Synchronous control system for multiple servo motors of main machine of circular weaving machine

Abstract

The invention relates to a synchronous control system for multiple servo motors of a main machine of a circular weaving machine, which belongs to the technical field of industrial automation control and comprises a state characterization unit used for acquiring multi-scale state information for characterizing the running state of the system in real time; the risk assessment unit is used for calculating a comprehensive instability index of the system in real time according to the multi-scale state information and preset physical parameters of the system; and the control strategy switching unit is used for comparing the comprehensive instability index of the system with a preset first threshold value and a preset second threshold value, and selecting and executing a corresponding control strategy from a reference control strategy, an active avoidance strategy and an emergency intervention strategy in response to a comparison result. According to the invention, the state characterization unit, the risk assessment unit and the control strategy switching unit are arranged, so that the management of the system instability risk is realized.

Description

Technical Field

[0001] This invention relates to the field of industrial automation control, specifically to a synchronous control system for multiple servo motors of a circular loom. Background Technology

[0002] In circular looms employing multiple servo motors in direct drive, especially when weaving asymmetric fabrics, the system faces a complex instability problem caused by the coupling of multiple factors. Traditional control methods, such as proportional-integral-derivative (PI-DI) control or active disturbance rejection (ADRC), are typically based on decoupled linear system models and assumptions of linear compensation for disturbances; however, these control models fail under specific operating conditions. The root of the problem lies in a deep nonlinear cascade amplification effect. First, minute differences in the pulse-width modulation (PWM) carrier frequencies of the drivers generate low-frequency beat electromagnetic interference (EMI), which contaminates the encoder's position feedback signal. Second, mechanical non-ideal factors in the transmission chain, such as non-uniform tooth flank backlash in the spline shaft due to manufacturing and wear, produce microscopic mechanical shocks and phase jitter at specific rotation angles. When the loom operates at high speed, the servo system performs high-frequency torque adjustments to compensate for these pseudo-position errors caused by the combined electromagnetic interference and mechanical shocks. The adjustment frequency or harmonics of this adjustment may match a high-order inherent torsional vibration mode of a key structure such as the main loom's ring beam; this matching triggers a frequency-locked-energy-pumping positive feedback mechanism. At this point, the servo control system not only fails to suppress vibration but also continuously pumps electromagnetic energy into the mechanical structure, leading to uncontrolled macroscopic torsional vibration and a sharp amplification of amplitude. This phenomenon has a significant counterintuitive characteristic: attempting to suppress vibration by increasing servo gain and stiffness, as is the conventional approach, accelerates the frequency locking process, causing the system to enter uncontrolled oscillation more quickly. This ultimately results in a surge in fabric defect rates and frequent shutdowns due to misjudgments in the protection strategy. Existing technologies have failed to provide an effective solution for predicting and avoiding this nonlinear resonant instability.

[0003] The information disclosed in the background section above is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a synchronous control system for multiple servo motors of a circular loom main unit to solve the problems mentioned in the background art.

[0005] The technical solution of the present invention includes: The state representation unit is used to acquire multi-scale state information that represents the operating state of the system in real time. The risk assessment unit is used to calculate the comprehensive instability index of the system in real time based on multi-scale state information and preset system physical parameters; The control strategy switching unit is used to compare the system's overall instability index with a preset first threshold and a second threshold, and in response to the comparison result, select and execute the corresponding control strategy from the baseline control strategy, the active avoidance strategy, and the emergency intervention strategy.

[0006] Preferably, the multi-scale state information includes: the rate of change of macroscopic torsional vibration angular frequency, the servo current impact response time constant, and the normalized microscopic acoustic emission energy envelope integral value.

[0007] Preferably, the state representation unit is specifically used for: By deploying vibration sensors on the host-driven ring beam and combining them with signal processing methods, the rate of change of macroscopic torsional vibration angular frequency is obtained. By monitoring the DC bus current of each servo driver, the current surge caused by load mutation is identified and calculated, thereby obtaining the servo current surge response time constant. High-frequency stress wave signals are collected by acoustic emission sensors arranged in the mechanical contact area to obtain the normalized microscopic acoustic emission energy envelope integral value.

[0008] Preferably, the risk assessment unit is specifically used to: calculate the system's comprehensive instability index by combining multi-scale state information, a preset loom spindle reference working angular velocity, a set of beat frequency intervals, and the high-order torsional resonance angular frequency of the main machine structure.

[0009] Preferably, the execution logic of the control strategy switching unit is defined as follows: When the overall system instability index is less than or equal to the first threshold, the baseline control strategy is executed. When the overall system instability index is greater than the first threshold and less than the second threshold, an active avoidance strategy is executed. When the overall system instability index is greater than or equal to the second threshold, an emergency intervention strategy is implemented.

[0010] Preferably, the active avoidance strategy includes performing dynamic optimization of the pulse width modulation carrier frequency and superimposing adaptive feedforward damping torque into the servo torque command.

[0011] Preferably, the execution process of the pulse width modulation carrier frequency dynamic optimization is as follows: Based on the system's beat angle frequency set and structural resonant frequency, a risk cost function is constructed. The risk cost function is solved by numerical optimization algorithm to obtain the set of optimal carrier angular frequency offsets that minimize the function value; Apply the optimal carrier angular frequency offset set to each servo driver.

[0012] Preferably, the adaptive feedforward damping torque is generated in the following manner: Obtain the macroscopic torsional vibration angular velocity obtained after processing the vibration sensor signal; Based on the system's overall instability index, the first threshold, the second threshold, and the preset damping gain coefficient, a dynamic damping coefficient is generated; The adaptive feedforward damping torque is obtained by multiplying the dynamic damping coefficient by the macroscopic torsional vibration angular velocity.

[0013] Preferably, the emergency intervention strategy includes: forcibly smoothing the output torque of all servo motors and guiding the system to slow down in a controlled manner to a preset absolute safe speed range.

[0014] This invention provides an improved synchronous control system for multiple servo motors on a circular loom, which has the following improvements and advantages compared to the prior art: 1. This invention constructs a closed-loop control architecture that covers the entire process from pre-prediction to proactive avoidance and then to emergency response, changing the limitations of the passive response of traditional control methods. This invention achieves the management of system instability risk by establishing a state representation unit, a risk assessment unit, and a control strategy switching unit. 2. This invention provides a forward-looking judgment on the rate of change of macroscopic torsional vibration angular frequency obtained from vibration sensor signals, thus providing a predictive assessment of the rate of macroscopic vibration deterioration in the system. Secondly, by monitoring the impact response time constant obtained from the DC bus current of the servo driver, the response delay of the electronic control system to external load mutations is quantified, revealing the inherent sensitivity of the system. Thirdly, by obtaining the normalized microscopic acoustic emission energy envelope integral from the acoustic emission sensor, the microscopic mechanical impact energy caused by factors such as tooth flank clearance is captured, and the excitation factors that induce instability are monitored. This multi-dimensional, cross-scale information fusion provides a comprehensive and in-depth data foundation for accurately assessing system stability, far exceeding the control mode based on a single feedback quantity in existing technologies. 3. The risk assessment unit of this invention can transform complex state information into a single index with clear physical meaning, namely the system comprehensive instability index. This unit not only assesses the inherent spontaneous instability trend of the system, but also quantifies the risk of coupling between all potential electromagnetic beat excitation frequencies and their harmonics and the inherent resonant frequency of the host structure through a dedicated phenomenological model. This model can accurately predict the situation where the resonance risk increases sharply when any beat frequency approaches an integer multiple of the structural resonant frequency. By calculating a dimensionless comprehensive instability index, the system can accurately and uniformly quantify the instability risk, providing a reliable basis for subsequent decision-making and switching. 4. This invention achieves dynamic adjustment of the control target. When the instability index is below the first threshold, the system executes a baseline control strategy to pursue the highest production efficiency and fabric quality. When the index is between the first and second thresholds, the system enters an active avoidance mode, at which point the control target switches from pursuing performance to avoiding risks. In this mode, the system collaboratively executes two core actions: First, it performs dynamic optimization of the pulse width modulation carrier frequency, solving and applying a set of optimal frequency offsets through numerical optimization algorithms to push the beat excitation frequency away from the dangerous resonance region, eliminating the excitation conditions for resonance at the root. Second, it generates an adaptive feedforward damping torque, the magnitude of which is proportional to the instability risk index, providing the system with precise additional damping that perfectly matches the risk level, effectively suppressing vibration. The combination of these two measures can efficiently resolve potential instability risks without interrupting production, solving the counterintuitive problem in existing technologies where increasing stiffness exacerbates oscillations. Attached Figure Description

[0015] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a flowchart of a synchronous control system for multiple servo motors of a circular loom main unit according to the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0017] Example 1 Please see Figure 1 This invention provides a synchronous control system for multiple servo motors on a circular loom, comprising: The state representation unit is used to acquire multi-scale state information that represents the operating state of the system in real time. The risk assessment unit is used to calculate the comprehensive instability index of the system in real time based on multi-scale state information and preset system physical parameters; The control strategy switching unit is used to compare the system's overall instability index with a preset first threshold and a second threshold, and in response to the comparison result, select and execute the corresponding control strategy from the baseline control strategy, the active avoidance strategy, and the emergency intervention strategy. This embodiment proposes a synchronous control system for multiple servo motors of a circular loom main unit; This system is designed to predict and avoid complex instability problems caused by multiple coupled factors, especially when weaving asymmetric fabrics, on circular looms. Traditional control methods, such as PID or ADRC, are based on decoupled linear system models and fail when faced with the nonlinear cascade amplification effect caused by the combined effects of driver PWM carrier frequency difference and non-ideal mechanical transmission factors. This effect manifests as small electromagnetic interferences and mechanical shocks, under high-speed operation, being adjusted at high frequencies by the servo system. The harmonics may match the inherent torsional vibration modes of the main machine's key structure, triggering a frequency-locked-energy-pumping positive feedback, leading to macroscopic torsional vibration runaway. This system solves the counterintuitive problem that increasing stiffness exacerbates oscillations by proactively predicting and avoiding risks. This system includes a state representation unit, a risk assessment unit, and a control strategy switching unit; The purpose of the state characterization unit is to capture the physical state of the system in real time and at multiple scales, reflecting the entire cascade effect chain from microscopic disturbances to macroscopic vibrations. In this embodiment, the unit integrates multiple sensors and uses specific signal processing methods to obtain a set of state information vectors that can quantify the current operating state of the system. The risk assessment unit aims to integrate multi-scale state information provided by the state characterization unit with pre-identified system physical parameters, thereby calculating a scalar index that can accurately quantify the risk of system resonance instability in real time. In this embodiment, the unit receives a state information vector and calculates the comprehensive instability index of the system based on a phenomenological model that integrates the system dynamic stability criterion and the resonance linear function. The control strategy switching unit aims to apply the optimal control strategy in different operating ranges based on the instability index calculated by the risk assessment unit, so as to achieve a smooth transition from stable operation to active avoidance and then to emergency intervention. In this embodiment, the unit compares the real-time calculated system comprehensive instability index with two preset thresholds, and selects one of the three predefined modes—baseline control strategy, active avoidance strategy, and emergency intervention strategy—based on the comparison result and instructs the servo system to execute it. The system proposed in this embodiment, by constructing a functional closed loop of state representation, risk assessment and strategy switching, can achieve early prediction and proactive avoidance of complex instability phenomena. Without sacrificing normal production efficiency, it can greatly reduce the fabric defect rate and equipment downtime caused by resonance instability, thus ensuring the stability of the weaving process and product quality.

[0018] Multi-scale state information includes: macroscopic torsional vibration angular frequency change rate, servo current impact response time constant, and normalized microscopic acoustic emission energy envelope integral value; The state representation unit is specifically used for: By deploying vibration sensors on the host-driven ring beam and combining them with signal processing methods, the rate of change of macroscopic torsional vibration angular frequency is obtained. By monitoring the DC bus current of each servo driver, the current surge caused by load mutation is identified and calculated, thereby obtaining the servo current surge response time constant. High-frequency stress wave signals were collected by acoustic emission sensors arranged in the mechanical contact area to obtain the normalized microscopic acoustic emission energy envelope integral value. In this embodiment, multi-scale state information is specified, and its acquisition method is also clarified; The state representation unit in this embodiment is responsible for acquiring three key, hierarchical state information: Macroscopic torsional vibration angular frequency change rate Its function is to characterize the rate of deterioration of macroscopic vibrations and is a core precursor indicator that predicts the instability of the system. This refers to the rate of change of the angular frequency corresponding to the peak value of the torsional vibration main spectrum of the host-driven ring beam, measured in rad / s². In this embodiment, vibration sensors, such as accelerometers, are deployed on the host-driven ring beam. The state characterization unit performs continuous short-time Fourier transform or similar time-frequency analysis processing on the collected vibration signals to track the drift of the peak value of the main vibration frequency in real time, and obtains the rate of change by performing time difference calculation on the angular frequency. ; Servo current impulse response time constant Its function is to quantify the electronic control response delay of the system to sudden changes in external load, such as changes in yarn tension or cam crossing a threshold; This refers to the time required for the DC bus current of each servo drive to recover from its peak value to its steady-state value after being subjected to a load surge, measured in seconds. In this embodiment, the state characterization unit continuously monitors the DC bus current of each servo drive, uses edge detection or threshold comparison algorithms to identify current surge events caused by load surges, and calculates the time required for each surge to decay from its peak value to, for example, 1 / e times its peak value, as... The instantaneous value; Normalized microscopic acoustic emission energy envelope integral Its function is to capture the micro-mechanical impact energy caused by non-ideal mechanical factors, such as tooth backlash. This refers to the dimensionless value obtained by integrating and normalizing the energy envelope of high-frequency stress waves within a specific time window; in this embodiment, acoustic emission sensors are arranged in key mechanical contact areas, such as the contact surface between the transmission spline or the knitting needle cam and the swing arm. The principle for selecting the critical mechanical contact area is that the mechanical impact event in this area should be the main source of triggering or reflecting the early microscopic non-ideal behavior of the loom instability, and the sensor should have a high signal-to-noise ratio at this location; in addition to the contact surface between the transmission spline or the needle cam and the swing arm, other preferred locations may include the meshing area of ​​the main drive gear or the impact point of the shuttle box reversing mechanism. The state characterization unit acquires high-frequency stress wave signals, calculates their energy envelope using methods such as Hilbert transform, integrates the envelope over a specific time period, and normalizes it using statistical characteristics of historical operating data, such as the mean or maximum value, to obtain... ; In this way, the state representation unit represents the macroscopic vibration trend. Response characteristics of electronic control system and microscopic mechanical impact sources The fusion of information from these three different physical levels provides a comprehensive and in-depth data foundation for subsequent risk assessment, thereby significantly improving the accuracy of instability prediction.

[0019] The risk assessment unit is specifically used to: combine multi-scale state information, preset loom spindle reference working angular velocity, beat frequency set, and high-order torsional resonance angular frequency of the main machine structure to calculate the system's comprehensive instability index; In this embodiment, the calculation method of the risk assessment unit is explained; The core function of this risk assessment unit is to calculate the dimensionless system comprehensive instability index. This index aims to integrate the inherent instability trend with the coupling risk of external incentives to comprehensively assess the overall stability of the system. The calculation is based on a specialized phenomenological model, and the mathematical expression is as follows: ; in, The System Comprehensive Instability Index is a dimensionless scalar calculated in real time. It is derived from the output of this risk assessment unit and serves as the sole basis for subsequent control strategy switching. The rate of change of the angular frequency of the peak value of the main spectrum of macroscopic torsional vibration, in rad / s², is provided by the aforementioned state characterization unit and directly reflects the rate of vibration deterioration. Servo current impulse response time constant, in seconds, is provided by the aforementioned state characterization unit and reflects the electronic control response characteristics of the system. The reference working angular velocity of the loom spindle, in rad / s. This constant is a preset reference value based on the loom design and typical operating conditions, used to normalize the first term to ensure it is dimensionless. In system implementation, it is necessary to... The value is used for protective judgment, when When it is zero or close to zero, the system's overall instability index The first term should be set to zero to prevent calculation errors; The normalized microscopic acoustic emission energy envelope integral is dimensionless and is provided by the aforementioned state characterization unit, reflecting the severity of the microscopic mechanical impact. The set of beat frequency intervals is the set of absolute differences between all pairwise PWM carrier angular frequencies of all servo drivers in the system; if the first... The carrier angular frequency of the driver is Then the set Calculated from the current carrier frequency of each driver; this set represents potential electromagnetic excitation frequency sources; Let be the carrier angular frequency of the k-th servo driver; : Traversing a collection Each beat angle frequency in the table is expressed in rad / s. The high-order torsional resonance angular frequency closely related to instability in the main structure, in rad / s; this parameter is identified in advance by experimental methods such as offline frequency sweep excitation or hammer impact modal testing of the loom and stored as a preset parameter in the system; : Harmonic order, a positive integer, representing the possibility of resonance coupling between each order of harmonics at the beat frequency and the structure; Frequency lock bandwidth factor, in rad / s, is a value that is preset based on the modal damping ratio of key components such as the main unit's ring beam. Physically, it defines how close the excitation frequency and the resonant frequency are to produce a significant resonance effect. Two dimensionless weighting coefficients; their proportional relationship is determined by analyzing historical operating data or conducting offline calibration experiments, and stored as preset parameters to balance the relative importance of the inherent instability trend and the external stimulus coupling risk in the overall risk assessment. N: Upper limit of harmonic order n; exp: Exponential function; In some implementations, the system can pre-identify and store a set containing multiple key resonant angular frequencies. At this point, the risk assessment unit will traverse all frequencies in this set to address instability issues caused by different structural modes under different operating conditions; To enable those skilled in the art to determine the above parameters without excessive experimentation, this embodiment provides an offline calibration experimental method, the steps of which are as follows: Step 1: Modal testing and initial understanding of parameters.

[0020] Modal testing of the circular loom main unit using offline frequency sweep excitation or hammer impact method not only obtains the high-order torsional resonant angular frequency closely related to instability, but also... The damping ratio of this mode was also measured. Frequency-locked bandwidth factor The damping ratio can be set based on this, and a typical setting principle is to correlate it with the half-power bandwidth of this mode. For example, it can be set to... ;in, The damping ratio of a specific mode as determined in modal testing; Step 2: Controlled instability induction and data acquisition.

[0021] A series of controlled experiments were conducted under no-load or light-load conditions on the loom to determine the operating angular velocity of the main machine. Within its design range, adjustments are made in stages. At each speed level, the pulse width modulation carrier frequency of each servo driver is manually set, resulting in a set of beat angle frequencies. a certain frequency low-order harmonics Approaching the known structural resonant frequency This actively induces resonance of varying degrees; during this process, three core data points output by the system's state characterization unit are simultaneously and frequently acquired: the rate of change of macroscopic torsional vibration angular frequency. Servo current impulse response time constant and the microscopic acoustic emission energy envelope integral Simultaneously, the vibration amplitude of the main unit driving the ring beam was recorded using an independent vibration analyzer. As an objective and quantitative indicator of the degree of system instability; Step 3: Data-driven threshold and coefficient calibration.

[0022] Perform statistical analysis and optimization calculations using the dataset collected in the previous step: Calibration threshold and The collected vibration amplitude Divided into three levels: safe, such as ,warn, and danger, For each group of collected data The data is used to calculate an unweighted risk index. Statistical methods, such as plotting receiver operating characteristic curves, are employed to identify the two optimal threshold points that distinguish these three levels; these are designated as the first threshold. Second threshold The optimization goal is to minimize the false alarm rate and false positive rate while ensuring a high detection rate and true positive rate. Calibration weighting coefficients and The calibration problem is transformed into an optimization problem. An objective function is defined, for example, to make the overall system instability index for all experimental data points equal. Its corresponding objective vibration amplitude Maximizing the Pearson correlation coefficient, i.e., solving for: ; in, : Refers to finding the parameters that maximize the objective function. and The value of corr: Pearson correlation coefficient function; S: System overall instability index; In the instability-induced experiment, the vibration amplitude of the host-driven ring beam, recorded by an independent vibration analyzer, is used as a quantitative indicator of the system's instability. in The calculation formula is: ; The optimal weighting coefficients can be determined by performing nonlinear fitting on a large number of collected data points or by using optimization algorithms, such as particle swarm optimization. and ; Step 4: Tuning the damping gain coefficient.

[0023] In the already calibrated and Based on this, a verification experiment of the active avoidance strategy was conducted; the system was running at Under the operating conditions, gradually increase the damping gain coefficient. The value of is determined, and the effect of vibration suppression is observed. A value is selected that can effectively suppress the vibration amplitude in the shortest time without causing system overshoot or control command saturation. The value is used as the final preset parameter; Through the above steps, all key preset parameters can be systematically and reproducibly determined, thereby ensuring that the present invention can be reliably implemented by those skilled in the art. The first term of this formula The first term quantifies the system's inherent, spontaneous instability tendency; the second term, through a summation of Gaussian functions, quantifies all potential electromagnetic beat excitation frequencies. and its harmonics With the structure's inherent resonant frequency The risk of coupling occurs; when any beat frequency approaches an integer multiple of the resonant frequency, the corresponding exponential term approaches 1, thus significantly increasing the risk. value; Through the calculations of this model, the risk assessment unit can quantify multiple seemingly unrelated physical quantities into a unified instability index with clear physical meaning. This provides a reliable basis for the system to achieve precise and timely switching of control strategies.

[0024] Example 2 The execution logic of the control strategy switching unit is defined as follows: When the overall system instability index is less than or equal to the first threshold, the baseline control strategy is executed. When the overall system instability index is greater than the first threshold and less than the second threshold, an active avoidance strategy is executed. When the overall system instability index is greater than or equal to the second threshold, an emergency intervention strategy is implemented. In this embodiment, the execution logic of the control strategy switching unit is clearly defined; The operation of this control strategy switching unit is based on the real-time calculated system comprehensive instability index. The system employs a hierarchical judgment mechanism; internally, it incorporates a decision rule based on two pre-defined dimensionless thresholds, namely the first threshold... Second threshold ,satisfy The system's operating state is divided into three different control regions, and corresponding control strategies are executed. The specific values ​​of these two thresholds are determined based on statistical analysis of a large amount of historical operating data, or through controlled instability-induced experiments conducted on the loom. The principle for setting these thresholds is to balance the efficiency and safety of the system operation, and to ensure sufficient early warning lead time while avoiding false alarms. The execution logic is defined as follows: when At this time, the baseline control strategy is executed; within this range, the system is judged to be in a stable operating area with extremely low risk of instability; the goal of the control system is to maximize efficiency, so an optimized, high-performance synchronous control algorithm is adopted, such as a feedforward control strategy with high gain and fast response, to ensure precise synchronization between servo motors and the highest production quality of the fabric. when At this time, an active avoidance strategy is implemented; in this range, the system is judged to have entered a potential instability risk zone, showing obvious signs of instability, but has not yet reached the critical point of loss of control; the control objective is switched from pursuing performance to actively avoiding risks; the system will initiate a series of intervention measures aimed at breaking the frequency lock-energy pumping positive feedback loop, and pull the system back to the stable zone without interrupting production; when When this occurs, an emergency intervention strategy is implemented; within this range, the system is judged to be about to or has already experienced resonant instability, posing a serious threat to equipment safety and product quality; the control objective immediately switches to ensuring safety at all costs; the system will execute a set of the most conservative intervention actions, aimed at quickly cutting off the energy positive feedback loop and bringing the system into a known state of absolute safety; Through this basis The index's hierarchical decision-making logic and control strategy switching unit enable dynamic and intelligent adjustment of control objectives, allowing the system to take the most appropriate countermeasures under different risk levels. This achieves closed-loop management of the entire process from prediction and avoidance to emergency response for complex instability problems.

[0025] Example 3 The active avoidance strategy includes performing dynamic optimization of the pulse width modulation carrier frequency and superimposing adaptive feedforward damping torque into the servo torque command; The execution process of dynamic optimization of pulse width modulation carrier frequency is as follows: Based on the system's beat angle frequency set and structural resonant frequency, a risk cost function is constructed. The risk cost function is solved by numerical optimization algorithm to obtain the set of optimal carrier angular frequency offsets that minimize the function value; Apply the optimal carrier angular frequency offset set to each servo driver; The adaptive feedforward damping torque is generated as follows: Obtain the macroscopic torsional vibration angular velocity obtained after processing the vibration sensor signal; Based on the system's overall instability index, the first threshold, the second threshold, and the preset damping gain coefficient, a dynamic damping coefficient is generated; Multiplying the dynamic damping coefficient by the macroscopic torsional vibration angular velocity yields the adaptive feedforward damping torque; Based on Example 2, the specific implementation method of the active avoidance strategy is further defined; When the system's overall instability index satisfy At this time, the system enters the active avoidance zone and performs two core control actions in coordination: one is dynamic optimization of the pulse width modulation carrier frequency, and the other is superimposing an adaptive feedforward damping torque into the servo torque command. The core purpose of these two measures is to break the necessary conditions for resonance. The former avoids resonance by eliminating the excitation source, and the latter suppresses vibration by increasing the system damping. The execution process of dynamic optimization of pulse width modulation carrier frequency is as follows: This process aims to solve for a set of optimal carrier angular frequency offsets. This is applied to each servo driver, thereby causing the new set of beat frequencies to move away from the structural resonant frequency, in order to minimize the resonance risk of the system. Building and Risk cost function with the same form as the resonant term in the exponent : ; in, Is applying offset The new difference in beat frequency, It is a new set of beat angle frequencies; the system can be solved using a standard numerical optimization algorithm, such as gradient descent or particle swarm optimization. The set of offsets whose function values ​​are minimized ; For risk cost function; : A set of optimal carrier angular frequency offsets applied to each servo driver; n: harmonic order, a positive integer; N: upper limit of harmonic order n; exp: exponential function; : Structural resonant frequency; σ: Frequency-locked bandwidth factor; This solution process also needs to satisfy constraints. ,in This is the maximum allowable frequency offset preset to ensure the normal operation of the driver; : The carrier angular frequency offset applied to the i-th servo driver; Finally, the optimal offset set obtained is applied to each servo driver; This process can effectively push the electromagnetic excitation frequency away from the dangerous resonance region; The adaptive feedforward damping torque is generated as follows: This process obtains the real-time macroscopic torsional vibration angular velocity by processing vibration sensor signals. The unit is rad / s, and this variable directly reflects the current instantaneous vibration velocity of the structure; the calculation model is based on the system's comprehensive instability index. First threshold Second threshold and a preset damping gain coefficient obtained through experimental tuning The unit is N·m·s / rad. The adaptive feedforward damping torque is calculated using the following formula. : ; in, : Adaptive feedforward damping torque, in N·m; γ: Preset damping gain coefficient obtained through experimental tuning, in N·m·s / rad; S: Real-time system integrated instability index; First threshold, a preset dimensionless threshold; The second threshold is a preset dimensionless threshold that satisfies... ; Real-time macroscopic torsional vibration angular velocity obtained by processing vibration sensor signals, in rad / s; This formula embodies an adaptively improved classical viscous damping control law. The dynamic damping coefficient is determined by... The term is given by a normalization factor. Its value varies between 0 and 1 to adjust the base damping gain in real time. This allows the effective damping applied to the system to be determined according to the risk index. The level is 0, when The time has come ,when Approaching Smooth adjustment between time intervals; Emergency intervention strategies include: forcibly smoothing the output torque of all servo motors and guiding the system to decelerate in a controlled manner to a preset absolute safe speed range; In this embodiment, the implementation method of the emergency intervention strategy is further clarified; When the system's overall instability index Greater than or equal to the second threshold At this time, the system enters the emergency intervention zone; at this point, the highest priority of the control system is to ensure the absolute safety of the equipment and products, preventing mechanical damage or numerous fabric defects caused by severe vibration; this strategy includes two coordinated actions: The system will forcibly smooth the output torque of all servo motors; this can be achieved by applying a low-pass filter to the torque command path or by forcibly limiting the rate of change of torque. In this embodiment, the preferred smoothing method is to apply a second-order Butterworth low-pass filter with a cutoff frequency of It can be set to a frequency much lower than the structural resonant frequency of the host, for example, it can be taken as... This is to effectively filter out high-frequency disturbances while retaining the necessary low-frequency torque response; among which, The structural resonant frequency of the host computer; The purpose of this measure is to immediately cut off the servo system's excessive response to high-frequency pseudo-position errors, which is a key link in the energy pumping into the mechanical structure; by smoothing the output torque, even if vibration cannot be completely eliminated, the further expansion of the vibration amplitude can be effectively prevented. The system will guide the system to decelerate in a controlled manner to a preset absolute safe speed range. The safe speed range is set based on the fact that known resonance instability usually occurs in a specific high-speed range. The system will generate a smooth deceleration curve and instruct all servo motors to reduce their speed synchronously and smoothly until they enter a low-speed operating range that has been determined through previous experiments or experience and will not cause any resonance instability. A gentle deceleration curve is preferably a trapezoidal or S-shaped speed curve to avoid the deceleration process itself introducing shocks; the absolutely safe speed range specifically refers to the range of host operating angular velocity where no significant increase in vibration amplitude has been observed, as verified in the offline calibration experiment in step two, regardless of the combination of servo PWM beat frequencies. This controlled deceleration avoids the secondary impact that may occur during emergency braking; Through forced torque smoothing and orderly deceleration, the emergency intervention strategy can quickly break the positive energy feedback loop, pulling the system from a dangerous runaway state back to a known safe state, thereby maximizing the protection of hardware and reducing potential production losses.

[0026] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A synchronous control system for multiple servo motors on a circular loom main unit, characterized in that, include: The state representation unit is used to acquire multi-scale state information that represents the operating state of the system in real time. The risk assessment unit is used to calculate the comprehensive instability index of the system in real time based on multi-scale state information and preset system physical parameters; The control strategy switching unit is used to compare the system's overall instability index with a preset first threshold and a second threshold, and in response to the comparison result, select and execute the corresponding control strategy from the baseline control strategy, the active avoidance strategy, and the emergency intervention strategy.

2. The synchronous control system for multiple servo motors of a circular loom main unit according to claim 1, characterized in that, The multi-scale state information includes: the rate of change of macroscopic torsional vibration angular frequency, the servo current impact response time constant, and the normalized microscopic acoustic emission energy envelope integral value.

3. The synchronous control system for multiple servo motors of a circular loom main unit according to claim 1, characterized in that, The state representation unit is specifically used for: By deploying vibration sensors on the host-driven ring beam and combining them with signal processing methods, the rate of change of macroscopic torsional vibration angular frequency is obtained. By monitoring the DC bus current of each servo driver, the current surge caused by load mutation is identified and calculated, thereby obtaining the servo current surge response time constant. High-frequency stress wave signals are collected by acoustic emission sensors arranged in the mechanical contact area to obtain the normalized microscopic acoustic emission energy envelope integral value.

4. The synchronous control system for multiple servo motors of a circular loom main unit according to claim 1, characterized in that, The risk assessment unit is specifically used to: calculate the system's comprehensive instability index by combining multi-scale state information, a preset loom spindle reference working angular velocity, a set of beat frequency intervals, and the high-order torsional resonance angular frequency of the main machine structure.

5. The synchronous control system for multiple servo motors of a circular loom main unit according to claim 1, characterized in that, The execution logic of the control strategy switching unit is defined as follows: When the overall system instability index is less than or equal to the first threshold, the baseline control strategy is executed. When the overall system instability index is greater than the first threshold and less than the second threshold, an active avoidance strategy is executed. When the overall system instability index is greater than or equal to the second threshold, an emergency intervention strategy is implemented.

6. The synchronous control system for multiple servo motors of a circular loom main unit according to claim 5, characterized in that, The active avoidance strategy includes performing dynamic optimization of the pulse width modulation carrier frequency and superimposing adaptive feedforward damping torque into the servo torque command.

7. A synchronous control system for multiple servo motors of a circular loom main unit according to claim 6, characterized in that, The execution process of the dynamic optimization of the pulse width modulation carrier frequency is as follows: Based on the system's beat angle frequency set and structural resonant frequency, a risk cost function is constructed. The risk cost function is solved by numerical optimization algorithm to obtain the set of optimal carrier angular frequency offsets that minimize the function value; Apply the optimal carrier angular frequency offset set to each servo driver.

8. A synchronous control system for multiple servo motors of a circular loom main unit according to claim 6, characterized in that, The adaptive feedforward damping torque is generated in the following manner: Obtain the macroscopic torsional vibration angular velocity obtained after processing the vibration sensor signal; Based on the system's overall instability index, the first threshold, the second threshold, and the preset damping gain coefficient, a dynamic damping coefficient is generated; The adaptive feedforward damping torque is obtained by multiplying the dynamic damping coefficient by the macroscopic torsional vibration angular velocity.

9. A synchronous control system for multiple servo motors of a circular loom main unit according to claim 5, characterized in that, The emergency intervention strategy includes: forcibly smoothing the output torque of all servo motors and guiding the system to slow down in a controlled manner to a preset absolute safe speed range.

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