WO2022097929A1

WO2022097929A1 - Robot and control method therefor

Info

Publication number: WO2022097929A1
Application number: PCT/KR2021/013493
Authority: WO
Inventors: 유선겸; 김준영
Original assignee: 삼성전자주식회사
Priority date: 2020-11-06
Filing date: 2021-10-01
Publication date: 2022-05-12

Abstract

A robot is disclosed. The robot according to the present disclosure comprises a manipulator, memory, and a processor, wherein the processor acquires a first signal relating to an external force acting on the manipulator, acquires a second signal from which a low-frequency component of the first signal has been removed, and a third signal from which a high-frequency component of the first signal has been removed, and compares the size of the second signal and the size of the third signal to a preset value to determine whether there is a collision between the robot and an obstacle.

Description

Robot and its control method

The present disclosure relates to a robot and a control method thereof, and more particularly, to a robot detecting a collision with an obstacle and a control method thereof.

In recent years, with the development of robot technology, various types of robots such as cleaning robots, service robots, and industrial robots are being used. As an example of the industrial robot, there is a manipulator in the form of a human hand and arm to provide a motion of the hand and arm. Manipulators are being actively used for collaborative work between robots and robots or between robots and humans.

On the other hand, a manipulator that performs collaborative work with humans is highly likely to collide with humans due to its characteristics. Therefore, for the safety of manipulators and people, research on a method for accurately detecting a collision is required. As a conventional collision detection method, there is a method of detecting a collision using a sensor or an observer, but according to this method, a separate sensor is required, and there is a problem that the accuracy of the sensor is lowered according to the physical properties of the robot.

Accordingly, there is a need for a technology capable of accurately detecting a collision between a robot and a person (or an obstacle).

One technical problem to be solved by the present invention is to provide a robot capable of acquiring an external force acting on a manipulator without an external force measuring sensor.

Another technical problem to be solved by the present invention is to provide a robot capable of accurately detecting a collision with an obstacle.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to an exemplary embodiment of the present disclosure for solving the above-described technical problem, in a robot, a manipulator (manipulator) including a joint and a link connected to the joint; a memory storing at least one instruction; and a processor, wherein the processor obtains a first signal for an external force acting on the manipulator, a second signal from which a low-frequency component of the first signal is removed, and a third signal from which a high-frequency component of the first signal is removed. A robot may be provided that acquires a signal and determines whether the robot collides with an obstacle by comparing the magnitude of the second signal and the magnitude of the third signal with a preset value.

The processor, if there is a time period in which the magnitude of the third signal is greater than the preset value within a preset time range from the first time point when the magnitude of the second signal starts to become greater than the preset value, the robot and It may be determined that the obstacle collides.

The processor may determine that the robot and the obstacle do not collide when there is no time interval in which the magnitude of the third signal is greater than the preset value.

The robot further includes a communication interface, wherein the processor obtains a user command for setting at least one of the preset value and the preset time range from an external device through the communication interface, and responds to the user command. Based on the update, at least one of the preset value and the preset time range may be updated and stored in the memory.

The robot may further include a motor for providing power to the joint, and the processor may obtain the first signal based on location information of the link, speed information of the link, and location information of the motor. there is.

The processor may input the first signal to a high-pass filter to obtain the second signal, and input the first signal to a low-pass filter to obtain the third signal.

The preset time range may be determined based on a cutoff frequency for the first signal.

When it is determined that the robot and the obstacle collide, the processor may stop the operation of the manipulator and generate a travel route for avoiding the obstacle.

According to another exemplary embodiment of the present disclosure for solving the above-described technical problem, in a control method of a robot including a manipulator including a joint and a link connected to the joint, the manipulator acts on the obtaining a first signal for an external force; obtaining a second signal from which a low frequency component of the first signal is removed and a third signal from which a high frequency component of the first signal is removed; and determining whether the robot collides with an obstacle by comparing the magnitude of the second signal and the magnitude of the third signal with a preset value.

In the determining step, if there is a time interval in which the magnitude of the third signal is greater than the preset value within a preset time range from the first time point when the magnitude of the second signal starts to become greater than the preset value, the It may be determined that the robot collides with the obstacle.

The determining may include determining that the robot and the obstacle do not collide when there is no time period in which the third signal is greater than the preset value.

The control method may include: obtaining a user command for setting at least one of the preset value and the preset time range from an external device; and updating and storing at least one of the preset value and the preset time range based on the user command.

The obtaining of the first signal may include obtaining the first signal based on location information of the link, speed information of the link, and location information of a motor for providing power to the joint.

The obtaining of the second signal may include inputting the first signal to a high-pass filter to obtain the second signal, and the obtaining of the third signal may include inputting the first signal to a low-pass filter to obtain the third signal. The third signal may be obtained.

The control method may further include, when it is determined that the robot collides with the obstacle, stopping the operation of the manipulator and generating a travel route for avoiding the obstacle.

The solutions to the problems of the present disclosure are not limited to the above-described solutions, and solutions not mentioned will be clearly understood by those of ordinary skill in the art to which the present disclosure belongs from the present specification and the accompanying drawings. will be able

According to various embodiments of the present disclosure as described above, the robot may acquire an external force acting on the manipulator without an external force measuring sensor. In addition, the robot can accurately detect a collision with an obstacle. Accordingly, the safety of the robot can be improved.

In addition, the effects obtainable or predicted by the embodiments of the present disclosure are to be disclosed directly or implicitly in the detailed description of the embodiments of the present disclosure. For example, various effects predicted according to embodiments of the present disclosure will be disclosed in the detailed description to be described later.

1 is a diagram illustrating a robot according to an embodiment of the present disclosure.

2 is a block diagram illustrating a configuration of a robot according to an embodiment of the present disclosure.

3 is a flowchart illustrating a method for controlling a robot according to an embodiment of the present disclosure.

4 is a view for explaining a collision detection method according to an embodiment of the present disclosure.

5 is a diagram illustrating an external device according to an embodiment of the present disclosure.

6 is a view for explaining a state transition of a robot according to an embodiment of the present disclosure.

Terms used in this specification will be briefly described, and the present disclosure will be described in detail.

Terms used in the embodiments of the present disclosure are selected as currently widely used general terms as possible while considering the functions in the present disclosure, which may vary depending on the intention or precedent of a person skilled in the art, the emergence of new technology, etc. . In addition, in a specific case, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the corresponding disclosure. Therefore, the terms used in the present disclosure should be defined based on the meaning of the term and the contents of the present disclosure, rather than the simple name of the term.

Embodiments of the present disclosure may be subjected to various transformations and may have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the scope of the specific embodiments, and it should be understood to include all transformations, equivalents and substitutions included in the spirit and scope of the disclosure. In describing the embodiments, if it is determined that a detailed description of a related known technology may obscure the subject matter, the detailed description thereof will be omitted.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "comprises" or "consisting of" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but one or more other It should be understood that this does not preclude the possibility of addition or presence of features or numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present disclosure pertains can easily implement them. However, the present disclosure may be implemented in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present disclosure in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

The robot 100 may include a manipulator 110 and a driving unit 120 . The manipulator 110 may include a joint 111 corresponding to a joint of the manipulator 110 and a plurality of links 112 connected to the joint 111 . For example, the plurality of links 112 may include first links 112-1 and 112-2. The driving unit 120 may include wheels for moving the robot 100 .

The robot 100 may perform an operation for collaboration with other robots or people. For example, the robot 100 may transmit an object to another robot or a person using the manipulator 110 . As such, while the robot 100 is operating, a collision between the robot 100 and an obstacle may occur. In the present disclosure, the obstacle may include an object other than the robot 100 . For example, the obstacle may include various objects existing in the space in which the robot 100 is located, including other robots and people.

The robot 100 may acquire an external force acting on the manipulator and detect a collision with an obstacle based on the acquired external force. Accordingly, the safety of the robot 100 may be improved.

2 is a block diagram illustrating a configuration of a robot according to an embodiment of the present disclosure. The robot 100 may include a manipulator 110 , a driving unit 120 , a sensor unit 130 , a driving unit 140 , a communication interface 150 , a memory 160 , and a processor 170 .

The manipulator 110 may perform an operation necessary for the robot 100 to perform a task under the control of the processor 170 . For example, the manipulator 110 may grip the object and then move it to a specific position. The manipulator 110 may include a joint and a link connected to the joint. Also, the manipulator 110 may include a hand for gripping the object.

The driving unit 120 may include a wheel for moving the robot 100 and a wheel driving motor for rotating the wheel. In addition, the driving unit 120 includes a motor driving circuit for supplying a driving current to the wheel driving motor, a power transmission module for transmitting the rotational force of the wheel driving motor to the wheels, and a wheel driving motor or for detecting the rotational displacement and rotational speed of the wheel. It may further include a rotation detection sensor.

The sensor unit 130 may include an encoder for acquiring positions and speeds of joints and links included in the manipulator 110 . In addition, the encoder may sense the position and rotation speed of a motor for driving the joint. In addition, the sensor unit 130 may include various sensors for collecting information necessary for the driving of the robot 100 . For example, the sensor unit 130 may include a lidar sensor, a depth sensor, a camera, and a motion sensor. However, the present invention is not limited thereto, and the sensor unit 130 may further include various sensors such as an ultrasonic sensor.

The driving unit 140 may include an actuator that provides power to the manipulator 110 . For example, an actuator may provide power to a joint. The actuator may include various types of motors, such as linear motors, AC sub-motors, step motors, and the like.

The communication interface 150 includes at least one circuit and may communicate with various types of external devices according to various types of communication methods. The communication interface 150 may receive a user command for setting parameters of the robot 100 from an external device. The external device may include a user terminal and a PC. The parameter of the robot 100 may include a preset torque value for detecting a collision with an obstacle, and a cutoff frequency of a filter for filtering a signal for an external force acting on the robot 100 .

The communication interface 150 is a Wi-Fi module, a Bluetooth module, a ZigBee module, a Beacon module, a cellular communication module, a 3G (3rd generation) mobile communication module, and a 4G (4th generation) mobile communication module. , may include at least one of a 4G Long Term Evolution (LTE) communication module and a 5G (5th Generation) mobile communication module.

The memory 160 may store an operating system (OS) for controlling overall operations of the components of the robot 100 and commands or data related to components of the robot 100 . For example, the memory 160 may store parameters of the robot 100 . The parameter of the robot 100 may include a preset torque value for detecting a collision with an obstacle, and a cutoff frequency of a filter for filtering a signal for an external force acting on the robot 100 . Meanwhile, the memory 160 may be implemented as a non-volatile memory (eg, a hard disk, a solid state drive (SSD), a flash memory), a volatile memory, or the like.

The processor 170 may be electrically connected to the memory 160 to control overall functions and operations of the electronic device 100 . The processor 170 may obtain a first signal for an external force acting on the manipulator. For example, the processor 170 may acquire the first signal based on location information of the link, speed information of the link, and location information of a motor for providing power to the joint.

Also, the processor 170 may obtain a second signal from which a low frequency component of the first signal is removed and a third signal from which a high frequency component of the first signal is removed. The processor 170 may obtain the second signal by inputting the first signal to the high-pass filter. The processor 170 may obtain the third signal by inputting the first signal to the low-pass filter.

Meanwhile, the processor 170 may determine whether the robot 100 collides with the obstacle by comparing the magnitude of the second signal and the magnitude of the third signal with a preset value. For example, if there is a time period in which the magnitude of the third signal is greater than the preset value within a preset time range from the first time point when the magnitude of the second signal starts to become greater than the preset value, the processor 170 is the robot 100 and obstacles may have collided. On the other hand, if there is no time period in which the magnitude of the third signal is greater than the preset value, the processor 170 may determine that the robot 100 and the obstacle do not collide.

The processor 170 may obtain a user command for setting at least one of a preset value and a preset time range from an external device through the communication interface 150 . The processor 170 may update and store at least one of a preset value and a preset time range in the memory 160 based on a user command.

If it is determined that the robot 100 and the obstacle collide, the processor 170 may stop the operation of the manipulator 110 . In addition, the processor 170 may generate a driving path for avoiding the obstacle and control the driving unit 120 to run while avoiding the obstacle.

Meanwhile, although the manipulator 110 has been described as a component of the robot 100 in FIG. 2 , this is only an exemplary embodiment and the robot 100 according to the present disclosure may be implemented as the manipulator 110 . In this case, the manipulator 110 may include a sensor unit 130 , a driving unit 140 , a communication interface 150 , a memory 160 , and a processor 170 .

The robot 100 may acquire a first signal for an external force acting on the manipulator 110 ( S310 ). The robot 100 may obtain the first signal based on the position information of the link, the speed information of the link, and the position information of the motor for providing power to the joint. For example, the robot 100 has an external force (

) to obtain a first signal.

here,

is the link position (link position,),

is the speed of the link,

is the motor position,

is position-dependent link inertia,

is the Coriolis-Centrifugal effect and gravity force,

is the stiffness of the joint,

is a reduction ratio.

Existing robots measure the external force acting on the manipulator by using an external force measuring sensor such as a torque sensor. In contrast, the robot 100 according to the present disclosure may acquire the first signal based on [Equation 1] without an external force measuring sensor.

The robot 100 may obtain a second signal from which the low-frequency component of the first signal is removed and a third signal from which the high-frequency component of the first signal is removed ( S320 ). For example, as shown in FIG. 4 , the robot 100 may obtain the second signal 42 by inputting the first signal 41 to a high pass filter (HPF) 44 . Also, the robot 100 may obtain the third signal 43 by inputting the first signal 41 to the low pass filter (LPF) 45 .

The robot 100 may determine whether the magnitude of the second signal is greater than a preset value (S330). When the magnitude of the second signal is smaller than a preset value, the robot 100 may determine that it does not collide with an obstacle (S360). If the magnitude of the second signal is greater than the preset value, the robot 100 may determine whether the magnitude of the third signal is greater than the preset value (S340). Specifically, the robot 100 can determine whether there is a time period in which the magnitude of the third signal is greater than the preset value within a preset time range from the first time point when the magnitude of the second signal starts to become greater than the preset value. there is. When the magnitude of the third signal is smaller than a preset value, the robot 100 may determine that it does not collide with an obstacle (S360).

On the other hand, if the magnitude of the third signal is greater than a preset value, the robot 100 may determine that it collides with an obstacle (S350). At this time, the robot 100 may stop the operation of the manipulator 110 and generate a travel path for avoiding the obstacle. The second signal may include noise, and accordingly, a value greater than a preset value may be detected. The robot 100 may prevent erroneous collision detection due to noise by determining whether the magnitude of the third signal as well as the magnitude of the second signal is greater than a preset value.

4 is a view for explaining a collision detection method according to an embodiment of the present disclosure. The robot 100 may obtain the second signal 42 by inputting the first signal 41 to the high-pass filter 44 . Also, the robot 100 may obtain the third signal 43 by inputting the first signal 41 to the low-pass filter 45 . The robot 100 sets the size of the second signal 42 to a preset value (

), the magnitude of the third signal 43 is set to a preset value (

), it can be determined that a collision with an obstacle exists. On the other hand, the magnitude of the second signal 42 is a preset value (

), even if it is greater than the preset value (

), the magnitude of the third signal 43 is set to a preset value (

), if there is no time interval larger than ), it can be determined that there is no collision with the obstacle. Meanwhile, the preset time range Td may be a time constant of the robot 100 . The preset time range Td may be determined based on a cutoff frequency (or cutoff frequency of a filter) for the first signal.

5 is a diagram illustrating an external device according to an embodiment of the present disclosure. The external device 200 may be connected to the robot 100 to provide a UI for setting parameter values of the robot 100 . For example, the external device 200 may set a preset value (

) and a second UI element 52 for setting the preset time range Td may be displayed. The external device 200 has a preset value (

) and a user command for setting the preset time range Td may be obtained. The external device 200 may transmit a user command, a parameter value corresponding to the user command, or a control signal for updating the parameter value to the robot 100 . For example, the robot 100 may set a preset value (

) and the preset time range Td may be updated and stored in the memory 160 .

6 is a view for explaining a state transition of a robot according to an embodiment of the present disclosure. The robot 100 has a first state 61 in which it is determined that a collision with an obstacle does not occur, a second state 62 in which a collision with an obstacle is suspected to have occurred, or a third state in which it is determined that a collision with an obstacle has occurred. It can operate in state 63 .

In the first state 61, the robot 100 may determine whether the third signal is greater than a preset value. If the third signal is greater than the preset value, the robot 100 may enter the third state 63 (S61). That is, the robot 100 may determine that the collision with the obstacle has occurred. Also, in the first state 61 , the robot 100 may determine whether the second signal is greater than a preset value. If the second signal is greater than the preset value, the robot 100 may enter the second state 62 (S62).

In the second state 62 , the robot 100 may determine whether the third signal is greater than a preset value. If the third signal is greater than the preset value, the robot 100 may enter the third state 63 (S63). That is, the robot 100 may determine that the collision with the obstacle has occurred. On the other hand, if the third signal is smaller than the preset value, the robot 100 may enter the first state 61 ( S64 ).

In the third state 63 , the robot 100 may determine whether the third signal is smaller than a preset value. When the third signal is smaller than the preset value, the robot 100 may enter the first state 61 (S65).

Meanwhile, the various embodiments described above may be implemented in a recording medium readable by a computer or a similar device using software, hardware, or a combination thereof. In some cases, the embodiments described herein may be implemented by the processor itself. According to the software implementation, embodiments such as procedures and functions described in this specification may be implemented as separate software modules. Each of the software modules may perform one or more functions and operations described herein.

Meanwhile, computer instructions for performing the processing operation according to various embodiments of the present disclosure described above may be stored in a non-transitory computer-readable medium. When the computer instructions stored in the non-transitory computer-readable medium are executed by the processor, the processing operation according to the above-described various embodiments may be performed by a specific device.

The non-transitory computer-readable medium refers to a medium that stores data semi-permanently, not a medium that stores data for a short moment, such as a register, cache, memory, etc., and can be read by a device. Specific examples of the non-transitory computer-readable medium may include a CD, DVD, hard disk, Blu-ray disk, USB, memory card, ROM, and the like.

In the above, preferred embodiments of the present disclosure have been illustrated and described, but the present disclosure is not limited to the specific embodiments described above, and is generally used in the technical field belonging to the present disclosure without departing from the gist of the present disclosure as claimed in the claims. Various modifications can be made by those having the knowledge of

Claims

In the robot,

a manipulator comprising a joint and a link connected to the joint;

a memory storing at least one instruction; and

processor; including;

The processor is

obtaining a first signal for an external force acting on the manipulator;

obtaining a second signal from which the low-frequency component of the first signal is removed and a third signal from which the high-frequency component of the first signal is removed;

determining whether the robot collides with an obstacle by comparing the magnitude of the second signal and the magnitude of the third signal with a preset value

robot.
According to claim 1,

The processor is

When a time period in which the magnitude of the third signal is greater than the preset value exists within a preset time range from the first time point when the magnitude of the second signal starts to become greater than the preset value, the robot and the obstacle collide judged to have

robot.
According to claim 1,

The processor is

If there is no time period in which the magnitude of the third signal is greater than the preset value, it is determined that the robot and the obstacle do not collide.

robot.
3. The method of claim 2,

Communication interface; further comprising,

The processor is

obtaining a user command for setting at least one of the preset value and the preset time range from an external device through the communication interface;

updating at least one of the preset value and the preset time range based on the user command and storing it in the memory

robot.
According to claim 1,

A motor for providing power to the joint; further comprising,

The processor is

To obtain the first signal based on the position information of the link, the speed information of the link, and the position information of the motor

robot.
According to claim 1,

The processor is

inputting the first signal to a high-pass filter to obtain the second signal,

inputting the first signal to a low-pass filter to obtain the third signal

robot.
3. The method of claim 2,

The preset time range is determined based on a cutoff frequency for the first signal.

robot.
According to claim 1,

The processor is

When it is determined that the robot and the obstacle collide, the operation of the manipulator is stopped and a travel path is generated to avoid the obstacle.

robot.
In the control method of a robot comprising a manipulator (manipulator) including a joint and a link connected to the joint,

acquiring a first signal for an external force acting on the manipulator;

obtaining a second signal from which a low-frequency component of the first signal is removed and a third signal from which a high-frequency component of the first signal is removed; and

determining whether the robot collides with an obstacle by comparing the magnitude of the second signal and the magnitude of the third signal with a preset value;

control method.
10. The method of claim 9,

The determining step is

When a time period in which the magnitude of the third signal is greater than the preset value exists within a preset time range from the first time point when the magnitude of the second signal starts to become greater than the preset value, the robot and the obstacle collide judged to have

control method.
10. The method of claim 9,

The determining step is

If there is no time period in which the magnitude of the third signal is greater than the preset value, it is determined that the robot and the obstacle do not collide.

control method.
11. The method of claim 10,

obtaining a user command for setting at least one of the preset value and the preset time range from an external device; and

The method further comprising: updating and storing at least one of the preset value and the preset time range based on the user command

control method.
10. The method of claim 9,

Obtaining the first signal comprises:

To obtain the first signal based on the position information of the link, the speed information of the link, and the position information of a motor for providing power to the joint

control method.
10. The method of claim 9,

Obtaining the second signal comprises:

inputting the first signal to a high-pass filter to obtain the second signal,

Obtaining the third signal comprises:

inputting the first signal to a low-pass filter to obtain the third signal

control method.
11. The method of claim 10,

The preset time range is determined based on a cutoff frequency for the first signal.

control method.