Remote tracking system for moving picture cameras and method

• US 5,465,144 A
• Filed: 10/19/1994
• Issued: 11/07/1995
• Est. Priority Date: 05/31/1990
• Status: Expired due to Term

• Current Assignee: Gvbb Holdings SARL (Vislink Technologies, Inc.)
• Original Assignee: ParkerVision, Inc.
• Inventors: Parker, Jeffrey L., Sorrells, David F., Mix, John D., Daber, Richard P.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US08/326,069
• Time in Patent Office: 384 Days
• Field of Search: 356/141.1, 356/139.06, 318/640, 318/648, 250/206.1, 250/206.2, 250/206.3, 352/53, 352/197, 352/243
• 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 method of calculating the angular displacement of one object with respect to a reference position in a camera control system comprising the steps of:

A. scanning an area containing the object with a first transmitted signal from a location having a continuous infrared energy source by varying the position of the signal through the area with respect to the reference position to provide three or more levels of strength of the transmitted signal at the object during each scan to provide information at the object indicative of an alignment between the first transmitted signal and the object;

B. detecting at the object the levels of signal strength of the first transmitted signal received at the object to obtain the alignment information provided in the first transmitted signal of step A;

C. generating from the object a return signal which includes information indicative of the alignment information received at the object from which the alignment of the first transmitted signal and the object can be determined and transmitting the return signal;

D. receiving the return signal;

E. obtaining from the return signal received in step D the information indicative of alignment in step C;

F. automatically determining the angular displacement of the object with respect to the reference position from the information obtained in step E; and

G. controlling the camera control system in response to the angular displacement determined in step F.

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

H. placing a movable lens between the infrared energy source and the object;

I. transmitting the first transmitted signal through the lens; and

J. moving the lens with respect to the infrared energy source to vary the position of a predetermined level of the signal strength through the area.

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

K. detecting the position of the lens.

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

H. scanning the are substantially in the horizontal plane.

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

H. scanning the area substantially in the vertical plane.

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

H. providing an output control signal indicative of the angular displacement determined.

7. A method of tracking a movable object by calculating the displacement of the object with respect to a reference position in a camera control system comprising the steps of:

A. scanning an area containing the object with a transmitted signal from a Continuous infrared energy source by varying the position of the transmitted signal through the area during successive time intervals in a manner to provide three or more levels of the signal strength of the transmitted signal during each scan;

B. detecting at the object the levels of the transmitted signal and the object signal strength of the transmitted signal received at the object to obtain the information provided in the transmitted signal of step A;

C. generating from the object a return signal which includes information indicative of the alignment of the object relative to the reference position in response to detecting the signal in step B and transmitting the return signal;

D. receiving the signal transmitted in step C and obtaining therefrom the information indicative of an alignment of the object relative to the reference position;

E. repetitively computing the angular displacement of the object with respect to the reference position;

F. determining the direction of movement of the object by comparing the angular displacements of the object; and

G. controlling the camera control system in response to the determination of direction made in step F.

8. The method of claim 7 wherein step F includes the steps of:

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

I. 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.

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

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

10. The method of claim 7 wherein step A includes the steps of:

H. placing a movable lens between the infrared energy source and the object;

I. transmitting the signal through the lens; and

J. repetitively moving the lens with respect to the infrared energy source for varying the position of a predetermined level of the signal strength 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:

K. detecting the position of the lens during each time interval.

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

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

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

13. The method of claim 12 further including the step of:

M. selectively modifying the first output signal 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.

14. In a system for determining the location of a movable object relative to a reference position, first transmitter means disposed at the reference position for generating an infrared first energy signal, continuous scanning means for moving said first energy signal through an area in which said object is located for locating said object to provide three or more levels of the strength of said first energy signal at said object to provide information at said object indicative of an alignment between said first energy signal and said object, peak detection .sensing means for receiving said first energy signal and the three or more levels of signal strength at the object of said first energy signal and providing a first output signal indicative of the relative strength of said first energy signal that is sensed by said peak detection sensing means, second transmitter means at said object and responsive to said first output signal for generating a second non-interfering energy signal when said object is irradiated by said first energy signal and the received signal strength of said first energy signal at said object is indicative of an alignment by said peak detection sensing means, receiver means responsive to said second energy signal for providing a second output signal including said information in said second energy signal, and means responsive to said second output signal for determining the angle of said first energy signal in the area scanned by said first energy signal in response to said information in said second output signal thereby establishing the angular location of the object.

15. The system as defined in claim 14 wherein said first energy signal is transmitted as a beam.

16. A method for determining the actual angular location of a movable object relative to a reference position to control the field of view of a camera comprising the steps of:

A. generating and transmitting a first electromagnetic energy signal from the reference position;

B. moving the first energy signal from the reference position through an area in which the movable object is located;

C. generating and transmitting a second energy signal from the location of the movable object in response to irradiation of the movable object by the first energy signal from the reference position;

D. receiving the second energy signal and determining the actual angular location of the first energy signal in the area through which the first energy signal is moved in step B in response to the second energy signal from the location of the movable object thereby establishing the actual angular location of the movable object; and

E. controlling the field of view of a camera with respect to the established actual angular location of the movable object.

17. The method of claim 16 wherein step A includes transmitting of the first energy signal from the reference position in the form of a beam having a predefined shape.

18. The method of claim 16 wherein step A includes transmitting of the first energy signal from the reference position in the form of infrared.

19. A system for positioning and operating a camera mounted on a tracking unit that is movable by a controller that includes means for scanning an area with an electromagnetic signal for controlling the field of view of a camera comprising a movable object, a remote control unit, a radio frequency transmitter means located at said remote control unit, said transmitter means for transmitting a radio frequency signal from said remote control unit to said controller in response to irradiation of said movable object with said electromagnetic signal , and a radio frequency receiver means at said controller for receiving said radio frequency signal and providing control output signals for moving said tracking unit in response to said radio frequency signal to control the field of view of a camera.

20. A method of determining the displacement of one object with respect to a reference position comprising the steps of:

A. scanning an area containing the object with a transmitted signal from a radiant energy source by varying the position of the signal through the area with respect to the reference position to provide three or more levels of strength of the transmitted signal at the object during each scan of the transmitted signal for providing information at the object with respect to an alignment between the transmitted signal and the object;

B. sensing at the object the relative signal strength of the three or more levels of strength of the transmitted signal during each scan received at the object to obtain the alignment information provided in step A; and

C. determining a location during each scan with respect to the reference position where the alignment in step B occurs.

21. A method of calculating the angular displacement of one movable object with respect to a reference position comprising the steps of:

A. scanning an area containing the object with an energy signal by varying the position of the signal through the area to provide three or more levels of the strength of the transmitted signal at the movable object during each scan to provide information at the object of an alignment between the transmitted signal and the movable object;

B. sensing at the movable object the three or more levels of signal strength of the transmitted signal received at the movable object and determining an alignment;

C. generating an alignment signal from the movable object indicative of an alignment of the transmitted signal and the movable object and transmitting the alignment signal; and

D. receiving the alignment signal and computing the actual angular displacement of the movable object with respect to the reference position.

22. A method of calculating the actual angular displacement of a movable object with respect to a reference position comprising the steps of:

A. scanning an area containing the movable object with a transmitted signal from a reference location from an electromagnetic energy source by varying the position of the transmitted signal through the area to provide three or more levels of strength of the transmitted signal at the object during each scan to provide information at the object of a known level of signal strength indicative of an alignment between the transmitted signal and the object;

B. sensing at the movable object the three or more levels of signal strength of the transmitted signal received at the movable object and determining an occurrence of a known level of signal strength;

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

D. receiving the alignment signal and continuously computing the actual angular displacement of the movable object with respect to the reference position.

23. A method of tracking a movable object by calculating the displacement of the movable object with respect to a reference position in each of two planes comprising the steps of:

A. scanning an-area in two planes containing the movable object with two transmitted signals from an electromagnetic energy source by varying the position of the transmitted signals through the area in each of two planes to provide three or more levels of the strength of each transmitted signal at the object during each scan to provide information at the object of an alignment between each transmitted signal and the object;

B. sensing at the movable object the three or more levels of signal strength of each of transmitted signals received at the object;

C. generating an alignment signal from the movable object indicative of the alignment of the movable object relative to the reference position when the known level of the signal strength of each of transmitted signal was received at the movable object;

D. receiving the alignment signal from step C and automatically computing the actual angular displacement of the movable object with respect to the reference position in each of the two planes; and

E. automatically computing the direction of movement of the object in each of the two planes by comparing the actual angular displacements of the movable object respectively in each of the two planes.