KR101542498B1 - Robot cleaner and method for detecting position thereof - Google Patents

Abstract

A robot cleaner and a method for detecting its position are disclosed. According to the present invention, various sensors for detecting a change in position and attitude are provided. The traveling condition of the robot cleaner is determined according to the sensor information, and a suitable sensor combination is selected according to the determined traveling condition or sensor fusion is performed considering uncertainty The position of the robot cleaner is detected robustly, and an environment map is generated.

Robot cleaner, position, camera, OFS

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a robot cleaner,

The present invention relates to a robot cleaner capable of detecting a precise position such as a slip or a collision, and a position detecting method therefor.

In general, robots have been developed for industrial use and have been part of factory automation. In recent years, medical robots, aerospace robots, and the like have been developed, and household robots that can be used in ordinary homes are being developed.

A representative example of the domestic robot is a robot cleaner, which is a type of household appliance that sucks and cleanes dust or foreign matter around the robot while traveling in a certain area by itself. Such a robot cleaner is generally equipped with a rechargeable battery and has an obstacle sensor capable of avoiding obstacles during traveling, so that it can run and clean by itself.

In order to clean the entire area while the robot cleaner is traveling on its own, it is necessary to be able to determine a cleaning area such as a cleaned area and an area to be cleaned. In order to grasp the cleaning area, .

The robot cleaner according to the related art uses only sensors that can estimate a change in relative robot operation such as an encoder, a gyroscope, or the like that detects the rotation of the wheel for position recognition, The position of the robot is estimated.

However, the robot cleaner according to the related art does not have sensor information for determining a slip situation, and lacks complementary sensor information for movement, resulting in a large position error even when the camera is used.

The present invention provides a robot cleaner robust against slippage or collision by selecting various sensor combinations according to driving conditions or performing sensor fusion considering uncertainty by providing various sensors for detecting changes in position and attitude, .

According to an aspect of the present invention, there is provided a robot cleaner including a first detection unit for detecting a position based on upper image information and outputting first position information, a position detection unit for detecting a position based on downward image information, A third detection unit for detecting a position based on the rotation of the wheel motor for driving the wheels and outputting the third position information; And a control unit for determining the current position of the robot cleaner on the basis of the current position of the robot cleaner and determining the running state.

According to another aspect of the present invention, there is provided a method for detecting a position of a robot cleaner including a first detecting step of detecting a position based on upper image information and outputting first position information, A third detecting step of detecting a position based on the rotation of the wheel motor for driving the wheels and outputting the third position information; And determining a current position of the robot cleaner based on the comparison result.

According to the present invention, various sensors for detecting a change in position and attitude are provided. In accordance with the sensor information, a driving condition of the robot cleaner is determined, a suitable sensor combination is selected according to the determined driving condition, or sensor fusion is performed considering uncertainty The position of the robot cleaner can be detected robustly by slipping, collision, or the like.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a robot cleaner and a position detecting method according to the present invention will be described in detail with reference to the accompanying drawings.

1 and 6, a robot cleaner according to an exemplary embodiment of the present invention includes a first detection unit 100 for detecting a position based on upper image information and outputting first position information, A third detection unit 300 for detecting the position based on the rotation of the wheel motor for driving the wheels and outputting the third position information, And a control unit 500 for determining the current position of the robot cleaner based on two or more pieces of positional information of the positional information and determining the running state of the robot cleaner.

2, the first detection unit 100 includes a camera 110 that captures an image of the upper side and outputs upper image information, a feature extraction unit 110 that extracts feature points from the upper image information, And an image processing unit (120) for generating one position information. The first detection unit 100 includes a lens 130 coupled to the camera 110 to focus the subject, a camera control unit 140 to control the camera 110, 130) for adjusting the angle of view of the lens.

The lens 130 uses a lens having a wide angle of view so that all the areas above the predetermined position, for example, the entire area of the ceiling, can be photographed. For example, a lens having an angle of view of 160 degrees or more. The image processing unit 120 can extract feature points from an arbitrary landmark. In particular, feature points are extracted using natural markers such as fluorescent lamps and interior structures existing in an upper region including a ceiling scene.

The minutiae extraction process according to the present invention will be described with reference to FIG. The minutiae can be extracted after the image is photographed once. However, for convenience of explanation, the operation of picking up the minutiae by photographing twice during the movement will be described. 7, when the first mark C1 and the second mark N1 are compared with each other, the robot cleaner moves while the first time k and the second time k + 1) and the upper part including the ceiling scene, respectively. At this time, the first mark C1 and the second mark N1 in the upper image information photographed at the first time (k) and the second time (k + 1) are the first feature point M1 and the second feature point M2). At this time, the first mark C1 and the second mark N1 appear as a first feature point M1 (k) and a second feature point M2 (k). On the other hand, the first mark C1 and the second mark N1 at the second time (k + 1) correspond to the first feature point M1 (k + 1) and the second feature point M2 (k + 1) appear.

The image processing unit 120 generates the first feature point M1 (k), the second feature point M2 (k), which are feature points of the upper image information for the first mark C1 and the second mark N1, The first feature point M1 (k + 1) and the second feature point M2 (k + 1) are respectively matched and compared, and the movement distance between the feature points is calculated. That is, as shown in FIG. 7C, the movement distance PL1 of the first feature point is compared with the feature point of the image information photographed at the first time k and the second time k + 1, And calculates the movement distance PL2 of two minutiae. At this time, the moving distance L1 between the first mark C1 and the second mark N1 and the robot cleaner according to the movement of the robot cleaner is constant and equal to the actual moving distance of the robot cleaner. However, the movement distances PL1 and PL2 of the feature points of the photographed image information are different from each other. As the distance of the mark increases, the travel distance of the minutiae to the mark is smaller, whereas the closer the mark is to the robot cleaner, that is, the lower the wall surface than the ceiling, the greater the difference in travel distance. Accordingly, when the moving rate of the minutiae corresponding to the movement of the robot cleaner is equal to or larger than a predetermined ratio, the image processing unit 120 determines that the unnecessary minutia is present and removes it as in the second mark N1.

Since the first mark C1 of the first mark C1 and the first mark C1 of the second mark N1 are located in the ceiling scene, the image processing unit 120 may use the distance from the robot cleaner to the ceiling scene, (N1) is calculated. If the calculated height is equal to or lower than the reference height, it is determined as an unnecessary feature point and removed. When the first feature point M1 and the second feature point M2 are compared, the movement distance PL1 of the first feature point M1 and the movement distance PL2 of the second feature point M2 with respect to the respective movement distances, 2 mark, and the ratio of the actual moving distance and height of the robot cleaner. At this time, since the actual moving distance is the same and the height of the first characteristic point M1 is the ceiling height, the height of the second characteristic point M2, i.e., the second mark N1, can be calculated. Here, it is determined that the feature points located in the central part of the captured upper image information are located in the ceiling scene, and the height of the feature points is calculated based on the feature points located in the center part.

The control unit 500 may include features of the image processing unit 120 or may include the feature point extraction algorithm and simultaneously perform position detection and environment map generation using SLAM (Simultaneous Localization and Mapping) .

3, the second detection unit 200 includes an image sensor 210 for capturing downward and outputting downward image information, a light amount control unit 220 for controlling the light amount irradiated downward, And an image control unit 230 for generating second position information based on the downward image information. The second detection unit 200 may further include a distance measurement unit 240 for measuring a distance from the image sensor 210 to the floor surface. The distance measurement unit 240 may measure an infrared ray, an ultrasonic wave, And measures the distance from the time when the transmitted signal is reflected and returned.

The image sensor 210 may use a camera having the same function as the camera 110. However, unlike the camera 110, the image sensor 210 acquires downward image information by capturing a downward image, that is, . As the image sensor, it is preferable to use an optical flow sensor (OFS) for acquiring the downward image information using light.

Hereinafter, the operation of the second detection unit 200 will be described. The image sensor 210 is provided on the back side of the robot cleaner, and photographs the bottom, that is, the bottom of the robot cleaner. The image sensor 210 captures a downward image and generates downward image information of a predetermined format. The second detecting unit 200 may further include a lens (not shown) and a lens adjusting unit (not shown) for adjusting the lens. The lens may be a pan-focus lens having a short focal length and a deep depth, And the lens adjusting unit includes a predetermined motor and moving means for moving the lens adjusting unit back and forth to adjust the lens. The light amount adjusting unit 220 is disposed adjacent to the image sensor 210 and adjusts one or more light sources (not shown) to illuminate a bottom surface area photographed by the image sensor 210 do. In other words, when the robot cleaner moves on a flat floor, the image sensor 210 maintains a certain distance to the bottom surface. On the other hand, when the robot cleaner moves on the bottom surface of an uneven surface, It will move away. At this time, the light amount adjusting unit 220 operates one or more light sources corresponding to the distance measured from the distance measuring unit 240 to adjust the amount of the irradiated light. On the other hand, the image sensor 210, particularly the optical flow sensor, can detect a relative position regardless of slip. That is, by observing the underside of the robot cleaner using the optical flow sensor, it is possible to perform position correction that is robust against slippage.

The control unit 500 includes a comparison unit (not shown) for comparing two or more pieces of position information among the position information, and a map generation unit (not shown) for generating an environment map based on the comparison result, Create an environmental map based on information. That is, the control unit 500 generates an environment map using the feature points extracted from the upper image information through the first detection unit 100, and detects the environment map from the downward image information through the second detection unit 200 The position of the robot cleaner can be determined by fusing the positional information robust to the slip, and the environment map can be generated again.

Conversely, for example, in the case of an optical flow sensor other than a laser type, there is a phenomenon that the signal is interrupted when the bottom is a reflective material. At this time, if the video information of the first detection unit 100 is used, it can be clearly seen whether the signal is lost due to slip or the bottom is broken because of the reflection material.

The third detection unit 300 senses the rotation speed of the wheel motor provided in the traveling unit 620 of the robot cleaner and detects the rotation speed or the linear velocity. The rotation speed or the linear velocity is subjected to a predetermined operation such as double integration To generate third position information. As the third detection unit 300, an encoder is generally used.

The robot cleaner according to another exemplary embodiment of the present invention further includes a fourth detection unit 400 for detecting the position based on the direction information of the robot cleaner and outputting fourth position information. Other configurations are described with reference to the configuration of the robot cleaner according to the above example.

That is, the fourth detection unit 400 detects the rotation speed, that is, the angular velocity, while sensing the change in direction during movement of the robot cleaner, and generates the fourth position information from the angular velocity through a predetermined operation such as double integration. As the fourth detection unit 400, a gyroscope (angular velocity sensor) is generally used.

The first to third detection units or the first to fourth detection units may be combined or selectively applied to precisely detect the position of the robot cleaner. For example, the robot cleaner can acquire feature points and draw an environmental map through image processing using the camera 110 provided in the first detection unit 100, and can calculate the position of the robot cleaner based on the environmental map However, due to slippage and collision, the environment map becomes inaccurate due to the movement of the robot cleaner, resulting in a position detection error. This position detection error can be easily detected from the speed by using the encoder 300, the gyroscope 400 or the encoder and the gyroscope, and is detected by the material of the floor By using the image sensor 210 which is resistant to slippage. On the other hand, only the detecting unit for detecting the relative position of the encoder as the third detecting unit 300 or the relative position of the gyroscope used as the fourth detecting unit 400 can be set to a condition such as a floor having a large slip of the wheel The optical flow sensor, which is the second detection unit 200, can generate the position information irrespective of the slip.

The control unit 500 compares the position information generated from the first to third detection units or the first to fourth detection units to determine the running condition of the current robot cleaner, Or sensor fusion is performed by adjusting the uncertainty of each sensor information. Also, the control unit 500 may include a comparison unit (not shown) for comparing two or more pieces of position information among the position information, and a map generation unit (not shown) for generating an environment map based on the comparison result And creates an environmental map based on the location information.

For example, if the travel distance calculated from the encoder is significantly smaller than the travel distance calculated from the optical flow sensor, the control unit 500 determines that the robot cleaner is passing through a slippery floor like a carpet, The sensor fusion is performed by determining the position based only on the position information of the gyroscope and the optical flow sensor or increasing the uncertainty of the encoder information.

On the other hand, since the image information which is the first position information generated from the first detection unit has a longer update period than the position information of the other detection units, the frequency of the sensor fusion is small, and the degree of brightness of the image information, Uncertainties can be adjusted. Further, even in a dark environment where the first detection unit can not operate, positional error can be reduced by using the position information of the second to third detection units or the second to fourth detection units.

As another example, when the robot cleaner travels in a place other than the floor of the plane, such as a threshold climb, the first position information and other position information greatly vary, so that the position detection error is largely generated and the uncertainty is also adjusted accordingly.

In addition, the robot cleaner includes a power unit 610 having a battery type power supply unit that can be charged, a traveling unit 620 having a plurality of wheels to move the robot cleaner, An input unit 640 for inputting data by having one or more buttons, an output unit 650 for displaying information on the current operation state and the setting mode, And a storage unit 660 for storing an environment map, a driving route, and the like.

The power supply unit 610 supplies the operating power for moving the robot cleaner and performing cleaning, and when the remaining battery level is insufficient, the charging current is supplied from the charging stand to charge the battery. The driving unit 620 includes a predetermined wheel motor for rotating the plurality of wheels including a plurality of main wheels and one or more auxiliary wheels, So that the robot cleaner is moved. The cleaning unit 630 includes a suction motor for washing the air and a means for agglomerating the dust, and sucks dust or foreign matter from the surroundings generated during traveling. In addition, the robot cleaner may further include an obstacle detection unit (not shown) for detecting obstacles in the vicinity of the robot cleaner. As the obstacle detecting unit, an infrared sensor (Infra-RED sensor), an ultrasonic sensor (Supersonic Wave Sensor), a RF sensor (Radio Frequency Sensor), a bumper or the like can be used.

Referring to FIG. 3, the method for detecting a position of a robot cleaner according to an exemplary embodiment of the present invention includes a first detecting step (S100) of detecting a position based on upper image information and outputting first position information, A second detecting step S200 of detecting a position based on the detected position of the wheel motor and outputting second position information, a third detecting step of detecting the position based on the rotation of the wheel motor driving the wheel and outputting the third position information (S500) for comparing two or more pieces of position information among the position information and determining a current position of the robot cleaner according to the comparison result. The method further includes a state determination step (S600) of determining a traveling state of the robot cleaner based on two or more position information among the position information. The method further includes an environment map generation step (S700) of generating an environment map based on the location information. Hereinafter, the configuration of the apparatus will be described with reference to Figs. 1 and 2. Fig.

The first detection step S100 includes an image capturing step S110 for capturing an image of an upper side and generating upper image information, a minutiae point extracting step S120 for extracting minutiae from the upper image information, And a first position information generating step (S130) for generating first position information by the first position information generating step.

The upper photographing process S100 photographs the upper side using the camera and generates the upper side image information from the captured upper side image. Here, the upward photographing process (S100) uses a lens having a wide angle of view such that all the areas above the predetermined position, for example, the entire area of the ceiling, can be photographed. For example, a lens having an angle of view of 160 degrees or more.

The minutiae point extracting step S120 extracts minutiae from an arbitrary landmark. In particular, minutiae points are extracted using natural markers such as fluorescent lights and interior structures existing in an upper region including a ceiling scene.

The minutiae point extraction process (S120) according to the present invention will be described with reference to FIG. The minutiae can be extracted after the image is photographed once. However, for convenience of explanation, the operation of picking up the minutiae by photographing twice during the movement will be described. 7, when the first mark C1 and the second mark N1 are compared with each other, the robot cleaner moves while the first time k and the second time k + 1) and the upper part including the ceiling scene, respectively. At this time, the first mark C1 and the second mark N1 in the upper image information photographed at the first time (k) and the second time (k + 1) are the first feature point M1 and the second feature point M2). At this time, the first mark C1 and the second mark N1 appear as a first feature point M1 (k) and a second feature point M2 (k). On the other hand, the first mark C1 and the second mark N1 at the second time (k + 1) are the first feature point M1 (k + 1) and the second feature point M2 (k + .

The first feature point M1 (k), the second feature point M2 (k), and the first feature point M1 (k (k)), which are feature points of the upper image information for the first mark C1 and the second mark N1, +1)) and the second feature point M2 (k + 1), respectively, and compares them to calculate the movement distance between the feature points. That is, as shown in FIG. 7C, the movement distance PL1 of the first feature point is compared with the feature point of the image information photographed at the first time k and the second time k + 1, And calculates the movement distance PL2 of two minutiae. At this time, the moving distance L1 between the first mark C1 and the second mark N1 and the robot cleaner according to the movement of the robot cleaner is constant and equal to the actual moving distance of the robot cleaner. However, the movement distances PL1 and PL2 of the feature points of the photographed image information are different from each other. As the distance of the mark increases, the travel distance of the minutiae to the mark is smaller, whereas the closer the mark is to the robot cleaner, that is, the lower the wall surface than the ceiling, the greater the difference in travel distance. Accordingly, when the moving ratio of the minutiae corresponding to the movement of the robot cleaner is equal to or larger than a predetermined ratio as in the second mark N1, it is judged to be an unnecessary minutia and removed.

Since the first mark C1 among the first mark C1 and the second mark N1 is located in the ceiling scene, the height of the second mark N1 is calculated using the distance from the robot cleaner to the ceiling scene , And when the calculated height is equal to or lower than the reference height, it is determined as an unnecessary feature point and removed. When the first feature point M1 and the second feature point M2 are compared, the movement distance PL1 of the first feature point M1 and the movement distance PL2 of the second feature point M2 with respect to the respective movement distances, 2 mark, and the ratio of the actual moving distance and height of the robot cleaner. At this time, since the actual moving distance is the same and the height of the first characteristic point M1 is the ceiling height, the height of the second characteristic point M2, i.e., the second mark N1, can be calculated. Here, it is determined that the feature points located in the central part of the captured upper image information are located in the ceiling scene, and the height of the feature points is calculated based on the feature points located in the center part.

The second detection step S200 includes a down-shooting process S210 for photographing downward and downward image information, and a second positional information generating process S230 for generating second positional information from the downward image information . The second detection step S200 may include a downward information determination step S220 for determining the state of the downward image information and a light amount adjustment process for adjusting the amount of light irradiated downward based on the determination result .

In the second detection step S200, the image sensor 210 provided on the back surface of the robot cleaner is used to photograph the bottom, that is, the floor during the movement of the robot cleaner. And downward image information of a predetermined format is generated from the photographed downward image (S210). The second detecting step S200 adjusts one or more light sources using the light amount adjusting unit 220 as necessary to irradiate light on a bottom surface area photographed by the image sensor 210 S220). In other words, when the robot cleaner moves on a flat floor, the image sensor 210 maintains a certain distance to the bottom surface. On the other hand, when the robot cleaner moves on the bottom surface of an uneven surface, It will move away. At this time, it is determined whether the downward image information generated in the downward image capturing process (S210) is normal or more than the reference image information (S220). If it is determined that there is an error, at least one light source is operated, . On the other hand, the second detection step S200 can detect a position that is robust against slip using the downward image information (S230).

The third detection step S300 detects the rotation speed of the wheel motor provided in the driving unit 620 of the robot cleaner to detect the rotation speed or the linear velocity (S310). The rotation speed or the linear velocity is detected as a double integral The third location information is generated using a predetermined operation (S320). The third detection step S300 generally uses an encoder.

According to another aspect of the present invention, there is provided a method of positioning a robot cleaner, the method further comprising a fourth detecting step (S400) of detecting a position based on direction information of the robot cleaner and outputting fourth position information. The description of other configurations is omitted from the description of the configuration of the position detection method according to the above example, and the following description is omitted.

That is, the fourth detection step (S400) detects the rotation speed, that is, the angular velocity (S410) by detecting a change in the direction of movement of the robot cleaner, and obtains fourth position information from the angular velocity through a predetermined operation such as double integration (S420). The fourth detection step (S400) generally uses a gyroscope (angular velocity sensor).

The first to third positional information, or the first to fourth positional information may be combined or selectively applied to precisely detect the position of the robot cleaner. For example, the robot cleaner can acquire feature points through image processing based on the first position information, draw an environmental map, and can detect the position of the robot cleaner based on the environmental map. However, The position error is generated due to inaccuracy of the environmental map due to slippage or collision. The position detection error may be detected by detecting the position of the robot cleaner from the velocity more easily by using the third positional information, using the fourth positional information, or using the third and fourth positional information together, By using the second position information which is resistant to slippage caused by a material or the like. On the other hand, only the detecting unit for detecting the relative position of the encoder as the third detecting unit 300 or the relative position of the gyroscope used as the fourth detecting unit 400 can be set to a condition such as a floor having a large slip of the wheel The optical flow sensor, which is the second detection unit 200, can generate the position information irrespective of the slip.

The state determination step S600 compares the position information generated from the first to third detection units or the first to fourth detection units to determine the running condition of the current robot cleaner, Sensor fusion is performed by selecting a combination or by adjusting the uncertainty of each sensor information. In addition, the position detecting method according to the present invention may further include an information comparing step (not shown) for comparing two or more pieces of position information among the position information, a map generating step (S700) for generating an environment map based on the comparison result, And creates an environment map based on the location information.

For example, in the position detecting method according to the present invention, if the travel distance calculated from the encoder is significantly smaller than the travel distance calculated from the optical flow sensor, it is determined that the robot cleaner is passing through a slippery floor like a carpet, Except for the encoder, the sensor fusion is performed by determining the position based only on the position information of the gyroscope and the optical flow sensor or increasing the uncertainty of the encoder information.

On the other hand, since the first location information has a longer update period than other location information, the frequency of the sensor fusion is small, and the uncertainty can be adjusted according to the brightness of the image information, the number of matching feature points, In addition, if the second to third position information or the second to fourth position information are used in a dark environment where it is difficult to obtain the first position information, the position recognition error can be reduced.

As another example, when the robot cleaner travels in a place other than the floor of the plane, such as a threshold climb, the first position information and other position information greatly vary, so that the position detection error is largely generated and the uncertainty is also adjusted accordingly.

As described above, the robot cleaner and the position detecting method according to the present invention include various sensors for detecting a change in position and attitude, determine the running condition of the robot cleaner according to the sensor information, It is possible to detect the position of the robot cleaner robustly by slipping, collision or the like by selecting a suitable sensor combination or by performing sensor fusion considering uncertainty, thereby generating a more precise environment map.

1 is a block diagram schematically illustrating the configuration of a robot cleaner according to the present invention;

Fig. 2 is a block diagram schematically showing a detailed configuration of the first detection unit of Fig. 1; Fig.

FIG. 3 is a block diagram schematically showing a detailed configuration of the second detection unit of FIG. 1; FIG.

4 is a flowchart schematically illustrating a method for detecting a position of a robot cleaner according to the present invention;

FIG. 5 is a flowchart illustrating an example of FIG. 4; FIG.

FIG. 6 is a perspective view showing the appearance of a robot cleaner according to the present invention; FIG.

7 is a view for explaining an operation of detecting second position information according to the present invention.

Claims (12)

A first detection unit for detecting a position based on the upward image information and outputting first position information; A second detection unit for detecting a position based on the downward image information and outputting second position information; A third detecting unit for detecting the position based on the rotation of the wheel motor that drives the wheel and outputting the third position information; And And a control unit for determining a current position of the robot cleaner based on two or more pieces of positional information of the positional information and determining a running state of the robot cleaner, The first detection unit includes: A camera for photographing an upper part and outputting upward video information, And an image processing unit that extracts a plurality of feature points from the upside image information and generates the first position information based on the extracted plurality of feature points, The second detection unit includes: An image sensor for photographing the downward direction and outputting downward image information, A distance measuring unit for measuring a distance from the image sensor to the floor, And a light amount adjusting unit for adjusting an amount of light irradiated downward based on the measured distance. The method according to claim 1, And a fourth detection unit for detecting the position based on the direction information of the robot cleaner and outputting the fourth position information. delete The method according to claim 1, Wherein the distance measuring unit comprises: A signal formed by at least one of an infrared ray and an ultrasonic wave is transmitted, And measures the distance from the image sensor to the bottom surface based on a time when the transmitted signal is reflected and returned. 3. The apparatus according to claim 1 or 2, A comparison unit for comparing two or more pieces of position information among the pieces of position information; And And a map generation unit for generating an environment map based on the comparison result. A first detecting step of detecting a position based on the upper image information and outputting first position information; A second detecting step of detecting a position based on the downward image information and outputting second position information; A third detecting step of detecting the position based on the rotation of the wheel motor driving the wheel and outputting the third position information; And And a positioning step of comparing two or more positional information among the positional information and determining a current position of the robot cleaner in accordance with the comparison result, Wherein the first detecting step comprises: An upper photographing process of photographing the upper part and generating the upper image information, A feature point extracting step of extracting a plurality of feature points from the upside image information, And a first position information generating step of generating the first position information based on the extracted plurality of feature points, Wherein the second detecting step comprises: A downward photographing process of photographing a downward direction and outputting downward image information, A second position information generating step of generating second position information from the downward image information, A distance measurement process for measuring the distance from the image sensor to the floor, And adjusting an amount of light irradiated downward based on the measured distance. The method according to claim 6, And a fourth detecting step of detecting the position based on the direction information of the robot cleaner and outputting the fourth position information. 8. The method according to claim 6 or 7, And determining a traveling state of the robot cleaner based on at least two of the position information. delete The method according to claim 6, The distance measuring process includes: A process of transmitting a signal formed of at least one of infrared rays and ultrasonic waves; And measuring a distance from the image sensor to a bottom surface based on a time when the transmitted signal is reflected and returned. 11. The method according to claim 10, A downward information determination process for determining a status of the downward video information, And adjusting a light amount irradiated downward on the basis of the determination result. 9. The method of claim 8, An information comparing step of comparing two or more pieces of position information among the pieces of position information; And And generating an environment map based on the comparison result.

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