A rope-tethered parallel robot control method, system, apparatus, and medium

Abstract

This application discloses a control method, system, device, and storage medium for a rope-driven parallel robot, used to control eight motors of the robot. For any target motor, the control method includes: acquiring the current position of the target motor; the target motor being the first motor to move; controlling the target motor to move at a first speed; and adjusting the first speed to a second speed when the distance difference between the current position and a preset target position is less than or equal to a first preset threshold; wherein the second speed is less than the first speed. This method can reduce the motion stuttering and unevenness of rope-driven parallel robots. This application can be widely applied in the field of rope-driven parallel robot technology.

Description

Technical Field

[0001] This application relates to the field of rope-driven parallel robot technology, and in particular to a control method, system, device and storage medium for a rope-driven parallel robot. Background Technology

[0002] Cable-driven parallel robots are used in large workspaces and at high speeds. The quality and elasticity of the cables must be considered for accurate analysis of kinematics, dynamics, workspace, trajectory planning, and control. Motors are connected to multiple elastic ropes, and their operation is controlled by motors controlling these ropes. Trajectory planning refers to planning the running path, speed, and tension of the motors and traction ropes. The motors are pulled by multiple ropes, working together to control their operation. Each rope is controlled by its own motor. Although each motor has encoder feedback, the driver components may have certain differences and uncertainties, leading to variations in command execution time and motor response time. Therefore, during control, multiple motors may not simultaneously reach the target position accurately, resulting in stuttering or uneven movement before and after reaching any target point. Thus, there are still technical problems that need to be solved in this field. Summary of the Invention

[0003] The purpose of this application is to at least partially solve one of the technical problems existing in the prior art.

[0004] Therefore, one objective of this application is to provide a control method, system, device, and storage medium for a rope-driven parallel robot, which can reduce motion jamming and sluggishness in rope-driven parallel robots.

[0005] To achieve the aforementioned technical objectives, the technical solution adopted in this application includes: a rope-driven parallel robot control method for controlling eight motors of the rope-driven parallel robot. For any target motor, the control method includes:

[0006] Obtain the current position of the target motor; the target motor is the motor that moves first.

[0007] The target motor is controlled to move at a first speed. When the distance difference between the current position and the preset target position is less than or equal to a first preset threshold, the first speed is adjusted to a second speed, wherein the second speed is less than the first speed.

[0008] In addition, the method for controlling a rope-driven parallel robot according to the above embodiments of the present invention may also have the following additional technical features:

[0009] Furthermore, in this embodiment of the application, the control method further includes: when the distance difference between the current position of the target motor and the target position is greater than a first preset threshold, controlling the motor to move at the first speed.

[0010] Furthermore, in this embodiment of the application, the first speed and the second speed satisfy the following relationship:

[0011] V1 = V0 / N;

[0012] Where V1 is the second velocity, V0 is the first velocity, and N is 2≤N≤10, where N is an integer.

[0013] Furthermore, in this embodiment of the application, the step of adjusting the first speed to the second speed when the distance difference between the current position and the preset target position is less than or equal to the first preset threshold specifically includes: for any one of the target motors, when the distance difference between the current position of the motor movement and the preset target position is less than or equal to the first preset threshold, adjusting the speed of the target motor from the first speed to the second speed, and controlling the motor with the second speed until the positions of the other seven motors reach the first preset position.

[0014] Furthermore, in this embodiment of the application, the control method further includes: when the distance difference between the position of any one of the target motors and the target position is less than or equal to a first preset threshold, and the distance difference between the positions of the other seven motors and the second preset position is less than or equal to the second preset threshold, controlling all eight motors to move at a third speed.

[0015] Furthermore, in this embodiment of the application, the third speed is greater than the second speed.

[0016] On the other hand, this application embodiment also provides a rope-traction parallel robot control system for controlling eight motors of a rope-traction parallel robot. The system includes: an acquisition unit for acquiring the current position of a target motor; and a first control unit for controlling the target motor to move at a first speed. When the distance difference between the current position and a preset target position is less than or equal to a first preset threshold, the first speed is adjusted to a second speed; wherein the second speed is less than the first speed.

[0017] Furthermore, in this embodiment of the application, the system further includes a second control unit, used to control the motor to move at the first speed when the distance difference between the current position and the preset target position is greater than a first preset threshold.

[0018] On the other hand, this application also provides a rope-traction parallel robot control device, comprising:

[0019] At least one processor;

[0020] At least one memory for storing at least one program;

[0021] When the at least one program is executed by the at least one processor, the at least one processor implements a rope-driven parallel robot control method as described in any one of the inventions.

[0022] In addition, this application also provides a storage medium storing processor-executable instructions, which, when executed by a processor, are used to perform a rope-traction parallel robot control method as described in any of the preceding claims.

[0023] The advantages and beneficial effects of this application 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 this application:

[0024] This application can obtain the current position of the target motor that moves first among eight motors; and control the target motor to move at a first speed. When the distance difference between the current position of the target motor and the target position is less than or equal to a first preset threshold, this application can adjust the first speed to a second speed that is less than the first speed. This allows the position between the target motor and the other seven motors to be continuously reduced before reaching the target position, thereby improving the phenomenon of motion stuttering and sluggishness among the eight motors. Attached Figure Description

[0025] Figure 1 This is a structural schematic diagram of a rope-driven parallel robot in the prior art;

[0026] Figure 2 This is a schematic diagram of a structure for trajectory generation in a rope-driven parallel robot in the prior art.

[0027] Figure 3 This is a schematic diagram illustrating the steps of a rope-driven parallel robot control method in a specific embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the steps of a rope-traction parallel robot control method in another specific embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of a rope-traction parallel robot control system in a specific embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of a rope-traction parallel robot control device in a specific embodiment of the present invention. Detailed Implementation

[0031] The following detailed description, in conjunction with the accompanying drawings, illustrates the principles and processes of the rope-traction parallel robot control method, system, device, and storage medium according to embodiments of the present invention.

[0032] Cable-driven parallel robots, using ropes as transmission elements, are flexible parallel robots mainly composed of components such as a frame, pulleys, drive motors, ropes, and end effectors. Figure 1 As shown, the end effector is located at the center of the frame. The end effector is directly controlled by eight cables, which are in turn driven and controlled by eight motors. An algorithm plans the movement or rotation path of the end effector, along with the corresponding control positions and speeds of the eight cables. Commands are then issued to the different motor drivers via the controller.

[0033] Trajectory generation methods combined Figure 2 The end effector is described as a cuboid with its geometric center at coordinates (x, y, z) and dimensions a, b, and c. The length of the ropes connecting the eight fixed points of the end effector to the eight machined pulleys is l. i The length is fixed, and i takes values ​​of 1, 2, ..., 8. i Let b be the coordinates of the 8 pulleys. i Let R be the coordinates of the eight fixed points of the end effector, and R be the rotation matrix of the actuator. The expression for the fixed rope length is obtained as follows:

[0034] l i =a i -r-Rb i , i = 1, 2, ..., 8.

[0035] Taking the upward-moving straight line of the longest trajectory segment as an example, the rotation matrix is ​​the identity matrix E, i.e., l i =a i -rb i The speed of each rope can be obtained by differentiating the value of each rope segment:

[0036] in

[0037] During the operation of the end effector, each rope is controlled individually by its own driver. Although each motor has encoder feedback, there may be some differences and uncertainties in the driver components. The command execution time and motor response time may differ, and there may be situations where multiple motors cannot reach the target position point accurately at the same time.

[0038] To address the deficiencies described in the prior art, this application provides a control method for a rope-driven parallel robot. This method can be used to control eight motors of a rope-driven parallel robot. For any single target motor, the specific steps of the control method can be referred to... Figure 1 , Figure 1 This is a schematic diagram illustrating the steps of a rope-driven parallel robot control method. Figure 1 The control method may include, but is not limited to, steps S101-S102:

[0039] S101. Obtain the current position of the target motor; the target motor is the motor that moves first.

[0040] Understandably, as the motor rotates, the tightening of the rope causes the motor to move along a certain trajectory, and the current position of the motor can be any point on that trajectory. However, due to differences in response time and subtle variations in the internal magnetic field of each motor, the starting point of movement for each motor differs. Therefore, the target motor could be the first to move or the motor that started moving at the earliest time.

[0041] In some feasible embodiments of this application, the acquisition module can acquire the current position of the target motor, and then connect to the processor via wired or wireless means to send the acquired current position of the target motor to the processor for further processing.

[0042] It should be noted that the aforementioned wired connection methods can include connections between mobile devices and host computers, connections between host computers, and other wired connections between known or future-developed devices and host computers; while the aforementioned wireless connection methods can include, but are not limited to, 3G / 4G / 5G connections, Wi-Fi connections, Bluetooth connections, WiMAX connections, Zigbee connections, UWB (Ultra Wide Band) connections, and other known or future-developed wireless connection methods. The acquisition module can be a separate device, such as a processor that converts motor codes into corresponding positions; the acquisition module can be integrated with the processor into a single module.

[0043] S102. Control the target motor to move at a first speed. When the distance difference between the current position and the preset target position is less than or equal to a first preset threshold, adjust the first speed to a second speed. The second speed is less than the first speed.

[0044] Understandably, the first speed can be a preset speed. After the motor is started, it can gradually accelerate to the preset speed within a short period of time. The first speed can be any value, and the specific value can be determined according to specific needs. The second speed is the speed obtained after the motor reaches the designated position. The second speed can be any value smaller than the first speed, and the specific value can be determined according to specific needs.

[0045] In some feasible embodiments of this application, the controller can first control the target motor to move at a first speed. When the distance difference between the current position and the preset target position of the target motor is less than or equal to a first preset threshold, the controller can control the motor to move at a second speed, wherein the second speed can be less than the first speed.

[0046] Furthermore, in some feasible embodiments of this application, the rope-driven parallel robot control method may further include: S103, when the distance difference between the current position of the target motor and the target position is greater than a first preset threshold, controlling the motor to move at a first speed. Specifically, when the motor has not yet reached the preset area, the controller can control the motor to continue moving at the first speed.

[0047] Furthermore, in some feasible embodiments of this application, the first speed and the second speed satisfy the following relationship:

[0048] V1 = V0 / N;

[0049] Where V1 is the second velocity, V0 is the first velocity, and N is 2≤N≤10, where N is an integer.

[0050] Furthermore, in some feasible embodiments of this application, the step of adjusting the first speed to a second speed when the distance difference between the current position and the preset target position is less than or equal to a first preset threshold may specifically include: for any target motor, when the distance difference between the current position of the motor and the preset target position is less than or equal to the first preset threshold, adjusting the speed of the target motor from the first speed to the second speed, and controlling the motor with the second speed until the positions of the other seven motors reach the first preset position. Specifically, the first preset position may be any position point in the trajectory of the other seven motors whose distance difference from the target position is less than or equal to the first preset threshold.

[0051] Furthermore, in some feasible embodiments of this application, the rope-driven parallel robot control method may further include: when the distance difference between the position of any target motor and the target position is less than or equal to a first preset threshold, and the distance difference between the positions of the remaining seven motors and the second preset position is less than or equal to the second preset threshold, controlling all eight motors to move at a third speed. Specifically, when the first motor to start approaches the target position and the other seven motors also reach the target point of the trajectory corresponding to the seven motors, the control module can control all eight motors to move at the third speed. It is understood that the third speed can be the same as, greater than, or less than the first speed, and the specific speed value can be determined according to the actual situation.

[0052] Furthermore, in some feasible embodiments of this application, the third speed is greater than the second speed. Specifically, the second speed is a speed that is adjusted to be smaller than the first speed. In this application, after all seven motors have reached the target position, the motors will be adjusted to a third speed that is greater than the decelerated speed.

[0053] The specific calculation principle of this application is explained below with reference to the accompanying drawings:

[0054] Reference Figure 4 In this embodiment, the motor's first speed can be set to vn, where n is 1-8; the second speed to vn / N; and the third speed to vdn, where n is 1-8. A first preset threshold is value. This threshold value is located in a small area near the target point. When the motor's preset first speed vn reaches this threshold range, it is considered to have reached the target point. The system checks whether all motors have entered the threshold range. Once all motors have reached the threshold, the running trajectory is switched to the speed vdn corresponding to the next target point state. If any motor has not reached the threshold, it continues running. Motors that have reached the threshold run at speed vn / N, where vn / N is less than vn.

[0055] For example, the current position of motor 1 is s1, the current running speed is v1, the target point position is sd1, and the target point speed is vd1. When sd1-s1<=value, a threshold is set. At this time, the current value speed is set to v1 / N.

[0056] Motor 2's current position is s2, current running speed is v2, target point position is sd2, target point speed is vd2. When sd2-s2<=value, a threshold is set. At this time, the current speed is set to v2 / N.

[0057] Motor 3 current position s3, current running speed v3, target point position sd3, target point speed vd3. When sd3-s3<=value, a threshold is set. At this time, the current speed is set to v3 / N.

[0058] Motor 4 current position s4, current running speed v4, target point position sd4, target point speed vd4. When sd4-s4<=value, a threshold is set. At this time, the current speed is set to v4 / N.

[0059] Motor 5's current position s5, current running speed v5, target point position sd5, target point speed vd5. When sd5-s5<=value, a threshold is set. At this time, the current speed is set to v5 / N.

[0060] Motor 6 current position s6, current running speed v6, target point position sd6, target point speed vd6. When sd6-s6<=value, a threshold is set. At this time, the current speed is set to v6 / N.

[0061] Motor 7 current position s7, current running speed v7, target point position sd7, target point speed vd7. When sd7-s7<=value, a threshold is set. At this time, the current value speed is set to v7 / N.

[0062] Motor 8's current position s8, current running speed v8, target point position sd8, target point speed vd8. When sd8-s8<=value, a threshold is set. At this time, the current speed is set to v8 / N.

[0063] Here, N takes the value of an integer from 1 to 10. When N = 1, the motor continues to run at the current speed after entering the threshold, and the speed remains unchanged.

[0064] When N is an integer greater than 1, the motor decelerates after entering the threshold. When N = 2, the motor speed within the threshold is v1 / 2, that is, the motor speed is halved.

[0065] Once all 8 motors have entered the threshold range, the current motion state switches to the state of the next trajectory planning target point, and the motor moves to the position of the next point at the speed of the next point (vdn).

[0066] In addition, refer to Figure 5 ,and Figure 1Corresponding to the method described above, embodiments of this application also provide a rope-traction parallel robot control system. This system can be used to control eight motors of a rope-traction parallel robot. The system may include an acquisition unit 1001 and a first control unit 1002. The acquisition unit 1001 can be signal-connected to the first control unit 1002. The acquisition unit 1001 can be used to determine the current position of the target motor; the target motor is the motor that moves first; the first control module 1002 can control the motor to move at a first speed, and when the distance difference between the current position and the preset target position is less than or equal to a first preset threshold, the first speed is adjusted to a second speed; wherein the second speed is less than the first speed.

[0067] It is understandable that the acquisition unit can be integrated with the first control unit in a processing module, or it can transmit data with the first control unit through a communication protocol.

[0068] Furthermore, in some feasible embodiments of this application, the rope-traction parallel robot control system may further include a second control unit 1003. The second control unit 1003 may be used to control the motor to move at a first speed when the distance difference between the current position and the preset target position is greater than a first preset threshold.

[0069] It is understandable that the second control unit may belong to the same processor or a different part of the processing chip as the first control unit, or it may be different control units that execute different control algorithms on the same processor.

[0070] It should be noted that the content of the above-described rope-traction parallel robot control method embodiments is applicable to this rope-traction parallel robot control system embodiment. The specific functions implemented by this rope-traction parallel robot control system embodiment are the same as those of the above-described rope-traction parallel robot control method embodiments, and the beneficial effects achieved are also the same as those achieved by the above-described rope-traction parallel robot control method embodiments.

[0071] and Figure 1 Corresponding to the method described herein, embodiments of this application also provide a rope-traction parallel robot control device, the specific structure of which can be referred to... Figure 6 ,include:

[0072] At least one processor 1011;

[0073] At least one memory 1012 is used to store at least one program;

[0074] When the at least one program is executed by the at least one processor, the at least one processor implements the rope-traction parallel robot control method.

[0075] It should be noted that the content of the above method embodiments is applicable to the present device embodiments. The specific functions implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0076] and Figure 1 Corresponding to the method described above, this application also provides a storage medium storing processor-executable instructions, which, when executed by the processor, are used to perform the rope-traction parallel robot control method.

[0077] It should be noted that the content of the above-described rope-traction parallel robot control method embodiments is applicable to this storage medium embodiment. The specific functions implemented by this storage medium embodiment are the same as those of the above-described rope-traction parallel robot control method embodiments, and the beneficial effects achieved are also the same as those achieved by the above-described rope-traction parallel robot control method embodiments.

[0078] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this application are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0079] Furthermore, although this application is described in the context of functional modules, it should be understood that, unless otherwise stated to the contrary, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding this application. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional technology for an engineer. Therefore, those skilled in the art can implement the application set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of this application, which is determined by the full scope of the appended claims and their equivalents.

[0080] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several programs to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0081] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable programs for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, a program execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can retrieve and execute a program from or in conjunction with such a program execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can mean any means that can contain, store, communicate, propagate, or transmit a program for use by or in conjunction with a program execution system, apparatus, or device.

[0082] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0083] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable program execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0084] In the foregoing description of this specification, the references to terms such as "one embodiment," "another embodiment," or "some embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the 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.

[0085] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

[0086] The above is a detailed description of the preferred embodiments of this application, but this application is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A control method for a rope-driven parallel robot, characterized in that, The control method for controlling eight motors in a rope-driven parallel robot includes, for any one target motor: Obtain the current position of the target motor; the target motor is the motor that moves first. The target motor is controlled to move at a first speed. For any target motor, when the distance difference between the current position of the target motor and the preset target position is less than or equal to a first preset threshold, the speed of the target motor is adjusted from the first speed to a second speed, and the target motor is controlled at the second speed until the positions of the other seven motors reach the first preset position. The first preset position is any point in the trajectory of the other seven motors where the distance difference between it and its corresponding target position is less than or equal to the first preset threshold. The motors among the other seven motors that have not reached the first preset position continue to run, while the motors that have reached the first preset position are controlled to run at the second speed. When the distance difference between the position of any one of the target motors and the target position is less than or equal to a first preset threshold, and the distance difference between the positions of the other seven motors and their respective second preset positions is less than or equal to a second preset threshold, all eight motors are controlled to move at a third speed; wherein the second speed is less than the first speed, and the third speed is greater than the second speed.

2. The rope-traction parallel robot control method according to claim 1, characterized in that, The control method further includes: when the distance difference between the current position of the target motor and the target position is greater than a first preset threshold, controlling the motor to move at the first speed.

3. The rope-traction parallel robot control method according to claim 1, characterized in that, The first velocity and the second velocity satisfy the following relationship: V1 = V0 / N; Where V1 is the second velocity, V0 is the first velocity, and N is 2≤N≤10, where N is an integer.

4. A rope-driven parallel robot control system, characterized in that, The system comprises eight motors for controlling a rope-driven parallel robot, and includes: The acquisition unit is used to acquire the current position of the target motor; the target motor is the motor that moves first. A first control unit is configured to control the movement of the target motor at a first speed. For any target motor, when the distance difference between the current position of the target motor and a preset target position is less than or equal to a first preset threshold, the speed of the target motor is adjusted from the first speed to a second speed, and the target motor is controlled at the second speed until the positions of the other seven motors reach the first preset position. The first preset position is any point in the trajectory of the other seven motors where the distance difference between it and its corresponding target position is less than or equal to the first preset threshold. The motors among the other seven motors that have not reached the first preset position continue to run, while the motors that have reached the first preset position are controlled to run at the second speed. When the distance difference between the position of any one of the target motors and the target position is less than or equal to a first preset threshold, and the distance difference between the positions of the other seven motors and their respective second preset positions is less than or equal to a second preset threshold, all eight motors are controlled to move at a third speed; wherein the second speed is less than the first speed, and the third speed is greater than the second speed.

5. The rope-traction parallel robot control system according to claim 4, characterized in that, The system further includes a second control unit, used to control the motor to move at the first speed when the distance difference between the current position and the preset target position is greater than a first preset threshold.

6. A control device for a rope-driven parallel robot, characterized in that... include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements a rope-traction parallel robot control method as described in any one of claims 1-3.

7. A storage medium storing processor-executable instructions, characterized in that, The processor-executable instructions, when executed by the processor, are used to perform a rope-traction parallel robot control method as described in any one of claims 1-3.

Images