KR20210094388A - Autonomous moving robot and method for controlling the same - Google Patents

Abstract

The present invention relates to an autonomous moving robot and a control method thereof, which can self-correct errors of a distance sensing unit whenever returning for charging. To this end, the autonomous moving robot comprises: a robot body having a power supply unit and a driving unit; a distance sensing unit provided on one side of the robot body to measure the distance from a surrounding environment of the robot body; a wheel sensor sensing a rotation number of the driving unit; and a control unit controlling the driving unit. The control unit aligns the robot body with a first position, calculates a measurement distance from the first position to a second position through the distance sensing unit, and calculates a moving distance from the first position to the second position of the robot body based on the rotation number sensed from the wheel sensor to determine whether to correct the distance sensing unit based on the measurement distance and the moving distance.

Description

Autonomous mobile robot and its control method

The present invention relates to an autonomous mobile robot and a method for controlling the same.

In general, robots have been developed for industrial use and have been responsible for a part of factory automation. Recently, the field of application of robots has been further expanded, and autonomous mobile robots that can be used in general households are also being made.

A representative example of the autonomous mobile robot is a robot cleaner, which is a kind of home appliance that cleans by sucking dust or foreign substances around it while traveling on its own in a predetermined area. Such a robot vacuum cleaner generally includes a rechargeable battery and an obstacle sensor capable of avoiding obstacles while driving, so that it can clean while driving by itself.

In order for the robot cleaner to run by itself, it is essential to recognize the position of the robot cleaner. Typically, the current position of the robot cleaner may be recognized using a map of an environment in which the robot cleaner operates and various sensor data.

However, when an unexpected position change of the sensor unit fixed to the main body of the robot cleaner occurs, the robot cleaner may not properly recognize its current position, relative distance, or direction. When the robot cleaner does not precisely recognize its current position, relative distance, or direction, the cleaning of the cleaning target area is not smooth and the number of uncleaned areas is increased.

In order to solve this problem, the following prior art has been proposed.

PCT Publication WO 2015/008874 Al (published on July 15, 2013)

According to the prior art as described above, a robot cleaner and a self-calibration method capable of performing diagnosis and self-calibration of a 3D sensor by extracting feature points are provided. However, the method of calibrating the 3D sensor by extracting the feature points of the prior art does not correct the actual moving distance of the robot cleaner, so there is a problem that an error may still occur.

PCT Publication WO 2015/008874 Al (published on July 15, 2013)

SUMMARY OF THE INVENTION An object of the present invention is to provide an autonomous mobile robot capable of accurately determining the position of a robot body by self-correcting a recognition distance error of a distance sensing unit, and a control method thereof.

An object of the present invention is to provide an autonomous mobile robot capable of accurately determining the position of a cleaner body by correcting an error of a distance sensing unit when the robot body returns to charging every time, and a method for controlling the same.

Another object of the present invention is to provide an autonomous mobile robot that detects a position through a distance sensing unit in which the actual moving distance of the robot body is reflected, based on the number of rotations of the driving unit sensed by the wheel sensor, and a control method thereof.

Another object of the present invention is to provide an autonomous mobile robot having a floor detection sensor and capable of more precisely correcting an error of the distance detection unit, and a method for controlling the same.

In order to solve the above problems, the self-calibration of the distance sensing unit based on the actual moved distance of the robot body can be performed every time the robot body returns to charge, thereby improving the reliability of the product.

In order to solve the above problems, an autonomous mobile robot according to an embodiment of the present invention includes: a robot body having a traveling unit; and a distance sensing unit provided on one surface of the robot body to measure a distance of the robot body to a surrounding environment; a wheel sensor for detecting the number of revolutions of the driving unit; and a control unit for controlling the driving unit.

The control unit aligns the robot body to a first position, calculates a measured distance from the first position to a second position through the distance sensing unit, and based on the number of rotations detected by the wheel sensor, the robot body By calculating a moving distance from the set position to the second position, it is possible to determine whether to calibrate the distance sensor based on the measured distance and the moving distance.

In addition, the robot body may be docked in a charging stand to charge the battery of the autonomous mobile robot, and the second position may be a position of one point of the charging stand.

In one embodiment, the charging base includes a charging body having a charging terminal, the second position is a position of one point of the charging body, and the control unit determines whether the robot body is docked to the charging body. It may be determined whether the robot body has reached the second position based on the determination.

In another embodiment, the charging base includes a charging body and a charging base extending by a predetermined length in front of the charging body, the second position is a position of an end of the charging base, and the robot body is the robot body and a floor detection sensor for obtaining downward information of , and the control unit may determine whether the robot body reaches the second position from the detection of the end of the base by the floor detection sensor.

In this case, the control unit may detect a distance from the first position to the charging body through the distance sensing unit, and calculate the measured distance by subtracting the length of the charging base from the sensed distance. there is.

Also, the controller may calibrate the distance sensor when an absolute value of a difference between the measured distance and the moving distance is greater than a reference value.

In an embodiment, the robot body may include a data unit for storing information on the moving distance, and the controller may calibrate the distance sensing unit based on an average value of the moving distance stored in the data unit.

In another embodiment, the controller may calibrate the distance sensor based on the moving distance value.

In addition, the control unit may determine whether the robot body returns to the charging station.

At this time, when the control unit determines to return to the charging station, the control unit may align the robot body to the first position.

In order to solve the above problems, a method for self-calibrating a distance sensing unit of an autonomous mobile robot according to an embodiment of the present invention includes: aligning the autonomous mobile robot to a first preset position and direction; measuring a measurement distance from the first position to a second position through a distance sensing unit; entering the autonomous mobile robot toward the second position; detecting whether the second location has been reached; measuring a moving distance from the first position to the second position based on the number of rotations of the driving unit of the autonomous mobile robot; determining whether calibration of the distance sensing unit is necessary based on the measured distance and the moving distance; and when it is determined that calibration is necessary, calibrating the distance sensing unit.

According to the embodiment of the present invention having the above configuration, it is possible to provide an autonomous mobile robot capable of accurately determining the position of the robot body by self-correcting the recognition distance error of the distance sensing unit.

In particular, there is an advantage in that the position of the robot body can be precisely determined by correcting the error of the distance sensing unit when the robot body returns to charging every time.

In addition, it is possible to provide an autonomous mobile robot that detects movement through a distance sensor in which the distance of the actual robot body is reflected based on the number of rotations of the driving unit sensed by the wheel sensor.

In addition, by providing a floor detection sensor, there is an advantage in that the error of the distance detection unit can be more precisely corrected.

1 is a view showing a state in which an autonomous mobile robot according to an embodiment of the present invention is aligned at a predetermined position in front of a charging station.
2 is a diagram illustrating a state in which an autonomous mobile robot is docked on a charging stand according to an embodiment of the present invention.
3 is a block diagram illustrating main parts of an autonomous mobile robot and a charging station according to an embodiment of the present invention.
4 is a block diagram illustrating configurations of a sensor unit according to an embodiment of the present invention.
5 is a flowchart illustrating a self-calibration method of a distance sensing unit of an autonomous mobile robot according to an embodiment of the present invention.
6 is a view showing a state in which an autonomous mobile robot is aligned at a predetermined position in front of a charging station according to another embodiment of the present invention.
7 is a view showing a state in which the charging base of the floor detection sensor is sensed according to another embodiment of the present invention.
8 is a flowchart illustrating a self-calibration method of a distance sensing unit of an autonomous mobile robot according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated on different drawings. In addition, in describing the embodiment of the present invention, if it is determined that a detailed description of a related known configuration or function interferes with the understanding of the embodiment of the present invention, the detailed description thereof will be omitted.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the components from other components, and the essence, order, or order of the components are not limited by the terms.

In addition, it cannot be said that the spirit of the present invention is limited to the presented embodiment, and other embodiments included within the scope of the spirit of the present invention can be easily proposed by adding, changing, or deleting other components.

The autonomous mobile robot according to the present invention may include a robot cleaner, an airport guide robot, and the like. Hereinafter, the robot cleaner will be described as an example.

1 is a view showing a state in which an autonomous mobile robot according to an embodiment of the present invention is aligned at a predetermined position in front of a charging base, and FIG. 2 is a view showing a state in which the autonomous mobile robot of this embodiment is docked to the charging stand.

Referring to FIG. 1 , a robot cleaner 10 , which is an autonomous mobile robot according to an embodiment of the present invention, moves along the floor of a cleaning area and can suck foreign substances. The robot cleaner 10 may be docked on the charging stand 20 to charge the battery of the power supply unit 130 to be described later.

The robot cleaner 10 may include a robot body 11 that forms an exterior of the robot cleaner 10 and forms a space in which parts constituting the robot cleaner 10 are accommodated.

A suction unit (not shown) may be provided inside the robot body 11 so that the robot cleaner 10 can move and clean foreign substances. The suction unit may include a suction motor generating a suction force, a suction port through which the airflow generated by the suction motor is sucked, a dust separator for separating foreign substances from the airflow sucked through the suction port, and a foreign material separated by the dust separator It may include a foreign matter dust bin in which they accumulate.

The robot cleaner 10 includes a traveling unit 110 rotatably provided to the robot body 11 . The driving unit 110 may include a left wheel and a right wheel. As the traveling unit 110 rotates, the robot body 11 may move along the floor of the cleaning area, and in this process, foreign substances are sucked through the suction unit.

Also, the robot cleaner 10 may include a distance sensing unit 121 .

The distance sensing unit 121 may be disposed in front of the robot body 11 . Alternatively, the distance sensing unit 121 may be disposed on the upper surface of the main body 11 of the cleaner.

The distance sensing unit 121 may be fixedly installed on the robot body 11 , or may be installed so that the direction in which the distance sensing unit 121 is directed can be changed.

The distance sensing unit 121 may detect an object, particularly an obstacle, existing in the moving direction of the robot cleaner 10 and transmit information obtained by measuring the distance to the object to the controller 170 to be described later.

The distance sensing unit 121 may include a 3D sensor unit. For example, the 3D sensor unit may include a camera module and a laser module. The camera module may be a three-dimensional depth camera (3D Depth Camera) for calculating the distance between the robot cleaner and the object to be photographed. The laser module may be installed adjacent to the camera module. The laser module may irradiate a laser line to an object photographed by the camera module.

In one example, the 3D sensor unit receives a portion of the laser emitted from the laser module reflected from the object to be photographed, and by analyzing the received laser, it is possible to measure the distance between the robot body 11 and the object to be photographed. . The distance sensing unit 121 may use a time of flight (TOF) method.

In an embodiment, the distance sensing unit 121 may be any one or more of LiDar, laser, IR, ultrasound, and vision depth, but is not limited thereto.

In addition, the robot cleaner 10 is provided with a power supply unit 130 (refer to FIG. 3 ), and the power supply unit 130 may include a rechargeable battery. Accordingly, the components constituting the robot cleaner 10 may receive power from the battery, and thus, in a state in which the battery is charged, the robot cleaner 10 is electrically separated from commercial power. driving is possible

The charging station 20 may be connected to a commercial power source to supply a charging current to the power supply unit 130 to charge the battery.

The charging stand 20 may include a charging body 210 and a charging base 220 . The charging body 210 may include a charging terminal 211 and a return induction sensor 212 (see FIG. 3 ).

When the power supply unit 130 of the robot cleaner 10 is docked to the charging terminal 211 and electrically connected to the commercial power source, the battery may be charged.

The return induction sensor 212 is provided in the charging body 210 , and transmits a return signal indicating a direction and a distance so that the robot cleaner 10 can return to the charging stand 20 .

The charging base 220 forms the bottom surface of the charging stand 210 , and may be formed to extend forward from the charging body 210 to support the robot body 11 . For example, the charging base 220 may be formed to extend from the charging body 210 by a predetermined length (L).

Referring to FIG. 2 , the robot cleaner 10 is docked with the charging body 210 by traveling to the upper surface of the charging base 220 when charging is returned. Accordingly, the charging base 220 may stably support the robot body 11 when the robot cleaner 10 is docked and charged to the charging body 210 .

The end of the charging base 220 may be formed to be rounded so that the robot body 11 can easily travel to the upper surface of the charging base 220 .

3 is a block diagram illustrating main parts of a robot cleaner and a charging base according to an embodiment of the present invention, and FIG. 4 is a block diagram illustrating the configuration of a sensor unit according to an embodiment of the present invention.

As shown in the drawing, the robot cleaner 10 may further include a driving unit 140 for driving the traveling unit 110 .

The robot cleaner 10 may further include a signal receiving unit 150 , a sensor unit 120 , a data unit 160 , and a control unit 170 controlling overall operations.

The sensor unit 120 may include some or all of the distance sensing unit 121 , the floor sensing sensor 122 , the wheel sensor 123 , and the auxiliary sensor unit 124 .

The driving unit 140 may drive the driving unit 110 . Specifically, the driving unit 140 may include a first driving motor rotating the left wheel and a second driving motor rotating the right wheel.

Accordingly, through the independent control of the first driving motor and the second driving motor, the robot cleaner 10 may move forward, backward, or turn.

For example, when the first driving motor and the second driving motor rotate in the same direction, the robot cleaner 10 may travel straight, and the first driving motor and the second driving motor have different speeds. When rotated to or rotated in opposite directions, the traveling direction of the robot cleaner 10 may be switched.

The signal receiver 150 detects an external signal. The signal receiver 150 may include, for example, an infrared sensor, an ultrasonic sensor, and a radio frequency sensor. The robot cleaner 10 may receive a return signal from the return induction sensor 212 of the charging stand 20 using the signal receiving unit 150 to determine the position and direction of the charging stand 20 . .

Specifically, the return induction sensor 212 of the charging station 20 transmits a return signal indicating a direction and a distance so that the robot cleaner 10 can return to the charging station 20 . The robot cleaner 10 may receive the return signal through the signal receiving unit 150, determine the current position through the control unit 170 to be described later, set the moving direction, and return to the charging station 20. .

As described above, the distance sensing unit 121 may detect an object, particularly an obstacle, existing in the moving direction of the robot cleaner 10 and transmit the acquired image and detection information to the controller 170 to be described later.

The floor detection sensor 122, in other words, the Cliff Sensor, uses various types of optical sensors. In this embodiment, an infrared sensor will be described as an example. The floor detection sensor 122 may have the form of an infrared sensor module having a light emitting unit and a light receiving unit like a PSD sensor.

The floor detection sensor 122 may have a reference distance and a detection range. For example, the floor detection sensor 122 may obtain a stable measurement value regardless of a difference in reflectance and color of the floor using a triangulation method. The floor detection sensor 122 may be an infrared sensor having a light emitting unit and a light receiving unit, an ultrasonic sensor, an RF sensor, a Position Sensitive Detector (PSD) sensor, and the like.

The floor detection sensor 122 continuously detects the floor while the robot cleaner 10 moves. As an example, the floor detection sensor 122 may detect an end of the charging base 220 of the robot cleaner 10 .

A wheel sensor 123 may be connected to the driving unit 110 to detect the number of rotations of the driving unit 110 . Specifically, the wheel sensor 123 may be respectively connected to the left wheel and the right wheel. Here, the wheel sensor 123 may be a rotary encoder.

The rotary encoder detects and outputs the number of rotations of the left wheel and the right wheel when the robot cleaner 10 is moving. The controller 170, which will be described later, may calculate the traveling speed and the moving distance of the robot cleaner 10 by using the rotation speed.

The auxiliary sensor unit 124 may detect an obstacle in front of the robot cleaner 10 , that is, in a driving direction, using at least one of a laser, an ultrasonic wave, and an infrared ray. When the transmitted signal is reflected and incident, the auxiliary sensor unit 124 inputs information on whether an obstacle exists or a distance to the obstacle as an obstacle detection signal to the control unit 170 to be described later. However, a configuration in which the auxiliary sensor unit 124 is omitted is also possible.

The data unit 160 stores various signals input from the sensor unit 120 . For example, reference data for the control unit 170 to be described later to determine an obstacle may be stored in the data unit 160 , and obstacle information such as a distance and size of the detected obstacle may be stored.

In addition, control data for controlling the operation of the robot cleaner 10 and data according to the cleaning mode of the robot cleaner 10 are stored in the data unit 160 , and a map including obstacle information is stored.

The data unit 160 may include a hard disk drive (HDD), a solid state disk (SSD), a silicon disk drive (SDD), a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device. there is.

The control unit 170 may control the driving unit 140 to move the robot cleaner 10 . Through the control unit 170, the driving unit 140 independently controls the operation of the first driving motor and the second driving motor of the driving unit 110 to allow the robot cleaner 10 to travel in a straight line or by rotating. can

The control unit 170 stores the signal detected by the sensor unit 120 in the data unit 160, and analyzes the signal to determine the position of the robot cleaner 10, whether there is an obstacle, and the distance to the obstacle. etc. can be judged.

Specifically, the control unit 170 compares and analyzes the acquired image data input from the distance sensing unit 121 over time to calculate a moving distance and a moving direction, thereby calculating the position of the robot cleaner 10 . can do.

For example, the controller 170 may extract a feature point from the acquired image data input from the distance sensor 121 , and calculate the position of the robot cleaner 10 using the feature point, and You can create a cleaning map for

As another example, the control unit 170 may measure the distance between the robot cleaner 10 and the object to be photographed by analyzing the laser received from the distance sensing unit 121 .

The control unit 170 measures the infrared angle between the light emitting signal of the infrared light emitted by the floor detection sensor 122 toward the ground and the reflected signal received by being reflected by the obstacle to detect the cliff and analyze its depth. there is.

In addition, the control unit 170 measures the infrared angle between the light emitting signal of the infrared light emitted toward the ground by the floor detection sensor 122 and the reflected signal received by being reflected by the obstacle, and removes the obstacle protruding from the floor. can detect

The control unit 170 calculates the traveling speed of the robot cleaner 10 and the moving distance of the robot cleaner 10 that are moving through the number of revolutions of the traveling unit 110 detected by the wheel sensor 123 . can

Also, the control unit 170 may precisely recognize the position of the robot cleaner 10, the presence of an obstacle, and the distance to the obstacle using the obstacle detection signal detected through the auxiliary sensor unit 124 . .

The control unit 170 may determine the remaining amount and charging state of the battery of the power unit 130 . When it is determined that the remaining power of the battery is insufficient, the control unit 170 may move the robot cleaner 10 to the charging stand 20 .

In this case, the control unit 170 may determine the position of the charging stand 20 through the return signal of the return induction sensor 212 sensed through the signal receiving unit 150 . After locating the charging stand 20 , the control unit 170 may control the driving unit 140 to align the robot body 11 to a preset position for smooth charging return, and then return charging.

When cleaning of the set designated area is completed, the control unit 170 may store the cleaning record in the data unit 160 .

Hereinafter, a self-calibration method of the distance sensing unit 121 when the robot cleaner 10, which is an example of the autonomous mobile robot of the present invention, returns to charge will be described.

5 is a flowchart illustrating a method for self-calibrating a distance sensing unit of an autonomous mobile robot according to an embodiment of the present invention.

The robot cleaner 10, which is an autonomous mobile robot according to an embodiment of the present invention, may be driven in a plurality of driving modes. The plurality of driving modes may include, for example, a cleaning mode, a driving mode, a standby mode, a charging return mode, and a charging mode.

The control unit 170 of the robot cleaner 10 determines whether it is necessary to return to the charging station 20 while driving.

The need to return to the charging station 20 may be, for example, when it is determined that the remaining power of the battery is insufficient or when cleaning is completed.

When it is necessary to return to the charging station 20, the robot cleaner 10, which is an autonomous mobile robot, receives a return signal from the return induction sensor 212 of the charging station 20 through the signal receiving unit 150. The location of the charging stand 20 is identified (S10).

The robot cleaner 10 aligns the robot cleaner 10 to a first position and direction, which is a preset reference position, based on the identified position of the charging station 20 ( S20 ).

The robot cleaner 10 aligned at the first position measures a first distance D1, which is a measurement distance to a point of the charging station 20, using the distance sensing unit 121 (S30). For example, the first distance may be a distance from the first position to a point of the charging body 210 .

In this case, the controller 170 may store the calculated first distance in the data unit 160 .

After calculating the first distance, the robot cleaner 10 returns to the charging station 20 while moving from the first position toward the charging station 20 (S40).

In this case, the robot cleaner 10 may store the return start time in the data unit 160 .

In the process of moving the robot cleaner 10 toward the charging station 20 , the control unit 170 may determine the number of rotations of the traveling unit 110 detected by the wheel sensor 123 , and the rotation Through the number, the moving distance of the robot cleaner 10 may be calculated.

The control unit 170 may detect the completion time of docking to the charging terminal 211 of the charging stand 20 of the robot cleaner 10 (S50). In this case, the controller 170 may store the docking completion time in the data unit 160 .

The control unit 170 is a second movement distance that the robot cleaner 10 moves based on the number of revolutions of the traveling unit 110 from the return start time of the robot cleaner 10 to the docking completion time. The distance can be calculated (S60). For example, the second distance may be a moving distance of the robot cleaner 10 from the first position to the charging body 210 .

In this case, the controller 170 may store the calculated second distance in the data unit 160 . A plurality of second distance data input each time the robot cleaner 10 returns to charge may be stored in the data unit 160 . Also, in the data unit 160 , a second distance average value calculated from the plurality of second distance data may be stored.

The control unit 170 may compare the absolute value of the difference between the first distance and the second distance with a reference value to determine whether the distance sensing unit 121 needs to be calibrated (S70).

More specifically, the reference value, which is an allowable value of a difference between the measured distance and the moving distance, may be stored in the data unit 160 . When the absolute value of the difference between the first distance and the second distance is smaller than the reference value, the control unit 170 may determine that the distance sensing unit 121 needs to be calibrated.

As a result of the determination of the control unit 170 , when the distance sensing unit 121 needs to be calibrated, the control unit 170 may calibrate the distance sensing unit 121 ( S80 ).

In an embodiment, the control unit 170 may calibrate the distance sensing unit 121 based on the second average distance value stored in the data unit 160 . In more detail, the control unit 170 calibrates the distance sensing unit 121 based on a second distance average value that is an average value of the plurality of second distance data calculated every time the robot cleaner 10 returns to charging. can

For example, a correction coefficient corresponding to the difference between the first distance sensed by the distance detecting unit 121 and the average value of the second distance is calculated, and the first distance detected by the distance detecting unit 121 later Finally, a corrected first distance may be obtained by applying a correction coefficient to . Accordingly, the correction coefficient may be calculated at every charging return.

In another embodiment, the control unit 170 may calibrate the distance sensing unit 121 based on the second distance.

For example, a correction coefficient corresponding to the difference between the first distance and the second distance sensed by the distance detecting unit 121 is calculated, and the first distance detected by the distance detecting unit 121 is calculated later. A correction coefficient may be applied to finally obtain a corrected first distance. Accordingly, the correction coefficient may be calculated at every charging return.

Accordingly, it is possible to improve the distance sensing accuracy and reliability of the distance sensing unit 121 every time the robot cleaner 10 returns to charging.

Hereinafter, another embodiment of the present invention will be described.

Another embodiment of the present invention is different from the above-described embodiment in measuring the distance to the end of the charging base 210 of the robot cleaner 10 to calibrate the distance sensing unit 121 .

In addition, in another embodiment of the present invention, the drawings and reference numerals of the above embodiments are referred to.

6 is a view showing a state in which the autonomous mobile robot is aligned at a predetermined position in front of the charging station according to another embodiment of the present invention, and FIG. 7 is a view showing the charging base of the floor sensor according to another embodiment of the present invention. 8 is a flowchart illustrating a self-calibration method of a distance sensing unit of an autonomous mobile robot according to another embodiment of the present invention.

The control unit 170 of the robot cleaner 10 determines whether it is necessary to return to the charging station 20 while driving.

The need to return to the charging station 20 may be, for example, when it is determined that the remaining power of the battery is insufficient or when cleaning is completed.

When it is necessary to return to the charging station 20, the robot cleaner 10 receives a return signal from the return induction sensor 212 of the charging station 20 through the signal receiving unit 150 to receive the charging station 20 ) to determine the location (S10).

The robot cleaner 10 aligns the robot cleaner 10 to a preset first position and direction based on the identified position of the charging station 20 ( S20 ).

The robot cleaner 10 aligned at the first position measures the distance to the end of the charging base 220 using the distance sensing unit 121, and uses the measured distance from the first position A horizontal distance (third distance) to the end of the charging base 220 may be measured (S30a).

That is, the robot cleaner 10 may calculate a third distance that is a measurement distance corresponding to a horizontal distance from the first position to the end of the charging base 220 through the distance sensing unit 121 .

In this case, the controller 170 may store the calculated third distance in the data unit 160 .

After calculating the third distance, the robot cleaner 10 returns to the charging station 20 (S40).

In this case, the robot cleaner 10 may store the return start time in the data unit 160 .

In the process of moving the robot cleaner 10 toward the charging station 20 , the control unit 170 may determine the number of rotations of the traveling unit 110 detected by the wheel sensor 123 , and the rotation Through the number, the moving distance of the robot cleaner 10 may be calculated.

The control unit 170 may detect the completion time of arrival of the robot cleaner 10 to the end of the charging base 210 through the floor detection sensor 122 (S50a).

In this case, the control unit 170 may store the completion time of reaching the end of the charging base 210 in the data unit 160 .

The control unit 170 moves the robot cleaner 10 based on the number of revolutions of the traveling unit 110 from the starting point of the return of the robot cleaner 10 to the completion of reaching the end of the charging base 210 . A fourth distance that is one moving distance may be calculated (S60a).

For example, the fourth distance may be a moving distance of the robot cleaner 10 from the first position to the end of the charging base 220 .

In this case, the controller 170 may store the calculated fourth distance in the data unit 160 .

A plurality of fourth distance data input each time the robot cleaner 10 returns to charge may be stored in the data unit 160 . Also, in the data unit 160 , a fourth distance average value calculated from the plurality of fourth distance data may be stored.

The control unit 170 may compare the absolute value of the difference between the third distance and the fourth distance with a reference value to determine whether the distance sensing unit 121 needs to be calibrated (S70a).

More specifically, the reference value, which is an allowable value of a difference between the measured distance and the moving distance, may be stored in the data unit 160 . When the absolute value of the difference between the third distance and the fourth distance is smaller than the reference value, the controller 170 may determine that the distance sensing unit 121 needs to be calibrated.

As a result of the determination of the control unit 170 , when the distance sensing unit 121 needs to be calibrated, the control unit 170 may calibrate the distance sensing unit 121 ( S80 ).

In an embodiment, the control unit 170 may calibrate the distance sensing unit 121 based on the fourth average distance value stored in the data unit 160 . In more detail, the control unit 170 may calibrate the distance sensing unit 121 based on a 4 distance average value that is an average value of the plurality of fourth distance data calculated every time the robot cleaner 10 returns to charging. there is.

For example, a correction coefficient corresponding to the difference between the third distance sensed by the distance detecting unit 121 and the average value of the fourth distance is calculated, and the third distance detected by the distance detecting unit 121 later Finally, a corrected third distance may be obtained by applying a correction coefficient to . Accordingly, the correction coefficient may be calculated at every charging return.

In another embodiment, the control unit 170 may calibrate the distance sensing unit 121 based on the fourth distance. For example, a correction coefficient corresponding to the difference between the third distance and the fourth distance sensed by the distance detecting unit 121 is calculated, and the third distance detected by the distance detecting unit 121 is calculated later. Finally, a corrected third distance may be obtained by applying a correction coefficient. Accordingly, the correction coefficient may be calculated at every charging return.

Accordingly, it is possible to improve the accuracy and reliability of the distance detection of the distance sensing unit 121 every time the robot cleaner 10 more precisely returns to charging.

Hereinafter, another embodiment of the present invention will be described.

Another embodiment of the present invention measures the distance to a point of the charging stand 20 of the robot cleaner 10 through the distance sensing unit 121, and the distance sensing unit There is a difference in correcting (121).

In addition, in another embodiment of the present invention, the drawings and reference numerals of the other embodiments described above are used.

In another embodiment of the present invention, the robot cleaner 10 aligned to the first position is a distance (D1, see FIG. 1) to a point of the charging station 20 using the distance sensing unit 121. and calculates a fifth distance that is a value obtained by subtracting the length (L, see FIG. 1 ) of the charging base 220 stored in the data unit 160 from the measured value

Accordingly, the fifth distance may be a distance from the first position to the end of the charging base 220 .

In this case, the controller 170 may store the calculated fifth distance in the data unit 160 .

The control unit 170 may compare the absolute value of the difference between the fifth distance and the fourth distance with a reference value to determine whether the distance sensing unit 121 needs to be calibrated (S70a).

More specifically, the reference value, which is an allowable value of a difference between the measured distance and the moving distance, may be stored in the data unit 160 . When the absolute value of the difference between the fifth distance and the fourth distance is smaller than the reference value, the controller 170 may determine that the distance sensing unit 121 needs to be calibrated.

As a result of the determination of the control unit 170 , when the distance sensing unit 121 needs to be calibrated, the control unit 170 may calibrate the distance sensing unit 121 ( S80 ).

In an embodiment, the control unit 170 calculates a correction coefficient corresponding to a difference value between the fifth distance and the fourth distance average value detected by the distance sensing unit 121 , and later the distance sensing unit 121 . ), a correction coefficient may be applied to the detected fifth distance to finally obtain a corrected fifth distance. Accordingly, the correction coefficient may be calculated at every charging return.

In another embodiment, the control unit 170 may calibrate the distance sensing unit 121 based on the fourth distance. For example, a correction coefficient corresponding to the difference value between the fifth distance and the fourth distance sensed by the distance detecting unit 121 is calculated, and the fifth distance detected by the distance detecting unit 121 is calculated later. Finally, a corrected fifth distance may be obtained by applying a correction coefficient. Accordingly, the correction coefficient may be calculated at every charging return.

It is to be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be indicated by the appended claims rather than the foregoing detailed description. And all changes and modifications derived from the meaning and scope of the claims to be described later as well as equivalent concepts should be construed as being included in the scope of the present invention.

10 robot vacuum cleaner
110 drive
120 sensor unit
130 power supply
140 drive
150 signal receiver
160 data part
170 control
20 charging stand

Claims (16)

a robot body having a power supply unit having a battery and a battery charging terminal and a driving unit;
a distance sensing unit provided on one surface of the robot body to measure a distance of the robot body to the surrounding environment;
a wheel sensor for detecting the number of revolutions of the driving unit; and
A control unit for controlling the driving unit,
The control unit aligns the robot body to a first position, and calculates a measurement distance from the first position to the second position through the distance sensing unit,
Calculating the moving distance from the first position to the second position of the robot body based on the number of revolutions detected by the wheel sensor,
An autonomous mobile robot that determines whether to calibrate the distance sensing unit based on the measured distance and the moving distance. The method of claim 1,
The robot body can be docked in a charging stand to charge the battery,
The second position is an autonomous mobile robot, characterized in that it is a position of one point of the charging station. 3. The method of claim 2,
The charging stand includes a charging body having a charging terminal,
The second position is a position of one point of the charging body,
The control unit is an autonomous mobile robot that determines whether the robot body has reached the second position based on whether the robot body is docked to the charging body. 3. The method of claim 2,
The charging stand includes a charging body and a charging base extending in front of the charging body,
the second position is the position of the end of the charging base;
The robot body includes a floor detection sensor that acquires downward information of the robot body,
The control unit is an autonomous mobile robot that determines whether the second position of the robot body has been reached based on the detection of the end of the base by the floor detection sensor. 5. The method of claim 4,
The control unit detects a distance from the first position to the charging body based on the information obtained from the distance sensing unit,
An autonomous mobile robot that calculates the measured distance by subtracting the length of the charging base from the detected distance. The method of claim 1,
The control unit may be configured to calibrate the distance sensing unit when an absolute value of a difference between the measured distance and the moving distance is greater than a reference value. 7. The method of claim 6,
The robot body includes a data unit for storing information on the moving distance,
The control unit is an autonomous mobile robot that calibrates the distance sensing unit based on an average value of the moving distances stored in the data unit. 7. The method of claim 6,
The control unit is an autonomous mobile robot that calibrates the distance sensing unit based on the moving distance value. 3. The method of claim 2,
The control unit determines whether the robot body needs to return to the charging station,
When the control unit determines to return to the charging station, the autonomous mobile robot aligns the robot body to the first position. The method of claim 1,
The distance sensing unit is an autonomous mobile robot that is at least one of LiDar, laser, IR, ultrasound, and vision depth. 11. The method according to any one of claims 1 to 10,
The autonomous mobile robot is an autonomous mobile robot that is a robot cleaner. aligning the autonomous mobile robot to a preset first position;
measuring a measurement distance from the first position to a second position through a distance sensing unit;
entering the autonomous mobile robot toward the second position;
detecting whether the second location has been reached;
measuring a moving distance from the first position to the second position based on the number of rotations of the driving unit of the autonomous mobile robot;
determining whether calibration of the distance sensing unit is necessary based on the measured distance and the moving distance; and
When it is determined that calibration is necessary, the method of controlling an autonomous mobile robot comprising the step of calibrating the distance sensing unit. 13. The method of claim 12,
The autonomous mobile robot may be docked on a charging stand to charge the battery of the robot cleaner,
The second position is a position of one point of the charging body formed on the charging stand,
A control method of an autonomous mobile robot for determining whether to reach the second position based on whether the autonomous mobile robot is docked with the charging station. 13. The method of claim 12,
The autonomous mobile robot may be docked on a charging stand to charge the battery of the autonomous mobile robot,
The charging station includes a charging body and a charging base end extending forwardly from the charging body,
the second position is a position of the charging base end;
A control method of an autonomous mobile robot for determining whether to arrive at the second position based on detection of the charging base end of a floor detection sensor provided in the autonomous mobile robot. 15. The method of claim 14,
Measuring the moving distance to the second position comprises:
detecting a distance from the first position to a point of the charging body through the distance sensing unit; and
and calculating the measured distance by subtracting the length of the charging base from the sensed distance. 14. The method of claim 13,
In the step of determining whether the calibration is necessary, if the absolute value of the difference between the measured distance and the moving distance is greater than a reference value, it is determined that calibration of the distance sensing unit is necessary,
In the step of calibrating the distance sensing unit, the control method of the autonomous mobile robot for calibrating the distance sensing unit based on the moving distance or an average value of the moving distance stored in the data unit.

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