Motor parameter identification method based on finite width rectangular pulse excitation

Abstract

The invention relates to the technical field of motor control, and discloses a motor parameter identification method based on finite width rectangular pulse excitation. Comprising the following steps: S01, generating a pulse signal; s02, judging whether to enter a recursive calculation mode or not; s03, based on a static setting principle or a dynamic adjustment principle, calculating a steady-state amplification factor and a time constant of the to-be-tested motor at a sampling moment; s04, whether excitation response output operation is executed or not is judged; s05, outputting a steady-state amplification factor and a time constant of the to-be-tested motor at a standard moment; according to the invention, it can be ensured that the pulse signal interacts with the to-be-tested motor in an extremely short time, so that the interference influence caused by the long-time excitation action of the pulse signal and the to-be-tested motor is avoided; two parallel calculation identification logics are provided for accurate calculation of the steady-state amplification factor and the time constant, and the compatibility between the motor parameter calculation identification logics and single-chip microcomputers with different performances is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, more particularly, the present application relates to a motor parameter identification method based on limited-width rectangular pulse excitation. BACKGROUND

[0002] In a motor control system, in order to achieve the effect of high-precision motor speed regulation or position control, it is usually necessary to first establish a mathematical model matched with the characteristics and parameters of the motor, and then perform speed regulation or position control operation on the motor through the mathematical model. When establishing the mathematical model of the motor, the motor parameters under the running state of the motor are used as the basis, so it is necessary to calculate and identify the motor parameters to lay a good parameter foundation for the subsequent establishment of the motor mathematical model.

[0003] The patent application with publication number CN112234897A discloses a permanent magnet synchronous motor parameter identification method, identification device and identification system. It automatically sends multiple groups of direct-axis current and quadrature-axis current to the permanent magnet synchronous motor to traverse the axisymmetric region of adjacent quadrants in the axis coordinate system, and automatically obtains the corresponding direct-axis voltage and quadrature-axis voltage to calculate the rotor permanent magnet flux for subsequent calling. It does not need to perform multiple tests, avoids the data processing error phenomenon of operation errors in multiple tests, and realizes the effect of accurately obtaining the permanent magnet synchronous motor parameters with simple operation. The existing motor parameter identification method usually needs to apply excitation signals to the motor for a long time, and combines a single-dimensional parameter setting method to identify the motor parameters. This long-time excitation signal application method can easily cause uncontrollable thermal effects, mechanical vibrations and potential electromagnetic interference in the motor, thereby affecting the stability of the motor operating state, reducing the safety and reliability of the parameter identification process, and the single-dimensional setting method can cause the motor parameter identification algorithm to be unstable on different performance calculation platforms, thereby causing low identification accuracy and calculation efficiency, which is not conducive to accurate identification of motor parameters.

[0004] In view of this, the present application provides a motor parameter identification method based on limited-width rectangular pulse excitation to solve the above problems. SUMMARY

[0005] In order to overcome the above-mentioned defects of the prior art and achieve the above-mentioned purpose, the present application provides the following technical scheme: a motor parameter identification method based on limited-width rectangular pulse excitation, comprising: S01: set the pulse width and pulse amplitude of the limited-width rectangular pulse according to the shortest response time and the rated voltage, and generate a pulse signal; S02: Determine the sampling period and sampling time of the motor under test, collect the dynamic parameters of the motor under test at the sampling time, and compare the coverage duration with the pulse width to determine whether to enter the recursive calculation mode; if the recursive calculation mode is entered, execute S03; if the recursive calculation mode is not entered, repeat S02. S03: Based on the static setting principle or the dynamic adjustment principle, initialize the characteristic parameters of the motor under test. The characteristic parameters include the regression vector and the parameter vector. Combine the characteristic parameters, dynamic parameters and the recursive least squares method to calculate the steady-state amplification factor and time constant of the motor under test at the sampling time. S04: Obtain the identification time and working status of the motor under test. The working status includes the stopped rotation state and the continuous rotation state. Based on the requirement satisfaction rule, analyze the identification time and working status to determine whether to execute the excitation response output operation. If the excitation response output operation is executed, execute S05; if the excitation response output operation is not executed, execute S02. S05: Output the steady-state amplification factor and time constant of the motor under test at standard time, and generate motor parameter identification results.

[0006] Furthermore, the method for generating pulse signals is as follows: Initialize the width and amplitude of the finite-width rectangular pulse, denoted as the initial width and initial amplitude; Find the rated voltage of the motor under test, take half of the rated voltage as the voltage unit, and assign a voltage unit to the initial amplitude to generate the pulse amplitude. Find the response time of the motor under test when it starts normally under A input signals, and record the minimum response time as the shortest response time; The shortest response time is rounded to the nearest integer to generate a width unit, and then an additional width unit is assigned to the initial width to generate the pulse width.

[0007] Furthermore, the method for determining the sampling period and sampling time is as follows: The number of digits after the decimal point in the pulse width is counted and recorded as the effective value; When the effective value is 0, the pulse width is doubled to generate the sampling period; When the effective value is greater than 0, all digits after the decimal point in the pulse width are removed, and the remaining part of the pulse width is doubled to generate the sampling period; The moment when the pulse signal is applied to the motor under test is recorded as the start time. Starting from the start time, B sampling moments are marked at intervals within the sampling period, based on a preset interval length.

[0008] Furthermore, the dynamic parameters include rotational speed and rotor position values; the rotational speed and rotor position values ​​are acquired by a speed sensor and an angle sensor, respectively.

[0009] Furthermore, the method for determining whether to enter the recursive calculation mode is as follows: The duration from the start time to the current time is calculated and recorded as the coverage duration. When the coverage duration is greater than or equal to the pulse width, it is determined that the recursive calculation mode is entered; If the coverage duration is less than the pulse width, it is determined that the recursive calculation mode will not be entered.

[0010] Furthermore, the static setting principle is: use the evaluation value as the basis for initializing the parameter vector; Under the static setting principle, the method for initializing the regression vector and parameter vector is as follows: The parameter vector is initialized based on the evaluation values ​​of the steady-state amplification factor and the time constant. The expression for the parameter vector is: ; In the formula, For parameter vectors, This is the evaluation value for the steady-state amplification factor. This is an evaluation value for the time constant; The regression vector is initialized based on the pulse width, pulse amplitude, and rotational speed of the pulse signal; The expression for the regression vector is: ; In the formula, For the regression vector, The pulse width. The pulse amplitude. This represents the rotational speed value.

[0011] Furthermore, the principle of dynamic adjustment is: use the rated value as the basis for initializing the parameter vector; Under the principle of dynamic adjustment, the method for initializing the regression vector and parameter vector is as follows: The rated voltage, rated current, rated speed, rated inductance, and rated resistance of the motor under test are retrieved. The rated inductance is increased by a preset inductance expansion range to obtain the real-time inductance. The rated resistance is increased by a preset resistance expansion range to obtain the real-time resistance. Based on the rated voltage, rated current, rated speed, real-time inductance, and real-time resistance, the adjustment values ​​for the steady-state amplification factor and the time constant are generated, and the parameter vector of the motor under test is initialized. The expression for the adjustment value of the steady-state amplification factor is: ; In the formula, This is the adjustment value for the steady-state amplification factor. Rated voltage, Rated current, Rated speed; The expression for the adjustment value of the time constant is: ; In the formula, This is the adjustment value for the time constant. For real-time inductance, For real-time resistance; The expression for the parameter vector is: ; The regression vector is initialized based on the pulse width, pulse amplitude, and rotational speed of the pulse signal.

[0012] Furthermore, the method for calculating the steady-state gain and time constant is as follows: By combining the parameter vector, regression vector, and rotor position value at the sampling time, the prior error of the motor under test at the sampling time is calculated. Initialize the covariance matrix, calculate the gain vector of the motor under test at the sampling time, and continuously update the parameter vector and covariance matrix of the motor under test at the sampling time. By back-calculating the parameter vector and covariance matrix at the sampling time, the steady-state amplification factor and time constant of the motor under test at the sampling time can be obtained.

[0013] Furthermore, the demand fulfillment rule is: when an incentive response occurs, execute the incentive response output operation; The method for determining whether to perform the stimulus response output operation is as follows: The moment when the pulse signal is fully applied to the motor under test is recorded as the identification start moment, and the duration between the identification start moment and the current moment is recorded as the identification duration. When the identification duration is greater than or equal to the duration of the pulse width, the motor under test exhibits an excitation response phenomenon. The rotational speed of the motor under test is detected by a speed sensor at the current moment. When the rotational speed is less than the rotational speed threshold, the working state is a stopped state, and the motor under test shows an excitation response phenomenon. The number of excitation response phenomena in the motor under test is counted one by one. When the number of excitation response phenomena is not 0, the excitation response output operation is executed. When the number of stimulus response phenomena is 0, it is determined that the stimulus response output operation will not be executed.

[0014] The technical effects and advantages of the motor parameter identification method based on finite-width rectangular pulse excitation of this invention are as follows: (1): Based on the shortest response time and rated voltage, this invention can set a pulse signal with a rectangular pulse of finite width, so that the pulse signal can be applied to the motor under test intermittently and instantaneously, ensuring that the pulse signal can interact with the motor under test in a very short time, avoiding the interference caused by the long-term excitation of the traditional excitation signal and the motor under test, thereby improving the stability and safety of motor parameter identification of the motor under test.

[0015] (2): This invention sets characteristic parameters by using static setting principles and dynamic adjustment principles. It can limit the parameters participating in the recursive least squares method from two aspects: empirical evaluation dimension and actual motor dimension. This provides two parallel calculation and identification logics for the accurate calculation of the steady-state amplification factor and time constant. This avoids the limitations of single-dimensional calculation and identification logic when running on microcontrollers with different performance, improves the compatibility between the motor parameter calculation and identification logic and microcontrollers with different performance, and lays a good foundation for the accurate identification of the steady-state amplification factor and time constant of the motor under test. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the motor parameter identification method based on finite-width rectangular pulse excitation provided in Embodiment 1 of the present invention. Figure 2 This is a velocity timing diagram of a noiseless experiment provided in Embodiment 2 of the present invention; Figure 3 This is a position time diagram of the noise-free experiment provided in Embodiment 2 of the present invention; Figure 4 This is a time diagram showing the steady-state amplification factor of the noise-free experiment provided in Embodiment 2 of the present invention; Figure 5 This is a time constant time diagram of the noise-free experiment provided in Embodiment 2 of the present invention; Figure 6 This is a velocity timing diagram of a noisy experiment provided in Embodiment 2 of the present invention; Figure 7 This is a location time diagram of a noisy experiment provided in Embodiment 2 of the present invention; Figure 8 This is a time-sharing diagram of the steady-state amplification factor in a noisy experiment provided in Embodiment 2 of the present invention; Figure 9 This is a time constant diagram of a noisy experiment provided in Embodiment 2 of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1: Please refer to Figure 1 As shown in this embodiment, the motor parameter identification method based on finite-width rectangular pulse excitation includes: S01: Based on the signal excitation criterion, set the signal parameters of the finite-width rectangular pulse, generate the pulse signal, and apply the pulse signal to the motor under test; A finite-width rectangular pulse is a pulse with a fixed duration that can cause excitation changes in the motor parameters of the motor under test. Since the finite-width rectangular pulse is not continuously applied to the motor under test along the time line, it needs to have a finite pulse width and pulse amplitude, i.e., signal parameters, so that the diverse parameters of the finite-width rectangular pulse can be represented. Specifically, the signal parameters include pulse width and pulse amplitude; where pulse width refers to the duration of a finite-width rectangular pulse acting on the motor under test, and pulse amplitude refers to the magnitude of the voltage applied to the motor under test by the finite-width rectangular pulse signal. When setting the pulse width and pulse amplitude, it is not possible to set them without any standards. The specific values ​​of the pulse width and pulse amplitude need to be determined under the constraints of the signal excitation criteria to ensure that the pulse signal applied to the motor under test can have a reasonable excitation effect on the operating state of the motor under test and cause sufficient change data to be collected. Specifically, the signal excitation criteria are as follows: convert the shortest response time into pulse width and reduce the rated voltage into pulse amplitude; where the shortest response time refers to the minimum time span during which the motor under test can respond to the pulse signal, and the rated voltage refers to the voltage of the motor under test during normal operation.

[0019] In this embodiment, after setting the pulse width and pulse amplitude of the finite-width rectangular pulse, the finite-width rectangular pulse will be transformed into a pulse signal, so that the pulse signal can be used as a pulse excitation directly applied to the motor under test. Specifically, the method for generating pulse signals is as follows: Initialize the width and amplitude of the finite-width rectangular pulse, denoted as the initial width and initial amplitude; Find the rated voltage of the motor under test, take half of the rated voltage as the voltage unit, and assign a voltage unit to the initial amplitude to generate the pulse amplitude. Find out the response time of the motor under test when it starts normally under the action of A input signals, compare the A response times one by one, and record the minimum response time as the shortest response time; The shortest response time is rounded to the nearest integer to generate a width unit, and then an additional width unit is assigned to the initial width to generate the pulse width.

[0020] By using the above-described method for generating pulse signals, a pulse signal with a defined pulse width and pulse amplitude can be generated. For example, when the rated voltage of the motor under test is 24V, the pulse amplitude of the pulse signal is 12V. When the width unit is 0.4S after rounding to the nearest integer with respect to the motor under test, the pulse width is 0.4S.

[0021] After obtaining the pulse width and pulse amplitude, the finite-width rectangular pulse is converted into a pulse signal. This allows the pulse signal to apply pulse excitation to the motor under test with the pulse width as the duration of the pulse excitation and the pulse amplitude as the excitation voltage. This drives the motor under test to undergo dynamic changes in motor parameters under the action of the pulse signal. The pulse signal can apply pulse signal to the motor under test in a very short time, avoiding signal interference caused by the pulse signal acting on the motor under test for a long time.

[0022] S02: Determine the sampling period and sampling time of the motor under test, collect the dynamic parameters of the motor under test at the sampling time, calculate the coverage duration of the dynamic parameters, and determine whether to enter the recursive calculation mode. The sampling period refers to the total time for the motor under test to perform a complete motor parameter identification operation. The process of a complete motor parameter identification operation includes, but is not limited to, the application of pulse signals, the acquisition, analysis and calculation of relevant parameters in the motor under test, and the identification of the steady-state amplification factor and time constant. The sampling time refers to the time point within the sampling period at which relevant parameters of the motor under test are collected due to the excitation change of the pulse signal. This enables the timed acquisition of data at each time point within the sampling period, ensuring the consistency and independence of the duration of each set of collected data.

[0023] When determining the sampling period and sampling time, it is necessary to first determine the sampling period of the motor under test, and then determine the sampling time according to a fixed time interval within the sampling period. When determining the sampling time, it is necessary to ensure that the duration between two adjacent sampling times can divide the duration of the sampling period equally, so that the duration span between any two adjacent sampling times in the sampling period is consistent. Specifically, the method for determining the sampling period and sampling time is as follows: The number of digits after the decimal point in the pulse width is counted and recorded as the effective value; When the effective value is 0, the pulse width does not contain any digits after the decimal point. Therefore, the pulse width is doubled to generate the sampling period. When the effective value is greater than 0, the pulse width contains at least one digit after the decimal point. In this case, all digits after the decimal point in the pulse width are removed, and the remaining part of the pulse width is doubled to generate the sampling period. The moment when the pulse signal is applied to the motor under test is recorded as the start time. Starting from the start time, B sampling moments are marked at intervals within the sampling period, based on a preset interval length.

[0024] It should be noted that the preset interval duration is used to specify the exact value of the interval duration between two adjacent sampling moments in the sampling period. This ensures that the duration span between any two adjacent sampling moments is equal, and that the excitation response parameters of the motor under test can be completely collected at each sampling moment. Specifically, the preset interval duration is obtained by averaging the duration spans of two complete excitation response parameter collections from a large number of historical motors under test.

[0025] Once the sampling period and sampling time are determined, the excitation response parameters of the motor under test at each sampling time can be used within the sampling period. These excitation response parameters are collectively referred to as dynamic parameters, so that the dynamic parameters can serve as the basis for subsequent motor parameter identification. Specifically, the dynamic parameters include rotational speed and rotor position. The rotational speed value refers to the rotational speed of the motor rotor at the sampling moment under the excitation of the pulse signal, and the rotor position value refers to the rotation angle of the motor rotor at the sampling moment under the excitation of the pulse signal. Thus, the excitation response parameters of the motor under test under the excitation of the pulse signal are represented in two dimensions. In this embodiment, the rotational speed value is collected in real time by a speed sensor inside the motor under test; the rotor position value is collected in real time by an angle sensor inside the motor under test.

[0026] Coverage duration refers to the time elapsed from when the pulse signal is applied to the motor under test until the dynamic parameters are collected. It can be summarized as the time it takes for the dynamic parameters of the motor under test to appear after being excited by the pulse signal. By analyzing the magnitude of the coverage duration, it can be determined whether the pulse signal at the current moment is complete and applied to the motor under test, and it can be used to determine whether the motor under test can enter the recursive calculation mode at the current moment. In this embodiment, the recursive calculation mode refers to the working mode after the motor under test has fully received the pulse signal and can meet the motor parameter identification operation.

[0027] Specifically, the method for determining whether to enter the recursive calculation mode is as follows: The duration from the start time to the current time is calculated and recorded as the coverage duration. The coverage duration is then compared with the pulse width. When the coverage duration is greater than or equal to the pulse width, the time when the pulse signal is applied to the motor under test exceeds the pulse width. The pulse signal can be fully applied to the motor under test, and the motor under test can collect and calculate the excitation response parameters generated by the pulse signal, and determine to enter the recursive calculation mode. When the coverage duration is less than the pulse width, the time the pulse signal is applied to the motor under test does not exceed the pulse width. The pulse signal cannot be fully applied to the motor under test, and the motor under test cannot collect and calculate the excitation response parameters generated by the pulse signal. Therefore, it is determined that the recursive calculation mode will not be entered.

[0028] It should be noted that when the coverage duration is greater than or equal to the pulse width, the pulse signal and the motor under test can be completely integrated, providing a complete and accurate environmental basis for the identification of the motor parameters. At this time, the recursive calculation mode can be entered to perform subsequent motor parameter identification operations. Conversely, when the coverage duration is less than the pulse width, the recursive calculation mode cannot be entered to perform subsequent motor parameter identification operations. In this case, step S02 is repeated until the recursive calculation mode can be entered.

[0029] S03: If entering the recursive calculation mode, based on the static setting principle or the dynamic adjustment principle, initialize the characteristic parameters of the motor under test, and calculate the steady-state amplification factor and time constant of the motor under test at the sampling time based on the characteristic parameters and dynamic parameters. Characteristic parameters refer to the parameters that affect the accuracy of motor parameter identification when the motor under test is used for motor parameter identification. Initializing the characteristic parameters of the motor under test can provide the most basic parameters for subsequent motor parameter identification calculations and lay the foundation for identifying motor parameters at multiple sampling times in different time periods. In this embodiment, the feature parameters include a regression vector and a parameter vector; wherein, the parameter vector represents the influence weight of the independent variable on the dependent variable in the regression model, the regression vector is used to construct the input part of the regression model, and after being combined with the parameter vector, a predicted value is generated, which is used to calculate the prior error in the recursive least squares method.

[0030] In order to improve the universality of the characteristic parameter initialization operation and avoid the limitations of a single initialization operation, the characteristic parameter initialization operation can be limited in two dimensions. This allows the characteristic parameters to be statically and dynamically set based on the experience evaluation of the same type of motor and the actual basic parameters of the motor under test. The initialization is constrained by the static setting principle and the dynamic adjustment principle. The static setting principle is a rule for custom initialization of the regression vector and parameter vector of the motor under test based on the experience evaluation of motors of the same type. This makes the regression vector and parameter vector of the motor under test under the static setting principle refer to the results of human experience. Specifically, the static setting principle is to use the evaluation value as the basis for initializing the parameter vector; so that the parameter vector set under the static setting principle can match the predicted and estimated values ​​of the same type of motor, thus achieving the static setting effect of the parameter vector.

[0031] Steady-state gain refers to the ratio between the change in output and the change in input when a constant signal is input to the motor and the signal has stabilized completely. It can be used to determine the magnitude of the change in motor speed after a pulse signal is applied. The time constant is a parameter that measures how fast the response speed of a motor changes. It defines the time required for the motor to reach 63.2% of its final steady-state value from its initial state, and can be used to judge how fast the motor speed changes after a pulse signal is applied.

[0032] Recursive least squares is an online parameter estimation algorithm that dynamically adjusts model parameters by iteratively updating and minimizing the sum of squared errors. It is suitable for real-time data processing and system identification. In this embodiment, the recursive principle of recursive least squares is used to recursively calculate and analyze the data collected by the motor under test at different sampling times, thereby obtaining the final steady-state amplification factor and time constant.

[0033] Under the static setting principle, the method for calculating the steady-state gain and time constant is as follows: The parameter vector is initialized based on the evaluation values ​​of the steady-state amplification factor and the time constant. The expression for the parameter vector is: ; In the formula, For parameter vectors, This is the evaluation value for the steady-state amplification factor. This is an evaluation value for the time constant; The regression vector is initialized based on the pulse width, pulse amplitude, and rotational speed of the pulse signal; The expression for the regression vector is: ; In the formula, For the regression vector, The pulse width. The pulse amplitude. This represents the rotational speed value; By combining the parameter vector, regression vector, and rotor position value at the sampling time, the prior error of the motor under test at the sampling time is calculated. The formula for calculating prior error is: ; In the formula, For the first The prior error at each sampling time, =1, 2...B, For the first The rotor position value at each sampling time. For the first The regression vector at each sampling time point, This is the transpose of the regression vector. For the first The parameter vector at each sampling time point; Initialize the covariance matrix, calculate the gain vector of the motor under test at the sampling time, and continuously update the parameter vector and covariance matrix of the motor under test at the sampling time. The formula for calculating the gain vector is: ; In the formula, For the first The gain vector at each sampling time. For the first The covariance matrix at each sampling time; The formula for updating the parameter vector is: ; In the formula, For the first The parameter vector at each sampling time point; The formula for updating the covariance matrix is: ; In the formula, For the first The covariance matrix at each sampling time point It is the identity matrix; By back-calculating the parameter vector and covariance matrix at the sampling time, the steady-state amplification factor and time constant of the motor under test at the sampling time can be obtained.

[0034] The dynamic adjustment principle is a rule for custom initialization of the regression vector and parameter vector of the motor under test based on the relevant parameters actually queried by the motor under test. This makes the regression vector and parameter vector of the motor under test under the dynamic adjustment principle refer to the actual results of the motor under test. Specifically, the dynamic adjustment principle is as follows: the rated value is used as the basis for initializing the parameter vector; so that the parameter vector set under the dynamic adjustment principle can match the actual situation of the motor under test, and realize the dynamic adjustment effect of the parameter vector.

[0035] Under the principle of dynamic adjustment, the method for calculating the steady-state gain and time constant is as follows: The rated voltage, rated current, rated speed, rated inductance, and rated resistance of the motor under test are retrieved. The rated inductance is increased by a preset inductance expansion margin to obtain the real-time inductance, and the rated resistance is increased by a preset resistance expansion margin to obtain the real-time resistance. The preset inductance expansion margin refers to the pre-set expansion ratio used to increase the rated inductance, and the preset resistance expansion margin refers to the pre-set expansion ratio used to increase the rated resistance. Since the actual inductance and resistance of the motor under test usually exceed the rated inductance and rated resistance by a certain margin, it is necessary to increase the rated inductance and rated resistance. For example, the preset inductance expansion margin is 8%, and the preset resistance expansion margin is 7%. Based on the rated voltage, rated current, rated speed, real-time inductance, and real-time resistance, the adjustment values ​​for the steady-state amplification factor and the time constant are generated, and the parameter vector of the motor under test is initialized. The expression for the adjustment value of the steady-state amplification factor is: ; In the formula, This is the adjustment value for the steady-state amplification factor. Rated voltage, Rated current, Rated speed; The expression for the adjustment value of the time constant is: ; In the formula, This is the adjustment value for the time constant. For real-time inductance, For real-time resistance; The expression for the parameter vector is: ; In the formula, For parameter vectors; The regression vector is initialized based on the pulse width, pulse amplitude, and rotational speed of the pulse signal; The expression for the regression vector is: ; In the formula, For the regression vector, The pulse width. The pulse amplitude. This represents the rotational speed value; By combining the parameter vector, regression vector, and rotor position value at the sampling time, the prior error of the motor under test at the sampling time is calculated. The formula for calculating prior error is: ; In the formula, For the first The prior error at each sampling time, =1, 2...B, For the first The rotor position value at each sampling time. For the first The regression vector at each sampling time point, This is the transpose of the regression vector. For the first The parameter vector at each sampling time point; Initialize the covariance matrix, calculate the gain vector of the motor under test at the sampling time, and continuously update the parameter vector and covariance matrix of the motor under test at the sampling time. The formula for calculating the gain vector is: ; In the formula, For the first The gain vector at each sampling time. For the first The covariance matrix at each sampling time; The formula for updating the parameter vector is: ; In the formula, For the first The parameter vector at each sampling time point; The formula for updating the covariance matrix is: ; In the formula, For the first The covariance matrix at each sampling time point It is the identity matrix; By back-calculating the parameter vector and covariance matrix at the sampling time, the steady-state amplification factor and time constant of the motor under test at the sampling time can be obtained.

[0036] It should be noted that, regardless of whether it is based on the static setting principle or the dynamic adjustment principle, the update of the parameter vector and covariance matrix of the motor under test at the sampling time can only represent the real-time situation of the motor under test at a certain sampling time. At this time, the steady-state amplification factor and time constant calculated by reverse calculation can only represent the specific values ​​of the motor under test at that sampling time, and are not the final steady-state amplification factor and time constant output.

[0037] S04: Obtain the identification duration and working status of the motor under test at the current moment. Based on the requirement satisfaction rule, analyze the identification duration and working status of the motor under test and determine whether to execute the excitation response output operation. After calculating the steady-state amplification factor and time constant of the motor under test at a certain sampling moment, it is necessary to collect and identify the identification time and working state of the motor under test under the excitation of the pulse signal. The identification time refers to the total time taken for the motor under test to receive the pulse signal and perform corresponding parameter acquisition and calculation. It can be used as the overall time for the motor under test to identify motor parameters. When the identification time exceeds a certain value, the motor under test has completely realized the calculation of steady-state amplification factor and time constant.

[0038] The working state refers to the result of the motor under test receiving a pulse signal and the corresponding change in the speed of the motor rotor. This can be used as the excitation effect of the motor under test on the pulse signal. Specifically, the working state includes the stopped rotation state and the continuous rotation state. When the working state is the stopped rotation state, it means that the motor under test has fully realized the excitation response of the pulse signal and realized the calculation of the steady-state amplification factor and time constant.

[0039] After collecting the identification duration and working status, the identification duration and working status can be analyzed, and based on the analysis results, it can be determined whether to execute the excitation response output operation, thereby outputting the final steady-state amplification factor and time constant.

[0040] When analyzing and judging the identification time and working status, the analysis needs to be carried out under the constraints of the requirement satisfaction rules; Specifically, the requirement fulfillment rule is: when an incentive response occurs, execute the incentive response output operation.

[0041] Specifically, the method for determining whether to perform the stimulus response output operation is as follows: The moment when the pulse signal is fully applied to the motor under test is recorded as the identification start moment, the duration from the identification start moment to the current moment is recorded as the identification duration, and the identification duration is compared with the pulse width. When the identification duration is greater than or equal to the pulse width, it indicates that the motor under test can fully excite and respond to the pulse signal. At this time, the motor under test can output the required motor parameters, and the motor under test exhibits an excitation response phenomenon. The rotational speed of the motor under test is detected by a speed sensor at the current moment, and the rotational speed value is compared with a rotational speed threshold. The rotational speed threshold is used to limit the minimum value of the rotational speed when the motor parameters can be output, and serves as a direct basis for determining whether the rotor of the motor under test has stopped rotating. The rotational speed threshold is usually very small, for example, the rotational speed threshold is 3 r / min or 5 r / min. When the rotational speed value is less than the rotational speed threshold, it indicates that the rotor rotational speed of the motor under test is almost stopped or has stopped. At this time, the motor under test can output the required motor parameters. The working state is the stopped rotation state, and the motor under test has exhibited excitation response phenomenon. The number of excitation response phenomena in the motor under test is counted one by one. When the number of excitation response phenomena is not 0, the excitation response output operation is executed. When the number of stimulus response phenomena is 0, it is determined that the stimulus response output operation will not be executed.

[0042] In this embodiment, the number of excitation response phenomena is 0, 1, or 2. When the motor under test is at any sampling time, as long as an excitation response phenomenon occurs, it can be determined that the motor under test can output the steady-state amplification factor and time constant, and S05 is executed. When no excitation response phenomenon occurs, S02 is executed repeatedly. S05: Determine the standard time from the sampling time, output the steady-state amplification factor and time constant of the standard time, and generate the motor parameter identification results; The standard time refers to the sampling time corresponding to the excitation response output operation, so that the steady-state amplification factor and time constant calculated under the standard time can be used as the true and accurate motor parameters of the motor under test, thereby achieving the accurate identification of motor parameters; Therefore, the steady-state amplification factor and time constant at the standard time are calculated from the sampling time corresponding to the excitation response output operation.

[0043] After obtaining the steady-state amplification factor and time constant at the standard moment, the obtained steady-state amplification factor and time constant can be used as the result of motor parameter identification of the motor under test. This allows the steady-state amplification factor and time constant at the standard moment to serve as the data basis for subsequent accurate mathematical model of the motor under test, enabling high-precision speed regulation or position control operations.

[0044] Example 2: Please refer to Figures 2-9As shown, the parts not described in detail in this embodiment are described in Embodiment 1. Based on the motor parameter identification method based on finite-width rectangular pulse excitation, it is applied to a specific Maxon-RE30 DC motor, making this DC motor an experimental motor with a steady-state amplification factor of 33.6 and a time constant of 0.018. The rectangular pulse width is set to 500 milliseconds. =0.5 seconds, the voltage is 50% of the rated voltage, that is =12V, sampling period is 1 second, and 10 sampling times are set at 0.1-second intervals within the sampling period. At 0.5 seconds, the recursive least squares method is executed to calculate the steady-state amplification factor and time constant. To better demonstrate the accuracy and adaptability of the steady-state amplification factor and time constant calculations in this embodiment, noiseless and noisy experiments were conducted on the experimental motor. In the noisy experiment, random noise within 10% of the steady-state value was added to the rotational speed and rotor position values ​​of the experimental motor. The rotational speed, rotor position, steady-state amplification factor, and time constant were collected at 10 sampling moments within 1 second. Based on the experimental results of the experimental motor, the experimental data from the noiseless and noisy experiments were plotted as required. Specifically, the graphs for both noiseless and noisy experiments include velocity time plots, position time plots, steady-state magnification time plots, and time constant time plots; As shown in the above figures, at 0.5 seconds, the recursive least squares method is initiated to calculate the steady-state amplification factor and time constant. At the end of the first second, the calculated steady-state amplification factor is 33.77, and the calculated time constant is 0.0184. Furthermore, the calculation results under noisy conditions have an error of 0.51% in the steady-state amplification factor and an error of 2.22% in the time constant compared to the calculation results under noise-free conditions. Therefore, it can be seen that the process of calculating the steady-state amplification factor and time constant in the above embodiment has good noise reduction capabilities and does not require additional filtering processing of the rotation speed value and rotor position value at the sampling time.

[0045] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for identifying motor parameters based on finite-width rectangular pulse excitation, characterized in that, include: S01: Based on the shortest response time and rated voltage, set the pulse width and pulse amplitude of the finite-width rectangular pulse to generate a pulse signal; S02: Determine the sampling period and sampling time of the motor under test, collect the dynamic parameters of the motor under test at the sampling time, and compare the coverage duration with the pulse width to determine whether to enter the recursive calculation mode; if the recursive calculation mode is entered, execute S03; if the recursive calculation mode is not entered, repeat S02. S03: Based on the static setting principle or the dynamic adjustment principle, initialize the characteristic parameters of the motor under test. The characteristic parameters include the regression vector and the parameter vector. Combine the characteristic parameters, dynamic parameters and the recursive least squares method to calculate the steady-state amplification factor and time constant of the motor under test at the sampling time. S04: Obtain the identification time and working status of the motor under test. The working status includes the stopped rotation state and the continuous rotation state. Based on the requirement satisfaction rule, analyze the identification time and working status to determine whether to execute the excitation response output operation. If the excitation response output operation is executed, execute S05; if the excitation response output operation is not executed, execute S02. S05: Output the steady-state amplification factor and time constant of the motor under test at standard time, and generate motor parameter identification results.

2. The method for motor parameter identification based on finite-width rectangular pulse excitation according to claim 1, characterized in that, The method for generating pulse signals is as follows: Initialize the width and amplitude of the finite-width rectangular pulse, denoted as the initial width and initial amplitude; Find the rated voltage of the motor under test, take half of the rated voltage as the voltage unit, and assign a voltage unit to the initial amplitude to generate the pulse amplitude. Find the response time of the motor under test when it starts normally under A input signals, and record the minimum response time as the shortest response time; The shortest response time is rounded to the nearest integer to generate a width unit, and then an additional width unit is assigned to the initial width to generate the pulse width.

3. The method for motor parameter identification based on finite-width rectangular pulse excitation according to claim 2, characterized in that, The method for determining the sampling period and sampling time is as follows: The number of digits after the decimal point in the pulse width is counted and recorded as the effective value; When the effective value is 0, the pulse width is doubled to generate the sampling period; When the effective value is greater than 0, all digits after the decimal point in the pulse width are removed, and the remaining part of the pulse width is doubled to generate the sampling period; The moment when the pulse signal is applied to the motor under test is recorded as the start time. Starting from the start time, B sampling moments are marked at intervals within the sampling period, based on a preset interval length.

4. The motor parameter identification method based on finite-width rectangular pulse excitation according to claim 3, characterized in that, The dynamic parameters include rotational speed and rotor position; the rotational speed and rotor position are acquired by a speed sensor and an angle sensor, respectively.

5. The method for motor parameter identification based on finite-width rectangular pulse excitation according to claim 4, characterized in that, The method for determining whether to enter the recursive calculation mode is as follows: The duration from the start time to the current time is calculated and recorded as the coverage duration. When the coverage duration is greater than or equal to the pulse width, it is determined that the recursive calculation mode is entered; If the coverage duration is less than the pulse width, it is determined that the recursive calculation mode will not be entered.

6. The method for motor parameter identification based on finite-width rectangular pulse excitation according to claim 5, characterized in that, The static setting principle is: use the evaluation value as the basis for initializing the parameter vector; Under the static setting principle, the method for initializing the regression vector and parameter vector is as follows: The parameter vector is initialized based on the evaluation values ​​of the steady-state amplification factor and the time constant. The expression for the parameter vector is: ； In the formula, For parameter vectors, This is the evaluation value for the steady-state amplification factor. This is an evaluation value for the time constant; The regression vector is initialized based on the pulse width, pulse amplitude, and rotational speed of the pulse signal; The expression for the regression vector is: ； In the formula, For the regression vector, The pulse width. The pulse amplitude. This represents the rotational speed value.

7. The method for motor parameter identification based on finite-width rectangular pulse excitation according to claim 6, characterized in that, The principle of dynamic adjustment is: use the rated value as the basis for initializing the parameter vector; Under the principle of dynamic adjustment, the method for initializing the regression vector and parameter vector is as follows: The rated voltage, rated current, rated speed, rated inductance, and rated resistance of the motor under test are retrieved. The rated inductance is increased by a preset inductance expansion range to obtain the real-time inductance. The rated resistance is increased by a preset resistance expansion range to obtain the real-time resistance. Based on the rated voltage, rated current, rated speed, real-time inductance, and real-time resistance, the adjustment values ​​for the steady-state amplification factor and the time constant are generated, and the parameter vector of the motor under test is initialized. The expression for the adjustment value of the steady-state amplification factor is: ； In the formula, This is the adjustment value for the steady-state amplification factor. Rated voltage, Rated current, Rated speed; The expression for the adjustment value of the time constant is: ； In the formula, This is the adjustment value for the time constant. For real-time inductance, For real-time resistance; The expression for the parameter vector is: ； The regression vector is initialized based on the pulse width, pulse amplitude, and rotational speed of the pulse signal.

8. The method for motor parameter identification based on finite-width rectangular pulse excitation according to claim 7, characterized in that, The method for calculating steady-state gain and time constant is as follows: By combining the parameter vector, regression vector, and rotor position value at the sampling time, the prior error of the motor under test at the sampling time is calculated. Initialize the covariance matrix, calculate the gain vector of the motor under test at the sampling time, and continuously update the parameter vector and covariance matrix of the motor under test at the sampling time. By back-calculating the parameter vector and covariance matrix at the sampling time, the steady-state amplification factor and time constant of the motor under test at the sampling time can be obtained.

9. The method for motor parameter identification based on finite-width rectangular pulse excitation according to claim 8, characterized in that, The requirement fulfillment rule is: when an incentive response phenomenon occurs, the incentive response output operation is executed; The method for determining whether to perform the stimulus response output operation is as follows: The moment when the pulse signal is fully applied to the motor under test is recorded as the identification start moment, and the duration between the identification start moment and the current moment is recorded as the identification duration. When the identification duration is greater than or equal to the duration of the pulse width, the motor under test exhibits an excitation response phenomenon. The rotational speed of the motor under test is detected by a speed sensor at the current moment. When the rotational speed is less than the rotational speed threshold, the working state is a stopped state, and the motor under test shows an excitation response phenomenon. The number of excitation response phenomena in the motor under test is counted one by one. When the number of excitation response phenomena is not 0, the excitation response output operation is executed. When the number of stimulus response phenomena is 0, it is determined that the stimulus response output operation will not be executed.

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