Robot control method, robot control device, robot, storage medium, and program product

Abstract

The application discloses a robot control method and device, a robot, a storage medium and a computer program product. The method comprises the following steps: pre-planning a motion trajectory of a robot end tool according to a robot operation parameter, determining an expected bending moment to be borne by the tool; when the expected bending moment is greater than a preset threshold, determining a robot operation rate, controlling the speed and acceleration of the tool according to the operation rate, so that the bending moment borne by the tool does not exceed the preset threshold. According to the scheme, the bending moment borne by the end tool is calculated in advance in the motion planning process of the robot, and the operation rate is adjusted in the actual motion process, so that the bending moment borne by the end tool in the motion process is less than the bearing limit, the tool is prevented from being bent or even broken, the robot is ensured to stably operate, and the operation safety is improved.

Description

Technical Field

[0001] This invention belongs to the field of robot control technology, specifically relating to a robot control method, device, robot, storage medium, and computer program product. Background Technology

[0002] A robot is an automated device that can perform a series of preset tasks. Tools required for the task, such as probes and welding torches, are often attached to the robot's end effector. The structures of these external devices vary. If there is an excessively long strip structure, the force acting perpendicular to the long end of the tool may be too large when the robot's end effector moves, causing the tool to bear an excessive bending moment, which may lead to deformation, bending, or even breakage.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The purpose of this invention is to provide a robot control method, device, robot, storage medium, and computer program product to solve the problem in related solutions where excessive bending moment on the robot's end effector leads to deformation, bending, or even breakage. This invention achieves the effect of pre-calculating the bending moment on the end effector during the robot's motion planning process and adjusting the operating ratio during actual motion to ensure that the bending moment on the end effector is less than its tolerance limit, thus preventing bending or even breakage, ensuring stable robot operation, and improving operational safety.

[0005] This invention provides a robot control method, wherein the robot's end effector is equipped with a tool; the method includes: acquiring the robot's operating parameters; pre-planning the motion trajectory of the tool based on the operating parameters, determining the bending moment that the tool will bear, denoted as the expected bending moment; when the expected bending moment is greater than a preset threshold, determining the robot's operating ratio, and controlling the speed and acceleration of the tool according to the operating ratio, so that the bending moment experienced by the tool does not exceed the preset threshold.

[0006] In some implementations, the motion trajectory of the tool is pre-planned based on the operating parameters to determine the bending moment that the tool will bear. This includes: performing simulation planning interpolation at fixed time intervals based on the operating parameters, calculating the estimated motion parameters at each interpolation point, the estimated motion parameters including estimated velocity and estimated acceleration; calculating the centrifugal force and inertial force that the tool will bear based on the estimated motion parameters; vector combining the centrifugal force, the inertial force, and the gravity acting on the tool to obtain a three-dimensional composite force; projecting the three-dimensional composite force onto a plane perpendicular to the long axis of the tool to obtain a projected force; and determining the product of the projected force and the length of the tool as the bending moment that the tool will bear.

[0007] In some embodiments, the long axis of the tool is the maximum extension axis through the center of mass of the tool.

[0008] In some embodiments, the tool length is the maximum distance from the fixed end to the distal end of the tool.

[0009] In some implementations, determining the operating ratio of the robot and controlling the speed and acceleration of the tool based on the operating ratio includes: decomposing the bending moment acting on the tool to obtain a gravity component and a motion component; calculating the operating ratio when the bending moment acting on the tool does not exceed a preset threshold based on a preset formula, the gravity component, and the motion component; multiplying the estimated speed by the operating ratio to obtain a new estimated speed; multiplying the estimated acceleration by the square of the operating ratio to obtain a new estimated acceleration; and controlling the tool to move at the new estimated speed and the new estimated acceleration.

[0010] In some implementations, the preset formula can calculate the operating rate when the bending moment experienced by the tool equals a preset threshold; the preset formula is:

[0011]

[0012] Where K is the operating ratio, M lim M is a preset threshold. g M is the gravitational component. av The motion component is referred to here.

[0013] In conjunction with the above method, another aspect of the present invention provides a robot control device, wherein the end effector of the robot is provided with a tool; the device includes: an acquisition unit configured to acquire the operating parameters of the robot; a pre-planning unit configured to pre-plan the motion trajectory of the tool according to the operating parameters, and determine the bending moment that the tool will bear, denoted as the expected bending moment; and a control unit configured to determine the operating rate of the robot when the expected bending moment is greater than a preset threshold, and control the speed and acceleration of the tool according to the operating rate, so that the bending moment subjected to the tool does not exceed the preset threshold.

[0014] In some implementations, the pre-planning unit pre-plans the motion trajectory of the tool based on the operating parameters and determines the bending moment that the tool will bear. This includes: performing simulated planning interpolation at fixed time intervals based on the operating parameters, calculating the estimated motion parameters at each interpolation point, the estimated motion parameters including estimated velocity and estimated acceleration; calculating the centrifugal force and inertial force that the tool will bear based on the estimated motion parameters; vector combining the centrifugal force, the inertial force, and the gravity acting on the tool to obtain a three-dimensional composite force; projecting the three-dimensional composite force onto a plane perpendicular to the long axis of the tool to obtain a projected force; and determining the product of the projected force and the length of the tool as the bending moment that the tool will bear.

[0015] In some embodiments, the long axis of the tool is the maximum extension axis through the center of mass of the tool.

[0016] In some embodiments, the tool length is the maximum distance from the fixed end to the distal end of the tool.

[0017] In some implementations, the control unit determines the operating ratio of the robot and controls the speed and acceleration of the tool according to the operating ratio, including: decomposing the bending moment acting on the tool to obtain a gravity component and a motion component; calculating the operating ratio when the bending moment acting on the tool does not exceed a preset threshold according to a preset formula, the gravity component, and the motion component; multiplying the estimated speed by the operating ratio to obtain a new estimated speed; multiplying the estimated acceleration by the square of the operating ratio to obtain a new estimated acceleration; and controlling the tool to move at the new estimated speed and the new estimated acceleration.

[0018] In some implementations, the preset formula can calculate the operating rate when the bending moment experienced by the tool equals a preset threshold; the preset formula is:

[0019]

[0020] Where K is the operating ratio, M lim M is a preset threshold.g M is the gravitational component. av The motion component is referred to here.

[0021] In conjunction with the above-described device, the present invention further provides a robot, comprising: the control device for the robot described above.

[0022] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device on which the storage medium is located executes the robot control method described above.

[0023] In conjunction with the above method, the present invention further provides a computer program product comprising a computer program that, when processed and executed, implements the steps of the above-described robot control method.

[0024] The present invention pre-plans the motion trajectory of the robot's end effector based on the robot's operating parameters, determining the expected bending moment the tool will withstand. When the expected bending moment exceeds a preset threshold, the robot's operating rate is determined, and the tool's speed and acceleration are controlled according to the operating rate to ensure that the bending moment experienced by the tool does not exceed the preset threshold. Thus, by calculating the bending moment experienced by the end effector in advance during the robot's motion planning process and adjusting the operating rate during actual movement, the bending moment experienced by the end effector during movement is guaranteed to be less than its withstand limit, preventing bending or even breakage of the tool, ensuring stable robot operation, and improving operational safety.

[0025] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating an embodiment of the robot control method of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of an embodiment of the robot control device of the present invention;

[0029] Figure 3 This is a schematic diagram of the robot's end effector.

[0030] Figure 4 This is a flowchart illustrating another embodiment of the robot control method of the present invention.

[0031] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0032] 1-End flange; 2-Tool; 101-Acquisition unit; 102-Pre-planning unit; 103-Control unit. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0034] According to an embodiment of the present invention, a method for controlling a robot is provided, wherein the end effector of the robot is provided with a tool, such as... Figure 3 As shown, a tool 2 is mounted on the robot's end effector, and the robot's end flange 1 is used to secure the tool 2. Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. The robot control method may include steps S110 to S130.

[0035] In step S110, the operating parameters of the robot are obtained.

[0036] Operating parameters are fundamental to calculating the bending moment of the end effector, and include, but are not limited to, physical parameters such as the tool's target position, velocity, acceleration, mass, length, and center of gravity. Among these, the tool's mass and length directly affect the calculation of centrifugal force and bending moment; their absence or inaccuracy will lead to deviations in bending moment prediction, failing to accurately protect the tool.

[0037] In step S120, the motion trajectory of the tool is pre-planned according to the operating parameters, and the bending moment that the tool will bear is determined and recorded as the expected bending moment.

[0038] The varying velocities, accelerations, and curvatures at different points along a robot's trajectory cause dynamic changes in the forces acting on the tool. Therefore, pre-planning is performed before the robot begins actual movement. By calculating the position, velocity, and acceleration of the end effector trajectory, and adding the length and mass of the end effector tool, the bending moment the tool experiences at each moment during movement can be calculated. If any exceeding this range is detected, the operating rate is adjusted to reduce the end effector's velocity and acceleration, ensuring the bending moment remains within acceptable limits. Pre-planning and calculating the bending moment for the entire trajectory in advance prevents tool damage caused by real-time calculation delays during actual operation.

[0039] In some implementations, step S120, which involves pre-planning the motion trajectory of the tool based on the operating parameters and determining the specific process of the bending moment that the tool will bear, includes steps S210 to S250.

[0040] Step S210: Perform simulation planning interpolation according to the operating parameters at fixed time intervals, and calculate the estimated motion parameters for each interpolation point. The estimated motion parameters include estimated velocity and estimated acceleration.

[0041] Robot trajectories are typically defined by discrete points (such as start point, end point, and intermediate key points), and continuous paths need to be generated using interpolation algorithms. Specifically, the tool's motion is simulated beforehand in the program. Given parameters (velocity, acceleration, agility, and distance), simulated interpolation is performed to observe the expected motion effects. Based on the simulation interpolation results, necessary calculations are performed, such as the torque borne by the tool and joints at each interpolation instant. These results are then used to adjust the actual interpolation effect. Interpolation refers to dividing the motion trajectory evenly over time; the absolute position at each instant is called the interpolation position. Originally, the interpolation point / absolute joint position was sent to the servo motor at fixed intervals. Here, however, it is simulated interpolation; only calculations are performed, and no actual transmission is performed.

[0042] Interpolating at fixed time intervals (e.g., 2ms) discretizes the trajectory into dense calculation points, accurately capturing instantaneous changes in velocity and acceleration. Adjusting the interpolation interval (e.g., reducing it from 2ms to 1ms) can improve calculation accuracy, balancing real-time performance and accuracy.

[0043] Step S220: Calculate the centrifugal force and inertial force that the tool will bear based on the estimated motion parameters.

[0044] The formula for calculating centrifugal force is: The formula for calculating the inertial force generated by acceleration is: m is the mass of the tool, v is the estimated velocity, and a is the estimated acceleration.

[0045] Step S230: The centrifugal force, the inertial force, and the gravity acting on the tool are vector-synthesized to obtain a three-dimensional composite force.

[0046] The gravity of the tool Centrifugal force F v Inertial force F a Gravity G is combined into F 合 ,Right now The composite force covers the robot's full-attitude operation (such as gravity and inertial force being collinear during vertical movement, and centrifugal force being perpendicular to gravity during horizontal turning), thus avoiding errors caused by single-force analysis.

[0047] Step S240: Project the three-dimensional spatial composite force onto a plane perpendicular to the long axis of the tool to obtain the projected force.

[0048] Projected force is the external force F that acts on the tool during bending moment. 外 , θ is the angle between the resultant force and the plane. The projected force only retains the transverse force that causes the tool to bend, ignoring the axial force (axial force only produces tension or compression, not bending moment). Furthermore, reducing the three-dimensional problem to a two-dimensional plane can reduce computational complexity.

[0049] In some implementations, the long axis of the tool is the longest extension axis passing through the tool's center of mass. The center of mass is the center of the tool's mass distribution, while the "longest extension axis" determines the longest direction of the tool in space. For example, for a long, narrow welding torch, its long axis is a straight line along the slender direction of the torch and passing through the torch's center of mass; for irregularly shaped tools, their center of mass and longest extension direction can be determined through CAD modeling or algorithmic calculation.

[0050] Step S250: The product of the projected force and the tool length is determined as the bending moment that the tool will bear.

[0051] Bending moment L represents the length of the tool. Through a five-step process—trajectory discretization, mechanical decomposition, spatial synthesis, planar projection, and bending moment calculation—a multi-force-field coupled mechanical model is constructed. This model covers all robot posture operation scenarios and improves computational efficiency through dimensionality reduction projection. It accurately captures the key factors causing tool bending, providing precise basis for subsequent operation rate adjustment and enabling quantitative assessment and preventative protection of the tool's forces.

[0052] In some implementations, the tool length is the maximum distance from the fixed end to the distal end of the tool. The fixed end refers to the fixed connection point between the tool and the robot end flange or connecting component, while the distal end is the farthest point of the tool away from the fixed end. For example, for a gripper at the end of a robotic arm, the fixed end is the part where the gripper connects to the robotic arm, and the distal end is the farthest point of the gripper's fingertips when it is open; for a drill tool, the fixed end is the end connected to the spindle, and the distal end is the drill tip.

[0053] In step S130, when the expected bending moment is greater than a preset threshold, the operating rate of the robot is determined, and the speed and acceleration of the tool are controlled according to the operating rate so that the bending moment experienced by the tool does not exceed the preset threshold.

[0054] The preset threshold is the maximum threshold that the tool can withstand. When the pre-planned bending moment exceeds the tool's threshold, the speed and acceleration need to be reduced by adjusting the running rate to decrease centrifugal force and inertial force, thereby reducing the bending moment to a safe range. This process only adjusts motion parameters without changing the trajectory geometry, making it suitable for scenarios with high path accuracy requirements, such as welding and spraying.

[0055] This solution avoids the risk of real-time control lag by predicting the stress at each point on the trajectory in advance. Without changing the geometry of the trajectory, it ensures that the bending moment that the tool can withstand is within the safety threshold, which not only improves the safety of robot operation, but also ensures the path accuracy and efficiency of welding, handling and other operations. It is a universal protection solution applicable to different tool types.

[0056] In some implementations, step S130, which involves determining the operating rate of the robot and controlling the speed and acceleration of the tool based on the operating rate, includes steps S310 to S340.

[0057] Step S310: Decompose the bending moment on the tool to obtain the gravity component and the motion component.

[0058] The bending moment borne by the tool is generated by both gravity (static load) and motion (dynamic load), with the gravity component M. g Caused by the tool's own weight, and related to its orientation (e.g., maximum when horizontal, zero when vertical); motion component M av Caused by centrifugal force and inertial force, it is related to velocity v and acceleration a. Through vector analysis, the total bending moment M is decomposed into gravitational and kinematic components, i.e.:

[0059]

[0060] Where, θ g Let θ be the angle between the gravity vector and the projection plane. av This is the angle between the resultant force vector of centrifugal force and inertial force and the projection plane. When adjusting the magnification, only the centrifugal force and inertial force are adjusted.

[0061] Step S320: Calculate the operating rate when the bending moment experienced by the tool does not exceed a preset threshold, based on the preset formula, the gravity component, and the motion component.

[0062] In some embodiments, the preset formula can calculate the operating rate when the bending moment experienced by the tool equals a preset threshold; the preset formula is:

[0063]

[0064] Where K is the operating ratio, M lim M is a preset threshold. gM is the gravitational component. av The motion component is referred to here.

[0065] Specifically, if the bending moment experienced by the tool is to be exactly equal to a preset threshold, then the bending moment after the magnification adjustment is M2 = M lim =M g +M av K 2 That is, the operating ratio

[0066] In some embodiments, if the tool is lightweight, the bending moment caused by its own weight can be ignored, then M = M av M2 = M lim =M av K 2 Operating rate

[0067] Step S330: Multiply the estimated speed by the operating ratio to obtain a new estimated speed; multiply the estimated acceleration by the square of the operating ratio to obtain a new estimated acceleration.

[0068] The scaling factor adjusts the robot's operating rate, which is a parameter for a trajectory segment or the overall motion. Taking time-scaling-based scaling factor adjustment as an example: at 100% scaling factor, the original motion planning interpolation was 2ms, meaning interpolation points (absolute joint positions) were sent every 2ms; at 50% scaling factor, the time is scaled by 0.5, and every 2ms, the original 1ms interpolation points are sent. Therefore, the velocity in the entire planning segment becomes 0.5 times the original, and the acceleration becomes 0.5 * 0.5 = 0.25 times the original.

[0069] By altering the time distribution of the interpolation points, the overall motion velocity can be adjusted while maintaining the trajectory geometry. Specifically, if the original motion time is T, containing N interpolation points, then the time interval between each interpolation point is Δt1 = T / N; after time scaling, the motion time becomes T' = T / K, and the time interval between interpolation points becomes Δt2 = T' / N = T / (N·K) = Δt1 / K; velocity v = displacement / time, therefore the new velocity v2 = v1·K. Acceleration is the derivative of velocity with respect to time, i.e., a = dv / dt. When the time scaling is t' = t / K, the velocity becomes v' = v·K, then a' = a·K. 2 That is, the acceleration is proportional to the square of the multiplier K.

[0070] Step S340: Control the tool to move with a new estimated speed and a new estimated acceleration.

[0071] After the magnification adjustment, the motion components and the new centrifugal force are obtained based on the new predicted velocity and new predicted acceleration. New inertial force Thus, new motion components When the tool moves along a preset trajectory under new motion components, the bending moment it experiences will never exceed a threshold. This enables precise control of the force applied to the tool, distinguishes between static and dynamic load characteristics, avoids excessive deceleration due to misjudgment of gravity or overload risks caused by neglecting dynamic loads, and maximizes operational efficiency while ensuring safety.

[0072] Figure 4 This is a flowchart illustrating another embodiment of the robot control method of the present invention, as shown below. Figure 4 As shown, the method includes:

[0073] Step 1: Parse the motion commands set by the user to obtain the target position and various motion parameters.

[0074] Step 2: Using the parameters obtained in Step 1, perform pre-planning to obtain the predicted motion trajectory, velocity, and acceleration.

[0075] Step 3: Calculate the bending moment that the tool in the pre-planned design will bear.

[0076] Step 4: Determine whether the bending moment borne by the tool in the pre-planned program is greater than the tool bending moment limit. If the bending moment is greater than the bending moment limit, proceed to step 5; otherwise, directly use the trajectory from the pre-processing stage for execution.

[0077] Step 5: Perform magnification adjustment calculations and re-plan the motion to control the tool's operation. This ensures that the bending moment experienced by the end effector during robot movement remains within its tolerance range, preventing the end effector from bending or breaking due to excessive bending moment during use.

[0078] The technical solution of this embodiment pre-plans the motion trajectory of the robot's end effector based on the robot's operating parameters, determining the expected bending moment the tool will bear. When the expected bending moment exceeds a preset threshold, the robot's operating rate is determined, and the tool's speed and acceleration are controlled according to the operating rate to ensure that the bending moment experienced by the tool does not exceed the preset threshold. Thus, by calculating the bending moment experienced by the end effector in advance during the robot's motion planning process and adjusting the operating rate during actual movement, the bending moment experienced by the end effector during movement is guaranteed to be less than its bearing limit, preventing bending or even breakage of the tool, ensuring stable robot operation, and improving operational safety.

[0079] According to embodiments of the present invention, a robot control device corresponding to a robot control method is also provided. For example... Figure 3 As shown, tool 2 is mounted on the robot's end effector, and the robot's end flange 1 is used to secure tool 2. (See also...) Figure 2The diagram shows a structural schematic of an embodiment of the device of the present invention. The control device of the robot may include: an acquisition unit 101, a pre-planning unit 102, and a control unit 103.

[0080] The acquisition unit 101 is configured to acquire the operating parameters of the robot.

[0081] Operating parameters are fundamental to calculating the bending moment of the end effector, and include, but are not limited to, physical parameters such as the tool's target position, velocity, acceleration, mass, length, and center of gravity. Among these, the tool's mass and length directly affect the calculation of centrifugal force and bending moment; their absence or inaccuracy will lead to deviations in bending moment prediction, failing to accurately protect the tool.

[0082] The pre-planning unit 102 is configured to pre-plan the motion trajectory of the tool based on the operating parameters and determine the bending moment that the tool will bear, denoted as the expected bending moment.

[0083] The varying velocities, accelerations, and curvatures at different points along a robot's trajectory cause dynamic changes in the forces acting on the tool. Therefore, pre-planning is performed before the robot begins actual movement. By calculating the position, velocity, and acceleration of the end effector trajectory, and adding the length and mass of the end effector tool, the bending moment the tool experiences at each moment during movement can be calculated. If any exceeding this range is detected, the operating rate is adjusted to reduce the end effector's velocity and acceleration, ensuring the bending moment remains within acceptable limits. Pre-planning and calculating the bending moment for the entire trajectory in advance prevents tool damage caused by real-time calculation delays during actual operation.

[0084] In some implementations, the pre-planning unit 102 pre-plans the motion trajectory of the tool based on the operating parameters, and determines the specific bending moment that the tool will withstand, including:

[0085] The pre-planning unit 102 is further configured to perform simulated planning interpolation at fixed time intervals according to the operating parameters, and calculate the estimated motion parameters for each interpolation point, wherein the estimated motion parameters include estimated velocity and estimated acceleration.

[0086] Robot trajectories are typically defined by discrete points (such as start point, end point, and intermediate key points), and continuous paths need to be generated using interpolation algorithms. Specifically, the tool's motion is simulated beforehand in the program. Given parameters (velocity, acceleration, agility, and distance), simulated planning and interpolation are performed to observe the expected motion effects. Based on the simulation interpolation results, necessary calculations are performed, such as the torque borne by the tool and joints at each interpolation instant. These results are then used to adjust the actual interpolation effect. Interpolation refers to dividing the motion trajectory evenly over time; the absolute position at each instant is called the interpolation position. Originally, the interpolation point / absolute joint position was sent to the servo motor at fixed intervals. Here, however, it is simulated interpolation; only calculations are performed, and no actual transmission is performed.

[0087] Interpolating at fixed time intervals (e.g., 2ms) discretizes the trajectory into dense calculation points, accurately capturing instantaneous changes in velocity and acceleration. Adjusting the interpolation interval (e.g., reducing it from 2ms to 1ms) can improve calculation accuracy, balancing real-time performance and accuracy.

[0088] The pre-planning unit 102 is further configured to calculate the centrifugal force and inertial force that the tool will bear based on the estimated motion parameters.

[0089] The formula for calculating centrifugal force is: The formula for calculating the inertial force generated by acceleration is: m is the mass of the tool, v is the estimated velocity, and a is the estimated acceleration.

[0090] The pre-planning unit 102 is further configured to perform vector synthesis of the centrifugal force, the inertial force, and the gravity acting on the tool to obtain a three-dimensional spatial composite force.

[0091] The gravity of the tool Centrifugal force F v Inertial force F a Gravity G is combined to form F 合 ,Right now The composite force covers the robot's full-attitude operation (such as gravity and inertial force being collinear during vertical movement, and centrifugal force being perpendicular to gravity during horizontal turning), thus avoiding errors caused by single-force analysis.

[0092] The pre-planning unit 102 is further configured to project the three-dimensional spatial composite force onto a plane perpendicular to the long axis of the tool to obtain a projected force.

[0093] Projected force is the external force F that acts on the tool during bending moment. 外 , θ is the angle between the resultant force and the plane. The projected force only retains the transverse force that causes the tool to bend, ignoring the axial force (axial force only produces tension or compression, not bending moment). Furthermore, reducing the three-dimensional problem to a two-dimensional plane can reduce computational complexity.

[0094] In some implementations, the long axis of the tool is the longest extension axis passing through the tool's center of mass. The center of mass is the center of the tool's mass distribution, while the "longest extension axis" determines the longest direction of the tool in space. For example, for a long, narrow welding torch, its long axis is a straight line along the slender direction of the torch and passing through the torch's center of mass; for irregularly shaped tools, their center of mass and longest extension direction can be determined through CAD modeling or algorithmic calculation.

[0095] The pre-planning unit 102 is further configured to determine the product of the projected force and the tool length as the bending moment that the tool will bear.

[0096] Bending moment L represents the length of the tool. Through a five-step process—trajectory discretization, mechanical decomposition, spatial synthesis, planar projection, and bending moment calculation—a multi-force-field coupled mechanical model is constructed. This model covers all robot posture operation scenarios and improves computational efficiency through dimensionality reduction projection. It accurately captures the key factors causing tool bending, providing precise basis for subsequent operation rate adjustment and enabling quantitative assessment and preventative protection of the tool's forces.

[0097] In some implementations, the tool length is the maximum distance from the fixed end to the distal end of the tool. The fixed end refers to the fixed connection point between the tool and the robot end flange or connecting component, while the distal end is the farthest point of the tool away from the fixed end. For example, for a gripper at the end of a robotic arm, the fixed end is the part where the gripper connects to the robotic arm, and the distal end is the farthest point of the gripper's fingertips when it is open; for a drill tool, the fixed end is the end connected to the spindle, and the distal end is the drill tip.

[0098] The control unit 103 is configured to determine the operating rate of the robot when the expected bending moment is greater than a preset threshold, and control the speed and acceleration of the tool according to the operating rate so that the bending moment on the tool does not exceed the preset threshold.

[0099] The preset threshold is the maximum threshold that the tool can withstand. When the pre-planned bending moment exceeds the tool's threshold, the speed and acceleration need to be reduced by adjusting the running rate to decrease centrifugal force and inertial force, thereby reducing the bending moment to a safe range. This process only adjusts motion parameters without changing the trajectory geometry, making it suitable for scenarios with high path accuracy requirements, such as welding and spraying.

[0100] This solution avoids the risk of real-time control lag by predicting the stress at each point on the trajectory in advance. Without changing the geometry of the trajectory, it ensures that the bending moment that the tool can withstand is within the safety threshold, which not only improves the safety of robot operation, but also ensures the path accuracy and efficiency of welding, handling and other operations. It is a universal protection solution applicable to different tool types.

[0101] In some embodiments, the control unit 103 is configured to determine the operating rate of the robot and control the speed and acceleration of the tool according to the operating rate, including:

[0102] The control unit 103 is further configured to decompose the bending moment experienced by the tool to obtain a gravitational component and a motion component.

[0103] The bending moment borne by the tool is generated by both gravity (static load) and motion (dynamic load), with the gravity component M. g Caused by the tool's own weight, and related to its orientation (e.g., maximum when horizontal, zero when vertical); motion component M av Caused by centrifugal force and inertial force, it is related to velocity v and acceleration a. Through vector analysis, the total bending moment M is decomposed into gravitational and kinematic components, i.e.:

[0104]

[0105] Where, θ g Let θ be the angle between the gravity vector and the projection plane. av This is the angle between the resultant force vector of centrifugal force and inertial force and the projection plane. When adjusting the magnification, only the centrifugal force and inertial force are adjusted.

[0106] The control unit 103 is further configured to calculate the operating rate when the bending moment experienced by the tool does not exceed a preset threshold, based on a preset formula, the gravity component, and the motion component.

[0107] In some embodiments, the preset formula can calculate the operating rate when the bending moment experienced by the tool equals a preset threshold; the preset formula is:

[0108]

[0109] Where K is the operating ratio, M lim M is a preset threshold. g M is the gravitational component. av The motion component is referred to here.

[0110] Specifically, if the bending moment experienced by the tool is to be exactly equal to a preset threshold, then the bending moment after the magnification adjustment is M2 = M lim =M g +M av K2 That is, the operating ratio

[0111] The control unit 103 is further configured to multiply the estimated speed by the operating ratio to obtain a new estimated speed; and to multiply the estimated acceleration by the square of the operating ratio to obtain a new estimated acceleration.

[0112] The scaling factor adjusts the robot's operating rate, which is a parameter for a trajectory segment or the overall motion. Taking time-scaling-based scaling factor adjustment as an example: at 100% scaling factor, the original motion planning interpolation was 2ms, meaning interpolation points (absolute joint positions) were sent every 2ms; at 50% scaling factor, the time is scaled by 0.5, and every 2ms, the original 1ms interpolation points are sent. Therefore, the velocity in the entire planning segment becomes 0.5 times the original, and the acceleration becomes 0.5 * 0.5 = 0.25 times the original.

[0113] By altering the time distribution of the interpolation points, the overall motion velocity can be adjusted while maintaining the trajectory geometry. Specifically, if the original motion time is T, containing N interpolation points, then the time interval between each interpolation point is Δt1 = T / N; after time scaling, the motion time becomes T' = T / K, and the time interval between interpolation points becomes Δt2 = T' / N = T / (N·K) = Δt1 / K; velocity v = displacement / time, therefore the new velocity v2 = v1·K. Acceleration is the derivative of velocity with respect to time, i.e., a = dv / dt. When the time scaling is t' = t / K, the velocity becomes v' = v·K, then a' = a·K. 2 That is, the acceleration is proportional to the square of the multiplier K.

[0114] The control unit 103 is further configured to control the tool to move at a new estimated speed and a new estimated acceleration.

[0115] After the magnification adjustment, the motion components and the new centrifugal force are obtained based on the new predicted velocity and new predicted acceleration. New inertial force Thus, new motion components When the tool moves along a preset trajectory under new motion components, the bending moment it experiences will never exceed a threshold. This enables precise control of the force applied to the tool, distinguishes between static and dynamic load characteristics, avoids excessive deceleration due to misjudgment of gravity or overload risks caused by neglecting dynamic loads, and maximizes operational efficiency while ensuring safety.

[0116] Figure 4 This is a flowchart illustrating another embodiment of the robot control method of the present invention, as shown below. Figure 4 As shown, the method includes:

[0117] Step 1: Parse the motion commands set by the user to obtain the target position and various motion parameters.

[0118] Step 2: Using the parameters obtained in Step 1, perform pre-planning to obtain the predicted motion trajectory, velocity, and acceleration.

[0119] Step 3: Calculate the bending moment that the tool in the pre-planned design will bear.

[0120] Step 4: Determine whether the bending moment borne by the tool in the pre-planned program is greater than the tool bending moment limit. If the bending moment is greater than the bending moment limit, proceed to step 5; otherwise, directly use the trajectory from the pre-processing stage for execution.

[0121] Step 5: Perform magnification adjustment calculations and re-plan the motion to control the tool's operation. This ensures that the bending moment experienced by the end effector during robot movement remains within its tolerance range, preventing the end effector from bending or breaking due to excessive bending moment during use.

[0122] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0123] The technical solution of this invention pre-plans the motion trajectory of the robot's end effector based on the robot's operating parameters, determining the expected bending moment the tool will bear. When the expected bending moment exceeds a preset threshold, the robot's operating rate is determined, and the tool's speed and acceleration are controlled according to the operating rate to ensure that the bending moment experienced by the tool does not exceed the preset threshold. Thus, by calculating the bending moment experienced by the end effector in advance during the robot's motion planning process and adjusting the operating rate during actual movement, the bending moment experienced by the end effector during movement is guaranteed to be less than its bearing limit, preventing bending or even breakage of the tool, ensuring stable robot operation, and improving operational safety.

[0124] According to an embodiment of the present invention, a robot corresponding to a robot control device is also provided. This robot may include the robot control device described above.

[0125] Since the processing and functions implemented by the robot in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned device, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0126] The technical solution of this invention pre-plans the motion trajectory of the robot's end effector based on the robot's operating parameters, determining the expected bending moment the tool will bear. When the expected bending moment exceeds a preset threshold, the robot's operating rate is determined, and the tool's speed and acceleration are controlled according to the operating rate to ensure that the bending moment experienced by the tool does not exceed the preset threshold. Thus, by calculating the bending moment experienced by the end effector in advance during the robot's motion planning process and adjusting the operating rate during actual movement, the bending moment experienced by the end effector during movement is guaranteed to be less than its bearing limit, preventing bending or even breakage of the tool, ensuring stable robot operation, and improving operational safety.

[0127] According to an embodiment of the present invention, a storage medium corresponding to a robot control method is also provided, the storage medium including a stored program, wherein the program controls the device where the storage medium is located to execute the robot control method described above when it is executed.

[0128] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0129] The technical solution of this invention pre-plans the motion trajectory of the robot's end effector based on the robot's operating parameters, determining the expected bending moment the tool will bear. When the expected bending moment exceeds a preset threshold, the robot's operating rate is determined, and the tool's speed and acceleration are controlled according to the operating rate to ensure that the bending moment experienced by the tool does not exceed the preset threshold. Thus, by calculating the bending moment experienced by the end effector in advance during the robot's motion planning process and adjusting the operating rate during actual movement, the bending moment experienced by the end effector during movement is guaranteed to be less than its bearing limit, preventing bending or even breakage of the tool, ensuring stable robot operation, and improving operational safety.

[0130] According to an embodiment of the present invention, a computer program product corresponding to a robot control method is also provided. The computer program product includes a computer program that, when processed and executed, implements the steps of the robot control method described above.

[0131] Since the processing and functions implemented by the computer program product in this embodiment are basically corresponding to the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0132] The technical solution of this invention pre-plans the motion trajectory of the robot's end effector based on the robot's operating parameters, determining the expected bending moment the tool will bear. When the expected bending moment exceeds a preset threshold, the robot's operating rate is determined, and the tool's speed and acceleration are controlled according to the operating rate to ensure that the bending moment experienced by the tool does not exceed the preset threshold. Thus, by calculating the bending moment experienced by the end effector in advance during the robot's motion planning process and adjusting the operating rate during actual movement, the bending moment experienced by the end effector during movement is guaranteed to be less than its bearing limit, preventing bending or even breakage of the tool, ensuring stable robot operation, and improving operational safety.

[0133] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0134] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of the claims.

Claims

1. A method for controlling a robot, characterized in that, The robot's end effector is equipped with a tool; the method includes: Obtain the operating parameters of the robot; Based on the operating parameters, the motion trajectory of the tool is pre-planned, and the bending moment that the tool will bear is determined and denoted as the expected bending moment. When the expected bending moment is greater than a preset threshold, the operating rate of the robot is determined, and the speed and acceleration of the tool are controlled according to the operating rate to ensure that the bending moment experienced by the tool does not exceed the preset threshold. The process of pre-planning the motion trajectory of the tool based on the operating parameters and determining the bending moment that the tool will withstand includes: Based on the operating parameters, simulation planning interpolation is performed at fixed time intervals to calculate the estimated motion parameters for each interpolation point, including the estimated velocity and the estimated acceleration. Calculate the centrifugal force and inertial force that the tool will withstand based on the estimated motion parameters; The centrifugal force, the inertial force, and the gravity acting on the tool are vector-synthesized to obtain a three-dimensional composite force. The composite force in three-dimensional space is projected onto a plane perpendicular to the long axis of the tool to obtain the projected force; The product of the projected force and the tool length is determined as the bending moment that the tool will bear.

2. The robot control method according to claim 1, characterized in that, The long axis of the tool is the maximum extension axis through the center of mass of the tool.

3. The robot control method according to claim 1, characterized in that, The tool length is the maximum distance from the fixed end to the distal end of the tool.

4. The robot control method according to claim 1, characterized in that, Determining the operating rate of the robot, and controlling the speed and acceleration of the tool according to the operating rate, includes: The bending moment acting on the tool is decomposed into gravitational and kinematic components. Based on the preset formula, the gravity component, and the motion component, calculate the operating rate when the bending moment experienced by the tool does not exceed a preset threshold. Multiply the estimated speed by the operating ratio to obtain a new estimated speed; multiply the estimated acceleration by the square of the operating ratio to obtain a new estimated acceleration; Control the tool to move at the new estimated speed and the new estimated acceleration.

5. The robot control method according to claim 4, characterized in that, The preset formula can calculate the operating rate when the bending moment experienced by the tool equals a preset threshold; the preset formula is: ； Where K is the operating ratio, M lim M is a preset threshold. g M is the gravitational component. av The motion component is referred to here.

6. A control device for a robot, characterized in that, The robot's end effector is equipped with a tool; the device includes: The acquisition unit is configured to acquire the operating parameters of the robot; The pre-planning unit is configured to pre-plan the motion trajectory of the tool based on the operating parameters, and determine the bending moment that the tool will bear, denoted as the expected bending moment; The control unit is configured to determine the operating rate of the robot when the expected bending moment is greater than a preset threshold, and control the speed and acceleration of the tool according to the operating rate so that the bending moment on the tool does not exceed the preset threshold. The pre-planning unit, based on the operating parameters, pre-plans the motion trajectory of the tool and determines the bending moment that the tool will withstand, including: Based on the operating parameters, simulation planning interpolation is performed at fixed time intervals to calculate the estimated motion parameters for each interpolation point, including the estimated velocity and the estimated acceleration. Calculate the centrifugal force and inertial force that the tool will withstand based on the estimated motion parameters; The centrifugal force, the inertial force, and the gravity acting on the tool are vector-synthesized to obtain a three-dimensional composite force. The composite force in three-dimensional space is projected onto a plane perpendicular to the long axis of the tool to obtain the projected force; The product of the projected force and the tool length is determined as the bending moment that the tool will bear.

7. A robot, characterized in that, include: The robot control device as described in claim 6.

8. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the robot control method according to any one of claims 1 to 5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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