Magnetorheological polishing liquid supply system and method based on injection technology

Abstract

The invention discloses a magnetorheological polishing liquid supply system and method based on a jet technology, and relates to the technical field of magnetorheological polishing, the magnetorheological polishing liquid supply system comprises a liquid storage and conveying module, the liquid storage and conveying module comprises a liquid storage device, a conveying device and a pulsation attenuation module, and the magnetorheological pulsation attenuation module is provided with a magnetorheological pulsation attenuator which is connected in series between an outlet of a servo variable pump and a conveying pipeline; the spraying execution module comprises a nozzle and a position adjusting assembly; the multi-dimensional detection module comprises a visual sensor, a Coriolis flow meter and an MEMS pressure sensor; the modeling and predicting module is used for calculating pipeline resistance according to the relative position of the nozzle and the workpiece and predicting pulsation by decomposing a pump pulsation rule through Fourier transform; and the dynamic regulation and control module is used for controlling the attenuator to counteract the pulsation according to the pulsation prediction output reverse current, and regulating the displacement and the rotating speed of the pump in real time through a fuzzy PID algorithm in combination with preset target flow and pressure. The problem that in the prior art, the injection parameter control precision is limited is solved, and high-precision regulation and control are achieved.

Description

Technical Field

[0001] This invention relates to the field of magnetorheological polishing technology, and more specifically, to a magnetorheological polishing slurry supply system and method based on jetting technology. Background Technology

[0002] A magnetorheological polishing slurry supply system and method based on jetting technology focuses on the dynamic supply and precise control of magnetorheological polishing slurry. The core revolves around the stable performance of the magnetorheological effect, the precise control of polishing slurry jetting parameters, and the adaptability to precision machining scenarios. It is suitable for high-precision surface treatment of workpieces such as optical components, automotive parts, and semiconductor wafers. It not only covers the core principle application of magnetorheological polishing technology, but also integrates key technologies such as fluid transport regulation, jetting execution, and intelligent control, providing a stable and reliable polishing slurry supply solution for deterministic precision polishing.

[0003] Shortcomings of existing technology: The precision of spray parameter control is limited, and nozzle outlet flow and pressure are easily affected by pipeline resistance and pump pulsation, making it difficult to adapt to the polishing requirements of different workpieces. Existing solutions mostly adopt single closed-loop control (such as adjusting only the pump speed), without considering the "resistance-pulsation" coupling interference, resulting in control lag or overshoot. This solution achieves high-precision control through a composite control strategy of "dual-source interference decoupling + predictive compensation" combined with structural innovation.

[0004] To address the above problems, this invention proposes a solution. Summary of the Invention

[0005] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a magnetorheological polishing slurry supply system and method based on jetting technology, which solves the problems mentioned in the background art through a dual-source interference decoupling + predictive compensation composite control strategy.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A magnetorheological polishing slurry supply system based on jetting technology includes a slurry storage and delivery module, a pulsation attenuation module, a jetting execution module, a multi-dimensional detection module, a modeling and prediction module, and a dynamic control module, with connections between the modules. A liquid storage and delivery module includes a liquid storage device and a delivery device. The liquid storage device is used to store magnetorheological polishing liquid, and the delivery device provides power for delivering the magnetorheological polishing liquid. The pulsation attenuation module is equipped with a magnetorheological pulsation attenuator connected in series between the outlet of the servo variable pump and the delivery pipeline. The spraying execution module includes a nozzle and a position adjustment component. The nozzle is used to directionally spray magnetorheological polishing fluid onto the surface of the workpiece to be polished. The position adjustment component drives the nozzle to move. The multi-dimensional detection module includes a vision sensor, a Coriolis flow meter, and a MEMS pressure sensor; the vision sensor acquires the relative position of the nozzle and the workpiece; the Coriolis flow meter and the MEMS pressure sensor acquire the pipeline flow rate and pressure, respectively; The modeling and prediction module calculates the pipeline resistance based on the relative position of the nozzle and the workpiece, and predicts the pulsation by decomposing the pump body pulsation law through Fourier transform. The dynamic control module uses a reverse current control attenuator to counteract pulsation by predicting pulsation output. Combined with preset target flow and pressure, it adjusts the pump's displacement and speed in real time using a fuzzy PID algorithm.

[0007] In a preferred embodiment, the conveying device includes a servo variable pump, which changes the output flow rate and pressure by adjusting the displacement and motor speed.

[0008] In a preferred embodiment, the magnetorheological pulsation attenuator consists of a ring electromagnet and a magnetorheological fluid chamber. The ring electromagnet adjusts the magnetic field strength by receiving a control current, thereby changing the viscosity of the magnetorheological fluid inside the magnetorheological fluid chamber and forming variable damping to counteract pump body pulsation.

[0009] In a preferred embodiment, the position adjustment component drives the nozzle movement as follows: The position adjustment component uses a four-axis linkage robotic arm with a nozzle fixture installed at the end of the robotic arm. It monitors the contact force between the nozzle and the workpiece in real time and scans the three-dimensional contour of the workpiece through a vision sensor. The control system automatically generates the nozzle motion path based on the contour data: for planar workpieces, an S-shaped reciprocating path is used; for curved workpieces, a spiral path with equal arc length is used. The robotic arm motion controller and the spray control system communicate via EtherCAT bus. When the robotic arm reaches the position to be polished, the spray signal is triggered; when it leaves, the spray is turned off to avoid wasting polishing fluid by spraying dry.

[0010] In a preferred embodiment, the step of using the vision sensor to acquire the relative position of the nozzle and the workpiece is as follows: The industrial vision sensor is fixed to the side of the robotic arm, with the lens axis at a 45° angle to the nozzle spray direction; A checkerboard calibration plate is attached to the surface of the workpiece, calibration images at different positions are collected, and the transformation matrix between the sensor coordinate system and the robot arm coordinate system is calculated using the Zhang Zhengyou calibration method to establish coordinate association. After the system starts up, the vision sensor continuously acquires images and transmits them to the control system in real time through the industrial camera SDK. An adaptive threshold segmentation algorithm is used to remove background interference and extract the contour features of the nozzle tip and the workpiece edge. Based on the calibrated coordinate transformation matrix, the coordinates of the nozzle center and the workpiece polishing point in the image are transformed to the same robotic arm coordinate system; The relative position deviation is calculated based on the nozzle center coordinates and the workpiece polishing point coordinates. The deviation data is then sent to the position adjustment component for dynamic correction of the nozzle position.

[0011] In a preferred embodiment, the Coriolis flow meter collects pipeline flow as follows: Connect the Coriolis flow meter in series in the pipeline before the nozzle inlet, with the flow meter axis coaxial with the pipeline axis; After the system is powered on, the flow meter performs a self-test and sends an initialization status to the control system through the communication interface; The flow meter has a built-in vibration sensor that detects the phase difference in the pipe body caused by the Coriolis force generated during fluid flow and outputs the raw flow signal in real time. After the signal is digitized by the internal AD converter of the flow meter, the high-frequency noise caused by pump vibration is removed by digital filtering to obtain the instantaneous flow value; The control system receives several instantaneous flow values ​​and performs a moving average to obtain a stable flow value.

[0012] In a preferred embodiment, the steps for the MEMS pressure sensor to acquire pipeline pressure are as follows: The MEMS pressure sensor is installed in the side hole of the nozzle inlet pipe through a threaded interface, with the sensor's sensitive surface perpendicular to the fluid direction. Pressure is applied using a standard pressure source, the sensor output voltage value is recorded, and a pressure-voltage conversion curve is obtained by fitting the data. The sensor detects the fluid pressure in the pipeline in real time, converts the pressure signal into an analog voltage signal, and transmits it to the AD acquisition card of the control system after the signal conditioning circuit. The collected pressure signal is subjected to spectrum analysis to extract the fundamental frequency and harmonic components of the pump body pulsation, and the average pressure value is calculated at the same time. The control system compares the average pressure value with the target pressure and calculates the deviation ΔP. When the absolute value of ΔP is greater than 0.05 MPa, it sends a pressure adjustment command to the delivery module.

[0013] In a preferred embodiment, the modeling and prediction module is implemented as follows: Define pipeline structure parameters, collect real-time three-dimensional coordinates of nozzles, and calculate the actual length of pipeline based on the initial fixed length of pipeline; The head loss along the pipeline and the local head loss are calculated based on the Darcy-Weisbach formula. The total head loss of the pipeline is the sum of the head loss along the pipeline and the local head loss. The raw signal of pump outlet pressure pulsation is acquired by a MEMS pressure sensor, and the raw signal is preprocessed. The preprocessed signal is subjected to a fast Fourier transform to obtain a frequency domain signal, and the main frequency components are extracted from the frequency domain signal. The fundamental frequency and harmonic frequencies of pump body pulsation are identified by spectrum analysis, and the amplitude and phase of each frequency component are recorded. Based on the results of Fast Fourier Transform decomposition, a time-domain prediction model for pulsation is established to predict pulsations.

[0014] In a preferred embodiment, the dynamic control module is implemented as follows: The reverse compensation current is calculated using a proportional-integral control algorithm based on the predicted value of pump body pulsation. The ring electromagnet generates a corresponding magnetic field strength based on the received reverse compensation current, changes the apparent viscosity of the internal magnetorheological fluid, and forms variable damping. When the predicted pulsation is a positive peak, the damping increases, and when it is a negative peak, the damping decreases, thus actively counteracting the pump body pressure fluctuation. The actual flow rate and actual pressure in the pipeline are collected by Coriolis flow meter and MEMS pressure sensor respectively. The deviation between the actual value and the target value and the integral of the deviation are calculated by combining the preset target flow rate and target pressure. Based on the fuzzy PID algorithm, the proportional coefficient and integral coefficient are dynamically adjusted according to the flow deviation and the integral of the deviation to output the pump's displacement adjustment amount. The displacement correction is achieved by changing the swashplate angle of the servo variable pump. Similarly, based on the pressure deviation and the integral of the deviation, the corresponding proportional coefficient and integral coefficient are dynamically adjusted to adjust the speed of the output pump, and the pressure correction is achieved by changing the speed of the drive motor. To address the coupling effect between displacement and speed regulation, an offline-calibrated decoupling coefficient is introduced to cross-correct the displacement and speed regulation values. The system collects real-time data on the actual pulsation at the attenuator outlet, as well as the actual flow and pressure data in the pipeline. It continuously calculates control errors and dynamically corrects the reverse compensation current and the pump's displacement and speed adjustment parameters.

[0015] A method for supplying magnetorheological polishing slurry based on jetting technology includes the following steps: The relative position of the nozzle and the workpiece is acquired by a vision sensor, and the flow rate and pressure in the pipeline are acquired by a Coriolis force flow meter and a MEMS pressure sensor, respectively. The pipeline resistance is calculated based on the relative position of the nozzle and the workpiece, and the pulsation is predicted by decomposing the pump body pulsation law through Fourier transform. The pulsation is counteracted by a reverse current control attenuator based on the pulsation prediction output. Combined with preset target flow and pressure, the pump's displacement and speed are adjusted in real time using a fuzzy PID algorithm.

[0016] The technical effects and advantages of the magnetorheological polishing slurry supply system and method based on jetting technology of the present invention are as follows: 1. This invention constructs a "resistance-pulsation" dual-source interference model, dynamically calculates pipeline resistance by combining the relative position of the nozzle and workpiece captured in real time by a visual sensor, decomposes the pump pulsation law using Fourier transform to achieve accurate prediction, and then relies on a "dual closed-loop + feedforward compensation" control structure to actively cancel pump pulsation by outputting a reverse compensation current through a magnetorheological pulsation attenuator. At the same time, the displacement and speed of the servo variable pump are adjusted in real time by a fuzzy PID algorithm, effectively suppressing pipeline pressure fluctuations (pulsation amplitude ≤ 0.5% of rated pressure) and flow deviations (≤ ±1%), significantly improving the stability and accuracy of polishing fluid supply, providing constant and controllable polishing power for workpiece processing, and significantly reducing processing defects caused by parameter fluctuations.

[0017] 2. This invention integrates a dynamic matching library of "workpiece features and parameters," offline storing the mapping relationship between workpieces of different materials and surface roughness and the optimal spray pressure and flow rate. During processing, the initial parameters are quickly recalled through visual recognition and dynamically corrected by combining real-time flow and pressure feedback. This achieves adaptive matching between the workpiece and polishing parameters, meeting the high-precision polishing requirements of different types of workpieces such as optical lenses and mold steel parts without repeated manual adjustments. This not only broadens the applicability of the system but also simplifies the operation process and shortens the process preparation time. At the same time, through the design of polishing fluid recycling and efficient spraying method, polishing fluid waste is reduced, processing costs and environmental pressure are lowered, and processing quality, efficiency and economy are balanced. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a magnetorheological polishing fluid supply system based on jetting technology according to the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of a magnetorheological polishing fluid supply method based on jetting technology according to the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1, Figure 1 The present invention provides a magnetorheological polishing fluid supply system based on jetting technology.

[0022] A liquid storage and delivery module includes a liquid storage device and a delivery device. The liquid storage device is used to store magnetorheological polishing liquid, and the delivery device provides power for delivering the magnetorheological polishing liquid. The liquid storage device uses a stainless steel storage tank with a volume of 50-200L. The bottom is designed with a 15° inclined structure to ensure that the polishing liquid is completely discharged without residue. An ultrasonic disperser (power 500-1000W, frequency 20-40kHz) is installed at the top of the tank to break up the agglomeration of magnetic particles through high-frequency vibration. A spiral stirrer is set at the center of the bottom of the tank to continuously and gently stir and prevent particles from settling.

[0023] The conveying device includes a servo variable pump, which changes the output flow rate and pressure by adjusting the displacement and motor speed; an axial piston servo variable pump is selected, with the pump inlet connected to the outlet of the liquid storage tank through a flexible hose, and a one-way valve installed at the outlet to prevent the polishing liquid from flowing back; the pump body integrates a displacement sensor and a speed encoder to provide real-time feedback of operating parameters.

[0024] The operation process of the liquid storage device and the conveying device is as follows: After the system is powered on, the ultrasonic disperser and spiral stirrer are started first in the storage tank. After the temperature sensor detects that the polishing fluid temperature has stabilized at 25°C, the servo variable pump starts with an initial parameter of 50% displacement and 1000 r / min to slowly deliver the polishing fluid to the subsequent pipeline to avoid instantaneous pressure shock. Based on the displacement and speed adjustment output by the intelligent control module, the servo variable pump adjusts the swashplate angle and motor speed in real time to ensure that the outlet flow and pressure are stable at the target values. At the same time, the liquid level sensor feeds back liquid level data every 100ms. When the liquid level is lower than 10%, the pump will automatically stop running and issue a liquid replenishment prompt. Upon receiving the shutdown signal, the pump first runs at 20% displacement and 500 r / min for 10 seconds, then the motor is turned off; the agitator in the storage tank continues to run for 30 seconds before stopping, and the ultrasonic disperser is simultaneously turned off, completing the entire cycle.

[0025] The pulsation attenuation module is equipped with a magnetorheological pulsation attenuator, which is connected in series between the outlet of the servo variable pump and the delivery pipeline. It consists of a ring electromagnet and a magnetorheological fluid chamber. The magnetorheological fluid chamber adopts a cylindrical cavity with flanges at both ends. The inner wall of the cavity is coated with a wear-resistant ceramic coating to reduce wear during the flow of the magnetorheological fluid. The two ends of the cavity are designed with tapered interfaces, which are connected to the outlet pipeline of the servo variable pump and the downstream delivery pipeline through high-strength sealing gaskets to ensure a pressure resistance of ≥10MPa (higher than the maximum output pressure of the pump) and avoid leakage. The toroidal electromagnet is a multi-winding toroidal electromagnet, which is sleeved outside the magnetorheological fluid cavity, maintaining a 5-10mm gap with the outer wall of the fluid cavity. The electromagnet is wrapped with a silicon steel sheet shielding layer to improve the magnetic field utilization rate. The electromagnet leads are connected to an external controllable power supply. Disconnect the pipeline between the outlet of the servo variable pump and the main delivery pipeline, and connect the magnetorheological pulsation attenuator in series through flange connection to ensure that the axis of the liquid chamber is coaxial with the axis of the pipeline to avoid sudden changes in local resistance due to eccentricity; introduce clean water into the pipeline, pressurize it to 1.5 times the rated pressure and hold the pressure for 30 minutes, check the interface and the cavity for leakage, and confirm that the integrated seal is reliable. The annular electromagnet adjusts the magnetic field strength by receiving control current, thereby changing the viscosity of the magnetorheological fluid inside the magnetorheological fluid chamber and forming variable damping to counteract pump body pulsation. The magnetic field strength was measured at the central axis of the magnetorheological fluid cavity using a gaussmeter. When a current of 0-5A was applied to the electromagnet, the magnetic field strength value was recorded every 0.1A. The current-magnetic field curve was obtained by fitting, ensuring that the magnetic field strength adjustment range covered 50-500mT (to meet the variable viscosity requirements of the magnetorheological fluid). A magnetorheological fluid with an adjustable yield stress range of 1-10 kPa (based on silicone oil, with a magnetic particle volume fraction of 30-50%) is selected and injected into the liquid cavity to full capacity. When the pump output pressure pulsates, the control system outputs a target current value according to the pulsation prediction model, which generates a corresponding magnetic field through an electromagnet. When the magnetic field is enhanced, the magnetic particles form a chain structure along the direction of the magnetic field, and the viscosity of the magnetorheological fluid inside the liquid cavity increases (damping increases), hindering the transmission of pulsation. When the magnetic field is weakened, the particle chain disintegrates, the viscosity decreases (damping decreases), and a stable flow rate is allowed to pass through, achieving dynamic cancellation of "strong pulsation, large damping; weak pulsation, small damping". A high-frequency pressure sensor (sampling frequency 1kHz) is installed at the outlet of the attenuator to monitor the attenuated pressure pulsation amplitude in real time. The measured pulsation amplitude is compared with the target value (≤0.5% of rated pressure), and the electromagnet control current is corrected by the PID algorithm (e.g., when the measured pulsation exceeds the limit, the current is increased by 0.1-0.5A to enhance damping) to ensure stable attenuation effect.

[0026] It should be noted that the pulsation attenuation module can utilize the magnetic field response characteristics of magnetorheological fluid to dynamically adjust the damping to counteract pump body pulsation, control the pipeline pressure fluctuation amplitude within 0.5%, and provide a stable pressure base for subsequent injection stages.

[0027] The spraying execution module includes a nozzle and a position adjustment component. The nozzle is used to directionally spray magnetorheological polishing fluid onto the surface of the workpiece to be polished. The position adjustment component drives the nozzle to move, so that the nozzle and the workpiece form a dynamic relative position relationship. The modular nozzle structure is designed according to the needs of polishing scenarios. It is made of wear-resistant ceramic material, and the outlet shape is replaceable. It can be quickly connected to the pipeline through the threaded interface. The nozzle is designed with a tapered flow channel inside to reduce the flow resistance of polishing fluid. A miniature laser positioner is installed at the end of the nozzle to pre-aim the area to be polished with the laser beam, ensuring that the deviation between the spray center and the target area is ≤0.05mm; a universal joint is set at the connection between the nozzle and the pipeline, and an angle sensor is used to monitor the spray direction in real time. The angle is finely adjusted by an electric push rod to ensure that the angle between the spray angle and the normal of the workpiece surface is controlled within 5°. For different nozzle models, the spraying parameters are calibrated offline: for example, a 1mm diameter circular nozzle corresponds to a flow rate of 8L / min at a pressure of 2MPa, and a 60° fan-shaped nozzle corresponds to a flow rate of 12L / min at a pressure of 1.5MPa. A mapping table of "nozzle model-pressure-flow rate" is established and stored in the control system. Before processing, the corresponding parameters are called through the control system. At the start, the nozzle is pre-sprayed at 50% of the rated pressure for 3 seconds to remove air bubbles, and then the working parameters are switched to ensure stable initial spraying.

[0028] The position adjustment component employs a four-axis linkage robotic arm, with a nozzle fixture mounted at the end of the arm. It monitors the contact force between the nozzle and the workpiece in real time, scanning the workpiece's 3D contour (point cloud accuracy 0.01mm) using a vision sensor. The control system automatically generates the nozzle motion path based on the contour data: for planar workpieces, an "S"-shaped reciprocating path is used (row spacing is 80% of the nozzle spray width to avoid missed areas); for curved workpieces, a constant arc length spiral path is used (the feed per revolution is dynamically adjusted according to the radius of curvature, decreasing the feed for areas with greater curvature). The distance between the nozzle and the workpiece surface (working distance) is set. The robotic arm motion controller and the spray control system communicate via an EtherCAT bus (communication delay ≤1ms) to achieve "motion-spray" synchronization: when the robotic arm reaches the polishing position, a spray signal is triggered; when it leaves, the spray is turned off to avoid wasting polishing fluid through empty spraying.

[0029] The multi-dimensional detection module includes a vision sensor, a Coriolis flow meter, and a MEMS pressure sensor; the vision sensor acquires the relative position of the nozzle and the workpiece in real time; the Coriolis flow meter and the MEMS pressure sensor acquire the actual flow rate and pressure in the pipeline, respectively. The steps for the vision sensor to acquire the relative position between the nozzle and the workpiece are as follows: Fix the industrial vision sensor to the side of the robotic arm, with the lens axis at a 45° angle to the nozzle spray direction, to ensure that the field of view covers the nozzle tip and the workpiece area to be polished. A checkerboard calibration plate (accuracy 0.01mm) was attached to the surface of the workpiece, and 10 sets of calibration images at different positions were collected. The transformation matrix between the sensor coordinate system and the robot arm coordinate system was calculated using the Zhang Zhengyou calibration method (error ≤ 0.02mm), and the coordinate association was established. After the system starts, the vision sensor continuously acquires images at a frequency of 50ms / frame and transmits them to the control system in real time through the industrial camera SDK. An adaptive threshold segmentation algorithm is used to remove background interference and extract the contour features of the nozzle tip (preset as a circular feature with a known diameter) and the workpiece edge. Based on the calibrated coordinate transformation matrix, the coordinates of the nozzle center (x1, y1, z1) and the coordinates of the workpiece polishing point (x2, y2, z2) in the image are transformed to the same robotic arm coordinate system; The relative position deviation is calculated based on the nozzle center coordinates and the workpiece polishing point coordinates. The deviation data is then sent to the position adjustment component for dynamic correction of the nozzle position.

[0030] The steps for collecting the actual flow rate of a pipeline using a Coriolis flow meter are as follows: Connect the high-precision miniature Coriolis flow meter in series in the pipeline before the nozzle inlet, with the flow meter axis coaxial with the pipeline axis to avoid measurement errors caused by fluid disturbance; After the system is powered on, the flow meter performs a self-test (lasts 2 seconds) and sends the initialization status (normal / fault) to the control system through the 485 communication interface. An alarm is triggered when a fault occurs. The flow meter has a built-in vibration sensor that detects the phase difference in the pipe body caused by the Coriolis force generated during fluid flow and outputs the raw flow signal in real time. After the signal is digitized by the internal AD converter (sampling rate 1MHz) of the flow meter, the high-frequency noise caused by pump vibration is removed by digital filtering (Butterworth low-pass filter, cutoff frequency 1kHz) to obtain the instantaneous flow value. The control system receives an instantaneous flow rate value every 5ms, continuously collects 10 data points, performs a moving average process, and obtains a stable flow rate value. When the flow rate exceeds the preset range, the flow meter outputs an abnormal signal, triggering the delivery module to adjust the parameters.

[0031] The steps for the MEMS pressure sensor to acquire the actual pressure of the pipeline are as follows: Install the MEMS pressure sensor into the side hole of the nozzle inlet pipeline through the threaded interface, with the sensor sensitive surface perpendicular to the fluid direction to ensure that the pressure transmission is lag-free; By applying pressure at five points (0, 2, 5, 8, and 10 MPa) using a standard pressure source, the sensor output voltage values ​​were recorded, and a pressure-voltage conversion curve was obtained through fitting. The sensor detects the fluid pressure in the pipeline in real time, converts the pressure signal into a 0-5V analog voltage signal, and transmits it to the AD acquisition card of the control system after passing through the signal conditioning circuit (amplified 10 times and filtered). The collected pressure signal is subjected to spectrum analysis to extract the fundamental frequency and harmonic components of the pump body pulsation (to verify the cancellation effect of the pulsation attenuation module), and the average pressure value within 100ms is calculated. The control system compares the average pressure value P with the target pressure P and calculates the deviation ΔP. When the absolute value of ΔP is greater than 0.05 MPa, it sends a pressure adjustment command to the delivery module.

[0032] The modeling and prediction module calculates pipeline resistance based on the relative position of the nozzle and the workpiece using fluid dynamics equations, and predicts pulsation by decomposing the pump body pulsation law using Fourier transform. The resistance is dynamically calculated by correlating pipeline head loss with nozzle position using fluid dynamics equations, and predicted by decomposing pump body pulsation using Fourier transform. Define pipeline structure parameters, including total pipeline length L (which varies with nozzle position z, and L increases as z increases), pipe diameter d (fixed value), and local resistance coefficients of local resistance components (such as elbows and valves). The real-time three-dimensional coordinates of the nozzle are collected by a vision sensor, and the actual length of the pipeline is calculated by adding the initial fixed length of the pipeline to the deviation value of the vertical coordinate. The head loss along the pipeline and the local head loss are calculated based on the Darcy-Weisbach formula. The total head loss of the pipeline is the sum of the head loss along the pipeline and the local head loss. The original signal of pump outlet pressure pulsation is acquired by MEMS pressure sensor, the original signal is preprocessed, the preprocessed signal is subjected to fast Fourier transform to obtain frequency domain signal, the main frequency components are extracted from the frequency domain signal, the fundamental frequency and harmonic frequency of pump body pulsation are identified by spectrum analysis, and the amplitude and phase of each frequency component are recorded. Based on the results of Fast Fourier Transform decomposition, a time-domain prediction model for pulsation is established to predict pulsations.

[0033] The dynamic control module uses a reverse current control attenuator to counteract pulsation by predicting pulsation output. Combined with preset target flow and pressure, it adjusts the pump's displacement and speed in real time using a fuzzy PID algorithm.

[0034] First, the pump body pulsation prediction value output by the modeling and prediction module is received. The proportional-integral control algorithm is used to calculate the reverse compensation current, which is inversely related to the predicted pulsation and is used to drive the annular electromagnet of the magnetorheological pulsation attenuator. The ring electromagnet generates a corresponding magnetic field strength based on the received reverse compensation current, changes the apparent viscosity of the internal magnetorheological fluid, and forms variable damping. When the predicted pulsation is a positive peak, the damping increases, and when it is a negative peak, the damping decreases, thus actively counteracting the pump body pressure fluctuation. At the same time, the module receives the preset target flow rate and target pressure from the workpiece adaptive matching module. The target pressure needs to be corrected in combination with the total head loss of the pipeline calculated by the modeling and prediction module. The actual flow rate and actual pressure in the pipeline are collected by Coriolis flow meter and MEMS pressure sensor, respectively, and the deviation between the actual value and the target value and the integral of the deviation are calculated. Based on the fuzzy PID algorithm, the proportional coefficient and integral coefficient are dynamically adjusted according to the flow deviation and the integral of the deviation to output the pump's displacement adjustment amount. The displacement correction is achieved by changing the swashplate angle of the servo variable pump. Similarly, the output pump speed is adjusted by dynamically adjusting the corresponding proportional coefficient and integral coefficient based on the pressure deviation and the integral of the deviation, and the pressure correction is achieved by changing the speed of the drive motor.

[0035] To address the coupling effect between displacement and speed regulation, an offline-calibrated decoupling coefficient is introduced to cross-correct the displacement and speed regulation values, thus avoiding mutual interference.

[0036] The system collects real-time data on the actual pulsation at the attenuator outlet, as well as the actual flow and pressure data in the pipeline. It continuously calculates control errors and dynamically corrects the reverse compensation current and the pump's displacement and speed adjustment parameters to ensure pulsation cancellation effect and injection parameter stability.

[0037] Example 2, Figure 2 This invention provides a method for supplying magnetorheological polishing fluid based on jetting technology.

[0038] A method for supplying magnetorheological polishing slurry based on jetting technology includes the following steps: The relative position of the nozzle and the workpiece is acquired by a vision sensor, and the flow rate and pressure in the pipeline are acquired by a Coriolis force flow meter and a MEMS pressure sensor, respectively. The pipeline resistance is calculated based on the relative position of the nozzle and the workpiece, and the pulsation is predicted by decomposing the pump body pulsation law through Fourier transform. The pulsation is counteracted by a reverse current control attenuator based on the pulsation prediction output. Combined with preset target flow and pressure, the pump's displacement and speed are adjusted in real time using a fuzzy PID algorithm.

[0039] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0040] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0041] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0042] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0043] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0044] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A magnetorheological polishing slurry supply system based on jetting technology, characterized in that, It includes a liquid storage and delivery module, a pulsation attenuation module, a jet execution module, a multi-dimensional detection module, a modeling and prediction module, and a dynamic control module. The modules are interconnected. A liquid storage and delivery module includes a liquid storage device and a delivery device. The liquid storage device is used to store magnetorheological polishing liquid, and the delivery device provides power for delivering the magnetorheological polishing liquid. The pulsation attenuation module is equipped with a magnetorheological pulsation attenuator connected in series between the outlet of the servo variable pump and the delivery pipeline. The spraying execution module includes a nozzle and a position adjustment component. The nozzle is used to directionally spray magnetorheological polishing fluid onto the surface of the workpiece to be polished. The position adjustment component drives the nozzle to move. The multi-dimensional detection module includes a vision sensor, a Coriolis flow meter, and a MEMS pressure sensor; the vision sensor acquires the relative position of the nozzle and the workpiece; the Coriolis flow meter and the MEMS pressure sensor acquire the pipeline flow rate and pressure, respectively; The modeling and prediction module calculates the pipeline resistance based on the relative position of the nozzle and the workpiece, and predicts the pulsation by decomposing the pump body pulsation law through Fourier transform. The dynamic control module uses a reverse current control attenuator to counteract pulsation by predicting pulsation output. Combined with preset target flow and pressure, it adjusts the pump's displacement and speed in real time using a fuzzy PID algorithm.

2. The magnetorheological polishing slurry supply system based on jetting technology according to claim 1, characterized in that, The conveying device includes a servo variable pump, which changes the output flow rate and pressure by adjusting the displacement and motor speed.

3. The magnetorheological polishing slurry supply system based on jetting technology according to claim 2, characterized in that, The magnetorheological pulsation attenuator consists of a ring electromagnet and a magnetorheological fluid chamber. The ring electromagnet adjusts the magnetic field strength by receiving a control current, thereby changing the viscosity of the magnetorheological fluid inside the magnetorheological fluid chamber and forming variable damping to counteract pump body pulsation.

4. The magnetorheological polishing slurry supply system based on jetting technology according to claim 3, characterized in that, The position adjustment component drives the nozzle movement as follows: The position adjustment component uses a four-axis linkage robotic arm with a nozzle fixture installed at the end of the robotic arm. It monitors the contact force between the nozzle and the workpiece in real time and scans the three-dimensional contour of the workpiece through a vision sensor. The control system automatically generates the nozzle motion path based on the contour data: for planar workpieces, an S-shaped reciprocating path is used; for curved workpieces, a spiral path with equal arc length is used. The robotic arm motion controller and the spray control system communicate via EtherCAT bus. When the robotic arm reaches the position to be polished, the spray signal is triggered; when it leaves, the spray is turned off to avoid wasting polishing fluid by spraying dry.

5. The magnetorheological polishing slurry supply system based on jetting technology according to claim 4, characterized in that, The steps for using the vision sensor to acquire the relative position of the nozzle and the workpiece are as follows: The industrial vision sensor is fixed to the side of the robotic arm, with the lens axis at a 45° angle to the nozzle spray direction; A checkerboard calibration plate is attached to the surface of the workpiece, calibration images at different positions are collected, and the transformation matrix between the sensor coordinate system and the robot arm coordinate system is calculated using the Zhang Zhengyou calibration method to establish coordinate association. After the system starts up, the vision sensor continuously acquires images and transmits them to the control system in real time through the industrial camera SDK. An adaptive threshold segmentation algorithm is used to remove background interference and extract the contour features of the nozzle tip and the workpiece edge. Based on the calibrated coordinate transformation matrix, the coordinates of the nozzle center and the workpiece polishing point in the image are transformed to the same robotic arm coordinate system; The relative position deviation is calculated based on the nozzle center coordinates and the workpiece polishing point coordinates. The deviation data is then sent to the position adjustment component for dynamic correction of the nozzle position.

6. The magnetorheological polishing slurry supply system based on jetting technology according to claim 5, characterized in that, The steps for collecting pipeline flow using a Coriolis flow meter are as follows: Connect the Coriolis flow meter in series in the pipeline before the nozzle inlet, with the flow meter axis coaxial with the pipeline axis; After the system is powered on, the flow meter performs a self-test and sends an initialization status to the control system through the communication interface; The flow meter has a built-in vibration sensor that detects the phase difference in the pipe body caused by the Coriolis force generated during fluid flow and outputs the raw flow signal in real time. After the signal is digitized by the internal AD converter of the flow meter, the high-frequency noise caused by pump vibration is removed by digital filtering to obtain the instantaneous flow value; The control system receives several instantaneous flow values ​​and performs a moving average to obtain a stable flow value.

7. The magnetorheological polishing slurry supply system based on jetting technology according to claim 6, characterized in that, The steps for using a MEMS pressure sensor to acquire pipeline pressure are as follows: The MEMS pressure sensor is installed in the side hole of the nozzle inlet pipe through a threaded interface, with the sensor's sensitive surface perpendicular to the fluid direction. Pressure is applied using a standard pressure source, the sensor output voltage value is recorded, and a pressure-voltage conversion curve is obtained by fitting the data. The sensor detects the fluid pressure in the pipeline in real time, converts the pressure signal into an analog voltage signal, and transmits it to the AD acquisition card of the control system after the signal conditioning circuit. The collected pressure signal is subjected to spectrum analysis to extract the fundamental frequency and harmonic components of the pump body pulsation, and the average pressure value is calculated at the same time. The control system compares the average pressure value with the target pressure and calculates the deviation ΔP. When the absolute value of ΔP is greater than 0.05 MPa, it sends a pressure adjustment command to the delivery module.

8. The magnetorheological polishing slurry supply system based on jetting technology according to claim 7, characterized in that, The modeling and prediction module is implemented as follows: Define pipeline structure parameters, collect real-time three-dimensional coordinates of nozzles, and calculate the actual length of pipeline based on the initial fixed length of pipeline; The head loss along the pipeline and the local head loss are calculated based on the Darcy-Weisbach formula. The total head loss of the pipeline is the sum of the head loss along the pipeline and the local head loss. The raw signal of pump outlet pressure pulsation is acquired by a MEMS pressure sensor, and the raw signal is preprocessed. The preprocessed signal is subjected to a fast Fourier transform to obtain a frequency domain signal, and the main frequency components are extracted from the frequency domain signal. The fundamental frequency and harmonic frequencies of pump body pulsation are identified by spectrum analysis, and the amplitude and phase of each frequency component are recorded. Based on the results of Fast Fourier Transform decomposition, a time-domain prediction model for pulsation is established to predict pulsations.

9. A magnetorheological polishing slurry supply system based on jetting technology according to claim 8, characterized in that, The implementation process of the dynamic control module is as follows: The reverse compensation current is calculated using a proportional-integral control algorithm based on the predicted value of pump body pulsation. The ring electromagnet generates a corresponding magnetic field strength based on the received reverse compensation current, changes the apparent viscosity of the internal magnetorheological fluid, and forms variable damping. When the predicted pulsation is a positive peak, the damping increases, and when it is a negative peak, the damping decreases, thus actively counteracting the pump body pressure fluctuation. The actual flow rate and actual pressure in the pipeline are collected by Coriolis flow meter and MEMS pressure sensor respectively. The deviation between the actual value and the target value and the integral of the deviation are calculated by combining the preset target flow rate and target pressure. Based on the fuzzy PID algorithm, the proportional coefficient and integral coefficient are dynamically adjusted according to the flow deviation and the integral of the deviation to adjust the output pump displacement. The displacement correction is achieved by changing the swashplate angle of the servo variable pump. Similarly, based on the pressure deviation and the integral of the deviation, the corresponding proportional coefficient and integral coefficient are dynamically adjusted to adjust the speed of the output pump, and the pressure correction is achieved by changing the speed of the drive motor. To address the coupling effect between displacement and speed regulation, an offline-calibrated decoupling coefficient is introduced to cross-correct the displacement and speed regulation values. The system collects real-time data on the actual pulsation at the attenuator outlet, as well as the actual flow and pressure data in the pipeline. It continuously calculates control errors and dynamically corrects the reverse compensation current and the pump's displacement and speed adjustment parameters.

10. A method for supplying magnetorheological polishing slurry based on jetting technology according to claim 9, characterized in that, Includes the following steps: The relative position of the nozzle and the workpiece is acquired by a vision sensor, and the flow rate and pressure in the pipeline are acquired by a Coriolis force flow meter and a MEMS pressure sensor, respectively. The pipeline resistance is calculated based on the relative position of the nozzle and the workpiece, and the pulsation is predicted by decomposing the pump body pulsation law through Fourier transform. The pulsation is counteracted by a reverse current control attenuator based on the pulsation prediction output. Combined with preset target flow and pressure, the pump's displacement and speed are adjusted in real time using a fuzzy PID algorithm.

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