Method and system for detecting initial phase of rotor, and device and readable storage medium

Abstract

Disclosed in the present invention are a method and apparatus for detecting an initial phase of a rotor, and a device and a readable storage medium. The method comprises: applying an excitation current at a fixed magnitude to a rotor at every other preset angle in a preset circumferential direction; on the basis of a displacement offset of the rotor, acquiring a coarse phase of an initial phase of the rotor; applying an excitation current at a fixed magnitude to the coarse phase at every preset time interval, updating the coarse phase of the initial phase of the rotor on the basis of the rotation direction of the rotor, and acquiring a first fine phase of the initial phase of the rotor; and rotating the first fine phase by 180 degrees to acquire a second fine phase, respectively applying excitation voltages at the same magnitude in the directions of the first fine phase and the second fine phase, and on the basis of the magnitude of the current amplitude in the first fine phase and the magnitude of the current amplitude in the second fine phase under the excitation voltages, acquiring the initial phase of the rotor. The method in the present invention is simple, involves a low calculation workload and has low implementation costs, and reduces the occupation of system resources; moreover, the method in the present invention does not affect the operation of servo electric motors, and thus has relatively good adaptability.

Description

Rotor initial phase detection method, system, device and readable storage medium

[0001] The present invention claims priority to Chinese patent application number 2024100457684, filed with the Patent Office of China on January 11, 2024, entitled “Method, system, device and readable storage medium for detecting rotor initial phase”. The entire contents of the application are incorporated herein by reference. Technical Field

[0002] The present invention relates to the field of motor control, and in particular to a rotor initial phase detection method, system, device and readable storage medium. Background Art

[0003] Currently, the main drive device in CNC machine tool control systems is the servo motor. In servo motor control, if the initial position of the rotor is not known, the rotor will reverse or lose step, resulting in startup failure. In hardware, an absolute encoder can be used to determine the initial position of the rotor, but this is expensive and bulky, and its application scenarios are limited. In actual application, the three-phase power connection between the driver and the motor may be reversed. In this case, the automatic phase algorithm used in the existing technology can find the initial phase angle, but because it uses a high-frequency current signal injection method, its demodulation algorithm is complex, the amount of calculation is relatively large, and it consumes a lot of system resources. At the same time, the motor will produce large jitter. For servo motors used in CNC machine tools, it is necessary to ensure that they do not have jitter to prevent it from affecting the workpiece or machine equipment.

[0004] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0005] Summary of the Invention

[0006] The object of the present invention is to provide an initial phase detection method, system, device and readable storage medium, which can obtain the initial position of the motor rotor at a low cost and with a relatively streamlined algorithm to prevent the rotor from reversing or losing step.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides a rotor initial phase detection method, which is applied to a servo motor control system and includes:

[0009] With the symmetric center of the rotor as the center of a circle, a fixed excitation current is applied to the rotor at intervals of a preset angle along a preset positive direction, wherein the positive direction is a counterclockwise direction or a clockwise direction; and a coarse phase of the initial phase of the rotor is obtained based on the displacement offset of the rotor;

[0010] At predetermined time intervals, a fixed excitation current is applied to the coarse phase, the coarse phase of the rotor initial phase is updated based on the rotor rotation direction, and a first fine phase of the rotor initial phase is obtained based on the updated coarse phase of the rotor initial phase;

[0011] The first fine phase is rotated 180 degrees to obtain a second fine phase, and excitation voltages of the same magnitude are applied in the directions of the first fine phase and the second fine phase respectively. The initial phase of the rotor is obtained based on the current amplitudes of the first fine phase and the second fine phase under the excitation voltage.

[0012] In one or more embodiments, obtaining a coarse phase of the initial phase of the rotor based on the displacement offset of the rotor includes:

[0013] Based on the positive direction, sequentially obtaining the displacement offset of the rotor;

[0014] If the displacement bias of the rotor in the positive direction reaches the maximum value first and the displacement bias of the rotor in the negative direction reaches the maximum value later, the coarse phase of the initial phase of the rotor is: θ1 = θ max +θ min -180°

[0015] If the displacement bias of the rotor in the negative direction reaches the maximum value first and the displacement bias of the rotor in the positive direction reaches the maximum value later, the coarse phase of the initial phase of the rotor is: θ1 = θ max +θ min

[0016] Wherein, θ1 is the coarse phase of the rotor initial phase, θ max is the phase angle corresponding to the maximum displacement offset of the rotor in the positive direction based on the excitation current, θ min is the phase angle corresponding to the minimum value of the displacement bias of the rotor along the negative direction based on the excitation current.

[0017] In one or more embodiments, the method further comprises:

[0018] If the excitation current does not cause the rotor to deflect at an angle, the angle is the first fine phase of the rotor initial phase.

[0019] In one or more embodiments, updating the coarse phase of the rotor initial phase based on the rotor rotation direction, and acquiring the first fine phase of the rotor initial phase based on the updated coarse phase of the rotor initial phase includes:

[0020] If the offset displacement of the rotor is along a first direction, the coarse phase is deflected by a preset adjustment angle in the opposite direction of the first direction, and the adjusted phase angle is used as the new coarse phase of the rotor initial phase, wherein the first direction is a preset positive direction or reverse direction;

[0021] The excitation current is applied to the new coarse phase, and the coarse phase is updated based on the bias displacement of the rotor until the excitation current is applied to the coarse phase so that the rotor bias displacement is in the opposite direction of the first direction. At this time, the coarse phase of the rotor initial position is the first fine phase of the rotor initial phase.

[0022] In one or more embodiments, the preset adjustment angle is no greater than 1°.

[0023] In one or more embodiments, obtaining the rotor initial phase based on current amplitudes of the first fine phase and the second fine phase under the excitation voltage includes:

[0024] If the current amplitude of the first fine phase is greater than the current amplitude of the second fine phase, the first fine phase is the initial phase of the rotor;

[0025] If the current amplitude of the first fine phase is smaller than the current amplitude of the second fine phase, the second fine phase is the initial phase of the rotor.

[0026] In one or more embodiments, the direction of the excitation current is consistent with the direction of the N pole of the servo motor.

[0027] In a second aspect, the present invention provides a rotor initial phase detection system, comprising:

[0028] a first sending module, configured to apply a fixed excitation current to the rotor at intervals of a preset angle along a preset positive direction with the symmetric center of the rotor as the center of a circle, wherein the positive direction is counterclockwise or clockwise;

[0029] A first acquisition module is configured to acquire a coarse phase of the initial phase of the rotor based on a displacement offset of the rotor;

[0030] a second sending module, configured to apply an excitation current of a fixed magnitude along the coarse phase direction at each preset time interval, update the coarse phase of the rotor initial phase based on the rotor rotation direction, and obtain a first fine phase of the rotor initial phase based on the updated coarse phase of the rotor initial phase;

[0031] The second acquisition module is used to rotate the first fine phase by 180 degrees to obtain a second fine phase, apply excitation voltages of the same magnitude in the directions of the first fine phase and the second fine phase, and obtain the rotor initial phase based on the current amplitudes of the first fine phase and the second fine phase under the excitation voltage.

[0032] In a third aspect, the present invention provides a computer device comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, computer instructions are stored in the memory, and the processor executes the rotor initial phase detection method by executing the computer instructions.

[0033] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the rotor initial phase detection method.

[0034] Compared with the prior art, the rotor initial phase detection method provided by the present invention detects the rotor initial phase based on a coarse and fine dual-granularity detection standard. This rotor initial phase detection method has the following advantages:

[0035] (1) The rotor initial phase detection method provided by the present invention is simple, greatly reduces the amount of calculation compared with the existing technology, reduces the occupation of system resources and has a low implementation cost.

[0036] (2) The rotor initial phase detection method provided by the present invention will not affect the operation of the servo motor and has stronger adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG1 is a schematic diagram of preset angles in one embodiment of the present invention;

[0038] FIG2 is a schematic diagram of a process for detecting the initial phase of a rotor according to an embodiment of the present invention;

[0039] FIG3 is a structural block diagram of a rotor initial phase detection system according to one embodiment of the present invention;

[0040] FIG4 is a block diagram of an electronic device according to an embodiment of the present invention;

[0041] FIG5 is a vector diagram of a servo motor in one embodiment of the present invention. DETAILED DESCRIPTION

[0042] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0043] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components.

[0044] In order to facilitate understanding of the technical solutions of this application, the technical terms that may appear in the present invention are first explained in detail below.

[0045] The Park transform is the most commonly used coordinate transformation for analyzing synchronous motor operation. It was proposed by American engineer R.H. Park in 1929. The Park transform projects the stator's three-phase currents (a, b, and c) onto the rotor's rotating direct axis (d-axis), quadrature axis (q-axis), and zero axis (0-axis) perpendicular to the d and q planes. This diagonalizes the stator inductance matrix and simplifies synchronous motor analysis. This transforms the a, b, c coordinate system into the d, q coordinate system.

[0046] Clark Transform: Decomposes (projects) the UVW three-phase current onto the stationary ab coordinate axes to obtain Ia and Ib. This method is called the Clark Transform (also called the phase transform). The transformation yields Ia and Ib, which can then be used to determine the d-axis and q-axis currents. Its significance lies in providing two parameters, Ia and Ib, for the Park Transform.

[0047] In the existing technical solutions, the main method for detecting the initial position of the servo motor is the high-frequency current signal injection method. The high-frequency current injection method is to inject a high-frequency current signal, extract the high-frequency response voltage and then identify the rotor position. However, there are still inevitable problems such as the performance is greatly affected by the current loop PI parameters, the demodulation algorithm is complex, the current injection causes motor vibration, and affects the workpiece or machine tool.

[0048] The inventors of the present invention discovered the main shortcomings of the existing technology and proposed a new technical implementation idea based on the shortcomings of the existing technology: applying excitation current to the rotor at different angles, obtaining the coarse phase of the initial position based on the rotor offset, and then applying excitation current to the rotor at the coarse phase, fine-tuning the coarse phase to obtain the fine phase corresponding to the initial position of the rotor, and then judging the NS polarity at the fine phase, thereby achieving the effect of accurately obtaining the initial position of the rotor.

[0049] Please refer to Figure 2, which is a schematic diagram of the process of detecting the initial phase of the rotor in one embodiment of the present invention. The method for detecting the initial phase of the rotor specifically includes the following steps:

[0050] S201: applying a fixed excitation current to the rotor at intervals of a preset angle along a preset positive direction with the symmetric center of the rotor as the center of a circle, wherein the positive direction is counterclockwise or clockwise;

[0051] It is understandable that the smaller the preset angle is, the more accurate the coarse phase obtained will be, but relatively, it will also occupy more system computing resources; the larger the preset angle is, the greater the error of the coarse phase obtained will be, so the value of the preset angle is preferably 30°.

[0052] It should be noted that, with the center of symmetry of the rotor as the center of the circle, an excitation current of a fixed magnitude is applied to the rotor at every preset angle along the preset positive direction. Only the angle of the rotor is set for one cycle and the excitation current is applied for detection. Angle values ​​exceeding one cycle are not considered to avoid repeated occurrence of the maximum value of the rotor bias in the positive direction and / or the maximum value of the rotor bias in the reverse direction.

[0053] It should also be noted that the direction of the excitation current is consistent with the direction of the N pole of the servo motor to be detected.

[0054] For example, Figure 1 shows a schematic diagram of the preset angles described in one embodiment of the present invention. In this embodiment, a 30° preset angle is used, generating 12 application positions for applying a fixed excitation current: 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300°, and 330°. According to the aforementioned spacing rule, angles greater than or equal to 360°, such as 360° and 390°, are not considered because they exceed one rotor revolution or have already been sampled repeatedly.

[0055] Furthermore, regarding the selection of the starting angle for applying the excitation current, the embodiment of the present invention does not impose any limitation on this.

[0056] S202: Acquire a coarse phase of the initial phase of the rotor based on the displacement offset of the rotor;

[0057] In an exemplary embodiment, obtaining the coarse phase of the rotor initial phase based on the rotor displacement offset includes: sequentially obtaining the rotor displacement offset based on the positive direction; if the rotor displacement offset in the positive direction reaches a maximum value first and the rotor displacement offset in the negative direction reaches a maximum value later, then the coarse phase of the rotor initial phase is: θ1=θ max +θ min-180°

[0058] If the displacement bias of the rotor in the negative direction reaches the maximum value first and the displacement bias of the rotor in the positive direction reaches the maximum value later, the coarse phase of the initial phase of the rotor is: θ1 = θ max +θ min

[0059] Wherein, θ1 is the coarse phase of the rotor initial phase, θ max is the phase angle corresponding to the maximum displacement offset of the rotor in the positive direction based on the excitation current, θ min is the phase angle corresponding to the minimum value of the displacement bias of the rotor along the negative direction based on the excitation current.

[0060] It should be noted that, as shown in Figure 5, it is a schematic diagram of the motor vector, where A, B, and C represent the axes of the three-phase stator windings, respectively, with a phase difference of 120° between each phase. The α and β axes of the stationary two-phase stator coordinate system are derived from the ABC coordinates through the Clark transformation, and the phase difference between the α and β axes is 90°; the coordinate d and q axes that rotate with the rotor are derived from the α and β axes through the Park transformation, and the phase difference is also 90°; this converts the three-phase alternating current in the stator winding into two-phase direct current through the Clark and Park transformation, that is, the torque current and the excitation current, wherein the excitation current is consistent with the direction of the motor's N pole; in the process of phase-finding the initial phase of the rotor, when the actual excitation current direction deviates from the N pole direction of the motor, a component will be generated in the direction of the torque current, and the component in this direction will cause the motor rotor to rotate, driving the motor to rotate.

[0061] For example, in one specific embodiment, following the conditions of the above embodiment, the magnetic pole direction is determined based on the positions where the offset reaches its maximum and minimum values ​​during overall motion, with the counterclockwise direction being the positive direction. The maximum offset occurs at position 5, and the minimum at position 11. Based on the above formula, the maximum value is taken first, followed by the minimum value. Substituting the data into the equation, we obtain 120° + 300° - 180° = 240°. This means that the angle of 240 degrees, or position 9, represents the coarse phase of the rotor's initial phase.

[0062] In another specific embodiment, the conditions of the above embodiment are applied, and the minimum offset occurs at position 3, and the maximum offset occurs at position 5. Based on the above formula, the minimum offset is obtained first, followed by the maximum offset. Substituting the data into the equation, 60° + 120° = 180° is obtained. This means that the angle of 180 degrees, or position 7, is the coarse phase of the rotor's initial phase.

[0063] It should be noted that when the angle value of the coarse phase calculated by the formula is greater than or equal to 360°, since the azimuth angles of the applied excitation current divided by the preset angles are all less than or equal to 360°, the angle value of the coarse phase calculated by the formula is subtracted by 360°, and the coarse phase is searched again.

[0064] For example, using the conditions of the above embodiment, the minimum offset occurs at position 5, and the maximum at position 11. Based on the above formula, the minimum value is taken first, followed by the maximum value. Substituting the data into the equation, we obtain 120° + 300° = 420°. Since 420° > 360°, we use 420° - 360° = 60° as the azimuth angle of the coarse phase. This means that the 60-degree angle, or position 3, represents the coarse phase of the rotor's initial phase.

[0065] S203: applying a fixed excitation current to the coarse phase at predetermined intervals, updating the coarse phase of the rotor initial phase based on the rotor rotation direction, and acquiring a first fine phase of the rotor initial phase based on the updated coarse phase of the rotor initial phase;

[0066] It should be noted that obtaining the first fine phase of the rotor initial phase also includes, during the process of obtaining the coarse phase of the rotor initial phase, if the excitation current does not cause the rotor to deflect at a certain angle, then the angle is regarded as the first fine phase of the rotor initial phase. In this case, the process of obtaining the coarse phase is skipped, and further conversion from the coarse phase to the first fine phase is no longer required.

[0067] In an exemplary embodiment, the coarse phase of the rotor initial phase is updated based on the rotor rotation direction, and the first fine phase of the rotor initial phase is obtained based on the updated coarse phase of the rotor initial phase, including: if the offset displacement of the rotor is along a first direction, the coarse phase is deflected by a preset adjustment angle in the opposite direction of the first direction, and the adjusted phase angle is used as the new coarse phase of the rotor initial phase; the excitation current is applied to the new coarse phase, and the coarse phase is updated based on the offset displacement of the rotor until the excitation current is applied to the coarse phase so that the rotor offset displacement is along the opposite direction of the first direction, at which time the coarse phase of the rotor initial position is the first fine phase of the rotor initial phase.

[0068] It is understood that the first direction is a preset positive direction or reverse direction. The adjustment angle can be adaptively adjusted based on the actual usage scenario. The smaller the adjustment angle, the longer it takes to update the coarse phase and obtain the first fine phase, but the higher the accuracy of the obtained first fine phase. Conversely, the higher the adjustment angle, the lower the accuracy of the first fine phase, and even a large error may occur, affecting the normal operation of the servo motor. Therefore, the adjustment angle can be less than or equal to 1°, preferably 1°.

[0069] For example, the adjustment angle is set to 1°, with the counterclockwise direction being the positive direction. The coarse phase of the rotor's initial phase, obtained in the previous step, is 60°. A fixed excitation current is introduced along the motor's N pole at the coarse phase. If the rotor rotates in the positive direction, the coarse phase is updated to 60°-1°=59°, and a fixed excitation current is introduced along the motor's N pole at the updated coarse phase. If the rotor still rotates in the positive direction, the coarse phase is updated to 59°-1°=58°, and the above operation is repeated. This continues until the coarse phase is updated to 55°. A fixed excitation current is introduced along the motor's N pole at the coarse phase, and the rotor moves in the reverse direction. The coarse phase at this point is then used as the first fine phase. In this embodiment, the rotor's first fine phase is 55°.

[0070] S204: Rotate the first fine phase by 180 degrees to obtain a second fine phase, apply excitation voltages of the same magnitude in the directions of the first fine phase and the second fine phase, respectively, and obtain the rotor initial phase based on the current amplitudes of the first fine phase and the second fine phase under the excitation voltage.

[0071] It should be noted that the first fine phase obtained in steps S201-S203 cannot determine the rotor's N-S polarity. In other words, the angle at which the first fine phase is located may correspond to either N or S polarity. Distinguishing the rotor's N-S polarity requires the use of the magnetic circuit saturation effect. The saturated magnetic circuit effect refers to the phenomenon in which, when a magnetic field is applied to a magnetic circuit, the magnetic flux density reaches a maximum value due to saturation of the magnetic circuit material. Thereafter, even if the magnetic field is increased further, the magnetic flux density cannot increase further.

[0072] Due to the electromagnetic saturation effect, applying voltage to the positive direction of the motor rotor (north pole) causes the stator magnetic field to be in the same direction as the rotor magnetic field, leading to oversaturation of the d-axis magnetic circuit. Applying voltage to the south pole causes the stator magnetic field to be in opposite directions from the rotor magnetic field, leading to desaturation of the d-axis magnetic circuit. The motor's direct-axis inductance decreases with oversaturation of the d-axis magnetic circuit and increases with desaturation. Therefore, the polarity can be determined based on the magnitude of the current vector at the current phase and the phase after a 180° shift.

[0073] In an exemplary embodiment, the obtaining of the rotor initial phase based on the current amplitudes of the first fine phase and the second fine phase under the excitation voltage includes: if the current amplitude of the first fine phase is greater than the current amplitude of the second fine phase, the first fine phase is the initial phase of the rotor; if the current amplitude of the first fine phase is less than the current amplitude of the second fine phase, the second fine phase is the initial phase of the rotor.

[0074] For example, after steps S201-S203, if the first fine rotor phase is 55°, the corresponding second fine phase is 55° + 180° = 235°. Voltage is applied along the N pole of the motor rotor at both the first and second fine phases, resulting in a current amplitude of 3V at the first fine phase and 5V at the second fine phase. Since the current amplitude at the second fine phase is greater than the current amplitude at the first fine phase, 235° is the initial phase of the servo motor.

[0075] As shown in FIG3 , based on the same inventive concept as the aforementioned rotor initial phase detection method, an embodiment of the present invention provides a rotor initial phase detection system 300 , which includes a first sending module 301 , a first acquisition module 302 , a second sending module 303 and a second acquisition module 304 .

[0076] Specifically, the first sending module 301 is used to apply a fixed-size excitation current to the rotor at every preset angle along a preset positive direction with the symmetry center of the rotor as the center of the circle, and the positive direction is counterclockwise or clockwise; the first acquisition module 302 is used to obtain the coarse phase of the rotor initial phase based on the displacement offset of the rotor; the second sending module 303 is used to apply a fixed-size excitation current along the coarse phase direction at every preset time interval, update the coarse phase of the rotor initial phase based on the rotor rotation direction, and obtain the first fine phase of the rotor initial phase based on the updated coarse phase of the rotor initial phase; the second acquisition module 304 is used to rotate the first fine phase 180 degrees to obtain a second fine phase, apply the same excitation voltage in the first fine phase and the second fine phase directions respectively, and obtain the rotor initial phase based on the current amplitude of the first fine phase and the second fine phase under the excitation voltage.

[0077] It should be noted that the first acquisition module 302 is further configured to sequentially acquire the displacement offset of the rotor based on the positive direction; when the displacement offset of the rotor in the positive direction reaches the maximum value first and the displacement offset of the rotor in the negative direction reaches the maximum value later, the coarse phase of the initial phase of the rotor is: θ1 = θ max +θmin -180°; when the displacement bias of the rotor in the negative direction reaches the maximum value first, and the displacement bias of the rotor in the positive direction reaches the maximum value later, the coarse phase of the initial phase of the rotor is: θ1 = θ max +θ min ; Wherein, θ1 is the coarse phase of the initial phase of the rotor, θ max is the phase angle corresponding to the maximum displacement offset of the rotor in the positive direction based on the excitation current, θ min is the phase angle corresponding to the minimum value of the displacement bias of the rotor along the negative direction based on the excitation current.

[0078] The second sending module 303 is also used to, when the bias displacement of the rotor is along a first direction, deflect the coarse phase by a preset adjustment angle in the opposite direction of the first direction, and use the adjusted phase angle as the coarse phase of the new rotor initial phase, wherein the first direction is a preset positive direction or reverse direction; apply the excitation current to the new coarse phase, and update the coarse phase based on the bias displacement of the rotor until the excitation current is applied to the coarse phase to cause the rotor bias displacement to be in the opposite direction of the first direction, at which time the coarse phase of the rotor initial position is the first fine phase of the rotor initial phase.

[0079] The second acquisition module 304 is further configured to determine that the first fine phase is the initial phase of the rotor when the current amplitude of the first fine phase is greater than the current amplitude of the second fine phase; and to determine that the second fine phase is the initial phase of the rotor when the current amplitude of the first fine phase is less than the current amplitude of the second fine phase.

[0080] Referring to FIG. 4 , an embodiment of the present invention further provides an electronic device 400, which includes at least one processor 401, a memory 402 (e.g., a non-volatile memory), a storage 403, and a communication interface 404. The at least one processor 401, the storage 402, the storage 403, and the communication interface 404 are connected together via a bus 405. The at least one processor 401 is configured to invoke at least one program instruction stored or encoded in the storage 402, so that the at least one processor 401 executes various operations and functions of the rotor initial phase detection method described in various embodiments of this specification.

[0081] In the embodiments of the present specification, the electronic device 400 may include but is not limited to: a personal computer, a server computer, a workstation, a desktop computer, a laptop computer, a notebook computer, a mobile electronic device, a smart phone, a tablet computer, a cellular phone, a personal digital assistant (PDA), a handheld device, a messaging device, a wearable electronic device, a consumer electronic device, and the like.

[0082] An embodiment of the present invention also provides a computer-readable medium carrying computer-executable instructions. When the computer-executable instructions are executed by a processor, they can be used to implement the various operations and functions of the rotor initial phase detection method described in the various embodiments of this specification.

[0083] The computer-readable medium in the present invention can be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium can be, for example, but not limited to, a system, device or component of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by an instruction execution system, device or device or used in combination with it.

[0084] In the present invention, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination thereof.

[0085] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0086] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, apparatuses, systems, and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowcharts and / or one or more blocks in the block diagrams.

[0087] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for detecting the initial phase of a rotor, applied to a servo motor control system, characterized in that, Comprising: Taking the symmetric center of the rotor as the center of a circle, applying an excitation current with a fixed magnitude to the rotor at every preset angle interval along a preset positive direction, where the positive direction is counterclockwise or clockwise; obtaining a rough phase of the initial phase of the rotor based on the displacement offset of the rotor; Applying an excitation current with a fixed magnitude to the rough phase at every preset time interval, updating the rough phase of the initial phase of the rotor based on the rotation direction of the rotor, and obtaining a first fine phase of the initial phase of the rotor based on the updated rough phase of the initial phase of the rotor; Rotating the first fine phase by 180 degrees to obtain a second fine phase, applying the same magnitude of excitation voltage in the directions of the first fine phase and the second fine phase respectively, and obtaining the initial phase of the rotor based on the current amplitude magnitudes of the first fine phase and the second fine phase under the excitation voltage.

2. The rotor initial phase detection method according to claim 1, wherein Obtaining the rough phase of the initial phase of the rotor based on the displacement offset of the rotor includes: Sequentially obtaining the displacement offsets of the rotor based on the positive direction; If the displacement offset of the rotor along the positive direction reaches the maximum value first and the displacement offset of the rotor along the negative direction reaches the maximum value later, then the rough phase of the initial phase of the rotor is: θ1 = θ max + θ min - 180° If the displacement offset of the rotor along the negative direction reaches the maximum value first and the displacement offset of the rotor along the positive direction reaches the maximum value later, then the rough phase of the initial phase of the rotor is: θ1 = θ max + θ min Among them, θ1 is the coarse phase of the initial phase of the rotor, θ max is the phase angle corresponding to the maximum value of the displacement offset of the rotor along the positive direction based on the exciting current, θ min is the phase angle corresponding to the minimum value of the displacement offset of the rotor along the negative direction based on the exciting current.

3. The rotor initial phase detection method according to claim 2, characterized in that The method further includes: If at an angle, the excitation current does not cause the rotor to deflect, then the angle is the first fine phase of the initial phase of the rotor.

4. The rotor initial phase detection method according to claim 1, wherein, The updating the rough phase of the initial phase of the rotor based on the rotation direction of the rotor and obtaining the first fine phase of the initial phase of the rotor based on the updated rough phase of the initial phase of the rotor includes: If the offset displacement of the rotor is along a first direction, then deflect the rough phase in the opposite direction of the first direction by a preset adjustment angle, and take the adjusted phase angle as the new rough phase of the initial phase of the rotor, where the first direction is the preset positive direction or the opposite direction; Applying the excitation current to the new rough phase and updating the rough phase based on the offset displacement of the rotor until applying the excitation current to the rough phase causes the offset displacement of the rotor to be in the opposite direction of the first direction. At this time, the rough phase of the initial position of the rotor is the first fine phase of the initial phase of the rotor.

5. The rotor initial phase detection method according to claim 4, wherein The preset adjustment angle is not greater than 1°.

6. The rotor initial phase detection method according to claim 1, characterized in that, The obtaining the initial phase of the rotor based on the current amplitude magnitudes of the first fine phase and the second fine phase under the excitation voltage includes: If the current amplitude of the first fine phase is greater than the current amplitude of the second fine phase, then the first fine phase is the initial phase of the rotor; If the current amplitude of the first fine phase is less than the current amplitude of the second fine phase, then the second fine phase is the initial phase of the rotor.

7. The rotor initial phase detection method according to claim 1, characterized in that, The direction of the excitation current is consistent with the direction of the N pole of the servo motor.

8. A rotor initial phase detection system, characterized in that, Comprising: A first transmission module, configured to apply an excitation current with a fixed magnitude to the rotor at intervals of a preset angle in a preset positive direction centered on the symmetric center of the rotor, where the positive direction is counterclockwise or clockwise; A first acquisition module, configured to acquire a rough phase of the initial phase of the rotor based on the displacement offset of the rotor; A second transmission module, configured to apply an excitation current with a fixed magnitude in the direction of the rough phase at intervals of a preset time, update the rough phase of the initial phase of the rotor based on the rotation direction of the rotor, and acquire a first fine phase of the initial phase of the rotor based on the updated rough phase of the initial phase of the rotor; A second acquisition module, configured to rotate the first fine phase by 180 degrees to obtain a second fine phase, apply an excitation voltage with the same magnitude in the directions of the first fine phase and the second fine phase respectively, and acquire the initial phase of the rotor based on the magnitudes of the current amplitudes of the first fine phase and the second fine phase under the excitation voltage; 9. A computer device, characterized in that, Comprising: A memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to execute the rotor initial phase detection method according to any one of claims 1-7; 10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing a computer to execute the rotor initial phase detection method according to any one of claims 1-7.

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