A control method and control system of a high-response servo cylinder

Abstract

This application relates to the field of intelligent key mechanical components technology, specifically to a control method and control system for a high-response servo electric cylinder. The method includes: determining the maximum acceleration correction value; comparing the difference between the maximum acceleration correction value and the maximum acceleration at the current moment to determine the necessity of reconstructing the S-shaped acceleration curve function; obtaining the S-shaped acceleration reconstruction curve function based on Jerk control time, the maximum acceleration correction value, and the maximum speed; analyzing the integral characteristics of the target S-shaped acceleration curve function; and determining the target speed and the latest target position to control the speed and position of the servo electric cylinder. This application addresses the impact of varying workloads and environmental conditions on the accuracy of the servo electric cylinder, as well as the impact of material rigidity differences on the control responsiveness of the servo electric cylinder, thereby improving the adaptability and machining quality of the servo electric cylinder.

Description

Technical Field

[0001] This application relates to the field of intelligent key mechanical components technology, specifically to a control method and control system for a highly responsive servo electric cylinder. Background Technology

[0002] In the field of modern industrial automation, intelligent key mechanical components play a vital role in improving production efficiency and ensuring product quality, with servo electric cylinders being a prime example. A servo electric cylinder is an actuator that converts the rotary motion of a servo motor into linear motion through a transmission mechanism such as a lead screw or synchronous belt. It combines the precise control characteristics of a servo motor with the high efficiency of linear motion and is widely used in numerous industries, including electronic equipment manufacturing, automotive assembly, and aerospace. Compared to traditional hydraulic and pneumatic actuators, servo electric cylinders eliminate the need for complex hydraulic pipelines or air supply systems, offering significant advantages such as cleanliness, energy efficiency, and ease of maintenance.

[0003] In practical applications, traditional control algorithms struggle to adapt to complex and variable workloads and environmental conditions. For example, during start-up and shutdown, traditional trapezoidal acceleration / deceleration curves can cause abrupt acceleration changes, generating significant mechanical shocks and vibrations. These shocks reduce the positioning accuracy of the servo cylinder, thus decreasing the system's response speed and stability. Furthermore, during workpiece machining, the workpiece material's rigidity varies, resulting in different responses to applied forces and displacements. Materials with high rigidity deform less under stress, requiring larger forces to produce a certain displacement; conversely, materials with low rigidity deform easily under stress, producing larger displacements with smaller forces. Existing technologies for servo cylinder acceleration / deceleration control fail to consider the impact of varying workloads and environmental conditions on servo cylinder accuracy, as well as the influence of material rigidity differences on servo cylinder control responsiveness, thereby reducing the adaptability and machining quality of the servo cylinder. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this application is to provide a control method and control system for a highly responsive servo electric cylinder. The specific technical solution adopted is as follows:

[0005] In a first aspect, embodiments of this application provide a control method for a highly responsive servo electric cylinder, the method comprising the following steps:

[0006] The system acquires the current target position, maximum speed, and maximum acceleration of the servo cylinder during its operation, and also acquires the actual position and acceleration of the servo cylinder in real time.

[0007] Based on the current maximum speed and maximum acceleration of the servo cylinder, the S-curve function of the servo cylinder with time as the independent variable and acceleration as the dependent variable is determined; by analyzing the difference between the actual position and the target position of the servo cylinder at each moment, and combining the load inertia and S-curve function value of the servo cylinder at each moment, the correction acceleration of the servo cylinder at each moment is determined.

[0008] The rigidity of the workpiece is obtained at the moment when the stamping process ends after the most recent contact between the servo cylinder and the workpiece. Combined with the preset initial Jerk control time, the Jerk control time at each moment is determined. The difference between the rigidity of the workpiece and the preset reference rigidity value is compared. Combined with the correction acceleration and the maximum acceleration, the maximum acceleration correction value at each moment is determined.

[0009] By comparing the difference between the maximum acceleration correction value and the maximum acceleration at the current moment, the necessity of reconstructing the S-shaped acceleration curve function is determined. Based on the Jerk control time, maximum acceleration correction value, and maximum speed at the current moment, the reconstructed S-shaped acceleration curve function is obtained and recorded together with the unreconstructed S-shaped acceleration curve function as the target S-shaped acceleration curve function. The integral characteristics of the target S-shaped acceleration curve function are analyzed to determine the target speed and latest target position of the servo cylinder at the current moment, so as to control the speed and position of the servo cylinder at the current moment.

[0010] Preferably, determining the S-curve function of the servo electric cylinder with time as the independent variable and acceleration as the dependent variable includes:

[0011] S-curve acceleration function of servo electric cylinder The expression is:

[0012] In the formula, Indicates the initial maximum acceleration; ,in, Indicates maximum speed; This indicates the preset initial Jerk control time.

[0013] Preferably, the method for determining the correction acceleration of the servo electric cylinder at each time point is as follows:

[0014] A coordinate system is constructed with the target position as the origin, the horizontal position of the servo cylinder as the horizontal axis and the direction of movement of the servo cylinder as the positive direction, and the vertical direction passing through the origin and perpendicular to the horizontal position of the servo cylinder as the vertical axis.

[0015] Correction acceleration of the servo electric cylinder at time t The expression is: In the formula, The S-curve acceleration function value of the servo electric cylinder at time t is represented. This represents the normalized value of the load inertia of the servo electric cylinder at time t. This represents the difference between the x-coordinate of the target position and the x-coordinate of the actual position of the servo cylinder at time t. This represents the distance between the actual position of the servo cylinder and the target position at time t.

[0016] Preferably, the expression for the Jerk control time at each time point is: In the formula, This represents the Jerk control time at time t; This indicates the preset initial Jerk control time; This indicates the rigidity of the workpiece at the moment the stamping process ended after the most recent contact between the servo electric cylinder and the workpiece before time t. Indicates the preset reference stiffness value; This indicates the preset adjustment coefficient.

[0017] Preferably, the expression for the maximum acceleration correction value at each time point is: In the formula, This represents the maximum acceleration correction value at time t; Indicates the maximum acceleration; Indicates the preset reference stiffness value; This indicates the rigidity of the workpiece at the moment the stamping process ended after the most recent contact between the servo electric cylinder and the workpiece before time t. represents the preset rigidity sensitivity index; max[] represents the maximum value function.

[0018] Preferably, the determination of the necessity for reconstructing the S-shaped acceleration curve function includes:

[0019] If the maximum acceleration correction value at the current moment is greater than the maximum acceleration, then the S-curve function is reconstructed; otherwise, the S-curve function is not reconstructed.

[0020] Preferably, the method for obtaining the S-shaped acceleration reconstruction curve function is as follows:

[0021] S-shaped acceleration reconstruction curve function at the current moment The expression is:

[0022] In the formula, Indicates the maximum acceleration; ,in, Indicates maximum speed; This indicates the Jerk control time at the current moment.

[0023] Preferably, the method for determining the target speed and latest target position of the servo electric cylinder at the current moment is as follows:

[0024] Calculate the integral and double integral of the target S-curve acceleration curve function at the current moment, and use them as the target velocity and latest target position of the servo electric cylinder at the current moment, respectively.

[0025] Preferably, controlling the speed and position of the servo cylinder at the current moment includes:

[0026] The target speed and latest target position of the servo cylinder at the current moment are converted into analog voltage signals and pulse counts by the driver, respectively. The speed of the servo cylinder is controlled by the analog voltage signals, and the position of the servo cylinder is controlled by the pulse counts.

[0027] Secondly, embodiments of this application also provide a control system for a high-response servo electric cylinder, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of the control method for a high-response servo electric cylinder described in any one of the above-mentioned embodiments.

[0028] This application has at least the following beneficial effects:

[0029] This application achieves smooth acceleration and deceleration by constructing an S-shaped acceleration curve function and dynamically corrects the acceleration based on position error and load inertia. Compared with traditional solutions, this solution introduces load inertia to suppress tracking deviation in real time. This effectively avoids overshoot shocks caused by high-inertia loads with large position errors due to corrections based solely on position errors, effectively balancing control accuracy and stability under different load scenarios and improving the responsiveness and machining accuracy of the servo cylinder. Furthermore, this application achieves adaptive control of the servo cylinder by dynamically adjusting the Jerk control time and acceleration upper limit by acquiring workpiece rigidity in real time and combining preset parameters, effectively solving the problems of traditional control methods. This invention addresses the issue of the inability of the current method to adapt to differences in workpiece rigidity, achieving efficient and precise machining of workpieces made of different materials. It avoids system oscillations and workpiece damage caused by rigidity mismatch, improving the adaptability and machining quality of the servo electric cylinder. Furthermore, this application utilizes position error and load inertia to dynamically adjust acceleration, and combines this with adaptive adjustment of Jerk control time and acceleration upper limit based on workpiece rigidity. This effectively suppresses system oscillations, avoiding mechanical impacts and workpiece damage caused by rigidity mismatch. By real-time judgment of the necessity for reconstructing the S-shaped acceleration curve, it ensures efficient and precise machining of workpieces made of different materials by the servo electric cylinder, significantly improving its adaptability and machining quality. Attached Figure Description

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

[0031] Figure 1 A flowchart illustrating the steps of a control method for a high-response servo electric cylinder provided in one embodiment of this application;

[0032] Figure 2 This is a schematic diagram illustrating the maximum acceleration correction value extraction process provided in one embodiment of this application. Detailed Implementation

[0033] To further illustrate the technical means and effects adopted by this application to achieve the intended inventive purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a control method and control system for a high-response servo electric cylinder proposed in this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0035] The following description, in conjunction with the accompanying drawings, details the specific scheme of the control method and control system for a high-response servo electric cylinder provided in this application.

[0036] Please see Figure 1 The diagram illustrates a flowchart of a control method for a high-response servo electric cylinder according to an embodiment of this application. The method includes the following steps:

[0037] Step S1: Obtain the current target position, maximum speed and maximum acceleration of the servo electric cylinder during operation, and obtain the actual position and acceleration of the servo electric cylinder in real time.

[0038] The upper-level control system typically consists of a programmable logic controller (PLC), an industrial computer (PC), and motion controllers, such as a CNC system. Its core function is to generate macroscopic control commands, such as target position, speed, and machining parameters, based on the production process, technological requirements, or user input, and then send them down to the lower-level execution system.

[0039] The control commands include: target position, specifying the final position that the servo cylinder needs to move to; maximum speed, specifying the maximum speed that the servo cylinder is allowed to reach during movement; maximum acceleration, specifying the maximum acceleration that the servo cylinder is allowed to achieve during startup and acceleration; and data source determination flag, used to indicate the input type of the command, such as SPI pulse input or analog output.

[0040] The specific steps for parsing commands from the host control system are as follows:

[0041] The system receives command signals from the host control system through appropriate interfaces, such as SPI pulse ports or analog ports. These signals may be in the form of digital pulses, voltages, or currents.

[0042] Based on the data source determination mark, the input type of the instruction is identified. If it is an SPI pulse input, the pulse signal is processed and analyzed. If it is an analog input, an analog-to-digital converter is used to convert the analog signal into a digital signal, and then it is processed.

[0043] For analog input commands, the digital signal after conversion by analog-to-digital converter is normalized to ensure data accuracy and consistency.

[0044] The current target position, maximum speed, and maximum acceleration of the servo cylinder during operation are extracted from the processed command signal. Furthermore, the actual position and acceleration of the servo cylinder are acquired in real time. The acquisition frequency of the actual position and acceleration is set to f. The value of the data acquisition frequency f is set manually. In this embodiment, the value of the data acquisition frequency f is 1MHz. In actual applications, as other implementation methods, the implementer can also set it according to the specific situation. This embodiment does not impose any special restrictions.

[0045] The process of obtaining the target position, maximum speed, and maximum acceleration using a host control system is a well-known technology, and its specific acquisition principle will not be elaborated here.

[0046] Step S2: Based on the current maximum speed and maximum acceleration of the servo cylinder, determine the S-curve function of the servo cylinder with time as the independent variable and acceleration as the dependent variable; by analyzing the difference between the actual position and the target position of the servo cylinder at each moment, and combining the load inertia and S-curve function value of the servo cylinder at each moment, determine the correction acceleration of the servo cylinder at each moment.

[0047] Traditional S-shaped acceleration / deceleration curves typically consist of seven stages: acceleration, uniform acceleration, deceleration, constant speed, acceleration / deceleration, uniform deceleration, and deceleration / deceleration. In this embodiment, taking the acceleration stage (acceleration, uniform acceleration, and deceleration) during workpiece machining by a servo cylinder as an example, based on the current maximum speed and maximum acceleration of the servo cylinder, an S-shaped acceleration curve function for the servo cylinder is determined, with time as the independent variable and acceleration as the dependent variable. This ensures that the servo cylinder contacts the workpiece at a specific speed to complete the stamping process. The specific expression of the S-shaped acceleration / deceleration curve function is as follows:

[0048] S-curve acceleration function of servo electric cylinder The expression is:

[0049] In the formula, Indicates the initial maximum acceleration; ,in, Indicates maximum speed; This indicates the preset initial Jerk control time.

[0050] Here, Jerk refers to the rate of change of acceleration, i.e. jerk. The acceleration of a traditional trapezoidal curve is a rectangular wave during the start-up and deceleration phases, with two abrupt acceleration points. By designing the acceleration change as a piecewise linear or polynomial function, Jerk is ensured to remain constant during the acceleration and deceleration phases, eliminating abrupt changes.

[0051] It should be noted that the preset initial Jerk control time is set manually. The preset initial Jerk control time is generally in the range of 10~30ms. In this embodiment, the preset initial Jerk control time is set to 20ms. In actual application, as other implementation methods, implementers can also set it according to specific circumstances. This embodiment does not impose any special restrictions.

[0052] Furthermore, in traditional servo electric cylinder control, due to factors such as slow controller processing speed, changes in load inertia, or mechanical backlash, the actual movement tends to lag behind the planned trajectory, leading to the accumulation of position errors. If not corrected in time, the electric cylinder may accelerate or decelerate rapidly at the end to catch up with the target, causing mechanical shock or overshoot. The core of dynamic acceleration correction is to suppress tracking deviation in real time, avoid secondary impacts caused by error accumulation, and ensure precise synchronization between the electric cylinder movement and the planned curve.

[0053] Therefore, this embodiment analyzes the difference between the actual position and the target position of the servo cylinder at each moment, and combines the load inertia and S-curve acceleration function value of the servo cylinder at each moment to determine the correction acceleration of the servo cylinder at each moment, specifically:

[0054] As one implementation method, in this embodiment, a coordinate system is constructed with the target position as the origin, the horizontal position of the servo cylinder as the horizontal axis and the direction of movement of the servo cylinder as the positive direction, and the vertical direction passing through the origin and perpendicular to the horizontal position of the servo cylinder as the vertical axis.

[0055] Furthermore, by comparing the difference between the actual position and the target position of the servo cylinder, the acceleration of the servo cylinder at each moment has been corrected. Specifically:

[0056] In this embodiment, the correction acceleration of the servo electric cylinder at time t The expression is: In the formula, The S-curve acceleration function value of the servo electric cylinder at time t is represented. This represents the normalized value of the load inertia of the servo electric cylinder at time t. This represents the difference between the x-coordinate of the target position and the x-coordinate of the actual position of the servo cylinder at time t. This represents the distance between the actual position of the servo cylinder and the target position at time t.

[0057] Among them, load inertia is a well-known technology. Load inertia refers to the inertial physical quantity of the load driven by the servo electric cylinder resisting the change of speed during the movement process. It reflects the load's ability to maintain the current motion state. The larger the load inertia, the slower the system response, and the smaller the adjustment amount is required to avoid over-adjustment. The smaller the load inertia, the more sensitive the system is, and the adjustment amount can be appropriately increased to quickly eliminate errors. In this embodiment, the load inertia is implemented by FPGA. The specific process and principle of using FPGA to obtain load inertia in real time will not be described in detail.

[0058] Based on the correction acceleration of the servo cylinder at each time point, it can be understood that if the difference between the horizontal coordinate of the actual position of the servo cylinder and the horizontal coordinate of the target position at time t is greater than 0, it means that the actual position of the servo cylinder at time t is lagging behind the target position, and the acceleration can be increased to catch up with the target. At the same time, if the load inertia is smaller, it means that the system response is more sensitive, and the acceleration adjustment amount can be appropriately increased to quickly eliminate the error.

[0059] Conversely, if the difference between the x-coordinate of the actual position of the servo cylinder and the x-coordinate of the target position at time t is less than 0, it means that the actual position of the servo cylinder at time t is ahead of the target position. The acceleration can be reduced to suppress oscillation. At the same time, if the load inertia is larger, it means that the system response is slower. The acceleration adjustment can be appropriately reduced to avoid excessive acceleration adjustment leading to system instability or aggravated oscillation.

[0060] Thus, this embodiment achieves smooth acceleration and deceleration by constructing an S-shaped acceleration curve function, and dynamically corrects the acceleration based on position error and load inertia, thereby suppressing tracking deviation in real time and avoiding secondary impacts caused by error accumulation. This method effectively balances control accuracy and stability under different load scenarios, and improves the responsiveness and machining accuracy of the servo electric cylinder.

[0061] Step S3: Obtain the workpiece rigidity at the moment when the stamping process ends after the most recent contact between the servo cylinder and the workpiece, and combine it with the preset initial Jerk control time to determine the Jerk control time at each moment; compare the difference between the workpiece rigidity and the preset reference rigidity value, and combine it with the correction acceleration and the maximum acceleration to determine the maximum acceleration correction value at each moment.

[0062] The aforementioned acceleration correction based on position error is a fine-tuning of the original acceleration curve to avoid tracking errors in acceleration. However, this adjustment does not take into account the differences in the mechanical properties of the workpiece itself. High-rigidity materials are sensitive to changes in acceleration and are prone to oscillations caused by sudden force changes; low-rigidity materials, on the other hand, allow for higher acceleration to improve efficiency. After a batch of workpieces is processed, the rigidity of the new workpieces may change significantly, and the original acceleration curve may no longer be applicable, so reconstruction is required.

[0063] When a servo electric cylinder contacts a workpiece, the rigidity of the material directly affects the system's dynamic response. Materials with high rigidity, such as metals, exhibit small displacement changes under stress. However, if the acceleration changes too rapidly, it can easily generate instantaneous impact forces, leading to mechanical vibration or workpiece damage. Materials with low rigidity, such as plastics, exhibit large displacement changes, allowing for faster acceleration changes to improve efficiency. Traditional acceleration / deceleration control does not consider changes in workpiece rigidity and cannot adapt to these differences in real time. Therefore, adaptive adjustment is necessary through rigidity calculation.

[0064] In this embodiment, the rigidity of the workpiece at the end of the stamping process after the most recent contact between the servo cylinder and the workpiece is obtained, and combined with the preset initial Jerk control time, the Jerk control time at each moment is determined; the difference between the rigidity of the workpiece and the preset reference rigidity value is compared, and combined with the corrected acceleration and the maximum acceleration, the maximum acceleration correction value at each moment is determined, specifically:

[0065] First, the rigidity of the workpiece at the end of the stamping process after the most recent contact between the servo cylinder and the workpiece is obtained. Specifically, a force sensor is used to acquire the force at the end and beginning of the stamping process after the most recent contact between the servo cylinder and the workpiece. A displacement sensor is used to acquire the displacement between the end and beginning of the stamping process after the most recent contact between the servo cylinder and the workpiece. The change in force between the end and beginning times is calculated, and the ratio of the change in force to the displacement is taken as the rigidity of the workpiece at the end of the stamping process after the most recent contact between the servo cylinder and the workpiece. The larger the rigidity value, the stronger the material's resistance to deformation, and the higher the system's sensitivity to changes in acceleration; that is, the same change in acceleration will lead to greater force fluctuations. It should be noted that the change in workpiece material rigidity is calculated every time the servo cylinder contacts the workpiece during each stamping operation.

[0066] The rigid acquisition method is a well-known technology, and will only be briefly described in this embodiment. The specific acquisition process will not be described in detail.

[0067] Furthermore, this embodiment determines the Jerk control time at each moment based on the workpiece rigidity at the end of the stamping process after the most recent contact between the servo cylinder and the workpiece, combined with a preset initial Jerk control time. Specifically:

[0068] As one implementation method, in this embodiment, the Jerk control time at time t is... The expression is: In the formula, This indicates the preset initial Jerk control time; This indicates the rigidity of the workpiece at the moment the stamping process ended after the most recent contact between the servo electric cylinder and the workpiece before time t. Indicates the preset reference stiffness value; This indicates the preset adjustment coefficient.

[0069] It should be noted that the preset reference stiffness value and the preset adjustment coefficient are set manually. The range of the preset reference stiffness value is generally 100~1000N / mm. In this embodiment, the preset reference stiffness value is set to 500N / mm and the preset adjustment coefficient is set to 0.6. In actual application, as other implementation methods, implementers can also set them according to specific circumstances. This embodiment does not impose any special restrictions.

[0070] Based on the Jerk control time at each moment, it can be understood that when the workpiece has high rigidity, i.e. When the force is large, in order to suppress force fluctuations, the Jerk control time needs to be increased, that is, the Jerk value needs to be decreased to make the acceleration change more gradual; conversely, when the workpiece rigidity is weak, that is... When the value is small, the Jerk control time can be reduced, i.e., the Jerk value can be increased to speed up the motion response.

[0071] Furthermore, by combining the real-time rigid scaling acceleration upper limit, the material compatibility problem is further addressed. This avoids system oscillations caused by excessive acceleration in high-rigidity materials while releasing the rapid motion potential of low-rigidity materials. Therefore, this embodiment determines the maximum acceleration correction value at each moment by comparing the difference between the workpiece's rigidity and the preset reference rigidity value, and by combining the corrected acceleration and the maximum acceleration. Specifically:

[0072] Maximum acceleration correction value at time t The expression is: In the formula, Indicates the maximum acceleration; Indicates the preset reference stiffness value; This indicates the rigidity of the workpiece at the moment the stamping process ended after the most recent contact between the servo electric cylinder and the workpiece before time t. represents the preset rigidity sensitivity index; max[] represents the maximum value function.

[0073] It should be noted that the preset rigidity sensitivity index is set manually. In this embodiment, the preset rigidity sensitivity index is 0.8. In actual applications, as other implementation methods, implementers can also set it according to specific circumstances. This embodiment does not impose any special restrictions.

[0074] Preferably, the schematic diagram of the maximum acceleration correction value extraction process provided in this embodiment is as follows: Figure 2 As shown.

[0075] Based on the maximum acceleration correction values ​​at each moment, it can be understood that when the workpiece has high rigidity, i.e. When the workpiece is relatively stiff, the upper limit of acceleration needs to be lowered to suppress force fluctuations and mechanical impacts; conversely, when the workpiece rigidity is weak, i.e. If the acceleration is relatively small, the upper limit of acceleration can be appropriately increased to speed up motion response and improve efficiency.

[0076] Thus, this embodiment achieves adaptive control of the servo electric cylinder by acquiring the workpiece rigidity in real time and dynamically adjusting the Jerk control time and acceleration upper limit in combination with preset parameters. This method effectively solves the problem that traditional control methods cannot adapt to differences in workpiece rigidity, realizes efficient and precise processing of workpieces of different materials, avoids system oscillation and workpiece damage caused by rigidity mismatch, and improves the adaptability and processing quality of the servo electric cylinder.

[0077] Step S4: By comparing the difference between the maximum acceleration correction value and the maximum acceleration at the current moment, determine the necessity of reconstructing the S-shaped acceleration curve function. Based on the Jerk control time, maximum acceleration correction value, and maximum speed at the current moment, obtain the reconstructed S-shaped acceleration curve function, and record it together with the unreconstructed S-shaped acceleration curve function as the target S-shaped acceleration curve function. Analyze the integral characteristics of the target S-shaped acceleration curve function to determine the target speed and latest target position of the servo cylinder at the current moment, so as to control the speed and position of the servo cylinder at the current moment.

[0078] Based on the above analysis, this embodiment performs real-time acceleration correction based on position error. However, when switching workpieces, their rigidity may change significantly, and the original basic S-curve acceleration curve may no longer be applicable, requiring reconstruction of the S-curve acceleration curve. Therefore, this embodiment determines the necessity of S-curve acceleration curve function reconstruction by comparing the difference between the maximum acceleration correction value and the maximum acceleration at the current moment. Based on the Jerk control time, maximum acceleration correction value, and maximum speed at the current moment, the reconstructed S-curve acceleration curve function is obtained and recorded as the target S-curve acceleration curve function along with the unreconstructed S-curve acceleration curve function. The integral characteristics of the target S-curve acceleration curve function are analyzed to determine the target speed and latest target position of the servo cylinder at the current moment, so as to control the speed and position of the servo cylinder at the current moment. Specifically:

[0079] In this embodiment, if the maximum acceleration correction value at the current moment is greater than the maximum acceleration, the S-curve function is reconstructed; otherwise, the S-curve function is not reconstructed.

[0080] Furthermore, this embodiment obtains the S-shaped acceleration reconstruction curve function based on the Jerk control time, maximum acceleration correction value, and maximum velocity at the current moment, specifically:

[0081] S-shaped acceleration reconstruction curve function at the current moment The expression is:

[0082] In the formula, Indicates the maximum acceleration; ,in, Indicates maximum speed; This indicates the Jerk control time at the current moment.

[0083] Furthermore, in this embodiment, the integral and double integral of the target S-curve acceleration curve function at the current moment are calculated and used as the target velocity and latest target position of the servo electric cylinder at the current moment, respectively.

[0084] The calculation of integrals and double integrals are well-known techniques, and their specific calculation processes will not be elaborated here.

[0085] Furthermore, the target speed and latest target position of the servo cylinder at the current moment are converted into analog voltage signals and pulse counts by the driver, respectively. The analog voltage signals are used to control the speed of the motor, thereby controlling the speed of the servo cylinder, and the pulse counts are used to control the position of the servo cylinder.

[0086] The process of converting the target speed and the latest target position into analog voltage signals and pulse counts are well-known technologies, and their specific conversion processes will not be elaborated here. In addition, the processes of controlling the motor speed using analog voltage signals and controlling the position of the servo cylinder using pulse counts are also well-known technologies, and their specific processes and principles will not be elaborated here.

[0087] Thus, this embodiment achieves high-precision control of the servo cylinder's motion by acquiring the target position, velocity, acceleration, and workpiece rigidity in real time, constructing and dynamically correcting the S-shaped acceleration curve. This method dynamically adjusts the acceleration using position error and load inertia, and adaptively adjusts the Jerk control time and acceleration upper limit based on workpiece rigidity, effectively suppressing system oscillations and avoiding mechanical impacts and workpiece damage caused by rigidity mismatch. By judging the necessity of reconstructing the S-shaped acceleration curve in real time, it ensures the efficient and precise processing of workpieces of different materials by the servo cylinder, significantly improving the adaptability and processing quality of the servo cylinder.

[0088] Based on the same inventive concept as the above methods, this application also provides a control system for a high-response servo electric cylinder, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above-described control methods for a high-response servo electric cylinder.

[0089] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0090] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0091] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A control method of a high-response servo cylinder, characterized by, The method includes the following steps: The system acquires the current target position, maximum speed, and maximum acceleration of the servo cylinder during its operation, and also acquires the actual position and acceleration of the servo cylinder in real time. Based on the current maximum speed and maximum acceleration of the servo cylinder, the S-curve function of the servo cylinder with time as the independent variable and acceleration as the dependent variable is determined; by analyzing the difference between the actual position and the target position of the servo cylinder at each moment, and combining the load inertia and S-curve function value of the servo cylinder at each moment, the correction acceleration of the servo cylinder at each moment is determined. The rigidity of the workpiece is obtained at the moment when the stamping process ends after the most recent contact between the servo electric cylinder and the workpiece. Combined with the preset initial Jerk control time, the Jerk control time at each moment is determined. The difference between the rigidity of the workpiece and the preset reference rigidity value is compared. Combined with the correction acceleration and the maximum acceleration, the maximum acceleration correction value at each moment is determined. By comparing the difference between the maximum acceleration correction value and the maximum acceleration at the current moment, the necessity of reconstructing the S-shaped acceleration curve function is determined. Based on the Jerk control time, maximum acceleration correction value, and maximum speed at the current moment, the reconstructed S-shaped acceleration curve function is obtained and recorded together with the unreconstructed S-shaped acceleration curve function as the target S-shaped acceleration curve function. The integral characteristics of the target S-shaped acceleration curve function are analyzed to determine the target speed and latest target position of the servo cylinder at the current moment, so as to control the speed and position of the servo cylinder at the current moment.

2. The control method for a high-response servo electric cylinder as described in claim 1, characterized in that, The determination of the S-curve acceleration curve function of the servo electric cylinder with time as the independent variable and acceleration as the dependent variable includes: S-curve acceleration function of servo electric cylinder The expression is: In the formula, Indicates the initial maximum acceleration; ,in, Indicates maximum speed; This indicates the preset initial Jerk control time.

3. The control method for a high-response servo electric cylinder as described in claim 1, characterized in that, The method for determining the correction acceleration of the servo electric cylinder at each time point is as follows: A coordinate system is constructed with the target position as the origin, the horizontal position of the servo cylinder as the horizontal axis and the direction of movement of the servo cylinder as the positive direction, and the vertical direction passing through the origin and perpendicular to the horizontal position of the servo cylinder as the vertical axis. Correction acceleration of the servo electric cylinder at time t The expression is: In the formula, The S-curve acceleration function value of the servo electric cylinder at time t is represented. This represents the normalized value of the load inertia of the servo electric cylinder at time t. This represents the difference between the x-coordinate of the target position and the x-coordinate of the actual position of the servo cylinder at time t. This represents the distance between the actual position of the servo cylinder and the target position at time t.

4. The control method for a high-response servo electric cylinder as described in claim 1, characterized in that, The expressions for the Jerk control time at each time point are as follows: In the formula, This represents the Jerk control time at time t; This indicates the preset initial Jerk control time; This indicates the rigidity of the workpiece at the moment the stamping process ended after the most recent contact between the servo electric cylinder and the workpiece before time t. Indicates the preset reference stiffness value; This indicates the preset adjustment coefficient.

5. The control method for a high-response servo electric cylinder as described in claim 3, characterized in that, The expression for the maximum acceleration correction value at each time point is: In the formula, This represents the maximum acceleration correction value at time t; Indicates the maximum acceleration; Indicates the preset reference stiffness value; This indicates the rigidity of the workpiece at the moment the stamping process ended after the most recent contact between the servo electric cylinder and the workpiece before time t. represents the preset rigidity sensitivity index; max[] represents the maximum value function.

6. The control method for a high-response servo electric cylinder as described in claim 1, characterized in that, The necessity of determining the reconstruction of the S-shaped acceleration curve function includes: If the maximum acceleration correction value at the current moment is greater than the maximum acceleration, then the S-curve function is reconstructed; otherwise, the S-curve function is not reconstructed.

7. The control method for a high-response servo electric cylinder as described in claim 4, characterized in that, The method for obtaining the S-shaped acceleration reconstruction curve function is as follows: S-shaped acceleration reconstruction curve function at the current moment The expression is: In the formula, Indicates the maximum acceleration; ,in, Indicates maximum speed; This indicates the Jerk control time at the current moment.

8. The control method for a high-response servo electric cylinder as described in claim 1, characterized in that, The method for determining the target speed and latest target position of the servo electric cylinder at the current moment is as follows: Calculate the integral and double integral of the target S-curve acceleration curve function at the current moment, and use them as the target velocity and latest target position of the servo electric cylinder at the current moment, respectively.

9. The control method for a high-response servo electric cylinder as described in claim 1, characterized in that, The control of the speed and position in the servo electric cylinder at the current moment includes: The target speed and latest target position of the servo cylinder at the current moment are converted into analog voltage signals and pulse counts by the driver, respectively. The speed of the servo cylinder is controlled by the analog voltage signals, and the position of the servo cylinder is controlled by the pulse counts.

10. A control system for a high-response servo electric cylinder, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the control method for a high-response servo electric cylinder as described in any one of claims 1-9.

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