A control method and motor drive system based on bilinear Hall effect

Abstract

This invention discloses a control method and motor drive system based on bilinear Hall sensors, relating to the field of motor control technology. It acquires two non-orthogonal voltage signals by arranging first and second linear Hall sensors with a mechanical angle of 45° on the stator side of the motor. An orthogonal reconstruction model is established using the initial 45° electrical angle difference. An equivalent orthogonal differential signal is reconstructed through non-orthogonal basis projection decoupling to adaptively cancel common-mode magnetic field interference. Subsequently, the differential signal undergoes arctangent calculation and global quadrant correction to obtain continuous actual mechanical angles, which are then converted into electrical angle inputs to the FOC control loop. Simultaneously, when the real-time speed falls into the low-speed threshold range, a dynamic feedforward compensation current is injected into the q-axis current command. This invention eliminates the need for expensive high-precision physical position encoders, completely eliminates the position detection blind zone of conventional Hall sensors, and effectively compensates for torque collapse in extremely low-speed motor conditions, achieving high-precision, high-torque constant force output across the entire range under a low-cost architecture.

Description

Technical Field

[0001] This invention relates to the field of motor drive and control technology, and more specifically, to a control method and motor drive system based on bilinear Hall effect. Background Technology

[0002] Efficient field-oriented control (FOC) of permanent magnet synchronous motors (PMSMs) heavily relies on precise feedback of the rotor's absolute position. Currently, the industry primarily employs three methods for acquiring rotor position signals, but all suffer from significant engineering limitations: First, high-precision physical sensors such as photoelectric encoders or rotary transformers are used. Although this solution can provide extremely high angular resolution, the hardware cost is high, it occupies a large axial volume of the motor, and it is prone to failure in harsh industrial environments such as dust, oil, and vibration, resulting in poor system reliability.

[0003] Secondly, a traditional three-phase Hall effect sensor is used. This solution is inexpensive, but its output resolution is only 60° electrical angle, which cannot meet the requirements of continuous coordinate transformation in FOC. Especially under conditions of extremely low motor speed operation or stall, it is very easy to cause severe "low-speed torque collapse" and commutation jitter.

[0004] Finally, a conventional analog linear Hall sensor was used to directly fit the angle measurement. However, this approach relies too heavily on the absolute amplitude of the air gap magnetic flux density, making it unable to overcome rotor demagnetization caused by motor operating temperature rise and common-mode electromagnetic interference generated by large stator current. Furthermore, the conventional arrangement is susceptible to spatial magnetic field harmonics at the magnetic pole junction, resulting in blind spots in position detection and abrupt changes in angle distortion.

[0005] In summary, existing motor position detection technologies consistently struggle to balance "extremely low hardware cost" with "continuous, high-precision, and highly disturbance-resistant control across the entire domain." Therefore, a novel, low-cost position sensing architecture and angle calculation algorithm are urgently needed in this field. Summary of the Invention

[0006] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0007] (a) The purpose of this invention; To address the shortcomings of existing motor position detection technologies, such as the high cost and poor environmental adaptability of high-precision physical sensors (e.g., photoelectric encoders, rotary transformers), and the low resolution, large magnetic pole blind zone, susceptibility to common-mode interference, and low-speed torque collapse of conventional Hall effect sensors, this invention aims to provide a low-speed, high-torque FOC motor drive system and control method based on bilinear Hall effect sensors. This invention achieves continuous high-precision position decoding across the entire motor range at extremely low hardware costs through deep integration of a sensor spatial hardware layout at a specific angle and a non-orthogonal basis projection decoupling algorithm. Furthermore, this decoding capability enables torque feedforward compensation under extremely low-speed conditions, thereby ensuring stable and constant force output of the motor across the entire speed range.

[0008] (ii) Technical solution; A control method based on bilinear Hall effect sensors, applied to an FOC motor drive system, includes the following steps: acquiring a first voltage signal and a second voltage signal output by a first linear Hall sensor and a second linear Hall sensor; There is a mechanical angle between the first linear Hall sensor and the second linear Hall sensor at their mounting positions on the stator side, which results in a non-orthogonal initial electrical angle difference between the first voltage signal and the second voltage signal. Based on the preset orthogonal reconstruction model, the first voltage signal and the second voltage signal are decoupled by non-orthogonal basis projection using the initial electrical angle difference, and two equivalent orthogonal differential signals are reconstructed. The decoupling process is used to eliminate common-mode magnetic field interference between the two signals. The arctangent operation is performed based on the ratio of the two equivalent orthogonal differential signals, and the quadrant correction is performed in combination with the polarity combination of the two original voltage signals to obtain the actual mechanical angle of the rotor. The actual mechanical angle is converted into an electrical angle and input to the FOC control loop for coordinate transformation and decoupling to obtain the d / q axis current. The real-time speed of the motor is monitored. When the real-time speed is within a preset low speed threshold range, a feedforward compensation current that is dynamically mapped to the real-time speed is injected into the q-axis current command of the FOC according to a preset compensation strategy. After modulation, a drive signal is output to control the motor.

[0009] Preferably, the orthogonal reconstruction model specifically includes: assuming the first voltage signal is... The second voltage signal is The initial electrical angle difference is ; The first voltage signal is directly used as the first equivalent quadrature signal. ,Right now ; Using spatial vector projection relationships, the components of the second voltage signal orthogonal to the first voltage signal are extracted as the second equivalent orthogonal signal. The calculation formula is: The and As the equivalent orthogonal two differential signals.

[0010] Preferably, the mechanical included angle is 45°, and the number of pole pairs of the motor is [number missing]. ; The initial electrical angle difference ; Among them, the pole pair number Conditions met: ,in It is a positive integer to avoid the first voltage signal and the second voltage signal being out of phase and collinear in electrical angle.

[0011] Preferably, the step of global quadrant correction specifically involves: detecting the positive and negative polarity states of the first and second voltage signals, and constructing a quadrant index; when the local angle output by the arctangent operation is located in the first or fourth quadrant, and the actual rotor position is determined to cross a polarity reversal point based on the quadrant index, the corresponding angle is added to or subtracted from the local angle. or A constant term, to obtain a continuous term. Actual mechanical perspective across the entire domain.

[0012] Preferably, after acquiring the two voltage signals and before performing orthogonal reconstruction, a signal preprocessing step is further included: performing hardware low-pass filtering and digital moving average filtering sequentially on the original signals output by the first linear Hall sensor and the second linear Hall sensor to remove high-frequency carrier subharmonics caused by the inverter PWM switch, and extracting the fundamental wave sample value as the first voltage signal and the second voltage signal.

[0013] Preferably, in the step of injecting feedforward compensation current, the compensation strategy specifically includes: setting a low-speed threshold. When the real-time mechanical speed At this time, low-speed compensation is activated; Calculate the feedforward compensation current for friction force The The amplitude reaches its maximum static friction compensation value at zero speed, and increases with the real-time mechanical rotation speed. The increase in exhibits a non-linear decay or a linear decrease. The This current is superimposed on the q-axis reference current output from the speed loop PID controller.

[0014] This application also discloses a motor drive system based on bilinear Hall effect sensors, comprising: a motor body including a stator core and a rotor permanent magnet; a bilinear Hall effect sensor assembly including a first linear Hall effect sensor and a second linear Hall effect sensor, which are arranged at a preset mechanical angle on the stator core side for acquiring two analog voltage signals reflecting changes in the magnetic field of the rotor permanent magnet; and a controller electrically connected to the bilinear Hall effect sensor assembly and the motor body, wherein the controller is configured to receive the two analog voltage signals and execute the control method described above.

[0015] Preferably, the bilinear Hall sensor assembly is the only sensing element for acquiring the rotor position signal, and there is no mechanical rotary transformer or photoelectric encoder in the system.

[0016] (iii) Beneficial effects; Compared with the prior art, the present invention has the following significant advantages: Breakthrough reduction in hardware cost and system size: This invention relies solely on two ordinary linear Hall sensors. Through a specific mechanical angle arrangement and a hardware-software co-design involving underlying algorithm reconstruction, it completely replaces traditional high-cost photoelectric encoders or mechanical rotary transformers. While ensuring high-frequency dynamic response and high-precision positioning, it reduces the hardware cost of the position sensing unit of the motor drive system by more than 70%, significantly shrinks the axial dimension of the motor, and improves the system's reliability under harsh conditions such as vibration and dust.

[0017] Eliminating position blind spots and achieving continuous tracking across the entire range: This invention employs a non-orthogonal mechanical angle (preferably 45°) layout, ensuring that the sampling windows of the two Hall signals perfectly complement each other in the spatial magnetic field. Compared to conventional arrangements, this invention can completely cover a single cycle of the alternating electromagnetic field of the motor, eliminating the single-sided magnetic field harmonic blind spot interference that is easily generated at the magnetic pole junction by a single sensor from a physical structure perspective, thus achieving seamless, continuous, and smooth rotor absolute position tracking.

[0018] Extremely strong resistance to common-mode magnetic field interference: The orthogonal reconstruction model and arctangent ratio calculation logic of this invention do not depend on the absolute amplitude of the air gap magnetic flux density. When the motor demagnetizes due to high load operation or when global electromagnetic disturbances are generated by large stator current, the common-mode variables of magnetic flux density amplitude caused by these factors are adaptively canceled in the differential ratio calculation. This enables the algorithm to output high-purity, low-jitter angle signals even in complex strong magnetic field interference environments.

[0019] This invention completely solves the torque collapse problem under extremely low-speed conditions: Traditional sensorless or low-resolution sensing solutions often suffer from FOC algorithm divergence and a severe drop in torque output when the motor is at extremely low speeds (e.g., close to 0 rpm) or during stall start-up due to inaccurate position observation. Based on continuous high-precision angle calculation results, this invention accurately calculates the mechanical speed in the extremely low-speed range in real time, and creatively introduces a feedforward compensation mechanism in the q-axis current loop that dynamically maps to the speed. This mechanism can accurately fill the torque collapse region under low-speed, high static friction conditions, ensuring that the motor still has strong, constant power output and rapid load response capabilities under extremely low-speed and even zero-speed conditions. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the mounting cross-section of a bilinear Hall sensor provided in an embodiment of the present invention; Figure 2 This is a diagram of the overall control hardware topology of the motor drive system provided in an embodiment of the present invention. Figure 3 The main flowchart of the control method based on bilinear Hall provided in the embodiments of the present invention is shown below; Figure 4 This is an internal control block diagram of the orthogonalization reconstruction and angle calculation module provided in an embodiment of the present invention; Figure 5 The waveform diagrams of the two non-orthogonal original voltage signals and the comparison diagram of the angle waveforms before and after global quadrant correction are provided for embodiments of the present invention. Figure 6 An improved FOC control block diagram including low-speed feedforward compensation is provided for embodiments of the present invention.

[0022] 10-Stator core; 20-Rotor permanent magnet; 30-Dual linear Hall sensor assembly; 31-First linear Hall sensor; 32-Second linear Hall sensor; 40-Controller; 50-Three-phase inverter; 60-Motor body. - First voltage signal; -Second voltage signal; -Local angle; - Actual mechanical angle. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "center," "longitudinal," "lateral," "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0027] In field-oriented control (FOC) of permanent magnet synchronous motors (PMSMs), accurate rotor position acquisition is the cornerstone of the entire control system. Traditional solutions heavily rely on expensive photoelectric encoders or resolvers, or use low-resolution Hall effect switches, resulting in either high system costs or severe torque collapse at low speeds. To address these issues, this invention provides a low-speed, high-torque FOC motor drive system and control method based on bilinear Hall effect sensors.

[0028] I. Hardware Driver System Architecture Description; First refer to Figure 1 and Figure 2The physical hardware support of the system provided in the embodiments of the present invention will be described in detail.

[0029] like Figure 1 The diagram shows a cross-sectional view of the dual-linear Hall sensor of the present invention. The motor body 60 mainly includes a stator core 10 and a rotor permanent magnet 20. A dual-linear Hall sensor assembly 30 is arranged on the circumferential air gap side of the stator core 10, which includes a first linear Hall sensor 31 and a second linear Hall sensor 32. Both are directly opposite the air gap magnetic field of the rotor permanent magnet 20, and are used to sense the alternating radial or tangential magnetic flux density as the rotor rotates in real time.

[0030] The core structural feature is that the mechanical mounting angle between the first linear Hall sensor 31 and the second linear Hall sensor 32 is precisely set. (Within reasonable machining tolerances). This non-orthogonal... The mechanical angle arrangement breaks with tradition or The conventional approach to this setup. Its physical significance lies in the fact that the sampling windows of the two analog voltage signals form a perfect complement in space, which can cover a single complete cycle of the alternating electromagnetic field of the motor, and eliminate the interference of the single-sided magnetic field harmonic blind zone generated by a single sensor at the magnetic pole junction from a physical structure perspective.

[0031] Combination Figure 2 As can be seen from the overall hardware topology diagram of the motor drive system, this system greatly simplifies the hardware links. The bilinear Hall sensor component 30 outputs an analog voltage signal reflecting changes in the magnetic field in real time. and The signal is transmitted to the controller 40 (such as an MCU or DSP). The controller 40 internally executes the core angle calculation and compensation algorithm, and directly outputs the SVPWM drive signal to control the three-phase inverter 50, thereby adjusting the three-phase stator current fed into the motor body 60.

[0032] It is worth emphasizing that in this system, presentation The arranged bilinear Hall sensor assembly 30 is the sole sensing element for acquiring the rotor position signal; the system requires no additional mechanical rotary transformers or photoelectric encoders. This significantly reduces system hardware costs while ensuring extremely high control accuracy. II. Detailed Derivation of Control Method and Core Algorithm The following is combined Figure 3 Main flowchart and Figure 4 , Figure 5 The algorithm details are shown in the diagram, and the control method provided by the embodiments of the present invention is described step by step.

[0033] S10: Acquire two raw voltage signals with an initial electrical angle difference. The ADC module of controller 40 synchronously acquires the first voltage signal output by the first linear Hall sensor 31 and the second linear Hall sensor 32. Second voltage signal In actual industrial environments, the high-frequency switching action of the inverter's PWM generates strong electromagnetic interference. Therefore, this step first performs cascaded preprocessing on the original signal: first, it uses an RC hardware low-pass filter circuit to filter out high-frequency switching glitches, then sends the signal into the controller for digital moving average filtering to extract the fundamental frequency sample value reflecting the actual air gap magnetic flux density change. Because the mechanical angle between the two is... Let the number of pole pairs of the motor be... Therefore, there is a fixed initial electrical angle difference between the two signals. At this time and It manifests as a sinusoidal signal with a non-orthogonal phase difference (such as...) Figure 5 (As shown).

[0034] S20-S30: Non-orthogonal basis projection decoupling and differential signal reconstruction. This is one of the core innovations of the algorithm in this invention. Traditional Hall angle measurement often relies on absolute amplitude, which is highly susceptible to common-mode interference caused by motor temperature rise and demagnetization. This invention combines... Figure 4 The orthogonalized reconstruction model shown undergoes the following mathematical decoupling: assuming the actual electrical angle of the rotor is... The amplitude of the Hall signal corresponding to the air gap magnetic flux density is (Including magnetic flux density and sensor sensitivity coefficient), the two voltage signals can be modeled as follows: because It is non-orthogonal (not equal to) The conventional arctangent operation cannot be used directly. Based on the relationship between spatial vector projection and trigonometric function expansion: Will Substituting into the above equation, we get: In order to construct and Extracting fully orthogonal virtual signal components. The term defines the first equivalent orthogonal signal. And derive the second equivalent orthogonal signal. : Anti-interference mechanism explanation: In the above decoupling model, in order to avoid system divergence, the denominator must satisfy the following condition. That is, the number of extreme logarithms is required. ( (where the integer is positive), thus avoiding the two signals being out of phase and collinear in electrical angle. At this point, we obtain a perfect quadrature differential signal group. In subsequent calculations of the ratio At that time, amplitude variable The ratio is canceled out by adaptive division. This means that whether the permanent magnet is temporarily demagnetized due to high load heating of the motor, or the global common-mode magnetic field fluctuation is generated by the large stator current, it will not affect the final ratio result, thus achieving a very strong anti-common-mode interference capability.

[0035] S40: Arctangent operation and global quadrant correction (combined with...) Figure 5 Perform arctangent operation on the reconstructed orthogonal signals: like Figure 5 The local angle is calculated directly using the arctangent function, as shown by the midpoint line. Its range is restricted to a finite interval (e.g.) arrive (between), manifesting as a discontinuous sawtooth wave. To obtain continuous actual mechanical angles... The controller detects in real time. and The positive and negative polarity states are used to construct a spatial physical quadrant index (e.g., divided into four intervals: ++, +-, --, -+). When a local angle crosses the polarity reversal boundary, the algorithm... Based on this, the corresponding code logic is used to smoothly add or subtract elements. or The constant term is expanded using periodic splicing. For example... Figure 5 As shown by the solid line, the final output is continuous across quadrants, without distortion or jumps. Actual mechanical angle slope signal across the entire domain.

[0036] III. After obtaining high-precision continuous angles using the improved FOC dual closed-loop and low-speed feedforward compensation, it enters... Figure 6 The improved FOC control loop is shown. S50: Electrical angle conversion and FOC coordinate transformation. First, the actual mechanical angle is multiplied by the number of pole pairs. This is converted to the electrical angle required for FOC. Subsequently, the controller acquires the actual three-phase stator current. The Clarke transformation is used to reduce its dimension to a two-phase stationary coordinate system. : Next, strictly using the high-precision electrical angle calculated above... As a rotating reference, the excitation current is decoupled through the Park transformation. and torque current : S60-S80: Dynamic feedforward compensation control based on a low-speed triggering mechanism. Traditional FOC (Frequency Control Operator) is prone to starting difficulties or torque collapse at extremely low speeds (e.g., near 0 rpm) due to extremely small back EMF and the dominance of static friction. This invention introduces... Figure 6 The "Low-Speed ​​Feedforward Compensation Module" shown at the bottom performs time differentiation operations on continuous actual mechanical angles within adjacent discrete sampling periods to calculate the actual mechanical speed. The controller has a low-speed threshold set internally. (For example When judging At this time, the system performs conventional closed-loop control, relying solely on the speed loop PID output. Axis commands. When judging When the low-speed condition is triggered (i.e., when the low-speed condition is met), the system activates the low-speed compensation strategy. At this time, the friction feedforward compensation module calculates the compensation current. The compensation current reaches its maximum static friction compensation value at zero speed stall, and increases with rotational speed. The rise is followed by a smooth decline. This... The feedforward is directly superimposed on the output of the speed loop PID controller. The reference current is used as the shaft reference current. Finally, after independent PID control of the current loop, the AC and DC shaft voltages are generated. After inverse Park transformation, the voltage command is restored to the stationary coordinate system. The command is finally sent to the SVPWM modulation module to generate a duty cycle waveform to control the three-phase inverter 60 to drive the motor.

[0037] In summary: The specific embodiments of the present invention are achieved through ingenious means. The deep integration of a bilinear Hall mechanical layout with a profound non-orthogonal basis decoupling algorithm not only completely avoids the high cost and vulnerability of high-precision physical encoders, but also effectively solves the common-mode interference and position blind zone problems existing in conventional Hall schemes. Furthermore, the low-speed feedforward compensation mechanism established based on high-precision continuous angle measurement capability completely fills the torque collapse region of the motor under extremely low-speed conditions, realizing constant high torque power output across the entire range, and has extremely high engineering application and commercial promotion value.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A control method based on bilinear Hall effect, applied to an FOC motor drive system, characterized in that, Includes the following steps: Acquire the first voltage signal and the second voltage signal output by the first linear Hall sensor and the second linear Hall sensor; There is a mechanical angle between the first linear Hall sensor and the second linear Hall sensor at their mounting positions on the stator side, which results in a non-orthogonal initial electrical angle difference between the first voltage signal and the second voltage signal. Based on the preset orthogonal reconstruction model, the first voltage signal and the second voltage signal are decoupled by non-orthogonal basis projection using the initial electrical angle difference, and two equivalent orthogonal differential signals are reconstructed. The decoupling process is used to eliminate common-mode magnetic field interference between the two signals. The arctangent operation is performed based on the ratio of the two equivalent orthogonal differential signals, and the quadrant correction is performed in combination with the polarity combination of the two original voltage signals to obtain the actual mechanical angle of the rotor. The actual mechanical angle is converted into an electrical angle and input to the FOC control loop for coordinate transformation and decoupling to obtain the d / q axis current. The real-time speed of the motor is monitored. When the real-time speed is within a preset low speed threshold range, a feedforward compensation current that is dynamically mapped to the real-time speed is injected into the q-axis current command of the FOC according to a preset compensation strategy. After modulation, a drive signal is output to control the motor.

2. The control method according to claim 1, characterized in that, The orthogonal reconstruction model specifically includes: assuming the first voltage signal is... The second voltage signal is The initial electrical angle difference is ; The first voltage signal is directly used as the first equivalent quadrature signal. ,Right now ; Using spatial vector projection relationships, the components of the second voltage signal orthogonal to the first voltage signal are extracted as the second equivalent orthogonal signal. The calculation formula is: The and As the equivalent orthogonal two differential signals.

3. The control method according to claim 2, characterized in that, The mechanical included angle is specifically 45°, and the number of pole pairs of the motor is... ; The initial electrical angle difference ; Among them, the pole pair number Conditions met: ,in It is a positive integer to avoid the first voltage signal and the second voltage signal being out of phase and collinear in electrical angle.

4. The control method according to claim 1, characterized in that, The specific steps of the global quadrant correction are as follows: Detect the positive and negative polarity states of the first and second voltage signals, and construct a quadrant index; when the local angle output by the arctangent operation is located in the first or fourth quadrant, and the actual rotor position crosses a polarity reversal point based on the quadrant index, supplement or subtract the corresponding value from the local angle. or A constant term, to obtain a continuous term. Actual mechanical perspective across the entire domain.

5. The control method according to claim 1, characterized in that, After acquiring the two voltage signals and before performing orthogonal reconstruction, a signal preprocessing step is also included: hardware low-pass filtering and digital moving average filtering are sequentially performed on the original signals output by the first linear Hall sensor and the second linear Hall sensor to remove high-frequency carrier subharmonics caused by the inverter PWM switch, and the fundamental wave sample value is extracted as the first voltage signal and the second voltage signal.

6. The control method according to claim 1, characterized in that, In the step of injecting feedforward compensation current, the compensation strategy specifically includes: setting a low-speed threshold. When the real-time mechanical speed At this time, low-speed compensation is activated; Calculate the feedforward compensation current for friction force The The amplitude reaches its maximum static friction compensation value at zero speed, and increases with the real-time mechanical rotation speed. The increase in exhibits a non-linear decay or a linear decrease. The This current is superimposed on the q-axis reference current output from the speed loop PID controller.

7. A motor drive system based on bilinear Hall effect, characterized in that, include: The motor body includes a stator core and a rotor permanent magnet; a dual-linear Hall sensor assembly includes a first linear Hall sensor and a second linear Hall sensor, which are arranged at a preset mechanical angle on the stator core side for acquiring two analog voltage signals reflecting changes in the magnetic field of the rotor permanent magnet; and a controller electrically connected to the dual-linear Hall sensor assembly and the motor body, the controller being configured to receive the two analog voltage signals and execute the control method as described in any one of claims 1 to 6.

8. The motor drive system according to claim 7, characterized in that, The bilinear Hall sensor assembly is the only sensing element for acquiring the rotor position signal, and there are no mechanical rotary transformers or photoelectric encoders in the system.

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