System for and method of recognizing and tracking target mark
First Claim
1. A target mark tracking system for tracking a target mark with a video camera, comprising:
- a target mark disposed on an object and composed of a black circle and a white triangle centered within said black circle and three-dimensionally shifted from the black circle;
a video camera for imaging said target mark;
a moving mechanism supporting said video camera and movable in directions with six degrees of freedom;
image processing means for processing image data of said target mark from a projected position based on histogram information of said target mark which is produced by said image processing means; and
moving mechanism control means for controlling movement of said moving mechanism depending on said shift to enable said video camera to track said target mark;
wherein said image processing means processes the image data of said target mark in an image coordinate system to recognize the target mark, store the image data, convert the image data to binary image data, and generate X- and Y-projected histograms.
1 Assignment
0 Petitions
Accused Products
Abstract
A system for and a method of recognizing and tracking a target mark with a video camera is disclosed. The system includes a target mark (10) disposed on an object (1) and composed of a black circle and a white triangle mounted centrally on the black circle and three-dimensionally shifted from the black circle, a video camera (20) for imaging the target mark (10), a robot (30) supporting the video camera (20) and movable in directions with six degrees of freedom, an image processor (40) for processing image data of the target mark which is produced by the video camera (20), a shift calculating unit (50) for detecting a shift of the target mark (10) from projected histogram information of the target mark (10) which is produced by the image processor (40), and a robot controller (60) for controlling movement of the robot depending on the shift to enable the video camera (20) to track the target mark (10). The system is capable of tracking the target mark ( 20) attached to the object (1) on a real-time basis. Mark recognizing apparatus capable of accurately recognizing target marks of other shapes is also disclosed.
157 Citations
14 Claims
-
1. A target mark tracking system for tracking a target mark with a video camera, comprising:
-
a target mark disposed on an object and composed of a black circle and a white triangle centered within said black circle and three-dimensionally shifted from the black circle; a video camera for imaging said target mark; a moving mechanism supporting said video camera and movable in directions with six degrees of freedom; image processing means for processing image data of said target mark from a projected position based on histogram information of said target mark which is produced by said image processing means; and moving mechanism control means for controlling movement of said moving mechanism depending on said shift to enable said video camera to track said target mark; wherein said image processing means processes the image data of said target mark in an image coordinate system to recognize the target mark, store the image data, convert the image data to binary image data, and generate X- and Y-projected histograms. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A visual target mark tracking control system for imaging a target mark with a video camera and processing image data of the target mark produced by the video camera to hold said video camera in a predetermined positional relationship to the target mark at all times, comprising:
-
image change detecting means for detecting a change from a target position and attitude for said target mark in an image of said target mark produced by said video camera; actual change detecting means for detecting a relative actual change from the predetermined positional relationship between said video camera and said target mark; and relating means for experimentally shifting the predetermined positional relationship between said video camera and said target mark, and relating values which are detected by said image change detecting means and said actual change detecting means when the predetermined positional relationship is experimentally shifted, to each other. - View Dependent Claims (9, 10)
-
-
11. A visual target mark tracking control system for imaging a target mark with a video camera and processing image data of the target mark produced by the video camera to hold said video camera in a predetermined positional relationship to the target mark at all times, comprising:
-
image change detecting means for detecting a change from a target position and attitude for said target mark in an image of said target mark produced by said video camera; actual change detecting means for detecting a relative actual change from the predetermined positional relationship between said video camera and said target mark; deriving means for experimentally shifting the predetermined positional relationship between said video camera and said target mark, relating values which are detected by said image change detecting means and said actual change detecting means when the predetermined positional relationship is experimentally shifted, to each other, and deriving a relative actual change from the predetermined positional relationship between said video camera and said target mark from the values detected by said image change detecting means; and control means for multiplying said actual change derived by said deriving means by a proportional gain, calculating a speed command in a coordinate system which is shifted by the distance between said video camera and said target mark with respect to a rotational component, and using the calculated speed command as a speed command for positionally controlling said video camera.
-
-
12. A visual target mark tracking control system for imaging a target mark with a video camera and processing image data of the target mark produced by the video camera to hold said video camera in a predetermined positional relationship to the target mark at all times, comprising:
-
image change detecting means for detecting a change from a target position and attitude for said target mark in an image of said target mark produced by said video camera; actual change detecting means for detecting a relative actual change from the predetermined positional relationship between said video camera and said target mark; deriving means for experimentally shifting the predetermined positional relationship between said video camera and said target mark, relating values which are detected by said image change detecting means and said actual change detecting means when the predetermined positional relationship is experimentally shifted, to each other, and deriving a relative actual change from the predetermined positional relationship between said video camera and said target mark from the values detected by said image change detecting means; and control means for determining a shift of the attitude of said video camera in a coordinate system fixed to said video camera from the actual change derived by said deriving means, and multiplying the determined shift by a constant gain to produce a speed command for positionally controlling said video camera.
-
-
13. A method of detecting a target mark comprising the steps of:
-
converting an original image to binary images; grouping the binary images into images with joined pixels; determining X- and Y-projected histograms of the grouped images; counting extreme values of the X- and Y-projected histograms of the grouped images; and comparing the counted extreme values with predetermined extreme values of X- and Y-histograms of a target mark to determine whether the grouped images represent the target mark. - View Dependent Claims (14)
-
Specification