A generalized momentum wheel

Abstract

This invention discloses a universal momentum wheel, comprising a bearing assembly, a photoelectric encoder assembly, a housing assembly, a wheel assembly, a through-wall connector, a controller assembly, a motor assembly, a bracket, and a shielding cover. The overall layout of the universal momentum wheel adopts an electromechanical integrated, compartmentalized design: the high-speed rotating components, such as the wheel assembly, bearing assembly, and motor assembly, are housed within a vacuum chamber formed by the housing assembly, while the controller assembly is placed within a non-vacuum chamber formed by the housing assembly. Power and communication between the components in the vacuum chamber and the components in the non-vacuum chamber are achieved through a sealed through-wall connector. By replacing the wheel with different moments of inertia, the universal momentum wheel of this invention can output different angular momentum. The universal momentum wheel provided by this invention has promising application prospects.

Description

Technical Field

[0001] This invention belongs to the field of aerospace technology, specifically relating to a universal momentum wheel. Background Technology

[0002] The momentum wheel is an important actuator in the satellite's on-orbit attitude control system. It receives control commands from the onboard computer and generates a reaction torque by accelerating or decelerating the momentum wheel body through a drive motor. This torque exchanges angular momentum with the satellite body, thereby achieving the purpose of controlling the satellite's attitude.

[0003] With the rapid development of my country's aerospace industry, the demand for high-performance, high-reliability, long-life, and rapid development of core components such as momentum wheels is becoming increasingly strong. However, existing momentum wheel products are heavily customized for specific models and missions. While this approach can address specific model requirements, it also directly leads to numerous problems such as a wide variety of product specifications, low production volume, complex technical specifications, poor applicability, long development cycles, and high production costs.

[0004] Furthermore, with the increasing demands of on-orbit applications, existing single-mode momentum wheels can no longer meet the requirements of control systems. In the past, the approach of designing momentum wheel products with different functions to meet the requirements of multiple on-orbit modes also resulted in too many satellite-related products and complex supporting solutions.

[0005] In addition, existing momentum wheels have many other problems, such as photoelectric encoder speed measurement schemes being susceptible to failure due to the combined effects of space ionization radiation and displacement damage; Hall effect speed measurement schemes lack accuracy and cannot perform high-precision control at low speeds; under rapid maneuvering conditions, heat is generated quickly and heat dissipation is difficult; the debugging process of controller components can cause frequent changes in the vacuum level of the shaft system environment, affecting the performance of the shaft system, etc. Summary of the Invention

[0006] To address the problems of existing momentum wheel products, such as their significant customization features and lack of versatility, the difficulty of high-speed debugging of electromechanical integrated flywheels and the impact of frequent air extraction on product reliability, and the large space occupied by split flywheels and the difficulty of overall layout, this invention provides a universal momentum wheel.

[0007] The universal momentum wheel provided by this invention comprises:

[0008] A housing assembly includes an outer shell and a compartmental plate; the outer shell encloses a compartment, and the compartmental plate is disposed in the compartment, dividing the compartment into a vacuum compartment and a non-vacuum compartment;

[0009] A bearing assembly, disposed within the vacuum chamber, is used to drive the wheel to rotate; the bearing assembly includes a bushing and a support platform, the support platform being disposed on the outer edge of the bushing;

[0010] A motor assembly, mounted on the support platform, is used to drive the bearing assembly, causing the bushing to rotate;

[0011] A wheel assembly comprising a plurality of wheels with different moments of inertia; the wheels are disposed on the bushing;

[0012] An optical encoder assembly is mounted on the support platform and is used to measure the rotational speed of the bearing assembly and transmit the rotational speed information to the controller assembly.

[0013] A controller assembly is located in the non-vacuum chamber; the controller assembly adjusts the motor assembly and controls the rotational speed of the bearing assembly based on the received rotational speed information.

[0014] Optionally, the universal momentum wheel also includes a through-wall connector;

[0015] The through-wall connector is sealed through the compartment plate and enables power supply and communication between the vacuum chamber and the non-vacuum chamber.

[0016] Optionally, the universal momentum wheel also includes a bracket;

[0017] The bracket is located in the vacuum chamber and is mounted on the compartment plate;

[0018] The bearing assembly is mounted on the bracket.

[0019] Optionally, the wheel body can be detached from the bushing;

[0020] The universal momentum wheel can output different angular momentum by replacing the wheel body with one of different moments of inertia.

[0021] Optionally, a shielding cover is provided on the slit seat of the photoelectric encoder assembly to provide protection for the back and sides of the photoelectric encoder;

[0022] The shielding cover is made of high-density stainless steel.

[0023] Optionally, the outer shell of the non-vacuum chamber is equipped with several mechanical and electrical interfaces for docking with the entire satellite.

[0024] Compared with the prior art, the universal momentum wheel provided by the present invention has the following advantages or beneficial effects:

[0025] The generalized momentum wheel structure adopts an integrated electromechanical layout with compartmentalized placement. The motor assembly, housing assembly, controller assembly, and bearing assembly are modularly designed and universal, with each component relatively independent and no cross-coupling during production. High-speed rotating components such as the wheel assembly, bearing assembly, and motor assembly are placed in a welded, sealed vacuum chamber, maintaining a long-term vacuum state and reducing the performance impact of repeated vacuuming. The controller assembly is located in the non-vacuum chamber of the housing assembly, facilitating controller debugging and testing. Power and communication between components in the vacuum chamber and those in the non-vacuum chamber are achieved via sealed through-wall connectors. By replacing the wheel with different moments of inertia, angular momentum outputs of 10Nms to 50Nms (covering the flywheel's angular momentum requirements) can be achieved, and other components are universal. Once all components are assembled, simple assembly is possible, improving production capacity and reliability.

[0026] This invention's control scheme employs a multi-mode coexistence approach, including torque mode, speed mode, and coasting mode, enabling rapid switching between modes to meet the diverse needs of different users. Simultaneously, these modes can be coupled for joint control, achieving high-precision torque output and improving product performance. By adding a shielding cover to the photoelectric encoder, its protection against space particles is enhanced, extending its on-orbit lifespan. Furthermore, improvements to the motor design and optimization algorithms improve the accuracy of Hall effect speed measurement, enabling it to replace the photoelectric encoder, reducing reliance on it and enhancing the speed measurement and control reliability of the flywheel product. In addition, an automatic switching method between reverse braking and energy-efficient braking is adopted; that is, energy-efficient braking is used at high speeds, while direct switching to reverse braking occurs at low speeds. This significantly reduces the heat generated during flywheel deceleration, alleviating on-orbit heat dissipation pressure and effectively improving product performance. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the universal momentum wheel described in this invention;

[0028] Figure 2 A schematic diagram of a shielding cover installed on the photoelectric encoder assembly;

[0029] Figure 3 This is a schematic diagram of the energy consumption control circuit of the universal momentum wheel described in this invention;

[0030] Figure 4 This is a schematic diagram of the high-precision torque closed-loop control principle of the universal momentum wheel described in this invention. Detailed Implementation

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

[0032] It should be noted that, in this document, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising..." or "including..." does not exclude the presence of additional elements in the process, method, article, or terminal device that includes said element.

[0033] It should be noted that the accompanying drawings are all in a very simplified form and use non-precise ratios, and are only used to facilitate and clearly illustrate the purpose of one embodiment of the present invention.

[0034] Figure 1 This is a schematic diagram of the structure of the universal momentum wheel described in this invention; Figure 2 A schematic diagram of a shielding cover installed on the photoelectric encoder assembly; Figure 3 This is a schematic diagram of the energy consumption control circuit of the universal momentum wheel described in this invention; Figure 4 This is a schematic diagram of the high-precision torque closed-loop control principle of the universal momentum wheel described in this invention.

[0035] See also Figure 1-4The universal momentum wheel provided by this invention includes a bearing assembly 100, a photoelectric encoder assembly 200, a housing assembly, a wheel assembly, a through-wall connector 500, a controller assembly 600, a motor assembly 700, a bracket 800, and a shield 900. The housing assembly includes an outer shell 300 and a compartment plate 310; the outer shell 300 encloses a chamber, and the compartment plate 310 is disposed within the chamber, dividing it into a vacuum chamber 10 and a non-vacuum chamber 20; the compartment plate 310 has a groove structure in the middle for mounting the motor assembly 100. The motor assembly 100 is disposed within the vacuum chamber 10 and drives the wheel 400 to rotate. The bearing assembly 100 includes a bushing 110 and a support platform 120, the support platform 120 being disposed on the outer edge of the bushing 110. The wheel assembly includes a plurality of wheels 400 with different moments of inertia, the wheels 400 being disposed on the bushing 110. The photoelectric encoder assembly 200 is disposed on the support platform 120 and is used to measure the rotational speed of the bearing assembly 100 and transmit the rotational speed information to the controller assembly 600. The controller assembly 600 is disposed inside the non-vacuum chamber 20; the controller assembly 600 adjusts the relevant parameters of the motor assembly according to the received rotational speed information, thereby controlling the rotational speed of the bearing assembly. The through-wall connector 500 passes through the compartment plate 310 in a sealed manner, and the components inside the vacuum chamber and the components inside the non-vacuum chamber are powered and communicated through the sealed through-wall connector. The bracket 800 is located inside the vacuum chamber 10 and is disposed on the compartment plate 310, and the bearing assembly 100 is mounted on the bracket 800. The wheel body 400 is detachable from the bushing 120; the universal momentum wheel can output different angular momentum by replacing the wheel body 400 with different moments of inertia. A shielding cover 900, made of high-density stainless steel, is added to the slit mount of the photoelectric encoder assembly 200 to provide protection for the back and sides of the photoelectric encoder. Several mechanical and electrical interfaces (not shown in the figure) are installed on the outer shell of the non-vacuum chamber 20 for docking with the entire satellite.

[0036] like Figure 1As shown, the universal momentum wheel structure adopts an integrated design with compartmentalized placement, mainly composed of motor components, bearing components, wheel components, housing components, photoelectric encoder components (optional), and controller components. The main structural parts, such as rotating components, are placed in a vacuum chamber, while the controller circuit is placed in a non-vacuum chamber. This completely separates the manufacturing and testing processes of the flywheel structure from those of the control circuit. The final assembly process uses simple plug-in and screw fixing methods, thereby achieving multi-line parallel manufacturing and rapid assembly capabilities, significantly reducing the product manufacturing cycle. Simultaneously, the compartmentalized structure ensures both electromechanical integration and facilitates the debugging and testing of the control circuit without altering the vacuum environment of the shaft system. This improves testing efficiency and protects the shaft system from frequent changes in the vacuum environment, enhancing product reliability.

[0037] like Figure 2 As shown, on the one hand, a shielding cover is added to the slit mount of the photoelectric encoder assembly. The shielding cover is made of high-density stainless steel and is fixed on the slit mount at the receiving plate mounting position, providing protection for the back and sides of the photoelectric encoder. Combined with ground radiation resistance test data, the added shielding cover can extend the life of the photoelectric encoder to more than 15 years. On the other hand, by increasing the number of motor pole pairs and increasing the number of Hall effect sensors, the number of pulse signals that can be collected per revolution is significantly increased. At the same time, the combined "M method" + "T method" speed measurement is adopted to ensure that the momentum wheel can achieve pure Hall speed measurement ≤1 rpm across the entire speed range, greatly improving product reliability.

[0038] like Figure 3As shown, this product employs a control method that switches between regenerative braking and reverse braking. At high speeds, regenerative braking is used, utilizing the motor's back EMF to maintain torque output; the onboard power supply is only used for the control circuit. At low speeds, since the back EMF cannot guarantee torque output, reverse braking control mode is activated. Only a small amount of kinetic energy is consumed through the regenerative resistors, significantly reducing flywheel energy loss. In traditional reverse braking mode, both upper and lower bridge arms are simultaneously conducting, allowing power to be supplied to the motor. Due to the large back EMF at high speeds, the voltage at the power supply end rises, triggering the pump-up suppression circuit S7 and activating regenerative resistors Rm1 and Rm2. In regenerative braking mode, upper bridge arm S1, S2, and S3 are all off, and current circulates only within the lower bridge arm. High-precision torque output is ensured by controlling the on / off state of the MOSFETs in the lower bridge arm through a speed closed-loop control. When the MOSFET is turned on, taking S4 as an example, current flows through D5 and D6. At this time, part of the flywheel's kinetic energy is consumed through the three-phase resistors Ra, Rb, and Rc, and the other part is converted into inductive electromagnetic energy to maintain the flywheel's rotational speed. When the MOSFET is turned off, current flows through D1, D5, and D6, charging capacitors C1 and C2. When the back EMF is too high, the pump-up suppression circuit S7 is activated, and the kinetic energy is consumed through energy-dissipating resistors Rm1 and Rm2. Through the closed-loop speed control method, the magnitude of current and braking electromagnetic torque can be flexibly controlled, while energy feedback is achieved, reducing product energy consumption. The segmented speed braking method not only solves the risk of device burnout during high-speed braking of the actuator but also reduces flywheel power consumption, greatly improving the reliability of the actuator.

[0039] like Figure 4 As shown, the speed increment value within each control cycle is calculated based on the current torque command value. The theoretical speed value is then calculated based on this speed increment value, thus achieving the purpose of introducing a speed closed loop to ensure torque output accuracy. Introducing only a speed closed loop would result in an uncontrollable large current when the flywheel initially responds to the torque command. To eliminate the impact of this current on the satellite attitude, a speed closed loop is not introduced during the first control cycle of the flywheel's torque command response; instead, traditional current closed-loop control is used. Speed ​​closed-loop control is added at the beginning of the second control cycle to eliminate large current interference and ensure high-precision torque output.

[0040] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A universal momentum wheel, characterized in that, Include: A housing assembly includes an outer shell and a compartmental plate; the outer shell encloses a compartment, and the compartmental plate is disposed in the compartment, dividing the compartment into a vacuum compartment and a non-vacuum compartment; A bearing assembly, disposed within the vacuum chamber, is used to drive the wheel to rotate; the bearing assembly includes a bushing and a support platform, the support platform being disposed on the outer edge of the bushing; A motor assembly is mounted on the support platform and is used to drive the bearing assembly to rotate the bushing; a wheel assembly includes a plurality of wheels with different moments of inertia; the wheels are mounted on the bushing and are detachable from the bushing. An optical encoder assembly is mounted on the support platform and is used to measure the rotational speed of the bearing assembly and transmit the rotational speed information to the controller assembly. A shielding cover is provided on the slit seat of the optical encoder assembly to provide protection for the back and sides of the optical encoder. A bracket is located in the vacuum chamber and is disposed on the compartment plate, and the bearing assembly is mounted on the bracket; The controller assembly is located in the non-vacuum chamber; The controller component adjusts the motor component and controls the speed of the bearing component based on the received speed information.

2. The universal momentum wheel as described in claim 1, characterized in that, The universal momentum wheel also includes a through-wall connector; The through-wall connector is sealed through the compartment plate and enables power supply and communication between the vacuum chamber and the non-vacuum chamber.

3. The universal momentum wheel as described in claim 1, characterized in that, The universal momentum wheel can output different angular momentum by replacing the wheel body with one of different moments of inertia.

4. The universal momentum wheel as described in claim 1, characterized in that, The shielding cover is made of high-density stainless steel.

5. The universal momentum wheel as described in claim 1, characterized in that, The outer shell of the non-vacuum chamber is equipped with several mechanical and electrical interfaces for docking with the entire satellite.

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