KR102440437B1 - Moving robot and its detecting uneven surface method - Google Patents

Abstract

Disclosed is a rough surface detection method of a moving robot which can detect a rough surface by checking a speed change of a moving robot. The rough surface detection method of a moving robot comprises: a step in which the moving robot calculates an overall average speed during driving time of the moving robot when the moving robot determines that driving of the moving robot is constant-speed driving; a step in which the moving robot compares section average speeds corresponding to a plurality of time intervals and the overall average speed; a step in which the moving robot checks a first time interval corresponding to a first section average speed among the section average speeds when the difference between the first section average speed and the overall average speed is higher than or equal to an arbitrary speed difference; and a step in which the moving robot checks the position of the moving robot at the checked first time interval, and detects the checked position of the moving robot as a rough surface.

Description

{Moving robot and its detecting uneven surface method}

The present invention relates to a mobile robot and a method for detecting an uneven surface thereof, and more particularly, to a mobile robot capable of detecting an uneven surface by checking a change in speed of the mobile robot, and a method for detecting an uneven surface thereof.

Mobile robots may travel on uneven as well as flat surfaces.

When a conventional mobile robot travels on an uneven floor, a damper or a shock absorber such as a suspension is used to reduce vibration of the mobile robot. However, parts of shock absorbers such as dampers and suspensions are expensive and difficult to install. In addition, over time, the life of the parts shortens, requiring replacement of the parts.

Korean Patent Publication No. 10-2220865 (2021.02.22.)

An object of the present invention is to provide a mobile robot capable of detecting a non-smooth surface by checking the speed change of the mobile robot, and a method for detecting a non-smooth surface thereof.

The method for detecting an uneven surface of a mobile robot according to an embodiment of the present invention includes the steps of, by the mobile robot, determining whether the movement of the mobile robot in space is a constant speed running, an accelerated running, or a decelerated running, the mobile robot is the mobile robot When it is determined that the traveling is the constant speed traveling, the mobile robot calculates an overall average speed during the traveling time of the mobile robot, and the mobile robot calculates the average speed of each section corresponding to a plurality of time intervals and the entire comparing the average speed, when the difference between the first section average speed and the overall average speed among the section average speeds is greater than or equal to a certain speed difference, the mobile robot performs a first time interval corresponding to the first section average speed confirming, and the mobile robot confirming the position of the mobile robot in the identified first time interval, and detecting the identified position of the mobile robot as a non-smooth surface.

In the method for detecting an uneven surface of the mobile robot, when the difference between the second section average speed and the overall average speed among the section average speeds is equal to or greater than the arbitrary speed difference, the mobile robot detects a speed corresponding to the second section average speed. checking a second time interval, the mobile robot checking a difference between a start time of the first time interval and an end time of the second time interval, and the mobile robot checking a start time of the first time interval When the difference between the start time of the first time interval and the end time of the second time interval is less than a certain time, the mobile robot determines the difference between the start time of the first time interval and the end time of the second time interval, and among the plurality of time intervals The method may further comprise calculating the size of the uneven surface by multiplying the interval average velocity at any time interval.

The first time interval and the second time interval are consecutive time intervals.

In any time interval among the plurality of time intervals, the section average speed is the section average speed when the mobile robot travels at a constant speed.

The method for detecting an uneven surface of a mobile robot according to another embodiment of the present invention includes the steps of: determining, by the mobile robot, whether the traveling of the mobile robot is a constant speed traveling, an accelerated traveling, or a decelerating traveling; When it is determined that the driving is the accelerated driving, the mobile robot calculates an overall average acceleration during the driving time of the mobile robot, and the mobile robot calculates the average acceleration for each section corresponding to a plurality of time intervals and the overall average. Comparing the accelerations, when the difference between the first section average acceleration and the overall average acceleration among the section average accelerations is greater than or equal to an arbitrary acceleration difference, the mobile robot checks a time interval corresponding to the first section average acceleration and confirming, by the mobile robot, the position of the mobile robot at the identified time interval, and detecting the identified position of the mobile robot as a non-smooth surface.

A mobile robot according to an embodiment of the present invention includes an acceleration sensor, a processor executing instructions for controlling operations of the mobile robot, and a memory storing the instructions.

The commands determine whether the traveling of the mobile robot is a constant speed traveling, an accelerated traveling, or a decelerated traveling, and when determining that the traveling of the mobile robot is the constant speed traveling, calculate the overall average speed during the traveling time of the mobile robot and compares each of the section average speeds corresponding to a plurality of time intervals and the overall average speed, and when the difference between the first section average speed and the overall average speed among the section average speeds is greater than or equal to an arbitrary speed difference, A first time interval corresponding to the first interval average speed is identified.

It is implemented to confirm the position of the mobile robot in the confirmed first time interval, and to detect the identified position of the mobile robot as a non-smooth surface.

A mobile robot according to another embodiment of the present invention includes an acceleration sensor, a processor for executing instructions for controlling operations of the mobile robot, and a memory for storing the instructions.

The commands determine whether the traveling of the mobile robot is a constant speed traveling, an accelerated traveling, or a decelerated traveling, and when it is determined that the traveling of the mobile robot is the accelerated traveling, the mobile robot is The average acceleration is calculated, and the average acceleration of each section corresponding to a plurality of time intervals is compared with the overall average acceleration, and the difference between the first section average acceleration and the overall average acceleration among the section average accelerations is an arbitrary acceleration. When the difference is greater than the difference, the time interval corresponding to the average acceleration of the first section is confirmed, the position of the mobile robot is confirmed in the confirmed time interval, and the identified position of the mobile robot is detected as an uneven surface. .

The mobile robot and its non-smooth surface detection method according to an embodiment of the present invention have the effect of recognizing the non-smooth surface by checking the speed change of the mobile robot.

A detailed description of each drawing is provided in order to more fully understand the drawings recited in the Detailed Description of the Invention.
1 is a block diagram of a mobile robot according to an embodiment of the present invention.
2 shows graphs of speed according to time when the mobile robot is traveling at a constant speed.
3 shows graphs of speed according to time when the mobile robot is traveling with acceleration.
4 shows graphs of different speeds according to time when the mobile robot is traveling with acceleration.
5 is a conceptual diagram of a cost map according to an embodiment of the present invention.
6 is a flowchart of a surface sensing method according to an embodiment of the present invention.

Specific structural or functional descriptions for the embodiments according to the concept of the present invention disclosed in this specification are only exemplified for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention are It may be implemented in various forms and is not limited to the embodiments described herein.

Since the embodiments according to the concept of the present invention may have various changes and may have various forms, the embodiments will be illustrated in the drawings and described in detail herein. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosed forms, and includes all modifications, equivalents, or substitutes included in the spirit and scope of the present invention.

Terms such as first or second may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one element from other elements, for example, without departing from the scope of the present invention, a first element may be called a second element, and similarly The second component may also be referred to as the first component.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is mentioned that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle. Other expressions describing the relationship between elements, such as "between" and "immediately between" or "neighboring to" and "directly adjacent to", etc., should be interpreted similarly.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. As used herein, "includes." Or "have." The term etc. is intended to designate that there is a described feature, number, step, action, component, part, or combination thereof, but one or more other features or number, step, action, component, part, or combination thereof. It should be understood that it does not preclude the possibility of the existence or addition of one.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present specification. does not

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings.

1 is a block diagram of a mobile robot according to an embodiment of the present invention.

Referring to FIG. 1 , the mobile robot 10 detects an uneven surface 101 , 103 , or 105 while freely traveling in a space 100 . The space 100 refers to various places such as a house, a factory, a building, or a road. A non-smooth surface 101 , 103 , or 105 may mean a pothole eroded in a roadway.

The mobile robot 10 includes a processor 11 , a memory 13 , an acceleration sensor 12 , a fall arrest sensor 18 , and a wheel 19 . According to an embodiment, the mobile robot 10 may further include a physical bumper 15 or a sonar sensor 17 .

The processor 11 executes instructions for controlling operations of the mobile robot 10 . Specifically, the processor 11 executes instructions for executing the method of detecting an uneven surface of the mobile robot 10 . According to an embodiment, the processor 11 may be referred to by various terms such as a controller. The processor 11 controls the operations of the acceleration sensor 12 , the fall arrest sensor 18 , or the wheel 19 . In this specification, the operations of the mobile robot 10 may be understood as being performed by the processor 11 . Conversely, operations of the processor 11 may be understood as operations of the mobile robot 10 .

The memory 13 stores instructions executed by the processor 11 .

The acceleration sensor 12 measures the acceleration of the mobile robot 10 . The acceleration sensor 12 may be implemented in various positions of the mobile robot 10 .

The mobile robot 10 freely travels on the ground in the space 100 . The fall prevention sensor 17 may recognize a difference in height of the ground.

The wheel 19 is used to move the mobile robot 10 . The number of wheels 19 may vary according to embodiments.

After the mobile robot 10 travels in the space 100 , it is determined whether the mobile robot 10 travels at a constant speed, accelerates, or decelerates. Whether constant speed driving, acceleration driving, or deceleration driving may be determined according to the acceleration measured by the acceleration sensor 12 . For example, if the acceleration measured by the acceleration sensor 12 is 0, it is a constant speed travel, if the acceleration measured by the acceleration sensor 12 is a positive value, it is an acceleration travel, and the acceleration measured by the acceleration sensor 12 If is a negative value, it is decelerated driving.

2 shows graphs of speed according to time when the mobile robot is traveling at a constant speed. Figure 2 (a) is a speed graph showing the real-time speed and section average speed of the mobile robot over time, and Figure 2 (b) shows the average speed and section average speed of the mobile robot over time.

Referring to FIGS. 1 and 2 ( a ), it is assumed that the mobile robot 10 is traveling in the space 100 for an arbitrary time. The arbitrary time may be divided into a plurality of time intervals T1 to T5. The plurality of time intervals T1 to T5 may be arbitrarily set. For example, the plurality of time intervals T1 to T5 may be variously set, such as 1 second or 2 seconds. Also, each of the plurality of time intervals T1 to T5 may be the same.

In FIG. 2A , reference numeral v1 denotes a graph of the real-time speed of the mobile robot 10 for an arbitrary time. In FIG. 2A , reference numeral v2 denotes a graph of section average speeds for each of the plurality of time intervals T1 to T5.

Each of the section average speeds for each of the plurality of time intervals T1 to T5 represents the acceleration measured by the acceleration sensor 12 during each time interval T1 to T5 and the period of each time interval T1 to T5. It is calculated by multiplying

The acceleration measured by the acceleration sensor 12 may mean an acceleration having the greatest value during each time interval T1 to T5 or an acceleration arbitrarily measured during each time interval T1 to T5 .

The period of each time interval T1 to T5 means a time difference between the end time of each time interval T1 ~ T5 and the start time of each time interval T1 ~ T5. For example, the section average speed in the first time interval T1 is calculated by multiplying the acceleration measured by the acceleration sensor 12 during the first time interval T1 by the period t1-t0 of the first time interval T1. do. Similarly, the interval average speed in the second time interval T2 is calculated by multiplying the acceleration measured by the acceleration sensor 12 during the second time interval T2 by the period t2-t1 of the second time interval T2. do.

Assuming that the mobile robot 10 does not pass the uneven surface during the first time interval T1 and the second time interval T2, the section average speed and the In the second time interval T2, the interval average speed may be the same.

The section average speed in the third time interval T3 is calculated by multiplying the acceleration measured by the acceleration sensor 12 during the third time interval T3 by the period t3-t2 of the third time interval T3. The real-time speed of the mobile robot 10 in the third time interval T3 is relatively faster than the real-time speed of the other time intervals (eg, T1, T2, T4, and T5). This is because the speed of the mobile robot 10 is rapidly changed while passing the non-smooth surface 101 , 103 , or 105 . Since the real-time speed of the mobile robot 10 in the third time interval T3 is relatively faster than the real-time speed of the other time intervals (eg, T1, T2, T4, and T5), in the third time interval T3 The interval average speed is relatively faster than the interval average speeds of other time intervals (eg, T1, T2, T4, and T5).

In FIG. 2B , reference numeral v2 denotes a graph of section average speeds for each of the plurality of time intervals T1 to T5. In FIG. 2B , reference numeral v3 denotes a graph of the overall average speed for all of the plurality of time intervals T1 to T5 .

A graph v2 of section average speeds for each of the plurality of time intervals T1 to T5 in (b) of FIG. 2 is a section for each of the plurality of time intervals T1 to T5 in (a) of FIG. Same as graph (v2) of average velocities.

The overall average speed for all of the plurality of time intervals T1 to T5 is obtained by summing the average speeds for each of the plurality of time intervals T1 to T5 and using the summed value for the plurality of time intervals T1 to T5. It is calculated by dividing by the number of If this is expressed as an equation, it is as the following equation.

[Equation 1]

V_avg=(V_[T1]+V_[T2]+V_[T3]+V_[T4]+V_[T5])/5

Here, V_avg is the overall average velocity for all of the plurality of time intervals T1 to T5, and V_[T1], V_[T2], V_[T3], V_[T4], and V_[T5] are the plurality of Section average speeds for each of the time intervals T1 to T5, 5 means the number of the plurality of time intervals T1 to T5. Equation 1 may vary according to the number of the plurality of time intervals T1 to T5.

The mobile robot 10 has section average speeds (V_[T1], V_[T2], V_[T3], V_[T4], and V_[T5]) corresponding to the plurality of time intervals T1 to T5. Compare each with the overall average velocity (V_avg).

A first interval average speed (eg, V_[T3]) of the interval average speeds V_[T1], V_[T2], V_[T3], V_[T4], and V_[T5] and the overall average When the difference in speed V_avg is greater than or equal to a certain speed difference, the mobile robot 10 identifies a first time interval (eg, T3) corresponding to the first interval average speed (eg, V_[T3]).

The mobile robot 10 checks the position of the mobile robot 10 in the identified first time interval (eg, T3), and sets the position of the mobile robot 10 on a non-smooth surface (eg, 101, 103). , or 105).

According to an embodiment, the second section average speed (eg, V_[T4]) among the section average speeds V_[T1], V_[T2], V_[T3], V_[T4], and V_[T5]) When the difference between and the overall average speed V_avg is equal to or greater than the arbitrary speed difference, the mobile robot 10 performs a second time interval (eg, T4) corresponding to the second interval average velocity (eg, V_[T4]). )can confirm. In this case, the first time interval (eg, T3) and the second time interval (eg, T4) are consecutive time intervals. That is, it is assumed that the mobile robot 10 detects an uneven surface (eg, 101, 103, or 105) in the first time interval (eg, T3). Detecting an uneven surface (eg, 101, 103, or 105) in a first time interval (eg, T3), the mobile robot 10 performs a second interval average speed (eg, T4) in a second time interval (eg, T4) , V_[T4]) and a second time interval (eg, T4) in which the difference between the overall average speed V_avg is equal to or greater than the arbitrary speed difference is identified.

The mobile robot 10 may identify a difference between a start time (eg, t2) of the first time interval (eg, T3) and an end time (eg, t4) of the second time interval (eg, T4).

The mobile robot 10 determines that the difference between the start time (eg, t2) of the first time interval (eg, T3) and the end time (eg, t4) of the second time interval (eg, T4) is less than an arbitrary time When the mobile robot 10 starts the first time interval (eg, T3) (eg, t2) and the second time interval (eg, T4) ends (eg, t4) difference (t4) t2) multiplied by the interval average velocity V_[T2] at any of the plurality of time intervals T1 to T5 (eg T2) to multiply the uneven surface (eg 101, 103, or 105) ) can be calculated. The mobile robot 10 determines that the difference between the start time (eg, t2) of the first time interval (eg, T3) and the end time (eg, t4) of the second time interval (eg, T4) is less than an arbitrary time When the first time interval (eg, T3) detects a non-smooth surface (eg, 101, 103, or 105) and the second time interval (eg, T4) detects a non-smooth surface (eg, 101, 103, or 105) may be perceived as a single non-smooth surface (eg, 101, 103, or 105).

In order to calculate the size of the uneven surface (eg, 101, 103, or 105), a section average speed V_[T2] when the mobile robot 10 travels at a constant speed is used. When the mobile robot 10 does not travel at a constant speed on a non-smooth surface (eg, 101, 103, or 105), that is, when moving on an uneven surface (eg, 101, 103, or 105), the mobile robot 10 ) is faster than when traveling at a constant speed, so it can be calculated to be larger than the size of an actual non-smooth surface (eg, 101, 103, or 105).

In the mobile robot 10, the difference between the start time (eg, t2) of the first time interval (eg, T3) and the end time (eg, t4) of the second time interval (eg, T4) is more than an arbitrary time When the mobile robot 10 detects a non-smooth surface (eg, 101, 103, or 105) in the first time interval (eg, T3) and the non-smooth surface detected in the second time interval (eg, T4) Surfaces (eg, 101 , 103 , or 105 ) are recognized as different non-smooth surfaces. Accordingly, the mobile robot 10 determines the difference (t3-t2) between the start time (eg, t2) of the first time interval (eg, T3) and the end time (eg, t3) of the first time interval (eg, T3) and , the size of the uneven surface (eg, 101, 103, or 105) multiplied by the interval average velocity (V_[T2]) at any time interval (eg, T2) among the plurality of time intervals (T1 to T5) can be calculated. In addition, the mobile robot 10 has a difference (t4-t3) between the start time (eg, t3) of the second time interval (eg, T4) and the end time (eg, t4) of the second time interval (eg, T4) and multiplied by the interval average velocity V_[T2] at any time interval (eg, T2) among the plurality of time intervals T1 to T5 of the uneven surface (eg, 101, 103, or 105). size can be calculated.

According to an embodiment, the mobile robot 10 may further include an angular velocity sensor (not shown).

The mobile robot 10 detects changes in the X-axis direction and the Y-axis direction of the angular velocity sensor included in the mobile robot 10 while the mobile robot 10 is traveling.

When the amount of change in the X-axis direction of the angular velocity sensor is greater than or equal to a certain amount of change, and the amount of change in the Y-axis direction of the angular velocity sensor is greater than or equal to the predetermined amount of change, the mobile robot 10 has a non-smooth surface (eg, 101). , 103, or 105). Therefore, in the mobile robot 10, when the amount of change in the X-axis direction of the angular velocity sensor is greater than or equal to a certain amount of change, and the amount of change in the Y-axis direction of the angular velocity sensor is greater than or equal to the above-mentioned arbitrary amount of change, the method of detecting an uneven surface of the mobile robot 10 is is carried out This is simply to distinguish it from the change in inertia caused by the rotation of the mobile robot 10 . In the case of the mobile robot 10, when the amount of change in the X-axis direction of the angular velocity sensor is greater than or equal to a certain amount of change, and the amount of change in the Y-axis direction of the angular velocity sensor is less than the arbitrary amount of change, it is simply the inertia caused by the rotation of the mobile robot 10. considered a change. In addition, in the mobile robot 10, when the amount of change in the X-axis direction of the angular velocity sensor is less than the arbitrary change amount, and the change amount in the Y-axis direction of the angular velocity sensor is greater than the arbitrary change amount, it is simply according to the rotation of the mobile robot 10 It is considered as a change in inertia.

That is, in the mobile robot 10, when the amount of change in the X-axis direction of the angular velocity sensor is greater than or equal to an arbitrary amount of change, and the amount of change in the Y-axis direction of the angular velocity sensor is greater than or equal to the arbitrary change amount, the mobile robot 10 operates in the space 100. It is determined whether the traveling of the mobile robot 10 is constant speed traveling, acceleration traveling, or deceleration traveling, and an uneven surface (eg, 101 , 103 , or 105 ) is sensed according to the type of traveling.

3 shows graphs of speed according to time when the mobile robot is traveling with acceleration. Fig. 3 (a) is a speed graph showing the speed of the mobile robot over time when the mobile robot is traveling at a deceleration, and Fig. 3 (b) is the average acceleration and section average acceleration of the mobile robot over time. indicates.

Referring to FIGS. 1 and 3 (a) , the mobile robot 10 decelerates according to time. Reference numeral v4 in FIG. 3A denotes a graph of the speed of the mobile robot 10 for an arbitrary time.

Reference numeral v5 in FIG. 3B denotes a graph of section average accelerations for each of the plurality of time intervals T1 to T5. In FIG. 3B , reference numeral v6 denotes a graph of the overall average acceleration for all of the plurality of time intervals T1 to T5 .

Each of the section average accelerations for each of the plurality of time intervals T1 to T5 is an acceleration measured by the acceleration sensor 12 during each time interval T1 to T5. For example, the section average acceleration in the first time interval T1 is the acceleration measured by the acceleration sensor 12 during the first time interval T1 . Similarly, the interval average acceleration in the second time interval T2 is the acceleration measured by the acceleration sensor 12 during the second time interval T2 . Since the mobile robot 10 travels in deceleration, the acceleration measured by the acceleration sensor 12 should be negative, but may be positive due to an error of the acceleration sensor 12 .

The overall average acceleration for all of the plurality of time intervals T1 to T5 is obtained by summing the section average accelerations for each of the plurality of time intervals T1 to T5 and adding the summed value to the plurality of time intervals ( It is calculated by dividing by the number of T1 to T5). If this is expressed as an equation, it is as the following equation.

[Equation 2]

A_avg=(A_[T1]+A_[T2]+A_[T3]+A_[T4]+A_[T5])/5

Here, A_avg is the overall average acceleration for all of the plurality of time intervals T1 to T5, A_[T1], A_[T2], A_[T3], A_[T4], and A_[T5] are the plurality of The interval average accelerations for each of the time intervals T1 to T5, 5 denotes the number of the plurality of time intervals T1 to T5. Equation 2 may vary depending on the number of the plurality of time intervals T1 to T5.

The mobile robot 10 has section average accelerations corresponding to the plurality of time intervals T1 to T5 (A_[T1], A_[T2], A_[T3], A_[T4], and A_[T5]). Compare each with the overall average acceleration A_avg.

The first interval average acceleration (eg, A_[T3]) and the overall average among the interval average accelerations A_[T1], A_[T2], A_[T3], A_[T4], and A_[T5]) The difference in acceleration A_avg is less than or equal to any acceleration difference. The overall average acceleration (A_avg) has a constant value and is negative.

4 shows graphs of different speeds according to time when the mobile robot is traveling with acceleration. Fig. 4 (a) is a speed graph showing the speed of the mobile robot over time when the mobile robot is traveling at a deceleration, and Fig. 4 (b) is the average acceleration and section average acceleration of the mobile robot over time. indicates.

Referring to FIGS. 1 and 4 ( a ), the mobile robot 10 decelerates according to time. However, the difference from Fig. 3 (a) is that in Fig. 4 (a), the mobile robot 10 travels at a deceleration, but passes the non-smooth surface 101, 103, or 105 at the third time interval T3. . Therefore, referring to (a) of FIG. 4 , the speed suddenly increases in the third time interval T3 , unlike in FIG. 3 (a).

Reference numeral v7 in FIG. 4A denotes a graph of the speed of the mobile robot 10 for an arbitrary time.

In FIG. 4B , reference numeral v8 denotes a graph of section average accelerations for each of the plurality of time intervals T1 to T5 . In FIG. 4B , reference numeral v9 denotes a graph of the overall average acceleration for all of the plurality of time intervals T1 to T5 .

Referring to FIGS. 1 and 4 (b) , section average accelerations A_[T1], A_[T2], A_[T3], A_[T4] for each of the plurality of time intervals T1 to T5 , and A_[T5]) each is an acceleration measured by the acceleration sensor 12 during each time interval T1 to T5.

The total average acceleration A_avg for all of the plurality of time intervals T1 to T5 is obtained by summing the average accelerations for each of the plurality of time intervals T1 to T5 and using the summed value for the plurality of time intervals T1 It is calculated by dividing by the number of ∼T5). That is, it is calculated as in Equation 2 above.

The mobile robot 10 has section average accelerations corresponding to the plurality of time intervals T1 to T5 (A_[T1], A_[T2], A_[T3], A_[T4], and A_[T5]) Compare each with the overall average acceleration A_avg.

The first interval average acceleration (eg, A_[T3]) and the overall average among the interval average accelerations A_[T1], A_[T2], A_[T3], A_[T4], and A_[T5]) When the difference between the accelerations A_avg is greater than or equal to a certain acceleration difference, the mobile robot 10 checks a time interval (eg, T3 ) corresponding to the average acceleration of the first section.

The mobile robot 10 checks the position of the mobile robot 10 at the confirmed time interval (eg, T3), and detects the confirmed position of the mobile robot 10 as an uneven surface.

5 is a conceptual diagram of a cost map according to an embodiment of the present invention.

1 to 5 , the cost map 50 is divided into a plurality of grids. Each grid contains information about cost.

The mobile robot 10 may further include a lidar sensor 14 . The mobile robot 10 may determine whether there are obstacles 20 or 30 around the mobile robot 10 using the lidar sensor 14 . The obstacle 20 or 30 refers to an object through which the mobile robot 10 cannot pass. The periphery of the mobile robot 10 refers to the front, rear, or side of the mobile robot 10 . According to an embodiment, the lidar sensor 14 emits a laser at the same time from the front, rear, and side of the mobile robot 10 , and moves by measuring the time it takes for the reflected light to return to the lidar sensor 14 . The robot 10 may determine the position of the obstacle 20 or 30 at the same time in the front, rear, and side of the mobile robot 10 .

When the mobile robot 10 determines that there is an obstacle 20 or 30 around the mobile robot 10 , the mobile robot 10 moves to a location corresponding to the obstacle 20 or 30 on the cost map 50 . Set an arbitrary first value (eg, 254) as cost in the grid of .

The mobile robot 10 sets an arbitrary second value (eg, 127) as the cost in the grid of obstacle-free positions in the cost map 50 . The cost ranges from zero to a first value (eg, 254).

The mobile robot 10 increases the cost depending on the number of detections of an uneven surface (eg, 101 , 103 , or 105 ). The mobile robot 10 can freely travel in the space 100 and accumulate and detect the uneven surfaces 101 , 103 , or 105 .

The increased cost may increase to any second value (eg, 127). That is, any grating corresponding to a non-smooth surface (eg, 101 , 103 , or 105 ) ranges from 0 to an arbitrary second value (eg, 127 ). According to an embodiment, the cost may be expressed in color in the cost map 50 .

The mobile robot 10 can drive by avoiding an uneven surface (eg, 101, 103, or 105) and an obstacle (20, or 30) by moving to a path having the lowest cost when traveling in a specific space 100 later. have.

6 is a flowchart of a surface sensing method according to an embodiment of the present invention.

1 and 2 , after the mobile robot 10 travels in the space 100 , it is determined whether the mobile robot 10 travels at a constant speed, accelerates, or decelerates ( S10 ).

When the mobile robot 10 travels at a constant speed, the mobile robot 10 calculates an overall average speed V_avg during the running time of the mobile robot 10 ( S20 ).

The mobile robot 10 has section average speeds (V_[T1], V_[T2], V_[T3], V_[T4], and V_[T5]) corresponding to the plurality of time intervals T1 to T5. The angle and the overall average velocity V_avg are compared (S30). The overall average speed for all of the plurality of time intervals T1 to T5 is obtained by summing the average speeds for each of the plurality of time intervals T1 to T5 and using the summed value for the plurality of time intervals T1 to T5. It is calculated by dividing by the number of

A first interval average speed (eg, V_[T3]) of the interval average speeds V_[T1], V_[T2], V_[T3], V_[T4], and V_[T5] and the overall average When the difference in speed V_avg is greater than or equal to a certain speed difference, the mobile robot 10 checks the first time interval (eg, T3) corresponding to the first section average speed (eg, V_[T3]) ( S40).

The mobile robot 10 checks the position of the mobile robot 10 in the identified first time interval (eg, T3), and sets the position of the mobile robot 10 on a non-smooth surface (eg, 101, 103). , or 105) (S50).

1 and 4 , the traveling of the mobile robot 10 is accelerated driving. Alternatively, during deceleration, the mobile robot 10 calculates the overall average acceleration A_avg during the running time of the mobile robot 10 ( S60 ). The overall average acceleration for all of the plurality of time intervals T1 to T5 is obtained by summing the section average accelerations for each of the plurality of time intervals T1 to T5 and adding the summed value to the plurality of time intervals ( It is calculated by dividing by the number of T1 to T5).

The mobile robot 10 has section average accelerations corresponding to the plurality of time intervals T1 to T5 (A_[T1], A_[T2], A_[T3], A_[T4], and A_[T5]) Each is compared with the overall average acceleration A_avg (S70).

The first interval average acceleration (eg, A_[T3]) and the overall average among the interval average accelerations A_[T1], A_[T2], A_[T3], A_[T4], and A_[T5]) When the difference between the accelerations A_avg is greater than or equal to a certain acceleration difference, the mobile robot 10 checks a time interval (eg, T3) corresponding to the first interval average acceleration (S80).

The mobile robot 10 checks the position of the mobile robot 10 at the confirmed time interval (eg, T3), and detects the confirmed position of the mobile robot 10 as a non-smooth surface (S90).

According to an embodiment, the mobile robot 10 may further include an angular velocity sensor (not shown). Sensor values for the X-axis, Y-axis, and Z-axis are generated by the angular velocity sensor.

Sensor values generated by the angular velocity sensor when the mobile robot 10 passes an uneven surface (eg 101, 103, or 105), and a sensor generated by the angular velocity sensor when the mobile robot 10 rotates. The values are different. When the mobile robot 10 rotates, only one of the X-axis sensor value and the Y-axis sensor value generated by the angular velocity sensor will be greater than the threshold value. This is because only one of the X-axis sensor value and the Y-axis sensor value changes as the mobile robot 10 moves left or right. On the other hand, when the mobile robot 10 passes over a non-smooth surface (eg, 101, 103, or 105), both the X-axis sensor value and the Y-axis sensor value generated by the angular velocity sensor will be greater than the threshold value.

Accordingly, the mobile robot 10 receives the X-axis sensor value and the Y-axis sensor value from the angular velocity sensor. The mobile robot 10 determines whether each of the received X-axis sensor values and Y-axis sensor values is greater than an arbitrary threshold value. When each of the received X-axis sensor values and Y-axis sensor values is greater than the arbitrary threshold value, the mobile robot 10 determines that the mobile robot 10 is tilted. The arbitrary threshold value may be an average angular velocity during the traveling time of the mobile robot 10 . The average angular velocity may be an average angular velocity with respect to an X-axis sensor value and an average angular velocity with respect to a Y-axis sensor value.

When it is determined that the mobile robot 10 is tilted, that is, when the received X-axis sensor value and the Y-axis sensor value are both greater than a certain threshold, the mobile robot 10 is not smooth. A surface sensing method according to an embodiment of the present invention is performed to detect an unfavorable surface (eg, 101 , 103 , or 105 ). That is, operations S10 to S90 are performed.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those of ordinary skill in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

10: mobile robot;
11: processor;
12: acceleration sensor;
13: memory;
15: physical bumper;
17: sonar sensor;
18: fall arrest sensor;
19: wheel;

Claims (6)

when the mobile robot determines that the mobile robot is traveling at a constant speed, calculating, by the mobile robot, an overall average speed during the running time of the mobile robot;
comparing, by the mobile robot, each of the section average speeds corresponding to a plurality of time intervals and the overall average speed;
checking, by the mobile robot, a first time interval corresponding to the first section average speed when a difference between the first section average speed and the overall average speed among the section average speeds is greater than or equal to a certain speed difference; and
and detecting, by the mobile robot, the position of the mobile robot at the identified first time interval, and detecting the identified position of the mobile robot as a non-smooth surface. The method according to claim 1, wherein the method for detecting an uneven surface of the mobile robot comprises:
checking, by the mobile robot, a second time interval corresponding to the second section average speed when the difference between the second section average speed and the overall average speed among the section average speeds is equal to or greater than the arbitrary speed difference;
checking, by the mobile robot, a difference between a start time of the first time interval and an end time of the second time interval; and
When the difference between the start time of the first time interval and the end time of the second time interval is less than a predetermined time, the mobile robot determines the start time of the first time interval and the end of the second time interval. calculating the size of the uneven surface by multiplying the time difference by the interval average velocity at any of the plurality of time intervals;
wherein the first time interval and the second time interval are consecutive time intervals. The method according to claim 2, wherein the section average speed at any time interval among the plurality of time intervals is the section average speed when the mobile robot travels at a constant speed. calculating, by the mobile robot, an overall average acceleration during the traveling time of the mobile robot when the mobile robot determines that the traveling of the mobile robot is accelerated driving;
comparing, by the mobile robot, each of the section average accelerations corresponding to a plurality of time intervals and the overall average acceleration;
checking, by the mobile robot, a time interval corresponding to the first section average acceleration when the difference between the first section average acceleration and the overall average acceleration among the section average accelerations is equal to or greater than a certain acceleration difference; and
and detecting, by the mobile robot, the position of the mobile robot at the identified time interval, and detecting the identified position of the mobile robot as a non-smooth surface. In the mobile robot,
accelerometer;
a processor executing instructions for controlling operations of the mobile robot; and
a memory for storing the instructions;
The commands are
When it is determined that the traveling of the mobile robot is traveling at a constant speed, calculating the overall average speed during the traveling time of the mobile robot,
comparing each of the section average speeds corresponding to a plurality of time intervals with the overall average speed,
When the difference between the first section average speed and the overall average speed among the section average speeds is greater than or equal to an arbitrary speed difference, a first time interval corresponding to the first section average speed is checked,
The mobile robot is implemented to confirm the position of the mobile robot in the confirmed first time interval, and to detect the identified position of the mobile robot as a non-smooth surface. In the mobile robot,
accelerometer;
a processor executing instructions for controlling operations of the mobile robot; and
a memory for storing the instructions;
The commands are
When it is determined that the driving of the mobile robot is accelerated driving, the mobile robot calculates an overall average acceleration during the driving time of the mobile robot,
comparing each of the section average accelerations corresponding to a plurality of time intervals with the overall average acceleration;
When the difference between the first section average acceleration and the overall average acceleration among the section average accelerations is equal to or greater than an arbitrary acceleration difference, a time interval corresponding to the first section average acceleration is checked;
The mobile robot is implemented to confirm the position of the mobile robot in the confirmed time interval, and to detect the identified position of the mobile robot as a non-smooth surface.

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