substantially in the horizontal plane.

5. The method of claim 1 wherein step B includes the step of:

G. scanning the area substantially in the vertical plane.

6. The method of claim 1 wherein step B includes the step of:

G. scanning the area substantially in the horizontal and vertical planes.

7. The method of claim 1 further including the step of:

G. providing an output signal indicative of the calculated angular displacement.

8. A method of tracking a movable object by repetitively calculating the angular displacement of the object with respect to a reference angle and moving a movable means to track the object in response thereto comprising the steps of:

A. transmitting at the location of the object a signal from a source of radiant energy of the electromagnetic spectrum into an area;

B. repetitively scanning an area containing the object for the transmitted signal by varying the view angle through which the signal can be received during successive time intervals;

C. repetitively detecting at the receiver the transmitted signal;

D. providing a data signal indicative of the time at which the transmitted signal was received at the receiver;

E. determining the point in each time interval at which each angular position of the signal occurs with respect to a reference position during that time interval;

F. repetetively computing the angular displacement of the object with respect to the reference position by repetitively comparing the point in each of a series of time intervals at which the receiver received the signal with the angular position of the view angle with respect to the same point in the corresponding time interval;

G. computing the direction of movement of the object by successively comparing the calculated angular displacements of the object during the series of time intervals; and

H. moving the movable means to track the object in response to the results obtained in step G.

9. The method of claim 8 wherein step G includes the steps of:

I. determining the real time between successive angular displacement calculations; and

J. computing the rate of movement of the object in real time by calculating the rate of change of the angular displacement of the object during successive time intervals.

10. The method of claim 8 wherein step B includes the steps of:

I. placing a movable pair of spaced blinders between the radiant energy source and the object;

J. receiving the signal through the space between the blinders; and

K. repetitively moving the pair of blinders with respect to the radiant energy source for varying the position of the view angle through which a predetermined level of the signal strength transmitted can be received through the area during each of a series of successive corresponding time intervals.

11. The method of claim 10 wherein step E includes the step of:

L. detecting the position of the pair of blinders during each time interval.

12. The method of claim 10 further including the steps of:

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

M. providing a second output signal indicative of the direction of movement of the object with respect to the reference angle.

13. The method of claim 9 wherein step I includes the step of:

K. providing a first output signal indicative of the rate of movement of the object with respect to the reference angle.

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

A. transmitting at the position of the object a signal from a source of radiant energy of the electromagnetic spectrum into an area;

B. repetitively scanning an area containing the object, independently of moving the camera, by varying the position of the view angle through which the signal can be received through the area in substantially the horizontal plane and in substantially the vertical plane and each through a series of time intervals;

C. repetitively detecting by horizontal and vertical receivers the transmitted signal which is transmitted from the object;

D. providing a first and second data signal indicative of the time at which the signal was received by the respective receivers;

E. determining the point in each time interval at which the angular position of each view angle occurs with respect to a reference position during each time interval;

F. repetitively computing the angular displacement of the object with respect to the reference position in the horizontal and vertical planes by repetetively comparing the results of steps D and E;

G. 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

H. operating the movable means and the camera attached thereto independently of scanning an area in accordance with the results obtained in step G.

15. The method of claim 14 wherein step F includes the steps of:

I. 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;

J. 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

K. moving the movable means with a camera attached thereto in response to the first and second 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.

16. A system for calculating angular displacement of two objects with respect to a reference position comprising a base unit and a remote unit, said remote unit having a transmitter means for transmitting a transmitted signal, said base unit having receiver means including reception direction control means for varying the angular displacement of the signal direction at which said transmitted signal can be received by said receiver means during a time interval with respect to a reference angle as established by said reception direction control means, said reception direction control means including means including position detecting means for providing a position output signal representative of said signal direction with respect to said reference angle during said time interval, said receiver means being responsive to said transmitted signal and providing a receiver output signal in response to receiving said transmitted signal at said signal direction, said receiver means further providing a first output signal in response to said receiver output control signal, said base unit further including control circuit means responsive to said position output signal and said first output signal for determining the angular displacement of said signal direction of said transmitted signal from said reference angle and for determining the angular displacement between said reference angle and said signal direction at the time said transmitted signal was receive by said receiver means and providing an error output signal indicative of said angular displacement, said base unit further including movable means responsive to said error output signal for moving said base unit in response to said error output signal, said reception direction control means being movable while varying said angular displacement of the signal direction independently of moving said movable means.

17. The system as defined in claim 16 wherein said position output signal provided by said position detecting means is representative of an angular displacement of said signal direction from a reference angle.

18. The system as defined in claim 17 wherein said receiver means is responsive to the strength of said transmitted signal and provides said receiver output signal in response to the strength of said transmitted signal, said receiver circuit 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 control circuit means determining said position of said signal direction at the time when said receiver means receives said predetermined level of signal strength of said transmitted signal.

19. The system as defined in claim 16 wherein said first transmitter means includes a source of radiant energy of the electromagnetic spectrum.

20. In the system as defined in claim 18 wherein said predetermined level of the signal strength of said first transmitted signal is the maximum level.

21. A method of recording pictures by a camera mounted on a tracking unit having a movable portion comprising the steps of:

A. providing a camera and tracking unit movable in at least one plane;

B. providing a device detectable by the tracking unit by the emission of radiant energy of the electromagnetic spectrum by the device;

C. employing the device by a user who will be in the picture frame of the camera;

D. detecting the device by a receiver of the tracking unit as the user moves with such device to operate the movable portion of the tracking unit which correspondingly moves the camera to maintain the device in the picture frame; and

E. providing a means for varying the view angle of the receiver, independently of the movable portion of the tracking unit and the field of view of the camera, through which the receiver can detect the radiant energy from the device.

22. The method of claim 21 wherein step A includes the step of:

p1 E. providing a tracking unit movable in two substantially perpendicular planes.

23. The method of claim 21 wherein step D includes the step of:

E. repeating step D during successive time intervals to cause the camera to follow the device.

24. The method of claim 21 wherein step A includes the step of:

F. providing a tracking unit that is movable in two planes.

25. The method of claim 21 wherein step B includes the step of:

F. providing an infrared signal.

26. In a system for determining the location of an object relative to a reference position and moving a movable means to track an object in response thereto;

transmitter means co-located with said object for producing a radiant energy signal of the electromagnetic spectrum;

receiver means located at said reference position and having a narrow angle of reception for producing a detection signal in response to irradiation of said receiver means by said radiant energy signal;

scanning means, movable independently of said movable means, for moving said angle of reception of said receiver means through a predefined area in which said object is located; and

sensing means responsive to said detection signal for sensing the position of said angle of reception in said predefined area, thereby establishing the location of said object and producing a sensing output signal in response to the sensed position, and moving said movable means, independently of said scanning means, in response thereto to track said object.

27. The system as defined in claim 26 further including a camera and a tracking unit movable in at least one plane and being operatively connected to said sensing means for moving said camera and said tracking unit to maintain said object in the picture frame of said camera.

28. The system as defined in claim 27 wherein said transmitter means and said object are adapted to be held by a user for maintaining a user in the picture frame of said camera when a user is holding said transmitter and said object.

29. The system as defined in claim 27 wherein said tracking unit is movable in two substantially perpendicular planes.

30. The system as defined in claim 27 wherein said object is a hand-held microphone.

31. The system as defined in claim 27 wherein said transmitter means is mounted to a hand-held microphone.

32. The system as defined in claim 27 wherein said scanning means moves said angle of reception during successive time intervals, said tracking unit being continuously movable to maintain said object and said transmitter means in the picture frame of said camera.

33. A method for determining the location of an object relative to a reference position and moving a movable means to track the object in response thereto comprising the steps of:

A. transmitting from the location of the object a radiant energy signal of the electromagnetic spectrum;

B. providing a receiver at said reference position which has a narrow reception angle and which produces a detection signal in response to being irradiated by the radiant energy;

C. moving the reception angle, independently of moving the movable means, through a predefined area in which the object is located;

D. determining the location of the object in the predefined area in response to irradiation of said receiver by the radiant energy signal; and

E. moving the movable means, independently of moving the reception angle, in response to the results obtained in step D to track the object.

34. The method of claim 33 wherein step B includes the steps of:

F. providing a camera and tracking unit movable in at least one plane;

G. providing the receiver to be held by a user which will be in the picture frame of the camera; and

H. tracking the receiver by the tracking unit as the user moves with the receiver to operate the tracking unit which correspondingly moves the camera to maintain the user in the picture frame.

35. The method of claim 33 wherein step B includes the step of:

F. mounting the receiver in a hand-held microphone.

36. A system for calculating angular displacement of two objects with respect to a reference position comprising a base unit and a remote unit, said remote unit having a first transmitter means for transmitting a first transmitted signal, said base unit having first receiver means including view angle control means for varying the angular displacement of the position of the view angle through which said first transmitted signal can be received by said receiver means during first time interval with respect to a reference angle as established by said view angle control means, said view angle control means including position detecting means for providing a position output signal representative of said position of said view angle with respect to a reference angle during said first time interval, said first receiver means further providing a first output in response to said receiver output signal, said base unit further including control circuit means responsive to said position output signal and said first output signal for determining the angular displacement between said reference angle and said view angle at the time said first transmitted signal was received by said first receiver means and providing an error output signal indicative of said angular displacement, said base unit further including movable means responsive to said error output signal for moving said base unit in response to said error output signal, said view angle control means being movable while varying the angular displacement of the position of the view angle independently of moving said movable means.

37. The system as defined in claim 36 wherein said view angle control means includes a pair of spaced movable signal blocking means positioned between said first transmitter means and said first receiver means, and defining said view angle therebetween, said first receiver means receiving said first transmitted signal through said view angle, said view angle control means including mechanical means for repetitive movement of said movable signal blocking means with respect to said first transmitter means for varying the angular orientation of said view angle of said first transmitted signal in response to movement of said signal blocking means.

38. The system as defined in claim 37 wherein said first transmitter means includes an infrared signal source.

39. The system as defined in claim 38 wherein said position detecting means is responsive to the movement of said view angle for providing said position output signal indicative of the position of said view angle with respect to said reference angle.

40. The system as defined in claim 36 wherein said first transmitter means includes a source of radiant energy of the electromagnetic spectrum.

41. The system as defined in claim 36 wherein said view angle control mean varies the angular displacement of the position of said view angle in a substantially horizontal plane.

42. The system as defined in claim 36 wherein said view angle control mean varies the angular displacement of the position of said view angle in a substantially vertical plane.

43. A system for calculating angular displacement of two objects with respect to a reference position comprising a base unit and a remote unit having a first transmitter means for transmitting a first transmitted signal, said base unit having first receiver means including view angle control means for varying the angular displacement of the position of the view angle through which said first transmitted signal can be received by said receiver means during a first time interval with respect to a reference angle as established by said view angle control means, said view angle control means including position detecting means for providing a position output signal representative of said position of said view angle with respect to a reference angle during said first time interval, said first receiver means being responsive to said first transmitted signal and providing a receiver output signal in response to having received said first transmitted signal through said view angle, said first receiver means further providing a first output signal in response to said receiver output signal, said base unit further including control circuit means responsive to said position output signal for determining the angular displacement between said reference angle and said view angle at the time said first transmitted signal was received by said first receiver means and providing an error output signal indicative of said angular displacement, said position detecting means produces said position output signal so that it is representative of an angular displacement of said view angle from a reference angle and said first receiver means is responsive to the strength of said first transmitted signal, said receiver circuit 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 control circuit means determining said position of said view angle at the time when said first receiver means receives said predetermined level of signal strength of said first transmitted signal, said base unit further including movable means responsive to said error output signal for moving said base unit in response to said error output signal for moving said base unit in response to said error output signal, said view angle control means being movable while varying said angular displacement independently of moving said movable means.

44. The system as defined in claim 43 wherein said predetermined level of the signal strength of said first transmitted signal is the maximum level.

45. A system for calculating angular displacement of two objects with respect to a reference position comprising a base unit and a remote unit, said remote unit having a first transmitter means for transmitting a first transmitted signal, said base unit having first receiver means including view angle control means for varying the angular displacement of the position of the view angle through which said first transmitted signal can be received by said receiver means during a first time interval with respect to a reference angle as established by said view angle control means, said view angle control means including position detecting means for providing a position output signal representative of said position of said view angle with respect to a reference angle during said first time interval, said first receiver means being responsive to said first transmitted signal and providing a receiver output signal in response to having received said first transmitted signal through said view angle, said first receiver means further providing a first output signal in response to said receiver output signal, said base unit further including control circuit means responsive to said position output signal and said first output signal for determining the angular displacement of the position of said first transmitted signal from said reference angle and for determining by calculation the angular displacement between said reference angle and said view angle at the time said first transmitted signal was received by said first receiver means and providing an error output signal indicative of said angular, said control circuit means including 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.

46. The system as defined in claim 45 wherein said control circuit means includes means for determining the real time of successive angular displacements of said remote unit for determining the rate of directional movement of said remote unit with respect to said base unit.

47. The system as defined in claim 45 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.

48. The system as defined in claim 47 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.

49. The system as defined in claim 48 wherein a first of said command signals when selected will allow said control circuit means to provide said error output signal to said movable means.

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

51. A method of recording pictures by a camera comprising the steps of:

A. providing a means for moving the field of view of the camera in at least one plane for tracking an object to be recorded by the camera;

B. providing a means for emitting radiant energy of the electromagnetic spectrum;

C. locating the means for emitting the radiant energy in a known relationship to an object to be tracked by the camera;

D. providing a receiver means for detecting the location of the radiant energy from the means for emitting;

E. providing a means for varying the view angle of the receiver through which the receiver can detect the radiant energy from the means for emitting the energy;

F. providing a means for determining the difference in position between the location of the radiant energy and the field of view; and

G. moving the camera field of view independently of varying the view angle to eliminate any difference in position between the location of the radiant energy and the field of view.