A collaborative control method and system for industrial robots and snake arms

Abstract

This invention relates to the field of robot control technology, specifically to a method and system for collaborative control of an industrial robot and a snake-like arm. The method includes the following steps: planning the trajectory path and generating relevant instructions based on the target trajectory and the read position and posture; issuing the corresponding instructions using TCP / IP and IO transmission methods respectively, thereby controlling the snake-like arm to move independently, and the industrial robot to move independently or simultaneously in real time. The purpose of this method and system for collaborative control of an industrial robot and a snake-like arm is to solve the problem of achieving high-precision real-time collaborative motion between two heterogeneous systems: an industrial robot and a snake-like arm.

Description

Technical Field

[0001] This invention relates to the field of robot control technology, specifically to a collaborative control method and system for an industrial robot and a snake arm. Background Technology

[0002] With the advancement of science and technology, robots are playing an increasingly important role in modern industrial production. Six-axis industrial robots are widely used in industrial production. However, as the complexity of industrial operations, the specificity of scenarios, and the scale of operations increase, six-axis industrial robots can meet most application needs in open work areas, but they are difficult to adapt to narrow and complex working environments. Snake-arm systems can achieve multi-angle bending while possessing lightweight structural advantages, but their working space is limited. Compared to single-robot systems, heterogeneous systems composed of industrial robots and snake-arm systems (such as...) Figure 1 (As shown) can facilitate the completion of the task.

[0003] Currently, my country has conducted relatively in-depth research on snake-arm robots, mainly focusing on theoretical research and snake-arm motion control technology. However, research on their collaborative motion with heterogeneous systems such as industrial robots in specific complex environments to achieve operational tasks has not yet been reported. In complex environments, the collaborative control of industrial robots and snake-arm robots directly affects whether the target task can be completed.

[0004] Currently, the most commonly used robot collaborative control methods involve collaborative control of robots from the same manufacturer using the same control system. For special application robots, especially snake-arm robots and industrial robots in heterogeneous systems, there is no publicly available collaborative control method.

[0005] Therefore, the inventors provide a method and system for the collaborative control of an industrial robot and a snake arm. Summary of the Invention

[0006] (1) Technical problems to be solved

[0007] This invention provides a method and system for collaborative control of an industrial robot and a snake arm, which solves the technical problem of achieving high-precision real-time collaborative motion between two heterogeneous systems, an industrial robot and a snake arm.

[0008] (2) Technical solution

[0009] The first aspect of the present invention provides a method for collaborative control of an industrial robot and a snake arm, comprising the following steps:

[0010] Based on the target trajectory and the read position and attitude, the trajectory path is planned and relevant instructions are generated;

[0011] The corresponding instructions are issued using TCP / IP and IO transmission methods to control the snake arm to move alone or the industrial robot to move alone or simultaneously in real time.

[0012] Furthermore, the step of planning the trajectory path and generating relevant instructions based on the target trajectory and the read position and attitude is as follows:

[0013] Based on the current pose, target trajectory, and workspace of the industrial robot and the snake arm, trajectory planning and trajectory discretization are performed, and the relevant instructions are generated.

[0014] Furthermore, the trajectory planning and discretization based on the current pose, target trajectory, and pose and workspace of the industrial robot and the snake arm specifically includes:

[0015] The trajectory of the snake arm end is discretized at a set interval, and then constraints are applied to the industrial robot based on the trajectory points to decompose the motion task to reach each trajectory point.

[0016] Furthermore, the specific steps of issuing the corresponding instructions using TCP / IP transmission mode and IO transmission mode are as follows:

[0017] The host computer sequentially sends trajectory points and collaborative control instructions to the robot controller and the multi-axis motion controller, and stores the relevant instructions in the cache area, waiting for subsequent instructions; wherein, the robot controller only caches the relevant trajectory of the industrial robot sent by the TCP / IP transmission method, and the multi-axis motion controller caches all control instructions and snake arm trajectory data sent by the IO transmission method.

[0018] Furthermore, when the snake-like arm moves simultaneously with the industrial robot, specifically:

[0019] After the end effector of the industrial robot reaches the trajectory point, it sends a signal to the PLC in real time through the IO transmission method. When the end effector of the snake arm reaches the trajectory point, it triggers a signal to the PLC. The PLC starts timing when it receives either of the arrival signals and ends timing when the other signal arrives or when the timeout occurs.

[0020] Furthermore, the real-time control of the snake arm's individual movement, and the industrial robot's individual or simultaneous movement, specifically refers to:

[0021] The host computer sends a start execution command to the multi-axis motion controller, which then controls the snake arm to move alone, the industrial robot to move alone, or both to move simultaneously, in real time according to the set cooperative control commands.

[0022] Furthermore, the relevant instructions include trajectory points, speed, time, and collaborative control instructions for offline and decomposed trajectories.

[0023] Furthermore, the trajectory point refers to the coordinates and orientation in the coordinate system of the industrial robot equipment.

[0024] A second aspect of the present invention provides a collaborative control system applied to the above-described collaborative control method of industrial robot and snake arm, comprising:

[0025] Industrial robots, robot controllers, snake arms, multi-axis motion controllers and host computers;

[0026] The snake-shaped arm is installed at the end of the industrial robot. The host computer communicates with the industrial robot and the multi-axis motion controller based on TCP / IP. The industrial robot communicates with the multi-axis motion controller in real time via I / O, and the industrial robot communicates with the robot controller in real time via I / O.

[0027] Furthermore, the collaborative control system also includes a PLC, through which the multi-axis motion controller issues real-time commands to the industrial robot.

[0028] (3) Beneficial effects

[0029] In summary, this invention solves the problem of difficult online collaborative motion between two heterogeneous systems, a snake arm and an industrial robot without a real-time bus interface, by combining real-time I / O with TCP / IP. It simplifies the complexity of the communication interface and shortens the development cycle. Compared with the traditional method of converting trajectory points into robot programs for import, it is more convenient. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a structure for the collaborative installation of an industrial robot and a snake-like arm.

[0032] Figure 2 This is a flowchart illustrating a collaborative control method for an industrial robot and a snake arm provided in an embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram of a specific process for a collaborative control method between an industrial robot and a snake arm provided in an embodiment of the present invention;

[0034] Figure 4 This is a flowchart illustrating the collaborative motion process of an industrial robot and a snake arm, as provided in an embodiment of the present invention.

[0035] Figure 5 This is a schematic diagram of the structure of a collaborative control system for an industrial robot and a snake arm provided in an embodiment of the present invention.

[0036] In the picture:

[0037] 1-Industrial robot; 2-Snake arm. Detailed Implementation

[0038] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. That is, the present invention is not limited to the described embodiments, and any modifications, substitutions and improvements to the parts, components and connection methods are covered without departing from the spirit of the present invention.

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "install" 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 direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] Currently, collaborative control between heterogeneous systems often employs a single TCP / IP bus, bus message, or IO control, which suffers from a lack of diversity and makes it difficult to achieve high-precision real-time collaboration for industrial robots without external real-time bus interfaces.

[0043] Figure 2 This is a flowchart illustrating a collaborative control method for an industrial robot and a snake arm provided in an embodiment of the present invention, as shown below. Figure 2As shown, the method may include the following steps:

[0044] S100. Based on the target trajectory and the read position and attitude, plan the trajectory path and generate relevant instructions;

[0045] The S200 uses TCP / IP and IO transmission methods to issue corresponding instructions to control the snake arm to move individually or the industrial robot to move individually or simultaneously in real time.

[0046] In the above embodiments, the industrial robot and the snake arm's multi-axis motion controller are computing systems composed of different types of computer hardware or software. They come from different manufacturers, use different operating systems, programming languages, and protocols. Their collaborative control belongs to the control of heterogeneous systems, requiring specific protocols or interfaces for communication and collaboration. For the integrated control of this system, since the industrial robot needs to move collaboratively with the snake arm, it has requirements for the motion trajectory. The motion trajectory of the snake arm's end effector is a synthesis of the motion trajectories of the industrial robot and the snake arm. Therefore, the synchronization of their movements must be ensured during the movement. For the snake arm, its movement is directly controlled by the multi-axis motion controller, so there is no delay problem. For the industrial robot, the manufacturer provides a TCP / IP protocol communication interface and a limited number of real-time I / O signal interfaces. The real-time performance of TCP / IP communication in industrial control cannot be guaranteed, and using real-time I / O signal interfaces for all data transmission would require an enormous number of I / O signal interfaces (on the order of thousands). Therefore, TCP / IP is used to transmit the position and other information that the industrial robot needs to execute, while real-time I / O is used to transmit motion commands and feedback information with high real-time requirements.

[0047] As an optional implementation, in step S100, the trajectory path is planned and relevant instructions are generated based on the target trajectory and the read position and attitude, specifically as follows:

[0048] Based on the current pose, target trajectory, and pose and workspace of the industrial robot and snake arm, trajectory planning and trajectory discretization are performed, and relevant instructions are generated.

[0049] As an optional implementation, in step S200, trajectory planning and trajectory discretization are performed based on the current pose, target trajectory, pose, and workspace of the industrial robot and the snake arm. Specifically, the trajectory of the snake arm end is discretized according to a set interval, and then constraints are applied to the industrial robot according to the trajectory points to decompose the motion task to reach each trajectory point.

[0050] As an optional implementation, in step S200, corresponding instructions are issued using TCP / IP transmission mode and IO transmission mode respectively, specifically as follows:

[0051] The host computer sequentially sends trajectory points and collaborative control instructions to the robot controller and multi-axis motion controller, and stores the relevant instructions in the cache area, waiting for subsequent instructions. Among them, the robot controller only caches the relevant trajectory of the industrial robot sent via TCP / IP transmission, while the multi-axis motion controller caches all control instructions and snake arm trajectory data sent via IO transmission.

[0052] It's important to note that using a combination of TCP / IP communication and real-time I / O for transmission first requires addressing the coordination between TCP / IP transmission and I / O commands in industrial robots. This can be solved using caching. Commands generated offline can be sent via TCP / IP, with N commands sent at a time. When executing N-5 commands, if subsequent commands are still pending, they can be sent again until all commands have been transmitted.

[0053] By transmitting trajectory points via TCP / IP, using the controller as a buffer, and employing PLC / IO communication for real-time control commands and position signals, the continuity of the snake arm and the industrial robot's trajectory is ensured, as well as the synchronization of their coordinated movements.

[0054] The specific instructions are as follows:

[0055] The first line indicates a wait for a motion command; if this command is 0, the industrial robot will not move.

[0056] Command to move to a certain position;

[0057] Send an I / O signal to the PLC to indicate that the motion is complete;

[0058] Command to move to a certain position;

[0059] Send an I / O signal to the PLC to indicate that the motion is complete;

[0060] …

[0061] Finish.

[0062] As an optional implementation, real-time control can be used to move the snake arm individually, or to move the industrial robot individually or simultaneously, such as... Figure 3 As shown, specifically: the host computer sends a start execution command to the multi-axis motion controller, which then controls the snake arm to move alone, the industrial robot to move alone, or both to move simultaneously, in real time according to the set collaborative control commands.

[0063] As an optional implementation, when the snake arm moves simultaneously with the industrial robot, such as Figure 4As shown, specifically: after the end effector of the industrial robot reaches the trajectory point, it sends a signal to the PLC in real time via IO transmission. After the end effector of the snake arm reaches the trajectory point, it triggers a signal to the PLC. The PLC starts timing when it receives either of the arrival signals and ends timing when the other signal arrives or when the timeout occurs.

[0064] As an optional implementation, the relevant instructions include trajectory points, speed, time, and cooperative control instructions for offline trajectory and decomposed trajectory.

[0065] As an optional implementation, the trajectory point is the coordinate and orientation in the coordinate system of the industrial robot equipment.

[0066] Figure 5 This is a schematic diagram of the structure of a collaborative control system applied to the above-described collaborative control method of industrial robot and snake arm, provided by the second aspect of the present invention. Figure 5 As shown, the collaborative control system may include:

[0067] Industrial robots, robot controllers, snake arms, multi-axis motion controllers and host computers;

[0068] The snake arm is installed at the end of the industrial robot. The host computer communicates with the industrial robot and the multi-axis motion controller via TCP / IP. The industrial robot communicates with the multi-axis motion controller via real-time IO communication, and the industrial robot communicates with the robot controller via real-time IO communication.

[0069] This system can send trajectory points to industrial robots and snake arms online, which is more convenient than the traditional method of converting trajectory points into robot programs for import.

[0070] As an optional implementation, the collaborative control system also includes a PLC, through which the multi-axis motion controller issues real-time commands to the industrial robot.

[0071] Example 1

[0072] like Figure 1 As shown, industrial robot 1 is fixed to the ground, and snake arm 2 is fixed to the flange of industrial robot 1. Industrial robot 1 and snake arm 2 move in coordination, so that the end of snake arm 2 moves in a straight line in space at a target speed. A coordinate system is established with the equipment coordinate system of industrial robot 1 as the reference coordinate system. The coordinated control method includes the following steps:

[0073] Step 1: Discretization and decomposition of motion trajectory and velocity planning

[0074] First, the trajectory of the snake arm's end effector is discretized according to a fixed-interval rule, that is, the trajectory is discretized at intervals of ΔL = 0.5mm. Then, constraints are applied to the industrial robot based on the trajectory points, mainly to compensate for the insufficient motion space of the snake arm. The motion task to reach each trajectory point is decomposed, where the trajectory points of the industrial robot are the coordinates and orientations in the industrial robot equipment coordinate system, and the trajectory points of the snake arm are...

[0075] The movement speed v of the industrial robot is planned based on the set movement time Δt = 100ms of the snake arm, v = ΔL / Δt = 5mm / s.

[0076] Step 2: Issuance and caching of motion trajectory points and coordination commands

[0077] The host computer sends the trajectory points, speed, time, and collaborative control instructions obtained from the offline and decomposed trajectory in step 1 to the industrial robot and the multi-axis motion controller, respectively. The industrial robot controller and the multi-axis motion controller store the path and collaborative instructions in the buffer area, waiting for the next instruction.

[0078] Step 3: Synchronize the start time of exercise

[0079] The host computer sends a start execution command to the multi-axis motion controller, which then controls the snake arm to move alone, the industrial robot to move alone, or both to move simultaneously, in real time according to the set collaborative commands. The collaborative commands are sent to the industrial robot by the multi-axis motion controller through real-time I / O.

[0080] Step 4: The industrial robot and the snake arm receive control commands and execute corresponding actions according to the commands sent by the multi-axis motion controller. The snake arm controller runs directly in the multi-axis motion controller, which sends real-time commands to the industrial robot through the PLC real-time I / O.

[0081] Step 5: Coordination during the movement process

[0082] When moving together with the snake arm, the industrial robot's end effector sends a signal to the PLC via real-time I / O after reaching the trajectory point. The snake arm's end effector triggers a signal to the PLC after reaching the trajectory point. The PLC starts timing when it receives either of the arrival signals and ends timing when the other signal arrives. The interval between them is Δt1. The timing threshold is set to 18ms. If it exceeds 18ms, the timing ends and the system alarms that the synchronization time is out of tolerance. If it is within 20ms, the system will repeatedly execute steps 4 and 5 until it ends.

[0083] The format of trajectory command issued by the host computer:

[0084] Actuator + motion type + coordinates and attitude values ​​+ synchronous motion point number + motion time / speed + whether it is the final point.

[0085] The actuators include an industrial robot and a snake arm; the motion forms include point-to-point, straight line, and circular arc; the coordinates and attitude values ​​are the coordinates and attitude angles of the center point of the industrial robot flange in the industrial robot equipment coordinate system, and the coordinates and attitude of the snake arm in the snake arm equipment coordinate system; the synchronous motion point number, 0 indicates no synchronous motion, 1, 2, 3... represent the point number, and the point number corresponds one-to-one when the industrial robot and the snake arm move synchronously; the motion time refers to the time it takes for the snake arm to move to the specified coordinate, and the motion speed is the speed of the industrial robot. If it is synchronous motion, the motion speed is set according to step 1; whether the final point is an identifier bit, that is, after all points are sent, the system sends an identifier bit to start execution.

[0086] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0087] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A method for collaborative control of an industrial robot and a snake-like arm, characterized in that, The method includes the following steps: Based on the target trajectory and the read position and attitude, the trajectory path is planned and relevant instructions are generated; The corresponding instructions are issued using TCP / IP and IO transmission methods respectively to control the snake arm to move individually or the industrial robot to move individually or simultaneously in real time. The step of planning the trajectory path and generating relevant instructions based on the target trajectory and the read position and attitude is as follows: Based on the current pose, target trajectory, and pose and workspace of the industrial robot and the snake arm, trajectory planning and trajectory discretization are performed, and the relevant instructions are generated. The process of trajectory planning and discretization based on the current pose, target trajectory, and pose and workspace of the industrial robot and the snake arm specifically involves: The trajectory of the snake arm end is discretized at a set interval, and then constraints are applied to the industrial robot based on the trajectory points to decompose the motion task to reach each trajectory point.

2. The industrial robot and snake arm collaborative control method according to claim 1, characterized in that, The specific steps for issuing the relevant instructions using TCP / IP and IO transmission methods are as follows: The host computer sequentially sends trajectory points and collaborative control instructions to the robot controller and the multi-axis motion controller, and stores the relevant instructions in the cache area, waiting for subsequent instructions; wherein, the robot controller only caches the relevant trajectory of the industrial robot sent by the TCP / IP transmission method, and the multi-axis motion controller caches all control instructions and snake arm trajectory data sent by the IO transmission method.

3. The industrial robot and snake arm collaborative control method according to claim 1, characterized in that, When the snake-like arm and the industrial robot move simultaneously, specifically: After the end effector of the industrial robot reaches the trajectory point, it sends a signal to the PLC in real time through the IO transmission method. When the end effector of the snake arm reaches the trajectory point, it triggers a signal to the PLC. The PLC starts timing when it receives either of the arrival signals and ends timing when the other signal arrives or when the timeout occurs.

4. The industrial robot and snake arm collaborative control method according to claim 1, characterized in that, The real-time control of the snake arm's individual movement and the industrial robot's individual or simultaneous movement specifically includes: The host computer sends a start execution command to the multi-axis motion controller, which then controls the snake arm to move alone, the industrial robot to move alone, or both to move simultaneously, in real time according to the set cooperative control commands.

5. The industrial robot and snake arm collaborative control method according to claim 1, characterized in that, The relevant instructions include offline trajectory points, speed, time, and collaborative control instructions.

6. The industrial robot and snake arm collaborative control method according to claim 5, characterized in that, The trajectory points are the coordinates and orientations of the industrial robot equipment in the coordinate system.

7. A collaborative control system applied to the collaborative control method of an industrial robot and a snake arm as described in any one of claims 1-6, characterized in that, include: Industrial robots, robot controllers, snake arms, multi-axis motion controllers and host computers; The snake-shaped arm is installed at the end of the industrial robot. The host computer communicates with the industrial robot and the multi-axis motion controller based on TCP / IP. The industrial robot communicates with the multi-axis motion controller in real time via I / O, and the industrial robot communicates with the robot controller in real time via I / O.

8. The industrial robot and snake arm collaborative control system according to claim 7, characterized in that, It also includes a PLC, through which the multi-axis motion controller issues real-time commands to the industrial robot.

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