Industrial robot and control method, device and readable storage medium thereof

Abstract

The application provides an industrial robot, a control method, device and readable storage medium thereof. The industrial robot comprises a joint driver, a motor and a connecting rod. The joint driver drives the motor to drive the connecting rod to move. The control method comprises the following steps: receiving first control information; acquiring discrete points in first path information, the discrete points being associated with a planned speed curve, the first path information being path information corresponding to the first control information; acquiring a corresponding relationship between vibration suppression parameters of the motor and the discrete points when the joint driver operates according to the speed curve; in the case that a joint target position is received, determining position increment information corresponding to the joint target position based on the corresponding relationship; and controlling the motor to operate based on the position increment information.

Description

Technical Field

[0001] This invention relates to the field of control technology, and more specifically, to an industrial robot and its control method, apparatus, and readable storage medium. Background Technology

[0002] Taking a robotic arm as an example, industrial robots have a connection load such as a reducer and a belt between their motor and the link, which makes the motor and the link of the robotic arm flexible. This flexibility is called joint flexibility.

[0003] Specifically, the path planned by the controller of the robotic arm is the path desired by the link. However, due to the flexibility of the joint, the position of the motor is inconsistent with the position of the link. Under the proportional, integral and derivative (PID) control of the driver, vibration eventually occurs, which seriously affects the path accuracy.

[0004] To ensure that the robotic arm can operate with high control precision, the joint stiffness of the robotic arm is calibrated. Based on the calibration results, a rigid-flexible dynamic model of the joint is established. The trajectory of the motion plan needs to be shaped by the rigid-flexible dynamic model before it can be sent to the joint actuator.

[0005] However, the joint stiffness and torque exhibit a nonlinear relationship, making the calibration process complex and costly. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0007] Therefore, a first aspect of the present invention is to provide a control method for an industrial robot.

[0008] A second aspect of the present invention is that a control device for an industrial robot is provided.

[0009] A third aspect of the invention is that it provides another control device for an industrial robot.

[0010] A fourth aspect of the present invention is that a readable storage medium is provided.

[0011] A fifth aspect of the present invention is that an industrial robot is provided.

[0012] In view of the above, according to a first aspect of the present invention, the present invention provides a control method for an industrial robot, the industrial robot including a joint actuator, a motor and a link, the joint actuator driving the motor to move the link, the control method including: receiving first control information; acquiring discrete points in first path information, the discrete points being associated with a planned velocity curve, the first path information being path information corresponding to the first control information; acquiring the correspondence between the vibration suppression parameters of the motor and the discrete points when the joint actuator is running according to the velocity curve; upon receiving a joint target position, determining position increment information corresponding to the joint target position based on the correspondence; and controlling the motor to run based on the position increment information.

[0013] The technical solution of this invention proposes a control method for industrial robots. By running the above control method, the motor can be controlled based on position increment information, thereby suppressing the vibration of the motor and ensuring the control accuracy of the industrial robot.

[0014] In related technical solutions, calibrating the joint stiffness of industrial robots requires users to pay the robot manufacturer for expensive equipment to perform the calibration and obtain calibration parameters. However, the control method for industrial robots proposed in this invention allows the robot to directly suppress vibration by operating the aforementioned control method, eliminating the need for joint stiffness calibration and thus reducing the cost of vibration suppression.

[0015] Meanwhile, the control method proposed in this invention can quickly suppress joint vibrations according to the on-site working conditions, without waiting for manufacturer calibration, thus minimizing the impact of vibrations on industrial robot operations.

[0016] Furthermore, the control method for industrial robots proposed in this invention eliminates the need to construct rigid-flexible dynamics models, thus reducing the workload required for industrial robots to suppress vibrations.

[0017] The technical solution of the present invention is based on the following principle: after receiving the first control information, the calibration of the correspondence between the vibration suppression parameters of the motor and discrete points under the first path information is triggered, thereby obtaining the correspondence.

[0018] After obtaining the correspondence, the position increment information corresponding to the target position of the joint can be determined based on the correspondence, so as to control the motor operation based on the position increment information.

[0019] In some technical solutions, the joint actuator can optionally be understood as a driver used to drive the motor to rotate.

[0020] In some technical solutions, the first control information may optionally be control information or control commands for the user to initiate vibration suppression.

[0021] In some technical solutions, the first control information may optionally be the user actively activating the vibration suppression function, or the control information automatically generated by the industrial robot when the motor generates low-frequency vibrations below 20Hz.

[0022] In some technical solutions, optionally, when the industrial robot is a robotic arm, the first path information can be understood as the path planned by the controller of the robotic arm, that is, the given path.

[0023] In some technical solutions, discrete points can optionally be understood as points in the path corresponding to the first path information.

[0024] In some technical solutions, the target position of the joint can optionally be understood as the position of the link.

[0025] In some technical solutions, the position increment information can optionally be understood as the increase in the motor position.

[0026] In addition, the industrial robot control method proposed in this invention has the following additional technical features.

[0027] In some technical solutions, optionally, the first path information includes multiple discrete points, and the velocity curve includes multiple sub-velocity curves that correspond one-to-one with the multiple discrete points. Obtaining the correspondence between the motor's vibration suppression parameters and the discrete points when the joint actuator runs according to the velocity curves specifically includes: controlling the joint actuator to run sequentially according to the multiple sub-velocity curves until the multiple sub-velocity curves have finished running; wherein, when the joint actuator runs according to each sub-velocity curve, the following steps are performed: obtaining the motor's vibration parameters; obtaining the quality factor corresponding to the vibration parameters; associating and storing the discrete points, vibration parameters, and quality factors corresponding to the sub-velocity curves to obtain the correspondence.

[0028] In this technical solution, the first planned path is divided into multiple discrete points, and a corresponding sub-velocity curve is planned for each discrete point. This allows the joint actuator to excite low-frequency vibration of the motor when running according to the sub-velocity curve, thereby enabling the measurement of the motor's vibration parameters.

[0029] Specifically, during the process of the joint actuator running according to multiple sub-velocity curves one by one, low-frequency vibrations of the motor can be excited at each discrete point. By collecting the vibration parameters of the motor, the low-frequency vibrations can be collected and expressed using the vibration parameters. Then, the detected vibration parameters are associated with the corresponding discrete points and stored to realize the acquisition of the corresponding relationship.

[0030] In the above technical solution, by obtaining the quality factor corresponding to the vibration parameters, a physical quantity representing the damping properties of the oscillator can be used, which can also represent the magnitude of the oscillator's resonant frequency relative to the bandwidth. This facilitates the determination of position increment information based on the correspondence.

[0031] In some technical solutions, the vibration parameters optionally include a first frequency and a second frequency in the frequency domain; wherein the first frequency and the second frequency are the two frequencies with the largest amplitude in the frequency domain.

[0032] In this technical solution, by defining the vibration parameters as including a first frequency and a second frequency in the frequency domain, two vibration frequencies can be suppressed simultaneously. Using this method, for adjacent joints that are in the same direction, the vibration suppression of two joints can be simplified to the vibration suppression of the two frequencies of the joint closest to the first joint, which simplifies the adaptive vibration suppression method and improves the stability and scalability of vibration suppression.

[0033] In some technical solutions, the control method may optionally include: fitting a first curve between discrete points and vibration parameters based on the correspondence; and fitting a second curve between discrete points and quality factors based on the correspondence.

[0034] In this technical solution, a first curve and a second curve are obtained by fitting, so that the position increment information can be determined based on the first curve and the second curve.

[0035] In some technical solutions, optionally, upon receiving the joint target position, the position increment information corresponding to the joint target position is determined based on the correspondence relationship. Specifically, this includes: obtaining a transfer function that expresses the motor position increment and the joint position increment in parallel; matching the target discrete point corresponding to the joint target position; determining the vibration suppression parameter corresponding to the target discrete point based on the correspondence relationship; and determining the position increment information corresponding to the joint target position based on the transfer function and the vibration suppression parameter corresponding to the target discrete point.

[0036] In this technical solution, by obtaining the transfer function expressed in parallel form, the transfer function can be split into two parallel parts. Compared with the transfer function expressed in serial form, error amplification can be reduced, and the robustness of vibration suppression can be maximized.

[0037] Furthermore, by using a transfer function expressed in parallel, the vibration suppression parameters corresponding to the target discrete point can be applied to different frequencies, thereby achieving vibration suppression at two frequencies.

[0038] In some technical solutions, optionally, motor operation is controlled based on position increment information, specifically including: acquiring first position information of the motor, the first position information being the position information of the motor at the previous moment; determining command position information of the motor based on the position increment information and the first position information; and controlling motor operation based on the command position information.

[0039] In this technical solution, the control of motor operation based on position increment information is refined. In this process, the position increment information can be superimposed on the position information of the motor at the previous moment to obtain the command position information of the motor. Then, the motor is controlled to run according to the command position information of the motor, thereby achieving vibration suppression.

[0040] During this process, the motor can continue to run as it changes over time, thereby continuously updating the first position information and position increment information, and then continuously updating the command position information of the motor to achieve continuous vibration suppression and ensure the control accuracy of the industrial robot.

[0041] According to a second aspect of the present invention, a control device for an industrial robot is provided. The industrial robot includes a joint actuator, a motor, and a link. The joint actuator drives the motor to move the link. The control device includes: a receiving unit for receiving first control information; a first acquiring unit for acquiring discrete points in first path information, wherein the discrete points are associated with a planned velocity curve, and the first path information is the path information corresponding to the first control information; a second acquiring unit for acquiring the correspondence between the vibration suppression parameters of the motor and the discrete points when the joint actuator runs according to the velocity curve; a determining unit for determining the position increment information corresponding to the joint target position based on the correspondence when a joint target position is received; and a control unit for controlling the motor operation based on the position increment information.

[0042] The technical solution of this invention proposes a control device for an industrial robot, which controls the operation of the motor based on position increment information, thereby suppressing the vibration of the motor and ensuring the control accuracy of the industrial robot.

[0043] In related technical solutions, calibrating the joint stiffness of industrial robots requires users to pay the robot manufacturer for expensive equipment to perform the calibration and obtain calibration parameters. However, the control method for industrial robots proposed in this invention allows the robot to directly suppress vibration by operating the aforementioned control method, eliminating the need for joint stiffness calibration and thus reducing the cost of vibration suppression.

[0044] Meanwhile, by applying the control method proposed in this invention, joint vibration can be quickly suppressed according to the on-site working conditions without waiting for manufacturer calibration, thus minimizing the impact of vibration on the operation of industrial robots.

[0045] Furthermore, the control method for industrial robots proposed in this invention eliminates the need to construct rigid-flexible dynamics models, thus reducing the workload required for industrial robots to suppress vibrations.

[0046] The technical solution of the present invention is based on the following principle: Specifically, after receiving the first control information, the calibration of the correspondence between the vibration suppression parameters of the motor and discrete points under the first path information is triggered, thereby obtaining the correspondence.

[0047] After obtaining the correspondence, the position increment information corresponding to the target position of the joint can be determined based on the correspondence, so as to control the motor operation based on the position increment information.

[0048] In some technical solutions, the joint actuator can optionally be understood as a driver used to drive the motor to rotate.

[0049] In some technical solutions, the first control information may optionally be control information or control commands for the user to initiate vibration suppression.

[0050] In some technical solutions, the first control information may optionally be the user actively activating the vibration suppression function, or the control information automatically generated by the industrial robot when the motor generates low-frequency vibrations below 20Hz.

[0051] In some technical solutions, optionally, when the industrial robot is a robotic arm, the first path information can be understood as the path planned by the controller of the robotic arm, that is, the given path.

[0052] In some technical solutions, discrete points can optionally be understood as points in the path corresponding to the first path information.

[0053] In some technical solutions, the target position of the joint can optionally be understood as the position of the link.

[0054] In some technical solutions, the position increment information can optionally be understood as the increase in the motor position.

[0055] In addition, the control device for the industrial robot proposed in this invention also has the following additional technical features.

[0056] In some technical solutions, optionally, the first path information includes multiple discrete points, and the velocity curve includes multiple sub-velocity curves corresponding one-to-one with the multiple discrete points. The second acquisition unit is specifically used to: control the joint actuator to run according to the multiple sub-velocity curves one by one until the multiple sub-velocity curves have finished running; wherein, when the joint actuator runs according to each sub-velocity curve, the following steps are performed: acquiring the vibration parameters of the motor; acquiring the quality factor corresponding to the vibration parameters; associating and storing the discrete points, vibration parameters and quality factors corresponding to the sub-velocity curves to obtain the correspondence.

[0057] In this technical solution, the first planned path is divided into multiple discrete points, and a corresponding sub-velocity curve is planned for each discrete point. This allows the joint actuator to excite low-frequency vibration of the motor when running according to the sub-velocity curve, thereby enabling the measurement of the motor's vibration parameters.

[0058] Specifically, during the process of the joint actuator running according to multiple sub-velocity curves one by one, low-frequency vibrations of the motor can be excited at each discrete point. By collecting the vibration parameters of the motor, the low-frequency vibrations can be collected and expressed using the vibration parameters. Then, the detected vibration parameters are associated with the corresponding discrete points and stored to realize the acquisition of the corresponding relationship.

[0059] In the above technical solution, by obtaining the quality factor corresponding to the vibration parameters, a physical quantity representing the damping properties of the oscillator can be used, which can also represent the magnitude of the oscillator's resonant frequency relative to the bandwidth. This facilitates the determination of position increment information based on the correspondence.

[0060] In some technical solutions, the vibration parameters optionally include a first frequency and a second frequency in the frequency domain; wherein the first frequency and the second frequency are the two frequencies with the largest amplitude in the frequency domain.

[0061] In this technical solution, by defining the vibration parameters as including a first frequency and a second frequency in the frequency domain, two vibration frequencies can be suppressed simultaneously. Using this method, for adjacent joints that are in the same direction, the vibration suppression of two joints can be simplified to the vibration suppression of the two frequencies of the joint closest to the first joint, which simplifies the adaptive vibration suppression method and improves the stability and scalability of vibration suppression.

[0062] In some technical solutions, optionally, the second acquisition unit is also used to: fit a first curve between discrete points and vibration parameters based on the correspondence; and fit a second curve between discrete points and quality factors based on the correspondence.

[0063] In this technical solution, a first curve and a second curve are obtained by fitting, so that the position increment information can be determined based on the first curve and the second curve.

[0064] In some technical solutions, optionally, the determining unit is specifically used for: obtaining a transfer function in which the motor position increment and the joint position increment are expressed in parallel; matching the target discrete point corresponding to the joint target position; determining the vibration suppression parameter corresponding to the target discrete point based on the correspondence; and determining the position increment information corresponding to the joint target position based on the transfer function and the vibration suppression parameter corresponding to the target discrete point.

[0065] In this technical solution, by obtaining the transfer function expressed in parallel form, the transfer function can be split into two parallel parts. Compared with the transfer function expressed in serial form, error amplification can be reduced, and the robustness of vibration suppression can be maximized.

[0066] Furthermore, by using a transfer function expressed in parallel, the vibration suppression parameters corresponding to the target discrete point can be applied to different frequencies, thereby achieving vibration suppression at two frequencies.

[0067] In some technical solutions, optionally, the control unit is specifically used for: acquiring first position information of the motor, the first position information being the position information of the motor at the previous moment; determining the command position information of the motor based on the position increment information and the first position information; and controlling the operation of the motor based on the command position information.

[0068] In this technical solution, the control of motor operation based on position increment information is refined. In this process, the position increment information can be superimposed on the position information of the motor at the previous moment to obtain the command position information of the motor. Then, the motor is controlled to run according to the command position information of the motor, thereby achieving vibration suppression.

[0069] During this process, the motor can continue to run as it changes over time, thereby continuously updating the first position information and position increment information, and then continuously updating the command position information of the motor to achieve continuous vibration suppression and ensure the control accuracy of the industrial robot.

[0070] According to a third aspect of the present invention, the present invention provides a control device for an industrial robot, including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described above.

[0071] According to a fourth aspect of the present invention, a readable storage medium is provided on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method as described above.

[0072] According to a fifth aspect of the present invention, an industrial robot is provided, comprising: a control device as described in any of the above-described industrial robots; and / or a readable storage medium as described above.

[0073] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0074] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0075] Figure 1 A flowchart illustrating a control method for an industrial robot according to an embodiment of the present invention is shown;

[0076] Figure 2 A schematic block diagram of an industrial robot according to an embodiment of the present invention is shown;

[0077] Figure 3 A schematic block diagram of a control device for an industrial robot according to an embodiment of the present invention is shown;

[0078] Figure 4 A schematic diagram of data processing for a vibration suppression adaptive module in an embodiment of the present invention is shown;

[0079] Figure 5 A schematic diagram of data processing for a vibration suppression module in an embodiment of the present invention is shown;

[0080] Figure 6 A schematic block diagram of a control device for another industrial robot according to an embodiment of the present invention is shown. Detailed Implementation

[0081] To better understand the above aspects, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0082] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0083] In one embodiment of this application, such as Figure 1 As shown and as Figure 2 As shown, a control method for an industrial robot is provided. The industrial robot 200 includes a joint actuator 202, a motor 204, and a link 206. The joint actuator 202 drives the motor 204 to move the link 206. The control method includes:

[0084] Step 102: Receive the first control information;

[0085] Step 104: Obtain discrete points in the first path information. The discrete points are associated with planned speed curves. The first path information is the path information corresponding to the first control information.

[0086] Step 106: Obtain the correspondence between the vibration suppression parameters of the motor and discrete points when the joint actuator runs according to the speed curve;

[0087] Step 108: Upon receiving the joint target position, determine the position increment information corresponding to the joint target position based on the correspondence relationship;

[0088] Step 110: Control the motor operation based on the position increment information.

[0089] The embodiments of the present invention propose a control method for an industrial robot. By running the above control method, the motor operation is controlled based on position increment information, which can suppress the vibration of the motor and thus ensure the control accuracy of the industrial robot.

[0090] In related embodiments, calibrating the joint stiffness of an industrial robot requires the user to pay the robot manufacturer for expensive equipment to perform the calibration and obtain calibration parameters. However, by applying the control method for industrial robots proposed in this invention, the robot can directly achieve vibration suppression by running the aforementioned control method, eliminating the need for joint stiffness calibration and thus reducing the cost of vibration suppression.

[0091] Meanwhile, the control method proposed in this invention can quickly suppress joint vibrations according to the on-site working conditions, without waiting for manufacturer calibration, thus minimizing the impact of vibrations on industrial robot operations.

[0092] Furthermore, the control method for industrial robots proposed in this invention eliminates the need to construct rigid-flexible dynamics models, thus reducing the workload required for industrial robots to suppress vibrations.

[0093] The embodiments of the present invention are implemented based on the following principle: specifically, after receiving the first control information, the calibration of the correspondence between the vibration suppression parameters of the motor and discrete points under the first path information is triggered, thereby obtaining the correspondence.

[0094] After obtaining the correspondence, the position increment information corresponding to the target position of the joint can be determined based on the correspondence, so as to control the motor operation based on the position increment information.

[0095] In some embodiments, the joint actuator can be understood as a actuator for driving the rotation of a motor.

[0096] In some embodiments, the first control information may optionally be control information or control instructions for the user to initiate vibration suppression.

[0097] In some embodiments, the first control information may optionally be the user actively activating the vibration suppression function, or the control information automatically generated by the industrial robot when the motor generates low-frequency vibrations below 20Hz.

[0098] In some embodiments, optionally, when the industrial robot is a robotic arm, the first path information can be understood as the path planned by the controller of the robotic arm, i.e., the given path.

[0099] In some embodiments, a discrete point may be understood as a point in the path corresponding to the first path information.

[0100] In some embodiments, the target joint position may be understood as the position of the link.

[0101] In some embodiments, the position increment information can optionally be understood as the amount of increase in the motor position.

[0102] In some embodiments, optionally, the first path information includes multiple discrete points, and the velocity curve includes multiple sub-velocity curves corresponding one-to-one with the multiple discrete points. Obtaining the correspondence between the vibration suppression parameters of the motor and the discrete points when the joint actuator runs according to the velocity curves specifically includes: controlling the joint actuator to run according to the multiple sub-velocity curves one by one until the multiple sub-velocity curves have finished running; wherein, when the joint actuator runs according to each sub-velocity curve, the following steps are performed: obtaining the vibration parameters of the motor; obtaining the quality factor corresponding to the vibration parameters; associating and storing the discrete points, vibration parameters and quality factors corresponding to the sub-velocity curves to obtain the correspondence.

[0103] In this embodiment, the first planned path is divided into multiple discrete points, and a corresponding sub-velocity curve is planned for each discrete point so that the joint actuator can excite the low-frequency vibration of the motor when running according to the sub-velocity curve, thereby realizing the measurement of the vibration parameters of the motor.

[0104] Specifically, during the process of the joint actuator running according to multiple sub-velocity curves one by one, low-frequency vibrations of the motor can be excited at each discrete point. By collecting the vibration parameters of the motor, the low-frequency vibrations can be collected and expressed using the vibration parameters. Then, the detected vibration parameters are associated with the corresponding discrete points and stored to realize the acquisition of the corresponding relationship.

[0105] In the above embodiments, by obtaining the quality factor corresponding to the vibration parameters, a physical quantity representing the damping properties of the oscillator can be used, which can also represent the magnitude of the oscillator's resonant frequency relative to the bandwidth. This facilitates the determination of position increment information based on the correspondence.

[0106] In some embodiments, the vibration parameters may optionally include a first frequency and a second frequency in the frequency domain; wherein the first frequency and the second frequency are the two frequencies with the largest amplitudes in the frequency domain.

[0107] In this embodiment, by defining the vibration parameters as including a first frequency and a second frequency in the frequency domain, two vibration frequencies can be suppressed simultaneously. Using this method, for adjacent joints in the same direction, the vibration suppression of two joints can be simplified to the vibration suppression of the two frequencies of the joint closest to the first joint, which simplifies the adaptive vibration suppression method and improves the stability and scalability of vibration suppression.

[0108] In some embodiments, the control method may optionally further include: fitting a first curve between discrete points and vibration parameters based on a correspondence; and fitting a second curve between discrete points and quality factors based on a correspondence.

[0109] In this embodiment, a first curve and a second curve are obtained by fitting, so that position increment information can be determined based on the first curve and the second curve.

[0110] In some embodiments, optionally, upon receiving the joint target position, determining the position increment information corresponding to the joint target position based on the correspondence relationship specifically includes: obtaining a transfer function that expresses the motor position increment and the joint position increment in parallel; matching the target discrete point corresponding to the joint target position; determining the vibration suppression parameter corresponding to the target discrete point based on the correspondence relationship; and determining the position increment information corresponding to the joint target position based on the transfer function and the vibration suppression parameter corresponding to the target discrete point.

[0111] In this embodiment, by obtaining the transfer function expressed in parallel form, the transfer function can be split into two parallel parts. Compared with the transfer function expressed in serial form, error amplification can be reduced, and the robustness of vibration suppression can be maximized.

[0112] Furthermore, by using a transfer function expressed in parallel, the vibration suppression parameters corresponding to the target discrete point can be applied to different frequencies, thereby achieving vibration suppression at two frequencies.

[0113] In some embodiments, optionally, controlling the motor operation based on position increment information specifically includes: acquiring first position information of the motor, the first position information being the position information of the motor at the previous moment; determining command position information of the motor based on the position increment information and the first position information; and controlling the motor operation based on the command position information.

[0114] In this embodiment, the control of motor operation based on position increment information is refined. In this process, the position increment information can be superimposed on the motor position information of the previous moment to obtain the command position information of the motor. Then, the motor is controlled to run according to the command position information of the motor, thereby achieving vibration suppression.

[0115] During this process, the motor can continue to run as it changes over time, thereby continuously updating the first position information and position increment information, and then continuously updating the command position information of the motor to achieve continuous vibration suppression and ensure the control accuracy of the industrial robot.

[0116] In one embodiment, such as Figure 3 As shown, the present invention provides a control device 300 for an industrial robot. The industrial robot includes a joint actuator, a motor, and a link. The joint actuator drives the motor to move the link. The control device includes: a receiving unit 302 for receiving first control information; a first acquisition unit 304 for acquiring discrete points in first path information, wherein the discrete points are associated with a planned velocity curve, and the first path information is the path information corresponding to the first control information; a second acquisition unit 306 for acquiring the correspondence between the vibration suppression parameters of the motor and the discrete points when the joint actuator runs according to the velocity curve; a determining unit 308 for determining the position increment information corresponding to the joint target position based on the correspondence when the joint target position is received; and a control unit 310 for controlling the motor operation based on the position increment information.

[0117] The embodiments of the present invention propose a control device 300 for an industrial robot, which controls the operation of the motor based on position increment information, thereby suppressing the vibration of the motor and ensuring the control accuracy of the industrial robot.

[0118] In related embodiments, calibrating the joint stiffness of an industrial robot requires the user to pay the robot manufacturer for expensive equipment to perform the calibration and obtain calibration parameters. However, by applying the control method for industrial robots proposed in this invention, the robot can directly achieve vibration suppression by running the aforementioned control method, eliminating the need for joint stiffness calibration and thus reducing the cost of vibration suppression.

[0119] Meanwhile, by applying the control method proposed in this invention, joint vibration can be quickly suppressed according to the on-site working conditions without waiting for manufacturer calibration, thus minimizing the impact of vibration on the operation of industrial robots.

[0120] Furthermore, the control method for industrial robots proposed in this invention eliminates the need to construct rigid-flexible dynamics models, thus reducing the workload required for industrial robots to suppress vibrations.

[0121] The embodiments of the present invention are implemented based on the following principle: specifically, after receiving the first control information, the calibration of the correspondence between the vibration suppression parameters of the motor and discrete points under the first path information is triggered, thereby obtaining the correspondence.

[0122] After obtaining the correspondence, the position increment information corresponding to the target position of the joint can be determined based on the correspondence, so as to control the motor operation based on the position increment information.

[0123] In some embodiments, the joint actuator can be understood as a actuator for driving the rotation of a motor.

[0124] In some embodiments, the first control information may optionally be control information or control instructions for the user to initiate vibration suppression.

[0125] In some embodiments, the first control information may optionally be the user actively activating the vibration suppression function, or the control information automatically generated by the industrial robot when the motor generates low-frequency vibrations below 20Hz.

[0126] In some embodiments, optionally, when the industrial robot is a robotic arm, the first path information can be understood as the path planned by the controller of the robotic arm, i.e., the given path.

[0127] In some embodiments, a discrete point may be understood as a point in the path corresponding to the first path information.

[0128] In some embodiments, the target joint position may be understood as the position of the link.

[0129] In some embodiments, the position increment information can optionally be understood as the amount of increase in the motor position.

[0130] In some embodiments, optionally, the first path information includes multiple discrete points, and the velocity curve includes multiple sub-velocity curves corresponding one-to-one with the multiple discrete points. The second acquisition unit 306 is specifically used to: control the joint actuator to run according to the multiple sub-velocity curves one by one until the multiple sub-velocity curves have finished running; wherein, when the joint actuator runs according to each sub-velocity curve, the following steps are performed: acquiring the vibration parameters of the motor; acquiring the quality factor corresponding to the vibration parameters; associating and storing the discrete points, vibration parameters and quality factors corresponding to the sub-velocity curves to obtain the correspondence.

[0131] In this embodiment, the first planned path is divided into multiple discrete points, and a corresponding sub-velocity curve is planned for each discrete point so that the joint actuator can excite the low-frequency vibration of the motor when running according to the sub-velocity curve, thereby realizing the measurement of the vibration parameters of the motor.

[0132] Specifically, during the process of the joint actuator running according to multiple sub-velocity curves one by one, low-frequency vibrations of the motor can be excited at each discrete point. By collecting the vibration parameters of the motor, the low-frequency vibrations can be collected and expressed using the vibration parameters. Then, the detected vibration parameters are associated with the corresponding discrete points and stored to realize the acquisition of the corresponding relationship.

[0133] In the above embodiments, by obtaining the quality factor corresponding to the vibration parameters, a physical quantity representing the damping properties of the oscillator can be used, which can also represent the magnitude of the oscillator's resonant frequency relative to the bandwidth. This facilitates the determination of position increment information based on the correspondence.

[0134] In some embodiments, the vibration parameters may optionally include a first frequency and a second frequency in the frequency domain; wherein the first frequency and the second frequency are the two frequencies with the largest amplitudes in the frequency domain.

[0135] In this embodiment, by defining the vibration parameters as including a first frequency and a second frequency in the frequency domain, two vibration frequencies can be suppressed simultaneously. Using this method, for the case where adjacent joints are in the same direction, the vibration suppression of two joints can be simplified to the vibration suppression of the two frequencies of the joint closest to the first joint, which simplifies the adaptive vibration suppression method and improves the stability and scalability of vibration suppression.

[0136] In some embodiments, optionally, the second acquisition unit 306 is further configured to: fit a first curve between discrete points and vibration parameters based on the correspondence; and fit a second curve between discrete points and quality factors based on the correspondence.

[0137] In this embodiment, a first curve and a second curve are obtained by fitting, so that position increment information can be determined based on the first curve and the second curve.

[0138] In some embodiments, optionally, the determining unit 308 is specifically configured to: obtain a transfer function in which the motor position increment and the joint position increment are expressed in parallel; match a target discrete point corresponding to the joint target position; determine the vibration suppression parameter corresponding to the target discrete point based on the correspondence; and determine the position increment information corresponding to the joint target position based on the transfer function and the vibration suppression parameter corresponding to the target discrete point.

[0139] In this embodiment, by obtaining the transfer function expressed in parallel form, the transfer function can be split into two parallel parts. Compared with the transfer function expressed in serial form, error amplification can be reduced, and the robustness of vibration suppression can be maximized.

[0140] Furthermore, by using a transfer function expressed in parallel, the vibration suppression parameters corresponding to the target discrete point can be applied to different frequencies, thereby achieving vibration suppression at two frequencies.

[0141] In some embodiments, optionally, the control unit 310 is specifically configured to: acquire first position information of the motor, the first position information being the position information of the motor at the previous moment; determine command position information of the motor based on position increment information and the first position information; and control the motor to run based on the command position information.

[0142] In this embodiment, the control of motor operation based on position increment information is refined. In this process, the position increment information can be superimposed on the motor position information of the previous moment to obtain the command position information of the motor. Then, the motor is controlled to run according to the command position information of the motor, thereby achieving vibration suppression.

[0143] During this process, the motor can continue to run as it changes over time, thereby continuously updating the first position information and position increment information, and then continuously updating the command position information of the motor to achieve continuous vibration suppression and ensure the control accuracy of the industrial robot.

[0144] In one embodiment, taking a robotic arm as an example, the control device of the industrial robot is mainly divided into two modules: a vibration suppression adaptive module and a vibration suppression module.

[0145] The vibration suppression adaptive module relies on the industrial robot's controller and joint actuators to perform certain actions, creating a correspondence between vibration suppression parameters and position. The specific steps are as follows:

[0146] (1) When the user creates an execution command in the controller and the robotic arm executes the command, it is found that the joints of the robotic arm exhibit obvious low-frequency vibrations in the range below 20Hz.

[0147] (2) The user activates the adaptive vibration suppression function on the controller.

[0148] (3) Each joint of the robotic arm returns to its initial position as instructed.

[0149] (4) The controller determines the discrete points of the command path for adaptive calculation of vibration suppression parameters through calculation, and plans a T-shaped velocity curve between the discrete points.

[0150] (5) The controller sequentially executes the T-shaped velocity curve planning between discrete points. When the T-shaped velocity curve planning position point is issued, the curve of the position of the robotic arm link over time is recorded. The controller extracts the vibration suppression parameters of each discrete point based on this curve.

[0151] (6) Perform step (5) on all discrete points to obtain the relationship between vibration suppression parameters and position, and store it for use by the vibration suppression module.

[0152] (7) The robotic arm linkage returns to the initial command position.

[0153] The vibration suppression module uses an adaptive parameter table to shape the issued commands, and the steps are as follows:

[0154] (1) Determine the number of vibration frequencies that each joint needs to suppress based on the adaptive parameter table.

[0155] (2) Perform position shaping, velocity feedforward shaping and dynamic feedforward calculations on the issued position commands.

[0156] Among them, such as Figure 4 As shown, in the vibration suppression adaptive module, the motor operates in position control mode, executing the controller's path planning and trajectory planning. The controller is the central hub of the entire vibration suppression parameter adaptive module, responsible for a series of key actions such as startup, process, and data processing, and specifically includes the following functional units:

[0157] User instructions are motion commands specified by the user that cause link vibration under specific kinematic and dynamic parameters, which are also the first control information in this invention.

[0158] Adaptive vibration suppression is a flag that determines whether the adaptive vibration function can be activated through a series of actions, including user activation and internal command checks.

[0159] Command decomposition: Once the controller confirms that adaptive vibration can be initiated, it interprets the user command and, according to specific rules such as joint reversal and distance discretization, determines discrete points on the specified path (i.e., the first path information). Inverse kinematics is performed on these discrete points to obtain the joint values ​​at the discrete path points. T-shaped velocity planning in joint space is then performed between these discrete points, thus decomposing the user command, such as commands in the operating space or potentially the joint space, into a series of T-shaped velocity plans in joint space, which are then sequentially sent to the joint actuators for execution. Here, t represents time and v represents velocity.

[0160] The data receiving and processing module controls the start and stop of data reception and performs a series of non-delayed optimal data filtering operations. The controller issues a T-shaped speed plan and simultaneously activates the data receiving and processing module, ensuring that it begins acquiring the motor's position before the motor executes the command. After the T-shaped speed plan is issued, the data receiving and processing module checks if the motor is in position; when vibration stops and the motor is in position, data reception ceases. The data receiving and processing module performs non-delayed filtering on the received data, removing white noise and high-frequency noise. Finally, a time-domain dataset corresponding to the current T-shaped speed plan is obtained.

[0161] The Fast Fourier Transform (FFT) module completes the conversion of the time-domain data obtained from the data processing module to the frequency domain.

[0162] The parameter table module primarily performs frequency domain data inspection on the FFT, extracting the two frequencies f1 and f2 with the largest amplitudes, which are the first and second frequencies in this invention. It then calculates the corresponding Q1 and Q2 from the frequency domain data, which are the first and second quality factors in this invention, and forms a data pair (s) with the current path point. i ,f i1 ,f i2 Q i1 Q i2 ), and save it.

[0163] Among them, s i Let f represent the i-th discrete point. i1 f represents the first frequency corresponding to the i-th discrete point. i2 Q represents the second frequency corresponding to the i-th discrete point. i1 Let Q represent the first quality factor corresponding to the i-th discrete point. i2 This represents the second quality factor corresponding to the i-th discrete point.

[0164] Repeat the above steps until all T-shaped planning is completed, obtaining data pairs at different path points. Through data fitting, construct s-f1, s-f2, s-Q1, and s-Q2 curves, which will serve as parameter inputs for the vibration suppression module.

[0165] Among them, s-f1 and s-f2 are the first curves in this invention, and s-Q1 and s-Q2 are the second curves in this invention.

[0166] like Figure 5 As shown, the vibration suppression module includes a position shaping function module, a position command module, a velocity feedforward module, and a torque feedforward calculation function module.

[0167] Among them, position shaping is the main functional module of the vibration suppression module, specifically:

[0168] τ is the output torque of the motor, θ is the motor position, and q is the connecting rod position. Therefore, according to the two-inertia system, we have the following formula:

[0169]

[0170]

[0171]

[0172] in, It is the derivative of θ with respect to time. J is the derivative of q with respect to time. m For the inertia of the motor, w a ,ξ a ,w r ,ξ r These are the anti-resonance frequency, anti-resonance damping coefficient, resonance frequency, and resonance damping coefficient, respectively, which include the dynamic parameters of the load. s is the Laplace operator, · is the dot product symbol, Δθ is the change in θ, and Δq is the change in q.

[0173] Equation (3) can be extended to a three-inertia system, applicable to the case with two resonance points, i.e.:

[0174]

[0175] Where, ξ a1 ξ is the anti-resonance damping coefficient corresponding to the first resonance point. a2 It is the anti-resonance damping coefficient corresponding to the second resonance point, w a1 It is the anti-resonance frequency corresponding to the first resonance point, w a2 It is the anti-resonance frequency corresponding to the second resonance point, and s is the Laplace operator.

[0176] Formula (4) is equivalent to:

[0177]

[0178] Among them, the advantage of formula (5) over formula (4) is that it transforms the original series transfer function into a parallel form, decouples the two frequencies, and adds a coupling term.

[0179] Specifically, the transfer functions shown in formula (5) are all non-causal. In practical applications, to achieve stability, it is necessary to add a filter. Assume the filter bandwidth is w. c Its value depends on the joint bandwidth, which means that determining the joint bandwidth determines the bandwidth of subsequent data processing. Therefore, s in formula (5) 2 Rewritten as:

[0180]

[0181] Where ξ is the damping coefficient, s is the Laplace operator, and w is the frequency.

[0182] The decoupling of position shaping can be achieved based on formulas (5) and (6).

[0183] The location planning module performs real-time interpolation for path planning and velocity planning, and outputs the target position of the joint.

[0184] The joint bandwidth is a value selected based on the actual situation. Users can specify it, and it is generally set to be 20Hz to 30Hz higher than the system maximum to ensure that low-frequency vibration frequencies can be observed, while also ensuring that the bandwidth of the controller is within the specified range.

[0185] The bandwidth limiting module limits high frequencies based on the set joint bandwidth value, which has a certain smoothing effect on the interpolation trajectory. The bandwidth limiting module can be an Infinite Impulse Response (IIR) digital filter, a Finite Impulse Response (FIR) filter, or a control closed loop based on bandwidth control.

[0186] Specifically, the following formula applies to each calculation cycle:

[0187]

[0188] w=2πf (8)

[0189] In this context, Q refers to Q1 and Q2 mentioned earlier, f refers to f1 and f2 mentioned earlier, π is the symbol for pi, ξ is the damping coefficient, and w is the frequency.

[0190] Because of the smoothness and continuity of f and Q for discrete points of the path parameters, position shaping can work stably.

[0191] The motor output increment is calculated according to formula (5) and divided by the calculation period T. s The speed feedforward is obtained, and the motor's position value at the previous moment is superimposed to obtain the motor's position command.

[0192] Among them, z -1 Indicates the previous moment.

[0193] The torque feedforward module calculates the torque feedforward of the motor based on the rigid body dynamics of the robotic arm and the inertia of the motor.

[0194] In one embodiment, such as Figure 6 As shown, the present invention provides a control device 600 for an industrial robot, including a processor 602 and a memory 604. The memory 604 stores programs or instructions that can run on the processor 602. When the program or instructions are executed by the processor, they implement the steps of any of the methods described above.

[0195] The memory 604 can be used to store software programs and various data. The memory 604 mainly includes a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area can store the operating system, application programs or instructions required for at least one function (such as sound playback function, image playback function, etc.). Furthermore, the memory 604 can include volatile memory or non-volatile memory, or both. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DRRAM). The memory in the embodiments of this application includes, but is not limited to, these and any other suitable types of memory.

[0196] In one embodiment, the present invention provides a readable storage medium on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method as described above.

[0197] In one embodiment, the present invention provides an industrial robot, including: a control device as described in any of the above industrial robots; and / or a readable storage medium as described in the above.

[0198] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the textual description of this invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0199] In the textual description of this invention, it is understood that, unless explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0200] In the claims, description, and accompanying drawings of this invention, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In the claims, description, and accompanying drawings of this invention, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0201] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for an industrial robot, characterized in that, The industrial robot includes a joint actuator, a motor, and a linkage. The joint actuator drives the motor to move the linkage. The control method includes: Receive first control information; Obtain discrete points in the first path information, wherein the discrete points are associated with a planned speed curve, and the first path information is the path information corresponding to the first control information; Obtain the correspondence between the vibration suppression parameters of the motor and the discrete points when the joint actuator operates according to the speed curve; Upon receiving the target joint position, the position increment information corresponding to the target joint position is determined based on the correspondence, wherein the position increment information is the increase in the motor position; The motor is controlled to operate based on the incremental position information. The control of the motor operation based on the position increment information specifically includes: Obtain the first position information of the motor, where the first position information is the position information of the motor at the previous moment; The command position information of the motor is determined based on the position increment information and the first position information; The motor is controlled to operate based on the command location information; Upon receiving the joint target position, determining the position increment information corresponding to the joint target position based on the correspondence specifically includes: Obtain the transfer function that expresses the motor position increment and joint position increment in parallel; Match the discrete target points corresponding to the joint target positions; Based on the correspondence, the vibration suppression parameters corresponding to the target discrete point are determined; Based on the transfer function and the vibration suppression parameters corresponding to the target discrete point, the position increment information corresponding to the joint target position is determined.

2. The control method for an industrial robot according to claim 1, characterized in that, The first path information includes multiple discrete points, and the velocity curve includes multiple sub-velocity curves corresponding one-to-one with the multiple discrete points. The step of obtaining the correspondence between the vibration suppression parameters of the motor and the discrete points when the joint actuator operates according to the velocity curve specifically includes: The joint actuator is controlled to run according to the multiple sub-speed curves one by one until the multiple sub-speed curves have finished running; When the joint actuator operates according to each sub-velocity curve, the following steps are performed: Obtain the vibration parameters of the motor; Obtain the quality factor corresponding to the vibration parameters; The discrete points corresponding to the sub-velocity curves, the vibration parameters, and the quality factor are associated and stored to obtain the correspondence.

3. The control method for an industrial robot according to claim 2, characterized in that, The vibration parameters include a first frequency and a second frequency in the frequency domain; The first frequency and the second frequency are the two frequencies with the largest amplitude in the frequency domain.

4. The control method for an industrial robot according to claim 2, characterized in that, The control method further includes: Based on the correspondence, a first curve is fitted between the discrete points and the vibration parameters; Based on the correspondence, a second curve is fitted between the discrete point and the quality factor.

5. A control device for an industrial robot, characterized in that, The industrial robot includes a joint actuator, a motor, and a linkage. The joint actuator drives the motor to move the linkage. The control device includes: The receiving unit is used to receive the first control information; The first acquisition unit is used to acquire discrete points in the first path information, wherein the discrete points are associated with a planned speed curve, and the first path information is the path information corresponding to the first control information. The second acquisition unit is used to acquire the correspondence between the vibration suppression parameters of the motor and the discrete points when the joint actuator runs according to the speed curve; The determining unit is configured to, upon receiving a joint target position, determine position increment information corresponding to the joint target position based on the correspondence, wherein the position increment information is the increase in motor position; The control unit is used to control the operation of the motor based on the position increment information; The control unit is specifically used to acquire first position information of the motor, which is the position information of the motor at the previous moment; determine command position information of the motor based on the position increment information and the first position information; and control the operation of the motor based on the command position information. The determining unit is specifically used to obtain a transfer function that expresses the motor position increment and the joint position increment in parallel; match the target discrete point corresponding to the target joint position; determine the vibration suppression parameter corresponding to the target discrete point based on the correspondence; and determine the position increment information corresponding to the target joint position based on the transfer function and the vibration suppression parameter corresponding to the target discrete point.

6. A control device for an industrial robot, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the method as described in any one of claims 1 to 4.

7. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the method as described in any one of claims 1 to 4.

8. An industrial robot, characterized in that, include: The control device for an industrial robot as described in claim 5 or 6; and / or The readable storage medium as described in claim 7.

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