KR101305405B1 - Method for Localizing Intelligent Mobile Robot by using a lateral landmark - Google Patents

Abstract

The present invention provides an intelligent mobile robot position recognition device capable of recognizing a landmark on the side and a method using the same. To this end, an image acquisition unit for acquiring an image, an image processing unit for processing the acquired image, a map generation unit for generating a map using the result of the image processing, and an image processing result and the generated map A method for recognizing a position of an intelligent mobile robot having a position recognition unit for determining a position, the method comprising: separating an image of a side and an image of a ceiling from an acquired image; Planarizing an image of the separated side; Checking whether there is a landmark in the flattened side image; Checking whether there is a landmark in the image of the separated ceiling; Removing noise of the image which has been checked for a landmark; Extracting feature points of a landmark from the image; Performing a binarization algorithm using information on extracted minutiae; Comparing the binarization information with the registered landmarks and matching the registered landmarks; And it provides a position recognition method of the intelligent mobile robot comprising the step of performing a position correction operation using a Kalman filter.

Description

Method for Localizing Intelligent Mobile Robot by using a lateral landmark}

The present invention relates to a position recognition device, and more particularly to a position recognition method of an intelligent mobile robot located on the side of the landmark.

In order for the mobile robot to move in the room, it is necessary to identify the position of the mobile robot in the indoor space. Typical techniques commonly used for locating a mobile robot include a camera using method, an ultrasonic active beacon method, and a laser scanner. Recently, there have been a lot of researches on the location recognition method using the camera because the method using ultrasonic active beacon and the method using laser scanner have to use expensive equipment.

The SLAM (Simultaneous Localization And Mapping) algorithm is used as a method of recognizing the position of the user using the acquired image and the map configuration using the camera. The slam algorithm is an algorithm that can estimate the position of the robot and the map of the surrounding environment by constructing a map of the surrounding environment at a certain position and repeating the process of finding the position of the robot again based on the configured map. The SLAM method using ceiling images generates a ceiling map using ceiling natural landmarks and recognizes its position. However, it is often difficult to estimate the position when the robot is moved to an arbitrary position with a large error.

In order to move freely in a certain space, the autonomous mobile robot should recognize the current magnetic position accurately and move from the current position to the target position without error. For this purpose, a predetermined landmark is used as a position information providing means for allowing the mobile robot to recognize the current position of the robot. As a location recognition method using a landmark, a method of capturing a landmark installed on a ceiling with a camera of a mobile robot and obtaining location information that can grasp the current location of the user with the recognized landmark is common. However, if the height of the ceiling is very high, there may be a case where the distance between the position recognition device and the ceiling is long and not recognized properly. If the location recognition device does not correctly grasp the landmark, the mobile robot equipped with the location detection device cannot perform the intended function properly.

The present invention provides a method for location recognition of an intelligent mobile robot capable of recognizing a landmark on the side.

The present invention provides an image acquisition unit for acquiring an image, an image processing unit for processing the acquired image, a map generation unit for generating a map using the result of the image processing, and an image processing result and the generated map. A method for recognizing a position of an intelligent mobile robot having a position recognition unit for determining a position, the method comprising: separating an image of a side and an image of a ceiling from an acquired image; Planarizing an image of the separated side; Checking whether there is a landmark in the flattened side image; Checking whether there is a landmark in the image of the separated ceiling; Removing noise of the image which has been checked for a landmark; Extracting feature points of a landmark from the image; Performing a binarization algorithm using information on extracted minutiae; Comparing the binarization information with the registered landmarks and matching the registered landmarks; And it provides a position recognition method of the intelligent mobile robot comprising the step of performing a position correction operation using a Kalman filter.

The present invention can recognize the location by recognizing not only the landmark of the ceiling but also the landmark located on the side. The location recognition device according to the present invention can stably recognize the location because the landmark on the side is used even when the ceiling is high or there is no landmark in the short region of the location recognition device. In addition, the landmark on the side may attach an artificial landmark, or may use a natural landmark.

1 is a block diagram of a position recognition device of an intelligent mobile robot according to an embodiment of the present invention.
2 is a diagram showing a method of recognizing the position of a mobile robot using a natural landmark and an artificial landmark in a room.
3 is a diagram illustrating an embodiment of an artificial landmark used by the position recognition apparatus of the present invention.
4 is a flowchart illustrating a process of recognizing a location by acquiring an image of a natural landmark and an artificial landmark by the position recognition device of the present invention;
Description of the Related Art
21: Natural landmark 22: Position recognition device
30: Artificial landmarks 30a to 30f: Artificial landmarks
31: Angle information mark 32: Code information mark

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in order to facilitate a person skilled in the art to easily carry out the technical idea of the present invention. do.

In order to control the robot moving in the indoor space, the function of recognizing the position of the robot in the indoor space is important every week. Generally, there are two ways to calculate the self position using camera.

First, as a method of using artificial landmarks, by installing a landmark having a specific meaning on the ceiling or wall surface and shooting it with a camera and extracting the landmark from the image, the mobile robot matches the coordinate system of the mobile robot with the coordinate system of the mobile robot. There was a way to calculate the magnetic position. Secondly, as a method of using natural landmarks, after photographing the ceiling with a camera, it extracts the linear components and edge information of the structure installed on the ceiling such as lighting fixtures and the interface between the ceiling and the wall from the image, and then uses the magnetic position of the robot. There is a way to calculate. However, in case of using artificial landmarks, there is a problem that a lot of misunderstanding occurs due to the influence of illumination and distortion of color information by sunlight. In addition, even when a natural landmark is used, there is a problem in that it is very influenced by the brightness of the ambient light source and is very difficult to use in the absence of illumination.

In general, the landmark is to use the ceiling. Artificial landmarks will also be attached to the ceiling. However, when the ceiling is very high, the distance between the location recognition device and the landmark becomes long, which makes it difficult to accurately recognize the location. In order to solve this problem, the present invention uses both a natural landmark and an artificial landmark, and provides an intelligent mobile robot position recognition apparatus that can use the landmark on the side.

Referring to FIG. 1, the position recognition apparatus according to the present embodiment includes an image acquisition unit 11 for acquiring an image, an image processing unit 12 for processing the acquired image, and a map using the result of image processing. The map generation unit 13 includes a position recognition unit 14 that determines the position of the robot using the image processing result and the generated map.

The image acquisition unit 11 captures an external image and converts it into a digital signal. The image acquisition unit 11 may include a CCD (Charge Coupled Device) module or a CMOS (Complementary Metal Oxide Semiconductor) module. The image acquiring unit 11 acquires an upright image perpendicular to the plane on which the mobile robot travels. The image acquiring unit 11 acquires an external image using visible light and converts the image into a digital signal.

The image processing unit 12 can apply the image processing algorithm to the acquired upper image to create data necessary for map generation. In addition, the image processing unit 12 can recognize the natural landmark 21, and can additionally recognize the artificial landmark 30. FIG. The image processing unit 12 extracts feature points through various image processing algorithms using the input image.

The map generating unit 13 can generate a map by using the data generated by the image processing unit 12. The map generating unit 13 can generate an accurate map using not only natural landmarks but also artificial landmarks. Also, the map generating unit 13 can search for the data registered in the image processing unit 12 by using the feature point matching algorithm. Also, the map generating unit 13 can search the image information matching with the minutia extracted from the new image from the image map, and add the new image map to the new image map if the image information does not exist in the image map.

The position recognition unit 14 may calculate the position of the robot using the data generated by the image processor 12 and the map data generated by the map generator 13. The position recognition unit 14 may search image information matching the feature points extracted from the acquired image from the image map and calculate the position of the mobile robot using the searched results. The position recognition unit 14 may increase the accuracy of position recognition by additionally using an artificial landmark. In addition, the position recognition unit 14 recognizes both the natural landmark 21 and the artificial landmark 30 to recognize the position. Therefore, the position recognition device according to the present embodiment can recognize the position more accurately and quickly.

2 is a diagram illustrating a method of recognizing the position of a mobile robot using a natural landmark and an artificial landmark in a room.

2, an image including the natural landmark 21 and the artificial landmark 30 is captured through the sensor provided with the mobile robot 22, and the natural landmark 21 and the natural landmark 21 are captured through the captured image, The artificial landmark 30 is discriminated.

3 is a diagram illustrating an embodiment of an artificial landmark used by the position recognition apparatus of the present invention.

Fig. 3 illustrates a preferred embodiment of the artificial landmark 30 applied to the present invention. 3, an angle information mark 31 for obtaining a rotation angle and a code information mark 32 for distinguishing a code are arranged in an artificial landmark, One code. The artificial landmark 30 in the form of a code is installed on the ceiling of the room.

The mobile robot 22 recognizes the artificial landmark 30 using the installed image acquisition unit 11 and generates an image for position recognition. The artificial landmark 30 having the code shape can analyze the artificial landmark 30 while the mobile robot 22 moves and can detect the distance and the angle of rotation based on the artificial landmark 30 .

The artificial landmark 30 in the form of a code can not only use one artificial landmark but also can recognize a position in one coordinate system in a wide area using a plurality of artificial landmarks 30a to 30f and the like . In addition, one or two artificial landmarks 30 in the form of a cord can be used in the middle in a large area.

The position recognition device of the mobile robot according to the present embodiment recognizes both the natural landmark 21 and the artificial landmark 30, and corrects the position by using the landmarks of the side image and the ceiling image. It can improve performance.

FIG. 4 is a flowchart illustrating a process of recognizing a location by acquiring an image of a natural landmark and an artificial landmark according to an embodiment of the present invention.

Referring to FIG. 4, the operation of the position recognition apparatus according to an exemplary embodiment of the present invention will first flatten the obtained image through an algorithm of a wide-angle curved image.

The biggest feature of the position recognition device according to the present embodiment is that the landmark on the side can be recognized. Unlike the landmarks on the ceiling, the image of the landmark on the side is in an added state to the acquired image. Therefore, only by correcting the angle, it is possible to perform the position recognition operation such as processing the landmark on the ceiling.

Next, the image related to the ceiling and the image related to the side are separated from the acquired image. Next, the independent side image is flattened. Then check whether there is a natural landmark in the flattened side image. Also, check whether there is a natural landmark or an artificial landmark in the independent ceiling image. Then, an image preprocessing process for eliminating a job image of an image confirmed to have a natural landmark and an artificial landmark is performed. This process is the process of removing the noise in the image. The noise removal process can be selected from various processes and is not fixed to any one process.

Then, if it is confirmed that the input image has a natural landmark, the feature point of the natural landmark is extracted. If it is confirmed that there is an artificial landmark on the input image, the feature point of the artificial landmark is extracted. Next, it is judged whether or not the image is photographed in the state that there is an external light source (sunlight, illumination) on the input image.

If there is no external light source, apply a general binarization algorithm. If there is an external light source, apply a robust binarization algorithm to the external light source. In this case, the binarization algorithm robust to the external light source is to reduce the value of the image to be processed collectively or to pass through a certain predetermined filter so that the data can be processed more efficiently. If there is a light source, the value of the processed image value is too high to be effective in processing the image. The binarization algorithm is an algorithm that divides each pixel value constituting an image into two types (for example, black and white) by a predetermined reference value.

Subsequently, the object of the current screen is compared with the registered natural landmark and the artificial landmark and matched. Next, data noise removal and position correction using a Kalman filter are performed. In this process, a map for location recognition is created. The heading angle is then detected along a fixed line of the object. Subsequently, the operation of correcting the position using the input image is completed.

Since the mobile robot having the position recognition device according to the present embodiment described above performs and corrects the position recognition using both the natural land mark and the artificial land mark using visible light, the position recognition can be effectively recognized. In addition, since the landmark on the side can be recognized and used for position correction, position recognition can be performed more effectively.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. I will understand. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims, as well as the appended claims.

Claims (5)

An image acquisition unit for acquiring an image, an image processing unit for processing the acquired image, a map generation unit for generating a map using the result of the image processing, and an image processing result and a generated map for determining the position of the robot In the method for recognizing the position of the intelligent mobile robot having a position recognition unit,
Separating the image of the side and the image of the ceiling from the acquired image;
Planarizing an image of the separated side;
Checking whether there is a landmark in the flattened side image;
Checking whether there is a landmark in the image of the separated ceiling;
Removing noise of the image which has been checked for a landmark;
Extracting feature points of a landmark from the image;
Performing a binarization algorithm using information on extracted minutiae;
Comparing the binarization information with the registered landmarks and matching the registered landmarks; And
Performing the position correction using the Kalman filter
A position recognition method of an intelligent mobile robot including a robot;
The method of claim 1,
The step of checking if there are landmarks in the flattened side image
Intelligent mobile robot position recognition method characterized in that the check whether there is a natural landmark or an artificial landmark on the flattened side image.
The method of claim 1,
The step of checking if there is a landmark in the image of the separated ceiling
Intelligent mobile robot position recognition method, characterized in that whether there is a natural landmark or artificial landmark in the image of the separated ceiling.
The method of claim 1,
And detecting a heading angle according to the fixed straight line of the landmark.
The method of claim 1,
The step of performing the binarization algorithm using information on the extracted feature points
If no external light source was present, applying a general binarization algorithm; And
And applying a robust binarization algorithm to an external light source if an external light source is present.

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