A method for controlling the temperature of a blackbody that can be adjusted in real time in orbit and a blackbody temperature control system

Abstract

The present invention relates to the technical field of on-orbit blackbody temperature control, and specifically provides an on-orbit real-time adjustable blackbody temperature control method and a blackbody temperature control system. The temperature control method includes: setting a temperature overshoot threshold and obtaining an auxiliary temperature for temperature control according to the desired temperature of the blackbody; collecting the blackbody temperature at a fixed period, adjusting the temperature control method in stages. In the first stage, a full-power temperature control method is adopted to minimize the temperature difference between the real-time temperature and the desired temperature of the blackbody at the fastest rate; in the second stage, a fixed duty cycle is used for temperature control; in the third stage, according to the temperature difference between the real-time temperature and the desired temperature of the blackbody, the duty cycle of the temperature control signal is dynamically adjusted, so that the real-time temperature of the blackbody gradually approaches the desired temperature of the blackbody, avoiding a too large temperature overshoot amplitude, resulting in large fluctuations in the real-time temperature of the blackbody at the desired temperature point and making it difficult to stably control the temperature. Through the staged fine temperature control strategy, the present invention effectively avoids temperature overshoot and realizes fast and fine temperature control from coarse to fine.

Description

Technical Field

[0001] The present invention belongs to the technical field of on-orbit blackbody temperature control, and particularly relates to a method for on-orbit real-time adjustable blackbody temperature control and a blackbody temperature control system. Background Technique

[0002] In the field of modern space remote sensing technology, on-orbit calibration of infrared remote sensing cameras is an important link to ensure their measurement accuracy and data reliability. Currently, during the on-orbit calibration process of infrared remote sensing cameras, on-board blackbodies are used for temperature control, and the accuracy of blackbody temperature control directly affects the accuracy of calibration and correction. The traditional blackbody temperature control method mainly maintains the blackbody temperature by continuously outputting a fixed power. However, the traditional blackbody temperature control method still has some deficiencies in practical applications, such as low temperature control accuracy, complex control process, large calculation amount, etc., and it is difficult to meet the requirements of high-precision calibration.

[0003] The deficiencies of the existing blackbody temperature control methods in terms of temperature control accuracy, temperature overshoot control, calculation amount, and on-orbit real-time adjustability limit the accuracy and reliability of on-orbit calibration of infrared remote sensing cameras. Therefore, there is an urgent need for a new method for on-orbit real-time adjustable precise blackbody temperature control to overcome the defects of the existing technology and meet the requirements of high-precision blackbody temperature control in modern space remote sensing technology. Summary of the Invention

[0004] In view of this, the present invention aims to provide a method for on-orbit real-time adjustable blackbody temperature control. From the perspective of actual engineering applications, through a three-stage sub-interval temperature control strategy and combined with FPGA real-time processing, while reducing the calculation amount, the temperature control strategy from coarse to fine realizes fast and refined temperature control, and solves the problems of insufficient accuracy, large temperature overshoot, slow response speed, etc. in the process of on-orbit blackbody temperature control of the existing technology.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows:

[0006] On the one hand, the present invention provides a method for on-orbit real-time adjustable blackbody temperature control, including:

[0007] Setting a temperature overshoot threshold , and calculating the auxiliary temperature for temperature control according to the expected blackbody temperature as:

[0008] ;

[0009] Wherein, is the expected blackbody temperature, that is, the target temperature that the expected blackbody finally reaches; is the auxiliary temperature during the temperature control process;

[0010] Obtaining the initial blackbody temperature , and calculating the temperature control target difference as:

[0011] ;

[0012] Obtain the real-time temperature of the blackbody at a cycle, and set the temperature control method in stages according to the real-time temperature of the blackbody as follows:

[0013] Within the interval, where , the temperature control signal for each cycle is always at a high level;

[0014] Within the interval, where , the duty cycle of the temperature control signal for each cycle is , the high-level output time of the temperature control signal is , and the remaining time is at a low level;

[0015] Within the interval, dynamically adjust the duty cycle of the temperature control signal for each cycle to make the real-time temperature of the blackbody approach the desired temperature of the blackbody.

[0016] Preferably, the value of the temperature overshoot threshold is 3.

[0017] Preferably, the value of the cycle is 512 ms.

[0018] Preferably, within the interval, the duty cycle of the temperature control signal for each cycle is .

[0019] Preferably, within the interval, the duty cycle of the temperature control signal for each cycle is , the high-level output time of the temperature control signal is , and the remaining time is at a low level, so that the real-time temperature of the blackbody approaches the desired temperature of the blackbody.

[0020] Preferably, use FPGA to implement setting the temperature control method in stages according to the real-time temperature of the blackbody.

[0021] Preferably, the temperature control method is heating up or cooling down.

[0022] Preferably, use a temperature sensor to obtain the real-time temperature of the blackbody, and the temperature sampling period of the temperature sensor is .

[0023] On the other hand, the present invention provides a blackbody temperature control system, including: controlling the temperature of the blackbody by using a real-time adjustable blackbody temperature control method in orbit.

[0024] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0025] Through a phased fine temperature control strategy, the present invention effectively avoids temperature overshoot and realizes rapid and fine temperature control from coarse to fine. In the first stage, full-power temperature control is adopted to quickly narrow the temperature difference. In the second stage, the temperature change rate is reduced by fixed duty cycle control. In the third stage, the duty cycle is dynamically adjusted according to the real-time temperature difference to gradually approach the target temperature, thereby ensuring that the blackbody temperature can be stabilized near the target point, achieving the purpose of high-precision temperature control. By means of the auxiliary temperature and the temperature overshoot threshold, the temperature fluctuation near the target point is avoided, ensuring the smoothness of the temperature control process.

[0026] In addition, the temperature control method of the present invention has a small amount of calculation and can be efficiently processed by FPGA. In an environment with limited resources such as in-orbit temperature control, the present invention does not require complex computing resources and a large amount of storage space, can effectively reduce the hardware cost and complexity of the system, and improve the reliability and maintainability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0028] Figure 1 is a flowchart of a real-time adjustable blackbody temperature control method in orbit according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many details are described to enable a better understanding of the present invention. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the present invention are not shown or described in the specification, which is to avoid the core part of the present invention being overwhelmed by excessive description. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0030] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other to form various embodiments. At the same time, the steps or actions in the method description can also be adjusted in the order that is obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for clearly describing a certain embodiment and do not mean that they are the necessary order, unless it is stated that a certain order must be followed.

[0031] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0032] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0033] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0034] Please refer to Figure 1 , in an embodiment of the present invention, a method for controlling the temperature of a blackbody that can be adjusted in real time in orbit is provided. Through a phased temperature control strategy, it can effectively avoid temperature overshoot, improve the temperature control stability, and ensure the accuracy of on-orbit calibration and correction of an infrared remote sensing camera. The method for controlling the temperature of a blackbody in the embodiment of the present invention is applicable to devices that require precise blackbody temperature control, such as infrared remote sensing satellites and space probes operating in orbit. The method for controlling the temperature of a blackbody specifically includes:

[0035] S1: First, determine the key parameters in the temperature control process, mainly including the desired temperature of the blackbody , the temperature overshoot threshold and the temperature control proportionality coefficient in the second stage, that is, the fixed duty cycle of the temperature control signal. The method for controlling the temperature of a blackbody in the embodiment of the present invention is usually carried out in the environment of on-board software or a controller. Therefore, during the setting process of the key temperature control parameters, the desired temperature of the blackbody , the temperature overshoot threshold and the duty cycle of the temperature control signal in the second stage are input into the on-board software or the controller. In the embodiment of the present invention, the desired temperature of the blackbody is set , 560H is the hexadecimal representation of the desired temperature of the blackbody, and the temperature data in the following text are all represented in decimal.

[0036] Set the temperature overshoot threshold , the temperature overshoot threshold is an incremental value used to adjust the temperature target point finally reached by the temperature control. Utilizing the characteristic of temperature overshoot, the real-time temperature of the blackbody during the temperature control process can rebound to the set desired temperature of the blackbody. According to the temperature overshoot threshold and the desired temperature of the blackbody , the auxiliary temperature in the temperature control process can be calculated as:

[0037] .

[0038] Among them, is the temperature that the black body is expected to reach in the process of temperature control, and In the process of temperature control, the temperature of the black body can be stabilized at A nearby auxiliary value.

[0039] Temperature overshoot threshold and auxiliary temperature The design mainly utilizes the temperature overshoot characteristic. If the target of the temperature control process is directly set as , the temperature control system may exceed the target value too much due to overshoot, and then rebound, which will cause large temperature fluctuations near the target point, making it difficult to achieve stable temperature control. The temperature control is stopped immediately after the black body is turned off, and the black body temperature naturally drops slightly, causing the black body temperature to never reach the expected temperature. , and set the temperature control target to , the temperature overshoot characteristic can be cleverly utilized. When the real-time temperature of the black body reaches At the moment of temperature overshoot, the natural fall will cause the real-time temperature of the black body to rebound to close to This design allows the temperature control system to naturally return to the set blackbody desired temperature after the temperature overshoots, thereby achieving more stable and precise temperature control and preventing the real-time temperature from fluctuating around the desired temperature and failing to stabilize.

[0040] The temperature control goal is to make the real-time temperature of the black body gradually approach the set black body expected temperature by heating or cooling. The real-time temperature of the black body is measured by a sensor, and the sensor temperature measurement cycle is In the embodiment of the present invention, The value is 512ms, that is, the real-time temperature of the black body is obtained every 512ms, and the duty cycle of the temperature control signal is adjusted. The duty cycle of the temperature control signal reflects the time ratio of the high level and the low level. The high level indicates that the temperature control is in progress, and the low level indicates that the temperature control is not in progress. For example, during the heating process, the high level indicates that the heating is carried out during this period of time, and the low level indicates that the heating is not carried out. During this process, the temperature of the black body will naturally drop. Due to the temperature control detection cycle The time is short, so the temperature naturally drops very little, so it can be considered that the duty cycle of the temperature control signal is the power level of the temperature control. The system response speed and stability need to be considered comprehensively to set the cycle. Setting the width too short will cause the system to adjust frequently, increase the computing burden and possibly cause oscillation; setting the width too long will cause the system to respond slowly and affect the timeliness of temperature control.

[0041] S2: Before the temperature control starts, obtain the initial temperature of the blackbody through a sensor , in the embodiment of the present invention, the initial temperature of the blackbody . According to the auxiliary temperature and the initial temperature of the blackbody calculate the temperature control target difference as:

[0042] .

[0043] The temperature control target difference directly reflects the deviation degree between the current temperature and the target temperature, and is the basis for subsequent adjustment of the temperature control strategy.

[0044] Calculate the half-interval value of the temperature control target difference , and the calculation formula for the half-interval value is:

[0045] .

[0046] In order to reduce the temperature control calculation amount, when cannot be divided evenly by 2, the floor function can be used to determine the half-interval value .

[0047] S3: Obtain the real-time temperature of the blackbody with as the period, and set the temperature control method in stages according to the real-time temperature of the blackbody. Divide the temperature control target difference into different intervals, and adopt different temperature control strategies in different intervals to achieve step-by-step temperature control from rough to fine. In the embodiment of the present invention, the temperature control target difference is divided into three temperature control stages according to the actual experimental results. Specifically:

[0048] The first temperature control stage is set as , where .

[0049] The second temperature control stage is set as , where .

[0050] The third temperature control stage is set as .

[0051] Three temperature control methods, namely full-power temperature control, fixed duty cycle temperature control, and dynamic duty cycle temperature control, are designed corresponding to the three temperature control stages. Specifically as follows:

[0052] The first temperature control stage:

[0053] When the real-time temperature of the blackbody is in the interval, that is , adopt the full-power temperature control method, that is, in each cycle Among them, the output power control signal OUT is always at a high level of 1. That is, in this stage, the black body is temperature-controlled with the maximum heating or cooling capacity, so as to quickly raise or lower the temperature to the middle area of the temperature control target difference, and rapidly narrow the gap between the real-time temperature of the black body and the desired temperature of the black body.

[0054] Second temperature control stage:

[0055] When the real-time temperature of the black body is within the range, that is , a fixed duty cycle is used for temperature control. In the embodiment of the present invention, . The specific value of N can be adjusted according to the actual maximum temperature control power and the temperature control target difference. By adjusting the duty cycle, this stage can be changed. However, after N is determined, the duty cycle is always used for temperature control in the second temperature control stage. In each cycle , the time when the output power control signal OUT is at a high level of 1 is , and the remaining time is at a low level of 0. That is, in each cycle , the power control signal OUT is at a high level of 1 in the first , and from to the the power control signal is at a low level of 0. In the second temperature control stage, by reducing the duty cycle, the power output of heating or cooling is reduced, the temperature change rate is slowed down, and the temperature overshoot is avoided. At the same time, it continues to approach the target temperature. On the premise of ensuring a certain temperature control speed, the temperature control accuracy is improved, and it is avoided that after the real-time temperature of the black body approaches the auxiliary temperature, the temperature is difficult to control and continues to rise rapidly, resulting in a large temperature overshoot.

[0056] Third temperature control stage:

[0057] When the real-time temperature of the black body is within the range, that is , a method of dynamically adjusting the duty cycle of the temperature control signal for each cycle is used for temperature control. For each cycle , the duty cycle of the temperature control signal will change. The specific duty cycle is expressed as , that is, in the first ms of each cycle , the output power control signal OUT is at a high level of 1, and the remaining time the power control signal is at a low level of 0. As the real-time temperature of the black body continually approaches the auxiliary temperature , for each cycle The time when the output is high level 1 gradually becomes shorter, that is, the temperature control rate gradually decreases, avoiding excessive temperature overshoot. When the real-time temperature of the black body reaches the auxiliary temperature instantaneously, the entire cycle completely stops temperature control. Therefore, the real-time temperature of the black body will have a natural small drop. According to the overshoot characteristic, the real-time temperature of the black body will gradually rebound to the expected temperature of the black body , and will always be stable around , achieving a gradual approach to the target temperature and achieving the purpose of precise temperature control. It avoids the problems of excessive temperature overshoot or the temperature that cannot always be stable around in the traditional method.

[0058] In summary, the above description is only the preferred embodiment of this specification and is not used to limit the protection scope of this specification. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification shall be included within the protection scope of this specification.

[0059] The system, device, module or unit illustrated in the above one or more embodiments can be specifically implemented by a computer chip or entity, or by a product with a certain function. A typical implementation device is a computer. Specifically, the computer can be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0060] It should also be noted that the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to this process, method, commodity or device. Without further limitation, the element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, commodity or device including the said element.

[0061] Each embodiment in this specification is described in a progressive manner. The same or similar parts between each embodiment can be referred to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0062] The foregoing describes specific embodiments of the present specification. Other embodiments are within the scope of the appended claims. In some cases, the acts or steps recited in the claims may be performed in a different order than in the embodiments and still achieve the desired result. Additionally, the processes depicted in the figures do not necessarily require the particular order shown or sequential order to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. An on-orbit real-time adjustable blackbody temperature control method, characterized in that: include: Setting the temperature overshoot threshold , the temperature control auxiliary temperature is calculated according to the expected temperature of the black body: ； in, is the expected temperature of the black body, that is, the target temperature that the black body is expected to eventually reach; It is the auxiliary temperature in the temperature control process; Get the initial temperature of the blackbody , calculate the temperature control target difference as: ； by Get the real-time temperature of the black body for the period, and adjust the temperature according to the real-time temperature of the black body The temperature control method is set in stages: exist In the range, , each cycle The temperature control signal is always at high level; exist In the range, , each cycle The duty cycle of the temperature control signal is , the high level output time of the temperature control signal is , the remaining time is low level; exist Within the interval, dynamically adjust each cycle The duty cycle of the temperature control signal is adjusted to make the real-time temperature of the blackbody close to the expected temperature of the blackbody.

2. The on-orbit real-time adjustable blackbody temperature control method according to claim 1, characterized in that: The temperature overshoot threshold The value of is 3.

3. The on-orbit real-time adjustable blackbody temperature control method according to claim 1, characterized in that: cycle The value is 512ms.

4. The on-orbit real-time adjustable blackbody temperature control method according to claim 1, characterized in that: exist Each period within the interval The duty cycle of the temperature control signal is .

5. The on-orbit real-time adjustable blackbody temperature control method according to claim 1, characterized in that: exist Within the interval, each cycle The duty cycle of the temperature control signal is , the high level output time of the temperature control signal is , the remaining time is low level, so that the real-time temperature of the black body approaches the expected temperature of the black body.

6. The on-orbit real-time adjustable blackbody temperature control method according to claim 1, characterized in that: FPGA is used to set the temperature control method in stages according to the real-time temperature of the blackbody.

7. The on-orbit real-time adjustable blackbody temperature control method according to claim 1, characterized in that: The temperature control method is heating to increase the temperature or cooling to reduce the temperature.

8. The on-orbit real-time adjustable blackbody temperature control method according to claim 1, characterized in that: The temperature sensor is used to obtain the real-time temperature of the black body. The temperature sampling period of the temperature sensor is .

9. A blackbody temperature control system, characterized in that: The temperature of the black body is controlled by using the on-orbit real-time adjustable black body temperature control method as described in any one of claims 1 to 8.

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