Closed-loop system and method for suppressing vibration of grinding spindle through magnetic damping

Abstract

The invention relates to the technical field of grinding systems, discloses a closed-loop system and method for suppressing vibration of a grinding spindle through magnetic damping, and aims to solve the problems of how to better suppress the vibration of the grinding spindle and improve the machining quality. The closed-loop system comprises a grinding spindle, a sensing module, a magnetic field execution module and a controller. The sensing module is used for detecting the temperature value of the grinding spindle. The magnetic field execution module is used for generating a damping magnetic field to restrain vibration of the grinding spindle. The sensing module and the magnetic field execution module are electrically connected with the controller, and the controller is configured to obtain the optimal value of the magnetic induction intensity of the magnetic field execution module; the temperature value of the grinding spindle at the current moment is obtained, the temperature change rate at the current moment is calculated, and the predicted temperature value after the preset time is predicted; and if the predicted temperature value is greater than or equal to the safe temperature threshold value and / or the temperature change rate is greater than or equal to the early warning rate, controlling the magnetic induction intensity of the magnetic field execution module to be less than the optimal value.

Description

Technical Field

[0001] This application relates to the field of grinding equipment technology, and in particular to a closed-loop system and method for suppressing grinding spindle vibration by magnetostriction. Background Technology

[0002] In ultra-precision grinding, the grinding spindle of the grinding equipment will vibrate during rotation. The vibration of the grinding spindle will affect the surface quality (such as roughness, waviness, etc.) and shape accuracy of the workpiece. Therefore, components to suppress the vibration of the grinding spindle are usually installed in the grinding equipment.

[0003] In existing technologies, magnetic components such as electromagnets that can generate magnetic field damping are installed in grinding equipment to suppress the vibration of the grinding spindle. However, the magnetic field applied to the grinding spindle by the magnetic components will generate eddy currents within the grinding spindle (especially grinding spindles supported by conductive / magnetic materials), leading to excessively high temperatures and deformation of the grinding spindle. This, in turn, will cause the grinding spindle to vibrate, affecting the machining quality of the workpiece. Summary of the Invention

[0004] The purpose of this application is to provide a closed-loop system and method for suppressing grinding spindle vibration with magnetostrictive damping, aiming to solve the problem of how to better suppress the vibration of grinding spindle and improve machining quality.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] In a first aspect, this application provides a closed-loop system for suppressing the vibration of a grinding spindle using magnetostrictive damping. The closed-loop system includes a grinding spindle, a sensing module, a magnetic field execution module, and a controller. The sensing module is used to detect the temperature value of the grinding spindle; the magnetic field execution module is used to generate a damping magnetic field to suppress the vibration of the grinding spindle; both the sensing module and the magnetic field execution module are electrically connected to the controller, which is configured to: Obtain the optimal value of the magnetic induction intensity of the magnetic field actuation module. The optimal value is used to suppress the vibration of the grinding spindle to the greatest extent. Obtain the temperature value of the grinding spindle at the current moment, and calculate the temperature change rate at the current moment based on the current temperature value, as well as the predicted temperature value after a preset time. If the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, then the magnetic induction intensity of the control magnetic field execution module is the optimal value. If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then the magnetic induction intensity of the control magnetic field execution module is less than the optimal value.

[0007] The closed-loop system for suppressing grinding spindle vibration by magnetostriction provided in this application can accurately determine the temperature change trend of the grinding spindle at the current moment by calculating the temperature change rate at the current moment. Furthermore, by predicting the temperature change value of the grinding spindle after a preset time, it can predict in advance whether the temperature of the grinding spindle will exceed the safe temperature threshold after the preset time. Thus, if the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, the magnetic induction intensity of the control magnetic field execution module is set to the optimal value. This can suppress the vibration of the grinding spindle to the greatest extent and avoid the grinding spindle from overheating and deforming, thereby ensuring the processing quality of the workpiece. Furthermore, when the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, it indicates that the grinding spindle temperature is trending towards exceeding the safe temperature threshold, or that the grinding spindle temperature may exceed the safe temperature threshold after a preset time. In this case, the magnetic induction intensity of the control magnetic field actuator is less than the optimal value, which can reduce the rate at which the grinding spindle's temperature rises due to the damping magnetic field applied by the magnetic field actuator in advance. This allows for timely temperature control of the grinding spindle, preventing overheating and deformation, and ensuring the machining quality of the workpiece. In addition, by predicting the grinding spindle temperature trend in advance, it is also possible to prevent the grinding spindle from exceeding the safe temperature threshold and causing it to stop, thus ensuring continuous operation and improving work efficiency.

[0008] In some embodiments, the controller is further configured to: A first-order discrete model is used to predict the temperature rise over a preset time period after the current moment. The predicted temperature value is calculated based on the temperature rise value after a preset time.

[0009] In some embodiments, the controller is further configured to: The predicted temperature value after a preset time following the current moment is calculated using the following formula:

[0010]

[0011] in, It is a correction function related to the rotational speed of the grinding spindle. , This refers to the rotational speed of the grinding spindle. This is the reference speed for the grinding spindle; The temperature rise value within a preset time period. This is the predicted temperature value after a preset time. The rate of temperature change at the current moment. This represents the optimal value for the magnetic field strength of the magnetic field actuator module. For model parameters, The heating rate of the grinding spindle is caused by heat other than that generated by magnetic field eddy currents. The duration of the preset time period.

[0012] In some embodiments, the controller is further configured to: If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then with the goal of suppressing vibration and the constraint that the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, the suboptimal value of the magnetic induction intensity of the magnetic field execution module is calculated, and the suboptimal value is less than the optimal value. The magnetic induction intensity of the control magnetic field execution module is a suboptimal value.

[0013] In some embodiments, the sensing module is also used to detect the actual vibration value of the grinding spindle; The controller is also configured as follows: The target vibration value of the grinding spindle is obtained, and the error between the actual vibration value detected by the sensing module and the target vibration value is calculated. The magnetic induction intensity of the magnetic field execution module is calculated by a control algorithm to minimize errors, thereby obtaining the optimal value.

[0014] In some embodiments, the controller is further configured to: The optimal value is calculated using the following formula:

[0015] in, For error, , This represents the actual vibration value. For the target vibration value, , , All are coefficients. This represents the optimal value of the magnetic induction intensity for the magnetic field execution module.

[0016] In some embodiments, the controller is further configured to: Establish or identify an approximate transfer function model G(s) of “magnetic induction intensity B → principal shaft vibration response V”; The optimal value is calculated using the following formula:

[0017] in, This is the feedforward term of the inverse model, used to cancel out known disturbances; This is a feedback term used to correct model errors and unknown disturbances. This represents the optimal value of the magnetic induction intensity for the magnetic field execution module.

[0018] In some embodiments, the controller includes a filter, and the controller is further configured to: The optimal value is calculated using the following formula:

[0019] in, Let be the transfer function of the filter. This is the reference input signal for the filter. This represents the optimal value for the magnetic field strength of the magnetic field actuator module. It indicates a direct proportional relationship.

[0020] In some embodiments, the sensing module includes a vibration detection device and a temperature detection device, wherein the vibration detection device is used to detect the actual vibration value of the grinding spindle, and the temperature detection device is used to detect the temperature value of the grinding spindle. And / or, the magnetic field actuation module includes an electromagnet and a drive power supply. Along the radial direction of the grinding spindle, the electromagnet is located on one side of the grinding spindle and is used to apply a damped magnetic field to the grinding spindle. The drive power supply is electrically connected to the electromagnet and is used to control the magnetic induction intensity of the electromagnet.

[0021] Secondly, this application also provides a method for suppressing grinding spindle vibration using magnetostrictive damping, the method comprising: To obtain the optimal value of the magnetic induction intensity applied to the grinding spindle, the optimal value is used to suppress the vibration of the grinding spindle to the greatest extent; Obtain the temperature value of the grinding spindle at the current moment, and calculate the temperature change rate at the current moment based on the current temperature value, as well as the predicted temperature value after a preset time. If the predicted temperature is less than the safe temperature threshold and the rate of temperature change is less than the warning rate, then the magnetic induction intensity applied to the grinding spindle is the optimal value. If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then the magnetic induction intensity applied to the grinding spindle is less than the optimal value. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a closed-loop system for suppressing grinding spindle vibration using magnetostrictive damping, as shown in an embodiment of this application. Figure 2 for Figure 1 The diagram shows a closed-loop system without the drive power supply. Figure 3 A schematic diagram showing the relationship between the components in a closed-loop system for suppressing grinding spindle vibration using magnetostrictive damping, as provided in an embodiment of this application. Figure 4 A schematic flowchart illustrating a method for suppressing grinding spindle vibration using magnetostrictive damping, provided in an embodiment of this application; Figure 5 This is a complete flowchart illustrating a method for suppressing grinding spindle vibration using magnetostrictive damping, as provided in an embodiment of this application.

[0024] Figure label: 1. Grinding equipment; 11. Base; 12. Drive components; 13. Grinding spindle; 14. Grinding wheel; 2. Vibration suppression device; 21. Sensing module; 211. Temperature detection device; 212. Vibration detection device; 22. Magnetic field actuation module; 221. Electromagnet; 222. Drive power supply; 23. Controller. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0028] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram illustrating the structure of a closed-loop system for suppressing grinding spindle vibration using magnetostrictive damping, as shown in an embodiment of this application. Figure 2 for Figure 1 The diagram shows a closed-loop system without a drive power supply. This application provides a closed-loop system for suppressing grinding spindle vibration using magnetostrictive damping. The closed-loop system also includes a grinding device 1, which is used for precision grinding of a workpiece. The workpiece can be sheet metal, a shaft, etc., and this application does not specifically limit its application.

[0029] In some embodiments, please continue reading Figure 1 and Figure 2 The grinding equipment 1 may include a base 11, a drive component 12, a grinding spindle 13, and a grinding wheel 14. The drive component 12 is connected to the base 11, which supports the drive component 12. The drive component 12 is connected to the grinding spindle 13 and drives the grinding spindle 13 to rotate. The grinding wheel 14 is connected to the grinding spindle 13, and the rotation of the grinding spindle 13 drives the grinding wheel 14 to rotate, thereby grinding the workpiece. For example, the drive component 12 may be a rotary motor or other components capable of driving the grinding spindle 13 to rotate; this application does not specifically limit this.

[0030] The aforementioned grinding equipment 1 can perform ultra-precision grinding on workpieces. Ultra-precision grinding requires high machining accuracy. However, the grinding spindle 13 of the grinding equipment 1 vibrates during rotation, which affects the surface quality (e.g., roughness, waviness, etc.) and shape accuracy of the workpiece, thus affecting the machining accuracy. Therefore, in some embodiments, please refer to... Figure 1 , Figure 2 and Figure 3 , Figure 3 This is a schematic diagram showing the relationship between the components in a closed-loop system for suppressing vibration of a grinding spindle 13 using magnetostrictive damping, as provided in an embodiment of this application. The closed-loop system may further include a vibration suppression device 2, which is used to suppress the vibration of the grinding spindle 13 of the grinding equipment 1, so as to ensure the smooth rotation of the grinding spindle 13 and thereby improve the grinding quality of the workpiece.

[0031] In some related technologies, vibration suppression devices 2 are typically passive vibration isolation devices, such as those using vibration isolation pads, active balancing, and active control based on actuators (such as piezoelectric ceramics, voice coil motors, etc.). These methods have limited effectiveness in suppressing low-frequency vibrations, are structurally complex, have poor vibration suppression performance, and are inconvenient to operate.

[0032] Based on this, in some other related technologies, the vibration suppression device 2 can be a magnetic component of an electromagnet. The magnetic field generated by the magnetic component produces magnetic field damping on the grinding spindle 13, thereby suppressing the vibration of the grinding spindle 13 through magnetic field damping. This method is a non-contact vibration suppression method with a simple structure and good vibration suppression effect.

[0033] However, the magnetic field applied to the grinding spindle 13 by the magnetic components will generate eddy currents in the grinding spindle 13 (especially the grinding spindle 13 supported by conductive / magnetic materials), which will cause the grinding spindle 13 to overheat and deform. As a result, the grinding spindle 13 will also vibrate, which will affect the processing quality of the workpiece.

[0034] Based on this, the vibration suppression device 2 provided in this application, in addition to suppressing the vibration of the grinding spindle 13 by magnetic field damping, adds the detection and related control of the temperature of the grinding spindle 13, thereby avoiding deformation of the grinding spindle 13 due to excessive temperature, so as to further improve the processing quality of the workpiece.

[0035] In some embodiments, please refer to Figure 1 , Figure 2 and Figure 3 The vibration suppression device 2 provided in this application may include a sensing module 21, a magnetic field actuation module 22, and a controller 23. The sensing module 21 is used to detect the temperature value of the grinding spindle 13, so as to control it in time when the temperature value is too high, thereby preventing the grinding spindle 13 from deforming due to excessive temperature. For example, the sensing module 21 may include a temperature detection device 211, which is used to detect the temperature value of the grinding spindle 13. For example, the temperature detection device 211 can be an infrared temperature sensor to detect the temperature of the grinding spindle 13 in a non-contact manner, thus facilitating the detection of the grinding spindle 13's temperature. Alternatively, the temperature detection device 211 can also be a wireless embedded temperature sensor, which allows the temperature sensor to be directly placed on the grinding spindle 13 and data to be transmitted wirelessly, also facilitating the detection of the grinding spindle 13's temperature.

[0036] The magnetic field actuation module 22 is used to generate a damping magnetic field to suppress the vibration of the grinding spindle 13. In some embodiments, the magnetic field actuation module 22 may include an electromagnet 221 and a drive power supply 222. The drive power supply 222 is electrically connected to the electromagnet 221 and is used to energize the electromagnet 221 so that the electromagnet 221 generates a damping magnetic field. The damping magnetic field acts on the grinding spindle 13 to suppress the vibration of the grinding spindle 13. Furthermore, the drive power supply 222 can also control the magnetic induction intensity of the electromagnet 221 by controlling the current to the electromagnet 221, thereby controlling the intensity of the damping magnetic field to adjust the damping effect on the grinding spindle 13.

[0037] In some examples, the drive power supply 222 can be a programmable DC power supply. In other examples, the drive power supply 222 can also be other power supplies that can input DC power to the electromagnet 221 and control the voltage and current; this application does not specifically limit this.

[0038] In some examples, the electromagnet 221 is positioned on one side of the grinding spindle 13 along its radial direction. This allows the electromagnet 221 to better apply a damping magnetic field to the grinding spindle 13, thus better suppressing its vibration. Furthermore, the electromagnet 221 does not contact the grinding spindle 13, facilitating the arrangement of both components and reducing the resistance to rotation of the grinding spindle 13, thereby improving the smoothness of its rotation.

[0039] In other embodiments, the magnetic field actuation module 22 may also include an electromagnetic coil and a power supply. By energizing the electromagnetic coil with the power supply, the electromagnetic coil can generate a damping magnetic field on the grinding spindle 13 to suppress the vibration of the grinding spindle 13.

[0040] Both the sensing module 21 and the magnetic field execution module 22 are electrically connected to the controller 23. The controller 23 is used to receive the temperature value detected by the sensing module and control the magnetic induction intensity generated by the magnetic field execution module 22 according to the temperature value, thereby controlling the intensity of the damping magnetic field generated by the magnetic field execution module 22 on the grinding spindle 13, so as to avoid the grinding spindle 13 from being deformed due to excessive magnetic field intensity. It is also used to control the magnetic field execution module 22 to suppress the vibration of the grinding spindle 13 to the greatest extent while ensuring the temperature of the grinding spindle 13.

[0041] In some examples, the temperature detection device 211 of the sensing module 21 and the drive power supply 222 of the magnetic field actuation module 22 are both electrically connected to the controller 23. The controller 23 is used to receive the temperature value detected by the temperature detection device 211 and to control the magnetic induction intensity of the electromagnet 221 by controlling the magnitude of the current input to the electromagnet 221 by the drive power supply 222.

[0042] In some examples, controller 23 is a smart controller.

[0043] In some embodiments, controller 23 is configured to: The optimal value of the magnetic induction intensity of the magnetic field execution module 22 is obtained, and the optimal value is used to suppress the vibration of the grinding spindle 13 to the greatest extent.

[0044] The temperature value of the grinding spindle 13 at the current moment is obtained, and the temperature change rate at the current moment is calculated based on the current temperature value, as well as the predicted temperature value after a preset time. It should be noted that the preset time can be fixed, meaning the prediction of the predicted temperature value of the grinding spindle 13 after the preset time is periodic. That is, the temperature of the grinding spindle 13 is predicted once every preset time interval. The preset time can be 30 seconds, 60 seconds, 90 seconds, 120 seconds, etc., and this application does not specifically limit it.

[0045] If the predicted temperature is lower than the safe temperature threshold and the temperature change rate is lower than the warning rate, then the magnetic induction intensity of the control magnetic field execution module 22 is at its optimal value. The safe temperature threshold can be 80℃, 90℃, 100℃, 120℃, 150℃, etc. The warning rate can be 3℃ / s, 4℃ / s, 5℃ / s, 6℃ / s, 8℃ / s, 10℃ / s, etc.

[0046] If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then the magnetic induction intensity of the control magnetic field execution module 22 is less than the optimal value. In other words, if the predicted temperature value is greater than or equal to the safe temperature threshold, it indicates that the grinding spindle 13 has a thermal risk, meaning the temperature of the grinding spindle 13 may cause it to overheat and deform. Alternatively, if the temperature change rate is greater than or equal to the warning rate, it indicates that the grinding spindle 13 has a thermal risk, meaning the temperature of the grinding spindle 13 may cause it to overheat and deform. Or, if the predicted temperature value is greater than or equal to the safe temperature threshold, and the temperature change rate is greater than or equal to the warning rate, it indicates that the grinding spindle 13 has a thermal risk, meaning the temperature of the grinding spindle 13 may cause it to overheat and deform.

[0047] In this way, by calculating the temperature change rate at the current moment, the temperature change trend of the grinding spindle 13 at the current moment can be judged relatively accurately. Furthermore, by predicting the temperature change value of the grinding spindle 13 after a preset time, it is possible to predict in advance whether the temperature of the grinding spindle 13 will exceed the safe temperature threshold after the preset time. Thus, if the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, the magnetic induction intensity of the control magnetic field execution module 22 is set to the optimal value. This can suppress the vibration of the grinding spindle 13 to the greatest extent and prevent the grinding spindle 13 from deforming due to excessive temperature, thereby ensuring the processing quality of the workpiece. Furthermore, when the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, it indicates that the temperature of the grinding spindle 13 is likely to exceed the safe temperature threshold, or that the temperature of the grinding spindle 13 may exceed the safe temperature threshold after a preset time. At this time, the magnetic induction intensity of the control magnetic field execution module 22 is less than the optimal value, which can reduce the rate at which the damping magnetic field applied by the magnetic field execution module 22 to the grinding spindle 13 causes the temperature of the grinding spindle 13 to rise, so as to control the temperature of the grinding spindle 13 in a timely manner, avoid the grinding spindle 13 from overheating and deforming, and ensure the processing quality of the workpiece. In addition, by judging the temperature trend of the grinding spindle 13 in advance, it is also possible to avoid the grinding spindle 13 from stopping due to the temperature exceeding the safe temperature threshold, so as to ensure the continuous operation of the grinding spindle 13 and improve work efficiency.

[0048] In some embodiments, the controller 23 is further configured to: A first-order discrete model is used to predict the temperature rise over a preset time period after the current moment. The predicted temperature value is calculated based on the temperature rise value after a preset time.

[0049] That is, the above steps performed by the controller 23 are used to predict the temperature value after a preset time based on the current temperature value.

[0050] The first-order discrete model is a mathematical model used to predict the temperature change of the grinding spindle 13. Based on a first-order difference equation, this model describes the temperature evolution of the grinding spindle 13 at discrete time points. By using the first-order discrete model, the predicted temperature of the grinding spindle 13 after a preset time can be predicted relatively accurately based on the current temperature value. This allows for a relatively accurate prediction of whether the temperature of the grinding spindle 13 is likely to exceed a warning value, facilitating timely and accurate control of the damping magnetic field strength of the magnetic field execution module 22. This prevents the grinding spindle 13 from overheating and deforming, ensuring the grinding quality of the workpiece.

[0051] In some embodiments, the first-order discrete model can calculate the predicted temperature value using an algorithm formula preset within the controller 23. Specifically, the controller 23 is further configured to calculate the predicted temperature value after a preset time interval following the current moment using the following formula:

[0052]

[0053] in, This is a correction function related to the rotational speed of the grinding spindle. Because eddy current losses are related to the frequency of change of the damping magnetic field (proportional to the rotational speed), this correction function can be simplified to... , This refers to the rotational speed of the grinding spindle. This is the reference speed of the grinding spindle. The temperature rise value within a preset time period. This is the predicted temperature value after a preset time. The rate of temperature change at the current moment. This is the optimal value for the magnetic induction intensity of the magnetic field execution module 22. As model parameters, they can be calibrated by applying damping magnetic fields of different intensities to the grinding spindle 13 and recording the temperature rise curves during the debugging of the grinding equipment 1. The heating rate is the rate of increase caused by heat other than that generated by magnetic field eddy currents in the grinding spindle, such as the rate of increase caused by the heat generated by friction between the grinding spindle 13 and the bearing. This heating rate can be obtained by experimental calibration when the grinding spindle 13 is idle without a damping magnetic field applied, or it can be regarded as a disturbance. The duration of the preset time period.

[0054] In some examples, the rate of temperature change at the current moment The calculation can be performed using methods such as the central difference method or the short difference method; this application does not impose any specific limitations on this method.

[0055] The above formula can be used to calculate the temperature rise of the grinding spindle 13 within a preset time period, and the predicted temperature of the grinding spindle 13 after the preset time can be calculated based on the temperature rise. This allows for a more accurate prediction of whether the temperature of the grinding spindle 13 is likely to exceed the warning value, so as to timely and accurately control the strength of the damping magnetic field of the magnetic field execution module 22.

[0056] In other embodiments, the predicted temperature value of the grinding spindle 13 after a preset time can also be calculated using a second-order discrete model, a state-space model, a neural network model, etc. This application does not make specific limitations on this.

[0057] When the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the rate of temperature change is greater than or equal to the warning rate, in order to maximize the suppression of vibration of the grinding spindle 13 by the damping magnetic field of the magnetic field damping module while reducing the temperature of the grinding spindle 13, in some embodiments, the controller 23 is further configured to: If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then with the goal of suppressing vibration and the constraint that the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, the suboptimal value of the magnetic induction intensity of the magnetic field execution module 22 is calculated, and the suboptimal value is less than the optimal value. The magnetic induction intensity of the control magnetic field execution module 22 is a suboptimal value.

[0058] In other words, when the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, the controller 23 calculates a suboptimal value for the magnetic induction intensity of the magnetic field execution module 22. This suboptimal value satisfies the following conditions: the temperature of the grinding spindle 13 is controlled such that the predicted temperature value is less than the safe temperature threshold, and the temperature change rate is less than the warning rate. Furthermore, the magnetic field execution module 22 applies a damping magnetic field to the grinding spindle 13 according to this suboptimal value, which can maximally suppress the vibration of the grinding spindle 13. This avoids deformation of the grinding spindle 13 due to excessive temperature and ensures minimal vibration, thereby guaranteeing the machining quality of the workpiece.

[0059] In some examples, the suboptimal value of the magnetic field strength of the magnetic field execution module 22 can be found using the following function:

[0060] in, The objective function value for vibration optimization is the index that needs to be adjusted to the minimum. When this index is minimized, the magnetic induction intensity value of the magnetic field execution module 22 is the suboptimal value. The magnetic induction intensity of the magnetic field execution module 22. magnetic induction intensity The vibration value below indicates the magnetic induction intensity of the grinding spindle 13. The vibration level under a damped magnetic field. The target vibration value of the grinding spindle 13 can be reflected by parameters such as vibration amplitude and vibration frequency. The target vibration value can be 0 or 0±2, and the unit is the unit of the corresponding parameter.

[0061] Specifically, under the constraints that the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, the magnetic induction intensity of the magnetic field execution module 22 is continuously adjusted according to the above function formula until... The minimum value is the suboptimal value of the magnetic induction intensity of the magnetic field execution module 22. The suboptimal value can be found using the gradient descent method or a direct online search, based on the aforementioned function formula.

[0062] Gradient descent is an iterative optimization algorithm that calculates the objective function value. The gradient (derivative) of the magnetic induction intensity B of the design variable magnetic field execution module 22 is calculated, and the value of B is gradually adjusted in the opposite direction of the gradient to gradually reduce the objective function value, eventually converging to a local optimum, thus obtaining a suboptimal value. This method is computationally efficient and suitable for real-time control applications.

[0063] Direct online search refers to search within the feasible domain. Internally, the magnetic induction intensity B value corresponding to different magnetic field execution modules 22 is directly calculated through discrete sampling or grid search. Value, then select to make Minimum value The value is used as the solution, thus obtaining the suboptimal solution. The maximum adjustable value of the magnetic induction intensity B of the magnetic field execution module 22.

[0064] In some embodiments, the sensing module 21 is further configured to detect the actual vibration value of the grinding spindle 13. In some examples, the sensing module 21 may also include a vibration detection device 212, which is configured to detect the actual vibration value of the grinding spindle 13. The actual vibration value can be represented by parameters such as vibration amplitude and vibration frequency. In some examples, the vibration detection device 212 may be a non-contact motion sensor such as an eddy current sensor or an acceleration sensor, etc., and this application does not specifically limit its application to this.

[0065] Controller 23 is also configured as follows: The target vibration value of the grinding spindle 13 is obtained, and the error between the actual vibration value detected by the sensing module 21 and the target vibration value is calculated.

[0066] The magnetic field strength of the magnetic field execution module 22 is calculated by the control algorithm to minimize the error, so as to obtain the optimal value.

[0067] The smaller the error, the closer the actual vibration value of the grinding spindle 13 is to the target vibration value, that is, the smaller the vibration of the grinding spindle 13. The optimal value of the magnetic induction intensity of the magnetic field execution module 22 is calculated by the control algorithm, so that the magnetic induction intensity of the magnetic field execution module 22 works at the optimal value. At this time, the damping magnetic field applied by the magnetic field execution module 22 to the grinding spindle 13 has the best suppression of the vibration of the grinding spindle 13, so that the actual vibration value of the grinding spindle 13 is closest to the target vibration value, that is, the error between the actual vibration value detected by the sensing module 21 and the target vibration value is minimized. In this way, the strength of the damping magnetic field of the magnetic field execution module 22 can be controlled more accurately, and the vibration of the grinding spindle 13 can be better suppressed.

[0068] In some embodiments, the magnetic induction intensity of the magnetic field execution module 22 is calculated by a control algorithm to minimize errors in order to obtain the optimal value, which can be achieved by an algorithm formula preset in the controller 23.

[0069] Specifically, in some examples, controller 23 is also configured to calculate the optimal value using the following formula:

[0070] in, For error, , This represents the actual vibration value. For the target vibration value, , , These are all coefficients, which can be obtained through experimental tuning or self-tuning algorithms. This is the optimal value for the magnetic induction intensity of the magnetic field execution module 22.

[0071] The above formula is the PID algorithm formula. This formula can accurately calculate the optimal value of the magnetic induction intensity of the magnetic field execution module 22, ensuring that the optimal value maximizes the suppression of the grinding spindle 13's vibration, thus better controlling its vibration. Furthermore, the formula is directly driven by the error between the actual vibration value detected by the sensing module 21 and the target vibration value. Its logic is clear, its response is rapid, and it can quickly obtain the optimal value, thereby quickly suppressing the vibration of the grinding spindle 13.

[0072] In other examples, controller 23 is also configured as follows: Establish or identify an approximate transfer function model G(s) for “magnetic induction intensity B → principal shaft vibration response V”.

[0073] The optimal value is calculated using the following formula:

[0074] in, This is the feedforward term of the inverse model, used to cancel out known disturbances; This is a feedback term used to correct model errors and unknown disturbances. This is the optimal value for the magnetic induction intensity of the magnetic field execution module 22.

[0075] The above formula is based on the model-based feedforward-feedback composite control algorithm. This formula can also accurately calculate the optimal value of the magnetic field induction intensity of the magnetic field execution module 22, ensuring that the optimal value maximizes the suppression of the grinding spindle 13's vibration, thus better suppressing the vibration of the grinding spindle 13. Furthermore, the above formula can provide relatively accurate preliminary control values.

[0076] In some other examples, the controller 23 includes a filter. For instance, the filter could be an adaptive filter.

[0077] Controller 23 is also configured as follows: The optimal value is calculated using the following formula:

[0078] in, Let be the transfer function of the filter, and let its weights be determined according to the error. The filter, which is updated in real time and is typically represented by a difference equation or the Z-domain, is used to estimate the periodic vibration components associated with the grinding spindle 13. The reference input signal for the filter can be, for example, a synchronization signal related to the dominant vibration frequency, such as the harmonic component of the rotational speed. This signal is used to provide periodic information about the vibration as the input to the filter. The optimal value for the magnetic induction intensity of the magnetic field execution module 22. It indicates a direct proportional relationship.

[0079] The above formula is the least mean square adaptive filtering algorithm. Based on this formula, the optimal value of the magnetic induction intensity of the magnetic field actuation module 22 can be calculated relatively accurately, ensuring that the optimal value maximizes the suppression of the grinding spindle 13's vibration, thus better suppressing the vibration of the grinding spindle 13. Furthermore, the above formula can automatically track and suppress periodic vibrations associated with the grinding spindle 13, demonstrating a high level of effectiveness in suppressing the vibration of the grinding spindle 13.

[0080] In some embodiments, please refer to Figure 4, Figure 4 This is a flowchart illustrating a method for suppressing vibration of a grinding spindle 13 using magnetostrictive damping, as provided in an embodiment of this application. This application also provides a method for suppressing vibration of a grinding spindle 13 using magnetostrictive damping, the method comprising: S1: Obtain the optimal value of the magnetic induction intensity applied to the grinding spindle 13. The optimal value is used to suppress the vibration of the grinding spindle 13 to the greatest extent. S2: Obtain the temperature value of the grinding spindle 13 at the current moment, and calculate the temperature change rate at the current moment based on the temperature value at the current moment, as well as the predicted temperature value after a preset time. S3: If the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, then the magnetic induction intensity applied to the grinding spindle 13 is the optimal value. S4: If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then the magnetic induction intensity applied to the grinding spindle 13 is less than the optimal value.

[0081] In this way, by calculating the current temperature change rate, the temperature change trend of the grinding spindle 13 can be accurately determined. Furthermore, by predicting the temperature change value of the grinding spindle 13 after a preset time, it can be predicted in advance whether the temperature of the grinding spindle 13 will exceed the safe temperature threshold. Thus, if the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, the magnetic induction intensity of the control magnetic field execution module 22 is set to the optimal value. This maximizes the suppression of vibration of the grinding spindle 13 and prevents it from overheating and deforming, ensuring the machining quality of the workpiece. Moreover, if the predicted temperature value is greater than or equal to the safe temperature threshold and / or the temperature change rate is greater than or equal to the warning rate, the damping magnetic field applied to the grinding spindle 13 by the magnetic field execution module 22 can be reduced in advance, causing the temperature of the grinding spindle 13 to increase. This facilitates timely temperature control of the grinding spindle 13, preventing overheating and deformation, and ensuring the machining quality of the workpiece. In addition, by predicting the temperature trend of the grinding spindle 13 in advance, it is possible to avoid the grinding spindle 13 from being stopped due to its temperature exceeding the safe temperature threshold, thus ensuring that the grinding spindle 13 continues to work and improving work efficiency.

[0082] In some embodiments, please refer to Figure 5 , Figure 5 This is a complete flowchart illustrating a method for suppressing vibration of a grinding spindle 13 using magnetostrictive damping, as provided in an embodiment of this application. The method includes: S10: Initialize the system, set the initial values ​​of control parameters, safety temperature threshold, and warning rate; S20: Real-time acquisition of temperature and vibration signals of the grinding spindle 13; S30: The acquired temperature and vibration signals are filtered and the temperature and actual vibration values ​​of the grinding spindle 13 are calculated. S40: Obtain the target vibration value of the grinding spindle 13 and calculate the error between the actual vibration value detected by the sensing module 21 and the target vibration value; S50: The magnetic field strength of the magnetic field execution module 22 is calculated by the control algorithm to minimize the error, so as to obtain the optimal value; S60: Calculate the temperature change rate at the current moment based on the current temperature value, and predict the temperature value after a preset time. S70: Determine whether the predicted temperature value is less than the safe temperature threshold and whether the temperature change rate is less than the warning rate. S80: If the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, then the magnetic induction intensity of the control magnetic field execution module 22 is the optimal value. S90: If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then calculate the suboptimal value of the magnetic induction intensity of the magnetic field execution module 22, and control the magnetic induction intensity of the magnetic field execution module 22 to be the suboptimal value.

[0083] The above are merely specific embodiments 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.

Claims

1. A closed-loop system for suppressing grinding spindle vibration using magnetostrictive damping, characterized in that, include: Grinding spindle; The sensing module is used to detect the temperature value of the grinding spindle; A magnetic field actuation module is used to generate a damping magnetic field to suppress the vibration of the grinding spindle; The controller, wherein both the sensing module and the magnetic field execution module are electrically connected to the controller, and the controller is configured to: Obtain the optimal value of the magnetic induction intensity of the magnetic field execution module, which is used to suppress the vibration of the grinding spindle to the greatest extent. The temperature value of the grinding spindle at the current moment is obtained, and the temperature change rate at the current moment is calculated based on the temperature value at the current moment, as well as the predicted temperature value after a preset time. If the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, then the magnetic induction intensity of the magnetic field execution module is controlled to be the optimal value. If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then the magnetic induction intensity of the magnetic field execution module is controlled to be less than the optimal value.

2. The closed-loop system according to claim 1, characterized in that, The controller is also configured to: A first-order discrete model is used to predict the temperature rise over a preset time period after the current moment. The predicted temperature value is calculated based on the temperature rise value after a preset time.

3. The closed-loop system according to claim 2, characterized in that, The controller is also configured to: The predicted temperature value after a preset time following the current moment is calculated using the following formula: in, It is a correction function related to the rotational speed of the grinding spindle. , The rotational speed of the grinding spindle. The reference rotational speed of the grinding spindle; The temperature rise value within a preset time period. This is the predicted temperature value after a preset time. The rate of temperature change at the current moment. This represents the optimal value of the magnetic induction intensity of the magnetic field execution module. For model parameters, The heating rate of the grinding spindle is caused by heat other than that generated by the magnetic field eddy currents. The duration of the preset time period.

4. The closed-loop system according to any one of claims 1-3, characterized in that, The controller is also configured to: If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then with the goal of suppressing vibration and with the constraints that the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, the suboptimal value of the magnetic induction intensity of the magnetic field execution module is calculated, and the suboptimal value is less than the optimal value. The magnetic induction intensity of the magnetic field execution module is controlled to the suboptimal value.

5. The closed-loop system according to any one of claims 1-3, characterized in that, The sensing module is also used to detect the actual vibration value of the grinding spindle; The controller is also configured to: The target vibration value of the grinding spindle is obtained, and the error between the actual vibration value detected by the sensing module and the target vibration value is calculated. The optimal value is obtained by calculating the magnetic induction intensity of the magnetic field execution module to minimize the error through a control algorithm.

6. The closed-loop system according to claim 5, characterized in that, The controller is also configured to: The optimal value is calculated using the following formula: in, The error is... , The actual vibration value, The target vibration value, , , All are coefficients. This is the optimal value of the magnetic induction intensity of the magnetic field execution module.

7. The closed-loop system according to claim 5, characterized in that, The controller is also configured to: Establish or identify an approximate transfer function model G(s) of "magnetic induction intensity B → principal shaft vibration response V"; The optimal value is calculated using the following formula: in, This is the feedforward term of the inverse model, used to cancel out known disturbances; This is a feedback term used to correct model errors and unknown disturbances. This is the optimal value of the magnetic induction intensity of the magnetic field execution module.

8. The closed-loop system according to claim 5, characterized in that, The controller includes a filter and is further configured to: The optimal value is calculated using the following formula: in, Let be the transfer function of the filter. The reference input signal for the filter is... This represents the optimal value of the magnetic induction intensity of the magnetic field execution module. It indicates a direct proportional relationship.

9. The closed-loop system according to claim 5, characterized in that, The sensing module includes a vibration detection device and a temperature detection device. The vibration detection device is used to detect the actual vibration value of the grinding spindle, and the temperature detection device is used to detect the temperature value of the grinding spindle. And / or, the magnetic field execution module includes an electromagnet and a drive power supply. Along the radial direction of the grinding spindle, the electromagnet is disposed on one side of the grinding spindle and is used to apply a damped magnetic field to the grinding spindle. The drive power supply is electrically connected to the electromagnet and is used to control the magnetic induction intensity of the electromagnet.

10. A method for suppressing grinding spindle vibration using magnetostrictive damping, characterized in that, include: Obtain the optimal value of the magnetic induction intensity applied to the grinding spindle, the optimal value being used to suppress the vibration of the grinding spindle to the greatest extent; The temperature value of the grinding spindle at the current moment is obtained, and the temperature change rate at the current moment is calculated based on the temperature value at the current moment, as well as the predicted temperature value after a preset time. If the predicted temperature value is less than the safe temperature threshold and the temperature change rate is less than the warning rate, then the magnetic induction intensity applied to the grinding spindle is the optimal value. If the predicted temperature value is greater than or equal to the safe temperature threshold, and / or the temperature change rate is greater than or equal to the warning rate, then the magnetic induction intensity applied to the grinding spindle is less than the optimal value.

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