A method and device for automatic calibration of zero-position deviation of brushless motor angle sensor

Abstract

This invention discloses an automatic calibration method and device for zero-position deviation of a brushless motor angle sensor, belonging to the field of vehicle technology. The method includes: after receiving a calibration command from a host computer, allowing the motor to enter an open-loop control mode; after the motor speed reaches a stable state in the open-loop control mode, acquiring the raw ADC value output by the angle sensor; calculating the offset and amplitude gain of the angle sensor based on the signal processing mode of the angle sensor and the raw ADC value output by the angle sensor; and determining the zero-position deviation based on the offset and amplitude gain of the angle sensor. This invention utilizes an open-loop voltage vector to drive the motor rotation to obtain the complete waveform characteristics of the sensor, solving the problem of calibration without free rotation in a closed-loop state. Simultaneously, differential processing of the dual-ended signals is implemented at the software level, extracting the common-mode rejection characteristics of the differential signals and improving calibration accuracy.

Description

Technical Field

[0001] This invention belongs to the field of vehicle technology, specifically relating to an automatic calibration method and device for zero-position deviation of a brushless motor angle sensor. Background Technology

[0002] In vector control of brushless DC motors and permanent magnet synchronous motors, accurate rotor position feedback is a prerequisite for achieving high-efficiency, high-dynamic-response control. Resolver sensors (i.e., angle sensors) are widely used in automotive electronics, industrial servo systems, and other fields due to their high robustness. However, mechanical installation errors are unavoidable during the installation of angle sensors, resulting in a phase deviation between the electrical zero position of the angle sensor and the zero position of the motor (i.e., zero-position deviation). Without calibration, this can lead to motor start-up jitter, increased torque pulsation, and reduced efficiency. Summary of the Invention

[0003] One objective of this invention is to provide an automatic calibration method and device for zero-position deviation of a brushless motor angle sensor, which can solve the aforementioned technical problems in the prior art.

[0004] According to a first aspect of the present invention, an automatic calibration method for zero-position deviation of a brushless motor angle sensor is provided, comprising:

[0005] After receiving the calibration command from the host computer, the motor is put into open-loop control mode;

[0006] After the motor speed reaches a stable state in the open-loop control mode, the original ADC value output by the angle sensor is collected.

[0007] The offset and amplitude gain of the angle sensor are calculated based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor.

[0008] The zero-position deviation is determined based on the offset and amplitude gain of the angle sensor.

[0009] Optionally, the raw ADC value output by the angle sensor includes the positive terminal output of the sine signal, the positive terminal output of the cosine signal, the negative terminal output of the sine signal, and the negative terminal output of the cosine signal.

[0010] The step of calculating the offset and amplitude gain of the angle sensor based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor includes:

[0011] The original sine signal and the original cosine signal are determined based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor.

[0012] The offset and amplitude gain of the angle sensor are calculated based on the original sine and cosine signals.

[0013] Optionally, determining the original sine and cosine signals based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor includes:

[0014] When the signal processing mode of the angle sensor is single-ended, the positive output of the sine signal is determined as the original sine signal, and the positive output of the cosine signal is determined as the original cosine signal.

[0015] Optionally, determining the original sine and cosine signals based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor includes:

[0016] When the signal processing mode of the angle sensor is in dual-end mode, the original sine signal is determined based on the positive terminal output and the negative terminal output of the sine signal, and the original cosine signal is determined based on the positive terminal output and the negative terminal output of the cosine signal.

[0017] Optionally, determining the original sine signal based on the positive output and the negative output of the sine signal includes:

[0018] The difference of the sine signal is calculated based on the positive output and the negative output of the sine signal.

[0019] The original sine signal is determined based on the difference of the sine signal.

[0020] Optionally, determining the original cosine signal based on the positive output and the negative output of the cosine signal includes:

[0021] The cosine signal difference is calculated based on the positive output and the negative output of the cosine signal.

[0022] The original cosine signal is determined based on the difference of the cosine signal.

[0023] Optionally, the offset of the angle sensor includes a sine offset and a cosine offset, and the amplitude gain of the angle sensor includes the amplitude gain of the sine signal and the amplitude gain of the cosine signal.

[0024] The calculation of the offset and amplitude gain of the angle sensor based on the original sine signal and the original cosine signal includes:

[0025] Determine the maximum value and the minimum value of the original sinusoidal signal;

[0026] The sine offset and the amplitude gain of the sine signal are determined based on the maximum value and the minimum value of the original sine signal.

[0027] Determine the maximum value and the minimum value of the original cosine signal;

[0028] The cosine offset and the amplitude gain of the cosine signal are determined based on the maximum value and the minimum value of the original cosine signal.

[0029] Optionally, determining the zero-position deviation based on the offset and amplitude gain of the angle sensor includes:

[0030] The motor is controlled to operate according to multiple set open-loop target angles;

[0031] When the motor reaches each of the target angles, the angle signal output by the angle sensor corresponding to the target angle is acquired;

[0032] The electrical angle corresponding to each target angle is obtained by calculating the angle signal output by the angle sensor corresponding to the target angle, as well as the offset and amplitude gain of the angle sensor.

[0033] The zero-position deviation is determined based on each of the target angles and the corresponding electrical angles.

[0034] Optionally, determining the zero-position deviation based on each target angle and the corresponding electrical angle includes:

[0035] Calculate the angular deviation between each target angle and the corresponding electrical angle;

[0036] The average value of all angular deviations is determined as the zero deviation.

[0037] According to a second aspect of the present invention, an electronic device is provided, including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of an automatic calibration method for zero-position deviation of a brushless motor angle sensor as described in the first aspect of the present invention.

[0038] The beneficial effects of this invention are as follows: This invention utilizes an open-loop voltage vector to drive the motor rotation to obtain the complete waveform characteristics of the sensor, solving the problem of calibration without free rotation in a closed-loop state. Simultaneously, differential processing of the dual-ended signals is implemented at the software level, extracting the common-mode rejection characteristics of the differential signals and improving calibration accuracy. Furthermore, by forcibly pulling the motor to 0 electrical angle and a small angle nearby, and sampling multiple times and averaging, the physical deviation between the sensor zero position and the motor zero position is accurately captured. Attached Figure Description

[0039] Figure 1 This is a flowchart of an automatic calibration method for zero-position deviation of a brushless motor angle sensor according to an embodiment of the present invention.

[0040] Figure 2 This is a schematic diagram of the data collected by the angle sensor in an embodiment of the present invention. Detailed Implementation

[0041] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0042] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0043] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0045] In the specification of this invention, the terms "first" and "second" may explicitly or implicitly include one or more of the same feature. In the description of this invention, unless otherwise stated, "multiple" means two or more. Furthermore, in the specification, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0046] In vector control of brushless DC motors and permanent magnet synchronous motors, accurate rotor position feedback is a prerequisite for achieving high-efficiency, high-dynamic-response control. Resolver sensors (i.e., angle sensors) are widely used in automotive electronics, industrial servo systems, and other fields due to their high robustness. However, mechanical installation errors are unavoidable during the installation of angle sensors, resulting in a phase deviation between the electrical zero position of the angle sensor and the zero position of the motor (i.e., zero-position deviation). Without calibration, this can lead to motor start-up jitter, increased torque pulsation, and reduced efficiency.

[0047] Currently, common calibration methods mainly include physical equipment calibration and general algorithm calibration.

[0048] Physical equipment calibration method: Using a high-precision turntable or oscilloscope, the difference between the zero-crossing point of the back EMF and the sensor signal is manually measured on the production line. This method's accuracy depends on external equipment, increasing manufacturing costs and time, making it expensive, and it cannot eliminate secondary errors after the motor is assembled at the user end.

[0049] General algorithm calibration method: Online identification is performed using the back EMF observer of the motor or the high-frequency injection method. This type of method usually requires complex observer algorithms, has high computing power requirements for MCU (Microcontroller Unit), and has poor identification accuracy at low speeds or when stationary.

[0050] The existing technology has the following problems:

[0051] (1) High cost and low efficiency: Reliance on expensive external testing equipment increases production costs and labor time;

[0052] (2) Limited applicability: Existing online identification algorithms often require the motor to run under specific loads or speeds, making it difficult to achieve high-precision calibration under no-load or low-speed stationary conditions;

[0053] (3) Lack of universality: Existing automatic calibration schemes are often designed for specific types of sensors (only supporting differential or only supporting single-ended), and cannot be compatible with both single-ended and dual-ended (differential) output angle sensor signal processing.

[0054] like Figure 1 As shown in the figure, this embodiment introduces an automatic calibration method for zero-position deviation of a brushless motor angle sensor, including steps 1100-1400.

[0055] Step 1100: After receiving the calibration command sent by the host computer, put the motor into open-loop control mode.

[0056] The host computer sends calibration commands via XCP (Universal Measurement and Calibration Protocol) or UDS (Unified Diagnostic Services).

[0057] Upon receiving the calibration command, the calibration status of the corner sensor is set to uncalibrated. Specifically, the calibration flag of the corner sensor can be set to 0, indicating that the corner sensor is not calibrated.

[0058] In motor FOC (Field-Oriented Control) control, it is forced into open-loop control mode and no longer reads the actual angle feedback from the angle sensor.

[0059] Step 1200: After the motor speed reaches a stable state in the open-loop control mode, the original ADC value output by the angle sensor is collected.

[0060] Within a 62.5µs torque loop cycle, the motor is driven by a vector voltage with a fixed amplitude (e.g., 0.1F) and a fixed frequency (e.g., 0.003926F step). This is continued for 5 seconds (approximately 80,000 control cycles) to allow the motor speed to stabilize, ensuring stable output signal amplitude from the angle sensor and eliminating electrical transient interference during startup. After speed stabilization, 500 sets of raw ADC (Analog-to-Digital Converter) values ​​from the angle sensor are continuously acquired at 5ms sampling intervals (80 cycles).

[0061] The stabilization time of 5s and the sampling interval of 5ms can be adjusted according to the mechanical time constant of the motor and the signal frequency of the angle sensor. For example, the stabilization time can be changed to 3s or 10s, as long as the signal stability can be guaranteed.

[0062] Step 1300: Calculate the offset and amplitude gain of the angle sensor based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor.

[0063] The raw ADC values ​​output by the angle sensor include the positive terminal output of the sine signal, the positive terminal output of the cosine signal, the negative terminal output of the sine signal, and the negative terminal output of the cosine signal.

[0064] like Figure 2 As shown, This indicates the positive terminal output of a sine wave signal. This indicates the positive output of the cosine signal. This indicates the negative output of a sine wave signal. This represents the negative output of the cosine signal. The four raw analog signals output by the angle sensor include... , , , The sampled raw ADC values ​​together form a set of differential sine and cosine signals, used to calculate the electrical angle of the motor rotor. and To form a sinusoidal differential signal pair, waveform and They are out of phase (i.e., 180° out of phase) but have the same amplitude. Furthermore... and To form a cosine difference signal pair, waveform and The waveforms are 90° out of phase. waveform and The waveform is inverted. Differential output can eliminate common-mode noise, such as power supply fluctuations, ground interference, and temperature drift, thereby improving the signal-to-noise ratio.

[0065] The signal processing modes of the corner sensor include single-ended mode and dual-ended mode. Single-ended mode and dual-ended mode refer to two different processing methods for the raw analog signal of the corner sensor. Single-ended mode and dual-ended mode correspond to different corner sensors. The calibration method in this application is compatible with different corner sensors and can switch processing modes according to actual conditions.

[0066] Specifically, step 1300 includes steps 1310-1320.

[0067] Step 1310: Determine the original sine signal and the original cosine signal based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor.

[0068] The original sine and original cosine signals represent signal values ​​that have undergone preliminary merging or differential processing but have not yet been offset or gain corrected.

[0069] When the signal processing mode of the angle sensor is single-ended, the positive output of the sine signal is determined as the original sine signal, and the positive output of the cosine signal is determined as the original cosine signal.

[0070] In single-ended mode, the positive terminal of the sine wave signal is used directly as the output. The positive terminal output of the cosine signal As the original sine signal and the original cosine signal .

[0071] When the signal processing mode of the angle sensor is in dual-end mode, the original sine signal is determined based on the positive and negative outputs of the sine signal, and the original cosine signal is determined based on the positive and negative outputs of the cosine signal.

[0072] Specifically, the process of determining the original sine signal includes: calculating the difference between the positive and negative outputs of the sine signal; and determining the original sine signal based on the difference between the sine signals.

[0073] In dual-end mode, the angle sensor outputs four signals. and These are a pair of differential signals with equal amplitude, opposite phase, and superimposed with the same common-mode DC bias voltage. Using a differential configuration can eliminate common-mode interference, retaining only the useful differential-mode signal.

[0074] ;

[0075] ;

[0076] in, This is the common-mode bias voltage, such as the midpoint of the ADC range. It is the signal amplitude. The rotor electrical angle is given.

[0077] Will and Subtraction yields the sinusoidal signal difference:

[0078] ;

[0079] It can be seen that the common-mode bias voltage after differential calculation They are completely canceled out, leaving only the original sinusoidal differential signal. This difference value is the original sine signal. .

[0080] Original sine signal Represented as:

[0081] ;

[0082] After difference calculation It is a signed numerical value with a range of variation. It has removed the common-mode bias and contains only pure angle-related sinusoidal information.

[0083] The process of determining the original cosine signal includes: calculating the cosine signal difference based on the positive output and the negative output of the cosine signal; and determining the original cosine signal based on the cosine signal difference.

[0084] The cosine differential signal output by the angle sensor and It also contains a common-mode bias voltage (the same as the sine channel) and is subject to the same common-mode noise. Differential processing can eliminate the common-mode component, retaining only the useful cosine differential signal.

[0085] Step 1320: Calculate the offset and amplitude gain of the angle sensor based on the original sine signal and the original cosine signal.

[0086] Offset refers to the average of the peaks and troughs of the original sine or cosine signal output by the angle sensor. It reflects the DC bias of the angle sensor's output signal and will introduce a first harmonic error in angle calculation. Amplitude gain is used to correct the actual amplitude of the sine and cosine signals to the target amplitude, while ensuring that the amplitudes of the sine and cosine channels are consistent; otherwise, a second harmonic error will occur.

[0087] The actual amplitude refers to the half-peak value of the original sine or cosine signal output by the angle sensor. It reflects the actual strength of the angle sensor signal, and the actual amplitude may vary due to factors such as individual sensor differences, installation tolerances, and temperature changes.

[0088] The target amplitude is the normalized signal amplitude that is expected to be achieved. The actual amplitude may vary between different batches or models of sensors. Normalizing to a uniform target amplitude facilitates subsequent calculations.

[0089] Step 1400: Determine the zero-position deviation based on the offset and amplitude gain of the angle sensor.

[0090] In this embodiment, step 1400 includes steps 1410-1440.

[0091] Step 1410: Control the motor to run according to the set multiple open-loop target angles.

[0092] Three open-loop target angles can be set, including a first target angle, a second target angle, and a third target angle. For example, the first and third target angles can be 0, and the second target angle can be within the range of 0-π. The first, second, and third target angles can also be set to other values, such as the first target angle being 0.33*π, the second target angle being 0.66*π, and the third target angle being 0.99*π.

[0093] The motor operates sequentially according to the first target angle, the second target angle, and the third target angle. Specifically, the motor first moves to the position of the first target angle, then moves from the position of the first target angle to the position of the second target angle, and finally moves from the position of the second target angle to the position of the third target angle.

[0094] Step 1420: When the motor runs to each of the target angles, acquire the angle signal output by the angle sensor corresponding to the target angle.

[0095] After the motor moves to each target angle position and comes to a stop, the angle of the motor at the current position is detected by the angle sensor.

[0096] Step 1430: Calculate the electrical angle corresponding to each target angle by using the angle signal output by the angle sensor corresponding to the target angle, as well as the offset and amplitude gain of the angle sensor.

[0097] The calculation of the actual electrical angle is performed by normalizing the actual difference value under the corresponding target angle based on the normalization parameters, and then obtaining the normalized sine and normalized cosine values ​​under the target angle.

[0098] ;

[0099] ;

[0100] in, For the first Normalized sine value from each target angle Indicates the first The original sinusoidal signal detected by the angle sensor at the target angular position. This is the sinusoidal offset. The amplitude gain of the sinusoidal signal. For the first Normalized cosine value from each target perspective Indicates the first The original cosine signal detected by the angle sensor for each target angular position. This is the cosine offset. This represents the amplitude gain of the cosine signal.

[0101] Then according to and The first tangent is calculated by arctangent. The electrical angle corresponding to each target angle.

[0102] Step 1440: Determine the zero-position deviation based on each of the target angles and the electrical angle corresponding to each of the target angles.

[0103] Specifically, step 1440 includes: calculating the angle deviation between each target angle and the electrical angle corresponding to the target angle; and determining the average value of all angle deviations as the zero deviation.

[0104] For example, the first target angle is 0.33π, the second target angle is 0.66π, and the third target angle is 0.99π. The first electrical angle of the motor at the first target angle position is 0.34π, the second electrical angle of the motor at the second target angle position is 0.69π, and the third electrical angle of the motor at the third target angle position is 1.01π. The first angle difference between the first target angle and the first electrical angle is 0.01π, the second angle difference between the second target angle and the second electrical angle is 0.03π, and the third angle difference between the third target angle and the third electrical angle is 0.02π. Finally, the average value of the first angle difference, the second angle difference, and the third angle difference is 0.02π. Therefore, the angle difference of 0.02π is taken as the zero position deviation.

[0105] This invention utilizes an open-loop voltage vector to drive a motor rotation to obtain the complete waveform characteristics of the sensor, solving the problem of calibration without free rotation in a closed-loop state. Simultaneously, differential processing of the dual-ended signals is implemented at the software level, extracting the common-mode rejection characteristics of the differential signals and improving calibration accuracy. Furthermore, by forcibly pulling the motor to 0 electrical angle and a small nearby angle position, and sampling multiple times and averaging, the physical deviation between the sensor zero position and the motor zero position is accurately captured.

[0106] In this embodiment, the offset of the angle sensor includes a sine offset and a cosine offset, and the amplitude gain of the angle sensor includes the amplitude gain of the sine signal and the amplitude gain of the cosine signal.

[0107] Step 1320 includes steps 1321-1324.

[0108] Step 1321: Determine the maximum value and the minimum value of the original sine signal.

[0109] Step 1322: Determine the sine offset and the amplitude gain of the sine signal based on the maximum value and the minimum value of the original sine signal.

[0110] Calculate the sinusoidal offset using the following formula:

[0111] ;

[0112] in, This is the sinusoidal offset. This represents the maximum value of the original sinusoidal signal. This is the minimum value of the original sinusoidal signal.

[0113] Calculate the amplitude gain of a sinusoidal signal using the following formula:

[0114] ;

[0115] in, This represents the amplitude gain of the sinusoidal signal.

[0116] Step 1323: Determine the maximum value and the minimum value of the original cosine signal.

[0117] Step 1324: Determine the cosine offset and the amplitude gain of the cosine signal based on the maximum value and the minimum value of the original cosine signal.

[0118] Calculate the cosine offset using the following formula:

[0119] ;

[0120] in, This is the cosine offset. This represents the maximum value of the original cosine signal. This is the minimum value of the original cosine signal.

[0121] Calculate the amplitude gain of the cosine signal using the following formula:

[0122] ;

[0123] in, This represents the amplitude gain of the cosine signal. 1024 is the radius of the Lissajous circle.

[0124] The above , , , The parameters are written to EEPROM (Electrically Erasable Programmable Read-Only Memory) for persistent storage and subsequent angle calculations. , , , In dual-ended mode, the value may be negative. Before storing it in EEPROM, it is converted to unsigned type (with additional negative number judgment and negative number flag added) and then stored.

[0125] This embodiment introduces an electronic device, including a processor and a memory. The memory stores programs or instructions that can run on the processor. When the program or instructions are executed by the processor, they implement the steps of an automatic calibration method for zero-position deviation of a brushless motor angle sensor as described in any embodiment of the present invention.

[0126] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention.

[0127] Those skilled in the art will recognize that the modules and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0128] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described apparatus and equipment can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0129] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0130] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0131] In addition, the functional modules in the embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0132] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0133] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

[0134] It should be understood that the sequence numbers of the steps in the invention's content and embodiments do not absolutely imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention. The foregoing description of embodiments of this disclosure has been provided for illustrative and descriptive purposes. The foregoing description is not exhaustive and is not intended to limit this disclosure to the exact form disclosed. Various modifications and variations may exist based on the foregoing teachings, or various modifications and variations may be derived from the practice of this disclosure. These embodiments were chosen and described to illustrate the principles of this disclosure and its practical application, so that those skilled in the art can utilize this disclosure in various implementations and modifications suitable for the specific purpose of the concept.

Claims

1. A method for automatic calibration of zero deviation of a brushless motor rotation angle sensor, characterized in that, include: After receiving the calibration command from the host computer, the motor is put into open-loop control mode; After the motor speed reaches a stable state in the open-loop control mode, the original ADC value output by the angle sensor is collected. The offset and amplitude gain of the angle sensor are calculated based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor. The zero-position deviation is determined based on the offset and amplitude gain of the angle sensor. The step of determining the zero-position deviation based on the offset and amplitude gain of the angle sensor includes: The motor is controlled to operate according to multiple set open-loop target angles; When the motor reaches each of the target angles, the angle signal output by the angle sensor corresponding to the target angle is acquired; The electrical angle corresponding to each target angle is obtained by calculating the angle signal output by the angle sensor corresponding to the target angle, as well as the offset and amplitude gain of the angle sensor. Calculate the normalized sine and normalized cosine values ​​at the target angle: ； ； wherein, is a normalized sine value at the th target angle, represents an original sine signal detected by the rotation angle sensor at the th target angle position, is a sine offset amount, is an amplitude gain of the sine signal, is a normalized cosine value at the th target angle, represents an original cosine signal detected by the rotation angle sensor at the th target angle position, is a cosine offset amount, is an amplitude gain of the cosine signal; according to and The first tangent is calculated by arctangent. The electrical angle corresponding to each target angle; The zero-position deviation is determined based on each target angle and the corresponding electrical angle. Determining the zero-position deviation based on each target angle and the corresponding electrical angle includes: Calculate the angular deviation between each target angle and the corresponding electrical angle; The average value of all angular deviations is determined as the zero deviation.

2. The automatic calibration method for zero-position deviation of a brushless motor angle sensor according to claim 1, characterized in that, The raw ADC value output by the angle sensor includes the positive terminal output of the sine signal, the positive terminal output of the cosine signal, the negative terminal output of the sine signal, and the negative terminal output of the cosine signal. The step of calculating the offset and amplitude gain of the angle sensor based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor includes: The original sine signal and the original cosine signal are determined based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor. The offset and amplitude gain of the angle sensor are calculated based on the original sine and cosine signals.

3. The automatic calibration method for zero-position deviation of a brushless motor angle sensor according to claim 2, characterized in that, The step of determining the original sine and cosine signals based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor includes: When the signal processing mode of the angle sensor is single-ended, the positive output of the sine signal is determined as the original sine signal, and the positive output of the cosine signal is determined as the original cosine signal.

4. The automatic calibration method for zero-position deviation of a brushless motor angle sensor according to claim 2, characterized in that, The step of determining the original sine and cosine signals based on the signal processing mode of the angle sensor and the original ADC value output by the angle sensor includes: When the signal processing mode of the angle sensor is in dual-end mode, the original sine signal is determined based on the positive terminal output and the negative terminal output of the sine signal, and the original cosine signal is determined based on the positive terminal output and the negative terminal output of the cosine signal.

5. The automatic calibration method for zero-position deviation of a brushless motor angle sensor according to claim 4, characterized in that, Determining the original sine signal based on the positive terminal output and the negative terminal output of the sine signal includes: The difference of the sine signal is calculated based on the positive output and the negative output of the sine signal. The original sine signal is determined based on the difference of the sine signal.

6. The automatic calibration method for zero-position deviation of a brushless motor angle sensor according to claim 4, characterized in that, Determining the original cosine signal based on the positive output and the negative output of the cosine signal includes: The cosine signal difference is calculated based on the positive output and the negative output of the cosine signal. The original cosine signal is determined based on the difference of the cosine signal.

7. The automatic calibration method for zero-position deviation of a brushless motor angle sensor according to claim 2, characterized in that, The offset of the angle sensor includes a sine offset and a cosine offset, and the amplitude gain of the angle sensor includes the amplitude gain of the sine signal and the amplitude gain of the cosine signal. The calculation of the offset and amplitude gain of the angle sensor based on the original sine signal and the original cosine signal includes: Determine the maximum value and the minimum value of the original sinusoidal signal; The sine offset and the amplitude gain of the sine signal are determined based on the maximum value and the minimum value of the original sine signal. Determine the maximum value and the minimum value of the original cosine signal; The cosine offset and the amplitude gain of the cosine signal are determined based on the maximum value and the minimum value of the original cosine signal.

8. An electronic device, characterized in that, It includes a processor and a memory, the memory storing programs or instructions that can run on the processor, the programs or instructions being executed by the processor to implement the steps of an automatic calibration method for zero-position deviation of a brushless motor angle sensor as described in any one of claims 1 to 7.

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