Control methods and systems for automated production lines of sealing rings

Abstract

This application relates to the field of rubber product processing control technology, and discloses a control method and system for an automated production line of sealing rings. The control method for the automated production line of sealing rings includes: constructing a reference resistance curve for the equipment under no-load conditions; controlling a servo press to execute a micro-speed steady-state venting sequence and maintaining a position-locked state at the closing end; calculating the net rheological torque based on the reference curve, and extracting the contact displacement drift, in-situ vulcanization rate index, and stress relaxation rate; determining the filling stability and rheological state of the rubber compound based on the parameters, and generating process correction instructions. This invention, through a micro-speed testing and position-locking mechanism, accurately decouples physical and chemical characteristics from the servo torque signal, and utilizes multi-dimensional parameters to achieve closed-loop control of foreign matter risk, filling quality, and vulcanization degree, effectively solving the problem of quality instability caused by rubber compound fluctuations in sealing ring production.

Description

Technical Field

[0001] This invention relates to the field of rubber product processing control technology, specifically to a control method and system for automated production lines of sealing rings. Background Technology

[0002] As a critical basic component, the molding quality of sealing rings requires strict control over dimensional accuracy and material density. Current automated production lines mostly use servo presses or hydraulic presses for molding, with control strategies primarily relying on preset position or pressure thresholds. However, during the process of driving the mold to close, the total torque output by the press actually includes the rheological resistance generated by the deformation of the rubber compound, the mechanical friction of the equipment slide, and the viscous damping of the hydraulic medium. Existing control systems typically ignore the dynamic interference of the equipment's own background resistance or simply use a fixed value deduction, failing to effectively address the frictional drift caused by temperature increases or changes in lubrication conditions. This makes it difficult for the system to accurately extract minute rubber compound filling signals from mixed loads.

[0003] Furthermore, rubber materials are typical viscoelastic polymers, and their processing performance is highly susceptible to fluctuations in raw material batches and environmental thermal processes. Existing monitoring methods are often limited to judging peak pressure from a single dimension, lacking the ability to analyze the crosslinking rate and stress relaxation characteristics within the rubber compound online. This limitation makes it difficult for control systems to distinguish between resistance anomalies caused by different mechanisms such as early scorching of the material, insufficient mold temperature, or the incorporation of hard foreign matter. It also prevents the system from adaptively adjusting vulcanization time or heating temperature based on the actual rheological state of the rubber compound. When faced with fluctuations in raw material quality, issues such as under-vulcanization, over-vulcanization, or dimensional inconsistencies can easily arise, making it difficult to ensure the production consistency of high-precision sealing products.

[0004] Therefore, this invention proposes a control method and system for automated production lines of sealing rings to address the shortcomings of existing technologies. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a control method and system for automated production lines of sealing rings. It solves the problem in existing automated production lines of sealing rings that the inability to accurately decouple the rheological characteristics of the rubber material from the equipment friction background leads to inaccurate identification of abnormal states such as material scorching, under-sulfurization, and foreign matter, and the inability to adaptively adjust process parameters.

[0006] To achieve the above objectives, the present invention provides a control method for an automated production line of sealing rings, comprising the following steps:

[0007] Torque and displacement data during the exhaust stroke are collected under no-load conditions to construct a reference resistance curve that includes mechanical friction and hydraulic damping.

[0008] The servo press is controlled to perform multiple exhaust actions. During the closing process of each exhaust action, the speed is switched from a fast approach speed to a micro-speed test speed, and the position is locked after the last exhaust action is closed.

[0009] Based on the torque data at the micro-speed test and the torque attenuation data under the position lock-up state, the net rheological torque is calculated in combination with the reference resistance curve. The contact displacement drift reflecting the filling state of the rubber compound, the in-situ vulcanization rate index reflecting the curing rate, and the stress relaxation rate reflecting the viscoelasticity of the material are also calculated.

[0010] The filling stability is determined based on the contact displacement drift, the rheological state of the rubber compound is determined based on the combination of the in-situ vulcanization rate index and the stress relaxation rate, and a process correction instruction is generated based on the filling stability and the rheological state of the rubber compound.

[0011] Preferably, the step of constructing a reference resistance curve that includes mechanical friction and hydraulic damping includes:

[0012] The path of the exhaust stroke is divided into multiple small position intervals, and the collected time series data is mapped to the corresponding small position intervals.

[0013] The servo press is controlled to continuously execute multiple no-load cycles, and the arithmetic mean of the torque within each of the aforementioned minute position intervals is calculated.

[0014] The arithmetic mean is smoothed using a moving average filtering algorithm to generate the reference resistance curve that varies with position;

[0015] The equipment temperature or production cycle is monitored in real time. When the monitored temperature change exceeds the preset temperature drift threshold, the reference resistance curve is linearly compensated based on the viscosity-temperature characteristics.

[0016] Preferably, in the step of controlling the servo compressor to perform multiple exhaust actions, the logic regarding speed switching is as follows:

[0017] Define the mold closing direction as the direction in which the position coordinate value increases;

[0018] Determine the speed switching position, which is the mold fully closed position or the estimated material contact position minus the preset safety buffer distance;

[0019] The servo press is controlled to run at the rapid approach speed to the speed switching position, and then decelerates stepwise to the micro-speed test speed;

[0020] The setting of the safety buffer distance must ensure that the braking distance required for the servo press to decelerate from the rapid approach speed to the micro-speed test speed is less than the safety buffer distance, so as to ensure that the mold has entered the micro-speed state before contacting the rubber material.

[0021] Preferably, the step of controlling the servo compressor to perform multiple exhaust actions further includes:

[0022] After the speed command is switched, a preset steady-state setup delay is executed, which is greater than the step response adjustment time of the servo system.

[0023] Data acquisition is initiated after the steady-state establishment delay ends to ensure that the angular acceleration of the servo motor approaches zero at the time of acquisition, thereby eliminating the interference of inertial torque on the rheological resistance measurement.

[0024] Preferably, the step of calculating the contact displacement drift reflecting the filling state of the rubber compound includes:

[0025] The net rheological torque is obtained by subtracting the value of the reference resistance curve at the corresponding position from the total load torque collected in real time.

[0026] The first spatial derivative of the net rheological torque with respect to displacement is calculated to obtain the torque gradient, and the position where the torque gradient exceeds a preset gradient determination threshold is identified as the contact position.

[0027] The contact position of the first exhaust action and the contact position of the last exhaust action are identified respectively, and the difference between the contact position of the first exhaust action and the contact position of the last exhaust action is calculated to obtain the contact displacement drift.

[0028] Preferably, the step of calculating the in-situ vulcanization rate index, which reflects the curing rate, includes:

[0029] The linear compression interval after the contact position is selected on the net rheological torque curve;

[0030] Calculate the torque-displacement slopes of the first and last exhaust actions within the linear compression range to obtain the corresponding transient stiffness.

[0031] The difference between the transient stiffness of the last exhaust action and the transient stiffness of the first exhaust action is calculated, and the difference is divided by the time interval between the first and last exhaust actions to obtain the in-situ vulcanization rate index.

[0032] Preferably, the step of calculating the stress relaxation rate, which reflects the viscoelasticity of the material, includes:

[0033] In the position locked state, the servo control mode is switched to position closed-loop control to resist the rebound force of the rubber material and keep the mold position constant.

[0034] The initial peak torque at the start of position locking and the residual torque at the end of the preset locking time are collected.

[0035] Calculate the difference between the initial peak torque and the final residual torque, and divide the difference by the initial peak torque to obtain the stress relaxation rate.

[0036] Preferably, the steps of determining filling stability and identifying foreign object risk based on the contact displacement drift include:

[0037] The absolute value of the contact displacement drift is compared with a preset stability threshold. If the absolute value is greater than the stability threshold, it is determined that the filling is not up to standard, and the number of venting actions is increased until the absolute value is less than or equal to the stability threshold.

[0038] Simultaneously monitor the transient stiffness and the stress relaxation rate. If the transient stiffness is higher than the preset upper limit threshold for stiffness safety and the stress relaxation rate is lower than the preset lower limit threshold for relaxation rate, it is determined that there is a hard foreign object and an emergency stop protection command is triggered.

[0039] Preferably, the step of generating process correction instructions includes:

[0040] A two-dimensional orthogonal state space is constructed with the in-situ sulfurization rate index as the chemical kinetic dimension and the stress relaxation rate as the physical viscoelastic dimension.

[0041] If the current state point shows that the in-situ vulcanization rate index is higher than the preset upper limit of the in-situ vulcanization rate index and the stress relaxation rate is lower than the preset lower limit of the stress relaxation rate, it is determined to be a scorching state, and a correction command to reduce the heating temperature is generated.

[0042] If the current state point shows that the in-situ vulcanization rate index is lower than the preset lower limit of the in-situ vulcanization rate index and the stress relaxation rate is higher than the preset upper limit of the stress relaxation rate, it is determined to be an under-vulcanization state, and a correction command to extend the vulcanization time or increase the mold temperature is generated.

[0043] The present invention also provides a control system for an automated production line of sealing rings, comprising:

[0044] The data acquisition module is configured to acquire torque and displacement data during the exhaust stroke when the equipment is unloaded, and to construct a reference resistance curve that includes mechanical friction and hydraulic damping.

[0045] A servo unit is configured to drive a mold assembly to execute a micro-speed steady-state venting process sequence in response to control commands. The micro-speed steady-state venting process sequence includes switching from a rapid approach speed to a micro-speed test speed during the closing process and maintaining a position-locked state at the end of the closing process.

[0046] The decoupling module is configured to calculate the net rheological torque based on the torque data at the micro-speed test and the torque attenuation data under the position lock-up state, combined with the reference resistance curve, and extract the contact displacement drift, in-situ vulcanization rate index and stress relaxation rate.

[0047] The decision module is configured to determine the filling stability based on the contact displacement drift, determine the rheological state of the rubber compound based on the combination of the in-situ vulcanization rate index and the stress relaxation rate, and generate process correction instructions based on the filling stability and the rheological state of the rubber compound.

[0048] This invention provides a control method and system for an automated production line of sealing rings. It has the following beneficial effects:

[0049] 1. This invention effectively solves the problem of inherent friction and fluid damping masking the rheological signals of trace amounts of rubber material in hydraulic servo presses by constructing a reference resistance curve in the no-load state, incorporating mechanical friction and hydraulic damping, and performing differential calculations based on position mapping in actual production. This method physically decouples equipment characteristics from material properties, enabling the system to accurately extract the net rheological torque reflecting the degree of rubber material filling and cross-linking state directly from the torque signal of the servo motor without adding external sensors, thus improving the signal-to-noise ratio of data acquisition and control accuracy.

[0050] 2. This invention employs a unique process sequence that transitions from rapid approach testing to low-speed testing and ultimately maintains position locking, coupled with a steady-state establishment delay mechanism, eliminating inertial impacts and hydrodynamic pressure interference during speed changes. Through this quasi-static testing environment, the system can simultaneously acquire the in-situ vulcanization rate index, reflecting the chemical crosslinking rate, and the stress relaxation rate, reflecting physical viscoelasticity, within a single molding cycle. This enables the control system to perform online analysis of the material's microstructure evolution, promptly identifying early scorching or foreign matter contamination risks in the rubber compound, thus overcoming the blind spots of traditional single pressure threshold monitoring.

[0051] 3. This invention utilizes the in-situ vulcanization rate index and stress relaxation rate to construct a two-dimensional orthogonal state space, achieving accurate classification and adaptive compensation for the causes of production anomalies. The system can clearly distinguish between material scorching caused by excessively long thermal history and under-vulcanization caused by insufficient thermal energy, and accordingly generate differentiated correction commands for heating temperature or vulcanization time. This closed-loop control mechanism avoids erroneous parameter adjustments caused by misjudging the type of anomaly in traditional methods, ensuring the quality consistency of sealing ring products under raw material batch fluctuations. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the control system structure for an automated production line of sealing rings according to the present invention;

[0053] Figure 2 This is a flowchart of the control method for an automated production line of sealing rings according to the present invention;

[0054] Figure 3 This is a schematic diagram of the multidimensional rheological feature parameter extraction process of the present invention;

[0055] Figure 4 This is a schematic diagram of the multi-level decoupling determination and closed-loop control process of the present invention;

[0056] Figure 5 This is a schematic diagram illustrating the background friction deduction and net torque extraction principle of the present invention.

[0057] Among them, 11 is the servo unit; 12 is the mold assembly; 13 is the sensing unit; 14 is the controller; 141 is the acquisition module; 142 is the decoupling module; and 143 is the decision module. Detailed Implementation

[0058] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] See attached document Figure 1 , Figure 1 This is a schematic diagram of a control system structure for an automated production line of sealing rings according to an embodiment of the present invention. The present invention provides a control system for an automated production line of sealing rings, the control system including a hardware execution part and a logic control part.

[0060] The hardware execution section includes a servo unit 11, a mold assembly 12, and a sensing unit 13.

[0061] The servo unit 11 is configured to output controllable motion and torque to drive the mold assembly 12 to perform opening and closing actions. The servo unit 11 integrates a torque controller (e.g., a current loop PID controller), which monitors and adjusts the output torque of the motor in real time. The servo unit 11 can be a fully electric servo screw press or a servo motor-driven pump-controlled hydraulic press system.

[0062] The sensing unit 13 includes a position sensor and a torque sensor. The position sensor is set on the motion axis of the mold assembly 12, such as a grating ruler, a magnetostrictive displacement sensor, or an absolute encoder built into the servo motor, to acquire the absolute position coordinates of the mold. The torque sensor is coupled to the servo unit 11 to acquire the load resistance torque signal. The torque sensor can be a strain gauge torque sensor installed on the transmission chain, or a current monitoring unit inside the servo driver, which obtains the torque value by converting the current to the torque constant.

[0063] The logic control section operates within controller 14. Controller 14 communicates with servo unit 11 and sensing unit 13 via an industrial fieldbus (e.g., EtherCAT, Profinet, or CANopen). Controller 14 can be a programmable logic controller (PLC), an industrial personal computer (IPC), or an embedded control system. Controller 14 includes a data acquisition module 141, a decoupling module 142, and a decision module 143, as well as a storage module for data storage and a display module for human-machine interaction.

[0064] The acquisition module 141 is used for signal synchronization and preprocessing. The acquisition module 141 includes a synchronization unit and a reference unit; the synchronization unit aligns the position signal and torque signal on the time axis and achieves microsecond-level synchronization through hardware interrupt or high-frequency sampling interpolation; the reference unit acquires the mechanical friction and hydraulic damping characteristics under the no-load state of the equipment, generates a reference friction model and stores it in the storage module.

[0065] The storage module is configured to store preset temperature drift thresholds, stiffness safety upper limit thresholds, stress relaxation rate lower limit thresholds, standard process window data, and historical production data.

[0066] The decoupling module 142 is used to extract physical characteristic parameters. The decoupling module 142 includes contact elements, stiffness elements, and relaxation elements; the contact elements identify the contact position based on the spatial gradient of the net torque signal and calculate the filling displacement drift; the stiffness elements calculate the transient stiffness value in the micro-speed section of the exhaust stroke and calculate the in-situ vulcanization rate exponent based on the time interval; the relaxation elements monitor the torque decay characteristics and calculate the stress relaxation rate during the pressure holding stage.

[0067] The decision module 143 is used to adjust process instructions. The decision module 143 includes a protection unit, a filling unit, and a compensation unit; the protection unit compares the peak torque with the stress relaxation rate to identify foreign objects; the filling unit determines whether to add venting based on the filling displacement drift; the compensation unit performs orthogonal analysis on the in-situ vulcanization rate index and the stress relaxation rate to generate correction instructions for vulcanization time, clamping force, or heating temperature, and sends the correction instructions to the servo unit 11 or the temperature control system for execution via the bus.

[0068] See attached document Figure 2, Figure 2 This is a flowchart of a control method for an automated production line of sealing rings according to an embodiment of the present invention. The present invention provides a control method for an automated production line of sealing rings, comprising the following steps:

[0069] S100, establish a tribological benchmark model for the equipment; collect the torque and displacement relationship during the exhaust stroke under no-load conditions to construct a benchmark resistance curve that includes mechanical friction and hydraulic damping;

[0070] S200 executes a micro-speed steady-state exhaust process sequence; controls the servo press to perform multiple exhaust actions, performs a step deceleration to a micro-speed state at the closing end of each exhaust action, and maintains a position locked state after the last exhaust action closes.

[0071] S300 extracts multidimensional rheological characteristic parameters; based on real-time acquired torque and displacement data, it calculates the contact displacement drift reflecting the filling state of the rubber compound, the in-situ vulcanization rate index reflecting the curing rate, and the stress relaxation rate reflecting the viscoelasticity of the material.

[0072] The S400 performs multi-level decoupling judgment and closed-loop control; it identifies foreign matter risks, filling stability and rubber rheological state based on characteristic parameters, and adaptively adjusts vulcanization process parameters or triggers protection commands.

[0073] To further clarify the implementation of each technical aspect of the present invention, the following will provide a detailed description of the implementation of each functional module involved above and its internal processing flow.

[0074] In step S100, a tribological reference model of the equipment is established. This step is mainly performed by the reference unit in the acquisition module 141. Based on the background subtraction principle in rheological detection, considering that the total torque output of the servo press during operation includes not only the rheological resistance generated by the deformation of the rubber material, but also the mechanical friction of the equipment itself and the viscous damping generated by hydraulic oil or grease; since mechanical friction usually changes with position, while viscous damping changes with speed and temperature, it is not possible to simply use a single constant for subtraction; this embodiment establishes a reference resistance curve that changes with position to decouple the inherent characteristics of the equipment from the total load, thereby improving the signal-to-noise ratio of subsequent detection of minute changes in the rubber material. The specific process of establishing the tribological reference model of the equipment includes:

[0075] S110, trigger no-load cycle sampling. Controller 14 monitors the equipment's operating status signal in real time. In this embodiment, when controller 14 receives a mold replacement completion signal, a cold start preheating command, or reaches a preset calibration cycle, it confirms that the mold cavity is in a state without material filling. Controller 14 sends a no-load operation command to servo unit 11, driving mold assembly 12 to perform a complete venting and opening / closing action. During this process, servo unit 11 strictly follows the speed-position curve set in the production process to drive the moving mold towards the fixed mold, maintaining kinematic parameters completely consistent with actual production, until the fully closed position is reached.

[0076] S120, constructing a full-stroke data mapping. During no-load operation, the sensing unit 13 synchronously collects the real-time position data of the mold and the output torque data of the servo unit 11 at a preset sampling frequency. The sampling frequency is set to no less than 500Hz to prevent high-frequency friction noise from being aliased. Considering that discrete sampling points with different sampling periods are difficult to precisely coincide on the position coordinates, the reference unit first performs spatial discretization processing on the stroke, dividing the path from the contact start point to the closing end point into multiple small position intervals (e.g., each interval is 0.1mm). The reference unit maps the collected time series data (t,x,T) to the corresponding position intervals. For multiple sampling points falling within the same interval, their arithmetic mean is taken as the original torque value at that position.

[0077] S130, Generate a reference resistance curve. To eliminate random mechanical vibration noise and sensor signal fluctuations within a single sampling period, controller 14 controls servo unit 11 to continuously execute M idle cycles, where M is an integer between 3 and 10. The reference unit performs statistical processing on the data collected in multiple cycles, calculates the arithmetic mean at each location point, and smooths the curve using a moving average filtering algorithm with a sliding window length of L (e.g., L = 5 sampling points), thereby constructing a standardized reference resistance curve. The calculation process is shown in the following formula:

[0078] ;

[0079] In the formula, Indicates the position of displacement The reference resistance torque at the location; Indicates the total number of idle cycles; Indicates the first Displacement position during the second no-load cycle The instantaneous torque value after spatial mapping. Reference resistance curve. It is stored in the non-volatile memory of controller 14 as the minuend for subsequent calculation of net rheological resistance.

[0080] S140, Perform dynamic compensation of the model. Considering that the viscosity of hydraulic oil or grease decreases as the equipment operating temperature increases, causing background damping drift, the reference unit performs periodic calibration. Controller 14 monitors the hydraulic system or ambient temperature in real time. In this embodiment, when the monitored temperature change... When the preset temperature drift threshold (e.g., 5°C) is exceeded, or when the number of continuous production cycles reaches the preset verification threshold (e.g., 500 cycles), the reference unit activates the compensation mechanism. If the conditions for resuming no-load operation are not met, the reference unit calls a linear compensation model based on viscosity-temperature characteristics to correct the reference curve.

[0081] ;

[0082] In the formula, This is the corrected reference resistance torque; The viscosity-temperature correction factor for the equipment is determined in advance, and its value is usually between 0.001 / ℃ and 0.005 / ℃, depending on the viscosity index of the hydraulic oil. This represents the difference between the current temperature and the temperature at which the baseline model was established. Dynamic compensation ensures that the baseline model accurately represents the current mechanical state of the equipment throughout long-term production processes.

[0083] See attached document Figure 2 In step S200, a micro-speed steady-state venting process sequence is executed. This step is mainly completed by the controller 14 sending motion control commands to the servo unit 11. Based on the rheological properties of polymer materials, the apparent viscosity of the adhesive usually changes with the shear rate. In order to obtain static physical characteristics that can truly reflect the filling state and curing degree of the adhesive, it is necessary to eliminate the interference of dynamic water pressure at high flow rates and the interference of inertial torque during the speed change process. This embodiment constructs a two-stage velocity profile of "rapid approach - micro-speed detection" and introduces a dynamic stability window before sampling to ensure that the torque signal obtained by the sensor only contains the rheological resistance of the adhesive and the friction of the equipment foundation. The specific implementation process includes:

[0084] S210, execute segmented speed planning. The controller 14, based on the mold cavity depth and the preset material thickness, spatially divides the venting closing stroke into a rapid approach segment and a micro-speed sampling segment. In this embodiment, during the rapid approach segment, the controller 14 instructs the servo unit 11 to approach at a preset speed... (For example, 100mm / s to 300mm / s) The moving mold is driven to move towards the fixed mold to reduce the loss of non-process time. The controller 14 monitors the mold position in real time, and when the moving mold reaches the preset switching position... At that time, it is determined that the micro-sampling segment has been entered. In this embodiment, the mold closing direction is defined as the direction in which the position coordinate value increases, and the position is switched. The method for determining it is as follows: .in, This refers to the zero point where the mold is fully closed or the estimated highest contact point of the rubber material. For a safe buffer distance, the value ranges from 2mm to 10mm. The physical meaning of this formula is to ensure that the servo motor has sufficient distance from the estimated contact point. The servo motor begins to decelerate upon reaching a certain distance. Furthermore, this safety buffer distance must be set to ensure that the servo motor... Decelerate to The required braking distance is less than This ensures that the mold has completed the speed switch before contacting the rubber material, avoiding high-energy impact on the rubber material that could cause scorching or overflow.

[0085] S220 executes step deceleration and steady-state establishment. When the moving mode reaches the switching position... At that time, controller 14 sends a speed step command to change the drive speed from the approach speed. Forced to reduce to a constant micro-speed test rate In this embodiment, the micro-speed test speed The value range is set to 0.5 mm / s to 5 mm / s. The reason for choosing this micro-speed range is that at this speed, the flow of the rubber compound is close to quasi-static deformation, the viscosity damping of the hydraulic oil is at a low level and the linearity is good, which is beneficial to improving the signal-to-noise ratio.

[0086] At the moment of speed switching, the servo motor and mechanical transmission mechanism will generate inertial torque peaks and mechanical oscillations due to momentum changes. To eliminate this inertial interference, the controller 14 does not immediately start data acquisition after the speed command switch, but instead executes a preset steady-state establishment delay. Steady-state establishment delay The duration setting needs to be greater than the step response adjustment time of the servo system, typically set to 50ms to 200ms, or the time required for the servo position tracking error to converge to a preset accuracy range (e.g., ±0.01mm). The physical principle of introducing steady-state setup delay is based on the following servo system dynamic equilibrium equation:

[0087] ;

[0088] In the formula, This refers to the real-time output torque of the servo motor. The torque of the rheological resistance of the rubber compound to be measured; This is the system's fundamental frictional torque; This is the system's equivalent moment of inertia converted to the motor shaft; This represents the angular velocity of the motor. Angular acceleration. During the variable or oscillating phase, angular acceleration... At this time, the inertial term It accounts for a large proportion of the total output torque, thus masking the weak rheological resistance torque. Establish a steady-state delay. Waiting for the servo system to complete PID adjustment and enter a uniform motion state, so that the angular acceleration at the sampling time... At this point, the dynamic equations simplify to This achieves physical layer decoupling of the rheological resistance signal, providing a low-noise data foundation for the accurate extraction of subsequent feature parameters.

[0089] S230, perform multi-cycle venting. Controller 14 is configured with a preset number of venting cycles N, which is typically set to 3 to 8 times. In this embodiment, the number of cycles is set based on the migration rate of bubbles in the rubber compound and the shear heating effect. Too few cycles will not completely vent deep gases, while too many cycles will cause the rubber compound to scorch prematurely. Controller 14 drives servo unit 11 to continuously execute the "mold opening-mold closing" cycle N times. In the closing phase of each cycle, the segmented speed planning and step deceleration logic in steps S210 and S220 above are repeated.

[0090] Specifically, during each venting and closing process, when the mold reaches the switching position... At that time, the servo motors were strictly switched to the micro-speed test speed. And maintain a steady state until the mold closes to the preset venting endpoint position. At each point where the exhaust reaches its final position. Afterwards, controller 14 records the torque value at that moment, and then drives the mold to quickly retract to the venting open position. In this embodiment, the exhaust opening position... The determination method follows the following formula:

[0091] ;

[0092] In the formula, This refers to the free filling height of the rubber compound; For effective venting, a clearance of 5mm to 20mm is used. This setting ensures that the mold cavity is fully open and connected to the outside atmosphere with each retraction, breaking the vacuum negative pressure state inside the cavity and allowing the compressed gas inside the rubber to expand and escape rapidly. By ensuring high consistency of kinematic parameters (speed, position, temperature environment) during the micro-speed detection phase in each cycle, it is ensured that the torque differences collected between different cycles originate solely from changes in the physicochemical state of the rubber itself, i.e., the gradual filling and early cross-linking reaction of the rubber.

[0093] S240, execute end position locking. After completing the Nth (i.e., the last) exhaust action and reaching the exhaust endpoint position. At that instant, the controller 14 does not perform the usual pressure holding or retraction actions, but immediately switches to the servo control mode and enters the position lock state. In this embodiment, position lock means that the controller 14 switches the servo loop to a high-gain position control mode, and keeps the target position constantly set at the current exhaust endpoint position. And force the speed command to be set to zero.

[0094] The physical significance of position locking lies in constructing constant strain boundary conditions. According to the Maxwell model of polymer rheology, under constant strain conditions, the internal stress of a viscoelastic material decays exponentially with time. In this state, the servo unit 11 adjusts its output current in real time based on feedback from the position encoder to generate the necessary reverse braking torque to resist the rebound force of the rubber compound, thereby strictly limiting the mold position. Within the tolerance range. Among them, The position locking tolerance is set to the minimum resolution of the servo encoder or no greater than 0.005mm. The position locking state is maintained for a preset locking time. that time Set to 2 to 10 seconds. The basis for setting this duration is that the time window needs to cover the time required for the main stress relaxation physical process of the polymer chain segments of the rubber, which is usually 1 to 3 times the material relaxation time.

[0095] During the position locking period, since the mold geometry remains unchanged, the torque change collected by sensing unit 13 not only reflects the static rebound force of the rubber compound but also directly characterizes the viscoelastic characteristics of the material's internal stress decaying over time. The data acquisition in this process follows the sampling logic to form a stress relaxation dataset. :

[0096] ;

[0097] In the formula, This is the start time for entering position locking; To lock the duration; For a moment Real-time torque output by the servo motor; For a moment Actual location feedback; Lock the target's location; To allow for positional tolerance, this active closed-loop positional control eliminates the interference of slight positional retraction caused by oil compressibility or valve leakage during the pressure holding process of traditional hydraulic presses on the rheological data, ensuring the accuracy of the physical model for subsequent stress relaxation rate calculation.

[0098] See attached document Figure 3In step S300, multidimensional rheological characteristic parameters are extracted. This step is mainly performed by the decoupling module 142 and its internal contact units. Based on the high-precision position-torque data sequence obtained in the aforementioned steps, this embodiment employs a multidimensional decoupling algorithm based on a physical model to separate independent physical indicators characterizing the rheological state of the rubber compound from the mixed mechanical load signals. The physical basis of this method is that the mechanical friction and viscous damping of equipment typically exhibit low-frequency characteristics that change gradually with position or velocity, while the contact and phase change processes of the rubber compound will produce step changes in stiffness or stress at specific spatial locations. The specific implementation process includes:

[0099] S310, performs net resistance difference calculation. Decoupling module 142 first calls the pre-stored equipment tribological reference model. Background subtraction is performed on the real-time torque sequence acquired during the micro-sampling stage. Since there may be slight deviations in spatial coordinates between the discrete position points acquired in real-time and those stored in the reference curve, direct subtraction would lead to calculation errors. In this embodiment, the decoupling module 142 first uses a linear interpolation algorithm to map the real-time torque data to a position coordinate system completely consistent with the reference model. Subsequently, the net rheological torque after eliminating equipment friction is calculated using the following formula. :

[0100] ;

[0101] In the formula, For the displacement position The net rheological torque at the point of application is a physical quantity that eliminates the inherent Coulomb friction and viscous damping of the equipment and only reflects the rheological resistance of the rubber material to the mold closing motion. The total load torque is the actual data collected by the sensor and processed by a low-pass filter. This represents the reference friction torque at the corresponding position. In this embodiment, this differential calculation eliminates the systematic additive error introduced by uneven lubrication of the guide post or fluctuations in hydraulic oil temperature, ensuring the accuracy of the signal source for subsequent feature extraction.

[0102] See attached document Figure 5 , Figure 5 The graph visually illustrates the extraction principle of the net rheological resistance. The horizontal axis represents the mold displacement x (unit: mm), and the vertical axis represents the output torque T of the servo motor (unit: N·m). The curve shown by the dashed line in the graph... The tribological reference model of the equipment established in step S100 reflects the fluctuation characteristics of mechanical friction with position under no-load conditions; the curve shown by the solid line This curve represents the total load torque actually collected during the low-speed exhaust process, at the contact position. Previously, it largely coincided with the baseline curve, but rose rapidly after contact with the rubber compound. The curve shown by the thick solid line in the figure... This is the net rheological torque curve obtained after differential calculation of the two. It can be seen that, by subtracting background friction, the curve... In the non-contact section (0 to...) The system was calibrated to near the zero baseline, thereby eliminating low-frequency noise interference from the mechanical system and enabling subsequent adjustments to the contact points. and exhaust endpoint The feature extraction of the resistance of the rubber compound is more accurate.

[0103] S320, calculates contact displacement and fill factor. The contact element is based on net rheological torque. The spatial distribution characteristics are used to identify the precise contact point between the mold and the rubber compound. This embodiment employs the "spatial gradient mutation method" for identification to overcome the problem of recognition lag or false triggering that easily occurs when the hardness of the rubber compound changes, which is common with traditional fixed threshold methods. The contact unit first calculates the first spatial derivative of the net torque with respect to displacement, i.e., the torque gradient. As shown in the following formula:

[0104] ;

[0105] In the formula, For position Spatial torque gradient at the location; and These are the net torque values ​​at the current sampling point and the previous sampling point, respectively; The sampling space step size is determined by the sampling frequency and the micro-speed test speed.

[0106] The contact unit iterates through the gradient data of the entire stroke and selects the first element that meets the condition. The position is marked as the contact position. .in, This is the gradient determination threshold. In this embodiment, the threshold is determined by: statistically analyzing the slow-speed operation phase during the idle cycle (i.e., corresponding to...). to The standard deviation of the gradient of the benchmark resistance curve (within the range) ,Pick .coefficient The value ranges from 3 to 5 (based on the 3σ criterion) to ensure that the contact signal can be statistically significantly distinguished from the mechanical background noise.

[0107] Furthermore, in order to quantify the flow and filling state of the rubber compound during the multi-cycle venting process, the contact unit extracts the contact position of the first venting cycle. Contact position with the Nth exhaust cycle And calculate the filling displacement drift. :

[0108] ;

[0109] In the formula, To fill the displacement drift; The contact position identified during the last exhaust action; This refers to the contact position identified during the first venting action. In this embodiment, the mold closing direction is defined as the positive direction of the position coordinate system. Under this definition, if... This indicates that the contact position value has increased (i.e., the contact point has shifted backward), reflecting that the rubber material has softened and flowed during the venting process and filled the mold cavity more deeply; if This indicates that the rubber compound has reached saturation or its flowability is limited; if This indicates that there may be early scorching of the rubber compound leading to volume expansion or abnormally increased resilience. This indicator... It can be used directly as a quantitative basis for evaluating the flowability and air release effect of rubber compounds.

[0110] This step aims to establish a mapping relationship between mechanical signals and the evolution of the material's microstructure by analyzing the mechanical response of the rubber compound under different physical states. The physical principle is that as the vulcanization reaction proceeds, chemical cross-linking bonds form between polymer chains, leading to a significant increase in the material's macroscopic modulus (stiffness). Simultaneously, the slippage of molecular chain segments is restricted, viscous flow characteristics weaken, and elastic characteristics enhance, resulting in a decrease in stress relaxation amplitude. Based on this principle, this embodiment achieves a quantitative characterization of the vulcanization kinetics of the rubber compound. The specific implementation process includes:

[0111] S330, calculates the in-situ vulcanization rate exponent. The stiffness element is based on the contact positions identified by the aforementioned contact element. In net rheological torque A linear compression interval is selected from the curve. In this embodiment, the selection range of this linear compression interval is defined as follows: ,in This is the initial offset (e.g., 0.5mm). The ending offset (e.g., 1.5mm). The starting offset. The setting is to avoid the non-linear adjustment zone caused by the unevenness of the rubber surface at the moment of contact; termination offset The setting is to limit the amount of deformation, ensure that the stress state of the rubber compound is within the range of approximately linear elastic deformation, and avoid geometric nonlinear interference caused by large deformation.

[0112] Based on this, the stiffness element extracts the torque-displacement slope of the first and Nth exhaust cycles within this linear interval, i.e., the transient stiffness. The calculation formula is as follows:

[0113] ;

[0114] In the formula, and These are the starting and ending coordinates of the linear compression interval, respectively. and This corresponds to the net torque value. The stiffness for the first cycle is obtained. Stiffness of the Nth cycle Then, the stiffness element, taking into account the physical time interval between the two measurements, calculates the in-situ sulfurization rate index (ICRI):

[0115] ;

[0116] In the formula, It is the in-situ sulfidation rate index, and its physical unit is N·m / (mm·s); The transient stiffness is measured during the Nth exhaust cycle; The transient stiffness was measured during the first exhaust cycle. The timestamp for the time of the Nth cycle stiffness calculation; This is the timestamp of the first cyclic stiffness calculation. This index... It directly reflects the rate of increase of the rubber compound modulus over time.

[0117] In this embodiment, for The determination is made using a dynamic threshold comparison method. A preset scorch safety threshold is used. The method was determined through experimental calibration: the scorch time of the same batch of rubber compounds at the same temperature was measured on a standard vulcanizing apparatus. (For example, Mooney scorch), take the modulus growth rate corresponding to that time point as the benchmark and multiply it by a safety factor (e.g., 0.8). If the calculated... The controller determines that the rubber compound has too high activity and there is a risk of early scorching. It then issues an instruction to adjust the subsequent mold closing speed or reduce the barrel temperature to prevent early cross-linking before the filling is completed.

[0118] S340, calculate the stress relaxation rate. The relaxed element is applied to the stress relaxation dataset generated in step S240. Analysis was conducted. During the position-locking stage, due to conformational rearrangement of the polymer chain segments in the adhesive, the internal stress gradually decreases over time. Specifically, the relaxation unit extracts the start time of position-locking. initial peak torque and the end time of location locking Termination residual torque To eliminate the impact of high-frequency noise on single-point sampling, in this embodiment, and All values ​​are calculated using the arithmetic mean of a short-time window (e.g., ±20 ms) centered on the target time. Subsequently, the normalized stress relaxation rate is calculated for the relaxation element using the following formula. :

[0119] ;

[0120] In the formula, The stress relaxation rate is expressed as a percentage. The initial rheological torque at the moment of position locking; For the time after locking The remaining rheostat torque after that. This parameter There is a negative correlation between the crosslinking density and the crosslinking density of the rubber compound: uncured raw rubber exhibits significant viscous flow characteristics, a large stress attenuation range, and corresponds to higher... Values ​​(typically greater than 40%); however, as the degree of vulcanization deepens, a three-dimensional network structure is formed, significantly enhancing the material's elasticity and reducing the stress attenuation amplitude, corresponding to lower values. Value. The system will calculate it in real time. The value is compared with the preset process standard curve to serve as a non-destructive testing basis for judging the uniformity of rubber compound mixing and the current degree of curing.

[0121] See attached document Figure 4 In step S400, the logic of multi-level decoupling judgment and closed-loop control is further included. This step is executed by the decision module 143 in the controller 14 and its internal protection unit and filling unit. This step is based on the physical principle that different materials have drastically different mechanical response characteristics: rubber material, as a typical viscoelastic body, has both the energy storage characteristics of a spring and the energy dissipation characteristics of a damper when compressed, exhibiting a significant stress relaxation phenomenon, that is, the internal stress decays over time while maintaining constant strain; while hard foreign objects such as metal inserts or abandoned tools are approximately ideal elastic bodies, with extremely high stiffness and almost no stress relaxation. Based on the physical feature parameters extracted in step S300, this embodiment classifies and judges the current molding state and generates real-time motion control commands accordingly. The specific implementation process includes:

[0122] S410 performs foreign object detection and safety protection. The protection unit is responsible for monitoring abnormal impedance during the mold closing process to distinguish between normal material hardness fluctuations and abnormal hard foreign object obstructions. This embodiment uses a "stiffness-relaxation joint judgment model" for foreign object detection to avoid false alarms caused by the single stiffness judgment method when processing low-temperature hard materials.

[0123] Specifically, the protection unit monitors the current transient stiffness in real time. With stress relaxation rate The presence of foreign object risk is determined when the following joint logical conditions are met:

[0124] ;

[0125] In the formula, This is the upper limit threshold for stiffness safety; This is the lower limit threshold for relaxation rate; Represents the logical AND operation.

[0126] In this embodiment, the stiffness safety upper limit threshold is... The method for determining the stiffness is as follows: Measure the stiffness value of the raw rubber compound at room temperature, and take 1.2 to 1.5 times this value. The physical basis for this setting is that room temperature raw rubber is usually in its hardest state that may occur during processing; responses with stiffness exceeding this are highly likely to be non-rubber materials. Relaxation rate lower limit threshold. The method for determining this is as follows: measure the minimum relaxation rate of the rubber compound in a fully vulcanized state and take 50% of that value, usually set at 5% to 10%. The physical basis for this setting is that even fully cured rubber retains a certain degree of viscous relaxation characteristics, while the relaxation rate of metallic foreign matter theoretically approaches zero.

[0127] Once the above logical conditions are met, the protection unit immediately triggers an emergency stop protection command, driving the servo unit 11 to perform an emergency stop with maximum reverse torque and retract to the mold opening position, thereby blocking the mold closing force within the micron-level deformation range and avoiding permanent indentation damage to the mold cavity surface.

[0128] S420 performs fill stability check and retry. The fill cell is based on the fill displacement drift. The absolute value of the value is used to determine whether the rubber compound has reached a thermodynamic and rheological equilibrium state within the mold cavity. An excessively high value indicates that the rubber compound still exhibits significant flow migration or bubble collapse during repeated degassing, and the current filling state is not yet stable.

[0129] The filled cell will calculate the filled displacement drift amount. Compared with the preset stability threshold A comparison is performed. In this embodiment, the stability threshold... The thickness tolerance zone is determined based on the final product's thickness dimensional tolerance, and is set to 10% to 20% of the product's thickness tolerance value. For example, if the product's thickness tolerance is 0.2 mm, then... Take a thickness of 0.02 mm to 0.04 mm. When the conditions are met... When the filling unit determines that the filling is not up to standard, it automatically generates an additional exhaust command.

[0130] At this point, controller 14 adds to the number of cycles N set in the current process recipe. The next exhaust action updates the remaining cycle count. In this embodiment, the additional count... The maximum number of retries is typically set to 1 or 2, and the system has a maximum limit on the number of retries. (For example, 3 times) to prevent infinite loops caused by system failures. After performing the additional action, the system will re-enter steps S230 and S300 to collect data again and calculate new data. until satisfied Through this closed-loop feedback mechanism, the system can adaptively compensate for differences in filling performance caused by batch fluctuations in the rubber compound, ensuring the consistency of density in each molded part.

[0131] See attached document Figure 4 In step S400, a sub-step of orthogonal analysis of rheological state and adaptive compensation of process parameters is further included. This step is executed by the compensation unit in decision module 143. This step is based on the physical principles of polymer processing rheology: the change in flow resistance of the rubber compound during molding is the result of the combined effects of "physical thermal denaturation" (temperature increase leading to viscosity decrease) and "chemical crosslinking" (vulcanization reaction leading to viscosity increase). Traditional single pressure feedback control cannot distinguish between these two mechanisms and is prone to misjudgment leading to incorrect adjustment direction. For example, the high resistance caused by scorching may be misjudged as the high resistance of cold material caused by excessively low mold temperature. This embodiment introduces the in-situ vulcanization rate index (chemical dimension) and stress relaxation rate (physical viscoelastic dimension) to construct a two-dimensional orthogonal coordinate system, realizing the decoupled analysis of the micro-state of the rubber compound. The specific implementation process includes:

[0132] S430, Perform orthogonal analysis of the rheological state. The compensation unit is based on the in-situ sulfidation rate index obtained in step S300. With stress relaxation rate A two-dimensional rheological state space is constructed. In this state space, the horizontal axis represents the chemical kinetic dimension. The vertical axis reflects the rate of material crosslinking reactions; the horizontal axis characterizes the physical viscoelastic dimension. It reflects the current microscopic molecular chain mobility of the material.

[0133] In this embodiment, the compensation unit calculates the coordinate points obtained in the current cycle. The data is mapped to this two-dimensional space and compared with a preset standard process window. The standard process window is determined by collecting production data from qualified products of no less than a preset sample size (e.g., 50 molds) and calculating its... and arithmetic mean and standard deviation Define the window range as .

[0134] Using this orthogonal analysis method, the compensation unit can distinguish between two typical abnormal states:

[0135] The first state is "scorched / premature ripening state", which is characterized by: Significantly higher than ,at the same time Significantly lower than This indicates that the chemical reaction rate is too fast, and the material's elastic characteristics become dominant too early, resulting in a loss of stress relaxation ability and early cross-linking of the rubber compound during the filling stage.

[0136] The second state is "under-sulfurized / insufficient mold temperature state", which is characterized by: Significantly lower than ,at the same time Significantly higher than This indicates that the chemical reaction rate is slow, and the material remains in a highly viscous fluid state, lacking elastic resilience, and has not established a sufficient cross-linked network within the predetermined time.

[0137] S440, execute adaptive compensation for process parameters. Based on the determination results of the orthogonal analysis above, the compensation unit calls differentiated parameter correction models for different abnormal modes, generating process correction instructions for the next production cycle.

[0138] In response to the "scorching / premature ripening" condition, the system determines that the current thermal history is excessive. The compensation unit prioritizes adjusting the heating temperature. (For example, the barrel temperature of an injection molding machine) The preheating temperature of the press (or other equipment) is negatively corrected to suppress the early reactivity of the rubber compound before it enters the mold. Correction amount The calculation formula is as follows:

[0139] ;

[0140] In the formula, The step size for adjusting the heating temperature, in degrees Celsius (°C). The first proportional gain coefficient has a value ranging from 0.5 to 1.5. Its specific value is determined based on the step response test of the temperature control system. The more sensitive the heating system is, the smaller the value should be to avoid overshoot. This represents the currently measured in-situ sulfidation rate index; This is the target value at the center of the standard process window. In this embodiment, if the scorching characteristics cannot be eliminated even after the temperature adjustment reaches the lower limit of the equipment, the compensation unit will further shorten the holding time after mold closing or reduce the injection speed / mold closing speed to reduce the impact of shear heat generation on the scorching of the rubber compound.

[0141] In response to the "under-curing / insufficient mold temperature" condition, the system determines that the current crosslinking energy is insufficient. The compensation unit prioritizes adjusting the curing time. Extend the correction period to ensure a full response. Correction amount. The calculation formula is as follows:

[0142] ;

[0143] In the formula, This is the adjustment step size for the vulcanization time, in seconds (s). The second proportional gain coefficient ranges from 2.0 to 5.0. This coefficient is inversely proportional to the slope of the plateau period of the rubber vulcanization curve. The smaller the slope (i.e., the slower the reaction), the larger the value of this coefficient. This represents the currently measured stress relaxation rate; This is the center target value of the standard process window. In this embodiment, if the time adjustment amount... If the current cycle time exceeds 10%, the compensation unit will simultaneously adjust the mold temperature. Perform positive corrections to improve the overall reaction rate.

[0144] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A control method for an automated production line of sealing rings, characterized in that, Includes the following steps: Torque and displacement data during the exhaust stroke are collected under no-load conditions to construct a reference resistance curve incorporating mechanical friction and hydraulic damping. The exhaust stroke path is divided into multiple micro-position intervals, and the collected time-series data is mapped to the corresponding micro-position intervals. The servo press is controlled to continuously execute multiple no-load cycles, and the arithmetic mean of the torque within each micro-position interval is calculated. A moving average filtering algorithm is used to smooth the arithmetic mean, generating the reference resistance curve that varies with position. The equipment temperature or production cycle is monitored in real time. When the monitored temperature change exceeds a preset temperature drift threshold, linear compensation is performed on the reference resistance curve based on viscosity-temperature characteristics. The servo press is controlled to perform multiple exhaust actions. During the closing process of each exhaust action, the speed is switched from a fast approach speed to a micro-speed test speed, and the position is locked after the last exhaust action is closed. Based on the torque data under the micro-speed test and the torque decay data under the position lock state, the net rheological torque is calculated in combination with the reference resistance curve, and the contact displacement drift reflecting the filling state of the rubber compound, the in-situ vulcanization rate index reflecting the curing rate, and the stress relaxation rate reflecting the viscoelasticity of the material are calculated; wherein, (1) the total load torque collected in real time is subtracted from the value of the reference resistance curve at the corresponding position to obtain the net rheological torque; the first spatial derivative of the net rheological torque with respect to the displacement is calculated to obtain the torque gradient, and the position where the torque gradient exceeds the preset gradient judgment threshold is identified as the contact position; the contact position of the first venting action and the contact position of the last venting action are identified respectively, and the difference between the contact position of the first venting action and the contact position of the last venting action is calculated to obtain the contact displacement drift; (2) in the net flow Select the linear compression interval after the contact position on the variable torque curve; calculate the torque displacement slope of the first and last exhaust actions in the linear compression interval respectively to obtain the corresponding transient stiffness; calculate the difference between the transient stiffness of the last exhaust action and the transient stiffness of the first exhaust action, and divide the difference by the time interval between the first and last exhaust actions to obtain the in-situ vulcanization rate index; (3) In the position locking state, switch the servo control mode to position closed-loop control to resist the rebound force of the rubber material and keep the mold position constant; collect the initial peak torque at the start of the position locking and the termination residual torque after the preset locking time; calculate the difference between the initial peak torque and the termination residual torque, and divide the difference by the initial peak torque to obtain the stress relaxation rate; The filling stability is determined based on the contact displacement drift, the rheological state of the rubber compound is determined based on the combination of the in-situ vulcanization rate index and the stress relaxation rate, and a process correction instruction is generated based on the filling stability and the rheological state of the rubber compound.

2. The control method for an automated production line of sealing rings according to claim 1, characterized in that, In the process of controlling the servo compressor to perform multiple exhaust actions, the logic regarding speed switching is as follows: Define the mold closing direction as the direction in which the position coordinate value increases; Determine the speed switching position, which is the mold fully closed position or the estimated material contact position minus the preset safety buffer distance; The servo press is controlled to run at the rapid approach speed to the speed switching position, and then decelerates in a step to the micro-speed test speed; The setting of the safety buffer distance must ensure that the braking distance required for the servo press to decelerate from the rapid approach speed to the micro-speed test speed is less than the safety buffer distance, so as to ensure that the mold has entered the micro-speed state before contacting the rubber material.

3. The control method for an automated production line of sealing rings according to claim 2, characterized in that, The steps for controlling the servo compressor to perform multiple exhaust actions also include: After the speed command is switched, a preset steady-state setup delay is executed, which is greater than the step response adjustment time of the servo system. Data acquisition is initiated after the steady-state establishment delay ends to ensure that the angular acceleration of the servo motor approaches zero at the time of acquisition, thereby eliminating the interference of inertial torque on the rheological resistance measurement.

4. The control method for an automated production line of sealing rings according to claim 1, characterized in that, The steps for determining filling stability and identifying foreign object risks based on the contact displacement drift include: The absolute value of the contact displacement drift is compared with a preset stability threshold. If the absolute value is greater than the stability threshold, it is determined that the filling is not up to standard, and the number of venting actions is increased until the absolute value is less than or equal to the stability threshold. Simultaneously monitor the transient stiffness and the stress relaxation rate. If the transient stiffness is higher than the preset upper limit threshold for stiffness safety and the stress relaxation rate is lower than the preset lower limit threshold for relaxation rate, it is determined that there is a hard foreign object and an emergency stop protection command is triggered.

5. The control method for an automated production line of sealing rings according to claim 1, characterized in that, The steps for generating process correction instructions include: A two-dimensional orthogonal state space is constructed with the in-situ sulfurization rate index as the chemical kinetic dimension and the stress relaxation rate as the physical viscoelastic dimension. If the current state point shows that the in-situ vulcanization rate index is higher than the preset upper limit of the in-situ vulcanization rate index and the stress relaxation rate is lower than the preset lower limit of the stress relaxation rate, it is determined to be a scorching state, and a correction command to reduce the heating temperature is generated. If the current state point shows that the in-situ vulcanization rate index is lower than the preset lower limit of the in-situ vulcanization rate index and the stress relaxation rate is higher than the preset upper limit of the stress relaxation rate, it is determined to be an under-vulcanization state, and a correction command to extend the vulcanization time or increase the mold temperature is generated.

6. A control system for an automated production line of sealing rings, applied to the method described in any one of claims 1-5, characterized in that, include: The data acquisition module is configured to acquire torque and displacement data during the exhaust stroke when the equipment is unloaded, and to construct a reference resistance curve that includes mechanical friction and hydraulic damping. A servo unit is configured to drive a mold assembly to execute a micro-speed steady-state venting process sequence in response to control commands. The micro-speed steady-state venting process sequence includes switching from a rapid approach speed to a micro-speed test speed during the closing process and maintaining a position-locked state at the end of the closing process. The decoupling module is configured to calculate the net rheological torque based on the torque data at the micro-speed test and the torque attenuation data under the position lock-up state, combined with the reference resistance curve, and extract the contact displacement drift, in-situ vulcanization rate index and stress relaxation rate. The decision module is configured to determine the filling stability based on the contact displacement drift, determine the rheological state of the rubber compound based on the combination of the in-situ vulcanization rate index and the stress relaxation rate, and generate process correction instructions based on the filling stability and the rheological state of the rubber compound.

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