Current intensity oscillation expansion brushless motor zero position dynamic calibration method and device

Abstract

The invention provides a current intensity oscillation expansion brushless motor zero position dynamic calibration method and device, and the method comprises the steps: constructing an angle convergence reference curve and a current intensity oscillation expansion reference curve according to the calibration parameters of a to-be-calibrated motor; the current intensity oscillation expansion reference curve is used for representing a change mode that the d-axis current intensity of the motor rotor is expanded in a bidirectional reciprocating oscillation mode along with time; driving the to-be-calibrated motor to operate according to the angle convergence reference curve and the current intensity oscillation expansion reference curve, and obtaining an angle actual curve and a current intensity actual curve; comparing the angle actual curve with the angle convergence reference curve, comparing the current intensity actual curve with the current intensity oscillation expansion reference curve, and determining a zero calibration effect of the motor to be calibrated; when the zero calibration effect meets the preset requirement, it is determined that zero calibration of the to-be-calibrated motor is completed. Thus, efficient and reliable dynamic calibration of the zero position of the motor can be achieved, accidents caused by wrong calibration are avoided, and safe and reliable starting and running of the motor are guaranteed.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a method and device for dynamically calibrating the zero position of a brushless motor with current intensity oscillation expansion. Background Art

[0002] For incremental encoder feedback brushless motors, after the system is completely powered off, the motor zero position calibration must be performed when it is restarted to ensure that the motor control system can accurately control the position and movement of the motor. Existing zero position calibration methods often only set a fixed angle zero position, and pass a sufficiently large current to allow the rotor permanent magnet to overcome the static friction torque, dynamic friction torque, and resistance torque, and try to align to this angle zero position.

[0003] However, in engineering practice, the motor may be in a weak equilibrium state during the calibration process. The zero-position pull generated by the calibration current is nearly parallel to the permanent magnet, and the zeroing torque generated is very small, even insufficient to overcome the static friction torque and resistance torque generated by the motor, reducer, load, etc., resulting in calibration failure. The motor shaft is also often subjected to various unexpected interference torques, which makes it impossible for the motor rotor permanent magnet to align to the angle zero position. The accuracy of the zero-position calibration is low, affecting the stability of the motor operation. In addition, the existing calibration method lacks monitoring of the zero-position calibration effect, which causes the motor control system to control the motor to be put into production when the calibration error is large, which is easy to cause accidents. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a method and device for dynamic calibration of the zero position of a brushless motor with current intensity oscillation amplification, so as to solve the problems of low accuracy and reliability of the zero position calibration method in the prior art, realize efficient and reliable dynamic calibration of the motor zero position, avoid accidents caused by incorrect calibration, and ensure the safe and reliable starting and operation of the motor.

[0005] The present application provides a method for dynamic calibration of zero position of a brushless motor with current intensity oscillation expansion, the method comprising:

[0006] Determine the calibration parameters of the motor to be calibrated;

[0007] According to the calibration parameters, an angle convergence reference curve and a current intensity oscillation expansion reference curve of the motor to be calibrated are constructed; wherein the angle convergence reference curve is used to characterize the motion mode of the motor rotor converging from the initial angle position to the angle zero position over time; the current intensity oscillation expansion reference curve is used to characterize the change mode of the d-axis current intensity of the motor rotor expanding in a bidirectional reciprocating oscillation manner over time;

[0008] The motor to be calibrated is driven to run according to the angle convergence reference curve and the current intensity oscillation expansion reference curve, and an actual angle curve and an actual current intensity curve of the motor to be calibrated are obtained; wherein the actual angle curve refers to a curve formed by the actual angle position of the motor rotor at different operating times; the actual current intensity curve refers to a curve formed by the d-axis current intensity of the motor rotor at different operating times;

[0009] Comparing the angle actual curve with the angle convergence reference curve, and comparing the current intensity actual curve with the current intensity oscillation expansion reference curve, to determine the zero position calibration effect of the motor to be calibrated;

[0010] When the zero-position calibration effect meets the preset requirement, it is determined that the motor to be calibrated has completed the zero-position calibration.

[0011] Furthermore, obtaining the actual angle curve and the actual current intensity curve of the motor to be calibrated includes:

[0012] Determine the stop angle according to the angle zero position and the preset error angle value;

[0013] Recording the actual angular position and the actual d-axis current intensity corresponding to each running moment until the actual angular position corresponding to any running moment reaches the stop angle;

[0014] Based on the actual angle position corresponding to each recorded operation moment, the angle actual curve is obtained; and based on the actual d-axis current intensity corresponding to each recorded operation moment, the current intensity actual curve is obtained.

[0015] Further, comparing the angle actual curve with the angle convergence reference curve, and comparing the current intensity actual curve with the current intensity oscillation expansion reference curve, to determine the zero position calibration effect of the motor to be calibrated, includes:

[0016] Comparing the angle actual curve with the angle convergence reference curve, intercepting a preset time length from the running moment when the stop angle is reached forward, to obtain an angle difference curve;

[0017] By performing an integral operation on the angle difference curve, an average angle error of the motor to be calibrated within the preset time length is obtained; wherein the average angle error is used to measure the zero-position calibration effect of the motor to be calibrated;

[0018] Comparing the actual current intensity curve with the current intensity oscillation expansion reference curve, intercepting a preset time from the running moment of reaching the stop angle forward to obtain a current intensity difference curve;

[0019] By integrating the current intensity difference curve, the average current intensity error of the motor to be calibrated within the preset time period is obtained; wherein the average current intensity error is used to measure the zero-position calibration effect of the motor to be calibrated.

[0020] Furthermore, the dynamic calibration method further includes determining that the zero position calibration effect meets the preset requirements in the following manner:

[0021] When the average angle error is less than a preset angle error threshold, and the average current intensity error is less than a preset current intensity error threshold, it is determined that the zero position calibration effect meets the preset requirements.

[0022] Further, the calibration parameters include the current bidirectional oscillation frequency and the current amplification coefficient; determining the calibration parameters of the motor to be calibrated includes:

[0023] Obtaining the rated speed, rated current and overload capacity of the motor to be calibrated;

[0024] Determining a motor frequency corresponding to the motor to be calibrated according to the rated speed of the motor to be calibrated;

[0025] Reducing the motor frequency by a predetermined multiple to determine the current bidirectional oscillation frequency;

[0026] The current amplification factor is determined according to the rated current and overload capacity of the motor to be calibrated; wherein the current amplification factor is used to control the amplification speed of the d-axis current intensity of the motor rotor.

[0027] Further, according to the calibration parameters, a current intensity oscillation expansion reference curve of the motor to be calibrated is constructed, including:

[0028] Determining a current bidirectional oscillation function according to the current bidirectional oscillation frequency;

[0029] The current intensity oscillation amplification reference curve is constructed according to the product of the current amplification coefficient and the current bidirectional oscillation function.

[0030] Furthermore, the formula of the current intensity oscillation expansion reference curve is expressed as:

[0031] R ref =k×t×sin(2πft)

[0032] Among them, R ref represents the current intensity oscillation convergence reference curve; k represents the current amplification coefficient; f represents the current bidirectional oscillation frequency.

[0033] Furthermore, the dynamic calibration method also includes:

[0034] When the zero-position calibration effect does not meet the preset requirement, determining whether the number of zero-position calibrations of the motor to be calibrated reaches a preset number threshold;

[0035] If it is not reached, re-calibrate the motor to be calibrated at zero position;

[0036] If it has been reached, an alarm signal is generated and sent to relevant personnel.

[0037] The embodiment of the present application also provides a current intensity oscillation expansion brushless motor zero position dynamic calibration device, the dynamic calibration device comprising:

[0038] A determination module, used to determine the calibration parameters of the motor to be calibrated;

[0039] A construction module is used to construct an angle convergence reference curve and a current intensity oscillation expansion reference curve of the motor to be calibrated according to the calibration parameters; wherein the angle convergence reference curve is used to characterize the motion mode of the motor rotor converging from an initial angle position to an angle zero position over time; and the current intensity oscillation expansion reference curve is used to characterize the change mode of the d-axis current intensity of the motor rotor expanding over time in a bidirectional reciprocating oscillation manner;

[0040] An acquisition module is used to drive the motor to be calibrated to run according to the angle convergence reference curve and the current intensity oscillation expansion reference curve, and acquire an angle actual curve and a current intensity actual curve of the motor to be calibrated; wherein the angle actual curve refers to a curve formed by the actual angle position of the motor rotor at different operating times; the current intensity actual curve refers to a curve formed by the d-axis current intensity of the motor rotor at different operating times;

[0041] A comparison module, used for comparing the actual angle curve with the angle convergence reference curve, and comparing the actual current intensity curve with the current intensity oscillation expansion reference curve, to determine the zero position calibration effect of the motor to be calibrated;

[0042] The judging module is used to determine that the zero-position calibration of the motor to be calibrated has been completed when the zero-position calibration effect meets the preset requirements.

[0043] An embodiment of the present application also provides an electronic device, including: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are executed by the processor, the steps of the current intensity oscillation-enlarged brushless motor zero position dynamic calibration method are performed as described above.

[0044] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for dynamically calibrating the zero position of a brushless motor with amplified current intensity oscillation are executed as described above.

[0045] The embodiment of the present application provides a method and device for dynamic calibration of the zero position of a brushless motor with current intensity oscillation expansion. On the one hand, the angle convergence reference curve and the current intensity oscillation expansion reference curve are used in combination for dynamic calibration, so that the angle position dynamically approaches the angle zero position; at the same time, the d-axis current intensity is continuously expanded in a bidirectional reciprocating oscillation manner to increase the torque, thereby breaking the static and quasi-static balance produced by the large initial static friction torque and the nonlinear dynamic friction torque, so that the motor can produce significant calibration actions, overcome various interference torques, and improve the calibration accuracy; on the other hand, by comparing the actual angle curve and the angle oscillation convergence reference curve, the zero position calibration effect of the motor can be quantitatively determined to improve the reliability of the calibration; and when it is determined that the zero position calibration effect meets the preset requirements, the zero position calibration is completed, which helps to ensure the safe operation of the motor.

[0046] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 A flow chart of a method for dynamically calibrating the zero position of a brushless motor with amplified current intensity oscillation provided in an embodiment of the present application is shown;

[0049] Figure 2 A schematic diagram of a calibration process provided in an embodiment of the present application is shown;

[0050] Figure 3 A schematic diagram of the structure of a current intensity oscillation-amplified brushless motor zero position dynamic calibration device provided in an embodiment of the present application is shown;

[0051] Figure 4 A schematic structural diagram of an electronic device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0052] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0053] Research has found that the existing zero-position calibration method is very simple. It often only sets a fixed angle zero position, and then aligns the d-axis of the motor FOC algorithm dq coordinate system to the specified angle zero position q0. By passing a sufficiently large current, the NS poles of the rotor permanent magnet can overcome the static friction torque, dynamic friction torque, and resistance torque and try to align to this angle zero position.

[0054] However, in engineering practice, the motor may be in a weak equilibrium state during the calibration process. The zero-position pull generated by the calibration current is nearly parallel to the permanent magnet, and the zeroing torque generated is very small, even insufficient to overcome the static friction torque and resistance torque generated by the motor, reducer, load, etc., resulting in calibration failure. The motor shaft is also often subjected to various unexpected interference torques, which makes it impossible for the motor rotor permanent magnet to align to the angle zero position. The accuracy of the zero-position calibration is low, affecting the stability of the motor operation. In addition, the existing calibration method lacks monitoring of the zero-position calibration effect, which causes the motor control system to control the motor to be put into production when the calibration error is large, which is easy to cause accidents.

[0055] Based on this, an embodiment of the present application provides a method for dynamic calibration of the zero position of a brushless motor with current intensity oscillation expansion to solve the problems of low accuracy and reliability of the zero position calibration method in the prior art.

[0056] See also Figure 1 , Figure 1 The present invention provides a flow chart of a method for dynamically calibrating the zero position of a brushless motor with current intensity oscillation expansion. The dynamic calibration method can be automatically executed by a motor driver. Figure 1 As shown in , the dynamic calibration method provided in the embodiment of the present application includes:

[0057] S101, determining calibration parameters of the motor to be calibrated.

[0058] Among them, the calibration parameters may include current calibration parameters and angle calibration parameters; among them, the current calibration parameters include current bidirectional oscillation frequency and current amplification coefficient; the current amplification coefficient is used to control the amplification speed of the d-axis current intensity of the motor rotor.

[0059] The angle calibration parameters may include a deviation angle value and an angle attenuation coefficient. The deviation angle value refers to the angle value of the initial angle position of the motor rotor (more specifically, the permanent magnet on the rotor) deviating from the angle zero position; the angle attenuation coefficient is used to control the angle convergence speed of the motor rotor, that is, the speed at which the permanent magnet approaches the angle zero position.

[0060] In specific implementation, the parameter values ​​of various calibration parameters can be set according to the actual application scenario of the motor and the calibration requirements to achieve flexible calibration of the motor.

[0061] In a possible implementation, step S101 may include:

[0062] S1011. Obtain the rated speed, rated current, and overload capacity of the motor to be calibrated.

[0063] The overload capacity of a motor refers to the ability of the motor to maintain stable operation for a short period of time when the load exceeds its rated load, and is usually expressed in multiples. For example, the overload capacity of a general motor can reach 3 times its rated load, and the duration can usually be 1 minute.

[0064] S1012: Determine a motor frequency corresponding to the motor to be calibrated according to the rated speed of the motor to be calibrated.

[0065] S1013, reducing the motor frequency by a predetermined multiple to determine the current bidirectional oscillation frequency.

[0066] For steps S1012 and S1013, the bidirectional oscillation frequency f when the motor current is expanded is related to the rated speed of the motor; specifically, the rated speed of the motor to be calibrated has a corresponding frequency, for example, the rated speed of the motor is 3000RPM, that is, 50Hz, and f can reduce the motor frequency by a predetermined multiple and take it as no more than one tenth of the frequency generated by the rated speed of the motor, that is, f is no more than 5Hz; for example, it can be taken as 2Hz.

[0067] S1014. Determine the current amplification factor according to the rated current and overload capacity of the motor to be calibrated.

[0068] Here, the parameter value of the current expansion factor k is related to the rated current and overload capacity of the motor. For example, the rated current of the motor is 5A, and it can generally be overloaded 3 times, that is, 15A; the zero calibration process takes a total of 5 seconds, during which the current intensity oscillates and expands the reference curve Rref The current intensity reference value can reach 3 times of the rated current of the motor, then k = 15A / 5s = 3A / s.

[0069] S102: constructing an angle convergence reference curve and a current intensity oscillation expansion reference curve of the motor to be calibrated according to the calibration parameters.

[0070] Among them, the angle convergence reference curve is used to characterize the movement mode of the motor rotor converging from the initial angle position to the angle zero position over time; the current intensity oscillation expansion reference curve is used to characterize the change mode of the d-axis current intensity of the motor rotor expanding in a bidirectional reciprocating oscillation manner over time.

[0071] In a possible implementation, step S102 may include:

[0072] The current bidirectional oscillation function is determined according to the current bidirectional oscillation frequency; and the current intensity oscillation amplification reference curve is constructed according to the product of the current amplification coefficient and the current bidirectional oscillation function.

[0073] In one example, the formula of the current intensity oscillation expansion reference curve can be expressed as:

[0074] R ref =k×t×sin(2πft)

[0075] Among them, R ref It represents the current intensity oscillation convergence reference curve, each point on the curve represents the rotor d-axis current intensity in the motor stator coordinate system at the running time; k represents the current amplification coefficient; f represents the current bidirectional oscillation frequency.

[0076] See below Figure 2 , Figure 2 This is a schematic diagram of a calibration process when the angle position converges in one direction provided by an embodiment of the present application. Figure 2 Middle angle convergence reference curve Q ref As shown, the angle position converges to the angle zero position; if the current intensity oscillates, the reference curve R ref As shown, the current intensity increases and decreases in a bidirectional reciprocating oscillation manner, but the oscillation amplitude gradually increases.

[0077] It should be noted that the alignment torque of the brushless motor is proportional to the d-axis current intensity, that is, the alignment torque can be adjusted by adjusting the d-axis current.

[0078] It can be seen that as time goes by, the oscillation of current intensity expands, causing the alignment torque intensity to oscillate and expand accordingly. The oscillation can better break the static and quasi-static balance caused by the large initial static friction torque and nonlinear dynamic friction torque, overcome various resistances, and perform significant calibration actions; on the other hand, the expansion of current intensity oscillation makes the effective value of current in the zero-position dynamic calibration process significantly smaller than the effective value of current during linear growth; by reducing the effective value of current, energy consumption can be reduced and energy can be saved. More importantly, research has found that motors, especially motor drivers, are very sensitive to current size. By reducing the effective value of current in the dynamic calibration process, the motor load can be reduced, the calibration safety can be better guaranteed, and the safety hazards caused by excessive current can be reduced.

[0079] In addition, for the motion mode represented by the angle convergence reference curve, the angular position of the motor rotor can converge in one direction or in two-way reciprocating oscillation; Figure 2 A schematic diagram of unidirectional convergence of the angle position is shown. Further, the angle position can also converge in a reciprocal form or an exponential form.

[0080] Exemplarily, when the angular position of the motor to be calibrated converges unidirectionally in an exponential form, the formula of the angle convergence reference curve can be expressed as:

[0081] Q ref =q0+a×e -bt

[0082] Among them, Q ref represents the angle convergence reference curve; q0 represents the angle zero position, in degrees; Q ref and q0 are both the rotor d-axis angles in the motor stator coordinate system; a represents the deviation angle value; b represents the angle attenuation coefficient; t represents the running time, in seconds.

[0083] S103 . Drive the motor to be calibrated to operate according to the angle convergence reference curve and the current intensity oscillation expansion reference curve, and obtain an actual angle curve and an actual current intensity curve of the motor to be calibrated.

[0084] Among them, the actual angle curve refers to a curve formed by the actual angle position of the motor rotor corresponding to different operating moments; the actual current intensity curve refers to a curve formed by the d-axis current intensity of the motor rotor corresponding to different operating moments.

[0085] In specific implementation, the FOC algorithm of the motor driver can be combined for control. FOC (Field-Oriented Control) is a control algorithm for AC motors (such as brushless DC motors BLDC and permanent magnet synchronous motors PMSM, etc.). Its core idea is to decompose the three-phase current and voltage of the motor into two independent DC components: the magnetic field component (d-axis) and the torque component (q-axis), thereby achieving independent control of the motor magnetic field and torque.

[0086] In an example, the actual angle curve and the actual current intensity curve of the motor to be calibrated may be obtained by the following steps:

[0087] The stop angle is determined according to the angle zero position and the preset error angle value; the actual angle position and the actual d-axis current intensity corresponding to each operating moment are recorded until the actual angle position corresponding to any operating moment reaches the stop angle; based on the recorded actual angle position corresponding to each operating moment, the angle actual curve is obtained; and based on the recorded actual d-axis current intensity corresponding to each operating moment, the current intensity actual curve is obtained.

[0088] Continue reading Figure 2 , driven by the d-axis current mode, the motor starts running and converges to the reference curve Q according to the angle ref Gradually approaching zero position q0, while expanding the reference curve R according to the current intensity oscillation ref The torque strength is gradually increased in a bidirectional reciprocating oscillation manner; when Q ref When the deviation d=abs(q1-q0) reaches the preset allowable error angle value, the motor stops and the motor driver automatically records the actual angle curve Q. act and the actual current intensity curve R act The deviation d can be set according to the required calibration accuracy, such as ±0.1°.

[0089] S104, comparing the actual angle curve with the angle convergence reference curve, and comparing the actual current intensity curve with the current intensity oscillation expansion reference curve, to determine the zero-position calibration effect of the motor to be calibrated.

[0090] In this step, by comparing the actual angle curve and the angle convergence reference curve, the degree of deviation in angle between the actual curve and the reference curve during the dynamic zero calibration process can be determined; at the same time, by comparing the actual current intensity curve and the current intensity oscillation expansion reference curve, the degree of deviation in current intensity between the actual curve and the reference curve during the dynamic zero calibration process can be determined; and then the degree of deviation in angle and the degree of deviation in current intensity are combined to determine a more comprehensive zero calibration effect.

[0091] In a possible implementation, step S104 may include:

[0092] S1041. Compare the actual angle curve with the angle convergence reference curve, and obtain an angle difference curve by intercepting a preset time from the running moment when the stop angle is reached.

[0093] S1042. Obtain an average angle error of the motor to be calibrated within the preset time period by performing an integral operation on the angle difference curve; wherein the average angle error is used to measure the zero-position calibration effect of the motor to be calibrated.

[0094] S1043: Compare the current intensity actual curve with the current intensity oscillation expansion reference curve, and obtain a current intensity difference curve by intercepting a preset time from the running moment when the stop angle is reached.

[0095] S1044. Obtain an average current intensity error of the motor to be calibrated within the preset time period by integrating the current intensity difference curve; wherein the average current intensity error is used to measure the zero-position calibration effect of the motor to be calibrated.

[0096] Here, the preset time length is the integration time span T0; more specifically, the embodiment of the present application defines an evaluation function J1 of the angle zero calibration effect and an evaluation function J2 of the current intensity zero calibration effect by comparing the angle actual curve and the angle oscillation convergence reference curve, and the formula can be expressed as:

[0097]

[0098] The size of the average angle error (i.e., the value of the evaluation function J1) reflects the severity of the deviation of the actual motion curve of the angle from the angle reference curve during the process of the permanent magnet approaching the zero position q0; the size of the average current intensity error (i.e., the value of the evaluation function J2) reflects the severity of the deviation of the actual change curve of the current intensity from the current intensity reference curve during the process of the permanent magnet approaching the zero position q0. Obviously, the values ​​of J1 and J2 are very small, indicating that the actual approximation curve of the permanent magnet basically coincides with the angle reference curve, that is, the approximation convergence effect is very good, at this time the motor calibration is successful, and the calibration dynamic process and calibration results are very good. When the value of J1 or J2 is not small enough, that is, it is greater than the preset error threshold, the calibration error is too large, the motor calibration fails, and it is necessary to recalibrate or check the problem of the motor system.

[0099] Thus, compared with the method of only calculating the difference between the last actual calibration zero position and the preset angle zero position, or only calculating the difference between the last actual current intensity and the preset current intensity, the evaluation function J designed in the embodiment of the present application is AJ and J2 can better reflect the overall severity of the deviation of the actual motion curve from the angle reference curve during the overall process of zero-position dynamic calibration, thereby more accurately and comprehensively measuring the zero-position calibration effect.

[0100] S105. When the zero-position calibration effect meets the preset requirement, determine that the motor to be calibrated has completed the zero-position calibration.

[0101] Here, when the average angle error is less than a preset error threshold, and the average current intensity error is less than a preset current intensity error threshold, it is determined that the zero position calibration effect meets the preset requirements, and the motor is allowed to perform subsequent work.

[0102] When the zero-position calibration effect does not meet the preset requirements (i.e. J1 or J2 is greater than or equal to the preset error threshold), it means that the zero-position calibration has failed. After that, it is determined whether the number of zero-position calibrations of the motor to be calibrated reaches the preset number threshold. If not, the motor to be calibrated is automatically recalibrated. If it has reached, an alarm signal is generated and sent to relevant personnel to remind them to intervene manually. The number threshold can be set according to actual needs, such as 3 times.

[0103] The embodiment of the present application provides a method for dynamic calibration of the zero position of a brushless motor by current intensity oscillation expansion. On the one hand, the angle convergence reference curve and the current intensity oscillation expansion reference curve are used in combination for dynamic calibration, so that the angle position dynamically approaches the angle zero position; at the same time, the d-axis current intensity is continuously expanded in a bidirectional reciprocating oscillation manner to increase the torque, thereby breaking the static and quasi-static balance produced by the large initial static friction torque and the nonlinear dynamic friction torque, so that the motor can produce significant calibration actions, overcome various interference torques, and improve the calibration accuracy; on the other hand, by comparing the actual angle curve and the angle oscillation convergence reference curve, the zero position calibration effect of the motor can be quantitatively determined to improve the reliability of the calibration; and when it is determined that the zero position calibration effect meets the preset requirements, the zero position calibration is completed, which helps to ensure the safe operation of the motor.

[0104] See also Figure 3 , Figure 3 This is a schematic diagram of the structure of a current intensity oscillation expansion brushless motor zero position dynamic calibration device provided in an embodiment of the present application. Figure 3 As shown in , the dynamic calibration device 300 includes:

[0105] A determination module 310 is used to determine calibration parameters of the motor to be calibrated;

[0106] A construction module 320 is used to construct an angle convergence reference curve and a current intensity oscillation expansion reference curve of the motor to be calibrated according to the calibration parameters; wherein the angle convergence reference curve is used to characterize the motion mode of the motor rotor converging from the initial angle position to the angle zero position over time; the current intensity oscillation expansion reference curve is used to characterize the change mode of the d-axis current intensity of the motor rotor expanding in a bidirectional reciprocating oscillation manner over time;

[0107] The acquisition module 330 is used to drive the motor to be calibrated to run according to the angle convergence reference curve and the current intensity oscillation expansion reference curve, and acquire the angle actual curve and current intensity actual curve of the motor to be calibrated; wherein the angle actual curve refers to the curve formed by the actual angle position of the motor rotor at different operating times; the current intensity actual curve refers to the curve formed by the d-axis current intensity of the motor rotor at different operating times;

[0108] A comparison module 340 is used to compare the actual angle curve with the angle convergence reference curve, and to compare the actual current intensity curve with the current intensity oscillation expansion reference curve, so as to determine the zero position calibration effect of the motor to be calibrated;

[0109] The judgment module 350 is used to determine that the zero-position calibration of the motor to be calibrated has been completed when the zero-position calibration effect meets the preset requirements.

[0110] Furthermore, when the acquisition module 330 is used to acquire the actual angle curve and the actual current intensity curve of the motor to be calibrated, the acquisition module 330 is used to:

[0111] Determine the stop angle according to the angle zero position and the preset error angle value;

[0112] Recording the actual angular position and the actual d-axis current intensity corresponding to each running moment until the actual angular position corresponding to any running moment reaches the stop angle;

[0113] Based on the actual angle position corresponding to each recorded operation moment, the angle actual curve is obtained; and based on the actual d-axis current intensity corresponding to each recorded operation moment, the current intensity actual curve is obtained.

[0114] Further, when the comparison module 340 is used to compare the angle actual curve with the angle convergence reference curve, and to compare the current intensity actual curve with the current intensity oscillation expansion reference curve to determine the zero position calibration effect of the motor to be calibrated, the comparison module 340 is used to:

[0115] Comparing the angle actual curve with the angle convergence reference curve, intercepting a preset time length from the running moment when the stop angle is reached forward, to obtain an angle difference curve;

[0116] By performing an integral operation on the angle difference curve, an average angle error of the motor to be calibrated within the preset time length is obtained; wherein the average angle error is used to measure the zero-position calibration effect of the motor to be calibrated;

[0117] Comparing the actual current intensity curve with the current intensity oscillation expansion reference curve, intercepting a preset time from the running moment of reaching the stop angle forward to obtain a current intensity difference curve;

[0118] By integrating the current intensity difference curve, the average current intensity error of the motor to be calibrated within the preset time period is obtained; wherein the average current intensity error is used to measure the zero-position calibration effect of the motor to be calibrated.

[0119] Furthermore, the judging module 350 is further configured to determine whether the zero position calibration effect meets the preset requirement by:

[0120] When the average angle error is less than a preset angle error threshold, and the average current intensity error is less than a preset current intensity error threshold, it is determined that the zero position calibration effect meets the preset requirements.

[0121] Furthermore, the calibration parameters include the current bidirectional oscillation frequency and the current amplification coefficient; when the determination module 310 is used to determine the calibration parameters of the motor to be calibrated, the determination module is used to:

[0122] Obtaining the rated speed, rated current and overload capacity of the motor to be calibrated;

[0123] Determining a motor frequency corresponding to the motor to be calibrated according to the rated speed of the motor to be calibrated;

[0124] Reducing the motor frequency by a predetermined multiple to determine the current bidirectional oscillation frequency;

[0125] The current amplification factor is determined according to the rated current and overload capacity of the motor to be calibrated; wherein the current amplification factor is used to control the amplification speed of the d-axis current intensity of the motor rotor.

[0126] Furthermore, when the construction module 320 is used to construct the angle convergence reference curve and the current intensity oscillation expansion reference curve of the motor to be calibrated according to the calibration parameters, the construction module 320 is used to:

[0127] Determining a current bidirectional oscillation function according to the current bidirectional oscillation frequency;

[0128] The current intensity oscillation amplification reference curve is constructed according to the product of the current amplification coefficient and the current bidirectional oscillation function.

[0129] Furthermore, the formula of the current intensity oscillation expansion reference curve is expressed as:

[0130] R ref =k×t×sin(2πft)

[0131] Among them, R ref represents the current intensity oscillation convergence reference curve; k represents the current amplification coefficient; f represents the current bidirectional oscillation frequency.

[0132] Furthermore, the determination module 350 is further configured to:

[0133] When the zero-position calibration effect does not meet the preset requirement, determining whether the number of zero-position calibrations of the motor to be calibrated reaches a preset number threshold;

[0134] If it is not reached, re-calibrate the motor to be calibrated at zero position;

[0135] If it has been reached, an alarm signal is generated and sent to relevant personnel.

[0136] See also Figure 4 , Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 4 As shown in , the electronic device 400 includes a processor 410 , a memory 420 and a bus 430 .

[0137] The memory 420 stores machine-readable instructions executable by the processor 410. When the electronic device 400 is running, the processor 410 communicates with the memory 420 via the bus 430. When the machine-readable instructions are executed by the processor 410, the above-mentioned Figure 1 The steps of the method for dynamically calibrating the zero position of a brushless motor by expanding the current intensity oscillation in the method embodiment shown are specifically implemented in the method embodiment and will not be described in detail here.

[0138] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the computer program can execute the above-mentioned Figure 1 The steps of the method for dynamically calibrating the zero position of a brushless motor by expanding the current intensity oscillation in the method embodiment shown are specifically implemented in the method embodiment and will not be described in detail here.

[0139] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0140] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0141] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0142] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0143] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application can essentially or in other words, the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0144] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for dynamic calibration of zero position of brushless motor with current intensity oscillation expansion, characterized in that: The dynamic calibration method comprises: Determine the calibration parameters of the motor to be calibrated; According to the calibration parameters, an angle convergence reference curve and a current intensity oscillation expansion reference curve of the motor to be calibrated are constructed; wherein the angle convergence reference curve is used to characterize the motion mode of the motor rotor converging from the initial angle position to the angle zero position over time; the current intensity oscillation expansion reference curve is used to characterize the change mode of the d-axis current intensity of the motor rotor expanding in a bidirectional reciprocating oscillation manner over time; The motor to be calibrated is driven to run according to the angle convergence reference curve and the current intensity oscillation expansion reference curve, and an actual angle curve and an actual current intensity curve of the motor to be calibrated are obtained; wherein the actual angle curve refers to a curve formed by the actual angle position of the motor rotor at different operating times; the actual current intensity curve refers to a curve formed by the d-axis current intensity of the motor rotor at different operating times; Comparing the angle actual curve with the angle convergence reference curve, and comparing the current intensity actual curve with the current intensity oscillation expansion reference curve, to determine the zero position calibration effect of the motor to be calibrated; When the zero-position calibration effect meets the preset requirement, it is determined that the motor to be calibrated has completed the zero-position calibration.

2. The dynamic calibration method according to claim 1, characterized in that: Obtaining the actual angle curve and the actual current intensity curve of the motor to be calibrated, including: Determine the stop angle according to the angle zero position and the preset error angle value; Recording the actual angular position and the actual d-axis current intensity corresponding to each running moment until the actual angular position corresponding to any running moment reaches the stop angle; Based on the actual angle position corresponding to each recorded operation moment, the angle actual curve is obtained; and based on the actual d-axis current intensity corresponding to each recorded operation moment, the current intensity actual curve is obtained.

3. The dynamic calibration method according to claim 2, characterized in that: Comparing the angle actual curve with the angle convergence reference curve, and comparing the current intensity actual curve with the current intensity oscillation expansion reference curve, to determine the zero position calibration effect of the motor to be calibrated, includes: Comparing the angle actual curve with the angle convergence reference curve, intercepting a preset time length from the running moment when the stop angle is reached forward, to obtain an angle difference curve; By performing an integral operation on the angle difference curve, an average angle error of the motor to be calibrated within the preset time length is obtained; wherein the average angle error is used to measure the zero-position calibration effect of the motor to be calibrated; Comparing the actual current intensity curve with the current intensity oscillation expansion reference curve, intercepting a preset time from the running moment of reaching the stop angle forward to obtain a current intensity difference curve; By integrating the current intensity difference curve, the average current intensity error of the motor to be calibrated within the preset time period is obtained; wherein the average current intensity error is used to measure the zero-position calibration effect of the motor to be calibrated.

4. The dynamic calibration method according to claim 3, characterized in that: The dynamic calibration method further includes determining that the zero position calibration effect meets the preset requirements by: When the average angle error is less than a preset angle error threshold, and the average current intensity error is less than a preset current intensity error threshold, it is determined that the zero position calibration effect meets the preset requirements.

5. The dynamic calibration method according to claim 1, characterized in that: The calibration parameters include the current bidirectional oscillation frequency and the current amplification coefficient; Determine the calibration parameters of the motor to be calibrated, including: Obtaining the rated speed, rated current and overload capacity of the motor to be calibrated; Determining a motor frequency corresponding to the motor to be calibrated according to the rated speed of the motor to be calibrated; Reducing the motor frequency by a predetermined multiple to determine the current bidirectional oscillation frequency; The current amplification factor is determined according to the rated current and overload capacity of the motor to be calibrated; wherein the current amplification factor is used to control the amplification speed of the d-axis current intensity of the motor rotor.

6. The dynamic calibration method according to claim 5, characterized in that: According to the calibration parameters, constructing a current intensity oscillation expansion reference curve of the motor to be calibrated, including: Determining a current bidirectional oscillation function according to the current bidirectional oscillation frequency; The current intensity oscillation amplification reference curve is constructed according to the product of the current amplification coefficient and the current bidirectional oscillation function.

7. The dynamic calibration method according to claim 5, characterized in that: The formula of the current intensity oscillation expansion reference curve is expressed as: r ref =k×t×sin(2πft) Among them, R ref represents the current intensity oscillation convergence reference curve; k represents the current amplification coefficient; f represents the current bidirectional oscillation frequency.

8. The dynamic calibration method according to claim 1, characterized in that: The dynamic calibration method also includes: When the zero-position calibration effect does not meet the preset requirement, determining whether the number of zero-position calibrations of the motor to be calibrated reaches a preset number threshold; If it is not reached, re-calibrate the motor to be calibrated at zero position; If it has been reached, an alarm signal is generated and sent to relevant personnel.

9. A current intensity oscillation expansion brushless motor zero position dynamic calibration device, characterized in that: The dynamic calibration device comprises: A determination module, used to determine the calibration parameters of the motor to be calibrated; A construction module is used to construct an angle convergence reference curve and a current intensity oscillation expansion reference curve of the motor to be calibrated according to the calibration parameters; wherein the angle convergence reference curve is used to characterize the motion mode of the motor rotor converging from an initial angle position to an angle zero position over time; and the current intensity oscillation expansion reference curve is used to characterize the change mode of the d-axis current intensity of the motor rotor expanding over time in a bidirectional reciprocating oscillation manner; An acquisition module is used to drive the motor to be calibrated to run according to the angle convergence reference curve and the current intensity oscillation expansion reference curve, and acquire an angle actual curve and a current intensity actual curve of the motor to be calibrated; wherein the angle actual curve refers to a curve formed by the actual angle position of the motor rotor at different operating times; the current intensity actual curve refers to a curve formed by the d-axis current intensity of the motor rotor at different operating times; A comparison module, used for comparing the actual angle curve with the angle convergence reference curve, and comparing the actual current intensity curve with the current intensity oscillation expansion reference curve, to determine the zero position calibration effect of the motor to be calibrated; The judging module is used to determine that the zero-position calibration of the motor to be calibrated has been completed when the zero-position calibration effect meets the preset requirements.

10. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and the machine-readable instructions are executed by the processor to execute the steps of the current intensity oscillation expansion brushless motor zero position dynamic calibration method as described in any one of claims 1 to 8.

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