Thermal control method and device for improving performance of lunar rail laser corner reflector

Abstract

The invention discloses a thermal control method and device for improving the performance of a lunar orbit laser corner reflector, and belongs to the technical field of space flight and aviation. The method comprises the following steps: in a non-test stage, analyzing illuminated and thermal environment data of the corner reflector in a lunar orbit, and designing heat dissipation and heat insulation measures, so that the corner reflector is in a low-temperature storage stage; in the test preparation stage, heating belts are started for preheating, temperature measurement data of all areas of the corner reflector are collected, and the duty ratio of all the heating belts is independently adjusted in combination with a novel PID temperature control algorithm and an external heat flow prediction model; in the test process, the heating belt is started, all areas of the corner reflector are monitored and adjusted in real time, and when temperature deviation occurs, the duty ratio of the heating belt is adjusted through a novel PID temperature control algorithm and an external heat flow prediction model; and after the test is completed, the corner reflector enters the low-temperature storage stage again. According to the invention, high precision and high reliability of the laser corner reflector on the lunar orbit can be ensured, and the success probability of laser ranging on the lunar orbit spacecraft corner reflector by the ground is improved.

Description

Technical Field

[0001] The present invention belongs to the field of aerospace technology, and in particular, relates to a thermal control method and device for improving the performance of a lunar orbit laser corner reflector. Background Art

[0002] Currently, the application of laser corner reflectors in lunar orbit faces a series of challenges, especially in terms of thermal deformation accuracy control. Laser corner reflectors are high-precision distance measuring devices. Laser corner reflectors are usually installed on the outside of satellites. During the operation of satellites in orbit, they are affected by factors such as direct sunlight, infrared radiation and sunlight reflection, and their operating temperature changes accordingly. The measurement accuracy of the laser corner reflector optical system and the trihedral angle are relatively sensitive to temperature. The success of laser ranging is mainly affected by the measurement error of the laser corner reflector. In order to ensure the measurement accuracy of the laser corner reflector optical system, higher and higher thermal control index requirements are put forward for the laser corner reflector; in existing technologies, the design of single large-aperture laser corner reflectors is to improve the accuracy of lunar laser ranging, but the increase in the aperture of the laser corner reflector also brings about the problem of thermal control.

[0003] The extreme temperature differences in the lunar space environment and the uneven illumination of laser corner reflectors cause local deformation of the laser corner reflector material due to thermal expansion and contraction, affecting ranging accuracy. Current thermal control designs generally adopt a passive-first, active-secondary thermal control scheme, due to the relatively low thermal requirements for laser corner reflectors. This involves a multi-layer cladding and active temperature control design on the mounting surface. This thermal control scheme can generally meet the requirements for low-Earth orbit laser corner reflectors. However, for laser corner reflectors and their assemblies with higher requirements for lunar orbit, the temperature gradient cannot be precisely controlled. Therefore, using only the above-mentioned methods to meet measurement requirements is difficult to achieve.

[0004] For the thermal control of the laser angle reflector assembly of satellite components, its temperature rise requirements can generally be met by means of heater power compensation. How to avoid excessive temperature gradients and keep the temperature of each position of the angle reflector consistent so as not to cause optical performance degradation due to thermal deformation due to local temperature unevenness is the key and difficulty of thermal control design. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a thermal control method and device for improving the performance of lunar orbit laser corner reflectors, which are used to solve the problem of reduced accuracy of laser corner reflectors (hereinafter referred to as corner reflectors) in lunar orbit due to thermal deformation, ensure the thermal stability and thermal gradient of the corner reflectors in lunar orbit, so that the overall temperature and temperature gradient of the corner reflectors are within the required index range, and improve the optical performance of lunar orbit satellite-borne laser corner reflectors in the complex space thermal environment.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A thermal control method for improving the performance of a lunar orbit laser corner reflector comprises the following steps:

[0008] Step 1: During the non-test phase, analyze the illumination and thermal environment data of the corner reflector in lunar orbit and design heat dissipation or insulation measures to keep the corner reflector in a low-temperature storage stage.

[0009] Step 2, test preparation phase: start the heating belt preheating, collect temperature data of each area of ​​the corner reflector, combine the PID temperature control algorithm and the external heat flow prediction model, and independently adjust the duty cycle of each heating belt to ensure that the temperature gradient meets the requirements;

[0010] Step 3: During the test: Start the heating belt and conduct real-time monitoring and adjustment of each area of ​​the corner reflector. When the temperature deviates, adjust the duty cycle of the heating belt through the PID temperature control algorithm and the external heat flow prediction model.

[0011] Step 4: After the test is completed, the satellite attitude maneuvers back to the conventional solar panel sun orientation mode, and the corner reflector re-enters the low-temperature storage stage.

[0012] Furthermore, in step 1, the "low temperature" refers to a temperature lower than the operating temperature of the corner reflector, which is intended to facilitate precise temperature control by heating during the test phase and avoid excessively high temperatures during the storage phase that may lead to difficulty in temperature control later.

[0013] Furthermore, each area of ​​the corner reflector includes the corner reflector body and its lens seat, spacer, back cover, and mounting structure area, and each area is provided with an independent heating belt and a PID controller connected to the heating belt.

[0014] Furthermore, in step 2, the external heat flow prediction model adjusts the duty cycle of the heating zone in advance at the position where the external heat flow is predicted to change significantly.

[0015] Furthermore, in step 2 or step 3, the novel PID control algorithm calculates and adjusts the power adjustment amount of the heating belt according to the following formula: ,in, They represent the proportional part, integral part, differential part adjustment amount and external heat flow correction amount of the PID controller respectively.

[0016] Furthermore, the proportional part adjustment amount , Indicates the proportional coefficient, which determines the controller's response to the current deviation; the integral part = , Indicates the integral coefficient, which is used to eliminate the steady-state error of the system; the differential part = , Indicates the differential coefficient, which is used to predict the change trend of the deviation; external heat flow compensation part It represents the compensation term for the temperature fluctuation caused by the external heat flow during the satellite's attitude maneuver; e represents the deviation between the expected corner reflector operating temperature and the current temperature of the corner reflector obtained by real-time monitoring of the temperature sensor.

[0017] Furthermore, the outer side of the corner reflector is covered with a thermal control multilayer and an OSR reflective surface, a sunshade is installed on the front side of the corner reflector, and the corner reflector is made of solid glass.

[0018] Furthermore, the heating belt includes a plurality of heating elements, and each heating belt is of a special-shaped design and fits perfectly with the surface of the corner reflector.

[0019] Furthermore, the edges of the heating zones are shaped like saw teeth, and the serrated edges of adjacent heating zones are completely aligned.

[0020] In another aspect, the present invention provides a thermal control device for improving the performance of a lunar orbit laser corner reflector, which is applied to the aforementioned thermal control method for improving the performance of a lunar orbit laser corner reflector. The device comprises:

[0021] A temperature measurement module, used to divide the corner reflector into multiple temperature measurement areas, each temperature measurement area includes a temperature sensor;

[0022] An active temperature control module is used to independently and actively control multiple temperature measurement areas. Each temperature measurement area includes an independently controlled special-shaped heating belt, which is connected to a PID controller. It is used to achieve precise temperature control of each area by adjusting the duty cycle of the heating belt based on the data from the temperature measurement module and the external heat flow prediction model;

[0023] The passive temperature control module is used to set up thermal control multiple layers, OSR reflective surface and sunshade on the outside of the corner reflector to achieve heat insulation and reflect solar radiation.

[0024] The control module is used to combine the satellite orbit attitude data and the external heat flux prediction model to dynamically adjust the external heat flux correction term of the PID controller and coordinate the active and passive temperature control modules to ensure that the overall temperature and temperature gradient of the corner reflector meet the index requirements.

[0025] The beneficial effects of the present invention are:

[0026] This invention divides the corner reflector into multiple temperature-controlled zones, utilizes heating bands for real-time, precise, novel PID temperature control, introduces an external heat flux compensation mechanism, and incorporates a special-shaped, serrated-edge heating plate design to ensure a smooth temperature transition between zones. This minimizes temperature differences between adjacent zones, helping to prevent thermal deformation caused by temperature unevenness and improving laser reflection accuracy, a crucial requirement for high-precision measurement missions such as Earth-Moon laser ranging.

[0027] The low-temperature design during the non-testing phase ensures that the corner reflector's storage temperature remains below the operating temperature. This prevents the corner reflector from partially exceeding the operating temperature during the testing phase, preventing rapid cooling and heat dissipation. This can lead to significant temperature gradients and thermal deformation, impacting performance. Conventional loads are not intentionally temperature-controlled below the operating temperature during the non-testing phase. Without active cooling, there is a risk that the ambient temperature during operation will be too high and unable to be lowered to the operating range.

[0028] During the testing phase, a new PID algorithm was used to quickly and accurately adjust the temperature to the operating temperature and maintain stability. A stable operating temperature maintains the optical performance and reflective characteristics of the laser corner reflector, improving the accuracy and reliability of ranging. The new PID temperature control algorithm introduces an external heat flux compensation term, combining the satellite's orbit and attitude, as well as the influence of internal heating units, to predict and adjust external heat flux changes. This allows for precise control of the corner reflector's temperature and temperature uniformity, ensuring on-orbit optical performance.

[0029] In addition to the laser incident surface, the sides and bottom (trihedral angles) of the angular invertor are evenly coated with flexible electric heating sheets. The heating sheets are shaped in a non-uniform manner and conform to the surface of the angular invertor. The edges of the heating sheets are serrated, and the serrated edges of adjacent heating sheets are perfectly aligned. This ensures that the temperature control areas covered by different heating sheets will experience a smooth transition between target temperatures, preventing excessive temperature gradients. The remaining structural components outside the angular invertor also implement active temperature control measures as needed, following this approach.

[0030] The sunshade, OSR reflective surface, and thermal control multilayer material in the thermal control system work together to create an optimized thermal environment for the corner reflector. The sunshade protects the interior of the reflector from direct sunlight, the OSR reflective surface reflects solar radiation, reducing the amount of heat absorbed by the reflector, and the thermal control multilayer material provides both insulation and heat preservation. This combination enables the reflector to maintain optimal operation in the complex lunar orbit thermal environment. For example, during non-test periods, the reflector can be kept at a relatively low temperature, facilitating accurate and uniform temperature control when heating to operating temperature. This avoids the weight, power consumption, and complexity associated with the introduction of active cooling modules. Even under high temperatures, such as those under direct sunlight, the internal temperature of the reflector remains elevated due to excessive heat input, ensuring proper operation and preventing performance degradation due to overheating, effectively improving operational performance.

[0031] The use of heating tape with a PID control algorithm specifically tailored to the corner reflector enables efficient temperature regulation. Based on real-time temperature data and external heat flux compensation, the PID controller rapidly calculates and adjusts the heating tape's power, ensuring the corner reflector reaches operating temperature quickly. Furthermore, throughout the entire operating process, timely adjustments are made to temperature fluctuations, ensuring the required temperature remains constant. Compared to traditional temperature regulation methods, this approach is more precise and efficient, reducing adjustment time and thus improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The following is a flow chart of a thermal control method for improving the performance of a lunar orbit laser corner reflector;

[0033] Figure 2 The main body shape and basic working principle of the corner reflector of the present invention;

[0034] Figure 3 This is a structural diagram of the corner reflector body and the heating plate of the present invention;

[0035] Figure 4 This is the distribution structure diagram of the heating plate. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to the accompanying drawings and examples.

[0037] like Figure 1 FIG. 1 is a flow chart of a thermal control method for improving the performance of a lunar orbit laser corner reflector according to the present invention, which specifically includes the following steps:

[0038] Step 1: During the non-test phase, by analyzing the illumination and thermal environment data of the corner reflector in lunar orbit, design heat dissipation or thermal insulation measures to keep the corner reflector in a low-temperature storage phase, where the low temperature means below the operating temperature.

[0039] Step 2: Prepare for the test phase: Figure 2 The figure below shows the main body shape and basic working principle of the corner reflector in the present invention. The corner reflector is made of solid glass, and its bottom is composed of three mutually perpendicular reflective surfaces. Its appearance resembles a solid corner, which is called a "trihedral angle." Its basic working principle is: when an electromagnetic wave or light wave is incident on the corner reflector, it is reflected in sequence by the three reflective surfaces. The reflected wave will return in a direction parallel to the incident wave, thereby achieving efficient reflection of the incident wave. It has important applications in fields such as laser ranging. The "trihedral angle" formed by the three reflective surfaces is the core area for precise temperature control.

[0040] The heating zones are preheated. The temperature control module collects temperature measurements from each zone and implements a new PID temperature control system, enabling independent preheating of each zone. Simultaneously, by pre-programming the upcoming maneuver instructions and using the model's predicted external heat flux, the new PID algorithm is adjusted and modified. The duty cycle of the heating zones is adjusted in advance where significant changes in external heat flux are predicted. This ensures that the temperature and temperature gradient of each temperature-controlled zone meet the required standards.

[0041] Step 3: During the test: Start the heating belt and monitor and adjust the temperature of the corner reflector in real time. When the temperature deviates, adjust the duty cycle of the heating belt through the PID controller (introducing the external heat flow model correction).

[0042] Step 4: After the test is completed, the satellite attitude maneuvers back to the conventional solar panel sun orientation mode, and the corner reflector re-enters the low-temperature storage stage.

[0043] Among them, in step 1, the purpose of lowering the temperature of the corner reflector during the storage stage is to facilitate the subsequent use of the heating belt PID temperature control to accurately increase the temperature of each area of ​​the corner reflector and maintain the temperature uniformity without excessive gradient changes. Otherwise, if the corner reflector itself is affected by sunlight or the heat consumption of a high-power single unit on the satellite, causing the temperature of a single area of ​​the corner reflector to be too high, it will be difficult to compensate by the heating belt itself in other areas. If additional active heat dissipation or cooling functions are added, the cost and complexity of the satellite will be greatly increased. Therefore, designing a low-temperature thermal environment for the corner reflector during the storage stage is a method that is easy to operate, saves energy, and facilitates the control of temperature gradients.

[0044] In steps 2 and 3, a new PID temperature control algorithm was employed, introducing an external heat flux correction term into the traditional PID temperature control algorithm. Because the corner reflectors are mounted outside the cabin in an insulated manner, the external heat flux of lunar-orbiting satellites primarily comes from sunlight. As the satellite's attitude adjusts, the angle and position of the illumination change, causing changes in the temperature of the corner reflectors, which can affect temperature control accuracy. A model for external heat flux variation is established based on the satellite's orbit and attitude, allowing for preemptive compensation and adjustments in the algorithmic control.

[0045] The PID controller is used to adjust the power output of the heating belt based on the temperature feedback signal. By setting the parameters of the PID controller, a PWM signal is output to control the operation of the heater, achieving rapid response and stable control of the diagonal temperature. Conventional PID parameters include proportional, integral, and differential. The present invention introduces an external heat flow correction term into the PID parameter control items.

[0046] The new PID control algorithm calculates and adjusts the power regulation of the heating belt according to the following formula ,in, Represents the proportional part, integral part, differential part adjustment amount, and external heat flow correction amount of the PID controller. By adjusting the duty cycle of the heating belt, the temperature is controlled within the set range. , Represents the proportional coefficient, which determines the controller's response to the current deviation; the integral part = , Indicates the integral coefficient, which is used to eliminate the steady-state error of the system; the differential part = , Indicates the differential coefficient, which is used to predict the change trend of the deviation; external heat flow compensation part represents the compensation term for temperature fluctuations caused by external heat flux during satellite attitude maneuvers; e represents the deviation between the desired corner reflector operating temperature and the current corner reflector temperature as measured by the real-time temperature sensor. For example, for a specific heating zone in a specific area, the conventional PID algorithm calculates a 50% duty cycle to maintain the target temperature. However, the satellite is about to maneuver into direct sunlight in this area, and the accessory mounting surface in this area is about to power on during a period of high power consumption. At this time, the computer pre-calculates and adjusts the duty cycle based on the external heat flux variation model to compensate for the impending external heat flux change, thereby further reducing the main body temperature fluctuation.

[0047] Based on the above method, the present invention also provides a thermal control device for improving the performance of a lunar orbit laser corner reflector, comprising:

[0048] The temperature measurement module divides the corner reflector into multiple temperature measurement areas, accurately measuring the temperature of the laser corner reflector body, its mirror mount, spacer, back cover, etc., to determine the temperature gradient distribution of the entire corner reflector. The selection of the sensor takes into account measurement accuracy, response time, and stability in extreme environments;

[0049] The active temperature control module divides the corner reflector into multiple temperature control zones through the distribution of different heating zones. A new PID algorithm is used to precisely control the temperature of the corner reflector body, its mirror mount, spacer, back cover, and other areas. This module is used to precisely control the temperature of the corner reflector. Each temperature control zone is equipped with a heating zone and a PID controller connected to the heating zone. This controller is used to precisely control the temperature of each temperature control zone in real time, ensuring that the overall temperature and temperature gradient of the corner reflector are within the required index range. The temperature control zones correspond one-to-one with the temperature measurement zones.

[0050] Passive Temperature Control Module: The corner reflector is wrapped with a thermal control multilayer, a multilayer insulation material used for spacecraft thermal control. It consists of multiple layers of materials, such as aluminized polyester film, separated by spacers. Its principle is to effectively block heat conduction and radiation through multi-layer reflection and low thermal conductivity, thereby maintaining a stable temperature environment for spacecraft internal equipment. The thermal control multilayer is coated with an OSR reflective surface to reduce the impact of extreme temperatures such as direct sunlight and the cold background of deep space on the corner reflector.

[0051] Furthermore, the system also includes a control unit, which combines the temperature measurement module's data with the satellite's orbital position and attitude-dependent external heat flow model to control the temperature settings of the active and passive temperature control modules and adjust the electric heating belt's output duty cycle to ensure that the corner reflector's overall temperature and temperature gradient remain within the required specification range. The control unit's functions are centrally calculated by the onboard integrated electronics unit.

[0052] Furthermore, the thermal control multilayer of the passive temperature control module includes a multilayer material coating for insulating and heat-retaining the corner reflector. The multilayer material is carefully selected based on thermophysical properties such as thermal conductivity, heat capacity and emissivity to achieve effective temperature control of the corner reflector.

[0053] Furthermore, the passive temperature control module wraps a circle of OSR reflective sheet around the outside of the corner reflector's thermal control layer. During solar exposure, the OSR heat dissipation surface can effectively reflect solar radiation, significantly reducing the amount of heat absorbed by the corner reflector. For example, under direct sunlight, if there is no OSR heat dissipation surface, the surface temperature of the corner reflector may rise rapidly due to the absorption of solar radiation; with the OSR heat dissipation surface, the increase in its surface temperature will be greatly reduced, possibly by tens of degrees Celsius compared to when there is no OSR heat dissipation surface. The specific value depends on factors such as the intensity of solar radiation, exposure time, and the reflectivity of the OSR heat dissipation surface. In low-temperature designs during the non-test phase, the OSR heat dissipation surface can help maintain the low-temperature storage state of the corner reflector. During the test phase, it also helps to stabilize the temperature of each temperature-controlled area to prevent local overheating.

[0054] Furthermore, the laser corner reflector is made of solid material, and each temperature control area is the corner reflector body. In addition to the side and bottom surfaces other than the incident surface, multiple flexible electric heating sheets are distributed in the temperature control area. The heating belt includes multiple heating elements, and each heating belt corresponds to one of the temperature control areas of the corner reflector, and the shape of the heating belt is a special-shaped design. It fits perfectly with the surface of the corner reflector. The edge of the electric heating sheet is a serrated shape, and the serrated edges between adjacent heating sheets can be completely matched. Ensure that the temperature control areas covered by different heating sheets have a smooth temperature transition when the target temperature is inconsistent, and there will be no excessive temperature gradient. The remaining structural parts outside the main body of the corner reflector also implement active temperature control measures according to the above method as needed. Such as Figure 3 As shown in the figure, the temperature measurement point structure diagram of the corner reflector body and the heating plate of the present invention, wherein different heating plates on the body surface are distinguished by different filling patterns (preferably, the corner reflector body has a total of six heating plates and temperature measurement points, which are symmetrically distributed, as shown in FIG. Figure 4 As shown in the figure), the edges of the heating plate adopt a sawtooth distribution to ensure the consistency of the temperature gradient.

[0055] Example:

[0056] Prior to the laser corner reflector test (non-test phase), the corner reflector's thermal environment was designed to be low-temperature based on the illumination and thermal environment analysis during its lunar orbit. Excess heat was dissipated through the heat dissipation surface, keeping the overall storage temperature of the corner reflector lower than the operating temperature and ensuring a uniform temperature gradient. The temperature control and measurement modules monitored the temperature in real time, activating heating if the temperature threshold was exceeded.

[0057] Preparatory test phase: Before ranging begins, the satellite's attitude is adjusted to ensure that the laser corner reflector receives solar radiation evenly, reducing the risk of local overheating. Furthermore, comprehensive consideration is required regarding the satellite antenna's visibility relative to the ground tracking station, the star sensor's visibility, and the solar array's visibility relative to the Sun. Dynamic model simulations ensure that satellite telemetry signals are consistently received during ranging, that attitude sensors remain in normal operation, and that sufficient energy is available. To meet these constraints, the satellite's attitude can be adjusted as necessary at other angles, while maintaining the corner reflector's position relative to the Earth.

[0058] After determining the satellite's expected attitude adjustment during the test, the satellite service computer will perform illumination analysis and calculations based on the attitude conditions to obtain the illumination conditions of the corner reflector during the test, that is, the changes in external heat flux. This will be used as the external heat flux correction item in the temperature control algorithm and output to the temperature control module in real time.

[0059] 1.5 hours before the start of the ranging, the PID controller's precise temperature control mode is activated. Based on real-time temperature data and external heat flux changes calculated by the satellite's computer, the power output of the heating belt and the PMW duty cycle are adjusted in real time to compensate for external heat flux changes. This ensures that the corner reflector temperature is precisely controlled within the set range.

[0060] During the test, ensure that the temperature gradient at each location is maintained within 0.1°C and the average temperature is maintained at 20±0.1°C.

[0061] During the testing phase, the heating belts in the thermal control system were activated, and PID temperature control was employed to ensure consistent temperature gradient regulation. The passive thermal control system for the laser corner reflector unit features a design where the corner reflector mounting surface and body are coated with multiple layers of materials and OSR film, along with a sunshade. These materials include, but are not limited to, highly reflective metal foil, thermally insulating ceramic layers, low-emissivity coatings, and highly reflective OSR material. The selection of these materials and the number of layers are designed to minimize the impact of the external thermal environment on the corner reflector's temperature. The sunshade protects against direct sunlight while minimizing the effects of stray light.

[0062] Temperature sensors, such as thermocouples, thermistors, or temperature sensors, are installed at various locations on the corner reflector. These sensors are evenly distributed across predefined temperature control zones to ensure comprehensive monitoring of the temperature distribution. Heating strips are installed at critical locations on the corner reflector, such as the edges and areas with large temperature gradients. These strips are managed by a PID controller, which adjusts their output in real time based on data from the temperature measurement module. Six heating strips and temperature measurement points are installed on the corner reflector body, and several heating strips and temperature measurement points are installed on the corner reflector shell and structural components. The measurement points and heating strips are positioned one-to-one. The corner reflector is oriented toward the Earth's laser observation station. Traditional thermal control methods focus only on localized temperature measurement points and fail to capture overall temperature gradient changes. Traditional PID temperature control algorithms fail to account for changes in external heat flux caused by attitude changes and compensate for these changes in advance. When the corner reflector is exposed to sunlight for extended periods of time, localized overheating and overheating can occur, leading to large temperature gradients and the risk of thermal deformation. These can cause subtle deformations in the corner reflector, degrading its on-orbit optical performance. However, based on the above measures of the present invention, the on-orbit performance of the laser corner reflector will be maintained at an optimal state, thereby increasing the probability of successful lunar orbit satellite-to-ground ranging.

[0063] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thermal control method for improving the performance of a lunar orbit laser corner reflector, characterized in that: The following steps are involved: Step 1: During the non-test phase, analyze the illumination and thermal environment data of the corner reflector in lunar orbit and design heat dissipation or insulation measures to keep the corner reflector in a low-temperature storage stage. Step 2, test preparation phase: Start the heating belt to preheat, collect temperature data from each area of ​​the corner reflector, combine the new PID temperature control algorithm and external heat flow prediction model, and independently adjust the duty cycle of each heating belt to ensure that the temperature gradient meets the requirements; Step 3: During the test: Start the heating belt and conduct real-time monitoring and adjustment of each area of ​​the corner reflector. When the temperature deviates, adjust the duty cycle of the heating belt using the new PID temperature control algorithm and external heat flow prediction model. Step 4: After the test is completed, the satellite attitude maneuvers back to the conventional solar panel orientation attitude, and the corner reflector re-enters the low-temperature storage stage.

2. The thermal control method for improving the performance of a lunar orbit laser corner reflector according to claim 1, characterized in that: In step 1, the low temperature means about 5-10° C. lower than the operating temperature.

3. The thermal control method for improving the performance of a lunar orbit laser corner reflector according to claim 1, characterized in that: Each area of ​​the corner reflector includes a corner reflector body and its mirror base, a spacer, a back cover, and an installation structure area. Each area is provided with an independent heating belt and a PID controller connected to the heating belt.

4. The thermal control method for improving the performance of a lunar orbit laser corner reflector according to claim 1, characterized in that: In step 2, the external heat flow prediction model adjusts the duty cycle of the heating zone in advance at the location where the external heat flow is predicted to change significantly.

5. The thermal control method for improving the performance of a lunar orbit laser corner reflector according to claim 4, characterized in that: In step 2 or step 3, the novel PID control algorithm calculates and adjusts the power adjustment amount of the heating belt according to the following formula: ,in, They represent the proportional part, integral part, differential part adjustment amount and external heat flow correction amount of the PID controller respectively.

6. The thermal control method for improving the performance of a lunar orbit laser corner reflector according to claim 5, characterized in that: The proportional part adjustment amount , Represents the proportional coefficient, which determines the controller's response to the current deviation; Integral part = , Indicates the integral coefficient, which is used to eliminate the steady-state error of the system; the differential part = , Indicates the differential coefficient, which is used to predict the change trend of the deviation; external heat flow compensation part It represents the compensation term for the temperature fluctuation caused by the external heat flow during the satellite's attitude maneuver; e represents the deviation between the expected corner reflector operating temperature and the current temperature of the corner reflector obtained by real-time monitoring of the temperature sensor.

7. The thermal control method for improving the performance of a lunar orbit laser corner reflector according to claim 3, characterized in that: The outer side of the corner reflector is covered with a thermal control multilayer and an OSR reflective surface, and a light shield is installed on the front side of the corner reflector. The corner reflector is made of solid glass.

8. The thermal control method for improving the performance of a lunar orbit laser corner reflector according to claim 3, characterized in that: The heating belt includes a plurality of heating elements, and each heating belt is of a special-shaped design and is completely fitted with the surface of the corner reflector.

9. The thermal control method for improving the performance of a lunar orbit laser corner reflector according to claim 8, characterized in that: The edges of the heating zones are in a sawtooth shape, and the sawtooth edges of adjacent heating zones completely match each other.

10. A thermal control device for improving the performance of a lunar orbit laser corner reflector, applied to a thermal control method for improving the performance of a lunar orbit laser corner reflector according to any one of claims 1 to 9, characterized in that: The device comprises: A temperature measurement module, used to divide the corner reflector into multiple temperature measurement areas, each temperature measurement area includes a temperature sensor; An active temperature control module is used to independently and actively control multiple temperature measurement areas. Each temperature measurement area includes an independently controlled special-shaped heating belt, which is connected to a PID controller. It is used to achieve precise temperature control of each area by adjusting the duty cycle of the heating belt based on the data from the temperature measurement module and the external heat flow prediction model; Passive temperature control module, which is used to set up thermal control multilayer, OSR reflective surface and sunshade on the outside of the corner reflector to achieve heat insulation and reflect solar radiation; The control module is used to combine the satellite orbit attitude data and the external heat flux prediction model to dynamically adjust the external heat flux correction term of the PID controller and coordinate the active and passive temperature control modules to ensure that the overall temperature and temperature gradient of the corner reflector meet the index requirements.

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