Permanent magnet synchronous linear motor, control system and position resolving method of permanent magnet synchronous linear motor

Abstract

The invention provides a permanent magnet synchronous linear motor, a control system and a position resolving method thereof, and relates to the technical field of motor control. The method comprises the following steps of: firstly, equidistantly arranging at least two pairs of linear Hall sensors with an electrical angle difference of 90 degrees and overlapped detection intervals along a stator, and acquiring orthogonal voltage to calculate an instantaneous position angle; the sensor pairs are dynamically switched through peak judgment and spliced to obtain the full-stroke continuous absolute position, and the instant speed is obtained through difference; the position and the speed are respectively input into a position loop, a speed loop and a current loop, and vector closed-loop control is realized by driving an inverter through SVPWM, so that high-resolution position and speed feedback is provided in the whole stroke, and the dynamic response and positioning precision of the linear motor are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a permanent magnet synchronous linear motor, a control system and a position calculation method thereof. Background Art

[0002] Permanent magnet synchronous linear motors (PMSLMs) have been widely used in fields such as semiconductor handling, precision positioning platforms, and high-speed rail transportation due to their high thrust density, fast response, and direct drive. To achieve high-precision motion control, the industry usually deploys optical scales, magnetic scales, or inductive linear encoders on the stator or mover to obtain continuous position and speed information, and implements closed-loop drive in conjunction with current-speed-position three-loop vector control. For long primary structures with strokes ranging from hundreds of millimeters to tens of meters, the mainstream approach is to use optical encoders or magnetic grating sensors with sub-micron resolution. Although they can provide high-precision feedback, they are generally expensive, complex to install and level, and are sensitive to industrial environmental factors such as dust, oil mist, and temperature drift, which increases maintenance costs.

[0003] To reduce system costs and improve environmental adaptability, some manufacturers are experimenting with replacing high-end encoders with linear Hall arrays or programmable linear Hall ICs, improving resolution through digital signal processing. Simultaneously, with the increasing integration of FPGAs and DSPs, position resolution and high-speed commutation logic are increasingly being implemented through software reconfiguration, enabling the controller to simultaneously implement high-bandwidth current loops, motion planning, and multi-source signal fusion within a single SoC. Furthermore, to meet the demands of both long travel and high dynamic performance, multi-pair linear Hall segmented detection, redundant switching, and thermal-electrical coupling safety protection have become research hotspots for the next generation of PMSLM drive systems.

[0004] Traditional three-phase Hall switches only provide six-segment commutation signals, with resolution limited by the number of pole pairs, making them inadequate for precise positioning. While some approaches improve accuracy by applying CORDIC or inverse trigonometric functions to single-pair linear Hall quadrature signals, the output of a single pair of sensors in long primary structures still suffers from periodic distortion, resulting in position "gaps." Existing multi-pair Hall "segmented commutation" algorithms often trigger commutation using fixed thresholds or mechanical shutters. This can easily misjudge peak positions during high-speed motion or temperature drift, leading to position angle jumps and velocity jitter. Furthermore, they lack online compensation mechanisms for the drop in magnetic flux density and Hall gain variations caused by stator temperature rise, making it difficult to achieve high-reliability closed-loop control over the entire travel and lifecycle. To address these issues, a technical solution is urgently needed that can achieve gapless, continuous, high-resolution position-velocity detection and vector drive across the entire stator travel while ensuring cost and environmental robustness. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a permanent magnet synchronous linear motor, a control system and a position solution method thereof, which can provide continuous high-precision position and speed feedback throughout the entire stroke, and significantly improve the dynamic performance and control accuracy of the permanent magnet synchronous linear motor through three-loop vector control.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A permanent magnet synchronous linear motor consists of a long primary stator arranged along a moving direction and a short secondary mover equipped with permanent magnets.

[0008] A closed-loop control system for the permanent magnet synchronous linear motor as described above comprises:

[0009] A Hall sensor array module is configured to provide at least two pairs of linear Hall sensors on the stator at a predetermined interval; each pair of linear Hall sensors differs by 90° in electrical angle, and the detection intervals of two adjacent pairs of linear Hall sensors partially overlap;

[0010] a position calculation module, configured to collect two orthogonal voltage signals output by each pair of the linear Hall sensors when the mover moves along the stator, and calculate corresponding instantaneous position angles based on the orthogonal voltage signals;

[0011] a sensor pair switching and position splicing module, configured to determine a currently valid linear Hall sensor pair by identifying a peak feature in the instantaneous position angle, and splice the local position angles of the currently valid linear Hall sensor pair into a continuous absolute position spanning the entire length of the stator;

[0012] A speed calculation module, configured to perform differential processing on the continuous absolute positions to obtain the instantaneous speed of the mover;

[0013] The three-loop vector control module is used to input the continuous absolute position and the instantaneous speed into the position loop, the speed loop and the current loop respectively, generate a three-phase inverter drive instruction, and implement vector closed-loop control of the permanent magnet synchronous linear motor.

[0014] A method for solving the closed-loop control system of the permanent magnet synchronous linear motor as described above is characterized by comprising:

[0015] At least two pairs of linear Hall sensors are arranged on the stator at a predetermined interval; the electrical angles of each pair of linear Hall sensors differ by 90 degrees, and the detection intervals of two adjacent pairs of linear Hall sensors partially overlap;

[0016] When the mover moves along the stator, two orthogonal voltage signals output by each pair of linear Hall sensors are collected, and corresponding instantaneous position angles are calculated based on the orthogonal voltage signals;

[0017] Determining a currently valid linear Hall sensor pair by identifying a peak feature in the instantaneous position angle, and splicing the local position angles of the currently valid linear Hall sensor pair into a continuous absolute position spanning the entire length of the stator;

[0018] Performing differential processing on the continuous absolute positions to obtain the instantaneous speed of the mover;

[0019] The continuous absolute position and the instantaneous speed are input into a position loop, a speed loop and a current loop respectively to generate a three-phase inverter drive instruction so as to implement vector closed-loop control on the permanent magnet synchronous linear motor.

[0020] Preferably, it also includes:

[0021] Monitoring the relative coordinates of the continuous absolute position in a detection interval of a currently valid linear Hall sensor pair;

[0022] When the relative coordinates cross a switching boundary set at the junction of the current detection interval and the detection interval of the next linear Hall sensor pair, the current valid linear Hall sensor pair is switched to the next linear Hall sensor pair, and the position splicing operation is continued.

[0023] Preferably, when the mover moves along the stator, two orthogonal voltage signals output by each pair of linear Hall sensors are collected, and corresponding instantaneous position angles are calculated based on the orthogonal voltage signals, including:

[0024] Simultaneously collecting the first voltage signal and the second voltage signal output by each pair of the linear Hall sensors using a unified sampling clock, and converting the first voltage signal and the second voltage signal into digital quantities;

[0025] Performing zero-bias compensation and amplitude normalization processing on the digital quantity to obtain the orthogonal voltage signal with consistent amplitude and orthogonal phase;

[0026] A two-parameter inverse tangent function is called to perform real-time calculation on the orthogonal voltage signal to obtain the instantaneous position angle corresponding to each pair of the linear Hall sensors.

[0027] Preferably, by identifying the peak feature in the instantaneous position angle, determining the currently valid linear Hall sensor pair, and splicing the local position angles of the currently valid linear Hall sensor pair into a continuous absolute position spanning the entire length of the stator, comprising:

[0028] Continuously sampling each pair of instantaneous position angles, and detecting the spike feature using a sign flip and amplitude threshold joint discrimination algorithm; the spike feature is a positive spike or a negative spike signal;

[0029] When the peak feature is detected, the positive peak or negative peak signal is compared with the number of movable pole pairs to determine the currently valid linear Hall sensor pair corresponding to the current instantaneous position angle;

[0030] If the detected peak feature indicates that the mover has entered the detection range of an adjacent linear Hall sensor pair, the index of the currently valid linear Hall sensor pair is automatically updated from the nth pair to the n+1th pair;

[0031] Reset the updated instantaneous position angle of the currently valid linear Hall sensor pair to zero, so that the local angle starting point is seamlessly connected with the end angle of the previous linear Hall sensor pair;

[0032] Based on the updated number of the currently valid linear Hall sensor pair and the corresponding starting point of the detection interval, the local position angle output by the updated currently valid linear Hall sensor pair is spliced ​​with the starting physical position of the covered interval to generate the continuous absolute position spanning the entire length of the stator.

[0033] Preferably, performing differential processing on the continuous absolute positions to obtain the instantaneous speed of the mover includes:

[0034] Acquiring the current value and the previous moment value of the continuous absolute position at a fixed sampling period;

[0035] Performing a first-order difference between the current value and the previous moment value to calculate the displacement change within the fixed sampling period;

[0036] Dividing the displacement change by the sampling period to obtain the instantaneous speed of the mover;

[0037] A filtering and smoothing process is performed on the instantaneous speed to reduce instantaneous fluctuations caused by signal quantization or switching boundary disturbances.

[0038] Preferably, the continuous absolute position and the instantaneous speed are input into a position loop, a speed loop, and a current loop respectively to generate a three-phase inverter drive instruction to implement vector closed-loop control of the permanent magnet synchronous linear motor, including:

[0039] Comparing the continuous absolute position with a preset target position to obtain a position error signal;

[0040] Input the position error signal into the position loop controller, and output the target speed as the given value of the speed loop;

[0041] Comparing the instantaneous speed with the target speed to obtain a speed error signal;

[0042] Inputting the speed error signal into a speed loop controller to output a current given value, including a direct-axis current given value and a quadrature-axis current given value;

[0043] Compare the current given value with the motor feedback current, input it to the current loop controller, and output voltage instructions for the q-axis and d-axis;

[0044] The voltage command is subjected to inverse Park transformation and space vector pulse width modulation processing to generate a driving command for the three-phase inverter.

[0045] Preferably, when the relative coordinate crosses a switching boundary set at the intersection of the current detection interval and the detection interval of the next linear Hall sensor pair, the currently valid linear Hall sensor pair is switched to the next linear Hall sensor pair, and the position stitching operation is continued, including:

[0046] Presetting a center position for the detection interval of each pair of linear Hall sensors, and setting the median between the center points of two adjacent pairs of linear Hall sensors as the switching boundary;

[0047] Align the current continuous absolute position with the starting point of the detection interval of the currently valid linear Hall sensor pair to obtain the relative coordinates within the current detection interval;

[0048] Comparing the relative coordinates with the corresponding switching boundary to determine whether the current detection interval and the adjacent detection interval have been crossed;

[0049] If it is judged to be out of bounds, it is determined that the mover has entered the detection range of the adjacent linear Hall sensor pair;

[0050] The currently valid linear Hall sensor pair is switched to an adjacent linear Hall sensor pair, and the local angle solution and continuous position stitching operations are continued based on the updated sensor pair.

[0051] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0052] The present invention utilizes multiple pairs of linear Hall sensors with orthogonal phases to construct overlapping detection intervals, and generates continuous absolute position in real time within the entire stator range through a "spike-switching-splicing" mechanism. The instantaneous speed is then obtained by differentiation, and a closed-loop control is formed with the position-speed-current three-loop. This enables the motor to obtain gap-free, high-resolution position feedback and dynamic speed information throughout the entire stroke, and then achieves thrust linearization and rapid response through vector control, significantly improving the positioning accuracy, speed stability and overall operating efficiency of the linear motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 A flow chart of a method provided by an embodiment of the present invention;

[0055] Figure 2 Schematic diagram of a short-secondary and long-primary permanent magnet linear synchronous motor provided by an embodiment of the present invention;

[0056] Figure 3 A structural analysis diagram provided for an embodiment of the present invention;

[0057] Figure 4 A schematic diagram of the installation position of a linear Hall effect sensor according to an embodiment of the present invention;

[0058] Figure 5 A schematic diagram of a Hall effect waveform provided by an embodiment of the present invention;

[0059] Figure 6 A schematic diagram of a waveform for calculating a position provided by an embodiment of the present invention;

[0060] Figure 7 A schematic diagram of the installation positions of multiple pairs of Hall Effect Hall sensors provided in an embodiment of the present invention;

[0061] Figure 8 A schematic diagram of waveforms at the switching position when the mover moves in the forward direction according to an embodiment of the present invention;

[0062] Figure 9 A schematic diagram of waveforms at the switching position when the mover moves in the reverse direction according to an embodiment of the present invention;

[0063] Figure 10 A schematic diagram of the switching position determination logic provided by an embodiment of the present invention;

[0064] Figure 11 A schematic diagram of the Arctanx position waveform during forward motion provided by an embodiment of the present invention;

[0065] Figure 12 A schematic diagram of the Arctanx position waveform during reverse motion provided by an embodiment of the present invention;

[0066] Figure 13 This is a three-ring control block diagram provided by an embodiment of the present invention.

[0067] Description of reference numerals:

[0068] 1. Stator; 2. Stator track; 3. Track groove; 4. Stator coil; 5. Hall plate; 6. Fiber optic sensor; 7. Stator core; 8. Coil; 9. Hall sensor; 10. Mover carriage; 11. Frame; 12. Permanent magnet; 13. Barcode plate; 14. Barcode; 15. Bottom mounting plate; 16. Stator cover; 17. Fiber optic reserved hole. DETAILED DESCRIPTION

[0069] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0070] The purpose of the present invention is to provide a permanent magnet synchronous linear motor, a control system and a position solution method thereof, which can provide continuous high-precision position and speed feedback throughout the entire stroke, and significantly improve the dynamic performance and control accuracy of the permanent magnet synchronous linear motor through three-loop vector control.

[0071] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0072] Figure 1 A flow chart of the method provided in the embodiment of the present invention is shown in FIG. Figure 1 As shown, the present invention provides a method for solving a closed-loop control system of a permanent magnet synchronous linear motor. The permanent magnet synchronous linear motor is composed of a long primary stator arranged along the motion direction and a short secondary mover equipped with a permanent magnet, including:

[0073] Step 100: Arrange at least two pairs of linear Hall sensors on the stator at a predetermined interval; each pair of linear Hall sensors differs by 90° in electrical angle, and the detection intervals of two adjacent pairs of linear Hall sensors partially overlap;

[0074] Step 200: When the mover moves along the stator, two orthogonal voltage signals output by each pair of linear Hall sensors are collected, and corresponding instantaneous position angles are calculated based on the orthogonal voltage signals;

[0075] Step 300: Determine the currently valid linear Hall sensor pair by identifying the peak feature in the instantaneous position angle, and splice the local position angles of the currently valid linear Hall sensor pair into a continuous absolute position spanning the entire length of the stator;

[0076] Step 400: performing differential processing on the continuous absolute positions to obtain the instantaneous velocity of the mover;

[0077] Step 500: Input the continuous absolute position and instantaneous speed into the position loop, speed loop and current loop respectively to generate a three-phase inverter drive instruction to implement vector closed-loop control of the permanent magnet synchronous linear motor.

[0078] like Figure 2 and Figure 3 As shown, the stator 1 of this embodiment consists of a stator track 2 extending in the direction of motion, with track grooves 3 machined through it on both sides. Several sets of stator coils 4, along with their stator cores 7, are embedded in the track grooves 3, with the coil turns parallel to the long axis of the track. A strip-shaped Hall effect plate 5 is fixed between the sidewalls of the coils 4 and the track grooves 3, with its length oriented in the same direction as the stator track 2. Several Hall effect sensors 9 are equidistantly packaged within the Hall effect plate 5, with the center-to-center distance between adjacent sensors meeting the requirement for an orthogonal arrangement of 90° electrical angle.

[0079] Multiple mounting channels are reserved between the Hall plate 5 and the bottom of the groove for the installation of distributed fiber optic sensors 6. Fiber optic cables are routed through fiber-reserved holes 17 and sealed by a stator cover 16, forming an integrated temperature rise and vibration monitoring channel. A barcode plate 13 is mounted above the stator track 2. Etched with a continuous barcode 14, it facilitates redundant positioning using an external visual or laser encoder. The entire stator assembly is secured to the base via a bottom mounting plate 15.

[0080] The mover carriage 10 consists of a lightweight frame 11 and embedded permanent magnets 12. The bottom surface of the frame 11 forms a rolling or air-floating bearing with the upper surface of the stator track 2, allowing magnetic coupling between the permanent magnets 12 and the stator coils 4 within the air gap to achieve thrust output. A barcode plate 13 is positioned opposite the frame 11, and an optional 2D reader can be added to achieve dual-channel position redundancy.

[0081] The Hall sensors are mounted on the stator, with two Hall sensors arranged 90° apart in electrical angle. This creates a 90° difference in the output signals of the two Hall sensors. As the mover passes by, the two Hall sensors output two orthogonal signals. These two orthogonal voltage signals can be used as the sine and cosine functions of the mover's position angle, and position information can be derived using a formula.

[0082] Among them, H s and H c is the voltage value induced by a single Hall sensor, A is the voltage amplitude induced by the Hall sensor, θ is the position, and a is the position coefficient (usually 1).

[0083] Hall installation position diagram as shown Figure 4 As shown, the Hall signal waveform and the position waveform after solution are as follows Figure 5 and Figure 6As shown in the case of 5 pairs of poles of the mover, in order to cover the position detection of the entire stator segment, multiple pairs of linear Hall sensors need to be installed, and the installation distance between each pair of Hall sensors must ensure that the Hall signals overlap to ensure that there is no place where the position cannot be detected. The installation positions of multiple pairs of Hall sensors are as follows: Figure 7 As shown. Taking four pairs of linear Hall sensors as an example, we can see that there are signal overlaps between pairs. If we want to achieve continuous position signals in the entire segment, we must necessarily involve linear Hall pair swapping. The position waveforms calculated for two adjacent pairs are shown as follows: Figure 8 and Figure 9 As shown. (The shadow is the position difference calculated by two pairs of linear Hall solutions)

[0084] Regarding pair switching, the present invention proposes the following logic (taking two pairs as an example): It can be seen that when the mover (5 pairs of poles) passes by, the position waveform solved by each pair of Hall has five peaks, with positive peaks in the forward direction and negative peaks in the reverse direction. The number of peaks can be used to determine which pair of Hall-resolved position signals to use.

[0085] Suppose the Hall pair number X, the mover pole pair number Y, and the peak number Z, we have the following relationship:

[0086] When X=1:

[0087] Z = Y;

[0088] When X is any value, when the Y polar mover passes through:

[0089] Z = XY;

[0090] Assuming θ is the position of the actuator, X1 and X2 are each Hall in the Hall pair, then the following formula is obtained:

[0091] Where θ is the position, x1 and x2 are the sensing values ​​of each Hall.

[0092] Finding θ by using the four-quadrant inverse tangent

[0093]

[0094] The exchange formula is:

[0095] θ=θ n , (n-1)z <Z<nz

[0096] Among them, θ is the final output position, θ n is the position resolved by the nth pair of Hall equations.

[0097] Judgment logic such as Figure 10 As shown (the number of pole pairs is Y):

[0098] Start (pole pair number is Y)

[0099] Determine whether Arctan(n) has a peak, and also determine whether Arctan(n+1) has a peak:

[0100] If Arctan(n) has a peak, then determine whether the peak is positive or negative:

[0101] If positive, execute nY+N++

[0102] If negative, execute nY+N--

[0103] Determine whether N is greater than Y:

[0104] If N is less than Y, let Arctanx = Arctan(n).

[0105] If N is greater than Y, let Arctanx = Arctan(n+1).

[0106] The switching logic is as above. Arctan1 is the position information solved by the first pair of Hall sensors. Similarly, Arctan2 is the position information solved by the second pair of Hall sensors. Arctanx is the final output position information. The final waveform is as follows: Figure 11 and Figure 12 As shown, it can be seen that the final position waveform is continuous and complete.

[0107] The three-loop control block diagram is as follows Figure 13 As shown in the figure, the position controller receives external input and obtains position feedback. The speed PI module receives the speed signal from the position controller and the feedback speed signal. The speed PI module outputs a quadrature-axis current command Iq and a direct-axis current command Id. The Iq current PI module adjusts based on Iq, Id, and the feedback Iq, Id, to output voltage commands Uq and Ud. An inverse Park transform is used to convert Uq and Ud into voltages (Uα) and (Uβ) in a two-phase stationary coordinate system. The three-phase motor currents Ia, Ib, and Ic are transformed using a Clark transform to obtain currents (Iα) and (Iβ) in a two-phase stationary coordinate system. These currents are then fed back to the Iq current PI module through a Park transform. (Uα) and (Uβ) are input to the SVPWM (space vector pulse width modulation) module, generating control signals to drive the three-phase full-bridge inverter circuit and power the PMLSM. Position detection is performed using linear Hall elements. After position resolution, the feedback position and velocity are sent back to the corresponding modules, forming a closed-loop control system.

[0108] (The feedback position is the output of the switching algorithm) This signal is used in the above Park transformation and inverse Park transformation as well as the speed PI controller and position PI controller.

[0109] Park transformation formula:

[0110]

[0111] Among them, θ is the Hall effect signal, and the following formula is also

[0112] Inverse Park transform formula:

[0113] U α =U d cosθ-U q sinθ

[0114] U β =U q cosθ+U d sinθ

[0115] Position PI formula:

[0116] θ Δ =θ set -θ

[0117]

[0118] The linear Hall sensor replaces the above position calculation module to complete the subsequent speed and position closed-loop control.

[0119] Among them, U α and U β They are the phase voltages in the two-phase stationary (αβ) coordinate system, U d and U q are the phase voltages in the two-phase rotating (dq) coordinate system, θ set is the position setting value, θ Δ is the position error, and out is the PI output.

[0120] Corresponding to the above method, this embodiment further provides a permanent magnet synchronous linear motor closed-loop control system based on a linear Hall sensor, comprising:

[0121] A Hall sensor array module is configured to provide at least two pairs of linear Hall sensors on the stator at a predetermined interval; each pair of linear Hall sensors differs by 90° in electrical angle, and the detection intervals of two adjacent pairs of linear Hall sensors partially overlap;

[0122] a position calculation module, configured to collect two orthogonal voltage signals output by each pair of the linear Hall sensors when the mover moves along the stator, and calculate corresponding instantaneous position angles based on the orthogonal voltage signals;

[0123] a sensor pair switching and position splicing module, configured to determine a currently valid linear Hall sensor pair by identifying a peak feature in the instantaneous position angle, and splice the local position angles of the currently valid linear Hall sensor pair into a continuous absolute position spanning the entire length of the stator;

[0124] A speed calculation module, configured to perform differential processing on the continuous absolute positions to obtain the instantaneous speed of the mover;

[0125] The three-loop vector control module is used to input the continuous absolute position and the instantaneous speed into the position loop, the speed loop and the current loop respectively, generate a three-phase inverter drive instruction, and implement vector closed-loop control of the permanent magnet synchronous linear motor.

[0126] This invention uses linear Hall sensors as position sensors in the control of a short-primary, long-secondary permanent magnet synchronous linear motor. This effectively reduces the cost of traditional position sensors and improves interference resistance. It also eliminates signal line limitations, greatly facilitating long-distance control of the permanent magnet synchronous motor.

[0127] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0128] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A permanent magnet synchronous linear motor, characterized in that: The permanent magnet synchronous linear motor consists of a long primary stator arranged along the motion direction and a short secondary mover equipped with permanent magnets.

2. A closed-loop control system for a permanent magnet synchronous linear motor according to claim 1, characterized in that: include: A Hall sensor array module, configured to arrange at least two pairs of linear Hall sensors on the stator at a predetermined interval; The electrical angles of each pair of linear Hall sensors differ by 90°, and the detection intervals of two adjacent pairs of linear Hall sensors partially overlap; a position calculation module, configured to collect two orthogonal voltage signals output by each pair of the linear Hall sensors when the mover moves along the stator, and calculate corresponding instantaneous position angles based on the orthogonal voltage signals; a sensor pair switching and position splicing module, configured to determine a currently valid linear Hall sensor pair by identifying a peak feature in the instantaneous position angle, and splice the local position angles of the currently valid linear Hall sensor pair into a continuous absolute position spanning the entire length of the stator; A speed calculation module, configured to perform differential processing on the continuous absolute positions to obtain the instantaneous speed of the mover; The three-loop vector control module is used to input the continuous absolute position and the instantaneous speed into the position loop, the speed loop and the current loop respectively, generate a three-phase inverter drive instruction, and implement vector closed-loop control of the permanent magnet synchronous linear motor.

3. A method for solving the closed-loop control system of a permanent magnet synchronous linear motor according to claim 2, characterized in that: include: At least two pairs of linear Hall sensors are arranged on the stator at a predetermined interval; the electrical angles of each pair of linear Hall sensors differ by 90 degrees, and the detection intervals of two adjacent pairs of linear Hall sensors partially overlap; When the mover moves along the stator, two orthogonal voltage signals output by each pair of linear Hall sensors are collected, and corresponding instantaneous position angles are calculated based on the orthogonal voltage signals; Determining a currently valid linear Hall sensor pair by identifying a peak feature in the instantaneous position angle, and splicing the local position angles of the currently valid linear Hall sensor pair into a continuous absolute position spanning the entire length of the stator; Performing differential processing on the continuous absolute positions to obtain the instantaneous speed of the mover; The continuous absolute position and the instantaneous speed are input into a position loop, a speed loop and a current loop respectively to generate a three-phase inverter drive instruction so as to implement vector closed-loop control on the permanent magnet synchronous linear motor.

4. The method for solving the closed-loop control system of a permanent magnet synchronous linear motor according to claim 3, characterized in that: Also includes: Monitoring the relative coordinates of the continuous absolute position in a detection interval of a currently valid linear Hall sensor pair; When the relative coordinates cross a switching boundary set at the junction of the current detection interval and the detection interval of the next linear Hall sensor pair, the current valid linear Hall sensor pair is switched to the next linear Hall sensor pair, and the position splicing operation is continued.

5. The method for solving the closed-loop control system of the permanent magnet synchronous linear motor according to claim 3, characterized in that: When the mover moves along the stator, two orthogonal voltage signals output by each pair of linear Hall sensors are collected, and corresponding instantaneous position angles are calculated based on the orthogonal voltage signals, including: Simultaneously collecting the first voltage signal and the second voltage signal output by each pair of the linear Hall sensors using a unified sampling clock, and converting the first voltage signal and the second voltage signal into digital quantities; Performing zero-bias compensation and amplitude normalization processing on the digital quantity to obtain the orthogonal voltage signal with consistent amplitude and orthogonal phase; A two-parameter inverse tangent function is called to perform real-time calculation on the orthogonal voltage signal to obtain the instantaneous position angle corresponding to each pair of the linear Hall sensors.

6. The method for solving the closed-loop control system of a permanent magnet synchronous linear motor according to claim 3, characterized in that: By identifying the peak feature in the instantaneous position angle, determining the currently valid linear Hall sensor pair, and splicing the local position angle of the currently valid linear Hall sensor pair into a continuous absolute position spanning the entire length of the stator, including: Continuously sampling each pair of instantaneous position angles, and detecting the spike feature using a sign flip and amplitude threshold joint discrimination algorithm; the spike feature is a positive spike or a negative spike signal; When the peak feature is detected, the positive peak or negative peak signal is compared with the number of movable pole pairs to determine the currently valid linear Hall sensor pair corresponding to the current instantaneous position angle; If the detected peak feature indicates that the mover has entered the detection range of an adjacent linear Hall sensor pair, the index of the currently valid linear Hall sensor pair is automatically updated from the nth pair to the n+1th pair; Reset the updated instantaneous position angle of the currently valid linear Hall sensor pair to zero, so that the local angle starting point is seamlessly connected with the end angle of the previous linear Hall sensor pair; Based on the updated number of the currently valid linear Hall sensor pair and the corresponding starting point of the detection interval, the local position angle output by the updated currently valid linear Hall sensor pair is spliced ​​with the starting physical position of the covered interval to generate the continuous absolute position spanning the entire length of the stator.

7. The method for solving the closed-loop control system of a permanent magnet synchronous linear motor according to claim 3, characterized in that: Performing differential processing on the continuous absolute positions to obtain the instantaneous speed of the mover includes: Acquiring the current value and the previous moment value of the continuous absolute position at a fixed sampling period; Performing a first-order difference between the current value and the previous moment value to calculate the displacement change within the fixed sampling period; Dividing the displacement change by the sampling period to obtain the instantaneous speed of the mover; A filtering and smoothing process is performed on the instantaneous speed to reduce instantaneous fluctuations caused by signal quantization or switching boundary disturbances.

8. The method for solving the closed-loop control system of a permanent magnet synchronous linear motor according to claim 3, characterized in that: Inputting the continuous absolute position and the instantaneous speed into a position loop, a speed loop, and a current loop respectively, generating a three-phase inverter drive instruction to implement vector closed-loop control on the permanent magnet synchronous linear motor, including: Comparing the continuous absolute position with a preset target position to obtain a position error signal; Input the position error signal into the position loop controller, and output the target speed as the given value of the speed loop; Comparing the instantaneous speed with the target speed to obtain a speed error signal; Inputting the speed error signal into a speed loop controller to output a current given value, including a direct-axis current given value and a quadrature-axis current given value; Compare the current given value with the motor feedback current, input it to the current loop controller, and output voltage instructions for the q-axis and d-axis; The voltage command is subjected to inverse Park transformation and space vector pulse width modulation processing to generate a driving command for the three-phase inverter.

9. The method for solving the closed-loop control system of a permanent magnet synchronous linear motor according to claim 4, characterized in that: When the relative coordinate crosses a switching boundary set at the intersection of the current detection interval and the detection interval of the next linear Hall sensor pair, the currently valid linear Hall sensor pair is switched to the next linear Hall sensor pair, and the position splicing operation is continued, including: Presetting a center position for the detection interval of each pair of linear Hall sensors, and setting the median between the center points of two adjacent pairs of linear Hall sensors as the switching boundary; Align the current continuous absolute position with the starting point of the detection interval of the currently valid linear Hall sensor pair to obtain the relative coordinates within the current detection interval; Comparing the relative coordinates with the corresponding switching boundary to determine whether the current detection interval and the adjacent detection interval have been crossed; If it is judged to be out of bounds, it is determined that the mover has entered the detection range of the adjacent linear Hall sensor pair; The currently valid linear Hall sensor pair is switched to an adjacent linear Hall sensor pair, and the local angle solution and continuous position stitching operations are continued based on the updated sensor pair.

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