KR102324773B1 - Walking control system of robot and method controlling the same - Google Patents

Abstract

Calculating a plurality of position data forming the outline of objects located in a specific area in a direction to walk; Recognizing at least one or more planes through the calculated plurality of position data; determining whether a preset gait pattern needs to be corrected based on the recognized plane data; and controlling the robot with the modified gait pattern when the gait pattern needs to be corrected, and controlling the robot with a preset gait pattern when the gait pattern does not need to be corrected. This is introduced.

Description

Robot walking control system and its control method

The present invention relates to a control method and system for securing walking stability by determining whether a front obstacle can walk when a robot walks.

A robot refers to a mechanical device that behaves similar to a human. In the early days, industrial robots, such as production robots, were developed to replace human tasks. However, recently, research on bipedal robots having the same shape as humans has been increasing, and wearable robots that can be worn by humans have been developed.

In particular, a robot that walks on two legs is unstable compared to a robot with three legs or more, so it is relatively complicated and difficult to control the gait. have

In general, in the case of a bipedal robot or a wearable robot, a gait pattern is set in advance and controlled according to the gait pattern. Specifically, the height of a foot of the robot, a stride length, etc. are preset and controlled according to the set gait pattern.

However, if it is impossible to walk according to the preset gait pattern because there is an obstacle in front, the gait direction must be changed or the gait pattern must be corrected in order to avoid this. Existing walking robots have a problem in that a separate manual operation is required to correct a gait pattern.

The matters described as the above background art are only for improving the understanding of the background of the present invention, and should not be taken as acknowledging that they correspond to the prior art already known to those of ordinary skill in the art.

KR 10-2008-0001228 A

The present invention has been proposed to solve this problem, and uses a sensor to recognize obstacles in a direction to walk, determine whether walking is possible, and control to an optimal walking pattern when walking is possible or when walking is impossible is to provide a robot walking control system that can bypass obstacles and a control method therefor.

A walking control system for a robot according to the present invention for achieving the above object includes: a sensor unit for sensing a plurality of position data forming the outline of objects located in a specific area in a direction to walk; an auxiliary control unit for recognizing at least one plane based on a plurality of position data sensed by the sensor unit; and a main controller that corrects the gait pattern based on the plane recognized by the auxiliary controller and controls the robot with the modified or preset gait pattern.

In order to achieve the above object, a control method using a robot walking control system according to the present invention includes: calculating a plurality of position data forming the outline of objects located in a specific area in a direction to walk; Recognizing at least one or more planes through the calculated plurality of position data; determining whether a preset gait pattern needs to be corrected based on the recognized plane data; and controlling the robot with the modified gait pattern when the gait pattern needs to be corrected, and controlling the robot with a preset gait pattern when the gait pattern does not need to be corrected.

In the step of calculating the plurality of position data, the position data of the camera coordinate system may be recognized, and the recognized camera coordinate system position data may be converted into World coordinate system position data.

The camera coordinate system position data recognized in the step of calculating a plurality of position data may be converted into world coordinate system position data based on IMU (Inertia Measurement Unit) sensor data.

Recognizing at least one plane may include classifying points belonging to the same plane by using a relationship between a plurality of calculated position data.

The plurality of position data is point data, and the step of recognizing at least one or more planes is to calculate a normal vector of each point using a relationship with adjacent points at each point, and compare the calculated normal vectors of each point. Points belonging to the same plane can be classified.

Recognizing the at least one plane may include calculating a plane equation using position data of points belonging to the classified same plane.

After recognizing the at least one or more planes, the method may further include re-classifying the same planes among the recognized planes.

The step of determining whether the preset gait pattern needs to be corrected is calculating the distance, height and area of the plane based on the recognized plane data, and calculating the distance, height, and area of the plane based on the calculated distance, height, and area of the plane for preset gait. It can be determined whether a person can walk in a pattern.

The controlling of the robot may further include determining whether it is possible to walk on a recognized plane when it is necessary to modify the gait pattern.

The step of determining whether walking on the recognized plane is possible is calculating the angle, distance, height and area of the recognized plane, and whether walking on the recognized plane is possible based on the calculated angle, distance, height and area of the plane can be judged

In the step of determining whether walking on the recognized plane is possible, if it is determined that walking is impossible, the robot may be controlled to change the walking direction, reposition, or wait.

According to the gait control system and the control method of the robot of the present invention, there is an effect that it is possible to ensure the safety of the robot or the wearer by determining whether the walking robot or the wearable robot can walk with respect to an obstacle located in the walking direction when walking. .

In addition, it has the effect of controlling the gait quickly and conveniently by automatically correcting the gait pattern without a separate manual operation.

1 shows the configuration of a robot and a robot walking control system according to an embodiment of the present invention.
2 is a flowchart of a method for recognizing a plane of a robot according to an embodiment of the present invention.
3 is a flowchart illustrating a method for controlling a walk of a robot according to an embodiment of the present invention.

Specific structural or functional descriptions of the embodiments of the present invention disclosed in the present specification or application are only exemplified for the purpose of describing the embodiments according to the present invention, and the embodiments according to the present invention may be implemented in various forms. and should not be construed as being limited to the embodiments described in the present specification or application.

Since the embodiment according to the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the present specification or application. However, this is not intended to limit the embodiment according to the concept of the present invention with respect to a specific disclosed form, and should be understood to include all changes, equivalents or substitutes included in the spirit and scope of the present invention.

Terms such as first and/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 component from another, for example, without departing from the scope of rights according to the inventive concept, a first component may be termed a second component, 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 is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is said 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", 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. In this specification, terms such as "comprises" or "have" are intended to designate that the described features, numbers, steps, operations, components, parts, or combinations thereof exist, and include one or more other features or numbers. , it should be understood that it does not preclude the existence or addition of steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and 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 commonly used dictionaries should be interpreted as meanings consistent with the context of the related art, and unless explicitly defined in the present specification, they are not to be interpreted in an ideal or excessively formal meaning. .

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. Like reference numerals in each figure indicate like elements.

1 shows the configuration of a robot and a robot walking control system according to an embodiment of the present invention.

A walking control system for a robot according to an embodiment of the present invention includes: a sensor unit 10 for sensing a plurality of position data forming the outline of objects located in a specific area in a direction to walk; an auxiliary control unit 20 for recognizing at least one plane based on a plurality of position data sensed by the sensor unit 10; and a main controller 30 that corrects the gait pattern based on the plane recognized by the auxiliary controller 20 and controls the robot with the modified or preset gait pattern.

The sensor unit 10 may be configured as a stereo camera or a depth sensor capable of three-dimensional spatial recognition. Here, an Inertial Measurement Unit (IMU) capable of measuring an absolute angle may be further included. The sensor unit 10 may sense any area, but for gait control, it will sense a specific area in a direction in which the robot wants to walk.

The IMU sensor uses a magnetic field accelerometer and a gyroscope to calculate angular velocity, linear velocity, and position. In the present invention, the position and pitch, roll and yaw data of the sensor unit 10 can be sensed through this.

The sensor unit 10 may sense position data such as a plurality of points, straight lines, planes, etc. forming the outer edges of objects located in the sensing region. The present invention will be described as sensing a plurality of points forming the outline of objects. The sensor unit 10 senses the position data of a plurality of points, but may convert the three-dimensional position data sensed by the camera coordinate system into the world coordinate system by the absolute angle sensed by the IMU sensor.

The auxiliary control unit 20 may recognize a plane based on a plurality of position data sensed by the sensor unit 10 . A specific plane recognition method will be described in the control method below.

The main controller 30 may correct the gait pattern based on the plane recognized by the auxiliary controller 20 and control the robot with the modified or preset gait pattern. Specifically, the main control unit 30 can control the torque of the robot's joints or control the rotation angle, etc. in the case of an articulated robot, and in the case of a wire-type robot, control the tension and length of the wire, etc. can control the walking pattern of the walking robot.

2 is a flowchart illustrating a method for recognizing a plane of a robot according to an embodiment of the present invention, and FIG. 3 is a flowchart illustrating a method for controlling a walk of a robot according to an embodiment of the present invention.

A control method according to an embodiment of the present invention using a walking control system of a robot comprises: calculating a plurality of position data forming the outline of objects located in a specific area in a direction to walk (S100); Recognizing at least one plane through a plurality of calculated position data (S200); Determining whether a preset gait pattern needs to be corrected based on the recognized plane data (S300); and controlling the robot with the modified gait pattern when the gait pattern needs to be corrected, and controlling the robot with a preset gait pattern when the gait pattern does not need to be corrected ( S500 ).

In the step of calculating the position data ( S100 ), the sensor unit may calculate a plurality of position data forming the outline of objects located in a specific area in a direction to walk. The sensor unit may recognize position data of the camera coordinate system and IMU (Inertia Measurement Unit) sensor data. The recognized camera coordinate system position data can be converted into coordinate system position data based on the recognized IMU sensor data.

For example, in the camera coordinate system, the camera optical axis direction can be defined as Zc, the right side is Xc, and the bottom side is Yc. have.

The three-dimensional position data sensed by the sensor unit through a stereo camera or a depth sensor capable of three-dimensional spatial recognition may be sensed in the camera coordinate system (S110). The three-dimensional position data sensed by the camera coordinate system may be converted into the world coordinate system based on the camera position sensed by the IMU sensor, the left and right rotation angle of the camera, and the vertical rotation angle of the camera (S120). Since the conversion formula for this is a well-known technique, a detailed description thereof will be omitted. The sensor unit may obtain three-dimensional position data made of the converted world coordinate system, and may transmit it to the auxiliary control unit (S130).

In the step of recognizing at least one plane through the calculated plurality of position data (S200), the auxiliary controller may classify points belonging to the same plane (S220). Specifically, the points belonging to the same plane are classified using the relationship between the plurality of three-dimensional position data transformed into the World coordinate system (S220), and the plane equation is calculated using the position data of the classified points belonging to the same plane. It can be done (S230).

As an embodiment, in a method of classifying points belonging to the same plane, a normal vector of a point may be calculated using a relationship with adjacent points at each point using a plurality of position data made of point data ( S210).

)에서 인접한 점(

)과의 관계를 이용하여 각각의 점에서

을 만족하는 Normal 벡터를 산출할 수 있다(S210).That is, each point (

) at an adjacent point (

) at each point using the relationship with

It is possible to calculate a normal vector that satisfies (S210).

을 만족하는 경우 동일한 평면에 속하는 점으로 분류할 수 있다(S220). 동일한 평면에 속하는 것으로 분류된 복수의 점들의 위치 데이터를 이용하여 평면방정식을 산출할 수 있다(S230).Also, points belonging to the same plane can be classified by comparing the calculated normal vectors of each point. That is, the normal vectors of adjacent points are

When , it can be classified as a point belonging to the same plane (S220). A plane equation may be calculated using position data of a plurality of points classified as belonging to the same plane (S230).

으로 정의할 수 있고, 이에 대한 a, b, c, d의 파라미터를 산출할 수 있다. 구체적으로, 아래의 수학식에 복수의 점들의 위치 데이터를 대입하고, SVD(Singular Value Decomposition, 특이값 분해) 또는 QR Decomposition 등의 수치해석적인 연산 방법 등에 의하여 a, b, c, d의 파라미터를 산출하여 평면방정식을 산출할 수 있다.In one embodiment, the plane equation in three-dimensional space

can be defined, and parameters of a, b, c, and d can be calculated. Specifically, by substituting the position data of a plurality of points into the following equation, the parameters of a, b, c, and d are calculated by numerical analysis methods such as SVD (Singular Value Decomposition) or QR Decomposition. It is possible to calculate the plane equation by calculation.

A method of deriving the parameters of a, b, c, and d through SVD (singular value decomposition), among the above calculation methods, is a well-known technique in the field of numerical analysis, so a description of specific embodiments will be omitted.

After the step of recognizing at least one or more planes (S200), the step of reclassifying the same planes among the recognized planes (240) may be further included. This step is to reclassify the same plane since the auxiliary controller can divide and detect the same plane into a plurality of parts.

For example, since a new obstacle such as a stick exists in one plane and one plane can be divided into multiple, even in this case, the same plane is a process of merging to be recognized as one plane. Accordingly, when the plane equations are the same or similar, they are classified as the same plane, and after this step, the plane can be recognized by checking whether the three-dimensional position data of the plurality of points are included in the calculated plane.

Determining whether the preset gait pattern needs to be corrected (S300) is to calculate the distance and height of the plane based on the plane data recognized by the auxiliary controller to determine whether it is possible to walk on the plane recognized by the preset gait pattern. have. Based on the plane data recognized in the step of recognizing the plane (S200) above, the distance and height of the corresponding plane may be calculated from the position of the robot.

Specifically, it is determined whether the gait pattern should be corrected by calculating the distance, height, and area to the recognized plane based on the position of the robot's foot. Here, the gait pattern means the moving distance and height of the moving foot of the robot when walking. In general, when a walking robot walks on a flat surface, the height and distance of the robot's feet are controlled by a preset walking pattern. However, if there is an obstacle in the walking direction, it is determined whether the robot's feet can be controlled by a preset walking pattern. That is, when the robot's foot is controlled by a preset walking pattern, whether the robot's foot is safely supported on the recognized plane is determined by the distance, height, and area of the plane.

When the gait pattern needs to be corrected, the robot is controlled with the modified gait pattern, and when there is no need to modify the gait pattern, the step of controlling the robot with the preset gait pattern (S500) is the gait pattern modified or preset by the main controller. can control the robot. That is, if it is determined that there is no problem in gait even if the feet of the robot are controlled with the preset gait pattern, the robot is controlled with the preset gait pattern (S510). It is possible to control the robot with a pattern (S520).

Specifically, the main controller controls the feet of the robot, and by controlling the joints of the robot, it is possible to control the feet of the robot to operate in a preset gait pattern or a modified gait pattern.

The step of controlling the robot (S500) may further include a step (S400) of determining whether it is possible to walk on a recognized plane when the gait pattern needs to be corrected. That is, when it is recognized that the correction of the gait pattern is necessary, it may be first determined whether the robot can walk on the recognized plane ( S400 ).

The step of determining whether walking on the recognized plane is possible (S400) is to calculate the angle, distance, height and area of the recognized plane, and whether walking on the recognized plane is possible based on the calculated angle, distance, height and area can determine whether

Specifically, if the angle of the recognized plane is steep above a certain level or the height is high enough to drive the robot's foot, it is determined whether the recognized plane is very narrow, etc. to determine whether walking on the recognized plane is possible. to judge whether

When it is determined that walking is possible, the gait pattern may be modified to correct the moving distance and height of the foot of the moving robot, and the robot may be controlled with the modified gait pattern (S520).

When it is determined that walking is impossible, the robot may be controlled to change the direction of the robot's walking, readjust the position of the robot, or stop the walking and wait for the robot (S530). The walking direction of the switching robot can be set automatically, or the user can manually designate a new one. If walking is impossible from the current position, such as when the distance from the recognized plane information is too close or too far, the robot may be moved to a gaitable position by re-adjusting the position. When the robot stops walking and waits, a siren, a signal, a light, etc. can be used to notify the user that the robot is waiting.

Although shown and described with respect to specific embodiments of the present invention, it is understood in the art that the present invention can be variously improved and changed without departing from the spirit of the present invention provided by the following claims. It will be obvious to those of ordinary skill in the art.

10: sensor unit 20: auxiliary control unit
30: main fisherman
S100: Calculating location data
S200: Recognizing a plane
S300: a step of determining whether a preset gait pattern needs to be corrected
S400: Step of determining whether walking is possible
S500: Step of controlling the robot according to the gait pattern

Claims (12)

a sensor unit configured to sense a plurality of position data forming the outline of objects located in a specific area in a direction to walk;
an auxiliary control unit recognizing at least one plane based on a plurality of position data sensed by the sensor unit and reclassifying the same planes among the recognized planes; and
A gait control system of a robot comprising a; a main controller that corrects a gait pattern based on the plane recognized by the auxiliary controller, and controls the robot with a modified or preset gait pattern. The control method using the walking control system of the robot of claim 1,
Calculating a plurality of position data forming the periphery of objects located in a specific area in a direction to walk;
Recognizing at least one or more planes through the calculated plurality of position data;
reclassifying the same planes among the recognized planes;
determining whether a preset gait pattern needs to be corrected based on the recognized plane data; and
When the gait pattern needs to be corrected, controlling the robot with the modified gait pattern, and when there is no need to modify the gait pattern, controlling the robot with a preset gait pattern. 3. The method according to claim 2,
The step of calculating a plurality of position data recognizes the position data of the camera coordinate system, and converts the recognized camera coordinate system position data into World coordinate system position data. 4. The method according to claim 3,
The camera coordinate system position data recognized in the step of calculating a plurality of position data is a walking control method of a robot, characterized in that it is converted into World coordinate system position data based on IMU (Inertia Measurement Unit) sensor data. 3. The method according to claim 2,
The step of recognizing at least one or more planes comprises classifying points belonging to the same plane by using a relationship between a plurality of calculated position data. 6. The method of claim 5,
The plurality of position data is point data, and the step of recognizing at least one or more planes is to calculate a normal vector of each point using a relationship with adjacent points at each point, and compare the calculated normal vectors of each point. A gait control method of a robot, characterized in that the points belonging to the same plane are classified. 6. The method of claim 5,
The step of recognizing at least one plane comprises calculating a plane equation using position data of points belonging to the classified same plane. delete 3. The method according to claim 2,
The step of determining whether the preset gait pattern needs to be corrected is calculating the distance, height and area of the plane based on the recognized plane data, and calculating the distance, height and area of the plane based on the calculated distance, height, and area of the plane for preset gait. A gait control method of a robot, characterized in that it is determined whether it can walk in a pattern. 3. The method according to claim 2,
The step of controlling the robot further comprises the step of determining whether walking on the recognized plane is possible when the gait pattern needs to be corrected. 11. The method of claim 10,
The step of determining whether walking on the recognized plane is possible is calculating the angle, distance, height and area of the recognized plane, and whether walking on the recognized plane is possible based on the calculated angle, distance, height and area of the plane A gait control method of a robot, characterized in that determining a. 11. The method of claim 10,
In the step of determining whether walking on the recognized plane is possible, if it is determined that walking is impossible, the method for controlling the robot to walk, characterized in that the robot is controlled to change the walking direction, readjust the position, or wait.

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