A Sensorless Brushless Motor Control Method and System Based on State Observer

Abstract

This invention relates to the field of brushless motor control technology, specifically a sensorless brushless motor control method and system based on a state observer. The method includes: detecting the current of the brushless motor under test to obtain an original operating current set; constructing an original observation model of the state observer; using the original observation model to obtain an observed operating current set; calculating the observation error value between the observed operating current set and the original operating current set; determining whether the observation error value is greater than a minimum error value; if it is, adjusting the original observation model to obtain an adjusted observation model; and recalculating the observation error value until the observation error value is not less than the minimum error value, thus obtaining a target observation model; and calculating the observed rotor position angle and observed rotor speed based on the target observation model. This invention can improve the accuracy of rotor parameter detection and the stability of motor control during brushless motor control.

Description

Technical Field

[0001] This invention relates to the field of brushless motor control technology, and in particular to a sensorless brushless motor control method and system based on a state observer. Background Technology

[0002] Brushless motors, as a high-performance motor system, are widely used in aerospace, electric vehicles, industrial automation, and home appliances due to their advantages such as high efficiency, high power density, low noise, and long lifespan. However, the control of brushless motors usually relies on position sensors, such as Hall sensors, to obtain rotor position information in order to achieve precise commutation control. This sensor-dependent approach has some limitations, such as increased sensor installation costs, reduced reliability, increased size, and limited applicability in harsh environments. Therefore, in some application environments, a sensorless brushless motor control method is needed to replace the sensor-based brushless motor control method.

[0003] Current sensorless brushless motor control methods mainly rely on back EMF detection. However, this method suffers from low accuracy in detecting rotor position and speed due to the weak back EMF signal when the motor is at low speed or during startup. Furthermore, the stability of the control system decreases when motor parameters change or the load changes abruptly. Summary of the Invention

[0004] This invention provides a sensorless brushless motor control method and system based on a state observer, the main purpose of which is to improve the accuracy of rotor parameter detection and the stability of motor control during brushless motor control.

[0005] To achieve the above objectives, the present invention provides a sensorless brushless motor control method based on a state observer, comprising:

[0006] Receive motor control commands and start the brushless motor under test based on the motor control commands, wherein the brushless motor under test has built-in current detector, voltage detector, resistance detector, inductance detector and state observer;

[0007] The brushless motor under test is subjected to current detection using a current sensor to obtain an original operating current set. The original operating current set includes multiple original operating currents, and each original operating current includes an original vertical current and an original parallel current.

[0008] Construct the original observation model of the state observer;

[0009] Using the original observation model, the state parameters of the brushless motor under test are calculated to obtain the observed operating current set, wherein the number of observed operating currents in the observed operating current set is the same as the number of original operating currents in the original operating current set.

[0010] Based on the observed operating current set and the original operating current set, an observation error analysis is performed to obtain the observation error value, and it is determined whether the observation error value is greater than the preset minimum error value.

[0011] If the observation error value is greater than the minimum error value, the original observation model is adjusted to obtain an adjusted observation model.

[0012] The adjusted observation model is used as the original observation model. The process of calculating the state parameters of the brushless motor under test using the original observation model is repeated until the observation error value is not greater than the minimum error value. The original observation model at this time is then recorded as the target observation model.

[0013] Based on the target observation model, the observed rotor position angle and observed rotor speed are calculated, and sensorless brushless motor control based on the observed rotor position angle and observed rotor speed is completed.

[0014] Optionally, the step of performing current detection on the brushless motor under test based on a current sensor to obtain the original operating current set includes:

[0015] Under a preset current detection period, the current signal is monitored using the current detector to obtain a continuous operating current, wherein the continuous operating current is a current signal that changes continuously under the current detection period.

[0016] The sampling period of the state observer is obtained, and based on the sampling period, discrete current is collected in the continuous operating current to obtain the original operating current set.

[0017] Optionally, the original observation model for constructing the state observer includes:

[0018] Set the current current variable and the historical current variable, wherein the current current variable includes: the current vertical current variable and the current parallel current variable, and the historical current variable includes: the historical vertical current variable and the historical parallel current variable;

[0019] Based on the sampling period, current current variable, and historical current variable, an original observation model is constructed, wherein the original observation model is expressed as:

[0020]

[0021] in, Represents the original observation model. Indicates the current vertical current variable. Represents historical vertical current variables. Indicates the sampling period. This represents the preset inductance variable. This represents the preset vertical voltage variable. This indicates the preset resistance variable. This represents the preset initial vertical control factor. Indicates the current parallel current variable. Represents historical parallel current variables. The table shows the preset parallel voltage variables. This represents the preset original parallel control factor.

[0022] Optionally, the step of using the original observation model to calculate the state parameters of the brushless motor under test and obtaining the observed operating current set includes:

[0023] In the step of detecting the current of the brushless motor under test based on the current sensor, the synchronous parameters of the brushless motor under test are detected by the voltage sensor, resistance sensor and inductance sensor to obtain a synchronous motor parameter set. The synchronous motor parameter set includes multiple synchronous motor parameters, including: synchronous motor resistance, synchronous motor inductance, synchronous vertical voltage and synchronous parallel voltage.

[0024] If the step of performing synchronization parameter detection on the brushless motor under test is the first time performing synchronization parameter detection, then the preset zero values ​​are recorded as historical vertical current and historical parallel current respectively.

[0025] If the step of performing synchronization parameter detection on the brushless motor under test is not the first time performing synchronization parameter detection, then query the historical vertical current and historical parallel current.

[0026] Synchronous motor parameters are extracted sequentially from the synchronous motor parameter set. The synchronous motor parameters, historical vertical current, and historical parallel current are substituted into the original observation model to obtain the observed operating current, wherein the observed operating current includes the observed vertical current and the observed parallel current.

[0027] The observed operating currents are summarized to obtain the observed operating current set.

[0028] Optionally, the step of performing observation error analysis based on the observed operating current set and the original operating current set to obtain the observation error value includes:

[0029] Based on the observed operating current set and the original operating current set, effective current data analysis is performed to obtain the effective current error factor set and the effective fluctuation weight set.

[0030] Based on the effective current error factor set and the effective fluctuation weight set, the observation error value is calculated using the following formula:

[0031]

[0032] in, This represents the observation error value. This indicates the number of effective current error factors in the effective current error factor set or the number of effective fluctuation weights in the effective fluctuation weight set. Represents the first in the effective fluctuation weight set One effective fluctuation weight, Represents the first in the effective current error factor set One effective current error factor.

[0033] Optionally, the step of performing effective current data analysis based on the observed operating current set and the original operating current set to obtain an effective current error factor set and an effective fluctuation weight set includes:

[0034] Record the completion time of the step of detecting the current of the brushless motor under test based on the current sensor;

[0035] The observed operating current and the original operating current corresponding to the observed operating current are extracted sequentially from the observed operating current set and the original operating current set, and the current acquisition time of the observed operating current and the original operating current is obtained. The time fluctuation weight between the detection completion time and the current acquisition time is calculated.

[0036] Calculate the error factor per unit current;

[0037] If it is confirmed that the unit current error factor is not greater than the preset controllable error factor, then the unit current error factor and the time fluctuation weight are respectively recorded as the effective current error factor and the effective fluctuation weight.

[0038] The effective current error factor and the effective fluctuation weight are summarized respectively to obtain the effective current error factor set and the effective fluctuation weight set.

[0039] Optionally, the calculation of the unit current error factor includes:

[0040] Based on the observed operating current and the original operating current, the unit current error factor is calculated, wherein the unit current error factor is expressed as:

[0041]

[0042] in, Indicates the error factor per unit current. This represents the initial vertical current in the initial operating current. This represents the observed vertical current in the observed operating current. This represents the original parallel current in the original operating current. This represents the observed parallel current in the observed operating current.

[0043] Optionally, adjusting the original observation model to obtain an adjusted observation model includes:

[0044] An adjustment amplitude factor is set based on the sampling period, wherein the adjustment amplitude factor is expressed as:

[0045]

[0046] Among them, the Indicates the adjustment amplitude factor. This represents a preset selection constant;

[0047] Based on the adjustment amplitude factor, the vertical control factor and the horizontal control factor are calculated using the following formula:

[0048]

[0049]

[0050] in, This indicates adjustment of the vertical control factor. Indicates the adjustment of parallel control factors;

[0051] The original vertical control factor and the original parallel control factor in the original observation model are replaced by the adjusted vertical control factor and the adjusted parallel control factor, respectively, to obtain the adjusted observation model.

[0052] Optionally, calculating the observed rotor position angle and observed rotor speed based on the target observation model includes:

[0053] Identify the target vertical control factor and the target parallel control factor in the target observation model;

[0054] The vertical back electromotive force in the target vertical control factor and the parallel back electromotive force in the target parallel control factor are extracted using a preset low-pass filter.

[0055] Based on the vertical back electromotive force and the parallel back electromotive force, the observed rotor position angle and the observed rotor speed are calculated, wherein the observed rotor position angle and the observed rotor speed are respectively expressed as:

[0056]

[0057]

[0058] in, Indicates the observed rotor position angle. Represents the arctangent function in the four quadrants. Represents the vertical back electromotive force. This represents the parallel back electromotive force. Indicates the observed rotor speed. This represents the preset back electromotive force constant.

[0059] To achieve the above objectives, the present invention also provides a sensorless brushless motor control system based on a state observer, comprising:

[0060] The raw current acquisition module is used to receive motor control commands and start the brushless motor under test based on the motor control commands. The brushless motor under test has a built-in current sensor, voltage sensor, resistance sensor, inductance sensor and state observer. The current sensor detects the current of the brushless motor under test to obtain a raw operating current set. The raw operating current set includes multiple raw operating currents, and each raw operating current includes a raw vertical current and a raw parallel current.

[0061] The motor current observation module is used to construct the original observation model of the state observer. Using the original observation model, the state parameters of the brushless motor under test are calculated to obtain the observed operating current set. The number of observed operating currents in the observed operating current set is the same as the number of original operating currents in the original operating current set.

[0062] The observation model adjustment module is used to perform observation error analysis based on the observed operating current set and the original operating current set, obtain the observation error value, and determine whether the observation error value is greater than a preset minimum error value. If the observation error value is greater than the minimum error value, the original observation model is adjusted to obtain an adjusted observation model.

[0063] The rotor parameter calculation module is used to take the adjustment observation model as the original observation model, return to the step of using the original observation model to calculate the state parameters of the brushless motor under test, until the observation error value is not greater than the minimum error value, and record the original observation model at this time as the target observation model. Based on the target observation model, the observed rotor position angle and observed rotor speed are calculated.

[0064] To address the above problems, the present invention also provides an electronic device, the electronic device comprising:

[0065] Memory, storing at least one instruction;

[0066] The processor executes the instructions stored in the memory to implement the sensorless brushless motor control method based on the state observer described above.

[0067] To address the aforementioned problems, the present invention also provides a computer-readable storage medium storing at least one instruction, which is executed by a processor in an electronic device to implement the aforementioned sensorless brushless motor control method based on a state observer.

[0068] To address the problems described in the background section, this invention first starts the brushless motor under test (BMT). This BMT does not contain position or speed sensors, thus reducing the cost, complexity, and failure risk of controlling the BMT. Next, current is detected in the BMT using a current sensor to obtain the original operating current set. This step allows real-time acquisition of the motor's current information, including vertical and parallel currents, providing foundational data for subsequent state estimation. Then, parameters such as resistance and inductance in the BMT are detected, and an initial observation model for the state observer is constructed based on these parameters. This model describes the dynamic characteristics of the motor during operation, providing a specific calculation method for subsequent estimation of rotor position and rotor speed. Furthermore, using the initial observation model, state parameters of the BMT are calculated. The system observes the operating current set and calculates the observation error between the original and observed operating current sets. Based on this error, it dynamically adjusts the original observation model. This adjustment method progressively modifies the original observation model of the state observer, ensuring it remains in an optimal state and achieving high-precision tracking of the motor's operating state. This approach not only improves the accuracy of rotor position and speed detection but also enhances the stability of motor control. Through this dynamic adjustment mechanism, the final target observation model can accurately estimate the rotor position angle and speed, especially during low-speed operation and startup, where traditional methods often struggle to accurately obtain rotor position information. This method effectively solves this problem by continuously adjusting the original observation model, achieving stable control across the entire speed range. Therefore, this invention improves the accuracy of rotor parameter detection and the stability of motor control in brushless motor control. Attached Figure Description

[0069] Figure 1 This is a flowchart illustrating a sensorless brushless motor control method based on a state observer according to an embodiment of the present invention.

[0070] Figure 2 This is a functional block diagram of a sensorless brushless motor control system based on a state observer provided in an embodiment of the present invention;

[0071] Figure 3 This is a schematic diagram of the structure of an electronic device that implements the state observer-based sensorless brushless motor control method according to an embodiment of the present invention.

[0072] Explanation of reference numerals in the attached figures:

[0073] 10. Electronic device; 11. Processor; 12. Memory; 13. Bus.

[0074] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0075] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0076] This application provides a sensorless brushless motor control method based on a state observer. The executing entity of the sensorless brushless motor control method based on the state observer includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the sensorless brushless motor control method based on the state observer can be executed by software or hardware installed on a terminal device or a server device, and the software can be a blockchain platform. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster.

[0077] Reference Figure 1 The diagram shown is a flowchart illustrating a sensorless brushless motor control method based on a state observer according to an embodiment of the present invention. In this embodiment, the sensorless brushless motor control method based on a state observer includes:

[0078] S1. Receive motor control command, and start the brushless motor under test based on the motor control command, wherein the brushless motor under test has a built-in current sensor, voltage sensor, resistance sensor, inductance sensor and state observer.

[0079] Understandably, the motor control command refers to a manually initiated command to control the brushless motor. This command includes the model of the brushless motor to be controlled. The brushless motor refers to a motor without brushes and a commutator. Compared to traditional motors, it can be driven by electronic commutation, thus offering advantages such as high efficiency, long lifespan, and low noise. The brushless motor under test refers to the brushless motor to be controlled as included in the motor control command. The current sensor is a device that measures the operating current of the brushless motor. The voltage sensor is a device that measures the operating voltage of the brushless motor. The resistance sensor is a device that measures the resistance of the brushless motor. Since the resistance of the brushless motor changes with increasing operating temperature, it is necessary to monitor the resistance in real time using a resistance sensor. The inductance sensor is a device that measures the inductance of the brushless motor. The state observer is a device that estimates the rotor position and rotor speed of the brushless motor based on mathematical model algorithms and measurable parameters of the brushless motor, such as current and voltage.

[0080] Furthermore, in traditional motor control systems, position sensors and speed sensors, such as Hall sensors and encoders, are usually required to detect the position and speed of the motor rotor. However, position sensors and speed sensors increase the cost, complexity, and failure risk of the system. Therefore, the rotor position and speed can be indirectly estimated by using information such as motor current and voltage, thereby achieving motor control while reducing motor control costs and failure risks.

[0081] S2. Based on the current sensor, the brushless motor under test is current detected to obtain the original operating current set, wherein the original operating current set includes multiple original operating currents, and each original operating current includes an original vertical current and an original parallel current.

[0082] Understandably, the original operating current set refers to the collection of original operating currents, the original operating current refers to the current value of the brushless motor during operation, the original vertical current refers to the current whose direction is perpendicular to the direction of the rotor magnetic field, and the original parallel current refers to the current whose direction is parallel to the direction of the rotor magnetic field.

[0083] It needs to be explained that the signal obtained by the current sensor when detecting the brushless motor under test is a continuously changing current signal. However, in the actual brushless motor control system, it is not possible to directly process the continuous current signal. Therefore, it is necessary to discretize the continuous current signal to obtain the original operating current set. Discretization refers to extracting discrete current signals from the continuous current signal.

[0084] Specifically, the current detection of the brushless motor under test based on the current sensor to obtain the original operating current set includes:

[0085] Under a preset current detection period, the current signal is monitored using the current detector to obtain a continuous operating current, wherein the continuous operating current is a current signal that changes continuously under the current detection period.

[0086] The sampling period of the state observer is obtained, and based on the sampling period, discrete current is collected in the continuous operating current to obtain the original operating current set.

[0087] Understandably, the current detection period refers to the duration of monitoring the current signal of the brushless motor, the continuous operating current refers to the continuously changing current signal, the sampling period refers to the time interval between two original operating currents collected in the continuous operating current, and the specific value of the sampling period can be set manually, and the discrete current acquisition refers to determining an original operating current at every current sampling interval in the continuous operating current.

[0088] S3. Construct the original observation model of the state observer.

[0089] It is clear that the original observation model refers to the data model by which the state observer estimates the parameters of the brushless motor under test. The rotor position and rotor speed of the brushless motor under test can be estimated through this original observation model.

[0090] In detail, the original observation model for constructing the state observer includes:

[0091] Set the current current variable and the historical current variable, wherein the current current variable includes: the current vertical current variable and the current parallel current variable, and the historical current variable includes: the historical vertical current variable and the historical parallel current variable;

[0092] Based on the sampling period, current current variable, and historical current variable, an original observation model is constructed, wherein the original observation model is expressed as:

[0093]

[0094] in, Represents the original observation model. Indicates the current vertical current variable. Represents historical vertical current variables. Indicates the sampling period. This represents the preset inductance variable. This represents the preset vertical voltage variable. This indicates the preset resistance variable. This represents the preset initial vertical control factor. Indicates the current parallel current variable. Represents historical parallel current variables. The table shows the preset parallel voltage variables. This represents the preset original parallel control factor.

[0095] Understandably, the current vertical current variable refers to the dependent variable used to represent the current vertical current in the original observation model; the current parallel current variable refers to the dependent variable used to represent the current parallel current in the original observation model; the historical vertical current variable refers to the independent variable used to represent the historical vertical current in the original observation model; the historical parallel current variable refers to the independent variable used to represent the historical parallel current in the original observation model; the inductance variable refers to the independent variable used to represent the inductance in the original observation model; the resistance variable refers to the independent variable used to represent the resistance in the original observation model; the vertical voltage variable refers to the independent variable of voltage in the vertical direction; the parallel voltage variable refers to the independent variable of voltage in the parallel direction; the original vertical control factor refers to the parameter used to compensate for errors in the observation parameters in the vertical direction; and the original parallel control factor refers to the parameter used to compensate for errors in the observation parameters in the parallel direction.

[0096] Furthermore, since the state observer is used to estimate the state parameters of the brushless motor under test, there is a certain error between the observed values ​​and the actual parameters of the brushless motor under test. For example, there is a numerical error between the observed vertical current of the brushless motor under test estimated by the state observer and the actual original vertical current. In order to reduce this error, control factors need to be introduced, including vertical control factors and parallel control factors, to compensate for this error. When the original observation model is being built for the first time, the original vertical control factors and original parallel control factors can be set manually. When the original observation model is not being built for the first time, the original vertical control factors and original parallel control factors are the vertical control factors and parallel control factors in the observation model obtained in the previous sampling period.

[0097] S4. Using the original observation model, calculate the state parameters of the brushless motor under test to obtain the observed operating current set, wherein the number of observed operating currents in the observed operating current set is the same as the number of original operating currents in the original operating current set.

[0098] Understandably, the observed operating current set refers to the collection of observed operating currents, and the observed operating current refers to the operating current of the brushless motor under test obtained after calculation by the original observation model. This observed operating current corresponds to the original operating current collected by the current sensor mentioned above.

[0099] In detail, the process of using the original observation model to calculate the state parameters of the brushless motor under test and obtaining the observed operating current set includes:

[0100] In the step of detecting the current of the brushless motor under test based on the current sensor, the synchronous parameters of the brushless motor under test are detected by the voltage sensor, resistance sensor and inductance sensor to obtain a synchronous motor parameter set. The synchronous motor parameter set includes multiple synchronous motor parameters, including: synchronous motor resistance, synchronous motor inductance, synchronous vertical voltage and synchronous parallel voltage.

[0101] If the step of performing synchronization parameter detection on the brushless motor under test is the first time performing synchronization parameter detection, then the preset zero values ​​are recorded as historical vertical current and historical parallel current respectively.

[0102] If the step of performing synchronization parameter detection on the brushless motor under test is not the first time performing synchronization parameter detection, then query the historical vertical current and historical parallel current.

[0103] Synchronous motor parameters are extracted sequentially from the synchronous motor parameter set. The synchronous motor parameters, historical vertical current, and historical parallel current are substituted into the original observation model to obtain the observed operating current, wherein the observed operating current includes the observed vertical current and the observed parallel current.

[0104] The observed operating currents are summarized to obtain the observed operating current set.

[0105] It is clear that the synchronous parameter detection refers to simultaneously using a current detector to detect the current of the brushless motor under test, and using a voltage detector, a resistance detector, and an inductance detector to detect the voltage, resistance, and inductance of the brushless motor under test, respectively. The synchronous motor parameter set refers to the set of synchronous motor parameters. The synchronous motor resistance and synchronous motor inductance refer to the resistance and inductance of the brushless motor under test detected by the voltage detector and the inductance detector, respectively. The synchronous vertical voltage and synchronous parallel voltage refer to the voltage of the brushless motor under test perpendicular to the rotor magnetic field direction and the voltage parallel to the rotor magnetic field direction detected by the voltage detector, respectively.

[0106] It should be explained that the zero value refers to a constant of zero, the historical vertical current refers to the observed vertical current obtained from the original observation model when the synchronous motor parameters were last collected, with the current time of synchronous motor parameter acquisition as a reference. When the synchronous parameter detection is performed for the first time, the historical vertical current is 0. Similarly, the historical parallel current is the observed parallel current obtained from the previous original observation model. The observed vertical current and observed parallel current refer to the outputs corresponding to the current vertical current variable and the current parallel current variable in the original observation model, respectively. The observed operating current set refers to the set of observed operating currents.

[0107] S5. Perform observation error analysis based on the observed operating current set and the original operating current set to obtain the observation error value, and determine whether the observation error value is greater than the preset minimum error value.

[0108] It should be explained that the observation error value represents the numerical difference between the observed operating current set and the original operating current set. The greater the difference between the observed operating current set and the original operating current set, the greater the observation error value; conversely, the smaller the difference between the observed operating current set and the original operating current set, the smaller the observation error value. The minimum error value refers to the minimum value of the observation error set that is set manually.

[0109] In detail, the step of performing observation error analysis based on the observed operating current set and the original operating current set to obtain the observation error value includes:

[0110] Based on the observed operating current set and the original operating current set, effective current data analysis is performed to obtain the effective current error factor set and the effective fluctuation weight set.

[0111] Based on the effective current error factor set and the effective fluctuation weight set, the observation error value is calculated using the following formula:

[0112]

[0113] in, This represents the observation error value. This indicates the number of effective current error factors in the effective current error factor set or the number of effective fluctuation weights in the effective fluctuation weight set. Represents the first in the effective fluctuation weight set One effective fluctuation weight, Represents the first in the effective current error factor set One effective current error factor.

[0114] It is clear that the effective current error factor set refers to the set of effective current error factors, wherein the effective current error factor refers to the numerical value of the data difference between the observed operating current and the corresponding original operating current, and the effective fluctuation weight set refers to the set of effective fluctuation weights, wherein the effective fluctuation weight refers to the calculation weight of the effective current error factor when calculating the observed error value in the subsequent calculation.

[0115] In detail, the step of performing effective current data analysis based on the observed operating current set and the original operating current set to obtain an effective current error factor set and an effective fluctuation weight set includes:

[0116] Record the completion time of the step of detecting the current of the brushless motor under test based on the current sensor;

[0117] The observed operating current and the original operating current corresponding to the observed operating current are extracted sequentially from the observed operating current set and the original operating current set, and the current acquisition time of the observed operating current and the original operating current is obtained. The time fluctuation weight between the detection completion time and the current acquisition time is calculated.

[0118] Calculate the error factor per unit current;

[0119] If it is confirmed that the unit current error factor is not greater than the preset controllable error factor, then the unit current error factor and the time fluctuation weight are respectively recorded as the effective current error factor and the effective fluctuation weight.

[0120] The effective current error factor and the effective fluctuation weight are summarized respectively to obtain the effective current error factor set and the effective fluctuation weight set.

[0121] Understandably, the "detection completion time" refers to the moment when the current detection step of the brushless motor under test based on the current sensor is completed; the "current acquisition time" refers to the moment when the observed operating current and the original operating current are acquired; the "duration fluctuation weight" refers to the absolute difference between the detection completion time and the current acquisition time; the "unit current error factor" refers to the numerical value of the data difference between the observed operating current and the original operating current; and the "controllable error factor" refers to a human-set error factor constant. When the unit error factor is greater than the controllable error factor, it indicates that the unit current error factor is too large, resulting in abnormal data, and therefore the unit current error factor cannot be substituted into the calculation of subsequent observation error values.

[0122] It should be explained that the purpose of introducing the duration fluctuation weight in the calculation of the observation error value is: since the current data collected near the end of the test is more consistent with the current change trend of the brushless motor under test, the unit current error factor near the end of the test should be given a higher calculation weight.

[0123] Specifically, the calculation of the unit current error factor includes:

[0124] Based on the observed operating current and the original operating current, the unit current error factor is calculated, wherein the unit current error factor is expressed as:

[0125]

[0126] in, Indicates the error factor per unit current. This represents the initial vertical current in the initial operating current. This represents the observed vertical current in the observed operating current. This represents the original parallel current in the original operating current. This represents the observed parallel current in the observed operating current.

[0127] S6. If the observation error value is greater than the minimum error value, the original observation model is adjusted to obtain an adjusted observation model.

[0128] Understandably, the adjusted observation model refers to the original observation model after adjustment.

[0129] In detail, adjusting the original observation model to obtain an adjusted observation model includes:

[0130] An adjustment amplitude factor is set based on the sampling period, wherein the adjustment amplitude factor is expressed as:

[0131]

[0132] Among them, the Indicates the adjustment amplitude factor. This represents a preset selection constant;

[0133] Based on the adjustment amplitude factor, the vertical control factor and the horizontal control factor are calculated using the following formula:

[0134]

[0135]

[0136] in, This indicates adjustment of the vertical control factor. Indicates the adjustment of parallel control factors;

[0137] The original vertical control factor and the original parallel control factor in the original observation model are replaced by the adjusted vertical control factor and the adjusted parallel control factor, respectively, to obtain the adjusted observation model.

[0138] It should be explained that the adjustment amplitude factor refers to a manually set value representing the adjustment amplitude when adjusting the original observation model. The larger the adjustment amplitude required by the original observation model, the smaller the adjustment amplitude factor; conversely, the smaller the adjustment amplitude required by the original observation model, the larger the adjustment amplitude factor. The value of the adjustment amplitude factor is related to the sampling period. Usually, the value of the adjustment amplitude factor is in an integer proportional relationship with the sampling period. That is, the adjustment amplitude factor can be determined by selecting a constant. The selection constant is a manually set constant. When the motor operator wants the brushless motor under test to quickly complete the detection of rotor position and rotor speed, the selection constant can be set to 1. Compared with other selection constants, such as 2 to 9, the adjustment amplitude is larger when adjusting the original observation model under this selection constant, and thus the adjustment speed is faster. If the motor operator wants to maintain higher accuracy when detecting rotor position and rotor speed, the selection constant can be set to 10. Compared with other selection constants, such as 1 to 9, the adjustment amplitude is smaller when adjusting the original observation model under this selection constant, and the adjustment accuracy is higher.

[0139] S7. Using the adjusted observation model as the original observation model, return to the step of using the original observation model to calculate the state parameters of the brushless motor under test until the observation error value is not greater than the minimum error value, and record the original observation model at this time as the target observation model.

[0140] Understandably, the target observation model refers to the original observation model when the observation error value is not less than the minimum error value. When the observation error value is greater than the minimum error value, it indicates that the error between the observed parameters obtained from the original observation model and the actual parameters is not within a controllable range. In this case, the original observation model needs to be adjusted to obtain an adjusted observation model. Then, the observation error value needs to be recalculated on the adjusted observation model. That is, the adjusted observation model needs to be used as the original observation model, and this original observation model is substituted into the above steps of using the original observation model to calculate the state parameters of the brushless motor under test. When the observation error value is not less than the minimum error value, it indicates that the observed parameters obtained from the original observation model can match the actual parameters well. This original observation model can be used as the observation model for the final calculation of the rotor position angle and rotor speed.

[0141] S8. Based on the target observation model, calculate the observed rotor position angle and observed rotor speed, and complete the sensorless brushless motor control based on the observed rotor position angle and observed rotor speed.

[0142] It is clear that the observed rotor position angle refers to the rotor position angle of the brushless motor under test obtained through the target observation model, where the rotor position angle refers to the angle between the rotor magnetic poles and the stator windings. The observed rotor speed refers to the rotor speed of the brushless motor under test obtained through the target observation model, where the rotor speed refers to the angular velocity of the rotor during rotation.

[0143] In detail, the calculation of the observed rotor position angle and observed rotor speed based on the target observation model includes:

[0144] Identify the target vertical control factor and the target parallel control factor in the target observation model;

[0145] The vertical back electromotive force in the target vertical control factor and the parallel back electromotive force in the target parallel control factor are extracted using a preset low-pass filter.

[0146] Based on the vertical back electromotive force and the parallel back electromotive force, the observed rotor position angle and the observed rotor speed are calculated, wherein the observed rotor position angle and the observed rotor speed are respectively expressed as:

[0147]

[0148]

[0149] in, Indicates the observed rotor position angle. Represents the arctangent function in the four quadrants. Represents the vertical back electromotive force. This represents the parallel back electromotive force. Indicates the observed rotor speed. This represents the preset back electromotive force constant.

[0150] Understandably, the target vertical control factor refers to the original vertical control factor in the target observation model, and the target parallel control factor refers to the original parallel control factor in the target observation model. The low-pass filter refers to a signal processing tool used to extract the DC component from a signal. The vertical back EMF refers to the back EMF perpendicular to the rotor magnetic field direction, and the parallel back EMF refers to the back EMF parallel to the rotor magnetic field direction. The back EMF is an induced voltage generated during motor operation. When the motor rotor rotates, its magnetic field induces a voltage in the stator windings; this voltage is the back EMF. The back EMF constant refers to a proportionality constant, representing the magnitude of the back EMF generated per unit speed of the motor, which can be found in the specifications of the brushless motor under test.

[0151] To address the problems described in the background section, this invention first starts the brushless motor under test (BMT). This BMT does not contain position or speed sensors, thus reducing the cost, complexity, and failure risk of controlling the BMT. Next, current is detected in the BMT using a current sensor to obtain the original operating current set. This step allows real-time acquisition of the motor's current information, including vertical and parallel currents, providing foundational data for subsequent state estimation. Then, parameters such as resistance and inductance in the BMT are detected, and an initial observation model for the state observer is constructed based on these parameters. This model describes the dynamic characteristics of the motor during operation, providing a specific calculation method for subsequent estimation of rotor position and rotor speed. Furthermore, using the initial observation model, state parameters of the BMT are calculated. The system observes the operating current set and calculates the observation error between the original and observed operating current sets. Based on this error, it dynamically adjusts the original observation model. This adjustment method progressively modifies the original observation model of the state observer, ensuring it remains in an optimal state and achieving high-precision tracking of the motor's operating state. This approach not only improves the accuracy of rotor position and speed detection but also enhances the stability of motor control. Through this dynamic adjustment mechanism, the final target observation model can accurately estimate the rotor position angle and speed, especially during low-speed operation and startup, where traditional methods often struggle to accurately obtain rotor position information. This method effectively solves this problem by continuously adjusting the original observation model, achieving stable control across the entire speed range. Therefore, this invention improves the accuracy of rotor parameter detection and the stability of motor control in brushless motor control.

[0152] like Figure 2 The diagram shown is a functional block diagram of a sensorless brushless motor control system based on a state observer provided in an embodiment of the present invention.

[0153] The sensorless brushless motor control system 100 based on a state observer described in this invention can be installed in an electronic device. Depending on the functions implemented, the sensorless brushless motor control system 100 based on a state observer may include a raw current acquisition module 101, a motor current observation module 102, an observation model adjustment module 103, and a rotor parameter calculation module 104. The module described in this invention can also be called a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, and are stored in the memory of the electronic device.

[0154] The raw current acquisition module 101 is used to receive motor control commands and start the brushless motor under test based on the motor control commands. The brushless motor under test has a built-in current sensor, voltage sensor, resistance sensor, inductance sensor and state observer. The current sensor detects the current of the brushless motor under test to obtain a raw operating current set. The raw operating current set includes multiple raw operating currents, and each raw operating current includes a raw vertical current and a raw parallel current.

[0155] The motor current observation module 102 is used to construct the original observation model of the state observer. Using the original observation model, the state parameters of the brushless motor under test are calculated to obtain the observed operating current set. The number of observed operating currents in the observed operating current set is the same as the number of original operating currents in the original operating current set.

[0156] The observation model adjustment module 103 is used to perform observation error analysis based on the observed operating current set and the original operating current set, obtain the observation error value, and determine whether the observation error value is greater than a preset minimum error value. If the observation error value is greater than the minimum error value, the original observation model is adjusted to obtain an adjusted observation model.

[0157] The rotor parameter calculation module 104 is used to take the adjustment observation model as the original observation model, return to the step of using the original observation model to calculate the state parameters of the brushless motor under test, until the observation error value is not greater than the minimum error value, and record the original observation model at this time as the target observation model, and calculate the observed rotor position angle and observed rotor speed according to the target observation model.

[0158] In detail, the modules in the sensorless brushless motor control system 100 based on a state observer described in this embodiment of the invention employ the same methods as described above. Figure 1 The method described herein uses the same technical means as the sensorless brushless motor control method based on state observer, and can produce the same technical effect, so it will not be repeated here.

[0159] like Figure 3 The diagram shown is a structural schematic of an electronic device that implements a sensorless brushless motor control method based on a state observer, according to an embodiment of the present invention.

[0160] The electronic device 1 may include a processor 10, a memory 11 and a bus 12, and may also include a computer program stored in the memory 11 and executable on the processor 10, such as a sensorless brushless motor control method program based on a state observer.

[0161] The memory 11 includes at least one type of readable storage medium, such as flash memory, portable hard drive, multimedia card, card-type memory (e.g., SD or DX memory), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 11 can be an internal storage unit of the electronic device 1, such as the portable hard drive of the electronic device 1. In other embodiments, the memory 11 can be an external storage device of the electronic device 1, such as a plug-in portable hard drive, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the electronic device 1. Furthermore, the memory 11 includes both internal storage units and external storage devices of the electronic device 1. The memory 11 can be used not only to store application software and various types of data installed on the electronic device 1, such as the code of a sensorless brushless motor control method program based on a state observer, but also to temporarily store data that has been output or will be output.

[0162] In some embodiments, the processor 10 may be composed of integrated circuits, such as a single packaged integrated circuit or multiple integrated circuits with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 10 is the control unit of the electronic device, connecting various components of the entire electronic device through various interfaces and lines. It executes programs or modules stored in the memory 11 (e.g., a sensorless brushless motor control method program based on a state observer) and calls data stored in the memory 11 to perform various functions of the electronic device 1 and process data.

[0163] The bus 12 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus 12 can be divided into an address bus, a data bus, a control bus, etc. The bus 12 is configured to realize the connection and communication between the memory 11 and at least one processor 10, etc.

[0164] Figure 3 Only electronic devices with components are shown; it will be understood by those skilled in the art that... Figure 3The structure shown does not constitute a limitation on the electronic device 1, and may include fewer or more components than shown, or combine certain components, or have different component arrangements.

[0165] For example, although not shown, the electronic device 1 may also include a power supply (such as a battery) to power the various components. Preferably, the power supply can be logically connected to the at least one processor 10 through a power management system, thereby enabling functions such as charging management, discharging management, and power consumption management through the power management system. The power supply may also include one or more DC or AC power supplies, recharging systems, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components. The electronic device 1 may also include various sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be described in detail here.

[0166] Furthermore, the electronic device 1 may also include a network interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a Wi-Fi interface, a Bluetooth interface, etc.), which is typically used to establish communication connections between the electronic device 1 and other electronic devices.

[0167] Optionally, the electronic device 1 may further include a user interface, which may be a display, an input unit (such as a keyboard), and optionally, a standard wired interface or a wireless interface. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen, etc. The display may also be appropriately referred to as a screen or display unit, used to display information processed in the electronic device 1 and to display a visual user interface.

[0168] The sensorless brushless motor control method program based on a state observer, stored in the memory 11 of the electronic device 1, is a combination of multiple instructions. When run in the processor 10, it can achieve the following:

[0169] Receive motor control commands and start the brushless motor under test based on the motor control commands, wherein the brushless motor under test has built-in current detector, voltage detector, resistance detector, inductance detector and state observer;

[0170] The brushless motor under test is subjected to current detection using a current sensor to obtain an original operating current set. The original operating current set includes multiple original operating currents, and each original operating current includes an original vertical current and an original parallel current.

[0171] Construct the original observation model of the state observer;

[0172] Using the original observation model, the state parameters of the brushless motor under test are calculated to obtain the observed operating current set, wherein the number of observed operating currents in the observed operating current set is the same as the number of original operating currents in the original operating current set.

[0173] Based on the observed operating current set and the original operating current set, an observation error analysis is performed to obtain the observation error value, and it is determined whether the observation error value is greater than the preset minimum error value.

[0174] If the observation error value is greater than the minimum error value, the original observation model is adjusted to obtain an adjusted observation model.

[0175] The adjusted observation model is used as the original observation model. The process of calculating the state parameters of the brushless motor under test using the original observation model is repeated until the observation error value is not greater than the minimum error value. The original observation model at this time is then recorded as the target observation model.

[0176] Based on the target observation model, the observed rotor position angle and observed rotor speed are calculated, and sensorless brushless motor control based on the observed rotor position angle and observed rotor speed is completed.

[0177] Specifically, the processor 10's implementation method for the above instructions can be found in [reference needed]. Figures 1 to 3 The descriptions of the relevant steps in the corresponding embodiments are not repeated here.

[0178] Furthermore, if the modules / units integrated in the electronic device 1 are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. The computer-readable storage medium can be volatile or non-volatile. For example, the computer-readable medium may include: any entity or system capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, or a read-only memory (ROM).

[0179] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor of an electronic device, can perform the following:

[0180] Receive motor control commands and start the brushless motor under test based on the motor control commands, wherein the brushless motor under test has built-in current detector, voltage detector, resistance detector, inductance detector and state observer;

[0181] The brushless motor under test is subjected to current detection using a current sensor to obtain an original operating current set. The original operating current set includes multiple original operating currents, and each original operating current includes an original vertical current and an original parallel current.

[0182] Construct the original observation model of the state observer;

[0183] Using the original observation model, the state parameters of the brushless motor under test are calculated to obtain the observed operating current set, wherein the number of observed operating currents in the observed operating current set is the same as the number of original operating currents in the original operating current set.

[0184] Based on the observed operating current set and the original operating current set, an observation error analysis is performed to obtain the observation error value, and it is determined whether the observation error value is greater than the preset minimum error value.

[0185] If the observation error value is greater than the minimum error value, the original observation model is adjusted to obtain an adjusted observation model.

[0186] The adjusted observation model is used as the original observation model. The process of calculating the state parameters of the brushless motor under test using the original observation model is repeated until the observation error value is not greater than the minimum error value. The original observation model at this time is then recorded as the target observation model.

[0187] Based on the target observation model, the observed rotor position angle and observed rotor speed are calculated, and sensorless brushless motor control based on the observed rotor position angle and observed rotor speed is completed.

[0188] In the embodiments provided by this invention, it should be understood that the disclosed devices, systems, and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative, and actual implementations may have other classification methods.

[0189] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0190] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0191] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0192] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A sensorless brushless motor control method based on a state observer, characterized in that, The method includes: Receive motor control commands and start the brushless motor under test based on the motor control commands, wherein the brushless motor under test has built-in current detector, voltage detector, resistance detector, inductance detector and state observer; The brushless motor under test is subjected to current detection using a current sensor to obtain an original operating current set. The original operating current set includes multiple original operating currents, and each original operating current includes an original vertical current and an original parallel current. Constructing the original observation model of the state observer includes: Set the current current variable and the historical current variable, wherein the current current variable includes: the current vertical current variable and the current parallel current variable, and the historical current variable includes: the historical vertical current variable and the historical parallel current variable; Based on the sampling period, current current variable, and historical current variable, an original observation model is constructed, wherein the original observation model is expressed as: ； in, Represents the original observation model. Indicates the current vertical current variable. Represents historical vertical current variables. Indicates the sampling period. This represents the preset inductance variable. This represents the preset vertical voltage variable. This indicates the preset resistance variable. This represents the preset initial vertical control factor. Indicates the current parallel current variable. Represents historical parallel current variables. The table shows the preset parallel voltage variables. This represents the preset initial parallel control factor; Using the original observation model, the state parameters of the brushless motor under test are calculated to obtain the observed operating current set, wherein the number of observed operating currents in the observed operating current set is the same as the number of original operating currents in the original operating current set. Based on the observed operating current set and the original operating current set, an observation error analysis is performed to obtain the observation error value, and it is determined whether the observation error value is greater than the preset minimum error value. If the observation error value is greater than the minimum error value, the original observation model is adjusted to obtain an adjusted observation model, including: An adjustment amplitude factor is set based on the sampling period, wherein the adjustment amplitude factor is expressed as: ； Among them, the Indicates the adjustment amplitude factor. This represents a preset selection constant; Based on the adjustment amplitude factor, the vertical control factor and the horizontal control factor are calculated using the following formula: ； in, This indicates adjustment of the vertical control factor. Indicates the adjustment of parallel control factors; By replacing the original vertical control factor and the original parallel control factor in the original observation model with the adjusted vertical control factor and the adjusted parallel control factor respectively, an adjusted observation model is obtained. The adjusted observation model is used as the original observation model. The process of calculating the state parameters of the brushless motor under test using the original observation model is repeated until the observation error value is not greater than the minimum error value. The original observation model at this time is then recorded as the target observation model. Based on the target observation model, the observed rotor position angle and observed rotor speed are calculated, and sensorless brushless motor control based on the observed rotor position angle and observed rotor speed is completed.

2. The sensorless brushless motor control method based on a state observer as described in claim 1, characterized in that, The current detection of the brushless motor under test based on the current sensor yields the original operating current set, including: Under a preset current detection period, the current signal is monitored using the current detector to obtain a continuous operating current, wherein the continuous operating current is a current signal that changes continuously under the current detection period. The sampling period of the state observer is obtained, and based on the sampling period, discrete current is collected in the continuous operating current to obtain the original operating current set.

3. The sensorless brushless motor control method based on a state observer as described in claim 2, characterized in that, The process involves using the original observation model to calculate the state parameters of the brushless motor under test, resulting in an observed operating current set, including: In the step of detecting the current of the brushless motor under test based on the current sensor, the synchronous parameters of the brushless motor under test are detected by the voltage sensor, resistance sensor and inductance sensor to obtain a synchronous motor parameter set. The synchronous motor parameter set includes multiple synchronous motor parameters, including: synchronous motor resistance, synchronous motor inductance, synchronous vertical voltage and synchronous parallel voltage. If the step of performing synchronization parameter detection on the brushless motor under test is the first time performing synchronization parameter detection, then the preset zero values ​​are recorded as historical vertical current and historical parallel current respectively. If the step of performing synchronization parameter detection on the brushless motor under test is not the first time performing synchronization parameter detection, then query the historical vertical current and historical parallel current. Synchronous motor parameters are extracted sequentially from the synchronous motor parameter set. The synchronous motor parameters, historical vertical current, and historical parallel current are substituted into the original observation model to obtain the observed operating current, wherein the observed operating current includes the observed vertical current and the observed parallel current. The observed operating currents are summarized to obtain the observed operating current set.

4. The sensorless brushless motor control method based on a state observer as described in claim 3, characterized in that, The step of performing observation error analysis based on the observed operating current set and the original operating current set to obtain the observation error value includes: Based on the observed operating current set and the original operating current set, effective current data analysis is performed to obtain the effective current error factor set and the effective fluctuation weight set. Based on the effective current error factor set and the effective fluctuation weight set, the observation error value is calculated using the following formula: ； in, This represents the observation error value. This indicates the number of effective current error factors in the effective current error factor set or the number of effective fluctuation weights in the effective fluctuation weight set. Represents the first in the effective fluctuation weight set One effective fluctuation weight, Represents the first in the effective current error factor set One effective current error factor.

5. The sensorless brushless motor control method based on a state observer as described in claim 4, characterized in that, The step involves analyzing the effective current data based on the observed operating current set and the original operating current set to obtain an effective current error factor set and an effective fluctuation weight set, including: Record the completion time of the step of detecting the current of the brushless motor under test based on the current sensor; The observed operating current and the original operating current corresponding to the observed operating current are extracted sequentially from the observed operating current set and the original operating current set, and the current acquisition time of the observed operating current and the original operating current is obtained. The time fluctuation weight between the detection completion time and the current acquisition time is calculated. Calculate the error factor per unit current; If it is confirmed that the unit current error factor is not greater than the preset controllable error factor, then the unit current error factor and the time fluctuation weight are respectively recorded as the effective current error factor and the effective fluctuation weight. The effective current error factor and the effective fluctuation weight are summarized respectively to obtain the effective current error factor set and the effective fluctuation weight set.

6. The sensorless brushless motor control method based on a state observer as described in claim 5, characterized in that, The calculation of the unit current error factor includes: Based on the observed operating current and the original operating current, the unit current error factor is calculated, wherein the unit current error factor is expressed as: ； in, Indicates the error factor per unit current. This represents the initial vertical current in the initial operating current. This represents the observed vertical current in the observed operating current. This represents the original parallel current in the original operating current. This represents the observed parallel current in the observed operating current.

7. The sensorless brushless motor control method based on a state observer as described in claim 6, characterized in that, The step of calculating the observed rotor position angle and observed rotor speed based on the target observation model includes: Identify the target vertical control factor and the target parallel control factor in the target observation model; The vertical back electromotive force in the target vertical control factor and the parallel back electromotive force in the target parallel control factor are extracted using a preset low-pass filter. Based on the vertical back electromotive force and the parallel back electromotive force, the observed rotor position angle and the observed rotor speed are calculated, wherein the observed rotor position angle and the observed rotor speed are respectively expressed as: ； ； in, Indicates the observed rotor position angle. Represents the arctangent function in the four quadrants. Represents the vertical back electromotive force. This represents the parallel back electromotive force. Indicates the observed rotor speed. This represents the preset back electromotive force constant.

8. A sensorless brushless motor control system based on a state observer, characterized in that, The system includes: The raw current acquisition module is used to receive motor control commands and start the brushless motor under test based on the motor control commands. The brushless motor under test has a built-in current sensor, voltage sensor, resistance sensor, inductance sensor and state observer. The current sensor detects the current of the brushless motor under test to obtain a raw operating current set. The raw operating current set includes multiple raw operating currents, and each raw operating current includes a raw vertical current and a raw parallel current. The motor current observation module, used to construct the original observation model of the state observer, includes: Set the current current variable and the historical current variable, wherein the current current variable includes: the current vertical current variable and the current parallel current variable, and the historical current variable includes: the historical vertical current variable and the historical parallel current variable; Based on the sampling period, current current variable, and historical current variable, an original observation model is constructed, wherein the original observation model is expressed as: ； in, Represents the original observation model. Indicates the current vertical current variable. Represents historical vertical current variables. Indicates the sampling period. This represents the preset inductance variable. This represents the preset vertical voltage variable. This indicates the preset resistance variable. This represents the preset initial vertical control factor. Indicates the current parallel current variable. Represents historical parallel current variables. The table shows the preset parallel voltage variables. The preset original parallel control factor is used to calculate the state parameters of the brushless motor under test using the original observation model, and the observed operating current set is obtained. The number of observed operating currents in the observed operating current set is the same as the number of original operating currents in the original operating current set. The observation model adjustment module is used to perform observation error analysis based on the observed operating current set and the original operating current set, obtain the observation error value, and determine whether the observation error value is greater than a preset minimum error value. If the observation error value is greater than the minimum error value, the original observation model is adjusted to obtain an adjusted observation model, including: An adjustment amplitude factor is set based on the sampling period, wherein the adjustment amplitude factor is expressed as: ； Among them, the Indicates the adjustment amplitude factor. This represents a preset selection constant; Based on the adjustment amplitude factor, the vertical control factor and the horizontal control factor are calculated using the following formula: ； in, This indicates adjustment of the vertical control factor. Indicates the adjustment of parallel control factors; By replacing the original vertical control factor and the original parallel control factor in the original observation model with the adjusted vertical control factor and the adjusted parallel control factor respectively, an adjusted observation model is obtained. The rotor parameter calculation module is used to take the adjustment observation model as the original observation model, return to the step of using the original observation model to calculate the state parameters of the brushless motor under test, until the observation error value is not greater than the minimum error value, and record the original observation model at this time as the target observation model. Based on the target observation model, the observed rotor position angle and observed rotor speed are calculated.

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