AUTOMATIC-TRACKING CAMERA APPARATUS

• US 20080055413A1
• Filed: 08/31/2007
• Published: 03/06/2008
• Est. Priority Date: 09/01/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hayashi, Tadashi
• Granted Patent: US 8,174,580 B2
• Time in Patent Office: Days
• US Class Current: 348/169
• CPC Class Codes: G01C 11/02 Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures
• CPC Class Codes: H04N 13/221 using the relative movement between cameras and objects
• CPC Class Codes: H04N 23/61 based on recognised objects
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body
• CPC Class Codes: H04N 23/66 Remote control of cameras or camera parts, e.g. by remote control devices
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/682 Vibration or motion blur correction
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• 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

An automatic-tracking camera apparatus which is capable of realizing continuous and smooth driving and obtaining an image with little position variation of a tracking target from a target position within the image and with little blur. The position of a camera body is changed by a gimbal device. The speed of a tracking target object at the next-after-next start timing of image acquisition by the camera body is predicted. The gimbal device is controlled so that the camera body reaches the position indicated by a position instruction value generated for the next-after-next start timing of image acquisition by the camera body, at the next-after-next start timing, and the speed of the camera body at the next-after-next start timing of image acquisition by the camera body corresponds to the speed predicted for the next-after-next timing of image acquisition.

Claims

1. An automatic-tracking camera apparatus comprising:

an image pickup unit adapted to change the position thereof and acquire an image in a constant cycle;

an actuator adapted to change the position of said image pickup unit;

a position grasping unit adapted to grasp the position of said image pickup unit;

a position instruction value generation unit adapted to generate a position instruction value for instructing a target position of said image pickup unit at the next-after-next start timing of image acquisition by said image pickup unit, on the basis of the image acquired by said image pickup unit and the position of said image pickup unit grasped by said position grasping unit, in synchronization with the cycle of image acquisition by said image pickup unit;

a speed prediction unit adapted to predict the speed of a tracking target object at the next-after-next start timing of image acquisition by said image pickup unit; and

a control unit adapted to control said actuator so that said image pickup unit reaches the position indicated by the position instruction value generated for the next-after-next start timing of image acquisition by said image pickup unit, at the next-after-next start timing, and the speed of said image pickup unit at the next-after-next start timing of image acquisition by said image pickup unit corresponds to the speed predicted by said speed prediction unit for the next-after-next timing of image acquisition.

2. An automatic-tracking camera apparatus according to claim 1, wherein said control unit adapted to control said actuator so that said image pickup unit is displaced at a constant acceleration during the period from the start timing of image acquisition by said image pickup unit to the next start timing of image acquisition.

3. An automatic-tracking camera apparatus according to claim 1, wherein said control unit adapted to control said actuator so that change in the acceleration of said image pickup unit during the period of image acquisition by said image pickup unit is the minimum.

4. An automatic-tracking camera apparatus according to claim 3, wherein said control unit adapted to control said actuator so that the acceleration of said image pickup unit gradually increases during the period from generation of the position instruction value by said position instruction value generation unit to the start timing of image acquisition by said image pickup unit.

5. An automatic-tracking camera apparatus comprising:

an image pickup unit adapted to change the position thereof and acquire an image in a constant cycle;

an actuator adapted to change the position of said image pickup unit;

a position grasping unit adapted to grasp the position of said image pickup unit;

a signal generation unit adapted to generate a position instruction value for instructing the target position of said image pickup unit and a feedforward signal, on the basis of an image acquired by said image pickup unit and the position of said image pickup unit grasped by said position grasping unit, in the same cycle as the cycle of image acquisition by said image pickup unit; and

a control unit adapted to control said actuator in a cycle shorter than the cycle of image acquisition by said image pickup unit, on the basis of the position instruction value and the feedforward signal generated by said signal generation unit.

6. An automatic-tracking camera apparatus according to claim 5, wherein said control unit adapted to control the maximum driving force of said actuator on the basis of the feedforward signal.

7. An automatic-tracking camera apparatus according to claim 5, wherein said control unit adapted to output a signal for controlling said actuator by performing at least proportional operation or proportional differential operation of the deviation between the position instruction value and the position grasped by the position grasping unit, and change at least one of the proportional gain of the proportional operation and the differential gain of the proportional differential operation on the basis of the feedforward signal.

8. An automatic-tracking camera apparatus according to claim 5, wherein said signal generation unit adapted to perform at least proportional operation of the deviation between the target position instructed by the position instruction value and the position at the time of generation of the instruction value to generate the feedforward signal.

9. An automatic-tracking camera apparatus according to claim 5, wherein the feedforward signal is a value learned on the basis of the deviation between the time when said image pickup unit reaches the target position and the time when the target position is updated.