A full closed loop force / position hybrid control system for a servo pressure control system

Abstract

The application discloses a full-closed loop force / position hybrid control system of a servo pressure control system, relates to the technical field of force / position hybrid control, and aims to solve the technical problem of blind and inaccurate compaction process control of a current servo press due to the incapability of sensing the real-time deformation stage of materials, and comprises a signal acquisition and processing module, a core control decision module, a driving and executing module, and a man-machine interaction and parameter management module. The adaptive compaction control unit in the core control decision module and the pressure decay analysis subunit thereof are designed, so that the real-time deformation stage of the electrode plate material in the compaction process can be sensed and accurately judged online. The effect makes the control system be able to sense the microstructure evolution of the material in real time like having a sense of touch, instead of blind operation, and solves the problem of blind and inaccurate compaction process control of the current servo press due to the incapability of sensing the real-time deformation stage of the material.

Description

Technical Field

[0001] This invention relates to the field of force / position hybrid control technology, and more specifically, to a fully closed-loop force / position hybrid control system for a servo pressure control system. Background Technology

[0002] The fully closed-loop force-position hybrid control of the servo pressure control system is an advanced control technology in the field of precision pressure machining. Its core lies in the fact that the system is equipped with both high-precision pressure and displacement sensors, forming two parallel real-time detection closed loops for "force" and "position." Based on the feedback signals from these two closed loops, the controller dynamically coordinates and outputs commands to drive actuators (such as pressure rollers and punches), thereby achieving synchronous and precise control of the two key physical quantities—pressure and displacement (or thickness)—during workpiece machining.

[0003] In the rolling compaction process of lithium-ion battery electrode sheets, achieving both extremely high compaction density and an ideal pore connectivity structure is a crucial dual requirement for improving the battery's volumetric energy density and rate performance. However, there is an inherent contradiction between these two aspects in the process: pursuing "high density" requires applying sufficient compaction energy, which can easily crush the micropores that are essential for ion transport; conversely, adopting a conservative compaction strategy to "preserve porosity" makes it difficult to achieve the designed energy density target.

[0004] Existing servo press control strategies, whether single pressure closed-loop control or position closed-loop control, cannot resolve this contradiction due to their limited sensing dimensions. Force control ensures pressure stability but cannot detect and compensate for local density differences caused by uneven slurry coating, sacrificing thickness uniformity. Position control can precisely control the overall thickness but is insensitive to local material hardness differences, posing a risk of local overpressure damage or underpressure, and failing to guarantee density uniformity. Moreover, the electrode material dynamically undergoes different micro-deformation stages during compaction, including plastic compaction, viscoelastic relaxation, and elastic recovery, each with drastically different pressure and displacement input requirements. Existing fixed-program-based control or simple force / position mode switching essentially operates blindly without knowing the real-time deformation stage of the material, unable to identify the current stage, and therefore unable to apply the most appropriate control action at the optimal time. Therefore, we propose a fully closed-loop force / position hybrid control system for servo pressure control. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art, adapt to practical needs, and provide a fully closed-loop force / position hybrid control system for servo pressure control, so as to solve the technical problem that the current servo press cannot sense the real-time deformation stage of the material, resulting in blind and inaccurate control of the compaction process.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a fully closed-loop force / position hybrid control system for servo pressure control system, comprising a signal acquisition and processing module, a core control decision module, a drive and execution module, and a human-machine interaction and parameter management module; The drive and execution module includes a servo power mechanism and a pressure execution mechanism driven by the servo power mechanism; The signal acquisition and processing module is used to acquire pressure feedback signals and position feedback signals from the pressure actuator in real time. The core control decision module is used to receive the processed feedback signal and output control commands based on the hybrid closed-loop control logic of force and position. This module includes an adaptive compaction control unit, which, during the process of the pressure actuator compacting the workpiece, controls the pressure actuator to enter a position lock state and monitor the pressure decay characteristics after an initial compaction target is reached. Then, based on the different characteristic ranges of the pressure decay characteristics, it makes adaptive decisions and triggers corresponding fine-tuning control actions. The drive and execution module is used to receive control commands and drive the servo power mechanism to control the pressure actuator to perform corresponding actions, including preliminary densification action, position locking action, micro-amplitude additional compaction action, pressure holding optimization action, and elastic recovery allowance action. The human-computer interaction and parameter management module is used for setting, storing, recalling process parameters and displaying process information.

[0007] Preferably, the signal acquisition and processing module includes a high-precision pressure sensing unit, a high-resolution position sensing unit, and a signal conditioning and calculation unit; The high-precision pressure sensing unit is installed in the force flow path of the pressure actuator to detect the actual pressure value applied to the workpiece in real time. The high-resolution position sensing unit is used to detect the position value in real time, which reflects the degree of action of the pressure actuator on the workpiece. The signal conditioning and calculation unit is used to filter, amplify and digitize the original sensing signal, and calculate the real-time pressure decay rate through the pressure decay rate algorithm.

[0008] Preferably, the pressure decay rate algorithm formula is as follows: ; in, for Real-time pressure decay rate at any given moment for Real-time pressure value at any moment ， for Real-time pressure value at any given moment. This is the preset monitoring time window.

[0009] Preferably, the adaptive compaction control unit in the core control decision module includes a pressure decay analysis subunit, a decision logic subunit, and a cyclic judgment subunit; The pressure decay analysis subunit is used to calculate the pressure decay characteristics based on the signal provided by the signal acquisition and processing module when the position is locked. The decision logic subunit is used to compare the pressure attenuation characteristics with a preset threshold range, and generate corresponding control commands accordingly. The loop judgment subunit is used to determine whether the workpiece state has reached the final process target after executing the control command by using the compaction target achievement judgment algorithm, and to control whether the process returns to the pressure decay analysis subunit for the next loop.

[0010] Preferably, the decision logic subunit is configured as follows: When the pressure decay rate is less than or equal to the first threshold, the decision triggers a micro-amplitude additional compaction command. When the pressure decay rate is greater than the first threshold and less than the second threshold, the decision triggers a pressure holding optimization command. When the pressure decay rate is greater than or equal to the second threshold or the pressure decay tends to stabilize, the decision triggers the elastic recovery permission command.

[0011] Preferably, the compaction target achievement judgment algorithm includes a thickness target judgment algorithm and a density target judgment algorithm; The formula for the thickness target determination algorithm is as follows: ; in, for Real-time thickness of the electrode sheet The final target thickness of the electrode sheet, For thickness tolerance; The formula for the density target judgment algorithm is as follows: ; in, for Real-time compaction density of the electrode sheet The final target compaction density of the electrode sheet, This represents the allowable density deviation.

[0012] Preferably, the drive and execution module further includes a multi-mode drive control unit; The servo power mechanism is used to provide controllable, highly responsive linear or rotary power output; The pressure actuator is mechanically connected to the servo power mechanism to convert power into a precise pressing action on the workpiece; The multi-mode drive control unit is electrically connected to the core control decision module and the servo power mechanism, respectively. It is used to receive control commands and, based on the force-position hybrid control drive algorithm, seamlessly switch and drive between force closed-loop control mode, position closed-loop control mode and position locking mode to ensure the precise execution of each control action. The formula for the force-position hybrid control drive algorithm is as follows: ; ; ; in, The output drive signal of the multi-mode drive control unit For thickness deviation, for Set the thickness at all times. for Real-time thickness This represents the rate of change of thickness deviation. For pressure deviation, for Set pressure at all times. for Real-time pressure This is the proportional coefficient for position closed-loop control. For the differential coefficients of the position closed-loop control, For the position closed-loop control, is the integral coefficient. The proportional coefficient for closed-loop force control.

[0013] Preferably, the multi-mode drive control unit is configured as follows: When performing a micro-amplitude additional compaction action, the position lock state is released and the position control mode is switched, driving the pressure actuator to increase the degree of action by a preset micro-displacement, and then re-entering the position lock state; When performing pressure holding optimization, maintain the position locked state and maintain the preset optimization holding time; When performing the elastic recovery allowable action, switch to force control mode, reduce the current pressure value by a preset percentage, and maintain the preset release time.

[0014] Preferably, the human-computer interaction and parameter management module includes a process parameter setting and storage unit and a real-time status display unit; The process parameter setting and storage unit is used to set and store the initial target, the final target, the pressure decay characteristic criterion threshold, and the relevant parameters of each control action; The real-time status display unit is used to dynamically display real-time pressure curves, real-time position curves, pressure decay rate, current control stage, and cycle count information.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves online sensing and accurate judgment of the real-time deformation stage of the electrode sheet material during the compaction process by designing an adaptive compaction control unit and its pressure decay analysis subunit in the core control decision module. This effect enables the control system to perceive the evolution of the material's internal microstructure in real time, like having a tactile sense, rather than operating blindly. This solves the problem of blind and inaccurate control of the compaction process caused by the inability of current servo presses to perceive the real-time deformation stage of the material.

[0016] 2. This invention also achieves the effect of adaptively deciding and triggering precisely matched micro-amplitude additional compaction commands, pressure holding optimization commands, or elastic recovery allow commands based on real-time calculated pressure decay rate by designing a decision logic subunit in the adaptive compaction control unit and its preset electrode deformation stage judgment algorithm. This further solves the problems of existing systems being unable to distinguish material deformation stages and having rigid control strategies, leading to over-compaction damaging the internal pore structure of the workpiece or under-compaction affecting density, thus improving the targeting and accuracy of the compaction process.

[0017] 3. This invention also designs a cyclic judgment subunit and a compaction target achievement judgment algorithm in the adaptive compaction control unit. After each control action is executed, the system automatically acquires the real-time thickness and density data of the electrode sheet and compares it with the final process target. Then, it intelligently controls the process to return to the pressure decay analysis subunit for the next cycle, or outputs a stop command to complete the compaction effect. This further solves the problem that the existing system lacks a perfect cyclic judgment mechanism, which leads to substandard compaction quality, high rework rate, and inability to guarantee the consistency of quality of each workpiece. It effectively reduces production losses and improves the product qualification rate.

[0018] 4. This invention also designs a multi-mode drive control unit and its force-position hybrid control drive algorithm in the drive and execution module. After receiving instructions from the core control decision module, it smoothly switches between force closed-loop control mode, position closed-loop control mode, and position locking mode. This drives the servo power mechanism and pressure actuator to precisely execute complex actions such as initial densification, position locking, micro-amplitude additional compaction, pressure holding optimization, and elastic recovery. This further solves the problems of existing systems having a single drive mode and inflexible switching, resulting in low action execution accuracy, slow response speed, and inability to achieve precise control with adaptive control instructions, ensuring the stable and precise execution of each compaction action. Attached Figure Description

[0019] Figure 1 This is an overall system block diagram of the present invention.

[0020] Figure 2 This is a flowchart of the overall method of the present invention.

[0021] Figure 3 This is a block diagram of the signal acquisition and processing module of the present invention.

[0022] Figure 4 This is a block diagram of the core control decision module of the present invention.

[0023] Figure 5 This is a block diagram of the driving and execution module of the present invention.

[0024] Figure 6 This is the core control decision flowchart of the present invention.

[0025] Figure 7 This is a flowchart of the adaptive compaction control of the present invention.

[0026] Figure 8 This is a flowchart of the driving and execution module of the present invention.

[0027] Figure 9 This is a block diagram of the human-computer interaction and parameter management module of the present invention.

[0028] Figure 10 This is a block diagram of the signal conditioning and calculation unit of the present invention.

[0029] Figure 11 This is a chart analyzing the pressure setpoint adjustment range of the present invention. Detailed Implementation

[0030] Example: Figures 1 to 10 As shown, the present invention relates to a fully closed-loop force / position hybrid control system for a servo pressure control system, comprising a signal acquisition and processing module, a core control decision module, a drive and execution module, and a human-machine interaction and parameter management module; The signal acquisition and processing module is used to acquire pressure feedback signals and position feedback signals from the pressure actuator in real time; The signal acquisition and processing module includes a high-precision pressure sensing unit, a high-resolution position sensing unit, and a signal conditioning and calculation unit, which together constitute an intelligent monitoring device for real-time sensing of the compaction process. The high-precision pressure sensing unit and the high-resolution position sensing unit are the core sensing components of the intelligent measuring instrument, used to detect the actual pressure and position values ​​applied to the workpiece in real time. The high-precision pressure sensing unit uses a strain gauge pressure sensor, which is set in the force flow path of the pressure roller assembly. Specifically, it is installed on the bearing seat of the pressure roller and contacts the electrode plate synchronously with the pressure roller. It is used to detect the actual pressure value applied by the pressure roller to the electrode plate in real time. In particular, it can accurately capture the pressure relaxation process in the position-locked state and capture the subtle changes in pressure decay. The high-resolution position sensing unit uses a grating ruler, which is installed on the rotating shaft of the pressure roller to detect the rotation angle and displacement of the pressure roller in real time, indirectly obtaining the real-time thickness of the electrode sheet, reflecting the degree of action of the pressure actuator on the electrode sheet, ensuring accurate monitoring of the electrode sheet thickness, and meeting the control requirements of the overall thickness consistency of the electrode sheet. The signal conditioning and calculation unit uses a dedicated signal processing chip, which includes a processor such as a digital signal processor (DSP), a microcontroller unit (MCU), or a field-programmable gate array (FPGA). Its core is adapted to the needs of sensor signal processing and real-time data calculation. The processor is electrically connected to the high-precision pressure sensing unit and the high-resolution position sensing unit through the SPI interface. First, the acquired raw sensing signals are filtered, amplified, and digitized to remove invalid signals caused by environmental interference and equipment vibration. Then, based on the processed pressure signal, the real-time pressure decay rate is calculated through a pressure decay rate algorithm, providing accurate data for the pressure decay analysis of the core control decision module and ensuring the accuracy of pressure decay characteristic judgment. The formula for the pressure decay rate algorithm is: ; in, for The real-time pressure decay rate reflects how quickly the pressure decays over time. for The real-time pressure value is collected by a high-precision pressure sensing unit. ， for Real-time pressure value at any given moment. The preset monitoring time window can be flexibly set through the human-computer interaction and parameter management module to capture subtle changes in pressure decay and ensure the accuracy of decay characteristic analysis.

[0031] The core control decision module is used to receive the processed feedback signal and output control commands based on the hybrid closed-loop control logic of force and position, including the adaptive compaction control unit; The adaptive compaction control unit monitors pressure decay characteristics through an intelligent monitoring device. During the compaction process of the pressure actuator on the workpiece, after reaching an initial compaction target, the pressure actuator is controlled to enter a position lock state and monitor pressure decay characteristics. Then, based on the different characteristic ranges of the pressure decay characteristics, adaptive decisions are made and corresponding fine-tuning control actions are triggered. The adaptive compaction control unit includes a pressure decay analysis subunit, a decision logic subunit, and a cyclic judgment subunit; The pressure decay analysis subunit is used to receive pressure decay rate data transmitted by the signal acquisition and processing module in real time. After the pressure actuator, i.e. the pressure roller assembly, enters the position locking state, it continuously records the pressure change curve over time, i.e. the pressure relaxation curve, and analyzes the pressure decay characteristics to accurately determine the deformation stage of the electrode sheet material: plastic compaction stage, viscoelastic relaxation stage, and elastic recovery stage. The decision logic subunit pre-stores a preset pressure decay rate threshold range, which can be set through the human-computer interaction and parameter management module to adapt to the compaction requirements of different types of electrode sheets. Based on the following electrode sheet deformation stage judgment algorithm, it achieves accurate judgment of the deformation stage: The algorithm formula for judging the deformation stage of the electrode sheet is as follows: ; in, The first threshold for pressure decay rate, The second threshold is set as the pressure decay rate. The specific values ​​of the first and second thresholds can be determined through conventional process adjustments based on the compaction and stress relaxation curve characteristics of the target electrode material. The core principle is that after the position is locked, the pressure signal monitored by the system will exhibit a change process from gradient decay to eventual stability. The purpose of the adjustment is to ensure that the set thresholds can accurately distinguish the different deformation stages of the material during this process. for The real-time pressure decay rate reflects how quickly the pressure decays over time. This indicates that the pressure decay is stabilizing, meaning the pressure change per unit time approaches 0.

[0032] Based on the above formula, when the pressure decay rate is less than or equal to the first threshold, it is determined that the electrode sheet is in the plastic compaction stage. At this time, a decision is made to trigger a micro-amplitude additional compaction command to further improve the density of the electrode sheet while avoiding over-compaction. When the pressure decay rate is greater than the first threshold and less than the second threshold, it is determined that the electrode sheet is in the viscoelastic relaxation stage. At this time, the pressure holding optimization command is triggered to maintain the position locked state, allowing the electrode sheet material to fully complete stress relaxation and structural reorganization. Using this pore optimization window, a connected pore network is actively induced to meet the core requirement of pore shape preservation. When the pressure decay rate is greater than or equal to the second threshold or the pressure decay tends to stabilize, the electrode sheet is determined to be in the elastic recovery stage. At this time, the elastic recovery allow command is triggered to provide the electrode sheet material with rebound space and further optimize the pore connectivity.

[0033] In the decision logic subunit, the addition of compaction instructions, pressure holding optimization instructions, and elastic recovery allow instructions constitutes a set of instructions for adaptive control of the viscoelastic deformation stage of the workpiece material. The loop judgment subunit is used to receive real-time thickness or density data of the electrode sheet transmitted by the signal acquisition and processing module after each control command is executed. It then uses a compaction target achievement judgment algorithm to determine whether the workpiece state has reached the final process target and controls whether the process returns to the pressure decay analysis subunit for the next loop. The compaction target achievement judgment algorithm includes a thickness target judgment algorithm and a density target judgment algorithm; The formula for the thickness target determination algorithm is as follows: ; in, for Real-time thickness of the electrode sheet The final target thickness of the electrode sheet, The allowable thickness deviation is used to control the consistency of electrode sheet thickness and is preset according to the electrode sheet specifications. The formula for the density target determination algorithm is as follows: ; in, for Real-time compaction density of the electrode sheet The final target compaction density of the electrode sheet, The density tolerance is used to control the compaction density of the electrode sheet to meet the standard, and is preset according to the material properties of the electrode sheet; If any of the above formulas is not satisfied, that is, if the deviation between the real-time thickness or density and the target value exceeds the allowable range, the control process returns to the pressure decay analysis subunit to perform the next round of monitoring, decision-making, and execution cycle. If all conditions are met, a stop command is output to complete the electrode compaction process, ensuring that the compaction quality meets the preset electrode compaction process requirements.

[0034] The drive and execution module includes a servo power mechanism and a pressure actuator (pressure roller assembly) driven by the servo power mechanism. It is used to receive control commands and drive the servo power mechanism to control the pressure actuator to perform corresponding actions, including preliminary densification, position locking, micro-amplitude additional compaction, pressure holding optimization, and elastic recovery allowance. The servo power mechanism uses a servo motor, which has controllable and highly responsive linear power output capability. It is mechanically connected to the pressure actuator (pressure roller assembly) through a reducer and coupling, providing stable power for the rotation and feeding of the pressure roller. The pressure actuator adopts a double pressure roller structure. The two pressure rollers are installed in parallel with an adjustable gap. This is used to convert the power of the servo power mechanism into a precise pressing action on the electrode sheet. The surface of the pressure rollers is coated with a wear-resistant coating to avoid damage to the surface of the electrode sheet, while ensuring uniform pressure transmission to meet the uniform compaction requirements of high compaction density electrode sheets. The drive and execution module also includes a multi-mode drive control unit; the multi-mode drive control unit uses a servo driver and is electrically connected to the core control decision module and the servo power mechanism respectively. It is used to receive control commands from the core control decision module and, based on the force-position hybrid control drive algorithm, seamlessly switch and drive between force closed-loop control mode, position closed-loop control mode and position locking mode to ensure the precise execution of each control action. The formula for the force-position hybrid control drive algorithm is: ; ; ; in, The output drive signal of the multi-mode drive control unit is used to control the action of the servo power mechanism. For thickness deviation, for Set the thickness at all times. for Real-time thickness This represents the rate of change of thickness deviation. For pressure deviation, for Set pressure at all times. for Real-time pressure This is the proportional coefficient for position closed-loop control. For the differential coefficients of the position closed-loop control, For the position closed-loop control, is the integral coefficient. The proportional coefficients for the force closed-loop control are all determined by adjusting the parameters of the servo motor and the pressure roller assembly. They can be determined by conventional parameter adjustment methods (such as PID parameter tuning method and trial and error method). example: System composition and process parameters: Servo power mechanism: adopts a rated torque of Rated speed is AC servo motor; Transmission and Actuation Mechanism: The servo motor uses a transmission ratio of... A precision planetary gear reducer, with a pair of diameters of The compaction roller (pressure actuator) is connected. The overall rigidity of the system (including frame, bearings, etc.) is approximately... ; Controlled object and target: The workpiece being processed is a lithium-ion battery negative electrode sheet, with an initial thickness of approximately The final target thickness of this process Set as The ultimate goal is compaction density. Set as ; Specific determination of control parameters: Position loop parameter tuning (determined) , , ): Set the system to pure position control mode (i.e., set the force control coefficient) With the pressure roller unloaded (not in contact with the workpiece), a range of [value] is given via the human-machine interface. Step thickness command; The critical proportionality method is used for debugging: First, the integral coefficient is adjusted. and differential coefficients Set to zero, then gradually increase the scaling factor. The value of the proportional coefficient is recorded until the system exhibits sustained, constant-amplitude oscillations. The critical value of the proportional coefficient at this point is then recorded. and oscillation period ; The initial theoretical values ​​of the position loop parameters were calculated using the Ziegler-Nichols empirical formula, serving as the starting point for debugging. Subsequently, actual electrode plates were introduced for load testing, and the integral and differential parameters were significantly optimized to obtain a stable and rapid response. Finally, a set of optimal parameters was determined as follows: ， ， ; Force control ring parameter tuning (determined) ): Set the system to pure force control mode (i.e., set the position loop coefficient) , , Control the pressure roller to contact the workpiece and establish a stable initial pressure, then give an amplitude of... The step pressure command gradually increases the force control proportional coefficient. Observe the system's pressure tracking response curve until a fast and stable tracking without oscillations is obtained. Finally, it is determined that: ; During a specific phase of incremental compaction control, select a particular moment. This demonstrates how the driving algorithm calculates the output driving signal based on real-time feedback values. ; The set value and sensor feedback value at this moment: Thickness setting value: The desired thickness target preset by the operator or host computer through the human-machine interaction and parameter management module, during the complete compaction process. It is a trajectory curve that rapidly approaches the target thickness from the initial thickness, i.e. , ; Real-time thickness feedback value: This value is detected and calculated in real time by a high-resolution position sensing unit in the signal acquisition and processing module. Specifically, it is installed on the rotating shaft of the pressure roller to detect the roller displacement and roller gap in real time. The current thickness of the electrode sheet can be determined by measuring the roller gap. , ; Thickness deviation change rate: It is a thickness deviation Regarding time The first derivative, i.e. This represents the instantaneous rate of change in thickness deviation, and its derivative is approximated in real time using the backward difference method. The system operates with a fixed sampling period. ,like Thickness deviation And through the formula Calculate its change, i.e. ; Thickness deviation integral value: thickness deviation The cumulative sum from the start of the control process to the current moment, i.e., within the sampling period, is acquired in real time by the system. and The value is used to calculate the instantaneous deviation. The trapezoidal numerical integration method is used, and the specific calculation formula is as follows: ,in, For the first Sampling time, The thickness deviation for each sampling period is discretely accumulated, and the integral value of the thickness deviation at the current moment is calculated. ; Pressure setpoint: This is a pre-set and stored value by the operator within the system. It is input and saved through the process parameter setting and storage unit in the human-machine interface and parameter management module. The desired pressure target is pre-set and stored for different electrode materials, target thicknesses, and process requirements. This value can be directly input as a constant. Its core function is to serve as the setpoint for the pressure closed loop, ensuring the achievement of the thickness target while providing direct pressure upper limit protection. This prevents excessive pressure applied in pursuit of thickness, which could damage the microstructure of the electrode active material coating or substrate. The pressure setpoint is determined within the equipment's safe pressure range (e.g., ...). This is the result of a series of process debugging experiments on the target electrode sheet. (See attached image.) Figure 11 As shown, the compaction density increases with increasing pressure, but the retention rate of the electrode's micropore structure decreases accordingly, and there is an optimal pressure point for thickness uniformity. Through comprehensive evaluation, the pressure value that simultaneously meets the requirements of target compaction density, pore structure retention rate, and thickness uniformity is selected as the pressure setpoint, thereby achieving synergistic optimization of high density and porosity preservation. ; The real-time pressure feedback value is detected in real time by a high-precision pressure sensing unit in the signal acquisition and processing module. Specifically, a strain gauge pressure sensor is used and mounted on the bearing housing of the pressure roller, directly located in the force flow path, to detect the actual pressure value applied by the pressure roller to the electrode plate in real time. ; Calculate thickness deviation and pressure deviation : ; ; Substitute all the above specific values ​​and the determined control parameters into the drive algorithm formula: ; The signal output by the force-position hybrid control drive algorithm Its physical unit is the volt (Volt). This signal, as a standardized voltage-type command, is sent by the core control decision module to the servo driver in the drive and execution module. The servo driver receives this signal. Upon receiving the voltage command, the system precisely and linearly converts it into the armature current that drives the servo motor, based on its internally preset current loop control and power amplification circuit. This current interacts with the magnetic field of the permanent magnet inside the servo motor, generating an electromagnetic torque proportional to it, measured in Newton-meters (N·m). This output torque, via mechanical transmission components such as reducers and couplings, is ultimately converted into a precise pressing force applied to the workpiece by the pressure actuator (pressure roller); This formula achieves force-position hybrid control by integrating feedback from position deviation (thickness deviation) and pressure deviation: When in position control mode Set the value to 0 to ensure thickness accuracy. When in force control mode , ,and Set the value to 0 to ensure stable pressure. When in location lock mode Keep it unchanged, by adjusting , ,and Maintain positional stability to ensure accurate monitoring of pressure decay characteristics; The specific action execution process strictly conforms to the adaptive compaction requirements of the high compaction density electrode sheet: The micro-amplitude additional compaction action is as follows: the multi-mode drive control unit releases the position lock state, switches to the position control mode, drives the pressure actuator (pressure roller assembly) to finely adjust the roller gap, so that the effect on the electrode sheet is increased by a preset micro displacement amount, and then re-enters the position lock state to continue to monitor the pressure decay characteristics to avoid over-compaction that could cause the pores to be crushed. The pressure holding optimization action is as follows: the multi-mode drive control unit maintains the position lock state and maintains the preset optimization holding time, allowing the electrode sheet material to fully complete stress relaxation and structural reorganization, and actively induces the formation of an ideal interconnected pore network; The elastic recovery allowable action is as follows: the multi-mode drive control unit switches to force control mode, reduces the current pressure value by a preset ratio and maintains it for a preset release time, providing space for the elastic recovery of the electrode material, further optimizing pore connectivity, and improving electrolyte wettability and ion transport efficiency.

[0035] The human-machine interaction and parameter management module includes a process parameter setting and storage unit and a real-time status display unit, which are used for setting, storing, recalling process parameters and displaying process information; The process parameter setting and storage unit adopts a touch operation panel. Operators can use this unit to set and store multiple sets of compaction process parameters adapted to different production conditions, including initial compaction target, final compaction target, pressure decay characteristic criterion threshold (first threshold, second threshold), and relevant parameters of each control action (micro-displacement, optimized holding time, pressure reduction ratio, release time, etc.). At the same time, multiple sets of process parameters can be stored to facilitate quick switching between different production conditions. The real-time status display unit uses a high-definition display screen to dynamically display real-time pressure curves, real-time position curves, pressure decay rate, current control stage, and cycle count information. Operators can monitor the compaction process in real time, promptly detect abnormalities and issue alarms, and facilitate process optimization and troubleshooting.

[0036] The embodiments disclosed in this invention are preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of this invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of this invention, they are all within the protection scope of this invention.

Claims

1. A fully closed-loop force / position hybrid control system for a servo pressure control system, characterized in that, It includes a signal acquisition and processing module, a core control decision module, a drive and execution module, and a human-machine interaction and parameter management module; The drive and execution module includes a servo power mechanism and a pressure execution mechanism driven by the servo power mechanism; The signal acquisition and processing module is used to acquire pressure feedback signals and position feedback signals from the pressure actuator in real time. The core control decision module is used to receive the processed feedback signal and output control commands based on the hybrid closed-loop control logic of force and position. It includes an adaptive compaction control unit, which is used to control the pressure actuator to enter a position lock state and monitor the pressure decay characteristics after an initial compaction target is reached during the process of the pressure actuator compacting the workpiece. Then, based on the different characteristic ranges of the pressure decay characteristics, it adaptively makes decisions and triggers corresponding fine-tuning control actions. The drive and execution module is used to receive control commands and drive the servo power mechanism to control the pressure actuator to perform corresponding actions, including preliminary densification action, position locking action, micro-amplitude additional compaction action, pressure holding optimization action, and elastic recovery allowance action. The human-computer interaction and parameter management module is used for setting, storing, recalling process parameters and displaying process information.

2. The fully closed-loop force / position hybrid control system of the servo pressure control system according to claim 1, characterized in that, The signal acquisition and processing module includes a high-precision pressure sensing unit, a high-resolution position sensing unit, and a signal conditioning and calculation unit. The high-precision pressure sensing unit is installed in the force flow path of the pressure actuator to detect the actual pressure value applied to the workpiece in real time. The high-resolution position sensing unit is used to detect the position value in real time, which reflects the degree of action of the pressure actuator on the workpiece. The signal conditioning and calculation unit is used to filter, amplify and digitize the original sensing signal, and calculate the real-time pressure decay rate through the pressure decay rate algorithm.

3. The fully closed-loop force / position hybrid control system of the servo pressure control system according to claim 2, characterized in that, The formula for the pressure decay rate algorithm is as follows: ； in, for Real-time pressure decay rate at any given moment for Real-time pressure value at any moment ， for Real-time pressure value at any given moment. This is the preset monitoring time window.

4. The fully closed-loop force / position hybrid control system of the servo pressure control system according to claim 1, characterized in that, The adaptive compaction control unit in the core control decision module includes a pressure decay analysis subunit, a decision logic subunit, and a loop judgment subunit. The pressure decay analysis subunit is used to calculate the pressure decay characteristics based on the signal provided by the signal acquisition and processing module when the position is locked. The decision logic subunit is used to compare the pressure attenuation characteristics with a preset threshold range, and generate corresponding control commands accordingly. The loop judgment subunit is used to determine whether the workpiece state has reached the final process target after executing the control command by using the compaction target achievement judgment algorithm, and to control whether the process returns to the pressure decay analysis subunit for the next loop.

5. The fully closed-loop force / position hybrid control system of the servo pressure control system according to claim 4, characterized in that, The decision logic subunit is configured as follows: When the pressure decay rate is less than or equal to the first threshold, the decision triggers a micro-amplitude additional compaction command. When the pressure decay rate is greater than the first threshold and less than the second threshold, the decision triggers a pressure holding optimization command. When the pressure decay rate is greater than or equal to the second threshold or the pressure decay tends to stabilize, the decision triggers the elastic recovery permission command.

6. The fully closed-loop force / position hybrid control system of the servo pressure control system according to claim 4, characterized in that, The compaction target achievement judgment algorithm includes a thickness target judgment algorithm and a density target judgment algorithm; The formula for the thickness target determination algorithm is as follows: ； in, for Real-time thickness of the electrode sheet The final target thickness of the electrode sheet, For thickness tolerance; The formula for the density target judgment algorithm is as follows: ； in, for Real-time compaction density of the electrode sheet The final target compaction density of the electrode sheet, This represents the allowable density deviation.

7. The fully closed-loop force / position hybrid control system of the servo pressure control system according to claim 1, characterized in that, The drive and execution module also includes a multi-mode drive control unit; The servo power mechanism is used to provide controllable, highly responsive linear or rotary power output; The pressure actuator is mechanically connected to the servo power mechanism to convert power into a precise pressing action on the workpiece; The multi-mode drive control unit is electrically connected to the core control decision module and the servo power mechanism, respectively. It is used to receive control commands and, based on the force-position hybrid control drive algorithm, seamlessly switch and drive between force closed-loop control mode, position closed-loop control mode and position locking mode to ensure the precise execution of each control action.

8. The fully closed-loop force / position hybrid control system of the servo pressure control system according to claim 7, characterized in that, The formula for the force-position hybrid control drive algorithm is as follows: ； ； ； in, The output drive signal of the multi-mode drive control unit For thickness deviation, for Set the thickness at all times. for Real-time thickness This represents the rate of change of thickness deviation. For pressure deviation, for Set pressure at all times. for Real-time pressure This is the proportional coefficient for position closed-loop control. For the differential coefficients of the position closed-loop control, For the position closed-loop control, is the integral coefficient. The proportional coefficient for closed-loop force control.

9. A fully closed-loop force / position hybrid control system for a servo pressure control system according to claim 7, characterized in that, The multi-mode drive control unit is configured to: When performing a micro-amplitude additional compaction action, the position lock state is released and the position control mode is switched, driving the pressure actuator to increase the degree of action by a preset micro-displacement, and then re-entering the position lock state; When performing pressure holding optimization, maintain the position locked state and maintain the preset optimization holding time; When performing the elastic recovery allowable action, switch to force control mode, reduce the current pressure value by a preset percentage, and maintain the preset release time.

10. A fully closed-loop force / position hybrid control system for a servo pressure control system according to claim 1, characterized in that, The human-computer interaction and parameter management module includes a process parameter setting and storage unit and a real-time status display unit; The process parameter setting and storage unit is used to set and store the initial target, the final target, the pressure decay characteristic criterion threshold, and the relevant parameters of each control action; The real-time status display unit is used to dynamically display the real-time pressure curve, real-time position curve, pressure decay rate, current control stage, and cycle count information.

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