Motor position non-contact sensing system and signal processing control method

Abstract

The invention discloses a motor position non-contact sensing system and a signal processing control method. The system comprises a three-dimensional magnet assembly, a magnetic signal acquisition module, a digital signal processing unit, a voltage conversion unit and a cooperative control module. The three-dimensional magnet assembly and the acquisition module are coaxially arranged, magnetic points are in spatial gradient layout, the acquisition module comprises a three-dimensional magnetic field detection unit, a real-time phase calibration unit is arranged in the processing unit, and the cooperative control module adjusts sampling parameters based on the rotating speed. The method comprises the steps of initialization, magnetic signal acquisition, operation processing and voltage conversion output. According to the scheme, the problem of magnetic field signal distortion of an existing system is solved, stable and accurate sensing of the motor position is achieved, and the multi-scene motor control requirement is met.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, specifically to a non-contact motor position sensing system and signal processing control method. Background Technology

[0002] In the field of non-contact motor position sensing, the stability and accuracy of the magnetic field signal directly determine the position detection precision. In existing technologies, the installation of the three-dimensional magnet and the acquisition module lacks precise coaxial positioning design, resulting in uneven spatial attenuation of the magnetic field signal during transmission. Simultaneously, the magnetic points on the magnet surface are mostly uniformly magnetized, failing to form a stable magnetic field gradient distribution, leading to significant fluctuations in the magnetic field signal intensity acquired by the acquisition module. Furthermore, the system lacks a targeted real-time phase calibration mechanism; vibrations and electromagnetic interference during motor operation can cause phase shifts in the magnetic field signal, which cannot be corrected in time. This ultimately leads to distortion of the original magnetic flux acquisition and significant deviations in position calculation, making it difficult to meet the requirements of high-precision motor control scenarios.

[0003] Based on the above problems, there is an urgent need for a technical solution that can solve the problems of uneven magnetic field signal attenuation, phase shift and magnetic flux distortion. Summary of the Invention

[0004] The purpose of this invention is to provide a non-contact motor position sensing system, comprising a three-dimensional magnet assembly, a magnetic signal acquisition module, a digital signal processing unit, a voltage conversion unit, and a collaborative control module. The three-dimensional magnet assembly is disposed at the end of the motor rotor and rotates synchronously with the rotor. The three-dimensional magnet assembly includes a ring magnet base and a 360-degree ring array of magnetic points. The rotation axis of the three-dimensional magnet assembly is coaxially arranged with the detection center of the magnetic signal acquisition module. The magnetic point structure and the magnetic signal acquisition module are arranged in a spatial gradient. The magnetic signal acquisition module is fixed at the corresponding position of the motor stator and is non-contactly opposite to the three-dimensional magnet assembly. The magnetic signal acquisition module has three mutually perpendicular magnetic field detection units built in, which are evenly distributed around the detection center. The digital signal processing unit receives the signal output by the magnetic signal acquisition module and has a built-in real-time phase calibration unit. The voltage conversion unit converts the coordinate signal output by the digital signal processing unit into a voltage signal. The collaborative control module is bidirectionally electrically connected to the above modules and provides synchronous timing control. The collaborative control module adjusts the sampling parameters based on the motor speed.

[0005] Preferably, the magnetic dot structure is composed of uniformly distributed magnetic dots, the magnetization direction of each magnetic dot is pointing to the central axis of the three-dimensional magnet assembly, the magnetic dot structure has a magnetization intensity gradient distribution along the circumferential direction, and the gradient change period matches the number of pole pairs of the motor rotor.

[0006] In a further preferred embodiment, the magnetic signal acquisition module also includes a detection chip integrating three magnetic field detection units, a signal conditioning circuit, an isolation protection circuit, and a temperature self-calibration unit. The signal conditioning circuit amplifies and filters the original magnetic field signal, the isolation protection circuit provides electrical isolation and overvoltage protection, and the temperature self-calibration unit calibrates the temperature drift error of the detection chip.

[0007] In a further preferred embodiment, the digital signal processing unit also includes a processing chip with integrated filtering and arithmetic functions, a buffer unit, and an interface circuit. The buffer unit stores the original signal, the filtered signal, and the phase calibration data. The interface circuit enables signal transmission with other modules, and the real-time phase calibration unit corrects the phase shift of the magnetic field signal.

[0008] Furthermore, preferably, the computational function of the digital signal processing unit is implemented through a magnetic flux cooperative compensation formula, which is as follows:

[0009] ;

[0010] in, The compensated three-dimensional composite magnetic flux has the dimension of Weber (Wb). The original three-dimensional synthetic magnetic flux acquired by the magnetic signal acquisition module is expressed in Weber (Wb). This is the temperature influence coefficient, with dimensions 1 / ℃; The ambient temperature is currently being measured, with the dimension ℃. Standard ambient temperature, in °C; is the external magnetic field interference influence coefficient, with dimensions of 1 / Tesla (1 / T). The current external magnetic field strength is expressed in Tesla (T). The standard external magnetic field strength is expressed in Tesla (T). The historical signal attenuation weighting coefficient has a dimension of 1. The serial number of the historical signal sampling point participating in the compensation, with a dimension of 1; For the first The original three-dimensional composite magnetic flux collected at all times is in Weber (Wb). The current sampling time is expressed in seconds (s). For the first The sampling time is measured in seconds (s). Let be the signal decay time constant, with the dimension of seconds (s).

[0011] More preferably, the digital signal processing unit performs position coordinate transformation based on the compensated magnetic flux using a three-dimensional position coordinate transformation formula. During the coordinate transformation, calibration data from the real-time phase calibration unit is simultaneously invoked. The three-dimensional position coordinate transformation formula is:

[0012] ;

[0013] ;

[0014] ;

[0015] in, , , These are the three-dimensional coordinates of the motor position, in millimeters (mm). , , These are the installation reference angles for the three magnetic field detection units, with the dimension being degrees (°). , , These are the installation offset angles of the magnetic signal acquisition module relative to the motor stator, in degrees (°). , , These are the magnetic flux position transformation coefficients for the three coordinate axes, with dimensions in Weber / mm (Wb / mm). , , These are the coordinate correction coefficients for the three coordinate axes, with dimensions of 1 / Weber (1 / Wb). This is the sequence number of magnetic flux sampling accumulation times during coordinate transformation, with a dimension of 1; For the first The three-dimensional composite magnetic flux after compensation from the subsample is in the dimension of Weber (Wb).

[0016] More preferably, the voltage conversion unit achieves signal output through a voltage signal calibration formula, which is:

[0017] ;

[0018] in, The calibrated voltage signal output by the voltage conversion unit is in the volt (V) dimension. is the overall voltage conversion factor, with dimensions in volts per millimeter (V / mm). , , These are the voltage allocation weighting coefficients corresponding to the three-dimensional position coordinates, with a dimension of 1; The input supply voltage for the voltage conversion unit, in units of volts (V). The standard input supply voltage for the voltage conversion unit, in the dimension of volts (V). This is the input voltage fluctuation correction factor, with dimensions of 1 / volt (1 / V). This is the inherent zero-point offset voltage of the voltage conversion unit, with dimensions in volts (V).

[0019] In a further preferred embodiment, the collaborative control module also includes a status monitoring subunit, a communication interface subunit, and a fault self-diagnosis subunit. The status monitoring subunit collects the operating parameters of each module, the communication interface subunit supports multi-protocol adaptive switching and realizes signal transmission with external terminals, and the fault self-diagnosis subunit detects the operating status of each module in real time and generates fault codes.

[0020] A non-contact motor position sensing signal processing and control method, applied to any one of the above-described non-contact motor position sensing systems, includes the following steps:

[0021] S1. System initialization: The collaborative control module configures the parameters of each module, sets the standard environmental parameters, outputs a synchronous clock signal, and each module enters standby mode;

[0022] S2. Magnetic signal acquisition: The three-dimensional magnet assembly rotates with the rotor, and the magnetic signal acquisition module acquires the three-dimensional magnetic field signal, which is then conditioned and isolated before being transmitted to the digital signal processing unit.

[0023] S3. Signal processing: After the digital signal processing unit reduces the noise of the signal, the real-time phase calibration unit corrects the signal phase shift, and then calculates the compensation magnetic flux through the magnetic flux cooperative compensation formula, and generates the three-dimensional coordinate value of the motor through the three-dimensional position coordinate transformation formula.

[0024] S4. Voltage Conversion Output: The voltage conversion unit converts the coordinate values ​​into voltage signals using a voltage signal calibration formula. The control module monitors the signal stability and transmits the voltage signals to the motor control terminal through the communication interface subunit.

[0025] In a further preferred embodiment, in S3, the original magnetic field signal is evaluated for validity and abnormal signals are removed. The sampling time and magnetic field strength parameters of the abnormal signals are marked. In S4, the collaborative control module dynamically adjusts the sampling frequency according to the motor speed, increasing the sampling frequency when the speed increases and decreasing the sampling frequency when the speed decreases.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The inventive technical points of this invention include the coaxial arrangement of the three-dimensional magnet assembly and the acquisition module, the spatial gradient layout of the magnetic point structure, and the real-time phase calibration unit. These technical points specifically solve the core problems of uneven magnetic field signal attenuation, phase shift, and magnetic flux distortion in the prior art, effectively improving the stability and accuracy of motor position sensing and meeting the requirements of high-precision motor control. Attached Figure Description

[0028] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0029] Figure 1 This is a connection block diagram of the non-contact motor position sensing system of the present invention;

[0030] Figure 2 This is a flowchart of the non-contact sensing signal processing and control method for motor position according to the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] The main technical problems of the existing technology are that the three-dimensional magnet component and the magnetic signal acquisition module are installed on different axes, the magnetic point structure has no spatial gradient layout, and there is no real-time phase calibration mechanism. This leads to uneven spatial attenuation of the magnetic field signal, and the phase shift causes distortion in magnetic flux acquisition, which ultimately affects the accuracy of motor position detection.

[0034] Based on this, such as Figure 1As shown, this embodiment provides a non-contact motor position sensing system, including a three-dimensional magnet assembly, a magnetic signal acquisition module, a digital signal processing unit, a voltage conversion unit, and a collaborative control module. The three-dimensional magnet assembly is disposed at the end of the motor rotor and rotates synchronously with the rotor. The three-dimensional magnet assembly includes a ring magnet base and a 360-degree ring array of magnetic points. The rotation axis of the three-dimensional magnet assembly is coaxially arranged with the detection center of the magnetic signal acquisition module. The magnetic point structure and the magnetic signal acquisition module are arranged in a spatial gradient. The magnetic signal acquisition module is fixed at the corresponding position of the motor stator and is non-contactly opposite to the three-dimensional magnet assembly. The magnetic signal acquisition module has three mutually perpendicular magnetic field detection units built in it, which are evenly distributed around the detection center. The digital signal processing unit receives the signal output by the magnetic signal acquisition module and has a built-in real-time phase calibration unit. The voltage conversion unit converts the coordinate signal output by the digital signal processing unit into a voltage signal. The collaborative control module is bidirectionally electrically connected to the above modules and provides synchronous timing control. The collaborative control module adjusts the sampling parameters based on the motor speed.

[0035] The annular magnet base of the three-dimensional magnet assembly is made of neodymium iron boron permanent magnet material through a hot-pressing process. The thickness of the base is adapted to the installation space at the end of the motor rotor. The magnetic point structure on the surface is formed by laser engraving. The number of magnetic points is configured in a fixed ratio with the number of pole pairs of the motor. For example, an 8-pole motor corresponds to 176 magnetic points. The magnetic points are evenly distributed along the circumference of the annular base. The spatial gradient layout of the magnetic point structure and the magnetic signal acquisition module is specifically reflected in the linear distribution of the magnetization intensity of the magnetic points along the radial direction of the base from the inside to the outside, ensuring that the acquisition module can obtain a stable magnetic field signal at different radial positions. The detection chip of the magnetic signal acquisition module uses the A1395 chip with an integrated three-dimensional Hall effect sensor. Three mutually perpendicular magnetic field detection units correspond to the X-axis, Y-axis, and Z-axis, respectively, and are evenly distributed around the center of the chip at equal angles. The chip is fixed to the end of the motor stator by a custom bracket. During installation, a laser alignment instrument is used for coaxial calibration to ensure that the coaxiality error between the rotation axis of the three-dimensional magnet assembly and the chip detection center is controlled within a very small range, ensuring the uniformity of magnetic field signal transmission. The digital signal processing unit uses the TI TMS320F28335 DSP chip. Its built-in real-time phase calibration unit, through a hardware-level phase comparator, captures the difference between the current magnetic field signal and a preset standard phase template in real time, calculates the phase offset, and generates corresponding calibration coefficients. These calibration coefficients are then superimposed onto the acquired signal in real time, achieving dynamic correction of the phase offset. The collaborative control module uses an STM32H743 microcontroller. Its internal timer generates a high-frequency synchronous clock signal, which is transmitted to the magnetic signal acquisition module, the digital signal processing unit, and the voltage conversion unit, ensuring timing coordination among the modules. Simultaneously, by acquiring the motor speed signal, the sampling frequency parameter is dynamically adjusted; the sampling frequency increases synchronously when the speed increases and decreases accordingly when the speed decreases, balancing real-time detection and resource utilization. The voltage conversion unit uses an AD5754 digital-to-analog converter chip. This chip receives the digital coordinate signal output from the digital signal processing unit and converts it into an analog voltage signal of 0 to 10 volts, adapting to the input signal requirements of mainstream motor controllers.

[0036] The main technical problem with the existing technology is that the magnetization direction of the magnetic points is disordered and the magnetization intensity is irregularly distributed, which leads to insufficient stability in the transmission of magnetic field signals and affects the consistency of magnetic flux acquisition.

[0037] Based on this, the magnetic dot structure is composed of uniformly distributed magnetic dots, and the magnetization direction of each magnetic dot points to the central axis of the three-dimensional magnet assembly. The magnetic dot structure has a magnetization intensity gradient distribution along the circumference, and the gradient change period matches the number of pole pairs of the motor rotor.

[0038] The magnetic dots in the magnetic dot structure are formed on the surface of the annular magnet base using magnetron sputtering. The magnetic dots are circular, with a diameter determined by the motor specifications; for example, a diameter of 2 mm is used for small to medium-sized motors. All magnetic dots are evenly distributed along the outer surface of the annular base, with a standard density of 22 magnetic dots per pole to ensure the continuity of the magnetic field signal. The magnetization direction of each magnetic dot is precisely controlled by a directional magnetization device. During magnetization, a central positioning fixture is used to ensure that the magnetization direction of each magnetic dot strictly points to the central axis of the three-dimensional magnet assembly, avoiding signal interference caused by magnetic field direction deviation. Specifically, the magnetization intensity gradient distribution along the circumference of the magnetic dot structure is as follows: the initial magnetization intensity is set to 1.2 Tesla, and it gradually decreases linearly to 1.0 Tesla along the circumference in a gradient cycle before entering the next gradient cycle. The gradient cycle strictly matches the number of pole pairs of the motor rotor; for example, the gradient cycle for a 4-pole motor is 90 degrees, ensuring that the magnetic signal acquisition module can continuously acquire a stable and changing magnetic field signal during motor rotor rotation.

[0039] The main technical problem with existing technologies is that during the magnetic signal acquisition process, the original signal is easily affected by high-frequency noise, voltage fluctuations, temperature drift and external circuit interference, which leads to signal distortion and affects the accuracy of subsequent processing.

[0040] Based on this, the magnetic signal acquisition module also includes a detection chip integrating three magnetic field detection units, a signal conditioning circuit, an isolation protection circuit, and a temperature self-calibration unit. The signal conditioning circuit amplifies and filters the original magnetic field signal, the isolation protection circuit realizes electrical isolation and overvoltage protection, and the temperature self-calibration unit calibrates the temperature drift error of the detection chip.

[0041] The detection chip integrating three magnetic field detection units is model A1395. This chip outputs an analog magnetic field signal ranging from 0 to 3.3 volts. The signal conditioning circuit consists of an AD8221 operational amplifier and an RC low-pass filter. The AD8221 operational amplifier amplifies the weak original signal output by 10 times, ensuring the signal amplitude meets the requirements of subsequent processing. The RC low-pass filter has a resistance of 10 kΩ and a capacitance of 10 NF, with a cutoff frequency of approximately 1.6 kHz, effectively filtering out high-frequency electromagnetic noise generated by the motor operation. The isolation protection circuit uses a TLP181 optocoupler to achieve electrical isolation between the detection chip and the subsequent digital signal processing unit. The isolation voltage is not less than 2500 volts RMS. Simultaneously, an SMBJ3.3CA overvoltage protection diode is connected in series at the power input terminal of the detection chip. When the input voltage exceeds 3.6 volts, the diode breaks down and conducts, protecting the detection chip from damage due to excessive voltage. The temperature self-calibration unit includes a DS18B20 temperature sensor and a calibration logic circuit. The DS18B20 temperature sensor collects the ambient temperature around the detection chip in real time, with a sampling interval set to 500 milliseconds. The calibration logic circuit has a built-in preset temperature drift calibration coefficient table. Based on the collected temperature value, it looks up the corresponding calibration coefficient, generates a temperature drift compensation value, and adds it to the original signal output by the detection chip in real time to dynamically calibrate the error caused by temperature drift.

[0042] The main technical problems with existing technologies are that there is a lack of a dedicated phase calibration mechanism in the digital signal processing process, which makes it impossible to correct the phase shift of the magnetic field signal. Furthermore, the data storage is not managed in a targeted manner, and abnormal data can easily enter the calculation process, affecting the processing accuracy.

[0043] Based on this, the digital signal processing unit also includes a processing chip with integrated filtering and arithmetic functions, a buffer unit, and an interface circuit. The buffer unit stores the original signal, the filtered signal, and the phase calibration data. The interface circuit enables signal transmission with other modules, and the real-time phase calibration unit corrects the phase shift of the magnetic field signal.

[0044] The processing chip used is the TMS320F28335DSP chip, which has a built-in 16-bit ADC module with a sampling rate of 12.5 megasamples per second. This allows for rapid reception of the conditioned signal output from the magnetic signal acquisition module. The chip's integrated filtering function uses an infinite impulse response low-pass filter with a cutoff frequency set to 1 kHz to further filter out residual high-frequency interference signals. The real-time phase calibration unit is implemented collaboratively by the chip's internal comparator and timer modules. The comparator module compares the currently received magnetic field signal with a standard phase template pre-stored in ROM. The standard phase template is the phase curve of the ideal magnetic field signal at the motor's rated speed. The phase offset is calculated through this comparison. The timer module generates calibration pulses based on the phase offset, dynamically adjusting the signal sampling timing to achieve real-time correction of the phase offset, maintaining a high level of calibration accuracy. The cache unit uses an IS61LV25616 SRAM chip with a capacity of 4 megabytes. The chip is internally divided into three independent storage areas: the original signal, the filtered signal, and phase calibration data, respectively. Each storage area has an equal allocation of storage space. When the signal processing subunit detects that the signal value at a certain sampling point exceeds the normal range, it triggers an abnormal data locking mechanism, marking the relevant data at that sampling point as abnormal and locking it to prevent it from participating in subsequent processing. The interface circuit uses an AD7689 SPI interface chip with an SPI clock frequency set to 10 MHz, enabling bidirectional high-speed data transmission between the processing chip, the voltage conversion unit, and the collaborative control module, with a transmission delay of no more than 1 microsecond.

[0045] The main technical problem with the existing technology is that the original three-dimensional synthesized magnetic flux is easily affected by changes in ambient temperature, external magnetic field interference, and attenuation of historical sampling signals, which leads to distortion of magnetic flux data and failure to accurately reflect the position of the motor rotor, thus causing deviations in subsequent position calculations.

[0046] Based on this, the computational function of the digital signal processing unit is realized through the magnetic flux cooperative compensation formula, which is as follows:

[0047] ;

[0048] in, The compensated three-dimensional composite magnetic flux has the dimension of Weber; The original three-dimensional composite magnetic flux, in Weber dimension, is acquired by the magnetic signal acquisition module. It is obtained by multiplying the magnetic field strength acquired by the X-axis, Y-axis, and Z-axis magnetic field detection units by the corresponding effective area and then calculating it through vector synthesis. This is the temperature influence coefficient, with dimensions of 1 per degree Celsius, which is determined to be -0.002 per degree Celsius based on the material properties of neodymium iron boron magnets. The current ambient temperature is measured in degrees Celsius and is provided by the temperature self-calibration unit of the magnetic signal acquisition module. The standard ambient temperature is measured in degrees Celsius and is set to 25 degrees Celsius. The external magnetic field interference influence coefficient has a dimension of 1 per Tesla and is determined to be 0.05 per Tesla through calibration experiments under a standard external magnetic field. The current external magnetic field strength, measured in Tesla, is collected by an independently deployed external magnetic field sensor. The standard external environmental magnetic field strength, in the dimension of Tesla, is set to 0.0005 Tesla, i.e., the geomagnetic field strength; The historical signal attenuation weighting coefficient, with a dimension of 1, was determined to be 0.15 through numerous experiments on signal attenuation characteristics. The historical signal sampling point number that participates in the compensation is dimensionless and ranges from 1 to 5; The original three-dimensional composite magnetic flux collected at time n-1 is expressed in Weber. The current sampling time is expressed in seconds. The sampling time is at time n-1, and its unit is seconds; The signal decay time constant is measured in seconds and is determined to be 0.1 seconds by the signal decay curve fitting experiment.

[0049] The theoretical design of this formula is based on three core error sources in the magnetic flux acquisition process: first, the magnetic permeability of the magnet material fluctuates linearly with changes in ambient temperature; second, stray magnetic fields in the external environment superimpose on the magnetic field of the three-dimensional magnet components; and third, the continuously sampled historical magnetic flux signal is attenuated due to the transient effects of capacitance and inductance in the circuit. If these errors are not specifically corrected, the original magnetic flux will not accurately reflect the motor rotor position. The formula is divided into two parts: the first part is a real-time error correction term, and the second part is a historical signal attenuation compensation term. These two parts work together to achieve full-dimensional error correction. In the specific calculation implementation, the TMS320F28335DSP chip of the digital signal processing unit first reads the current original three-dimensional synthetic magnetic flux through the interface circuit. Current ambient temperature Current external magnetic field strength and the original three-dimensional composite magnetic flux from the previous 5 historical samples The parameters are then calculated step-by-step according to the formula. First, the real-time error correction term is calculated to correct the errors caused by temperature fluctuations and the superposition of external magnetic fields. Then, the historical signal attenuation compensation term is calculated to compensate for the attenuation error of the historical signal caused by transient effects. Finally, the compensated three-dimensional composite magnetic flux is obtained. The calculation cycle is consistent with the magnetic signal sampling cycle, both being 100 microseconds. The calculation results are stored in the corresponding area of ​​the cache unit, providing accurate data support for subsequent position coordinate transformation.

[0050] The core design goal of this formula is to systematically correct multi-source errors in the magnetic flux acquisition process. Its theoretical foundation stems from the basic principles of magnetism, the law of magnetic field superposition, and the theory of transient circuit analysis, fully conforming to the technical logic and reasonable improvement principles of non-contact motor position sensing. The formula is not simply a superposition of error correction terms, but rather, based on the physical nature of error generation, it achieves precise correction through layered compensation, ensuring that the compensated magnetic flux accurately reflects the motor rotor position and provides reliable data support for subsequent coordinate transformation.

[0051] Analysis of error sources reveals three core issues in magnetic flux acquisition: First, the permeability of permanent magnet materials fluctuates linearly with ambient temperature, causing the magnetic induction intensity to deviate from the ideal value. Second, stray magnetic fields in the external environment (such as electromagnetic interference generated by equipment around the motor) can superimpose with the magnetic field of the three-dimensional magnet assembly, altering the actual magnetic field strength at the detection point. Third, during continuous sampling, the capacitors and inductors in the signal conditioning circuit exhibit transient responses, causing historical sampled signals to decay exponentially over time, affecting the accuracy of the current signal. Based on these three major error sources, the formula naturally consists of two parts: a real-time error correction term and a historical signal attenuation compensation term, forming a comprehensive compensation logic.

[0052] Real-time error correction term The derivation process follows the core laws of magnetism: based on the direct proportionality between the magnetic induction intensity and the permeability of a magnet ( The permeability of permanent magnet materials such as neodymium iron boron With temperature The temperature varies linearly, therefore a temperature effect coefficient is introduced. ,pass Calculate the deviation between the current temperature and the standard temperature, and then... The original magnetic flux is linearly corrected in the form of [a specific method / mechanism] to ensure the stability of the magnetic flux under temperature fluctuations. To address external magnetic field interference, based on the principle of magnetic field superposition, the external magnetic field [is used / is corrected / corrected]. It will superimpose with the magnet's own magnetic field to form a total magnetic field, therefore through The deviation between the current external magnetic field and the standard geomagnetic field is calculated and incorporated into the formula using a linear correction method to counteract the superposition effect of stray magnetic fields. These two corrections are combined with the original magnetic flux through a multiplicative approach to ensure that the corrected signal retains the core location information of the original magnetic flux while eliminating environmental interference.

[0053] Historical signal attenuation compensation item The design is based on circuit transient analysis theory. The capacitors and inductors in the signal conditioning circuit constitute a transient system similar to an RC circuit. The attenuation law of the historical sampled signal is consistent with the discharge process of the RC circuit, conforming to the exponential decay characteristic. .in, As a time constant, it is determined by the RC parameters of the circuit and is used to accurately describe the signal attenuation rate; The time interval between the current moment and the historical sampling moments is used to ensure the timeliness of the attenuation calculation. The summation of the first 5 historical sampling points is a balanced choice based on experimental verification—it avoids the random error of a single historical point, and does not cause calculation delay due to too many sampling points, thus balancing compensation accuracy and real-time performance. As a weighting coefficient, its value is determined through fitting a large amount of experimental data. Its core function is to balance the compensation of historical signals with the authenticity of current signals, avoid over-compensation leading to magnetic flux distortion, and ensure that the compensation term only plays the role of smoothing transient errors.

[0054] The main technical problem with the existing technology is that the phase calibration data is not combined during the position coordinate transformation process. The phase shift of the magnetic field signal directly leads to the deviation of the coordinate calculation. Furthermore, the random fluctuation of multiple magnetic flux sampling is not considered, resulting in insufficient coordinate calculation accuracy.

[0055] Based on this, the digital signal processing unit performs position coordinate transformation using the three-dimensional position coordinate transformation formula based on the compensated magnetic flux. During the coordinate transformation, the calibration data from the real-time phase calibration unit is called simultaneously. The three-dimensional position coordinate transformation formula is:

[0056] ;

[0057] in, , , These are the three-dimensional coordinates of the motor's position, in millimeters. The compensated three-dimensional composite magnetic flux has the dimension of Weber; , , These are the installation reference angles for the three magnetic field detection units, measured in degrees, and determined by the installation process. The X-axis detection unit... Set to 0 degrees, Y-axis detection unit The Z-axis detection unit is set to 90 degrees. Set to 180 degrees; , , These are the installation offset angles of the magnetic signal acquisition module relative to the motor stator, measured in degrees, and dynamically corrected by calibration data provided by the real-time phase calibration unit. , , These are the magnetic flux position transformation coefficients for the three coordinate axes, with dimensions in Weber per millimeter, determined through numerous calibration experiments. The value is 0.002 Weber per millimeter. , Values ​​and Maintain consistency; , , These are the coordinate correction coefficients for the three coordinate axes, with a dimension of 1 per Weber, which were determined to be 0.031 per Weber through experimental fitting. This is the sequence number of magnetic flux sampling accumulation times for coordinate transformation, with a dimension of 1 and a value range of 1 to 10; Let be the compensated three-dimensional composite magnetic flux of the i-th sampling, with dimensions in Weber.

[0058] The theoretical design of this formula is based on the spatial correlation between magnetic flux and motor position. The three-dimensional position of the motor rotor determines the relative spatial position of the three-dimensional magnet assembly and the magnetic signal acquisition module, thus affecting the acquired compensated magnetic flux. The two are approximately inversely proportional, but due to factors such as the installation angle deviation of the detection unit and the fluctuation of signals from multiple samplings, multi-dimensional corrections are required through the formula. The numerator of the formula mainly realizes the spatial projection correction of the magnetic field components, based on the principle of vector mechanics, through... Will The magnetic flux component is corrected to be along the mounting reference direction of the detection unit, and then... The projection error caused by the installation offset angle is corrected to ensure the accuracy of the correspondence between the magnetic flux components and the motor position. The denominator mainly realizes the dynamic adjustment of the conversion coefficient and signal smoothing. Based on the statistical error theory, the compensated cumulative magnetic flux value of the first 10 samples is introduced to offset the influence of random fluctuations in a single sample. This is used to balance the impact of the accumulation term on the conversion result, avoiding position calculation errors due to excessively large accumulation values. In specific implementation, the DSP chip of the digital signal processing unit first calls the output of the real-time phase calibration unit. , , The value is then read. and the first 9 samples The accumulated value is calculated. Then, substitute each parameter into the corresponding formula and calculate accordingly. , , The entire calculation process takes no more than 50 microseconds, and the calculation results are transmitted to the voltage conversion unit.

[0059] The core design goal of this formula is to accurately convert the compensated magnetic flux into the three-dimensional coordinates of the motor position, while simultaneously offsetting the effects of installation errors and random sampling fluctuations. Its theoretical basis stems from the spatial correlation characteristics of magnetic flux and position, the principle of vector mechanics projection, and statistical error theory, perfectly aligning with the technical logic of "signal-position" conversion in non-contact sensing. The formula's construction revolves around "precise mapping + error cancellation," with each part addressing a specific technical challenge to ensure the accuracy and stability of the coordinate transformation.

[0060] From the inherent relationship between magnetic flux and position, the three-dimensional position of the motor rotor directly determines the relative spatial distance between the three-dimensional magnet assembly and the acquisition module, with an approximately inverse relationship—the closer the positions, the greater the magnetic flux; the farther the positions, the smaller the magnetic flux. However, this relationship is not ideally linear and is affected by two key factors: first, the installation angle deviation of the detection unit (including reference angle deviation and offset angle); and second, the random fluctuation of a single sampling. Therefore, the derivation of the formula starts by counteracting these two interferences, constructing the conversion logic by dividing the numerator and denominator.

[0061] Molecular part The design is based on the principle of angle projection in vector mechanics. The installation reference angle of the detection unit is essentially the angle between the sensing shaft of the detection unit and the reference plane of the motor stator. Since perfect alignment cannot be achieved during actual installation, the collected magnetic flux is the projection of the magnet's magnetic field onto the sensing shaft. Therefore, through... The compensated magnetic flux The correction is made to the effective components along the reference direction to ensure that the correspondence between the magnetic field components and the position is not affected by the installation reference deviation. The installation offset angle of the acquisition module relative to the motor stator is provided by the real-time phase calibration unit. This offset angle originates from installation process errors (such as bracket deformation and alignment deviation), which will cause a further shift in the magnetic field projection direction. Therefore, it is obtained by... A secondary correction is performed—the sine function is chosen because the installation offset angle is usually a small angle (less than 10°). The sine value is approximately linear with the angle value and can effectively compensate for the projection error caused by the radial offset, ensuring the accuracy and ease of angle correction.

[0062] denominator The design is based on statistical error theory, and its core purpose is to offset the random fluctuations of a single sampling. As the fundamental magnetic flux-position conversion coefficient, it is determined by both the magnet's magnetic strength and the sensitivity of the detection unit, and is the core parameter for realizing the conversion of magnetic flux to position. However, a single conversion coefficient cannot cope with random interference during the sampling process (such as instantaneous fluctuations in magnetic flux caused by electromagnetic noise). Therefore, the compensated cumulative magnetic flux value from the first 10 samples is introduced. The statistical averaging effect of multiple samplings smooths out the impact of fluctuations. As a correction factor, its value is determined through experimental fitting. Its function is to balance the influence of the cumulative term on the conversion result, avoid the position calculation being too small due to the excessively large cumulative value, ensure that the overall trend of the denominator matches the trend of the numerator, and maintain the physical rationality of the formula.

[0063] The main technical problem with the existing technology is that during the voltage conversion process, fluctuations in the input power supply voltage will cause changes in the conversion gain, and the inherent zero-point offset of the unit will produce a fixed error. Both of these factors together cause the output voltage signal to be distorted, making it impossible to accurately reflect the motor position information.

[0064] Based on this, the voltage conversion unit achieves signal output through a voltage signal calibration formula, which is:

[0065] ;

[0066] in, The calibrated voltage signal output by the voltage conversion unit is measured in volts. The total voltage conversion factor, in units of volts per millimeter, was determined to be 0.05 volts per millimeter through a full-stroke calibration experiment. , , These are the voltage allocation weighting coefficients corresponding to the three-dimensional position coordinates, with a dimension of 1, set according to the motor position control requirements. It is 0.4. It is 0.3. It is 0.3, and ; , , These are the three-dimensional coordinates of the motor's position, in millimeters. The input voltage fluctuation correction factor, with a dimension of 1 per volt, is determined to be 0.021 per volt by experimental fitting of the power supply characteristics of the voltage conversion unit. The input supply voltage for the voltage conversion unit, measured in volts, is collected by the status monitoring subunit of the collaborative control module. The standard input supply voltage for the voltage conversion unit, in volts, is set to 5 volts. This is the inherent zero-point offset voltage of the voltage conversion unit, in volts, which was measured to be 0.03 volts through a zero-input calibration experiment.

[0067] The theoretical basis of this formula stems from two core errors in the voltage conversion process: changes in conversion gain caused by fluctuations in the input supply voltage and inherent zero-point offset in the hardware circuit. The formula achieves precise calibration through the coordinated action of three parts. The first part is the coordinate synthesis term. The first part assigns weights to different coordinates based on the actual needs of motor control, highlighting the impact of key coordinates on control accuracy; the second part is the power supply fluctuation correction item. Based on the electrical characteristics of the digital-to-analog converter chip, the gain deviation caused by input voltage fluctuations is dynamically corrected; the third part is the zero-point offset compensation item. This process eliminates the inherent zero-point offset of the hardware circuitry, ensuring the accuracy of the voltage signal. In practice, the AD5754 digital-to-analog converter chip in the voltage conversion unit first reads the signal through an interface. , , and The parameters are calculated step-by-step according to the formula. First, the coordinate composite value is calculated, then multiplied by the total voltage conversion coefficient to obtain the base voltage signal. Next, the influence of input voltage fluctuation is corrected, and finally, the zero-point offset voltage is subtracted to obtain the calibrated output voltage signal. It has a conversion rate of 1 megasamples per second, an output voltage range of 0 to 10 volts, and is compatible with the input requirements of motor controllers.

[0068] The core design goal of this formula is to accurately convert the three-dimensional position coordinates of the motor into an analog voltage signal suitable for the motor controller, while systematically offsetting errors caused by input power supply fluctuations and inherent zero-point offsets in the hardware circuit. Its theoretical basis stems from the electrical characteristics of the digital-to-analog converter chip, the inherent physical characteristics of the hardware circuit, and the actual needs of motor control, conforming to the technical principles and reasonable improvement directions of voltage conversion. The formula is constructed around the linear correlation between coordinates and voltage, and through layered calibration, it ensures that the output voltage accurately reflects the motor position, providing precise signal support for motor control.

[0069] The derivation of the formula begins with the practical needs of motor control: motor controllers typically only receive analog voltage signals of 0-10V, while three-dimensional position coordinates ( , , The impact of radial position on control accuracy varies, therefore, a reasonable coordinate synthesis logic needs to be constructed first. Based on the mechanical characteristics of motor operation, the radial position ( The influence of rotor neutrality is most critical, axial position ( ) and circumferential position ( The impact is secondary, therefore the design weighting coefficients are... , , and satisfy ,pass The weighted synthesis of coordinates highlights the influence of core coordinates while also taking into account the contributions of secondary coordinates, ensuring that the synthesized coordinate signal comprehensively reflects the actual position state of the motor. This design is not based on subjective weight allocation, but rather on a reasonable solution derived from extensive experimental verification based on engineering practice in motor control.

[0070] The theoretical basis for error correction due to input power supply fluctuations is the electrical characteristics of the digital-to-analog converter chip: the chip's conversion gain is linearly related to the input power supply voltage. When the power supply voltage deviates from the standard value... As the input voltage fluctuates, the gain changes, causing output voltage fluctuations. Therefore, an input voltage fluctuation correction factor is introduced. ,pass Calculate the supply voltage deviation, and then... The synthesized coordinate signal is linearly corrected in the form of a logic that conforms to the gain variation law of a linear circuit. The value of is determined by fitting the gain change curve under different supply voltages through experimental measurement to ensure that the influence of power supply fluctuations on the output voltage can be accurately offset.

[0071] The theoretical basis for correcting the inherent zero-point offset of hardware circuits is the inherent physical characteristics of the hardware circuits: even if the input is zero, components such as operational amplifiers and digital-to-analog converters in the voltage conversion unit will still have a slight zero-point offset voltage at the output. This offset will cause a fixed error in the output voltage, which must be deducted. The value is obtained through a zero-input calibration experiment, that is, when all three-dimensional coordinates are zero, the output voltage of the voltage conversion unit is measured, and this voltage is the inherent zero-point offset, which is determined by the formula at the end of the equation. Direct subtraction is achieved, ensuring that the zero position corresponds to the zero voltage reference.

[0072] As the overall voltage conversion coefficient, its design is based on the input voltage range of the motor controller and the maximum stroke position of the motor: through calibration experiments, the motor rotor is moved to the maximum stroke position, the corresponding composite coordinate value is measured, and then fitted according to the controller's maximum input voltage (e.g., 10V) to obtain the final value. This ensures that the output voltage corresponding to the maximum synthesized coordinate value is equal to the maximum input voltage of the controller, thus achieving a linear mapping between coordinates and electricity.

[0073] The main technical problems of the existing technology are that the collaborative control module lacks multi-protocol adaptive communication capabilities, fault diagnosis has no clear coding output, and the timing allocation and status monitoring functions are imperfect, which affects the overall coordination of the system and the efficiency of fault diagnosis.

[0074] Based on this, the collaborative control module includes a timing control subunit, a status monitoring subunit, a communication interface subunit, and a fault self-diagnosis subunit. The timing control subunit provides a synchronous clock and sampling operation timing allocation. The status monitoring subunit collects the working parameters of each module. The communication interface subunit supports multi-protocol adaptive switching to realize signal transmission with external terminals. The fault self-diagnosis subunit detects the working status of each module in real time, generates fault codes, and outputs them through the communication interface subunit.

[0075] The collaborative control module is based on the STM32H743 microcontroller. The timing control subunit generates a 10 MHz synchronous clock signal through the TIM1 timer inside the microcontroller. After being amplified by the 74HC244 buffer, the clock signal is transmitted to the detection chip of the magnetic signal acquisition module, the DSP chip of the digital signal processing unit, and the digital-to-analog converter chip of the voltage conversion unit to ensure the timing synchronization of each module. The TIM2 timer generates a sampling timing signal to control the sampling interval of the magnetic signal acquisition module. The sampling interval is dynamically adjusted according to the motor speed. For example, the sampling interval is 100 microseconds per minute when the speed is 1000 rpm, and it is adjusted to 50 microseconds per minute when the speed is 2000 rpm. The status monitoring subunit acquires operating parameters of each module through the microcontroller's ADC1 interface. The acquisition channels include the operating current of the magnetic signal acquisition module (range 0-100 mA), the power supply voltage of the digital signal processing unit (range 3-3.6 volts), and the output voltage of the voltage conversion unit (range 0-10 volts). The sampling resolution is 12 bits, and the sampling interval is set to 100 milliseconds. The acquired data is stored in the microcontroller's internal FLASH memory. The communication interface subunit integrates a CAN controller and a UART controller. The CAN controller supports the CAN 2.0 protocol, with baud rates adaptively switching between 125 kilobits per second and 1 megabit per second. The UART controller supports adaptive baud rates from 9600 bits per second to 115200 bits per second. By detecting the baud rate of the received data, it automatically matches the communication parameters, achieving compatible communication with different external terminals. The fault self-diagnosis subunit has built-in preset normal operating parameter ranges for each module. When the parameters collected by the status monitoring subunit exceed the preset range and the duration reaches 50 milliseconds, the corresponding module is determined to be faulty, and an 8-bit fault code is generated. The first 3 bits of the code represent the faulty module: 001 represents the magnetic signal acquisition module, 010 represents the digital signal processing unit, 011 represents the voltage conversion unit, and 100 represents the collaborative control module. The last 5 bits represent the fault type: 00001 represents abnormal current, 00010 represents abnormal voltage, 00100 represents signal loss, 01000 represents phase offset exceeding the limit, and 10000 represents communication failure. The fault code is transmitted to the external terminal in real time through the communication interface subunit.

[0076] The main technical problem with existing technologies is that non-contact motor position sensing methods lack system initialization pre-detection, synchronous calibration of acquired signals, and synchronous fault monitoring. The steps are not connected, which affects sensing accuracy and system reliability.

[0077] Based on this, such as Figure 2 As shown, this embodiment provides a non-contact motor position sensing signal processing and control method, applied to any of the above-described non-contact motor position sensing systems, including the following steps:

[0078] S1. System initialization: The collaborative control module configures the parameters of each module, sets the standard environmental parameters, outputs a synchronous clock signal, and each module enters standby mode;

[0079] S2. Magnetic signal acquisition: The three-dimensional magnet assembly rotates with the rotor, and the magnetic signal acquisition module acquires the three-dimensional magnetic field signal, which is then conditioned and isolated before being transmitted to the digital signal processing unit.

[0080] S3. Signal processing: After the digital signal processing unit reduces the noise of the signal, the real-time phase calibration unit corrects the signal phase shift, and then calculates the compensation magnetic flux through the magnetic flux cooperative compensation formula, and generates the three-dimensional coordinate value of the motor through the three-dimensional position coordinate transformation formula.

[0081] S4. Voltage Conversion Output: The voltage conversion unit converts the coordinate values ​​into voltage signals using a voltage signal calibration formula. The control module monitors the signal stability and transmits the voltage signals to the motor control terminal through the communication interface subunit.

[0082] S1. In the system initialization step, after the collaborative control module is powered on, it first reads the default parameters stored in the internal FLASH memory, configures the initial sampling frequency of the magnetic signal acquisition module to 10 kHz, the filtering cutoff frequency of the digital signal processing unit to 1 kHz, and the output range of the voltage conversion unit to 0 to 10 volts. It also sets standard environmental parameters such as a standard ambient temperature of 25 degrees Celsius, a standard external ambient magnetic field strength of 0.0005 Tesla, and a standard input power supply voltage of 5 volts. Subsequently, it outputs a 10 MHz synchronous clock signal. After receiving the clock signal, each module completes its own initialization, enters standby mode, and waits for the start command. S2. In the magnetic signal acquisition step, the motor rotor rotates, driving the three-dimensional magnet assembly to rotate synchronously. The detection chip of the magnetic signal acquisition module acquires the three-dimensional magnetic field signals of the X, Y, and Z axes according to the set sampling frequency. The raw signals are amplified and filtered by the signal conditioning circuit, and then transmitted to the digital signal processing unit through the isolation protection circuit. The transmission delay is controlled within 10 microseconds. Simultaneously, the temperature self-calibration unit acquires the ambient temperature in real time, generates a temperature calibration value, and transmits it to the digital signal processing unit. In the S3 signal processing step, the filtering subunit of the digital signal processing unit performs infinite impulse response low-pass filtering on the received signal to remove high-frequency interference. The real-time phase calibration unit calls the standard phase template to correct the phase shift of the magnetic field signal. Then, it calculates the original three-dimensional composite magnetic flux based on the acquired original magnetic field signal, substitutes it into the magnetic flux collaborative compensation formula to calculate the compensated three-dimensional composite magnetic flux, and then substitutes the compensated magnetic flux into the three-dimensional position coordinate transformation formula to generate the three-dimensional coordinate values ​​of the motor position. , , After the calculation is completed, the coordinate values ​​are transmitted to the voltage conversion unit through the interface circuit. In the voltage conversion output step S4, the digital-to-analog converter chip of the voltage conversion unit receives the three-dimensional coordinate values, substitutes them into the voltage signal calibration formula to calculate the calibrated voltage signal, and outputs it after signal amplification. The status monitoring subunit of the collaborative control module collects the output voltage in real time and monitors the signal stability. The communication interface subunit transmits the voltage signal to the motor control terminal, and the transmission period is consistent with the sampling period.

[0083] The main technical problems of the existing technology are that abnormal signals are not removed during signal processing, and the sampling frequency is fixed and does not adjust with the rotation speed, resulting in large calculation errors, insufficient real-time performance at high speeds or waste of resources at low speeds.

[0084] Based on this, in S3, the validity of the original magnetic field signal is judged and abnormal signals are eliminated, and the sampling time and magnetic field strength parameters of the abnormal signals are marked; in S4, the collaborative control module dynamically adjusts the sampling frequency according to the motor speed, increasing the sampling frequency when the speed increases and decreasing the sampling frequency when the speed decreases.

[0085] In the S3 signal processing step, before the digital signal processing unit performs noise reduction on the original magnetic field signal, it first performs a signal validity judgment. The normal range of magnetic field signals for each axis is preset to be 0.2 to 1.0 Tesla. If the signal value of a certain axis exceeds this range, it is determined to be an abnormal signal. The processing chip records the sampling time of the abnormal signal, accurate to 1 microsecond, and the corresponding magnetic field strength parameter, stores it in the abnormal data area of ​​the cache unit and locks it. At the same time, the signal value of the previous normal sampling point is used to replace the abnormal signal and participate in subsequent filtering, phase calibration, magnetic flux calculation and other calculation processes to avoid the interference of abnormal data on the calculation results. In step S4, the voltage conversion output step, the collaborative control module obtains the real-time motor speed through communication with the motor controller and presets the sampling frequency adjustment rules: when the speed does not exceed 50% of the rated motor speed, the sampling frequency is set to 5 kHz; when the speed exceeds 50% but does not exceed 100% of the rated speed, the sampling frequency is set to 10 kHz; when the speed exceeds 100% but does not exceed 120% of the rated speed, the sampling frequency is set to 15 kHz. The sampling frequency adjustment range is 5 to 15 kHz. The collaborative control module transmits the adjusted sampling frequency command to the magnetic signal acquisition module through the SPI interface. After receiving the command, the module completes the sampling frequency switching within 100 microseconds to ensure real-time detection at high speeds and resource utilization at low speeds.

[0086] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A non-contact motor position sensing system, comprising a three-dimensional magnet assembly, a magnetic signal acquisition module, a digital signal processing unit, a voltage conversion unit, and a cooperative control module, characterized in that, A three-dimensional magnet assembly is positioned at the end of the motor rotor and rotates synchronously with the rotor. The three-dimensional magnet assembly includes a ring magnet base and a 360-degree ring array of magnetic points. The rotation axis of the three-dimensional magnet assembly is coaxially aligned with the detection center of the magnetic signal acquisition module. The magnetic point structure and the magnetic signal acquisition module are arranged in a spatial gradient. The magnetic signal acquisition module is fixed at the corresponding position on the motor stator and is non-contactly positioned relative to the three-dimensional magnet assembly. The magnetic signal acquisition module has three mutually perpendicular magnetic field detection units built in, which are evenly distributed around the detection center. A digital signal processing unit receives the signal output by the magnetic signal acquisition module and has a built-in real-time phase calibration unit. A voltage conversion unit converts the coordinate signal output by the digital signal processing unit into a voltage signal. A collaborative control module is bidirectionally electrically connected to the above modules and provides synchronous timing control. The collaborative control module adjusts the sampling parameters based on the motor speed.

2. The non-contact motor position sensing system according to claim 1, characterized in that, The magnetic dot structure consists of uniformly distributed magnetic dots, with the magnetization direction of each magnetic dot pointing towards the central axis of the three-dimensional magnet assembly. The magnetic dot structure exhibits a gradient distribution of magnetization intensity along the circumference, and the gradient change period matches the number of pole pairs of the motor rotor.

3. The non-contact motor position sensing system according to claim 1, characterized in that, The magnetic signal acquisition module also includes a detection chip integrating three magnetic field detection units, a signal conditioning circuit, an isolation protection circuit, and a temperature self-calibration unit. The signal conditioning circuit amplifies and filters the original magnetic field signal, the isolation protection circuit realizes electrical isolation and overvoltage protection, and the temperature self-calibration unit calibrates the temperature drift error of the detection chip.

4. The non-contact motor position sensing system according to claim 1, characterized in that, The digital signal processing unit also includes a processing chip with integrated filtering and arithmetic functions, a buffer unit, and an interface circuit. The buffer unit stores the original signal, the filtered signal, and the phase calibration data. The interface circuit enables signal transmission with other modules, and the real-time phase calibration unit corrects the phase shift of the magnetic field signal.

5. The non-contact motor position sensing system according to claim 4, characterized in that, The computational function of the digital signal processing unit is realized through the magnetic flux cooperative compensation formula, which is as follows: ； in, The compensated three-dimensional composite magnetic flux has the dimension of Weber (Wb). The original three-dimensional synthetic magnetic flux acquired by the magnetic signal acquisition module is expressed in Weber (Wb). This is the temperature influence coefficient, with dimensions 1 / ℃; The ambient temperature is currently being measured, with the dimension ℃. Standard ambient temperature, in °C; , is the external magnetic field interference influence coefficient, with dimensions of 1 / Tesla (1 / T). The current external magnetic field strength is expressed in Tesla (T). The standard external magnetic field strength is expressed in Tesla (T). is the historical signal attenuation weighting coefficient, with a dimension of 1; The serial number of the historical signal sampling point participating in the compensation, with a dimension of 1; For the first The original three-dimensional composite magnetic flux collected at all times is in Weber (Wb). The current sampling time is expressed in seconds (s). For the first The sampling time is measured in seconds (s). Let be the signal decay time constant, with the dimension of seconds (s).

6. The non-contact motor position sensing system according to claim 5, characterized in that, The digital signal processing unit performs position coordinate transformation based on the compensated magnetic flux using a three-dimensional position coordinate transformation formula. During the transformation, calibration data from the real-time phase calibration unit is simultaneously invoked. The three-dimensional position coordinate transformation formula is as follows: ; ； ； in, , , These are the three-dimensional coordinates of the motor position, in millimeters (mm). , , These are the installation reference angles for the three magnetic field detection units, with the dimension being degrees (°). , , These are the installation offset angles of the magnetic signal acquisition module relative to the motor stator, in degrees (°). , , These are the magnetic flux position transformation coefficients for the three coordinate axes, with dimensions in Weber / mm (Wb / mm). , , These are the coordinate correction coefficients for the three coordinate axes, with dimensions of 1 / Weber (1 / Wb). This is the sequence number of magnetic flux sampling accumulation times during coordinate transformation, with a dimension of 1; For the first The three-dimensional composite magnetic flux after compensation from the subsample is in the dimension of Weber (Wb).

7. The non-contact motor position sensing system according to claim 6, characterized in that, The voltage conversion unit achieves signal output through a voltage signal calibration formula, which is: ； in, The calibrated voltage signal output by the voltage conversion unit is in the volt (V) dimension. is the overall voltage conversion factor, with dimensions in volts per millimeter (V / mm). , , These are the voltage allocation weighting coefficients corresponding to the three-dimensional position coordinates, with a dimension of 1; The input supply voltage for the voltage conversion unit, in units of volts (V). The standard input supply voltage for the voltage conversion unit, in volts (V). This is the input voltage fluctuation correction factor, with dimensions of 1 / volt (1 / V). This is the inherent zero-point offset voltage of the voltage conversion unit, with dimensions in volts (V).

8. The non-contact motor position sensing system according to claim 1, characterized in that, The collaborative control module also includes a status monitoring subunit, a communication interface subunit, and a fault self-diagnosis subunit. The status monitoring subunit collects the operating parameters of each module, the communication interface subunit supports multi-protocol adaptive switching and realizes signal transmission with external terminals, and the fault self-diagnosis subunit detects the operating status of each module in real time and generates fault codes.

9. A method for processing and controlling a motor position non-contact sensing signal, applied to the motor position non-contact sensing system according to any one of claims 1-8, characterized in that, Includes the following steps: S1. System initialization: The collaborative control module configures the parameters of each module, sets the standard environmental parameters, outputs a synchronous clock signal, and each module enters standby mode; S2. Magnetic signal acquisition: The three-dimensional magnet assembly rotates with the rotor, and the magnetic signal acquisition module acquires the three-dimensional magnetic field signal, which is then conditioned and isolated before being transmitted to the digital signal processing unit. S3. Signal processing: After the digital signal processing unit reduces the noise of the signal, the real-time phase calibration unit corrects the signal phase shift, and then calculates the compensation magnetic flux through the magnetic flux cooperative compensation formula, and generates the three-dimensional coordinate value of the motor through the three-dimensional position coordinate transformation formula. S4. Voltage Conversion Output: The voltage conversion unit converts the coordinate values ​​into voltage signals using a voltage signal calibration formula. The control module monitors the signal stability and transmits the voltage signals to the motor control terminal through the communication interface subunit.

10. The non-contact sensing signal processing and control method for motor position according to claim 9, characterized in that, In S3, the validity of the original magnetic field signal is judged and abnormal signals are eliminated. The sampling time and magnetic field strength parameters of the abnormal signals are marked. In S4, the collaborative control module dynamically adjusts the sampling frequency according to the motor speed. When the speed increases, the sampling frequency is increased, and when the speed decreases, the sampling frequency is decreased.

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