JPH07101167B2 - Image sensor illumination method and apparatus thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention holds an image sensor such as a TV camera at the hand of a robot, and uses pattern recognition to detect the shape and position of an object or to detect the appearance of the object. Involved in the recognition system,
In particular, the present invention relates to an image sensor illumination method and apparatus suitable for performing stable and constant illumination of illumination light during pattern recognition regardless of the distance between a TV camera and an object.

[Background of the Invention]

In the conventional illumination method for robot vision, for example, “Robot Vision 1983, pp. 305 to 311, PF Hewkin and HJFuchs,“ OMS ” − Vision System ”(OMS-Vision SYSTE
As described in the document entitled "M)", a method of applying illumination light from a fixed position outside the work range of the robot to the entire work range to be recognized is used.

However, since it is difficult to apply uniform illumination to the entire target range with the above method, and the input image size is often partial in the target recognition range in robot vision, the When a part of the image within the work range is input by moving the, the brightness of each input image becomes different, and the pattern recognition accuracy is reduced.

Also, if the distance between the recognition target and the TV camera changes due to differences in the size of objects to be recognized, the brightness will change each time, causing further deterioration of recognition accuracy. Was there.

Also, even if you attach the lighting device to the hand of the robot to illuminate it,
However, there is a drawback in that the appropriate illumination condition is satisfied only within a certain defined small distance between the recognition target and the TV camera.

[Object of the Invention]

The object of the present invention is to eliminate the above-mentioned drawbacks, and in a simple method, always apply a constant illumination light regardless of the distance between the recognition target and the TV camera, without deteriorating the recognition accuracy of the robot visual recognition, and the pattern. An object of the present invention is to provide an illumination method of an image sensor and a device thereof that enable recognition processing.

[Outline of Invention]

The present invention, in order to achieve the above object, in a method of recognizing a pattern by converting an object requiring illumination light into an electric signal with a photoelectric sensor, detecting distance data between the photoelectric sensor and the object, and The illumination light quantity and the illumination direction of the illumination light are controlled based on the distance data, the illumination light is illuminated on the same part as the input field of view of the TV camera, and the object is illuminated under a constant and optimal illumination condition. Is what
As a preferred embodiment, in a pattern recognition device for recognizing a pattern by converting an object requiring illumination light into an electric signal by a photoelectric sensor, an illumination mechanism for illuminating the object with illumination light, the photoelectric sensor and the object And a detection mechanism for detecting distance data with the detection mechanism, and controls the illumination direction of the illumination light from the illumination mechanism based on the detection result of the distance data by the detection mechanism so as to be in the same part as the input field of view of the photoelectric sensor, and A control mechanism for controlling the brightness of the illumination light from the illumination mechanism based on the detection result of the distance data is provided.

Example of Invention

Hereinafter, FIGS. 1 to 3 showing an embodiment of the present invention will be described. FIG. 1 is a perspective view showing a case where an illumination device for an image sensor according to the present invention is attached to a robot, and FIG.
FIG. 3 is an enlarged explanatory view showing an illumination device of the image sensor shown in FIG.
The figure is an enlarged explanatory view showing the illumination light amount control device and the illumination angle control device shown in FIG.

In FIG. 1, reference numeral 1 is a robot, and the hand 3 is in the direction of arrow A (up and down direction) in response to a command from the robot controller 2.
It is formed to be movable. A base 4 is fixedly supported by the hand 3 and has a lighting device 5, a lighting device driving device 6 and a TV camera 7 mounted thereon. The illuminating device 5 is rotated in the direction of the arrow B by the illuminating device driving device 6, and its optical axis
It is formed so that 6a can be adjusted, and the illumination light amount can be adjusted based on a command from an illumination light amount control device 10 described later. The illumination device drive device 6 is formed of, for example, a motor and is rotated by a command from an illumination angle control device 14 described later to rotate the illumination device 5 by a predetermined angle. 8a, 8b, 8c are the parts to be recognized,
The traveling device 9 travels in the direction of arrow C and stops at a predetermined position. Reference numeral 10 denotes an illumination light quantity control device, which comprises a data latch 11, a data conversion circuit 12, and a variable power supply 13. The data latch 11 inputs the command value 2a corresponding to the distance l from the TV camera 7 to each of the components 8a, 8b, 8c and the distance fl between the TV camera 7 and the lighting device 5 from the robot controller 2 in advance and stores it. At the same time, the first command value 2a and the command value changed with respect to the command value 2a are sent to the data conversion circuit 12. The data conversion circuit 12 previously detects the distance fl between the TV camera 7 and the lighting device 5, the distance l between the TV camera 7 and the components 8a, 8b, 8c, and the illumination light from the lighting device 5 to the components 8a, 8b, 8c. The relation with the light quantity (brightness) is calculated and stored as a data table, and the data corresponding to the light quantity of the illumination light is sent to the variable power source 13 based on the command value from the data latch 11. The variable power source 13 controls the current or voltage based on the data from the data conversion circuit 12 and sends the current or voltage corresponding to a predetermined light amount to the lighting device 5. Therefore, the illumination light amount control device 10 determines, based on the command value corresponding to the distance 1 between the TV camera 7 and each component 8a, 8b, 8c from the robot control device 2 and the distance fl between the TV camera 7 and the illumination device 5, It is possible to illuminate each component 8a, 8b, 8c from the illumination device 5 with the optimal amount of illumination light corresponding to this command value. An illumination angle control device 14 is formed of a data latch 15, a data conversion circuit 16 and a driver 17. The data latch 15 is similar to the data latch 11 of the illumination light amount control device 10 in advance from the robot control device 2 to the TV.
The distance l from the camera 7 to each of the components 8a, 8b, 8c and the command value 2a corresponding to the distance fl between the TV camera 7 and the lighting device 5 are input and stored, and the command value 2a changes with the time of storage. When the command value is input, it is sent to the data conversion circuit 16. The data conversion circuit 16 has the distance fl between the TV camera 7 and the lighting device 5, the TV camera 7 and the parts 8 beforehand.
The relationship between the distance l between a, 8b, 8c and the angle α for illuminating the components 8a, 8b, 8c with the illumination light from the illumination device 5 is calculated by the following equation (1). This is stored as a data table, and data corresponding to the illumination angle α of the illumination device 5 is sent to the driver 17 based on a command from the data latch 15. The driver 17 sends a driving signal to the lighting device driving device 6 based on the data from the data conversion circuit 16. Therefore, the illumination angle control device 14 outputs this command based on the command value corresponding to the distance 1 between the TV camera 7 and each component 8a, 8b, 8c from the robot control device 2 and the distance fl between the TV camera 7 and the lighting device 5. It is possible to irradiate each of the components 8a, 8b, 8c from the illumination device 5 with the illumination angle α corresponding to the value.

Since the illumination device of the image sensor according to the present invention is configured as described above, when the TV camera 7 is attached to the hand 3 of the robot 1 and the pattern recognition of each of the components 8a, 8b, 8c is performed, each of the recognition targets is recognized. Even if the distance l between the components 8a, 8b, 8c and the TV camera 7 is changed, the illumination light can always be illuminated at the same component position as the input field of view of the TV camera 7, and the brightness is always constant and optimum. The components 8a, 8b, 8c can then be illuminated.

Therefore, flexible recognition processing can be performed without lowering the pattern recognition accuracy.

In the above embodiment, the case where the command value from the robot control device 2 is used as a basis has been described, but the present invention is not limited to this. For example, a distance sensor is installed at the hand 3 of the robot 1 and is always provided. It is also possible to easily control the illumination angle α and the illumination light amount of the illumination device 5 online.

〔The invention's effect〕

According to the present invention, a sensor such as a TV camera is moved so that the illumination light in a pattern recognition application system such that the distance to an object is changed can be always applied with an optimum illumination light. Not only is the accuracy improved, but even for large objects, even if the field of view of the recognition unit is a part of the object, uniform illumination is not required overall, so the scale of the entire device system is large. Can be miniaturized, which can significantly reduce the cost.

[Brief description of drawings]

FIG. 1 is a perspective view of an image sensor illumination device according to an embodiment of the present invention when it is attached to a robot, FIG. 2 is an enlarged explanatory view of the image sensor illumination device shown in FIG. 1, and FIG. FIG. 3 is an enlarged explanatory diagram of an illumination light amount control device and an illumination angle control device shown in FIG. 2. 1 ... Robot, 2 ... Robot control device, 3 ... Minions, 4 ... Base, 5 ... Lighting device, 6 ... Lighting device drive device, 7 ... TV camera, 8a, 8b, 8c. Parts, 9 ...
Traveling device, 10 ...... Illumination light amount control device, 14 ...... Illumination angle control device.

Claims (2)

[Claims] 1. A TV camera and a lighting device are attached to the hand of the robot, a visual field for catching an object to be recognized is set by the movement of the robot, an image obtained by the TV camera is pattern-recognized, and the robot is based on the result. In a system in which work is performed on a recognition target object with a hand, the robot controller detects the distance between the TV camera and the recognition target object based on the operation result, and the illumination light amount control device detects the distance between the TV camera and the recognition target object. , Calculates the amount of illumination light that makes the illuminance of the recognition target constant based on the distance between the TV camera and the illumination device, and controls the current or voltage of the illumination device based on the amount of illumination, and an illumination angle control device Calculates the illumination angle of the illumination device based on the distance between the TV camera and the recognition object and the distance between the TV camera and the illumination device, and attaches to the hand of the robot based on the illumination angle. A method as an image sensor, characterized by drive control of the lighting device for a drive apparatus. 2. A TV camera and a lighting device are attached to the hand of the robot, a visual field for catching a recognition object is set by the movement of the robot, an image obtained by the TV camera is pattern-recognized, and the robot is based on the result. In a system for working on an object to be recognized with a hand, the robot controller is provided with means for detecting the distance between the TV camera and the object to be recognized from the operation result, and the distance between the TV camera and the object to be recognized and the TV camera. Based on the distance between the illumination device and the lighting device, calculates the light amount of the illumination light that makes the illuminance of the recognition target constant, and an illumination light amount control device that controls the current or voltage of the illumination device based on the light amount, and the TV. The lighting angle of the lighting device is calculated based on the distance between the camera and the recognition object and the distance between the TV camera and the lighting device, and the lighting attached to the hand of the robot based on the lighting angle. Lighting device of the image sensor is characterized by providing an illumination angle control device that drives and controls the 置用 drive.