A control moment gyro low-speed frame motor optimization method and device

Abstract

This application relates to a method and apparatus for optimizing a low-speed frame motor for a control torque gyroscope. First, a finite element model of the basic motor is built to match the operating conditions of the control torque gyroscope, ensuring that the optimized simulation closely reflects actual working constraints. By optimizing the basic stator with an unequal tooth width structure, air gap magnetic field harmonics are effectively offset, suppressing motor cogging torque and torque pulsation. By optimizing the magnetic circuit of the basic rotor through yoke opening, the internal magnetic circuit distribution of the motor is improved, alleviating local magnetic saturation and reducing motor operating losses. Compared to traditional single-structure optimization methods, this invention performs coordinated matching optimization of the optimized stator and rotor, overcoming the limitations of single optimization methods in performance improvement. It effectively solves the problems of large torque fluctuations, poor magnetic circuit performance, and insufficient overall stability in existing frame motors, significantly improving motor output accuracy and operational stability, meeting the engineering application requirements of high precision, long lifespan, and low power consumption for control torque gyroscopes.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft attitude control and precision servo drive technology, specifically relating to a method and device for optimizing the low-speed frame motor of a control torque gyroscope. Background Technology

[0002] Spacecraft attitude control technology is an important component of the overall spacecraft control system. Its main task is to establish, maintain, adjust, and achieve high-precision stable control of the spacecraft's attitude during on-orbit flight, so as to ensure that the payload can accurately point to the predetermined target and complete the intended mission.

[0003] Control torque gyroscopes are core devices for high-precision attitude control, widely used in spacecraft attitude stabilization and maneuvering scenarios. Their frame motors, as key actuators for torque output, face stringent requirements regarding torque output accuracy, operational stability, loss levels, and service life. Existing conventional permanent magnet synchronous motor structures, when adapted to control torque gyroscope operating conditions, generally exhibit problems such as excessive cogging torque and significant torque pulsation, easily causing motor vibration and affecting the system's attitude control accuracy.

[0004] Currently, most optimization methods for the electromagnetic performance of motors focus on optimizing a single stator structure or improving a single rotor magnetic circuit, resulting in relatively simplistic optimization approaches. Optimizing the stator tooth profile alone cannot simultaneously address the issues of magnetic circuit saturation and losses, while optimizing the rotor structure alone cannot effectively suppress cogging torque fluctuations. The improvement effect of a single optimization method is limited, failing to achieve a synergistic improvement in the overall electromagnetic performance of the motor and thus failing to meet the engineering requirements of high-precision control torque gyroscopes. Summary of the Invention

[0005] Therefore, it is necessary to provide a method and apparatus for optimizing the low-speed frame motor of the control torque gyroscope, which can solve the above-mentioned technical problems.

[0006] The first aspect of this invention provides a method for optimizing a low-speed frame motor for controlling a torque gyroscope, the method comprising:

[0007] A basic motor finite element model is constructed based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor; the basic motor finite element model includes the basic stator and the basic rotor. The cogging torque of the basic stator is optimized by performing cogging torque optimization on the unequal tooth width to obtain the optimized stator; The magnetic circuit of the basic rotor is optimized by opening holes in the rotor yoke to obtain the optimized rotor; The optimized stator and the optimized rotor are then subjected to collaborative optimization to obtain the target motor model.

[0008] In one embodiment, the above-mentioned construction of a basic motor finite element model based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor includes: Electromagnetic design processing of the frame motor is performed based on the overall performance indicators of the control torque gyroscope to obtain the motor design parameters; Based on the control torque output of the control torque gyroscope and the transmission relationship between the frame drive mechanism, the motor design parameters are matched and modeled to obtain the motor electromagnetic model; Two-dimensional and three-dimensional finite element simulation analysis and model assignment processing were performed on the electromagnetic model of the motor to obtain the basic finite element model of the motor for optimization calculation.

[0009] In one embodiment, the above-mentioned cogging torque optimization process on the basic stator with unequal tooth widths results in an optimized stator comprising: The stator teeth of the basic stator are grouped and offset to obtain a stator structure with unequal tooth width; An analytical model of cogging torque is established based on the air gap magnetic flux density of the motor corresponding to the stator structure with unequal tooth width. The cogging torque analytical model is processed by finite element analysis based on multiple pre-set offset angle schemes to obtain the optimized stator.

[0010] In one embodiment, the above-mentioned analytical model for cogging torque based on the air gap magnetic flux density of the motor corresponding to the unequal tooth width stator structure includes: Fourier expansion was performed on the air gap magnetic flux density of the motor with unequal tooth width stator structure to obtain the amplitude and phase parameters of each order of spatial harmonics. Based on the amplitude and phase parameters of each order of spatial harmonics, the correspondence between the energy stored in the air gap magnetic field and the cogging torque is solved using the electromagnetic energy method and the principle of virtual work. An analytical model for cogging torque is constructed based on the air gap permeability function modulated by stator tooth offset, which can characterize the influence of stator tooth offset angle on cogging torque.

[0011] In one embodiment, the above-mentioned finite element analysis calculation of the cogging torque analytical model based on multiple pre-set offset angle schemes yields an optimized stator including: Finite element simulations were performed on each offset angle scheme to obtain multiple sets of electromagnetic performance simulation data; Based on the electromagnetic performance simulation data, the cogging torque attenuation rate is calculated and the target offset angle is selected to obtain the optimized stator.

[0012] In one embodiment, the above-described magnetic circuit optimization process of opening the rotor yoke on the basic rotor results in an optimized rotor comprising: The yoke region of the basic rotor is processed by opening a structural layout to obtain an initial rotor structure with yoke openings. Electromagnetic simulation was performed on the initial rotor structures with different opening sizes and positions to obtain multiple sets of rotor magnetic circuit performance data; Based on the magnetic circuit performance data of each group of rotors, the magnetic circuit characteristics and electromagnetic performance are compared and analyzed, the target opening parameters are selected, and the rotor with optimized magnetic circuit is obtained.

[0013] A second aspect of the present invention provides a control torque gyroscope low-speed frame motor optimization device, the device comprising: The modeling module is used to construct a basic motor finite element model based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor; the basic motor finite element model includes the basic stator and the basic rotor. The stator optimization module is used to optimize the cogging torque of the basic stator with unequal tooth widths to obtain an optimized stator. The rotor optimization module is used to optimize the magnetic circuit of the yoke opening of the basic rotor to obtain the optimized rotor. The collaborative optimization module is used to perform collaborative optimization on the optimized stator and the optimized rotor to obtain the target motor model.

[0014] A third aspect of the present invention also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the method described in the first aspect.

[0015] A fourth aspect of the present invention also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps of the method described in the first aspect.

[0016] A fifth aspect of the present invention also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the steps of the method described in the first aspect.

[0017] Compared with the prior art, the technical effects achieved by the present invention are as follows: The aforementioned optimization method and device for low-speed frame motors for control torque gyroscopes first establishes a finite element model of the basic motor to match the operating conditions of the control torque gyroscope, ensuring that the optimized simulation closely matches the actual working constraints. By optimizing the basic stator with an unequal tooth width structure, air gap magnetic field harmonics are effectively offset, suppressing motor cogging torque and torque pulsation. By optimizing the magnetic circuit of the basic rotor through yoke opening, the internal magnetic circuit distribution of the motor is improved, alleviating local magnetic saturation and reducing motor operating losses. Compared to traditional single-structure optimization methods, this invention performs coordinated matching optimization of the optimized stator and rotor, overcoming the limitations of single optimization methods in performance improvement. It effectively solves the problems of large torque fluctuations, poor magnetic circuit performance, and insufficient overall stability in existing frame motors, significantly improving motor output accuracy and operational stability, meeting the engineering application requirements of high precision, long lifespan, and low power consumption for control torque gyroscopes. Attached Figure Description

[0018] Figure 1 This is an application environment diagram of the optimization method for controlling the low-speed frame motor of the torque gyroscope in one embodiment; Figure 2 This is a flowchart illustrating the optimization method for the low-speed frame motor of the control torque gyroscope in one embodiment; Figure 3 This is a flowchart illustrating the process of constructing a basic motor finite element model in one embodiment; Figure 4 This is a flowchart illustrating the optimized stator obtained in one embodiment. Figure 5 This is a flowchart illustrating the process of establishing an analytical model for cogging torque in one embodiment. Figure 6 This is a flowchart illustrating the process of obtaining the optimized stator in one embodiment; Figure 7 This is a schematic diagram of the magnetic circuit optimization process for opening holes in the rotor yoke in one embodiment; Figure 8 This is a structural block diagram of a low-speed frame motor optimization device for controlling a torque gyroscope in one embodiment. Figure 9 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] First, before introducing the technical solutions of the embodiments of this application in detail, the technical background on which the embodiments of this application are based will be introduced.

[0021] Spacecraft attitude control technology is a crucial component of the overall spacecraft control system. Its primary task is to establish, maintain, adjust, and maintain the spacecraft's attitude with high precision during on-orbit flight, ensuring that the payload accurately points to its intended target and completes its mission. With the development of space missions such as deep space exploration, space science experiments, remote sensing and mapping, communication and navigation, and space telescopes, the requirements for spacecraft attitude control accuracy, response speed, stability, and long-term reliability are constantly increasing. For example, high-resolution remote sensing satellites require attitude stabilization accuracy down to the arcsecond level or even below, while space telescopes require extremely high pointing stability during long-term observations. Therefore, the attitude control system has become one of the key technologies affecting the overall performance of spacecraft.

[0022] Modern spacecraft attitude control systems typically consist of an attitude measurement unit (ATU), an attitude controller, and attitude actuators. The ATU acquires the spacecraft's current attitude information; the attitude controller calculates control commands based on attitude errors; and the attitude actuators generate control torque based on these commands to adjust the spacecraft's attitude. Therefore, the control performance of the attitude actuators directly affects the dynamic response speed, control accuracy, and stability of the spacecraft's attitude control system.

[0023] Currently, commonly used attitude actuators in spacecraft mainly include thrusters, reaction flywheels, and control moment gyroscopes. Thrusters can provide large control torques, but they consume propellant, making it difficult to meet the requirements of long-term continuous operation. Reaction flywheels have advantages such as high control precision, simple structure, and suitability for fine attitude control, and have been widely used in small and medium-sized spacecraft. However, their output control torque is limited by the flywheel motor's capability, resulting in lower control efficiency during high-angle, rapid attitude maneuvers.

[0024] To meet the needs of large spacecraft, high-inertia spacecraft, and rapid attitude maneuvering missions, control moment gyroscopes (CMGs) have been widely researched and applied because they can output control torques far greater than those of reaction wheels. Currently, control moment gyroscopes have become crucial actuators for attitude control in high-performance spacecraft such as large satellites, space stations, and space telescopes.

[0025] A control torque gyroscope is an attitude actuator that generates gyroscopic torque by utilizing the change in the angular momentum vector direction of a high-speed rotating flywheel. Its basic components include a high-speed flywheel, a motor, a frame mechanism, a frame drive motor, and a control system. When the high-speed flywheel maintains a constant rotational speed, it drives the frame to rotate around its axis, causing a change in the direction of the flywheel's angular momentum. This generates a gyroscopic control torque perpendicular to both the flywheel's angular momentum and the frame's angular velocity, thus achieving spacecraft attitude adjustment.

[0026] Because control moment gyroscopes offer high output torque, high control efficiency, no propellant consumption, and continuous operation, they are particularly suitable for rapid attitude maneuvering and high-precision attitude control of large spacecraft. Control moment gyroscopes can be classified according to their structure into single-frame control moment gyroscopes, double-frame control moment gyroscopes, and variable-speed control moment gyroscopes, among which the single-frame control moment gyroscope is the most widely used due to its simple structure and mature control mechanism.

[0027] The output torque of a moment gyroscope is determined by both the angular momentum of the high-speed flywheel and the angular velocity of the frame. Therefore, the frame drive motor, as a crucial actuator of the moment gyroscope, directly impacts its dynamic response and attitude control accuracy. Frame motors typically operate at low speeds, with high torque, frequent starts and stops, and in both forward and reverse rotation. During the attitude maintenance phase of a spacecraft, they may even need to operate at near-zero speeds for extended periods while continuously outputting stable and consistent driving torque. Therefore, the frame motor not only requires a large low-speed output torque but also low torque ripple, high operational smoothness, and high reliability.

[0028] Currently, permanent magnet synchronous motors (PMSMs) are commonly used as actuators in control moment gyroscope frame drive systems. PMSMs offer advantages such as high power density, high efficiency, compact structure, and high control precision, meeting the drive performance requirements of spacecraft attitude control systems. However, when the motor operates at low speeds for extended periods, its electromagnetic performance is susceptible to influences from factors such as cogging effect, magnetic circuit structure, and rotor structure. This leads to increased cogging torque and electromagnetic torque pulsation, causing problems such as output torque fluctuations, low-speed creep, decreased speed stability, and reduced servo control precision. These issues further affect the continuity and stability of the control moment gyroscope's output torque, hindering high-precision attitude control of spacecraft.

[0029] To improve low-speed performance, existing research typically employs methods such as optimizing the electromagnetic structure of the motor to reduce cogging torque and torque ripple. These methods include optimizing skewed slots, skewed poles, magnet pole arcs, stator and rotor dimensions, and magnetic circuit parameters. While these methods can reduce cogging torque and improve output torque smoothness to some extent, they still present challenges such as complex manufacturing processes, high processing difficulty, and the possibility that some optimization measures may reduce average electromagnetic torque or affect mechanical strength. Consequently, it remains difficult to simultaneously meet the performance requirements of low-speed high-torque output capability, torque ripple suppression, and structural reliability.

[0030] In recent years, improving the low-speed performance of motors through stator tooth profile optimization and rotor magnetic circuit optimization has gradually become a research hotspot. Among these, unequal stator tooth width design can alter the air gap magnetic permeability distribution, reducing cogging torque; while openings in the rotor yoke can optimize magnetic flux distribution and improve electromagnetic torque output characteristics. However, most existing studies analyze these two optimization measures separately, lacking a systematic study of the electromagnetic performance, torque ripple, stator natural frequency, and rotor mechanical strength under their synergistic effect. The comprehensive optimization design method still needs further improvement.

[0031] Therefore, how to further reduce cogging torque and electromagnetic torque pulsation, and improve low-speed operation smoothness and output torque accuracy by optimizing the stator tooth structure and rotor magnetic circuit structure, while ensuring the motor's output capacity and structural reliability, remains a pressing technical problem in the design of control torque gyroscope drive motors.

[0032] The problems with the above-mentioned existing technology are as follows: (1) The control moment gyroscope frame motor operates under conditions of low speed, high torque and frequent forward and reverse rotation. Its output performance directly affects the control torque generated by the control moment gyroscope and the attitude control accuracy of the spacecraft. Although the existing control moment gyroscope frame motor can meet the basic drive requirements, there are still the following shortcomings in the design of the motor's electromagnetic structure.

[0033] The existing electromagnetic design of low-speed, high-torque frame motors lacks optimization for the operating conditions of control torque gyroscopes, making it difficult to meet the requirements for stable low-speed output.

[0034] Control torque gyroscope frame motors operate at low speeds, with high torque, frequent starts and stops, and forward and reverse rotation, placing high demands on the motor's output torque, torque density, and low-speed operational stability. However, most existing low-speed permanent magnet synchronous motor designs employ conventional electromagnetic design methods, primarily relying on general industrial servo motor design principles for parameter selection and structural design, lacking specific optimization tailored to the operating characteristics of control torque gyroscopes.

[0035] In existing designs, there is a strong coupling relationship between parameters such as the main dimensions of the stator and rotor, slot-pole matching, permanent magnet dimensions, and magnetic circuit structure. If the design is not reasonable, it can easily lead to problems such as uneven air gap magnetic flux density distribution, insufficient electromagnetic torque, low torque density, and decreased efficiency. At the same time, due to the lack of systematic verification between prototype testing and theoretical design, it is difficult to further optimize the motor design parameters, affecting the overall performance of the frame motor under low-speed, high-torque conditions.

[0036] Therefore, existing technologies lack an electromagnetic design method that addresses the low-speed operation characteristics of control torque gyroscopes, in order to balance output capability, efficiency, and low-speed performance.

[0037] (2) Existing cogging torque suppression methods have limited effectiveness and lack optimization design and theoretical analysis based on stator unequal tooth width. Control torque gyroscope frame motors typically employ a slotted stator structure. During motor operation, periodic changes in magnetic permeability between the stator slots and the rotor permanent magnets generate cogging torque. Especially at low speeds, the cogging torque accounts for a relatively high proportion of the output torque, easily causing speed fluctuations, torque pulsations, and low-speed creep, thus affecting the stability of the control torque gyroscope's output torque and the accuracy of attitude control.

[0038] Currently, methods for reducing cogging torque mainly include measures such as skewed slots, skewed poles, and optimization of magnet pole arcs. However, these methods generally suffer from problems such as complex processing, high manufacturing costs, reduced average electromagnetic torque, or limited applicability. Furthermore, existing technologies rarely employ stator unequal tooth width structures to optimize air gap magnetic permeability distribution. There is a lack of in-depth analysis of the air gap magnetic flux density variation and cogging torque formation mechanism under different tooth offset methods. There is also a lack of systematic research on establishing an analytical model of cogging torque based on Fourier decomposition and verifying the optimization effect using the finite element method. Therefore, it is difficult to determine the optimal tooth offset angle to effectively suppress cogging torque.

[0039] Therefore, existing technologies still lack a design method that can reduce cogging torque and improve low-speed operation smoothness from both theoretical analysis and structural optimization perspectives.

[0040] (3) There is insufficient research on the optimization of rotor magnetic circuit structure, and there is a lack of stator and rotor co-optimization design methods.

[0041] The electromagnetic torque output of a motor is not only affected by the stator structure, but also closely related to the rotor magnetic circuit structure. The rotor of existing control torque gyroscope frame motors usually adopts a complete yoke structure, which has an unreasonable magnetic flux distribution and local magnetic density concentration, resulting in large electromagnetic torque pulsation and affecting the stability of low-speed output.

[0042] In recent years, although some studies have proposed improving the magnetic circuit distribution by openings in the rotor yoke, research on the influence of structural parameters such as the shape, size, and number of openings on electromagnetic torque and torque ripple is still incomplete, and systematic parameter optimization methods are lacking. Furthermore, existing studies mostly optimize the stator or rotor separately, rarely considering the coupling effect between the stator's unequal tooth width and the rotor yoke openings, lacking a synergistic optimization design. A systematic analysis of the comprehensive performance of the optimized motor, including average electromagnetic torque, torque ripple, electromagnetic performance, stator natural frequency, and rotor mechanical strength, is also lacking, making it difficult to balance electromagnetic performance and structural reliability.

[0043] Based on this, this application provides a method and apparatus for optimizing the low-speed frame motor of a control torque gyroscope, aiming to solve the above-mentioned technical problems.

[0044] The method for optimizing the low-speed frame motor of the control torque gyroscope provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104 or placed on the cloud or other network servers. Terminal 102 first builds a basic motor simulation model adapted to the control torque gyroscope operating conditions. It then reduces cogging torque through a stator with unequal tooth width and improves magnetic circuit saturation by opening holes in the rotor yoke. Finally, it performs collaborative matching verification on the optimized stator and rotor. Terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, and tablets. Server 104 can be implemented using a standalone server or a server cluster consisting of multiple servers.

[0045] In one exemplary embodiment, such as Figure 2 As shown, a method for optimizing the low-speed frame motor of a control torque gyroscope is provided, which is then applied to... Figure 1 Taking terminal 102 as an example, the explanation includes the following steps: S201, construct a basic motor finite element model based on the overall performance index of the control torque gyroscope and the main parameters of the motor; the basic motor finite element model includes the basic stator and the basic rotor.

[0046] The basic motor finite element model refers to the electromagnetic field simulation model built using the constraints of the control torque gyroscope and the electromagnetic dimensional parameters of the motor. It includes the complete stator and rotor structures and can simulate various electromagnetic performances of the motor, serving as the simulation platform for subsequent structural optimization. The basic stator refers to the original stator core structure with uniform tooth width design and no modifications to the tooth profile. The basic rotor refers to the original permanent magnet synchronous rotor structure with no openings in the yoke and no adjustments to the magnetic circuit.

[0047] This application embodiment combines the hard indicators such as the weight, power consumption, output torque, and service life of the control torque gyroscope, matches the rated torque, speed, and power parameters of the frame motor, and sequentially determines the motor pole slot matching, stator and rotor inner and outer diameters, core length, air gap, slot type, permanent magnet, and winding parameters to build an electromagnetic model of the motor; then, the model is meshed, boundary conditions and operating conditions are set to generate a basic motor finite element model that can be used for simulation calculation. The model contains a basic stator with original uniform tooth width and a basic rotor without openings in the yoke.

[0048] S202, the cogging torque of the basic stator is optimized by performing cogging torque optimization on the unequal tooth width to obtain the optimized stator.

[0049] This application takes the basic stator as the optimization object, keeping the overall size, slot shape and winding installation space of the stator unchanged, and sets different circumferential offset angles for each group of stator teeth to form an unequal tooth width structure; sets multiple offset schemes to carry out finite element simulation, extracts tooth cogging torque and air gap magnetic field harmonic data of each scheme, and selects the optimal offset parameters based on the tooth cogging torque reduction effect as the evaluation criterion, and finally obtains an optimized stator that can effectively suppress tooth cogging torque.

[0050] In this embodiment of the invention, a stator tooth circumferential offset is used to form an unequal tooth width structure. In other embodiments, the unequal tooth width structure can also be formed by changing the stator tooth top width, tooth root width, tooth shoulder size, tooth groove opening width, or different tooth width combinations. As long as the spatial distribution of air gap magnetic permeability can be changed and the periodic change of tooth groove magnetic permeability can be weakened, it falls within the protection scope of this invention.

[0051] Furthermore, the grouping method of stator teeth is not limited to the grouping form in the embodiment. It can be arranged in a way such as equal interval grouping, staggered grouping, periodic grouping or non-uniform grouping according to the motor slot pole matching relationship. The offset angle of different stator teeth can also be achieved by using the same offset amount, different offset amounts or continuously changing offset amounts.

[0052] S203, perform magnetic circuit optimization processing on the basic rotor by opening holes in the rotor yoke to obtain the optimized rotor.

[0053] This application takes the basic rotor as the optimization object and arranges the opening structure in the rotor yoke region between adjacent permanent magnets. Various parameters such as the opening shape, opening size, opening number and opening position are adjusted in sequence. Multiple schemes are simulated and compared to compare the internal magnetic flux distribution, local magnetic saturation, average output torque and torque pulsation of the rotor. At the same time, the mechanical strength and dynamic balance performance of the rotor are taken into account to determine the optimal opening scheme and obtain the optimized rotor with improved magnetic circuit performance.

[0054] In this embodiment of the invention, the rotor yoke weight reduction opening improves the magnetic circuit distribution. In other embodiments, the opening can be circular, elliptical, oblong, waist-shaped, rectangular with rounded corners, polygonal, arc-shaped, or other regular or irregular hole shapes; the number of openings can be single hole, multiple holes, or a combination of holes; the position of the opening can be adjusted radially, circumferentially, or simultaneously radially and circumferentially; the size of each opening can also be the same or different. As long as it can improve the rotor magnetic flux distribution, reduce local magnetic saturation, and improve the magnetic energy utilization rate of the permanent magnet, it falls within the protection scope of this invention.

[0055] In addition to openings in the yoke, the magnetic circuit distribution of the rotor yoke can also be adjusted by methods such as yoke thinning, local grooves, magnetic flux adjustment slots, non-uniform yoke thickness structures, magnetic barrier structures, or local magnetic conduction structure optimization, so as to improve the magnetic density distribution and increase the average electromagnetic torque.

[0056] S204, the optimized stator and the optimized rotor are jointly optimized to obtain the target motor model.

[0057] The target motor model is the final motor simulation model that meets all operating conditions of the control torque gyroscope after the sub-rotor and rotor have undergone structural optimization and matching verification.

[0058] In this embodiment, the separately optimized stator and rotor structures are assembled to form a complete motor simulation model. Multi-condition joint electromagnetic field simulation is carried out, and comprehensive indicators such as air gap magnetic flux density, output torque, torque pulsation, and core loss under the coupling effect of stator and rotor are analyzed simultaneously. The performance differences between single stator optimization, single rotor optimization and stator-rotor joint optimization are compared, and the scheme that meets the standards in terms of comprehensive electromagnetic performance and structural reliability is selected, and the final target motor model is output.

[0059] In this embodiment of the invention, a stator unequal tooth width structure and a rotor yoke opening structure are used for synergistic optimization. In other embodiments, the two optimization measures can be applied individually or in combination with permanent magnet pole arc coefficient optimization, magnet offset, magnet segmentation, skewed pole structure, auxiliary slot structure, stator skewed slot, or other electromagnetic optimization measures that reduce cogging torque and improve air gap magnetic field distribution, in order to further improve the overall performance of the motor.

[0060] This invention first establishes a basic motor simulation model adapted to the operating conditions of a control torque gyroscope. It then reduces cogging torque by using a stator with unequal tooth width and improves magnetic circuit saturation by opening holes in the rotor yoke. Finally, it performs a collaborative matching verification on the optimized stator and rotor to compensate for the limited performance improvement of a single structure optimization. This effectively reduces torque fluctuations under low-speed motor conditions, improves average output torque and magnetic flux utilization, and simultaneously considers the structural strength of the motor and its long-term on-orbit reliability. It significantly improves the stability and accuracy of attitude control of the control torque gyroscope. Moreover, it relies solely on core structure optimization, without the need to add permanent magnets or winding consumables, making it easy to manufacture and implement, and highly practical for engineering applications.

[0061] In one exemplary embodiment, based on the above embodiments, please refer to... Figure 3 This application embodiment relates to the process of constructing a basic motor finite element model based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor, including the following steps: S301, based on the overall performance indicators of the control torque gyroscope, performs electromagnetic design processing on the frame motor to obtain the motor design parameters.

[0062] The overall performance indicators of the control torque gyroscope include constraints for on-orbit use of spacecraft, such as overall weight, power consumption, output torque, design life, and rotor start-up time, which are the hard boundaries of motor design. Motor design parameters include all electromagnetic structure parameters such as motor pole slot matching, stator and rotor dimensions, core length, air gap length, stator slot type, permanent magnet specifications, and number of winding turns.

[0063] In this embodiment, the terminal first reviews all the constraints of the control torque gyroscope, such as its weight, power consumption, torque output, and service life. Combined with the requirements of low-speed continuous operation and high torque output of the frame motor, the terminal determines the complete set of structural and electrical parameters, such as the inner and outer diameters of the motor, the length of the iron core, the air gap, the slot type, the size of the permanent magnet, and the winding specifications, and outputs the complete motor design parameters.

[0064] S302, based on the control torque output of the control torque gyroscope and the transmission relationship of the frame drive mechanism, the motor design parameters are matched and modeled to obtain the motor electromagnetic model.

[0065] Among them, the transmission relationship of the frame drive mechanism refers to the corresponding law of torque and speed transmission between the control torque gyroscope frame, transmission components and drive motor, which is used to calculate the rated working parameters of the motor.

[0066] An electromagnetic model of an electric motor refers to a theoretical electromagnetic design model that only includes the motor's geometry, magnetic circuit, windings, and permanent magnets, without simulation meshes or operating condition boundary settings.

[0067] In this embodiment, the terminal calculates the rated torque, rated speed and power level of the motor based on the gyroscope output torque and the frame transmission ratio, and imports all the motor design parameters obtained in the previous step into the modeling software to build an electromagnetic model of the motor that includes the stator, rotor, permanent magnet and winding geometry.

[0068] S303 performs two-dimensional and three-dimensional finite element simulation analysis and model assignment on the electromagnetic model of the motor to obtain the basic finite element model of the motor for optimization calculation.

[0069] In this embodiment, the material properties of the core, permanent magnet, and windings are configured for the electromagnetic model of the motor. Two-dimensional and three-dimensional computational meshes are divided, and boundaries and operating conditions such as vacuum, temperature, and load are added. Preliminary electromagnetic simulation is carried out to verify the rationality of the model. After all simulation configurations are completed, a basic motor finite element model is generated that can be used for subsequent stator and rotor structure optimization calculations.

[0070] Specifically, this invention uses a control moment gyroscope as the application object and performs electromagnetic design on a low-speed frame motor based on the overall performance indicators of the control moment gyroscope. The overall performance requirements of the control moment gyroscope include: total weight not exceeding 7.1 kg, maximum power consumption less than 44 W, steady-state power consumption less than 10 W, design life not less than 5 years, maximum output control torque reaching 3 N·m, and high-speed rotor start-up time not exceeding 15 minutes. Under these constraints, the frame motor must meet the application requirements of low-speed continuous operation, high torque output, high efficiency, high reliability, and long lifespan.

[0071] Based on the control torque output of the control torque gyroscope and the transmission relationship of the frame drive mechanism, the rated output torque, rated speed, and power rating of the frame motor are determined. Considering installation space, heat dissipation conditions, and overall weight requirements, the main electromagnetic parameters of the motor are designed. First, the main dimensional parameters of the motor, such as pole slot fit, stator outer diameter, stator inner diameter, core length, and air gap length, are determined. Then, the stator slot type, rotor structure, permanent magnet dimensions, permanent magnet magnetization method, and winding parameters are designed, establishing an electromagnetic model of a low-speed, high-torque permanent magnet synchronous motor.

[0072] After completing the basic electromagnetic design, two-dimensional and three-dimensional finite element analysis was performed on the motor to calculate electromagnetic performance parameters such as no-load back EMF, air gap magnetic flux density distribution, electromagnetic torque, efficiency, power factor, and losses. Combined with temperature rise analysis and mechanical structure analysis, the motor design scheme was comprehensively evaluated. Based on this, a prototype was manufactured, and a motor performance testing platform was built. No-load tests, locked-rotor tests, load tests, and efficiency tests were conducted on the prototype. The finite element calculation results were compared with the prototype test results to verify the correctness of the electromagnetic design and the accuracy of the model calculations. This provides a basic motor model for subsequent optimization of stator tooth width inequality and rotor yoke opening optimization.

[0073] This invention conducts electromagnetic design of the motor based on the actual constraints of the control torque gyroscope, accurately matches the rated parameters of the motor with the transmission relationship, and improves the simulation configuration of the model through two-dimensional and three-dimensional finite element methods. It builds a basic finite element model of the motor that fits the actual working conditions on the track, ensuring that the simulation results of subsequent optimization of stator tooth width and rotor yoke opening are real and reliable. It provides an accurate and unified simulation benchmark for stator and rotor collaborative optimization, effectively reduces the performance deviation between simulation and actual prototype, and improves the overall optimization design accuracy of the motor.

[0074] In one exemplary embodiment, based on the above embodiments, please refer to... Figure 4 The embodiments of this application involve optimizing the cogging torque of a basic stator with unequal tooth widths to obtain an optimized stator. The process includes the following steps: S401, the stator teeth of the basic stator are grouped and offset to obtain a stator structure with unequal tooth width.

[0075] Among them, the unequal tooth width stator structure refers to a stator core structure in which the equivalent tooth width at the air gap is not equal after the stator teeth are offset at different angles.

[0076] In this embodiment, the overall shape of the stator, the slot size, and the winding installation space are kept unchanged, and all stator teeth are divided into several tooth groups; different circumferential offset angles are assigned to different tooth groups, and the equivalent tooth widths differ after the stator teeth are offset, forming a stator structure with unequal tooth widths.

[0077] S402, based on the air gap magnetic flux density of the motor corresponding to the unequal tooth width stator structure, an analytical model of cogging torque is established.

[0078] Among them, the air gap magnetic flux density is the magnetic induction intensity of a specified rotor gap region, which directly determines the magnitude of the motor's magnetic field harmonics and cogging torque. The cogging torque analytical model is a mathematical model derived from magnetic field harmonics and electromagnetic energy theory, which can quantitatively describe the relationship between the stator tooth offset angle and the cogging torque.

[0079] In this embodiment, the magnetic flux density distribution data of the air gap of the motor under the unequal tooth width structure is extracted, and the amplitude and phase of each order of magnetic field harmonics are obtained by Fourier decomposition of the air gap magnetic flux density. Combining the electromagnetic energy method and the principle of virtual work, the air gap magnetic permeability function after offset modulation is introduced to build an analytical model that can characterize the influence of the offset angle on the tooth cogging torque.

[0080] S403, based on multiple pre-set offset angle schemes, performs finite element analysis on the cogging torque analytical model to obtain the optimized stator.

[0081] Among them, the offset angle scheme refers to setting multiple sets of stator tooth offsets within a limited angle range at fixed step sizes to form multiple sets of comparative simulation schemes.

[0082] In this embodiment, all other structural, electrical, and operating parameters of the motor are fixed throughout the simulation, and only the stator tooth offset angle is changed. Multiple offset schemes are set at fixed step sizes within a preset angle range, and full-cycle finite element simulations are carried out one by one. Cogging torque and magnetic field harmonic data of each scheme are collected. The optimal offset angle is compared and selected by using the cogging torque reduction rate as the evaluation index, and finally the optimized stator is obtained.

[0083] Specifically, the process of designing stator tooth slot grouping and unequal tooth width is as follows: Based on the completion of the basic electromagnetic design of the frame motor, the stator slot structure was optimized to reduce the cogging torque when the motor is running at low speed.

[0084] Traditional permanent magnet synchronous motors have stator teeth of uniform width, resulting in a strictly periodic change in air gap permeability during rotor permanent magnet rotation, thus generating significant cogging torque. This invention reduces the periodic change in air gap permeability by altering the circumferential distribution of the stator teeth to create a structure with unequal tooth widths.

[0085] In practice, the stator teeth are first grouped according to the number of motor slots, with each group containing several adjacent stator teeth. Then, while ensuring that the winding arrangement and slot dimensions remain unchanged, different circumferential offset angles are applied to each group of stator teeth, causing some stator teeth to offset clockwise and others counterclockwise, thus forming an unequal tooth width structure in the stator. The offset angle of each tooth is adjusted according to preset parameters, and its offset range meets the requirements of motor processing and winding installation.

[0086] Through the above structural design, without changing the overall size of the motor and the winding structure, the air gap magnetic permeability distribution is changed, and the amplitude of the cogging magnetic reluctance change is reduced, thereby achieving the purpose of weakening the cogging torque.

[0087] This invention forms an unequal tooth width structure by grouping and offsetting stator teeth, and constructs an analytical model of tooth cogging torque by combining it with air gap magnetic flux density harmonic analysis. The optimal tooth offset parameters are selected by multi-set offset angle scanning simulation, which can significantly offset air gap magnetic field harmonics and suppress tooth cogging torque, effectively improving the problem of torque fluctuation at low speed of motor. At the same time, the entire optimization has complete theoretical support, avoiding reliance on empirical calculations and improving the efficiency and reliability of stator structure optimization results.

[0088] In one exemplary embodiment, based on the above embodiments, please refer to... Figure 5 The embodiments of this application involve the following steps in establishing an analytical model of cogging torque based on the air gap magnetic flux density of a motor with unequal tooth width stator structure: S501 performs Fourier expansion on the air gap magnetic flux density of a motor with unequal tooth width stator structure to obtain the amplitude and phase parameters of each order of spatial harmonics.

[0089] Among them, the spatial harmonic amplitude and phase parameters refer to the intensity and spatial distribution characteristics of each order of magnetic field harmonics after decomposition.

[0090] In this embodiment, the terminal collects the air gap magnetic flux density distribution data of the motor under the stator with unequal tooth width, performs Fourier decomposition on the air gap magnetic flux density that changes periodically along the circumference, and separates the zero-order average magnetic field, the fundamental magnetic field and multiple higher-order harmonics, and calculates the amplitude and phase parameters corresponding to each spatial harmonic.

[0091] S502, based on the amplitude and phase parameters of each order of spatial harmonics, uses the electromagnetic energy method and the principle of virtual work to solve the correspondence between the energy stored in the air gap magnetic field and the cogging torque.

[0092] Among them, the electromagnetic energy method refers to the electromagnetic field analysis method that analyzes electromagnetic torque by calculating the magnetic field energy stored in the air gap region. The virtual work principle is the fundamental theory for deriving cogging torque by utilizing the relationship between magnetic field energy storage and rotor position.

[0093] In this embodiment, the terminal substitutes the harmonic parameters of each order into the air gap magnetic field energy storage calculation formula to obtain the total air gap energy storage under different rotor rotation angles; based on the principle of virtual work, the relationship between magnetic field energy storage and rotor mechanical rotation angle is calculated, and a mapping relationship between the energy storage change and the cogging torque is established.

[0094] S503, based on the air gap permeability function after stator tooth offset modulation, constructs an analytical model of cogging torque that can characterize the influence of stator tooth offset angle on cogging torque.

[0095] Among them, the air gap permeability function is a function used to describe the change of the stator-rotor gap magnetic reluctance with the circumferential position of the motor. Stator tooth offset will change the distribution of this function.

[0096] In this embodiment, the terminal introduces the periodically changing air gap permeability function caused by stator tooth offset. Combined with the magnetic field energy storage and tooth cogging torque relationship obtained above, and integrating variables such as harmonic amplitude, phase, and tooth offset angle, a complete tooth cogging torque analytical model is built. This model can intuitively reflect the change law of tooth cogging torque when the stator tooth offset angle changes.

[0097] The specific process of this application embodiment is as follows: (1) Fourier expansion of air gap magnetic flux density: To analyze the impact of the stator's unequal tooth width structure on the cogging torque, it is first necessary to perform a Fourier expansion on the motor's air gap magnetic flux density.

[0098] The air gap is a tiny gap between the inner circle of the stator core and the outer circle of the rotor. This area is the main channel for the transmission of the motor's magnetic field. When the rotor permanent magnet rotates, the magnetic field generated by the permanent magnet enters the stator through the air gap. Therefore, the distribution of the air gap magnetic flux density directly determines the magnitude of the motor's output torque and cogging torque.

[0099] For an ideal permanent magnet synchronous motor, the air gap magnetic flux density should exhibit a standard sinusoidal distribution. However, in actual motors, due to factors such as stator slotting, permanent magnet shape, magnetization method, air gap length variation, and core magnetic saturation, the actual air gap magnetic flux density deviates from the ideal sinusoidal wave, resulting in the superposition of multiple magnetic field waveforms at different frequencies. Therefore, to analyze the influence of magnetic fields of different frequencies on cogging torque, it is necessary to decompose the complex air gap magnetic flux density waveform into multiple simple sine waves.

[0100] This invention employs Fourier series expansion to decompose the air gap magnetic flux density along the circumference of the motor. Let the distribution function of the air gap magnetic flux density along the circumference be: .

[0101] in, express Air gap magnetic flux density at the mechanical angle position; This refers to the mechanical rotation angle of the motor.

[0102] Since the air gap magnetic flux density is periodic, it can be represented as a superposition of multiple sine waves of different frequencies, i.e.:

[0103] in, Indicates the average magnetic flux density of the air gap; This represents the amplitude of the nth spatial harmonic magnetic flux density; Indicates the number of pole pairs of the motor; This represents the initial phase of the nth harmonic; Indicates the harmonic order.

[0104] The actual air gap magnetic flux density can be considered as being composed of an average magnetic field, a fundamental magnetic field, and multiple higher-order spatial harmonics. The fundamental magnetic field mainly determines the average electromagnetic torque output by the motor, while the higher-order spatial harmonics mainly affect the cogging torque, electromagnetic torque pulsation, and motor vibration noise.

[0105] To obtain the parameters of each harmonic order, the harmonic coefficients can be calculated using the Fourier expansion principle: Average magnetic flux density This reflects the average level of the entire air gap magnetic field and can be used to evaluate the overall magnetic flux capability provided by the permanent magnet. It is an important indicator for analyzing the rationality of the motor's magnetic circuit. In the Fourier expansion, this term, as a zero-order component, does not participate in the formation of cogging torque, but determines the baseline value of the entire magnetic field. Its expression is: (1) Cosine harmonic coefficient This represents the amplitude of the nth spatial harmonic in the cosine direction. By calculating the cosine coefficients of different orders, the composition of each harmonic in the air gap magnetic flux density can be obtained, providing a basis for analyzing the source of magnetic field harmonics. Its expression is: (2) Sine harmonic coefficient It reflects the distribution of spatial harmonics of each order in the sinusoidal direction, and together with the cosine coefficient, determines the actual amplitude and spatial location of the corresponding harmonic. Its expression is: (3) Harmonic amplitude The strength of the nth-order magnetic field harmonic is a crucial parameter for evaluating the quality of a motor's magnetic field. Based on the cosine and sine coefficients, the amplitude of the nth-order spatial harmonic can be further calculated. (4) To determine the initial position of each spatial harmonic in the circumferential direction, the phase angle is calculated based on the cosine and sine coefficients: (5) The phase of a harmonic determines the spatial distribution of each order of spatial harmonics. When an unequal stator tooth width structure is used, the phase of each order of spatial harmonics changes due to the varying degrees of circumferential offset of each stator tooth. By rationally designing the stator tooth offset angle, phase cancellation can occur between some higher-order spatial harmonics, thereby reducing cogging torque and electromagnetic torque pulsation.

[0106] In the subsequent analysis, the effect of the stator unequal tooth width structure on the air gap magnetic field distribution was evaluated by comparing the changes in the amplitude and phase of each harmonic before and after optimization, and a tooth cogging torque analytical model was further established.

[0107] This invention employs Fourier expansion to analyze the air gap magnetic flux density and combines it with finite element analysis to evaluate the optimization effect. In other embodiments, analytical methods, magnetic circuit methods, equivalent magnetic network methods, finite difference methods, boundary element methods, or other electromagnetic field numerical analysis methods can also be used to calculate electromagnetic performance. As long as structural optimization design and performance evaluation can be achieved, they all fall under the scope of this invention.

[0108] (2) Establishment of analytical model for cogging torque: To quantitatively analyze the influence of the stator's unequal tooth width structure on the cogging torque, a mathematical model of the cogging torque was further established after completing the Fourier expansion of the air gap magnetic flux density.

[0109] Cogging torque refers to the periodic electromagnetic torque generated in a permanent magnet synchronous motor (PMSM) when the windings are not energized, due to the interaction between the magnetic field of the permanent magnet and the stator cogging structure. Its generation is caused by the continuous periodic change in air gap permeability as the rotor rotates, resulting in a constant change in the energy stored in the air gap magnetic field with the rotor position. According to the principle of energy conservation, this change in stored energy generates additional electromagnetic torque, i.e., cogging torque. Therefore, this invention uses the electromagnetic energy method to establish an analytical model for cogging torque.

[0110] Assume the energy stored in the air gap magnetic field of the motor is According to electromagnetic field theory, the magnetic field energy density per unit volume is... .

[0111] Therefore, the magnetic field energy storage in the entire air gap region can be expressed as: (6) in The mechanical angle represents the energy stored in the air gap magnetic field (J). Indicates the rotor mechanical angle (rad); Indicates the air gap magnetic flux density (T); Indicates the permeability of free space; This indicates the volume of the air gap region.

[0112] Due to the continuous rotation of the rotor, the air gap magnetic flux density The energy stored in the air gap magnetic field changes continuously with the mechanical angle, and therefore also changes accordingly. According to the principle of virtual work, the cogging torque can be expressed as the first derivative of the energy stored in the air gap magnetic field with respect to the mechanical angle: (7) in This represents the cogging torque (N·m).

[0113] The expression for the air gap magnetic flux density obtained by expanding the aforementioned Fourier transform is as follows: (8) And the air gap permeability caused by the stator slots: (9) Substituting into the air gap magnetic field expression: (10) The actual air gap magnetic flux density of the optimized motor can then be obtained. Substituting this into the expression for magnetic field energy storage and differentiating with respect to the mechanical angle, the analytical expression for cogging torque can be obtained: (11) Where represents the magnitude of the i-th order cogging torque; Indicates the number of stator slots; This represents the phase angle corresponding to the i-th spatial harmonic; This indicates the harmonic order used in the analysis.

[0114] In traditional constant-tooth-width motors, the stator teeth are uniformly distributed along the circumference, and each order of spatial harmonics has a fixed phase. Therefore, the cogging torques of each order are superimposed, resulting in a large total cogging torque. This invention employs a stator with unequal tooth width, causing different degrees of circumferential offset in each stator tooth, thus changing the phase of each order of harmonics in the air gap permeability function. Let the offset angle of the m-th stator tooth be . .

[0115] The optimized air gap permeability function can then be expressed as: (12) It can be seen that the stator tooth offset angle directly changes the phase of each order of magnetic permeability harmonics, so that the cogging torque generated by different tooth slots is no longer synchronously superimposed, but rather phase cancellation occurs to a certain extent.

[0116] As the stator tooth offset angle changes, the amplitude and phase of the cogging torque of each order also change, thus altering the total cogging torque. When the offset angle meets the optimal condition, the main cogging torque harmonics of each order can achieve the maximum phase cancellation effect, thereby minimizing the motor cogging torque.

[0117] Therefore, this invention uses the stator tooth offset angle as an optimization variable to study the variation law of tooth cogging torque corresponding to different offset angles in subsequent finite element analysis, and finally determines the optimal stator tooth offset angle.

[0118] In this embodiment of the invention, the stator tooth offset angle within a fixed range is used for optimization. In other embodiments, different offset angle ranges, different scanning step sizes, or different optimization algorithms (such as parameter scanning method, genetic algorithm, particle swarm optimization, response surface optimization method, etc.) can be used to determine the optimal offset parameters according to the number of motor slots, number of poles, and operating conditions. The optimization method is not limited to this embodiment.

[0119] This invention accurately extracts the harmonic characteristics of the air gap magnetic field through Fourier expansion, establishes the theoretical derivation logic of cogging torque by combining the electromagnetic energy method and the principle of virtual work, and then introduces the tooth offset modulation permeability function to complete the analytical model construction, providing complete theoretical support for stator tooth offset optimization. It gets rid of the limitations of traditional pure simulation calculation, can quickly predict the cogging torque suppression effect at different offset angles, and significantly shorten the stator structure optimization cycle.

[0120] In one exemplary embodiment, based on the above embodiments, please refer to... Figure 6 The embodiments of this application involve performing finite element analysis calculations on a cogging torque analytical model based on multiple pre-set offset angle schemes to obtain an optimized stator, including the following steps: S601 performs finite element simulation calculations on each offset angle scheme to obtain multiple sets of electromagnetic performance simulation data.

[0121] In this embodiment, all parameters such as motor size, permanent magnet, winding, air gap, and operating conditions are fixed during the simulation process, and only different stator tooth offset angle schemes are replaced; the rotor is driven to complete the simulation of a complete mechanical cycle rotation, and all electromagnetic performance simulation data such as cogging torque, torque pulsation, air gap magnetic flux density distribution, and magnetic field harmonics corresponding to each scheme are extracted respectively.

[0122] S602, based on the simulation data of various electromagnetic performances, calculates the cogging torque attenuation rate and processes the target offset angle to obtain the optimized stator.

[0123] Among them, the tooth cogging torque reduction rate is an index that quantitatively evaluates the effect of the sub-tooth offset structure in suppressing tooth cogging torque. It is obtained by calculating the peak-to-peak value of tooth cogging torque before and after optimization.

[0124] The target offset angle refers to the stator tooth offset angle that achieves the optimal reduction of cogging torque while also taking into account the overall electromagnetic performance of the motor.

[0125] In this embodiment, the cogging torque peak-to-peak value of a traditional constant tooth width stator is used as a benchmark, and the cogging torque reduction rate corresponding to each offset angle scheme is calculated. By comprehensively comparing multiple indicators such as reduction rate, average torque, and torque pulsation, the target offset angle with the best overall performance is selected, and the stator tooth structure design is completed according to the offset angle to obtain the optimized stator.

[0126] Specifically, to ensure the comparability of the analysis results, the following parameters were kept constant throughout the optimization process: motor dimensions, stator slot dimensions, rotor structural dimensions, permanent magnet dimensions and magnetization direction, winding structure and number of turns, air gap length, power supply parameters, and operating conditions. Only the circumferential offset angle of the stator teeth was changed to study the effect of different offset angles on the cogging torque.

[0127] This invention sets up multiple offset angle schemes for finite element calculation, using stator tooth offset angles as an example. As an optimization variable, a scanning analysis is performed within a preset offset range based on the motor slot-pole fit relationship. The stator tooth offset angle range is set to 0-2° and gradually increased in fixed steps of 0.2°. The first option is a traditional equal tooth width structure, while the other options correspond to different degrees of unequal tooth width structures.

[0128] For each offset angle scheme, the drive rotor rotates continuously within one complete mechanical cycle, and the cogging torque data corresponding to different rotation angle positions are extracted to plot the cogging torque curve. Simultaneously, the average electromagnetic torque, torque pulsation, air gap magnetic flux density distribution, magnetic field harmonics, and local magnetic saturation are calculated for each scheme, and the impact of the stator tooth offset angle on the overall electromagnetic performance of the motor is analyzed.

[0129] To quantitatively evaluate the optimization effect, the peak-to-peak value of cogging torque is used as the evaluation index. Let the peak-to-peak value of cogging torque of the traditional constant tooth width motor before optimization be... The peak-to-peak value of the cogging torque for the optimized offset angle scheme is: The cogging torque attenuation rate is defined as: (13) in This indicates the rate of reduction in cogging torque (%). This represents the peak-to-peak value of the cogging torque (N·m) of a conventional constant tooth width motor. This represents the peak-to-peak value of the cogging torque (N·m) for the corresponding offset angle scheme.

[0130] This invention obtains complete electromagnetic data through batch finite element simulation with multiple offset angles and achieves quantitative evaluation by relying on the cogging torque reduction rate. It can objectively select the optimal stator tooth offset parameters, which can significantly reduce cogging torque and suppress low-speed torque fluctuations while taking into account the motor output torque and running stability, thereby improving the control torque gyroscope attitude control accuracy.

[0131] In one exemplary embodiment, based on the above embodiments, please refer to... Figure 7 The embodiments of this application involve magnetic circuit optimization processing of a basic rotor by opening holes in the rotor yoke, and the process of obtaining an optimized rotor includes the following steps: S701, the yoke region of the basic rotor is processed with an opening structure layout to obtain an initial rotor structure with yoke openings.

[0132] In this embodiment, the rotor permanent magnet size, pole shape, and overall outer diameter are kept unchanged. Openings are symmetrically arranged in the yoke region between adjacent permanent magnets. Various opening shape schemes are designed to generate multiple initial rotor geometries with yoke openings.

[0133] S702 performs electromagnetic simulation on initial rotor structures with different opening sizes and positions to obtain multiple sets of rotor magnetic circuit performance data.

[0134] Among them, rotor magnetic circuit performance data refers to parameters such as rotor yoke magnetic flux density, air gap magnetic flux density, average electromagnetic torque, torque pulsation, and core saturation obtained from simulation.

[0135] In this embodiment, all other structural parameters such as the motor stator, windings, and air gap are fixed, and only the opening size and the radial and circumferential positions of the opening are adjusted. Finite element electromagnetic simulations are carried out to collect magnetic circuit performance data such as yoke magnetic flux density, output torque, torque pulsation, and iron loss for each rotor.

[0136] S703, based on the magnetic circuit performance data of each group of rotors, performs comparative analysis and processing of magnetic circuit characteristics and electromagnetic performance, selects target opening parameters, and obtains the rotor with optimized magnetic circuit.

[0137] Among them, the target opening parameters refer to the optimal combination of opening shape, size and position, taking into account both electromagnetic performance and rotor mechanical strength.

[0138] In this embodiment, the uniformity of magnetic flux distribution, local saturation, average torque, and torque pulsation of each scheme are compared. At the same time, the mechanical strength and dynamic balance performance of the rotor are checked, and the opening size and position with the best comprehensive performance are selected as the target opening parameters. The rotor model is reconstructed according to these parameters to obtain the rotor with optimized magnetic circuit.

[0139] The specific execution steps of this application embodiment are as follows: First, the rotor yoke opening was optimized. To further improve the output torque of the low-speed frame motor for the control torque gyroscope, the rotor yoke structure was optimized after the stator unequal tooth width structure was optimized. Traditional permanent magnet synchronous motors typically use a complete iron core structure for the rotor yoke, with the magnetic flux mainly closed along the yoke. When the magnetic flux distribution in the yoke is uneven or there is local magnetic saturation, it leads to a reduction in magnetic circuit utilization, limiting further increases in the motor's electromagnetic torque.

[0140] Next, the magnetic circuit optimization and stator-rotor co-optimization methods for the rotor yoke openings are implemented. This invention sets weight-reducing openings in the rotor yoke, changing the magnetic circuit distribution in the rotor yoke to make the magnetic flux more uniform, reduce local magnetic saturation, and improve the utilization rate of permanent magnet magnetic energy, thereby increasing the average electromagnetic torque of the motor.

[0141] While keeping the overall dimensions of the motor, stator structure, permanent magnet dimensions, and winding parameters unchanged, an opening model is established in the rotor yoke. The openings are located in the rotor yoke region between adjacent permanent magnets, and the overall rotor structure is kept symmetrical to avoid a decrease in rotor dynamic balance performance due to uneven mass distribution.

[0142] Models of different opening shapes, including circular, elliptical, oblong, waist-shaped, and rectangular rounded corner openings, were established. Under the condition of the same opening area, finite element analysis was performed on different opening shapes to calculate the air gap magnetic flux density distribution, average electromagnetic torque, and torque pulsation under different schemes, and the influence of different opening shapes on the electromagnetic performance of the motor was compared.

[0143] After determining the opening shape, the influence of the opening size on motor performance was further studied. Based on the optimized opening shape, parameter models for different opening sizes were established. Keeping the opening center position and rotor pole structure unchanged, multiple size schemes were formed by changing the opening diameter (or the size of the major and minor shafts). The finite element method was used to calculate the air gap magnetic flux density distribution, rotor yoke magnetic flux density distribution, average electromagnetic torque, torque pulsation, permanent magnet operating point, and iron loss variation law for each scheme.

[0144] As the aperture size gradually increases, the magnetic reluctance of the rotor yoke gradually increases, the magnetic flux is redistributed, and the local magnetic saturation phenomenon is alleviated. The average electromagnetic torque of the motor shows a trend of first increasing and then decreasing. When the aperture size is too small, the improvement effect on the magnetic circuit is limited; when the aperture size is too large, the effective magnetic conductive area of ​​the rotor yoke is significantly reduced, the magnetic flux carrying capacity decreases, leading to increased leakage flux and a decrease in motor output torque. Therefore, by optimizing the dimensional parameters, the optimal aperture size that balances average torque, torque ripple, and mechanical strength is determined.

[0145] Further research was conducted on the impact of the number of openings on motor performance. While maintaining a relatively consistent total opening area, single-hole, double-hole, and multi-hole structural models were established for each pole, ensuring that all openings were symmetrically arranged along the magnetic pole centerline to maintain rotor mass balance. The magnetic flux distribution characteristics under different opening numbers were analyzed, and the influence of magnetic circuit dispersion on air gap magnetic field harmonics, electromagnetic torque, and torque pulsation was investigated.

[0146] Finite element analysis results show that when the number of openings is small, the magnetic flux regulation capability is limited. As the number of openings increases, the magnetic flux distribution tends to be more uniform, local magnetic saturation is further reduced, and the average electromagnetic torque is improved. However, when the number of openings is too large, the continuous magnetic conduction path of the rotor yoke is excessively weakened, magnetic flux leakage increases, and the rotor mechanical strength decreases, which is not conducive to the long-term reliable operation of the motor. Therefore, the optimal number of openings is determined by considering both electromagnetic performance and structural reliability.

[0147] After obtaining the optimal opening shape, size, and number, the opening positions are further optimized. Keeping the opening size and number constant, the distance between the opening and the permanent magnet, as well as the radial position of the opening, are adjusted to establish multiple position parameter models. The rotor magnetic flux density distribution, magnetic field harmonic content, and electromagnetic torque variation patterns under different position conditions are analyzed to determine the optimal opening position.

[0148] By optimizing the location, the opening is positioned near the region of high magnetic flux density in the rotor yoke. This ensures that the yoke has sufficient magnetic conductivity while effectively reducing local magnetic saturation, improving magnetic flux utilization, and making the air gap magnetic flux density waveform closer to a sinusoidal distribution. This further improves the average electromagnetic torque and reduces torque pulsation.

[0149] In this embodiment of the invention, the rotor yoke weight reduction opening improves the magnetic circuit distribution. In other embodiments, the opening can be circular, elliptical, oblong, waist-shaped, rectangular with rounded corners, polygonal, arc-shaped, or other regular or irregular hole shapes; the number of openings can be single hole, multiple holes, or a combination of holes; the position of the opening can be adjusted radially, circumferentially, or simultaneously radially and circumferentially; the size of each opening can also be the same or different. As long as it can improve the rotor magnetic flux distribution, reduce local magnetic saturation, and improve the magnetic energy utilization rate of the permanent magnet, it falls within the protection scope of this invention.

[0150] In addition to openings in the yoke, the magnetic circuit distribution of the rotor yoke can also be adjusted by methods such as yoke thinning, local grooves, magnetic flux adjustment slots, non-uniform yoke thickness structures, magnetic barrier structures, or local magnetic conduction structure optimization, so as to improve the magnetic density distribution and increase the average electromagnetic torque.

[0151] Finally, the stator unequal tooth width optimization structure and the rotor yoke opening optimization structure were jointly designed. A joint optimization finite element model was established while maintaining the motor's external dimensions, permanent magnet dimensions, winding parameters, and control strategy. The performance indicators of the motor before and after joint optimization, including air gap magnetic flux density, back EMF, electromagnetic torque, torque ripple, iron loss, copper loss, and efficiency, were comprehensively analyzed to evaluate the synergistic effect of the two optimization measures.

[0152] The joint optimization results show that the stator unequal tooth width structure improves the stator side magnetic field distribution and increases the effective utilization rate of the windings; the rotor yoke opening optimization improves the rotor magnetic circuit distribution and increases the permanent magnet magnetic energy utilization rate. The combined effect of these two factors further improves the average electromagnetic torque of the motor and reduces torque ripple. This enables the low-speed frame motor of the control torque gyroscope to have higher torque output capability, better torque stability, and higher operating efficiency under low-speed, high-torque conditions, providing more stable and reliable drive performance for the control torque gyroscope attitude control system.

[0153] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0154] Based on the same inventive concept, this application also provides a control torque gyroscope low-speed frame motor optimization device for implementing the aforementioned control torque gyroscope low-speed frame motor optimization method. The solution provided by this device is similar to the implementation described in the above method. Therefore, the specific limitations in one or more control torque gyroscope low-speed frame motor optimization device embodiments provided below can be found in the limitations of the control torque gyroscope low-speed frame motor optimization method described above, and will not be repeated here.

[0155] In one embodiment, such as Figure 8 As shown, a low-speed frame motor optimization device 800 for controlling torque gyroscopes is provided, comprising: Modeling module 801 is used to construct a basic motor finite element model based on the overall performance index of the control torque gyroscope and the main parameters of the motor; the basic motor finite element model includes a basic stator and a basic rotor. The stator optimization module 802 is used to optimize the cogging torque of the basic stator with unequal tooth width to obtain the optimized stator. The rotor optimization module 803 is used to perform magnetic circuit optimization processing on the yoke opening of the basic rotor to obtain the optimized rotor. The collaborative optimization module 804 is used to perform collaborative optimization on the optimized stator and the optimized rotor to obtain the target motor model.

[0156] Each module in the aforementioned low-speed frame motor optimization device for the control torque gyroscope can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0157] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 9 As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The communication interface allows for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements an optimization method for a low-speed frame motor of a torque gyroscope. The display unit forms a visually visible image and can be a screen, projection device, or virtual reality imaging device. The screen can be an LCD or e-ink display. The input device can be a touch layer covering the screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0158] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0159] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps: A basic motor finite element model is constructed based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor; the basic motor finite element model includes the basic stator and the basic rotor. The cogging torque of the basic stator is optimized by performing cogging torque optimization on the unequal tooth width to obtain the optimized stator; The magnetic circuit of the basic rotor is optimized by opening holes in the rotor yoke to obtain the optimized rotor; The optimized stator and the optimized rotor are then subjected to collaborative optimization to obtain the target motor model.

[0160] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor: A basic motor finite element model is constructed based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor; the basic motor finite element model includes the basic stator and the basic rotor. The cogging torque of the basic stator is optimized by performing cogging torque optimization on the unequal tooth width to obtain the optimized stator; The magnetic circuit of the basic rotor is optimized by opening holes in the rotor yoke to obtain the optimized rotor; The optimized stator and the optimized rotor are then subjected to collaborative optimization to obtain the target motor model.

[0161] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps: A basic motor finite element model is constructed based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor; the basic motor finite element model includes the basic stator and the basic rotor. The cogging torque of the basic stator is optimized by performing cogging torque optimization on the unequal tooth width to obtain the optimized stator; The magnetic circuit of the basic rotor is optimized by opening holes in the rotor yoke to obtain the optimized rotor; The optimized stator and the optimized rotor are then subjected to collaborative optimization to obtain the target motor model.

[0162] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0163] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0164] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0165] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for optimizing the low-speed frame motor of a control torque gyroscope, characterized in that, The method includes: A basic motor finite element model is constructed based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor; the basic motor finite element model includes a basic stator and a basic rotor; The base stator is subjected to cogging torque optimization processing with unequal tooth width to obtain an optimized stator; The magnetic circuit of the basic rotor is optimized by performing a yoke opening process to obtain an optimized rotor; The optimized stator and the optimized rotor are then subjected to collaborative optimization to obtain the target motor model.

2. The method according to claim 1, characterized in that, The construction of a basic motor finite element model based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor includes: Based on the overall performance indicators of the control torque gyroscope, electromagnetic design processing is performed on the frame motor to obtain the motor design parameters; Based on the control torque output of the control torque gyroscope and the transmission relationship between the frame drive mechanism, the motor design parameters are matched and modeled to obtain the motor electromagnetic model; Two-dimensional and three-dimensional finite element simulation analysis and model assignment processing are performed on the electromagnetic model of the motor to obtain the basic finite element model of the motor for optimization calculation.

3. The method according to claim 1, characterized in that, The optimization process of cogging torque on the basic stator with unequal tooth widths results in an optimized stator comprising: The stator teeth of the basic stator are grouped and offset to obtain a stator structure with unequal tooth width; Based on the motor air gap magnetic flux density corresponding to the unequal tooth width stator structure, an analytical model of tooth cogging torque is established. The cogging torque analytical model is subjected to finite element analysis and calculation based on multiple pre-set offset angle schemes to obtain the optimized stator.

4. The method according to claim 3, characterized in that, The establishment of the analytical model for cogging torque based on the air gap magnetic flux density of the motor corresponding to the unequal tooth width stator structure includes: The air gap magnetic flux density of the motor with the unequal tooth width stator structure is subjected to Fourier expansion to obtain the amplitude and phase parameters of each order of spatial harmonics. Based on the amplitude and phase parameters of each order of spatial harmonics, the correspondence between the energy stored in the air gap magnetic field and the cogging torque is solved using the electromagnetic energy method and the principle of virtual work. An analytical model for cogging torque is constructed based on the air gap permeability function modulated by stator tooth offset, which can characterize the influence of stator tooth offset angle on cogging torque.

5. The method according to claim 3, characterized in that, The optimized stator obtained by performing finite element analysis on the cogging torque analytical model based on multiple pre-set offset angle schemes includes: Finite element simulation calculations were performed on each of the aforementioned offset angle schemes to obtain multiple sets of electromagnetic performance simulation data. Based on the electromagnetic performance simulation data, the cogging torque attenuation rate is calculated and the target offset angle is selected to obtain the optimized stator.

6. The method according to claim 1, characterized in that, The magnetic circuit optimization process of the basic rotor by opening holes in the rotor yoke results in an optimized rotor, comprising: The yoke region of the basic rotor is processed with an open structure layout to obtain an initial rotor structure with yoke openings. Electromagnetic simulation was performed on the initial rotor structures with different opening sizes and positions to obtain multiple sets of rotor magnetic circuit performance data; Based on the rotor magnetic circuit performance data of each group, the magnetic circuit characteristics and electromagnetic performance are compared and analyzed, the target opening parameters are selected, and the rotor with optimized magnetic circuit is obtained.

7. A device for optimizing the low-speed frame motor of a control torque gyroscope, characterized in that, The device includes: The modeling module is used to construct a basic motor finite element model based on the overall performance indicators of the control torque gyroscope and the main parameters of the motor; the basic motor finite element model includes a basic stator and a basic rotor. The stator optimization module is used to perform cogging torque optimization processing on the basic stator with unequal tooth width to obtain an optimized stator; The rotor optimization module is used to perform magnetic circuit optimization processing on the yoke opening of the basic rotor to obtain an optimized rotor; The collaborative optimization module is used to perform collaborative optimization processing on the optimized stator and the optimized rotor to obtain the target motor model.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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