KR101052518B1 - Articulated Robot Control Method and Control System - Google Patents

Abstract

An articulated robot control method and control system are disclosed. CLAIMS What is claimed is: 1. A method of controlling a articulated robot based on a reference posture intended by a user, comprising: acquiring first encoder data about a preset calibration posture of the robot; Acquiring offset data of the calibration attitude relative to the reference attitude; Acquiring second encoder data about a current posture of the robot; And acquiring relative position data of the current pose with respect to the reference pose using the first encoder data, the second encoder data, and the offset data. Position control can be enabled by single use of.

Articulated, Robotic, Calibration, Control

Description

Multi-joint robot control method and control system {Controlling Method and System for Multi-Joint Robot}

The present invention relates to a multi-joint robot control method and control system.

Background Art In general, industrial robots have become increasingly popular as absolute position detectors (absolute encorders) as position detectors for detecting position information of joints and arm portions driven by driving sources. The robot equipped with such an absolute position detector should correct the posture which is the reference of the robot immediately after assembly production and according to the needs of the operator during use, and the kinematics of calibrating each arm parameter of the assembled state to actual values. Only a calibration is required to perform precise work.

However, in the conventional reference posture and position calibration method, since the robot arm is moved to a predetermined position and posture, the position detector is re-adjusted using a pre-calculated joint variable corresponding to the position and posture. And it is very inefficient, such as requiring effort and work time, there was a problem that results in a decrease in the accuracy of the robot.

The present invention is to provide a multi-joint robot control method and control system capable of position control by one-time use of absolute encoder data.

According to an aspect of the present invention, a method of controlling a multi-joint robot based on a reference posture intended by a user, the method comprising: obtaining first encoder data about a preset calibration posture of the robot; Acquiring offset data of the calibration attitude relative to the reference attitude; Acquiring second encoder data about a current posture of the robot; And acquiring relative position data of the current posture with respect to the reference posture using the first encoder data, the second encoder data, and the offset data.

The acquiring of the first encoder data may include actuating respective joints of the robot in correspondence to calibration coordinate data of the robot according to a Cartesian coordinate system, and acquiring the offset data may include: According to the reference coordinate data of the robot according to the above, it may include the step of operating the respective joints of the robot in the calibration posture.

Meanwhile, the method may further include providing target pose data to the robot so that the robot has a target pose, and the target pose data may be incremental encoder data.

According to another aspect of the present invention, a robot control system for controlling the articulated robot based on a reference posture intended by a user, the robot having a plurality of joints each having an encoder; And a controller configured to control the behavior of the robot by receiving data from the respective encoders, wherein the controller includes first encoder data of a preset calibration posture of the robot and a calibration posture of the reference posture. The robot control system may be configured to acquire relative position data of the current pose with respect to the reference pose using the relative offset data and the second encoder data about the current pose of the robot.

The controller acquires the first encoder data by operating the joints of the robot according to the coordinate coordinate data of the robot according to the Cartesian coordinate system, and corresponds to the reference coordinate data of the robot according to the Cartesian coordinate system. The offset data may be obtained by operating each joint of the robot in a posture.

The controller may provide target pose data to the robot such that the robot has a target pose, and the target pose data may be incremental encoder data.

Meanwhile, the controller may sequentially receive data from each of the encoders using a relay.

According to embodiments of the present invention, multiple encoder communication channels and one controller communication channel can be efficiently used, and position control can be enabled by one use of absolute encoder data. In addition, even when the absolute encoder is used, the control may be performed using incremental encoder data during position control.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, preferred embodiments of the articulated robot control method and control system according to the present invention will be described in detail with reference to the accompanying drawings, and in the following description with reference to the accompanying drawings, the same or corresponding components are provided with the same reference numerals. And duplicate description thereof will be omitted.

1 is a flowchart illustrating a method for controlling the articulated robot 100 according to an embodiment of the present invention. According to the present embodiment, first, the first encoder data D _E1 for the preset calibration attitude of the robot 100 is acquired (S10). Calibration posture of the robot 100, more specifically, the calibration of each joint J ₁ , J ₂ , J ₃ , J ₄ , J ₅ , J ₆ and each arm 111, 112, 113, 114, 115, 116 The posture (see FIG. 2B) may be predetermined by a seller who manufactures and sells the robot 100, and the position data thereof may also be previously given as a coordinate value according to a rectangular coordinate system. An example of a calibration posture is illustrated in FIG. 2B, but may be variously changed according to design needs.

Therefore, when the robot 100 is initially purchased and the robot 100 is placed in the initial position (see FIG. 2A), the robot 100 is moved to the calibration position (see FIG. 2B) by using a means such as a measuring instrument. During this time, the rotation amount (or angle value) generated at each joint is acquired / stored as the first encoder data D _E1 . Each joint J ₁ , J ₂ , J ₃ , J ₄ , J ₅ , J ₆ may be rotated by a motor (not shown), in which case the first encoder data D _E1 is coupled to each motor. It can be detected and acquired by an encoder (not shown). Each process described above may be performed by means such as a control unit 300 of FIG. 4 of the articulated robot control system.

On the other hand, as described above, since the calibration posture (see FIG. 2B) may be predetermined by a seller who manufactures and sells the robot 100, the first encoder data D _E1 may be calibrated unless there is a special situation. It can be determined from the posture itself, and once acquired and stored, the stored value can be used again without a separate acquisition process later. Therefore, if the first encoder data D _E1 for the calibration attitude has been previously acquired and stored, the above-described process may be omitted.

Next, the offset data D _O of the calibration attitude with respect to the reference attitude is acquired (S20). Here, the reference posture (see FIG. 2C) refers to a posture arbitrarily set by the user of the robot 100 to control the robot 100, and may be set differently for each user. In addition, the offset data D _O denotes a relative difference of the calibration posture with respect to the reference posture. The position data of the reference attitude (see FIG. 2C) may also be previously given as a coordinate value according to the rectangular coordinate system.

In order to obtain the offset data D _O , the robot 100 placed in the calibration posture (see FIG. 2B) is moved to the reference posture (see FIG. 2C) by means of a measuring instrument or the like, during which each joint ( The amount of rotation (or angle value) generated by J ₁ , J ₂ , J ₃ , J ₄ , J ₅ , J ₆ ) is acquired / stored as offset data D _O. Each joint may be rotated by a motor (not shown). In this case, the offset data D _O may be detected and acquired by an encoder (not shown) coupled to each motor. Each process described above may be performed by means such as a control unit 300 of FIG. 4 of the articulated robot control system. Naturally, if the reference attitude and the calibration attitude are the same, the offset data is zero.

Meanwhile, as described above, since the calibration posture (see FIG. 2B) and the reference posture (see FIG. 2C) may be predetermined by the seller and the user, the offset data D _O is the calibration posture itself unless there is a special situation. Once acquired and stored, the stored value can be used again without additional acquisition process. Therefore, if the offset data has been previously acquired and stored, the above-described process may be omitted.

Next, the second encoder data D _E2 for the current posture of the robot 100 is acquired (S30). Here, the current posture of the robot (see FIG. 3A) refers to the posture of the robot 100 at the time when the control program for the robot 100 is driven. The second encoder data D _E2 may also be detected and acquired by an encoder (not shown) coupled to a motor that drives each joint J ₁ , J ₂ , J ₃ , J ₄ , J ₅ , J ₆ . have.

Then, the positional data D _C of the current pose (see FIG. 3A) relative to the reference pose (see FIG. 2C) is obtained (S40). To this end, the first encoder data D _E1 , the second encoder data D _E2 , and the offset data D _O may be used. That is, the relative position data from the current position to the reference position _(C D) may be obtained through the equation below.

D _C = (D _E2 -D _E1 ) * (deg.mm / pulse) + D _O

here,

D _E2 is the second encoder data of the corresponding joint with respect to the robot's current pose,

D _E1 is the first encoder data of the corresponding joint for the robot's calibration position,

D _O is offset data of the corresponding joint of the calibration posture with respect to the reference posture.

When the robot 100 is initially purchased and moved to acquire the first encoder data D _E1 and the offset data D _O , the reference pose becomes the current pose. 'S posture becomes the current posture.

After acquiring the position data D _C of the current pose relative to the reference pose using the above method, the target pose data is provided to the robot 100 to have the target pose (see FIG. 3B) (S50). The target posture refers to the posture of the robot 100 intended by the user for the work using the robot 100.

In this case, the target attitude data provided to the robot 100 may be incremental encoder data. Since the position of the robot 100 is initialized based on the reference posture through the above-described process, in controlling the position of the robot 100 thereafter, the robot 100 can be sufficiently controlled with only incremental encoder data. As such, providing incremental encoder data to the robot 100 may be performed by means such as a control unit 300 of the articulated robot control system, which will be described later.

In the above described the method for controlling the articulated robot 100 according to an embodiment of the present invention, hereinafter will be described for the articulated robot control system according to another embodiment of the present invention.

4 is a view illustrating a multi-joint robot control system according to another embodiment of the present invention. Referring to FIG. 4, the multi-joint robot 100 and an arm Arm 111, 112, 113, 114, 115, and 116 are illustrated. Joint, J ₁ , J ₂ , J ₃ , J ₄ , J ₅ , J ₆ , robot 100, base 120, relay 200, controller 300, CPU 310, Memory 320 is shown.

In general, the robot 100 for work should always be aware of its position even when starting work in any situation or posture, and is controlled using an absolute encoder (Absolute Encoder) mainly for the convenience of system configuration. The absolute encoder outputs the position value through a means such as 485 communication.

The articulated robot control system according to the present embodiment includes a robot 100 having a plurality of joints each having an encoder, and a controller for controlling the behavior of the robot 100 by receiving data from the respective encoders. do. In this case, the controller uses first encoder data about the calibration attitude of the robot 100 preset, relative offset data of the calibration attitude with respect to the reference attitude, and second encoder data about the current attitude of the robot 100. In addition, the position data of the current pose relative to the reference pose is acquired.

The method of acquiring the first encoder data D _E1 , the offset data D _O of the calibration attitude with respect to the reference attitude, and the second encoder data D _E2 with respect to the current attitude of the robot 100 are described above. Since the same / similar to that described in the articulated robot control method, a detailed description thereof will be omitted. The CPU 310 is provided in the control unit 300 for data transmission and reception with the articulated robot 100.

On the other hand, as described above, the first encoder data D _E1 and the offset data D _O are determined by the calibration attitude, and once acquired and stored unless there is a special situation, the stored values are stored again without additional acquisition process. Since it can be used, the control unit 300 is provided with a memory 320 for storing them.

On the other hand, according to the present embodiment, by using the MUX method of 1: n (control unit communication channel: absolute encoder), the multi-channel encoder communication data is received through one control channel. To this end, a relay 200 that connects n encoder channels CH ₁ , CH ₂ , CH ₃ , CH ₄ , CH ₅ , and CH ₆ sequentially to a controller communication channel can be driven.

More specifically, after assigning a number to each joint (J ₁ , J ₂ , J ₃ , J ₄ , J ₅ , J ₆ ) of each robot 100 constituting the system, to perform encoder data communication Outputs a relay-on signal corresponding to the joint, and connects the encoder data communication channel with the communication channel of the control unit 300. When the encoder data collection is completed, the relevant relay-off signal is output and the next encoder channel relay-on signal is output to receive absolute encoder data. Encoder data received sequentially stores its value in a constant variable. Subsequently, each joint J of the current robot 100 using the received encoder data (second encoder data, D _E2 ), data about a calibration posture (first encoder data, D _E1 ), and offset data (D _O ). ₁ , J ₂ , J ₃ , J ₄ , J ₅ , J ₆ ) and the robot posture are calculated. When the position of each joint of the robot is calculated, the six degree of freedom posture can be calculated automatically.

Thereafter, when the target posture data for the robot 100 is provided, the controller 300 may transmit a signal such that the robot 100 has the target posture (see FIG. 3B) so that the target posture is implemented. In this case, the target attitude data provided to the robot 100 may be incremental encoder data. Since the position of the robot 100 has already been initialized based on the reference attitude (see FIG. 2C), the robot 100 can be sufficiently controlled with only incremental encoder data in controlling the position of the robot 100 thereafter.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention.

1 is a flowchart illustrating a method for controlling a jointed-arm robot according to an embodiment of the present invention.

2A to 2C are diagrams illustrating a process of acquiring first encoder data and offset data for a calibration posture in a multi-joint robot control method according to an embodiment of the present invention.

3A and 3B are views illustrating a process of changing from a current posture to a target posture in a multi-joint robot control method according to an embodiment of the present invention.

4 is a view showing the articulated robot control system according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: articulated robot

111, 112, 113, 114, 115, 116: Arm

J ₁ , J ₂ , J ₃ , J ₄ , J ₅ , J ₆ : Joint

120: robot base

200: relay

300: control unit

310: CPU

320: memory

Claims (7)

As a method of controlling the articulated robot based on a reference posture intended by a user, Acquiring first encoder data about a preset calibration attitude of the robot; Acquiring offset data of the calibration attitude relative to the reference attitude; Acquiring second encoder data about a current posture of the robot; And And acquiring position data of the current pose relative to the reference pose using the first encoder data, the second encoder data, and the offset data. The method of claim 1, The acquiring of the first encoder data may include actuating respective joints of the robot, corresponding to calibration coordinate data of the robot according to a rectangular coordinate system. The acquiring the offset data may include operating each joint of the robot in a calibration position corresponding to the reference coordinate data of the robot according to a Cartesian coordinate system. The method according to claim 1 or 2, Providing target position data to the robot such that the robot has a target position; And the target pose data is incremental encoder data. A robot control system that controls a multi-joint robot based on a reference posture intended by a user, A robot having a plurality of joints each having an encoder; A control unit for receiving data from each of the encoders and controlling the behavior of the robot; The control unit, First encoder data about a preset calibration attitude of the robot; Offset data relative to the calibration attitude with respect to the reference pose, and And position data of the relative position of the current position with respect to the reference position using the second encoder data of the current position of the robot. 5. The method of claim 4, The control unit, Corresponding to the calibration coordinate data of the robot according to the Cartesian coordinate system, the respective joints of the robot are operated to acquire the first encoder data, And corresponding offset data of the robot according to a Cartesian coordinate system, the robot control system acquiring the offset data by operating each joint of the robot in a calibration posture. The method according to claim 4 or 5, The control unit, To provide the target attitude data to the robot, so that the robot has a target posture, And the target attitude data is incremental encoder data. The method according to claim 4 or 5, The control unit, Robot control system, characterized in that receiving data sequentially from each of the encoder using a relay (Relay).

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