Variable frequency energy-saving automatic control system of centrifuge

Abstract

The present application relates to centrifuge technical field, especially centrifuge's variable frequency energy -conserving automatic control system, include: centrifuge module is used to according to centrifuge to material is separated to get target product, including to provide centrifugal power drive motor;Data processing module, including to the data acquisition unit of running data of centrifuge is gathered;Variable frequency automatic control module, including to the adjustment strategy of centrifuge is output according to neural network model main MCU;Counting adjustment module, to determine the counting frequency of timer in slave MCU according to the start and stop response time length of drive motor;Feedforward adjustment module, to determine the feedforward advance of auxiliary motor according to the phase deviation value of PWM signal;Buffer adjustment module, to determine running data buffer trigger threshold according to slave MCU instruction response deviation time length.The present application improves the real -time of centrifuge variable frequency automatic control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of centrifuges, in particular to a variable frequency energy-saving automatic control system of a centrifuge. BACKGROUND

[0002] In the industrial fields of chemical industry, pharmaceutical industry, food processing, etc., the centrifuge variable frequency energy-saving automatic control system has become the core tool for balancing energy consumption control, separation precision and production continuity. Since the system directly determines the speed adaptability, load response efficiency and energy utilization rate of the centrifuge, its control accuracy and dynamic adaptability are crucial. When the system only relies on fixed PID parameters without real-time integration of material characteristic data, the energy-saving effect will be attenuated due to the disconnection between the control strategy and the actual working condition, and even the risk of equipment overload operation may occur, resulting in rising energy consumption cost and loss of production efficiency. Although the existing variable frequency automatic control system has realized basic speed regulation, it mainly uses static control logic under single working condition, does not fully integrate multi-source data such as feeding parameters and separation effect feedback, and lacks the ability to predict dynamic load, making it difficult to balance energy-saving goals and production stability under complex production conditions. Therefore, the centrifuge variable frequency energy-saving automatic control system needs to be able to integrate multi-source working condition data and dynamically optimize control parameters.

[0003] Chinese patent publication No. CN118897472A discloses an intelligent control method and system for a variable frequency centrifuge unit. The method includes the following steps: Step 1: based on the dynamic characteristics of the variable frequency centrifuge unit, a state space model of the variable frequency centrifuge unit is established; Step 2: based on the state space model, an adaptive fuzzy neural network controller is designed to combine fuzzy logic with neural networks to control nonlinear systems. Through the update of adaptive weights, the adaptive fuzzy neural network controller can dynamically adjust to adapt to different state changes of the variable frequency centrifuge unit; the adaptive fuzzy neural network controller outputs an adaptive power matrix; Step 3: a load torque observer is used to estimate load changes and calculate a load compensation control input matrix, thereby ensuring stable operation of the variable frequency centrifuge unit under dynamic load changes; Step 4: based on the state space model, a robust H∞ controller is used to calculate a robust power matrix; the adaptive power matrix, the robust power matrix and the load compensation control input matrix are combined to calculate the final control input power matrix of the variable frequency centrifuge unit. It can be seen that the intelligent control method and system for the variable frequency centrifuge unit have the problem of insufficient real-time performance of the centrifuge variable frequency automatic control due to the long time consumption of adaptive fuzzy neural network operation and the lag of adaptive power matrix generation. SUMMARY

[0004] Therefore, the present application provides a variable frequency energy-saving automatic control system for a centrifuge to overcome the problem of insufficient real-time performance of the centrifuge variable frequency automatic control due to the long time consumption of adaptive fuzzy neural network operation and the lag of adaptive power matrix generation in the prior art.

[0005] To achieve the above object, the application provides a centrifuge variable frequency energy-saving automatic control system, comprising:

[0006] A centrifuge module is used to separate materials to obtain target products according to the centrifuge, comprising a driving motor used to provide centrifugal power, a differential used to drive a drum containing the materials to centrifuge, and a sub-motor used to drive a scraper in the centrifuge to scrape materials;

[0007] A data processing module is connected with the centrifuge module, comprising a data acquisition unit used to acquire operation data of the centrifuge, a data processing unit connected with the data acquisition unit and used to pre-process the operation data to obtain an operation state feature, and a model training unit connected with the data processing unit and used to train an initial model according to the operation state feature to obtain a neural network model;

[0008] A variable frequency automatic control module is connected with the centrifuge module and the data processing module, comprising a main MCU used to output an adjustment strategy of the centrifuge according to the neural network model, and a slave MCU connected with the main MCU and used to convert the adjustment strategy into a PWM signal to drive an IGBT frequency converter;

[0009] A counting adjustment module is connected with the variable frequency automatic control module and used to determine a counting frequency of a timer in the slave MCU according to a start-stop response time length of the driving motor;

[0010] A feedforward adjustment module is connected with the centrifuge module, the variable frequency automatic control module and the counting adjustment module, and used to determine a feedforward advance of the sub-motor according to a phase deviation value of the PWM signal;

[0011] A buffer adjustment module is connected with the variable frequency automatic control module and the feedforward adjustment module, and used to determine a running data buffer trigger threshold according to a slave MCU instruction response deviation time length.

[0012] Further, the counting adjustment module determines that real-time performance of the centrifuge variable frequency automatic control does not meet the requirements in response to the start-stop response time length of the driving motor being greater than a preset first response time length.

[0013] Further, the counting adjustment module preliminarily determines that master-slave MCU control synchronization does not meet the requirements in response to the start-stop response time length of the driving motor being greater than the preset first response time length and less than or equal to a preset second response time length, and determines whether the master-slave MCU control synchronization meets the requirements according to a phase deviation value of the PWM signal.

[0014] Further, the count adjustment module increases the count frequency of the timer in the slave MCU in response to the start-stop response time length of the driving motor being greater than the preset second response time length.

[0015] The increase amplitude of the count frequency of the timer in the slave MCU is determined by the difference between the start-stop response time length of the driving motor and the preset second response time length.

[0016] Further, the feedforward adjustment module preliminarily determines that the communication real-time performance of the master-slave MCUs does not meet the requirement in response to the phase deviation value of the PWM signal being greater than the preset second deviation value, and determines whether the communication real-time performance of the master-slave MCUs meets the requirement according to the slave MCU instruction response deviation time length.

[0017] Further, the feedforward adjustment module increases the feedforward advance of the auxiliary motor in response to the phase deviation value of the PWM signal being greater than the first deviation value and less than or equal to a preset second deviation value.

[0018] Further, the feedforward adjustment module preliminarily determines that the communication real-time performance of the master-slave MCUs does not meet the requirement in response to the phase deviation value of the PWM signal being greater than the preset second deviation value, and determines whether the communication real-time performance of the master-slave MCUs meets the requirement according to the slave MCU instruction response deviation time length.

[0019] The increase amplitude of the feedforward advance of the auxiliary motor is determined by the difference between the phase deviation value of the PWM signal and the preset first deviation value.

[0020] Further, the analysis thread adjustment module determines that the communication real-time performance of the master-slave MCUs does not meet the requirement in response to the slave MCU instruction response deviation time length being greater than a preset deviation time length, and decreases the running data cache triggering threshold.

[0021] The decrease amplitude of the running data cache triggering threshold is determined by the difference between the slave MCU instruction response deviation time length and the preset deviation time length.

[0022] Compared with the prior art, the beneficial effects of the present application are that the system sets a centrifugal module, a data processing module, a variable frequency automatic control module, a counting adjustment module, a feedforward adjustment module and a buffer adjustment module, adjusts the counting frequency of the timer in the MCU according to the start-stop response time length of the driving motor, because the motor stator inductance and rotor inertia exist inherent inertia during the operation of the centrifuge, which causes current regulation lag and thus causes slow response of motor power regulation, by increasing the counting frequency of the timer in the MCU, the current loop response bandwidth and disturbance rejection capability can be improved, the inertia effect can be overcome to shorten the power regulation lag time, ensure the timeliness of the variable frequency energy-saving automatic control, and synchronously improve the energy-saving efficiency, adjust the feedforward advance of the slave motor according to the phase deviation value of the PWM signal, because the master-slave signal transmission delay and differential mechanical transmission gap are always existing disturbance factors, which causes the slave end control to be unable to predict the phase change trend of the master end PWM signal in advance, causing the master-slave end PWM signal phase deviation to exceed the preset threshold, by increasing the feedforward advance of the slave motor, the phase difference caused by the transmission delay and mechanical gap can be compensated, so that the slave end quickly follows the master end signal to complete phase calibration, and the running data buffer trigger threshold is adjusted according to the instruction response deviation time length of the slave MCU, because the instructions issued in the master-slave MCU communication must have real-time, the small delay generated by the transmission link causes the waiting period of the slave MCU to receive instructions to be too long, and the instruction response deviation time length exceeds the preset real-time threshold, by reducing the buffer trigger threshold, the waiting period of data frame transmission can be shortened, the instructions can be quickly transmitted from the master MCU to the slave MCU, the response delay is effectively reduced, and the real-time performance of the centrifuge variable frequency automatic control is improved.

[0023] Further, the system adjusts the counting frequency of the timer in the MCU by setting the preset first response time length and the preset second response time length, because the motor stator inductance and rotor inertia exist inherent inertia during the operation of the centrifuge, which causes current regulation lag and thus causes slow response of motor power regulation, by increasing the counting frequency of the timer in the MCU, the current loop response bandwidth and disturbance rejection capability can be improved, the inertia effect can be overcome to shorten the power regulation lag time, ensure the timeliness of the variable frequency energy-saving automatic control, and synchronously improve the energy-saving efficiency, and further improve the real-time performance of the centrifuge variable frequency automatic control.

[0024] Further, the system of the present application adjusts the feed-forward advance of the auxiliary motor by setting the preset first deviation value and the preset second deviation value. Since the master-slave signal transmission delay and the differential mechanical transmission gap are always existing disturbance factors, the slave end control cannot predict the phase change trend of the master end PWM signal in advance, resulting in that the master-slave PWM signal phase deviation exceeds the preset threshold. By increasing the feed-forward advance of the auxiliary motor, the phase difference caused by the transmission delay and the mechanical gap can be compensated, so that the slave end quickly follows the master end signal to complete the phase calibration, and the real-time performance of the centrifuge variable frequency automatic control is further improved.

[0025] Further, the system of the present application adjusts the feed-forward advance of the auxiliary motor by setting the preset first deviation value and the preset second deviation value. Since the master-slave signal transmission delay and the differential mechanical transmission gap are always existing disturbance factors, the slave end control cannot predict the phase change trend of the master end PWM signal in advance, resulting in that the master-slave PWM signal phase deviation exceeds the preset threshold. By increasing the feed-forward advance of the auxiliary motor, the phase difference caused by the transmission delay and the mechanical gap can be compensated, so that the slave end quickly follows the master end signal to complete the phase calibration, and the real-time performance of the centrifuge variable frequency automatic control is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The whole structure block diagram of the variable frequency energy-saving automatic control system of the centrifuge of the embodiment of the present application is shown in the figure.

[0027] Figure 2 The partial structure schematic diagram of the variable frequency energy-saving automatic control system of the centrifuge of the embodiment of the present application is shown in the figure.

[0028] Figure 3 The logic flow chart of the process of determining the counting frequency of the timer in the slave MCU of the variable frequency energy-saving automatic control system of the centrifuge of the embodiment of the present application is shown in the figure.

[0029] Figure 4 The logic flow chart of the process of determining the feed-forward advance of the auxiliary motor of the variable frequency energy-saving automatic control system of the centrifuge of the embodiment of the present application is shown in the figure.

[0030] The reference signs are as follows: 1-driving motor, 2-auxiliary motor, 3-differential, 301-sun gear, 302-planet gear, 303-differential ring gear, 4-rotating drum, 5-scraping knife. DETAILED DESCRIPTION

[0031] In order to make the purpose and advantages of the present application more clear and explicit, the present application is further described below in combination with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present application, and do not limit the present application.

[0032] The preferred embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art will understand that the embodiments are only used to explain the technical principles of the present application and are not intended to limit the protection scope of the present application.

[0033] Please refer to Figure 1 and Figure 2 , which are the overall structure block diagram of the variable frequency energy-saving automatic control system of the centrifuge of the embodiment of the present application and the partial structure schematic diagram of the variable frequency energy-saving automatic control system of the centrifuge of the embodiment of the present application, respectively.

[0034] The variable frequency energy-saving automatic control system of the centrifuge of the present application comprises:

[0035] The centrifugal module is used to separate materials to obtain target products according to the centrifuge, and comprises a driving motor 1 used to provide centrifugal power, a differential 3 connected with the driving motor 1 and used to drive a drum 4 containing the materials to centrifuge, and a sub-motor 2 connected with the differential 3 and used to adjust the speed difference between the drum 4 and a scraper 5 to separate the centrifugal products;

[0036] The data processing module is connected with the centrifugal module, and comprises a data acquisition unit used to acquire the running data of the centrifuge, a data processing unit connected with the data acquisition unit and used to pre-process the running data to obtain a running state feature, and a model training unit connected with the data processing unit and used to train an initial model according to the running state feature to obtain a neural network model;

[0037] The variable frequency automatic control module is connected with the centrifugal module and the data processing module, respectively, and comprises a main MCU used to output the adjustment strategy of the centrifuge according to the neural network model, and a slave MCU connected with the main MCU and used to convert the adjustment strategy into a PWM signal to drive an IGBT frequency converter;

[0038] The counting adjustment module is connected with the variable frequency automatic control module, and is used to determine the counting frequency of a timer in the slave MCU according to the start-stop response time length of the driving motor 1;

[0039] The feedforward adjustment module is connected with the centrifugal module, the variable frequency automatic control module and the counting adjustment module, respectively, and is used to determine the feedforward advance of the sub-motor 2 according to the phase deviation value of the PWM signal;

[0040] The cache adjustment module is connected with the variable frequency automatic control module and the feedforward adjustment module, respectively, and is used to determine the running data cache trigger threshold according to the slave MCU instruction response deviation time length.

[0041] Specifically, the differential 3 comprises:

[0042] A sun gear 301 connected with the auxiliary motor 2 to transmit power of the auxiliary motor;

[0043] A planet gear 302 connected with the scraper 5 to transmit power to the scraper 5;

[0044] A differential ring gear 303 fixed inside the differential 3 to constrain the orbit of the planet gear 302.

[0045] Specifically, the operation data includes the vibration frequency of the centrifuge, the rotation speed of the main motor, and the power consumption of the auxiliary motor 2.

[0046] Specifically, the operation state features are the vibration amplitude of the centrifuge, the rotation speed change rate of the main motor, and the power peak value of the auxiliary motor 2.

[0047] Specifically, the preprocessing includes cleaning, de-duplication, denoising, normalization, and feature extraction.

[0048] Specifically, the initial model is a recurrent neural network structure containing an input layer, a hidden memory unit layer, and an output layer for capturing the time sequence features of the sequence data.

[0049] Specifically, the process of training the initial model according to the operation state features to obtain the neural network model is to divide the operation state feature samples into a training set, a validation set, and a test set, use the training set to optimize the parameters of the model, use the validation set to monitor the convergence trend and prevent overfitting, and finally use the test set to evaluate the prediction performance of the model, thereby outputting the neural network model.

[0050] Specifically, the neural network model includes an LSTM neural network model, an RBF neural network model, and a double neural network structure model.

[0051] Specifically, the main MCU can be an STM32H743, and the slave MCU can be an STM32F103.

[0052] Specifically, the main MCU is used to run the LSTM neural network, predict the optimal rotation speed curve of the motor according to the operation state features, and generate a variable frequency adjustment strategy for the centrifuge.

[0053] The slave MCU is used to generate a PWM signal according to the variable frequency adjustment strategy of the centrifuge to control the IGBT frequency converter to adjust the motor.

[0054] Specifically, the process of outputting the adjustment strategy for the centrifuge according to the neural network model is to input the real-time collected operation state features into the neural network model, the model calculates the predicted optimal rotation speed curve of each motor through forward propagation, and outputs the corresponding adjustment strategy according to the prediction result.

[0055] Specifically, the process of converting the regulation strategy into a PWM signal to drive the IGBT frequency converter is to calculate the PWM duty cycle and frequency according to the regulation strategy, generate a corresponding synchronous PWM signal with a dead time through a timer, and drive the switching of the IGBT bridge arm.

[0056] Specifically, the counting frequency of the timer from the MCU is the counting frequency of the timer.

[0057] Specifically, the feedforward advance of the auxiliary motor 2 is the difference between the theoretical time of issuing a control instruction to the auxiliary motor 2 and the actual time of issuing a control instruction to the auxiliary motor 2.

[0058] Specifically, the running data buffer trigger threshold is the maximum storage amount of complete data accumulated in the data acquisition buffer that triggers data processing.

[0059] In implementation, the system described in the present application adjusts the counting frequency of the timer from the MCU according to the start-stop response time of the driving motor 1 by setting a centrifugal module, a data processing module, a frequency automatic control module, a counting adjustment module, a feedforward adjustment module, and a buffer adjustment module. Since there is inherent inertia between the motor stator inductance and the rotor inertia during the operation of the centrifuge, it causes current regulation lag and thus causes slow response of motor power regulation. By increasing the counting frequency of the timer from the MCU, the current loop response bandwidth and disturbance rejection capability can be improved, the inertia effect can be overcome to shorten the power regulation lag time, the timeliness of the frequency energy-saving automatic control can be ensured to meet the standard, and the energy-saving efficiency can be improved. The feedforward advance of the auxiliary motor 2 is adjusted according to the phase deviation value of the PWM signal. Since the signal transmission delay and the differential mechanism 3 mechanical transmission gap between the master and slave ends are always present disturbance factors, the slave end control cannot predict the phase change trend of the master end PWM signal in advance, causing the phase deviation of the master and slave end PWM signals to exceed the preset threshold. By increasing the feedforward advance of the auxiliary motor 2, the phase difference caused by the transmission delay and the mechanical gap can be compensated for, and the slave end can quickly follow the master end signal to complete phase calibration. The running data buffer trigger threshold is adjusted according to the instruction response deviation time of the slave MCU. Since the real-time performance is required for the instruction issuance in the communication between the master and slave MCUs, the small delay generated by the transmission link causes the waiting period of the slave MCU to receive the instruction to be too long, and the instruction response deviation time exceeds the preset real-time threshold. By reducing the buffer trigger threshold, the waiting period of the data frame transmission can be shortened, the instruction can be transmitted from the master MCU to the slave MCU more quickly, the response delay can be effectively reduced, and the real-time performance of the frequency automatic control of the centrifuge is improved.

[0060] Please continue to see Figure 3 The figure is a logic flow chart of the process of determining the counting frequency of the timer from the MCU of the frequency energy-saving automatic control system of the centrifuge according to an embodiment of the present application.

[0061] Specifically, the count adjustment module determines that the real-time performance of the centrifuge variable frequency self-control meets the requirements in response to the start-stop response time length of the driving motor 1 being less than or equal to a preset first response time length.

[0062] The count adjustment module determines that the real-time performance of the centrifuge variable frequency self-control does not meet the requirements in response to the start-stop response time length of the driving motor 1 being greater than the preset first response time length.

[0063] Specifically, the count adjustment module preliminarily determines that the master-slave MCU control synchronization does not meet the requirements in response to the start-stop response time length of the driving motor 1 being greater than the preset first response time length and less than or equal to a preset second response time length, and determines whether the master-slave MCU control synchronization meets the requirements according to the phase deviation value of the PWM signal.

[0064] It can be understood that the preset first response time length is less than the preset second response time length, and the three intervals divided by the preset first response time length and the preset second response time length correspond to three situations respectively.

[0065] The first interval is that the start-stop response time length of the driving motor 1 is less than or equal to the preset first response time length, and the corresponding situation is that the real-time performance of the centrifuge variable frequency self-control is determined to meet the requirements.

[0066] The second interval is that the start-stop response time length of the driving motor 1 is greater than the preset first response time length and less than or equal to the preset second response time length, and the corresponding situation is that, due to the master-slave signal transmission delay and the differential mechanism 3 mechanical transmission gap being always existing disturbance factors, the slave end control cannot predict the phase change trend of the master end PWM signal in advance, causing the master-slave end PWM signal phase deviation to exceed the preset threshold.

[0067] The third interval is that the start-stop response time length of the driving motor 1 is greater than the preset second response time length, and the corresponding situation is that, due to the existence of inherent inertia between the motor stator inductance and the rotor inertia in the centrifuge operation, the current regulation lags behind, thereby causing the motor power regulation response to be slow.

[0068] It can be understood that in the variable frequency energy-saving automatic control system of the centrifuge, the preset first response time and the preset second response time are used to represent the real-time performance of the centrifuge variable frequency automatic control, the core logic is to convert the real-time performance of the centrifuge variable frequency automatic control into a quantifiable start-stop response time interval judgment of the driving motor 1, the preset first response time is a demarcation line for determining whether the real-time performance of the centrifuge variable frequency automatic control meets the requirements, and the preset second response time is a demarcation line for distinguishing the severity of the centrifuge variable frequency automatic control not meeting the requirements, thereby providing a quantitative judgment basis for targeted optimization under different delay scenarios. The preset first response time and the preset second response time can be set according to actual working conditions. The preset first response time and the preset second response time are set to ensure the real-time performance and practicality of the centrifuge variable frequency automatic control. Alternatively, the preset first response time and the preset second response time are determined through a limited number of tests by evaluating the variable frequency control effect of different response times on the centrifuge. The determined preset first response time and preset second response time should meet the requirements that they cannot be too small and cannot cause too much interference to the variable frequency control process of the centrifuge. For example, the preset first response time is generally selected in the range of [290 ms, 310 ms], and the preset second response time is generally selected in the range of [490 ms, 510 ms].

[0069] Preferably, the preferred embodiment of the preset first response time is 300 ms, and the preferred embodiment of the preset second response time is 500 ms.

[0070] Specifically, the start-stop response time of the driving motor 1 is the time length from when the main motor receives a start or stop instruction to when the instruction is completed.

[0071] Specifically, the counting adjustment module increases the counting frequency of the slave MCU timer in response to the start-stop response time of the driving motor 1 being greater than the preset second response time.

[0072] The increase in the counting frequency of the slave MCU timer is determined by the difference between the start-stop response time of the driving motor 1 and the preset second response time.

[0073] Specifically, when the difference between the preset first response time and the start-stop response time of the driving motor 1 is within 50 ms, the counting frequency of the slave MCU timer is increased to 1.1 times the original frequency. When the difference between the preset first response time and the start-stop response time of the driving motor 1 exceeds 50 ms, the counting frequency of the slave MCU timer is increased by 0.1 MHz for every 20 ms in addition to the increase to 1.1 times the original frequency. For example, when the difference between the preset first response time and the start-stop response time of the driving motor 1 is 90 ms, and the current counting frequency of the slave MCU timer is 10 MHz, the increased counting frequency of the slave MCU timer is 11.2 MHz.

[0074] In the implementation, the system described in the application adjusts the counting frequency of the timer in the MCU by setting the preset first response duration and the preset second response duration. Due to the inherent inertia of the motor stator inductance and the rotor inertia in the operation of the centrifuge, the current regulation hysteresis is caused, and then the power regulation response is delayed. By increasing the counting frequency of the timer in the MCU, the current loop response bandwidth and the anti-disturbance ability can be improved, the inertia influence can be overcome to shorten the power regulation hysteresis time, the timeliness of the frequency conversion energy-saving self-control can be ensured to meet the standard, the energy-saving efficiency can be improved synchronously, and the real-time performance of the frequency conversion self-control of the centrifuge is further improved.

[0075] Please continue to refer to Figure 4 As shown in the figure, it is a logic flow chart of the feedforward advance process of the auxiliary motor 2 of the frequency conversion energy-saving self-control system of the centrifuge according to the embodiment of the application.

[0076] Specifically, the feedforward regulation module determines that the master-slave MCU control synchronization meets the requirements in response to the phase deviation value of the PWM signal being less than the preset first deviation value.

[0077] The feedforward regulation module determines that the master-slave MCU control synchronization does not meet the requirements in response to the phase deviation value of the PWM signal being greater than the preset first deviation value.

[0078] Specifically, the feedforward regulation module increases the feedforward advance of the auxiliary motor 2 in response to the phase deviation value of the PWM signal being greater than the first deviation value and less than or equal to the preset second deviation value.

[0079] Specifically, the feedforward regulation module preliminarily determines that the communication real-time performance of the master-slave MCU does not meet the requirements in response to the phase deviation value of the PWM signal being greater than the preset second deviation value, and determines whether the communication real-time performance of the master-slave MCU meets the requirements according to the slave MCU instruction response deviation duration.

[0080] It can be understood that the preset first deviation value is less than the preset second deviation value, and the three intervals divided by the preset first deviation value and the preset second deviation value correspond to three situations respectively.

[0081] The first interval is that the phase deviation value of the PWM signal is less than or equal to the preset first deviation value, and the corresponding situation is that the master-slave MCU control synchronization meets the requirements.

[0082] The second interval is that the phase deviation value of the PWM signal is greater than the preset first deviation value and less than or equal to the preset second deviation value, and the corresponding situation is that the master-slave end signal transmission delay and the differential mechanism 3 mechanical transmission gap are always existing disturbance factors, so that the slave end control cannot predict the phase change trend of the master end PWM signal in advance, and the phase deviation of the master-slave end PWM signal exceeds the preset threshold.

[0083] The third interval is that the phase deviation value of the PWM signal is greater than the preset second deviation value. The corresponding case is that the master-slave MCU communication must have real-time performance, and the small delay generated by the transmission link causes the waiting period of the slave MCU receiving the command to be too long, and the command response deviation duration exceeds the preset real-time threshold.

[0084] It can be understood that in the frequency conversion energy-saving automatic control system of the centrifuge, the preset first deviation value and the preset second deviation value are used to represent the master-slave MCU control synchronization, and the core logic is to convert the master-slave MCU control synchronization into a quantifiable PWM signal deviation value interval judgment. The preset first deviation value is a demarcation line for determining whether the master-slave MCU control synchronization meets the standard, and the core function is to identify whether the synchronization meets the basic operation requirements of the system. The preset second deviation value is a demarcation line for determining the severity of the synchronization problem, and the core function is to distinguish the type of the synchronization problem that does not meet the requirements. The preset first deviation value and the preset second deviation value can be set according to the actual working conditions. The preset first deviation value and the preset second deviation value are set to ensure the real-time performance and practicality of the frequency conversion automatic control of the centrifuge. Alternatively, the preset first deviation value and the preset second deviation value are determined through a limited number of tests by evaluating the effect of different response deviation values on the frequency conversion automatic control of the centrifuge. The determined preset first deviation value and the preset second deviation value should meet the requirements that they cannot be too small and cannot cause too much interference to the frequency conversion automatic control process of the centrifuge. For example, the preset first deviation value is generally selected in the range of [4μs, 6μs], and the preset second deviation value is generally selected in the range of [9μs, 11μs].

[0085] Preferably, the preferred embodiment of the preset first deviation value is 5μs, and the preferred embodiment of the preset second deviation value is 10μs.

[0086] Specifically, the phase deviation value of the PWM signal is the time difference when the two associated PWM signals are triggered at the corresponding time points.

[0087] Specifically, the associated PWM signals are PWM signals that work synchronously or simultaneously act on the same drive unit.

[0088] Specifically, the increase range of the feedforward advance of the auxiliary motor 2 is determined by the difference between the phase deviation value of the PWM signal and the preset first deviation value.

[0089] Specifically, when the difference between the phase deviation value of the PWM signal and the preset first deviation value is within 2 mu s, the feedforward advance of the auxiliary motor 2 is increased by 1.1 times of the original, and when the difference between the phase deviation value of the PWM signal and the preset first deviation value exceeds 2 mu s, the feedforward advance of the auxiliary motor 2 is increased by 0.2 for every 1 mu s on the basis of being increased by 1.1 times of the original, for example, when the difference between the phase deviation value of the PWM signal and the preset first deviation value is 4 mu s, the feedforward advance of the auxiliary motor 2 is 10, and the increased feedforward advance of the auxiliary motor 2 is 10*1.1+0.2*2=11.4.

[0090] In the implementation, the system adjusts the feedforward advance of the auxiliary motor 2 by setting the preset first deviation value and the preset second deviation value. Since the master-slave signal transmission delay and the differential 3 mechanical transmission gap are always present disturbance factors, the slave end control cannot predict the phase change trend of the master end PWM signal in advance, resulting in the master-slave PWM signal phase deviation exceeding the preset threshold. By increasing the feedforward advance of the auxiliary motor 2, the phase difference caused by the transmission delay and the mechanical gap can be compensated, the slave end can quickly follow the master end signal to complete the phase calibration, and the real-time performance of the centrifuge variable frequency control is further improved.

[0091] Specifically, the parsing thread adjustment module determines that the communication real-time performance of the master-slave MCUs meets the requirements in response to the slave MCU instruction response deviation time being less than or equal to the preset deviation time.

[0092] The parsing thread adjustment module determines that the communication real-time performance of the master-slave MCUs does not meet the requirements and reduces the running data buffer triggering threshold in response to the slave MCU instruction response deviation time being greater than the preset deviation time.

[0093] It can be understood that the two intervals divided by the preset deviation time correspond to two situations respectively.

[0094] The first interval is that the slave MCU instruction response deviation time is less than or equal to the preset deviation time, and the corresponding situation is that the communication real-time performance of the master-slave MCUs meets the requirements.

[0095] The second interval is that the slave MCU instruction response deviation time is greater than the preset deviation time, and the corresponding situation is that the instruction response deviation time exceeds the preset real-time threshold due to the real-time requirement of the instruction issuing in the master-slave MCU communication and the small delay of the transmission link causing the waiting period of the slave MCU receiving the instruction to be too long.

[0096] It can be understood that in the variable frequency energy-saving automatic control system of the centrifuge, the preset deviation time length is used to represent the communication real-time of the master-slave MCU, and the core logic is to convert the communication real-time of the master-slave MCU into a quantifiable unit time interval judgment of the response deviation time length of the slave MCU. The preset deviation time length is the demarcation line for determining whether the communication real-time of the master-slave MCU meets the standard, and the core role is to determine whether the communication real-time meets the basic operation requirements of the system. The preset deviation can be set according to the actual working condition. The setting of the preset deviation time length aims to ensure the real-time and practicality of the variable frequency automatic control of the centrifuge. Alternatively, the preset deviation time length is determined through a limited number of tests by evaluating the variable frequency control effect of the centrifuge under different response deviation time lengths. The determined preset deviation time length should meet the requirements that it cannot be too small and cannot cause too much interference to the variable frequency control process of the centrifuge. Exemplarily, the preset deviation time length is generally selected in the range of [9μs, 11μs].

[0097] Preferably, the preferred embodiment of the preset deviation time length is 10μs.

[0098] Specifically, the slave MCU instruction response deviation time length is the difference between the actual time length and the theoretical time length from when the master MCU issues an instruction to when the slave MCU receives the instruction and responds.

[0099] Specifically, the reduction range of the running data cache trigger threshold is determined by the difference between the slave MCU instruction response deviation time length and the preset deviation time length.

[0100] Specifically, when the difference between the slave MCU instruction response deviation time length and the preset deviation time length is within 2μs, the running data cache trigger threshold is reduced to 0.9 times of the original value. When the difference between the slave MCU instruction response deviation time length and the preset deviation time length exceeds 10μs, the running data cache trigger threshold is reduced by 5KB for every 1μs in addition to the reduction to 0.9 times of the original value. For example, when the difference between the slave MCU instruction response deviation time length and the preset deviation time length is 4μs, and the current running data cache trigger threshold is 150KB, the reduced running data cache trigger threshold is 150x0.9-5x2=125KB.

[0101] In implementation, the system of the present application adjusts the running data cache trigger threshold by setting the preset deviation time length. Since the instruction issuing in the master-slave MCU communication must have real-time, the small delay caused by the transmission link leads to an excessively long waiting period for the slave MCU to receive the instruction, the instruction response deviation time length exceeds the preset real-time threshold, and by reducing the cache trigger threshold, the waiting period of data frame transmission can be shortened, the instruction can be transmitted from the master MCU to the slave MCU more quickly, the response delay is effectively reduced, and the real-time of the variable frequency automatic control of the centrifuge is further improved.

[0102] The technical scheme of the present application has been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical schemes after the changes or replacements will all fall within the protection scope of the present application.

Claims

1. A variable frequency energy-saving automatic control system for a centrifuge, characterized in that, include: A centrifugal module for separating materials in a centrifuge to obtain a target product includes a drive motor for providing centrifugal power, a differential connected to the drive motor for driving a drum containing the material to centrifuge, and an auxiliary motor connected to the differential for driving a scraper in the centrifuge to scrape the material. The data processing module, which is connected to the centrifugation module, includes a data acquisition unit for collecting the operating data of the centrifuge, a data processing unit connected to the data acquisition unit for preprocessing the operating data to obtain operating status characteristics, and a model training unit connected to the data processing unit for training an initial model based on the operating status characteristics to obtain a neural network model. The variable frequency control module is connected to the centrifugation module and the data processing module respectively, and includes a main MCU for outputting the adjustment strategy of the centrifuge according to the neural network model and a slave MCU connected to the main MCU for converting the adjustment strategy into a PWM signal to drive the IGBT frequency converter. A counting adjustment module, which is connected to the frequency conversion automatic control module, is used to determine the counting frequency of the timer in the MCU based on the start and stop response time of the drive motor. The feedforward adjustment module is connected to the centrifugal module, the frequency conversion automatic control module and the counting adjustment module respectively, and is used to determine the feedforward advance of the auxiliary motor based on the phase deviation value of the PWM signal. The buffer adjustment module is connected to the frequency conversion automatic control module and the feedforward adjustment module respectively, and is used to determine the running data buffer trigger threshold based on the deviation time from the MCU instruction response.

2. The variable frequency energy-saving automatic control system for a centrifuge according to claim 1, characterized in that, The counting adjustment module's response time to the start / stop of the drive motor is longer than the preset first response time, indicating that the real-time performance of the centrifuge's frequency conversion automatic control does not meet the requirements.

3. The variable frequency energy-saving automatic control system for a centrifuge according to claim 2, characterized in that, The counting adjustment module responds to the start / stop response time of the drive motor when the response time is greater than the preset first response time and less than or equal to the preset second response time. It initially determines that the master-slave MCU control synchronization does not meet the requirements, and determines whether the master-slave MCU control synchronization meets the requirements based on the phase deviation value of the PWM signal.

4. The variable frequency energy-saving automatic control system for a centrifuge according to claim 3, characterized in that, The counting adjustment module responds to the start / stop response time of the drive motor being longer than the preset second response time by increasing the counting frequency of the timer in the MCU; The increase in the counting frequency of the timer from the MCU is determined by the difference between the start / stop response time of the drive motor and the preset second response time.

5. The variable frequency energy-saving automatic control system for a centrifuge according to claim 4, characterized in that, The feedforward adjustment module responds to the PWM signal when the phase deviation value is greater than the preset first deviation value, and determines that the synchronization of the master and slave MCU control does not meet the requirements.

6. The variable frequency energy-saving automatic control system for a centrifuge according to claim 5, characterized in that, The feedforward adjustment module responds to the phase deviation value of the PWM signal being greater than the first deviation value and less than or equal to the preset second deviation value, thereby increasing the feedforward advance of the auxiliary motor.

7. The variable frequency energy-saving automatic control system for a centrifuge according to claim 6, characterized in that, The feedforward adjustment module responds to the PWM signal if the phase deviation value is greater than the preset second deviation value. It initially determines that the real-time communication between the master and slave MCUs does not meet the requirements, and determines whether the real-time communication between the master and slave MCUs meets the requirements based on the deviation time of the slave MCU instruction response.

8. The variable frequency energy-saving automatic control system for a centrifuge according to claim 7, characterized in that, The increase in the feedforward advance of the auxiliary motor is determined by the difference between the phase deviation value of the PWM signal and the preset first deviation value.

9. The variable frequency energy-saving automatic control system for a centrifuge according to claim 8, characterized in that, The cache adjustment module responds when the deviation time of the MCU instruction response exceeds the preset deviation time, determines that the real-time communication between the master and slave MCUs does not meet the requirements, and reduces the running data cache trigger threshold.

10. The variable frequency energy-saving automatic control system for a centrifuge according to claim 9, characterized in that, The reduction in the running data cache trigger threshold is determined by the difference between the deviation duration from the MCU instruction response and the preset deviation duration.

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