CN-122025341-A - High-frequency linear electromagnet and control method thereof

CN122025341ACN 122025341 ACN122025341 ACN 122025341ACN-122025341-A

Abstract

The invention discloses a high-frequency linear electromagnet and a control method thereof, which relate to the technical field of electromagnetic control, wherein the electromagnet comprises permanent magnet steel, a magnetizer, a magnet yoke, a motion shaft, an armature, a control coil and an elastic piece, wherein the magnetizer and the armature form four groups of uniform air gaps, an air gap magnetic field is changed after the coil is electrified to generate electromagnetic actuating force to drive the motion shaft to move until the electromagnetic actuating force is balanced with the restoring force and the load force of the elastic piece, the control method comprises the steps of front verification, magnetic field state sensing, dual-mode driving adjustment, dynamic error feedforward compensation, stability verification and self-adaptive parameter updating, and the intelligent switching of a quick response and a high-linearity mode is adopted to combine error compensation and parameter self-adaptive updating to counteract interference such as hysteresis, temperature and the like.

Inventors

FANG PING
FANG WENDA
GAO SHAN

Assignees

杭州科迅印刷设备有限公司
杭州正乾机电有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (10)

1. The high-frequency linear electromagnet is characterized by comprising permanent magnetic steel, a magnetizer, a magnetic yoke, a moving shaft, an armature, a control coil and an elastic piece, wherein the permanent magnetic steel and the magnetic yoke are both positioned on one side of the magnetizer, a magnetic force space is arranged in the magnetizer, the armature is positioned in the magnetic force space, an air gap is arranged between the armature and the magnetizer, the control coil is wound on the armature, the moving shaft vertically passes through the armature and is fixedly connected with the armature, and the elastic piece is positioned at one end of the moving shaft; When the control coil is electrified, the air gap magnetic field between the armature and the magnetizer is changed to generate electromagnetic actuating force to drive the motion shaft to move, and when the electromagnetic actuating force is balanced with the restoring force generated by deformation of the elastic piece and the load force born by the motion shaft, a new steady state is achieved.
2. The high-frequency linear electromagnet according to claim 1, wherein the magnetizer comprises a left magnetizer and a right magnetizer, the left magnetizer and the right magnetizer are arranged oppositely, extension parts are arranged on opposite sides of the left magnetizer and the right magnetizer, the end parts of the armatures are respectively positioned between the extension parts of the left magnetizer and the extension parts of the right magnetizer, a first air gap and a second air gap are arranged between the extension parts of the left magnetizer and the armatures, and a third air gap and a fourth air gap are arranged between the extension parts of the right magnetizer and the armatures.
3. A control method of a high-frequency linear electromagnet based on the control method provided by the high-frequency linear electromagnet according to any one of claims 1 to 2, characterized by comprising the steps of: a magnetic field state sensing step, namely collecting control coil current, armature displacement and temperature signals in real time, and constructing a multidimensional state vector reflecting the current working state of the electromagnet; a dual-mode driving adjustment step, judging the current running mode of the electromagnet according to the multi-dimensional state vector, and starting a rapid response mode based on current change rate enhancement if the current running mode is in a step response or high-frequency tracking stage; A dynamic error feedforward compensation step, in a quick response mode, extracting rising edge time sequence characteristics according to historical step response data, generating a feedforward compensation signal synchronous with an input instruction, and superposing the feedforward compensation signal to a driving voltage; A stability checking step, namely continuously monitoring the fluctuation amplitude of the driving current and the displacement tracking residual error, and automatically triggering a mode switching delay mechanism when the product of the fluctuation amplitude of the driving current and the displacement tracking residual error exceeds a preset stability boundary; And updating the self-adaptive parameters, namely updating parameters in the hysteresis compensation model and time sequence weights of the feedforward signals based on residual distribution of the actual displacement track and the ideal track in the current motion process after each complete motion period is finished.
4. The method for controlling a high-frequency linear electromagnet according to claim 3, further comprising a pre-calibration step, wherein the method comprises the step of executing no-load displacement test under the same step excitation twice after the electromagnet is started, and determining a displacement error factor by comparing the deviation of actual displacement curves of the control coils under the same temperature and no-load state twice, wherein the displacement error factor comprises a motion component mass deviation factor and a temperature interference factor, and an adjustment strategy is selected according to the displacement error factor, and comprises a mass self-correction strategy and a thermoelectric compensation cooperative strategy.
5. The method for controlling a high-frequency linear electromagnet according to claim 4, wherein said dual-mode driving adjustment step includes: A quick response activation sub-step of activating a current differential positive feedback path and improving the dynamic gain of the power amplifier when detecting that the change rate of an input instruction exceeds a preset threshold value and the displacement does not enter a steady-state interval yet; a high-linearity locking sub-step of closing a current differential positive feedback path when the displacement change rate is lower than a set value and the current fluctuation range is stable in a preset narrow-band range, and correcting a driving signal through nonlinear predistortion compensation according to a preset displacement current mapping table; and a mode smooth transition sub-step, wherein in the switching process of the quick response mode and the high linearity mode, two paths of control signals are gradually overlapped through an exponential weighting fusion algorithm, and the smooth transition of the control signals is realized through dynamically adjusting the weight ratio.
6. The method for controlling a high-frequency linear electromagnet according to claim 5, wherein the dynamic error feedforward compensation step includes: A fast response compensation sub-step, extracting the characteristics of rising edge slope, peak delay and the like according to the historical step response data, constructing a feedforward compensation signal model so as to synchronously generate a compensation signal and an input instruction, and superposing the compensation signal and the input instruction to a driving voltage after proportional amplification; A high linearity compensation sub-step of inputting a deviation value of the real-time displacement and the target displacement into a preset nonlinear hysteresis loop model to calculate an error correction quantity, and converting the correction quantity into a voltage compensation signal to dynamically adjust the driving current; And a compensation parameter adaptation sub-step of adjusting amplitude gain and phase offset of the feedforward compensation signal according to the dynamic characteristics of the current operation mode, improving the instantaneous peak value of the compensation signal in a quick response mode, and optimizing the smoothness of the compensation signal in a high linearity mode.
7. The method for controlling a high-frequency linear electromagnet according to claim 6, wherein the mass self-correction strategy comprises: an actual mass determining step, namely respectively determining corresponding average displacement deviation according to an actual displacement curve in a twice idle state, and deducing the actual mass of the moving assembly according to a preset theoretical displacement deviation upper limit value and a preset theoretical mass of the moving assembly; and a proportional gain correction sub-step, wherein the mass parameter in the electromagnet motion equation is updated to be the actual mass, and the proportional gain of the current differential positive feedback is corrected according to the ratio of the actual mass to the theoretical mass.
8. The method for controlling a high-frequency linear electromagnet according to claim 6, wherein the temperature-electric compensation cooperative strategy comprises: A database building sub-step, namely building a first mapping table of temperature, maximum allowable current and maximum allowable voltage according to safe working currents of the control coil at different temperatures in the historical data, building a second mapping table of temperature, hysteresis error and compensation quantity correction coefficient according to hysteresis of the electromagnet at different temperatures in the historical data, and building a temperature and hysteresis error model through quadratic polynomial fitting; And a compensation calculation sub-step of synchronously inquiring a first mapping table and a second mapping table according to the real-time temperature of the acquisition control coil, matching to obtain a corresponding maximum allowable current, a corresponding maximum allowable voltage and a compensation quantity correction coefficient, converting the maximum allowable current and the corresponding maximum allowable voltage into a limiting control signal to a control end, and calculating the compensation quantity correction coefficient and the real-time displacement compensation quantity to obtain a corrected compensation quantity through correction calculation.
9. The method of controlling a high frequency linear electromagnet according to claim 6, wherein the stability check step includes setting a weighted product threshold of current fluctuation energy and displacement residual square, determining that the current state is in a critical oscillation state when the product exceeds the weighted product threshold in a plurality of consecutive sampling periods, automatically extending the hold time of the current driving mode, and prohibiting immediate switching to another mode until the product falls back into a safe interval.
10. The method of claim 6, wherein the adaptive parameter updating step includes calculating a displacement residual value from each sampling point to form a residual sequence according to the actual displacement track data and the preset ideal displacement track data after each complete motion period, performing statistical analysis on the residual sequence, extracting the mean value, variance, peak value and distribution interval characteristic of the residual, judging whether the residual is systematic deviation or random fluctuation, correcting hysteresis compensation model parameters according to the residual characteristic if the residual is systematic deviation, and adjusting the feedforward signal time sequence weight if the residual is random fluctuation.

Description

High-frequency linear electromagnet and control method thereof Technical Field The invention relates to the technical field of electromagnet and electromagnetic control, in particular to a high-frequency linear electromagnet and a control method thereof. Background The electro-mechanical converter is widely applied to various electromechanical systems, taking a linear electromagnet as an example, a moving-iron type force (moment) motor is commonly used for a system with quick response and high precision, such as a pre-stage drive of an electrohydraulic servo valve, and the like, and a moving-coil type electromagnet is commonly used for a device with larger stroke and low frequency response requirement, such as a focusing mechanism of an imaging system, and the like. In recent years, along with the development of electromechanical systems, particularly precision and ultra-precision machining systems, the performance of an electromechanical transducer is required to be higher and higher, and taking a microstructure machining system as an example, a key component of a single-point diamond turning machining system is a fast tool servo device, and a core element of the device is the electromechanical transducer. The piezoelectric ceramic and the giant magnetostrictive material have the performance advantages of high working frequency and large output force, and a plurality of micro-displacement electro-mechanical converters take the piezoelectric ceramic and the giant magnetostrictive material as drivers and are successfully applied to precision electromechanical systems such as microstructure processing and the like, but the piezoelectric ceramic and the giant magnetostrictive material have obvious hysteresis, and the nonlinear behavior causes a large amount of energy to be converted into heat, so that the effective stroke is greatly reduced, and the situation is more serious particularly under the high-frequency working condition. Therefore, it is difficult to develop an electromechanical transducer having a large displacement amount at a high frequency using a piezoelectric ceramic or a giant magnetostrictive material. The moving iron type electric-mechanical converter has the characteristics of high frequency response, good linearity, large stroke and the like, the existing mixed rotary or linear quick cutter servo device adopts a moving iron type electric-mechanical converter formed by a plurality of springs and a plurality of coils, but the structure is complex, a plurality of permanent magnets or a plurality of coils are required to be integrated together, the assembly, the adjustment and the control are difficult, the invention patent with the patent number CN2004100664066 discloses a force motor which has the characteristics of compact structure and high frequency response, but has narrower output linear range and poorer linearity, adopts double permanent magnet steel, has complex structure and difficult installation test, and the invention patent with the patent number CN2012100610060 discloses an electric-mechanical converter which takes an elastic device as a high-rigidity spring, has higher frequency response, but outputs angular displacement instead of linear displacement. The problems indicate that the prior art still has obvious defects in the aspects of realizing the collaborative optimization of high frequency, high linearity and low power consumption. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a high-frequency linear electromagnet and a control method thereof, and aims to overcome the inherent technical contradiction existing between high frequency, large stroke, high linearity and strong robustness of a moving iron type electromagnetic driving device in the prior art, so the invention provides the high-frequency linear electromagnet which is symmetrical in structure, controllable in magnetic circuit and differentially modulated in air gap, and the intelligent control method which is matched and developed to integrate multisource state sensing, dual-mode driving switching, dynamic feedforward compensation and parameter self-learning mechanisms, thereby resolving the conflict between high-frequency response and linear precision in principle. In order to achieve the above purpose, the present invention provides the following technical solutions: The high-frequency linear electromagnet comprises permanent magnet steel, a magnetizer, a magnetic yoke, a moving shaft, an armature, a control coil and an elastic piece, wherein the permanent magnet steel and the magnetic yoke are both positioned on one side of the magnetizer, a magnetic force space is arranged in the magnetizer, the armature is positioned in the magnetic force space, an air gap is arranged between the armature and the magnetizer, the control coil is wound on the armature, the moving shaft vertically passes through the armature and is fixedly connected with the armature, and th