A control system of a multi-functional punch press three-axis robot

Abstract

The present application relates to the field of intelligent manufacturing, and more particularly to a control system of a multifunctional punch press three-axis manipulator, comprising: a data processing module comprising a sensor array for collecting operation data of the multifunctional punch press three-axis manipulator and operation cycle of the punch press; a synchronous control module comprising a synchronous unit for determining a trigger node of action execution of the three-axis manipulator according to the operation cycle of the punch press; a clamping determination module for determining whether the clamping stability of the three-axis manipulator meets the requirements according to the relative slip amplitude of the workpiece during clamping; a torque compensation module for determining whether to construct an adaptive torque compensation mechanism according to the overage of workpiece clamping positioning; and a trigger offset adjustment module for determining the trigger offset compensation amount of action execution of the three-axis manipulator according to the fluctuation amplitude of the clamping force of the workpiece per unit time. The present application improves the clamping stability of the three-axis manipulator.

Description

Technical Field

[0001] This invention relates to the field of intelligent manufacturing, and in particular to a control system for a multifunctional three-axis manipulator for punch presses. Background Technology

[0002] Against the backdrop of rapid development in stamping automation and intelligent manufacturing, multi-functional three-axis manipulators for punch presses have become crucial execution units for achieving automatic workpiece loading and unloading, process seamless integration, and cycle time improvement. Existing three-axis manipulator control systems primarily focus on trajectory planning and position control, paying insufficient attention to the mechanical state during the clamping process. Fluctuations in the friction coefficient between the clamping end and the workpiece can easily lead to minute slippage or even clamping instability, thus affecting workpiece positioning accuracy and stamping consistency. Furthermore, existing control methods often employ fixed parameters or simple feedback adjustment mechanisms, lacking the dynamic adaptability to the coupled effects of multiple factors under complex working conditions, making it difficult to achieve an effective balance between clamping stability and real-time response. Therefore, there is an urgent need for a control system for multi-functional three-axis manipulators for punch presses that integrates state monitoring and adaptive control strategies to achieve real-time assessment and dynamic optimization of clamping stability, thereby improving the stability and machining accuracy of the stamping process.

[0003] Chinese Patent Publication No. CN109129493A discloses a three-axis robotic arm control system, comprising: motion axes, including a first motion axis, a second motion axis, a third motion axis, and an actuator. The first motion axis, second motion axis, third motion axis, and actuator are connected sequentially. The first motion axis is mounted on a base. The second motion axis can move along the direction of the first motion axis, the third motion axis can move along the direction of the second motion axis, and the actuator can move along the direction of the third motion axis. The direction of motion of the actuator is orthogonal to the plane in which the motion of the third motion axis occurs. Therefore, the three-axis robotic arm control system suffers from insufficient clamping stability due to timing deviations in the synchronous triggering of the various drive signals during transmission and execution, and lag and deviation between the actuator's action and the actual force state of the workpiece. Summary of the Invention

[0004] Therefore, the present invention provides a control system for a multi-functional punch press three-axis robot, which overcomes the problem of insufficient clamping stability of the three-axis robot in the prior art due to the synchronous triggering timing deviation of each drive signal during transmission and execution, and the lag and deviation between the action of the actuator and the actual force state of the workpiece.

[0005] To achieve the above objectives, the present invention provides a control system for a multifunctional three-axis manipulator for punch presses, comprising:

[0006] The data processing module includes a sensor array for collecting the operation data of the three-axis robot of the multi-functional punch press and the operation cycle of the punch press, and a preprocessing unit connected to the sensor array for preprocessing the operation data to obtain the working condition characteristics.

[0007] The synchronization control module, which is connected to the data processing module, includes a synchronization unit for determining the trigger node for the three-axis robot to perform actions based on the running cycle of the punch press, a motion control unit connected to the synchronization unit for constructing the motion trajectory of the three-axis robot at the trigger node based on the working condition characteristics to output linkage control commands, and a clamping control unit connected to the motion control unit for determining the workpiece clamping strategy based on the linkage control commands.

[0008] A stamping execution module, which is connected to the synchronous control module, is used to execute the linkage control command and the clamping strategy according to the three-axis robot to complete the stamping process of the workpiece;

[0009] The clamping determination module, which is connected to the stamping execution module, is used to determine whether the clamping stability of the three-axis robot meets the requirements based on the relative sliding amplitude of the workpiece during the clamping process.

[0010] A torque compensation module, which is connected to the stamping execution module and the clamping determination module respectively, is used to determine whether to construct an adaptive torque compensation mechanism based on the workpiece clamping and positioning deviation.

[0011] The trigger offset adjustment module is connected to the synchronization control module and the torque compensation module respectively, and is used to determine the trigger offset compensation amount for the three-axis robot's actions based on the fluctuation range of the clamping force on the workpiece per unit time.

[0012] Furthermore, the clamping determination module determines that the clamping stability of the three-axis robot meets the requirements when the relative sliding amplitude of the workpiece during the clamping process is less than or equal to the preset sliding amplitude.

[0013] The clamping determination module determines that the clamping stability of the three-axis robot does not meet the requirements when the relative sliding amplitude of the workpiece during the clamping process is greater than the preset sliding amplitude.

[0014] Furthermore, in response to the condition that the clamping stability of the three-axis robot does not meet the requirements, the torque compensation module determines whether the vibration resistance stability of the three-axis robot meets the requirements based on the deviation of the workpiece clamping and positioning.

[0015] Furthermore, the torque compensation module responds to the workpiece clamping and positioning deviation being less than or equal to a preset first deviation, thus determining that the vibration resistance stability of the three-axis robot meets the requirements.

[0016] The torque compensation module responds to the workpiece clamping and positioning deviation being greater than the preset first deviation, and determines that the vibration stability of the three-axis robot does not meet the requirements.

[0017] Furthermore, the torque compensation module constructs an adaptive torque compensation mechanism in response to the workpiece clamping and positioning deviation being greater than the preset first deviation and less than or equal to the preset second deviation.

[0018] Furthermore, in response to the workpiece clamping and positioning deviation being greater than the preset second deviation, the torque compensation module initially determines that the stability of the clamping friction coefficient does not meet the requirements, and determines whether the stability of the clamping friction coefficient meets the requirements based on the fluctuation range of the clamping force on the workpiece per unit time.

[0019] Furthermore, an adaptive torque compensation mechanism is constructed, including:

[0020] The torque compensation module is used to construct a dynamic model of the clamping end based on the operating data of the three-axis manipulator of the multi-functional punch press;

[0021] The clamping end dynamic model is used to calculate the dynamic compensation clamping force based on the clamping end vibration signal collected by the sensor array, and to superimpose the dynamic compensation clamping force and the initial clamping force to output the total output force;

[0022] The torque compensation module is used to convert the total output force into corresponding drive parameters according to the type of gripper actuator.

[0023] The torque compensation module is used to output the driving parameters to the corresponding actuator to achieve adaptive control of the clamping force.

[0024] Furthermore, in response to the condition that the workpiece clamping and positioning deviation is greater than the preset second deviation, the trigger offset adjustment module determines whether the stability of the clamping friction coefficient meets the requirements based on the fluctuation range of the clamping force on the workpiece per unit time.

[0025] Furthermore, the trigger offset adjustment module responds to the fluctuation amplitude of the clamping force on the workpiece per unit time being less than or equal to the preset fluctuation amplitude, thus determining that the stability of the clamping friction coefficient meets the requirements.

[0026] The trigger offset adjustment module responds to the fact that the fluctuation range of the clamping force on the workpiece within the unit time is greater than the preset fluctuation range, determines that the stability of the clamping friction coefficient does not meet the requirements, and reduces the trigger offset compensation amount of the three-axis robot's action execution.

[0027] Furthermore, the reduction in the trigger offset compensation amount for the three-axis robot's actions is determined by the difference between the fluctuation amplitude of the clamping force on the workpiece per unit time and the preset fluctuation amplitude.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: The system of the present invention, by setting up a data processing module, a synchronous control module, a stamping execution module, a clamping judgment module, a torque compensation module, and a trigger offset adjustment module, determines whether the clamping stability of the three-axis robot meets the requirements based on the relative slippage amplitude of the workpiece during the clamping process. Since the workpiece is subjected to impact force and inertia during the loading and unloading phases of the clamping process, uneven clamping force distribution or insufficient friction conditions can cause minute slippage that gradually accumulates and amplifies. By determining the clamping stability of the three-axis robot, the constraint capability of the clamping state on the workpiece can be quantified, and potential clamping instability risks can be identified in a timely manner. The system determines whether to construct an adaptive torque compensation mechanism based on the workpiece clamping and positioning deviation. Since the workpiece is subjected to vibration interference and inertial impact during the clamping and movement phases of the workpiece handling operation, if the mechanical... Insufficient response and lag in adjustment of the robot arm to vibration disturbances lead to workpiece positioning errors and imbalances in clamping force distribution. By constructing a torque compensation mechanism, pre-compensation can be applied to the execution joints of the robot arm, allowing the control response to offset the deviations caused by vibration in advance, thereby improving workpiece positioning accuracy and processing consistency. The trigger offset compensation amount of the three-axis robot arm's motion execution is adjusted according to the fluctuation range of the clamping force on the workpiece per unit time. Due to the presence of oil contamination in stamping operations, the contact friction coefficient between the workpiece and the clamping end is prone to random fluctuations, resulting in uncertainty in the clamping response and causing the clamping adjustment to lag behind the actual sliding state changes. By reducing the trigger offset compensation amount of the three-axis robot arm's motion execution, the timeliness of the control response can be improved, making the clamping adjustment more in line with real-time working condition changes. Even under frictional instability conditions, the effective constraint of the clamping force is maintained, thus improving the clamping stability of the three-axis robot arm.

[0029] Furthermore, the system described in this invention determines whether the clamping stability of the three-axis robot meets the requirements by setting a preset slip amplitude. During the clamping process, the workpiece is subjected to impact force and inertia during the loading and unloading phases. Uneven clamping force distribution or insufficient friction conditions will cause small slippage, which will gradually accumulate and amplify. By determining the clamping stability of the three-axis robot, the constraint ability of the clamping state on the workpiece can be quantified, and potential clamping instability risks can be identified in a timely manner, thereby further improving the clamping stability of the three-axis robot.

[0030] Furthermore, the system of the present invention determines whether to construct an adaptive torque compensation mechanism by setting a preset first deviation amount and a preset second deviation amount. Since the workpiece is subjected to vibration interference and inertial impact during the workpiece handling process, if the robot arm's response to vibration disturbance is insufficient and its adjustment is lagging, the workpiece positioning position will be out of tolerance, causing an imbalance in the clamping force distribution. By constructing a torque compensation mechanism, pre-compensation can be applied to the execution joints of the robot arm, so that the control response can offset the deviation caused by vibration in advance, improve the workpiece positioning accuracy and processing consistency, and further improve the clamping stability of the three-axis robot arm.

[0031] Furthermore, the system described in this invention adjusts the trigger offset compensation amount for the three-axis robot's actions by setting a preset fluctuation amplitude. Due to the presence of oil contamination in stamping operations, the contact friction coefficient between the workpiece and the clamping end is prone to random fluctuations, resulting in uncertainty in the clamping response. This causes the clamping adjustment to lag behind the actual sliding state changes. By reducing the trigger offset compensation amount for the three-axis robot's actions, the timeliness of the control response can be improved, making the clamping adjustment more closely match real-time working condition changes. Even under frictional instability conditions, the effective constraint of the clamping force is maintained, further improving the clamping stability of the three-axis robot. Attached Figure Description

[0032] Figure 1 This is an overall structural block diagram of the control system of the multifunctional punch press three-axis robot according to an embodiment of the present invention;

[0033] Figure 2 The following is a flowchart illustrating the process by which the control system of the multi-functional punch press three-axis robot determines whether the clamping stability of the three-axis robot meets the requirements in an embodiment of the present invention.

[0034] Figure 3 A flowchart illustrating the process of determining whether to construct an adaptive torque compensation mechanism in the control system of the multi-functional punch press three-axis robot of this invention.

[0035] Figure 4 The flowchart illustrates the process by which the control system of the multi-functional punch press three-axis robot determines the trigger offset compensation amount for the execution of the three-axis robot's actions, according to an embodiment of the present invention. Detailed Implementation

[0036] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0037] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0038] Please see Figure 1 As shown, it is an overall structural block diagram of the control system of the multi-functional punch press three-axis robot according to an embodiment of the present invention.

[0039] The present invention provides a control system for a multifunctional three-axis manipulator for punch presses, comprising:

[0040] The data processing module includes a sensor array for collecting the operation data of the three-axis robot of the multi-functional punch press and the operation cycle of the punch press, and a preprocessing unit connected to the sensor array for preprocessing the operation data to obtain the working condition characteristics.

[0041] The synchronization control module, which is connected to the data processing module, includes a synchronization unit for determining the trigger node for the three-axis robot to perform actions based on the running cycle of the punch press, a motion control unit connected to the synchronization unit for constructing the motion trajectory of the three-axis robot at the trigger node based on the working condition characteristics to output linkage control commands, and a clamping control unit connected to the motion control unit for determining the workpiece clamping strategy based on the linkage control commands.

[0042] A stamping execution module, which is connected to the synchronous control module, is used to execute the linkage control command and the clamping strategy according to the three-axis robot to complete the stamping process of the workpiece;

[0043] The clamping determination module, which is connected to the stamping execution module, is used to determine whether the clamping stability of the three-axis robot meets the requirements based on the relative sliding amplitude of the workpiece during the clamping process.

[0044] A torque compensation module, which is connected to the stamping execution module and the clamping determination module respectively, is used to determine whether to construct an adaptive torque compensation mechanism based on the workpiece clamping and positioning deviation.

[0045] The trigger offset adjustment module is connected to the synchronization control module and the torque compensation module respectively, and is used to determine the trigger offset compensation amount for the three-axis robot's actions based on the fluctuation range of the clamping force on the workpiece per unit time.

[0046] Specifically, the operating data of a three-axis robot includes gripping status data, servo drive data, and motion status data.

[0047] Specifically, the sensor array includes a vacuum pressure sensor, a triaxial accelerometer, and a laser displacement sensor.

[0048] Specifically, preprocessing includes cleaning, denoising, normalization, and feature extraction.

[0049] Specifically, the operating characteristics include clamping force fluctuation rate, motor load rate, and workpiece positioning and stabilization time.

[0050] Specifically, the operating cycle of a punch press is the time interval between two adjacent punching cycles.

[0051] Specifically, the process of determining the trigger node for the robot's actions based on the running cycle of the punch press involves extracting the top dead point or bottom dead point time from the periodic signal of the punch press's running cycle, and then compensating for the trigger time by advancing or delaying it in conjunction with the robot's response delay to obtain the corrected trigger node.

[0052] Specifically, the process of constructing the motion trajectory of the three-axis robot at the trigger node based on the working condition characteristics and outputting linkage control commands involves acquiring the working condition characteristics of the robot in real time at the corrected trigger node, comparing and judging the working condition characteristics, determining the key points of the target trajectory and the corresponding time parameters based on the judgment results, generating a continuous motion trajectory through an interpolation algorithm, performing trigger offset compensation at the trajectory start time, selecting the corresponding robot motion parameters based on the offset compensation, and outputting linkage control commands.

[0053] Specifically, the linkage control command is a set of multi-parameter controls used to synchronize the robot arm's movements with the punch press cycle.

[0054] Specifically, the workpiece clamping strategies include vacuum adsorption modulation strategy, synchronous waiting strategy, and adaptive clamping strategy.

[0055] Specifically, the trigger offset compensation amount for the three-axis robot's motion execution is the compensation amount used to correct the deviation between the robot's target position and the actual starting position when the three-axis robot performs the motion.

[0056] In implementation, the system of this invention, by setting up a data processing module, a synchronization control module, a stamping execution module, a clamping judgment module, a torque compensation module, and a trigger offset adjustment module, determines whether the clamping stability of the three-axis robot meets the requirements based on the relative slippage amplitude of the workpiece during clamping. Since the workpiece is subjected to impact forces and inertia during the loading and unloading phases of clamping, uneven clamping force distribution or insufficient friction conditions can cause minute slippage that gradually accumulates and amplifies. By determining the clamping stability of the three-axis robot, the constraint capability of the clamping state on the workpiece can be quantified, and potential clamping instability risks can be identified in a timely manner. The system determines whether to construct an adaptive torque compensation mechanism based on the workpiece clamping and positioning deviation. Since the workpiece is subjected to vibration interference and inertial impact during the clamping and movement phases of workpiece handling, if the robot's response to vibration disturbances is insufficient... Insufficient response and lag in adjustment lead to workpiece positioning errors and an imbalance in clamping force distribution. By constructing a torque compensation mechanism, pre-compensation can be applied to the actuator joints of the robot, allowing the control response to offset the deviation caused by vibration in advance, thereby improving workpiece positioning accuracy and processing consistency. The trigger offset compensation amount of the three-axis robot's motion execution is adjusted according to the fluctuation range of the clamping force on the workpiece per unit time. Due to the presence of oil contamination in stamping operations, the contact friction coefficient between the workpiece and the clamping end is prone to random fluctuations, resulting in uncertainty in the clamping response and causing the clamping adjustment to lag behind the actual sliding state changes. By reducing the trigger offset compensation amount of the three-axis robot's motion execution, the timeliness of the control response can be improved, making the clamping adjustment more in line with real-time working condition changes. Even under frictional instability conditions, the effective constraint of the clamping force is maintained, thus improving the clamping stability of the three-axis robot.

[0057] Please continue reading. Figure 2 As shown, it is a logic flowchart of the process by which the control system of the multi-functional punch press three-axis robot in an embodiment of the present invention determines whether the clamping stability of the three-axis robot meets the requirements.

[0058] Specifically, the clamping determination module determines whether the clamping stability of the three-axis robot meets the requirements based on the relative sliding amplitude of the workpiece during the clamping process.

[0059] Specifically, the clamping determination module determines that the clamping stability of the three-axis robot meets the requirements when the relative sliding amplitude of the workpiece during the clamping process is less than or equal to the preset sliding amplitude.

[0060] The clamping determination module determines that the clamping stability of the three-axis robot does not meet the requirements when the relative sliding amplitude of the workpiece during the clamping process is greater than the preset sliding amplitude.

[0061] Understandably, in the control system of a three-axis robot for a multi-functional punch press, quantifying the clamping stability of the three-axis robot using a preset sliding amplitude involves transforming the abstract clamping stability of the three-axis robot into a quantifiable adjustment range. By comparing this range with a preset fluctuation threshold, it is determined whether the scheduling maintains the expected stability during actual execution. The preset sliding amplitude serves as the dividing line for distinguishing whether the clamping stability of the three-axis robot meets the requirements. The preset sliding amplitude can be set according to actual working conditions. The setting of the preset sliding amplitude aims to ensure the clamping stability and practicality of the three-axis robot. Optionally, the preset sliding amplitude is determined through a limited number of tests by evaluating the clamping effect of different optimized adjustment amplitudes on the three-axis robot. The determined preset sliding amplitude should satisfy the condition that it is neither too small nor will it cause excessive interference to the clamping process of the three-axis robot. For example, the preset sliding amplitude is generally selected in the range of [0.01mm, 0.05mm].

[0062] Preferably, the preset sliding amplitude is 0.03 mm.

[0063] Specifically, the relative slippage of the workpiece during the clamping process is the displacement distance of the workpiece relative to the gripper when the workpiece is disturbed by the robot arm.

[0064] Specifically, the disturbances include vibration, inertial forces, and clamping start-stop impacts.

[0065] In practice, the system described in this invention determines whether the clamping stability of the three-axis robot meets the requirements by setting a preset slip amplitude. During the clamping process, the workpiece is subjected to impact force and inertia during the loading and unloading phases. Uneven clamping force distribution or insufficient friction conditions can cause small slippages that gradually accumulate and amplify. By determining the clamping stability of the three-axis robot, the constraint capability of the clamping state on the workpiece can be quantified, and potential clamping instability risks can be identified in a timely manner, further improving the clamping stability of the three-axis robot.

[0066] Please continue reading. Figure 3 As shown, it is a logical flowchart of the process of determining whether to construct an adaptive torque compensation mechanism in the control system of the multi-functional punch press three-axis robot of the present invention.

[0067] Specifically, the control system of the three-axis robot for a multi-functional punch press is characterized in that, in response to the condition that the clamping stability of the three-axis robot does not meet the requirements, the torque compensation module determines whether the vibration resistance stability of the three-axis robot meets the requirements based on the deviation of the workpiece clamping and positioning.

[0068] Specifically, the torque compensation module responds to the workpiece clamping and positioning deviation being less than or equal to a preset first deviation, thus determining that the vibration resistance stability of the three-axis robot meets the requirements.

[0069] The torque compensation module responds to the workpiece clamping and positioning deviation being greater than the preset first deviation, and determines that the vibration stability of the three-axis robot does not meet the requirements.

[0070] Specifically, the torque compensation module constructs an adaptive torque compensation mechanism in response to the workpiece clamping and positioning deviation being greater than the preset first deviation and less than or equal to the preset second deviation.

[0071] Specifically, the torque compensation module responds to the workpiece clamping and positioning deviation being greater than the preset second deviation, initially determining that the stability of the clamping friction coefficient does not meet the requirements, and determines whether the stability of the clamping friction coefficient meets the requirements based on the fluctuation range of the clamping force on the workpiece per unit time.

[0072] It is understandable that the preset first deviation is less than the preset second deviation, and the three intervals divided by the preset first and second deviations correspond to three different situations:

[0073] The first interval is when the workpiece clamping and positioning deviation is less than or equal to the preset first deviation, which corresponds to the situation where the vibration stability of the three-axis robot meets the requirements.

[0074] The second range is when the workpiece clamping and positioning deviation is greater than the preset first deviation and less than or equal to the preset second deviation. The corresponding situation is: during the workpiece handling operation, the workpiece will be subject to vibration interference and inertial impact during the clamping and moving stages. If the robot arm's response to vibration disturbance is insufficient and its adjustment is lagging, the workpiece positioning deviation will cause an imbalance in the clamping force distribution. At this time, an adaptive torque compensation mechanism needs to be constructed.

[0075] The third interval is when the workpiece clamping and positioning deviation is greater than the preset second deviation. The corresponding situation is: due to the presence of oil stains in the stamping operation, the contact friction coefficient between the workpiece and the clamping end is prone to random fluctuations, resulting in uncertainty in the clamping response, causing the clamping adjustment to lag behind the actual sliding state change.

[0076] Understandably, in the control system of a three-axis robot for a multi-functional punch press, the vibration resistance stability of the robot is characterized by preset first and second tolerance values. The core logic is to quantify the vibration resistance stability of the robot into a quantifiable tolerance range. By distinguishing the different ranges into which the tolerance falls, it is determined whether the anti-interference performance of the monitoring system meets the requirements during the robot's vibration operation. The preset first and second tolerance values ​​can be set according to actual working conditions. The setting of the preset first and second tolerance values ​​aims to ensure the clamping stability and practicality of the three-axis robot. Optionally, the preset first and second tolerance values ​​are determined through a limited number of tests by evaluating the clamping effect of different tolerance schemes on the three-axis robot. The determined preset first and second tolerance values ​​should satisfy the condition that they are neither too small nor cause excessive interference to the clamping process of the three-axis robot. For example, the preset first deviation amount is generally selected in the range of [0.01mm, 0.03mm], and the preset first deviation amount and preset second deviation amount are generally selected in the range of [0.07mm, 0.09mm].

[0077] Preferably, the first tolerance is 0.02 mm, and the second tolerance is 0.08 mm.

[0078] Specifically, the workpiece clamping and positioning deviation is the distance between the actual positioning center of the workpiece and the target positioning center when the robot clamps the workpiece and positions it to the target position.

[0079] Specifically, constructing an adaptive torque compensation mechanism includes:

[0080] The torque compensation module is used to construct a dynamic model of the clamping end based on the operating data of the three-axis manipulator of the multi-functional punch press;

[0081] The clamping end dynamic model is used to calculate the dynamic compensation clamping force based on the clamping end vibration signal collected by the sensor array, and to superimpose the dynamic compensation clamping force and the initial clamping force to output the total output force;

[0082] The torque compensation module is used to convert the total output force into corresponding drive parameters according to the type of gripper actuator.

[0083] The torque compensation module is used to output the driving parameters to the corresponding actuator to achieve adaptive control of the clamping force.

[0084] Specifically, the clamping end dynamics model is the contact stiffness model between the gripper and the workpiece.

[0085] Specifically, the process of constructing a dynamic model of the gripping end based on the operating data of the three-axis robot of a multi-functional punch press involves treating the contact between the gripper and the workpiece as an elastic-damped system:

[0086]

[0087] Where m is the total mass of the workpiece and the movable part of the gripper;

[0088] x is the relative displacement between the workpiece and the gripper;

[0089] x' is the relative displacement velocity between the workpiece and the gripper;

[0090] x'' is the acceleration of the workpiece relative to the gripper;

[0091] c is the damping coefficient at the contact point between the workpiece and the gripper;

[0092] k is the contact stiffness of the clamping end;

[0093] F1 is the external disturbance force of the clamping action;

[0094] F2 is the output force for torque compensation.

[0095] Specifically, the process of calculating the dynamic compensation clamping force based on the vibration signal of the clamping end collected by the sensor array is as follows:

[0096]

[0097] Where Fcomp(t) is the dynamic compensation force used to suppress vibration;

[0098] K a It is the acceleration feedforward coefficient, used to adjust the compensation strength of the inertial force generated by the absolute acceleration of the gripper;

[0099] a(t) is the absolute acceleration of the gripper;

[0100] K v This is the damping compensation coefficient, used to adjust the damping strength at the contact point between the workpiece and the gripper.

[0101] x'(t) is the estimated real-time relative velocity of the gripper;

[0102] K x This is the stiffness compensation coefficient, used to control the elastic compensation strength of the gripper;

[0103] x(t) is the real-time relative displacement between the workpiece and the gripper;

[0104] Specifically, the dynamic compensation clamping force and the initial clamping force are superimposed to output the total output force:

[0105] F s =F p +Fcomp(t)

[0106] Among them, F s This is the total output force;

[0107] F p This is the initial clamping force.

[0108] Specifically, converting the total output force into corresponding drive parameters based on the gripper actuator type includes:

[0109] For electromagnetic adsorption grippers, the total output force is converted into a target current;

[0110] For vacuum adsorption grippers, the total output force is converted into the target vacuum level.

[0111] Specifically, for electromagnetic adsorption grippers, the process of converting the total output force into a target current is as follows: the target adsorption force is obtained based on the total output force, and the target current is obtained by substituting the target adsorption force into the electromagnetic adsorption force based on the correspondence between the electromagnetic adsorption force, the current, and the air gap.

[0112] Specifically, in this embodiment of the invention, the iron core of the electromagnetic adsorption gripper is in the non-magnetic saturation working range.

[0113] Specifically, the relationship between the electromagnetic attraction force, current, and air gap is as follows:

[0114]

[0115] Among them, F m It is an electromagnetic attraction force;

[0116] K m The equivalent magnetic force coefficient obtained through calibration;

[0117] I represents the operating current;

[0118] δ represents the real-time air gap between the electromagnetic adsorption gripper and the workpiece;

[0119] δ0 is the equivalent zero air gap obtained through calibration.

[0120] Specifically, the equivalent magnetic force coefficient obtained through calibration is determined by applying driving current step by step and measuring the corresponding adsorption force under fixed air gap conditions. Based on the relationship that the electromagnetic adsorption force is proportional to the square of the current, the measurement data is curve-fitted to obtain the proportionality coefficient between the adsorption force and the square of the current, and the equivalent magnetic force coefficient is determined.

[0121] Specifically, the equivalent zero air gap obtained through calibration is obtained by constructing a relationship inversely proportional to the square of the air gap based on multiple sets of experimental data of known air gaps and corresponding adsorption forces and currents, fitting and correcting the relationship to compensate for deviations and obtain the equivalent zero air gap.

[0122] Specifically, the target current is obtained by substituting the target adsorption force into the electromagnetic adsorption force:

[0123]

[0124] Specifically, for vacuum adsorption grippers, the process of converting the total output force into the target vacuum degree is as follows: the target adsorption force is obtained based on the total output force, and the target vacuum pressure difference is obtained by substituting the target adsorption force into the vacuum adsorption force based on the correspondence between the vacuum adsorption force and the vacuum pressure difference.

[0125] Specifically, the relationship between vacuum adsorption force and vacuum pressure difference is as follows:

[0126]

[0127] Among them, F v It is the vacuum adsorption force;

[0128] ΔP is the vacuum pressure difference;

[0129] A represents the actual adsorption contact area between the vacuum suction cup and the workpiece.

[0130] Specifically, the target vacuum pressure difference is obtained by substituting the target adsorption force into the vacuum adsorption force solution:

[0131]

[0132] In practice, the system of the present invention determines whether to construct an adaptive torque compensation mechanism by setting a preset first deviation amount and a preset second deviation amount. During the workpiece handling process, the workpiece will be subject to vibration interference and inertial impact during the clamping and moving stages. If the robot arm's response to vibration disturbance is insufficient or its adjustment is lagging, the workpiece positioning will be out of tolerance, causing an imbalance in the clamping force distribution. By constructing a torque compensation mechanism, pre-compensation can be applied to the robot arm's execution joints, so that the control response can offset the deviation caused by vibration in advance, improve the workpiece positioning accuracy and processing consistency, and further improve the clamping stability of the three-axis robot arm.

[0133] Please continue reading. Figure 4 The diagram shown is a logic flowchart illustrating the process by which the control system of the multi-functional punch press three-axis robot determines the trigger offset compensation amount for the execution of the three-axis robot's actions, according to an embodiment of the present invention.

[0134] Specifically, the trigger offset adjustment module, in response to the condition that the workpiece clamping and positioning deviation is greater than the preset second deviation, determines whether the stability of the clamping friction coefficient meets the requirements based on the fluctuation range of the clamping force on the workpiece per unit time.

[0135] Specifically, the trigger offset adjustment module responds to the fluctuation amplitude of the clamping force on the workpiece per unit time being less than or equal to the preset fluctuation amplitude, thus determining that the stability of the clamping friction coefficient meets the requirements.

[0136] The trigger offset adjustment module responds to the fact that the fluctuation range of the clamping force on the workpiece within the unit time is greater than the preset fluctuation range, determines that the stability of the clamping friction coefficient does not meet the requirements, and reduces the trigger offset compensation amount of the three-axis robot's action execution.

[0137] The reduction in the trigger offset compensation amount for the three-axis robot's actions is determined by the difference between the fluctuation range of the clamping force on the workpiece per unit time and the preset fluctuation range.

[0138] It is understandable that the two preset fluctuation ranges correspond to two different scenarios:

[0139] The first interval is when the fluctuation range of the clamping force on the workpiece per unit time is less than or equal to the preset fluctuation range. The corresponding situation is: the stability of the clamping friction coefficient meets the requirements.

[0140] The second interval is when the fluctuation range of the clamping force on the workpiece per unit time is greater than the preset fluctuation range. The corresponding situation is: due to the presence of oil stains in the stamping operation, the contact friction coefficient between the workpiece and the clamping end is prone to random fluctuations, resulting in uncertainty in the clamping response. This causes the clamping adjustment to lag behind the actual sliding state change. In this case, it is necessary to reduce the trigger offset compensation amount of the three-axis robot's action execution.

[0141] Understandably, in the control system of a three-axis robot for a multi-functional punch press, the core logic of using a preset fluctuation amplitude to characterize the stability of the clamping friction coefficient is to quantify the degree of fluctuation of the clamping friction coefficient into a quantifiable range of values. By distinguishing whether the fluctuation amplitude of the clamping force on the workpiece per unit time exceeds the preset fluctuation amplitude, it is determined whether the clamping friction coefficient remains stable. The preset fluctuation amplitude can be set according to the actual working conditions. The setting of the preset fluctuation amplitude aims to ensure the clamping stability and practicality of the three-axis robot. Optionally, the preset fluctuation amplitude is determined through a limited number of tests by evaluating the clamping effect of different resource conflict rates on the three-axis robot. The determined preset fluctuation amplitude should satisfy the condition that it is neither too small nor too large to cause excessive interference to the clamping process of the three-axis robot. For example, the preset fluctuation amplitude is generally selected in the range of [4%, 6%].

[0142] Preferably, the preset fluctuation range is 5% in this preferred embodiment.

[0143] Specifically, the fluctuation range of the clamping force on the workpiece per unit time is the ratio of the difference between the maximum and minimum clamping forces of the workpiece held by the clamping end per unit time to the average clamping force.

[0144] Specifically, the reduction in the trigger offset compensation amount for the three-axis robot's actions is determined by the difference between the fluctuation range of the clamping force on the workpiece per unit time and the preset fluctuation range.

[0145] Specifically, when the difference between the fluctuation range of the clamping force on the workpiece per unit time and the preset fluctuation range is within 0.5%, the trigger offset compensation amount for the three-axis robot's motion execution is reduced to 0.9 times the original value. When the difference between the fluctuation range of the clamping force on the workpiece per unit time and the preset fluctuation range exceeds 0.5%, the trigger offset compensation amount for the three-axis robot's motion execution is reduced by 0.001 mm for every 0.2% increase beyond the original value, in addition to the reduction to 0.9 times the original value. For example, when the difference between the fluctuation range of the clamping force on the workpiece per unit time and the preset fluctuation range is 0.9%, the current trigger offset compensation amount for the three-axis robot's motion execution is 0.05 mm. The reduced trigger offset compensation amount for the three-axis robot's motion execution is 0.05 × 0.9 - 0.001 × 2 = 0.043 mm.

[0146] In practice, the system described in this invention adjusts the trigger offset compensation amount for the three-axis robot's actions by setting a preset fluctuation amplitude. Due to the presence of oil contamination in stamping operations, the contact friction coefficient between the workpiece and the clamping end is prone to random fluctuations, resulting in uncertainty in the clamping response. This causes the clamping adjustment to lag behind the actual sliding state changes. By reducing the trigger offset compensation amount for the three-axis robot's actions, the timeliness of the control response can be improved, making the clamping adjustment more closely match real-time working condition changes. Even under frictional instability conditions, the effective constraint of the clamping force is maintained, further improving the clamping stability of the three-axis robot.

[0147] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A control system for a multi-functional three-axis manipulator for a punch press, characterized in that, include: The data processing module includes a sensor array for collecting the operation data of the three-axis robot of the multi-functional punch press and the operation cycle of the punch press, and a preprocessing unit connected to the sensor array for preprocessing the operation data to obtain the working condition characteristics. The synchronization control module, which is connected to the data processing module, includes a synchronization unit for determining the trigger node for the three-axis robot to perform actions based on the running cycle of the punch press, a motion control unit connected to the synchronization unit for constructing the motion trajectory of the three-axis robot at the trigger node based on the working condition characteristics to output linkage control commands, and a clamping control unit connected to the motion control unit for determining the workpiece clamping strategy based on the linkage control commands. A stamping execution module, which is connected to the synchronous control module, is used to execute the linkage control command and the clamping strategy according to the three-axis robot to complete the stamping process of the workpiece; The clamping determination module, which is connected to the stamping execution module, is used to determine whether the clamping stability of the three-axis robot meets the requirements based on the relative sliding amplitude of the workpiece during the clamping process. A torque compensation module, which is connected to the stamping execution module and the clamping determination module respectively, is used to determine whether to construct an adaptive torque compensation mechanism based on the workpiece clamping and positioning deviation. The trigger offset adjustment module is connected to the synchronization control module and the torque compensation module respectively, and is used to determine the trigger offset compensation amount for the three-axis robot's actions based on the fluctuation range of the clamping force on the workpiece per unit time.

2. The control system for the multi-functional punch press three-axis robot according to claim 1, characterized in that, The clamping determination module responds to the fact that the relative sliding amplitude of the workpiece during the clamping process is less than or equal to the preset sliding amplitude, and determines that the clamping stability of the three-axis robot meets the requirements. The clamping determination module determines that the clamping stability of the three-axis robot does not meet the requirements when the relative sliding amplitude of the workpiece during the clamping process is greater than the preset sliding amplitude.

3. The control system for the multi-functional punch press three-axis robot according to claim 2, characterized in that, In response to the condition that the clamping stability of the three-axis robot does not meet the requirements, the torque compensation module determines whether the vibration resistance stability of the three-axis robot meets the requirements based on the deviation of the workpiece clamping and positioning.

4. The control system for the multi-functional punch press three-axis robot according to claim 3, characterized in that, The torque compensation module responds to the workpiece clamping and positioning deviation being less than or equal to a preset first deviation, thus determining that the vibration resistance stability of the three-axis robot meets the requirements. The torque compensation module responds to the workpiece clamping and positioning deviation being greater than the preset first deviation, and determines that the vibration stability of the three-axis robot does not meet the requirements.

5. The control system for the multi-functional punch press three-axis robot according to claim 4, characterized in that, The torque compensation module responds to the workpiece clamping and positioning deviation being greater than the preset first deviation and less than or equal to the preset second deviation by constructing an adaptive torque compensation mechanism.

6. The control system for the multi-functional punch press three-axis robot according to claim 5, characterized in that, The torque compensation module responds to the workpiece clamping and positioning deviation being greater than the preset second deviation, initially determining that the stability of the clamping friction coefficient does not meet the requirements, and determines whether the stability of the clamping friction coefficient meets the requirements based on the fluctuation range of the clamping force on the workpiece per unit time.

7. The control system for the multi-functional punch press three-axis robot according to claim 6, characterized in that, Constructing an adaptive torque compensation mechanism includes: The torque compensation module is used to construct a dynamic model of the clamping end based on the operating data of the three-axis manipulator of the multi-functional punch press; The clamping end dynamic model is used to calculate the dynamic compensation clamping force based on the clamping end vibration signal collected by the sensor array, and to superimpose the dynamic compensation clamping force and the initial clamping force to output the total output force; The torque compensation module is used to convert the total output force into corresponding drive parameters according to the type of gripper actuator. The torque compensation module is used to output the driving parameters to the corresponding actuator to achieve adaptive control of the clamping force.

8. The control system for the multi-functional three-axis manipulator for punch presses according to claim 7, characterized in that, The trigger offset adjustment module, in response to the condition that the workpiece clamping and positioning deviation is greater than the preset second deviation, determines whether the stability of the clamping friction coefficient meets the requirements based on the fluctuation range of the clamping force on the workpiece per unit time.

9. The control system for the multi-functional three-axis manipulator for punch presses according to claim 8, characterized in that, The trigger offset adjustment module responds to the fluctuation amplitude of the clamping force on the workpiece per unit time being less than or equal to the preset fluctuation amplitude, thus determining that the stability of the clamping friction coefficient meets the requirements. The trigger offset adjustment module responds to the fact that the fluctuation range of the clamping force on the workpiece per unit time is greater than the preset fluctuation range, determines that the stability of the clamping friction coefficient does not meet the requirements, and reduces the trigger offset compensation amount of the three-axis robot's action execution.

10. The control system for the multi-functional punch press three-axis robot according to claim 9, characterized in that, The reduction in the trigger offset compensation amount for the three-axis robot's actions is determined by the difference between the fluctuation range of the clamping force on the workpiece per unit time and the preset fluctuation range.

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