A spacecraft thermal environment monitoring processing system and method based on analytic hierarchy process

Abstract

The application relates to a spacecraft thermal environment monitoring processing system and method based on analytic hierarchy process, and belongs to the technical field of spacecraft telemetry monitoring. The system comprises a thermal environment range monitoring module, a thermal environment trend monitoring module and an overrun comprehensive processing module. The whole collected temperature of the spacecraft is monitored based on the range monitoring module, the collected temperature about to overrun is monitored and interpreted in the trend monitoring mode, the predicted temperature value and the predicted change slope are sent into the comprehensive processing module, and different conditions are comprehensively disposed according to hierarchy. The application establishes the trend monitoring of the spacecraft thermal environment based on the analytic hierarchy process, determines the temperature change trend before the regional temperature of the spacecraft overruns, classifies and stratifies the working conditions that may cause the overrun, and timely disposes the working conditions, so that the temperature is ensured not to exceed the safety range for a long time.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft telemetry and monitoring technology, and relates to a spacecraft thermal environment monitoring and processing system and method based on hierarchical analysis. Background Technology

[0002] Current spacecraft telemetry monitoring and interpretation mainly consist of range interpretation and condition interpretation. Range interpretation primarily checks whether relevant telemetry data falls within safe limits. When telemetry data exceeds these limits, alarms are triggered via sound and event recording. However, it lacks automatic handling capabilities, and simply interpreting whether data is within the safe range is too direct. For telemetry data, such as temperature changes, which require a certain time frame, exceeding the temperature safety limit may still result in an upward or downward trend, maintaining an out-of-limit state for a period of time, which can have adverse effects on temperature-sensitive equipment. In addition to range interpretation, current spacecraft testing systems can also perform condition interpretation. Condition interpretation is based on expert knowledge and allows for monitoring of complex spacecraft operating conditions by setting interpretation rules, offering a degree of flexibility. However, condition interpretation requires writing interpretation pseudocode, and the difficulty in writing interpretation rules for complex operating conditions limits its application. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a spacecraft thermal environment monitoring and processing system and method based on hierarchical analysis.

[0004] The solution of the present invention is:

[0005] A spacecraft thermal environment monitoring and processing system based on hierarchical analysis includes a thermal environment range monitoring module, a thermal environment trend monitoring module, and an over-limit integrated processing module.

[0006] Thermal Environment Range Monitoring Module: Taking the safe operating temperature range file of each channel of the spacecraft as input, it performs routine monitoring of all acquisition channels between the spacecraft and the ground. It sequentially reads the temperature of all temperature measurement points according to the telemetry cycle. When the temperature of the temperature measurement loop enters the warning range, it provides a voice reminder and transmits an event report. It removes the temperature measurement points that exceed the warning range from the range monitoring queue and puts them into the thermal environment trend monitoring queue.

[0007] Thermal environment trend monitoring module: Tracks and monitors the temperature of each temperature measurement point in the thermal environment trend monitoring queue, judges the temperature change trend of each temperature measurement point, predicts the temperature of each temperature measurement point and the slope of the temperature change of each temperature measurement point, and sends the predicted temperature and the slope of the temperature change of each temperature measurement point to the over-limit integrated processing module.

[0008] The over-limit integrated processing module processes the temperature prediction value and change slope of each temperature measurement point output by the thermal environment trend monitoring module. If the temperature prediction value exceeds the upper limit of the safe range and the slope is still positive, or exceeds the lower limit of the safe range and the slope is negative, a safety handling strategy is triggered. If the temperature prediction value exceeds the upper limit of the safe range and the slope is negative, or exceeds the lower limit of the safe range and the slope is positive, a temperature recovery event report is transmitted and trend monitoring continues. If the temperature prediction value does not exceed the warning range and the prediction slope is returning to the normal direction, the initial state of the on-board heating circuit is restored.

[0009] Preferred safety handling strategies include:

[0010] For temperature-controlled thermistors, when the upper limit is exceeded, the corresponding main and backup heating circuits are set to normally closed; when the lower limit is exceeded, the corresponding main and backup heating circuits are set to normally open; and alarms are issued in the form of sound and event reports.

[0011] For temperature-sensing thermometers, alarms are issued via sound and event reports.

[0012] Preferably, the over-limit integrated processing module also monitors the heating circuit of the same safety switch according to the correspondence between the safety switch and the heating circuit. When the predicted temperature of more than 50% of the heating circuits of the same safety switch exceeds the safety limit and the prediction slope is positive, the safety switch is disconnected.

[0013] Preferably, the thermal environment trend monitoring module predicts the temperature at each measurement point and the slope of temperature change at each measurement point, using the following method:

[0014] A temperature curve is plotted for each temperature measurement point, with time on the horizontal axis and temperature on the vertical axis.

[0015] The temperature curve of each temperature measurement point is smoothed using a local weighted scatter smoothing algorithm.

[0016] Fit a local linear regression model at each data point;

[0017] Using the temperature curves of each temperature measurement point after the above processing, predict the temperature of each temperature measurement point at any future time and the slope of temperature change.

[0018] Preferably, the temperature curve of each temperature measurement point is smoothed using a local weighted scatter smoothing algorithm, as follows:

[0019] For a given target temperature data point x0, its estimated value is... The calculation is as follows:

[0020]

[0021] Where w i(x0) is the weight between the i-th temperature data point and the target temperature data point x0, y i is the true value of the i-th temperature data point; n is the total number of temperature data points.

[0022] Preferred weight w i (x0) is calculated using the Gaussian kernel function, as shown in the following formula:

[0023]

[0024] Where τ is a hyperparameter that controls the decay rate of the weights; x i Let i be the i-th temperature data point.

[0025] Preferably, by controlling τ, the data points closer to the temperature target point have a greater weight.

[0026] The monitoring and processing method of the spacecraft thermal environment monitoring and processing system based on hierarchical analysis includes the following steps:

[0027] (1) The thermal environment range monitoring module monitors all acquisition channels between the spacecraft and the ground in a normalized manner according to the safe operating temperature range document of each channel of the spacecraft. It reads the temperature of all temperature measurement points in sequence according to the telemetry cycle. When the temperature of the temperature measurement loop enters the warning range, it reminds the user through voice and transmits the event report. It removes the temperature measurement points that exceed the warning range from the range monitoring queue and puts them into the thermal environment trend monitoring queue, and then proceeds to step (2).

[0028] (2) The thermal environment trend monitoring module tracks and monitors the temperature of each temperature measurement point in the thermal environment trend monitoring queue, predicts the temperature of each temperature measurement point and the slope of the temperature change of each temperature measurement point, and sends the predicted value and the slope of the temperature change of each temperature measurement point to the over-limit integrated processing module, and enters step (3).

[0029] (3) The over-limit integrated processing module processes the temperature prediction value and change slope of each temperature measurement point output by the thermal environment trend monitoring module to determine whether there is a deterioration trend. If there is no deterioration trend, proceed to step (4); if there is, proceed to step (5).

[0030] (4) Determine whether it has returned to the safe range. If it has returned to the safe range, restore the initial state of the on-board heating circuit and return to step (1) to continue normal monitoring. If it has not returned to the safe range, return to step (2).

[0031] (5) Process the over-limit circuit, and proceed to step (6) after processing is completed;

[0032] (6) Count the safety switches corresponding to the over-limit circuits and determine whether there are any heating circuits with more than 50% of the temperature prediction values ​​corresponding to the same safety switch that exceed the safety limit and the prediction slope is positive. If so, disconnect the safety switch and return to step (2); otherwise, return directly to step (2).

[0033] Preferably, in step (5), the method for processing the over-limit circuit is as follows:

[0034] If the predicted temperature exceeds the upper limit of the safety range and the slope is still positive, or exceeds the lower limit of the safety range and the slope is negative, a safety handling strategy is triggered; if the predicted temperature exceeds the upper limit of the safety range and the slope is negative, or exceeds the lower limit of the safety range and the slope is positive, a temperature recovery event report is transmitted and trend monitoring continues; if the predicted temperature does not exceed the warning range and the predicted slope is returning to the normal direction, the initial state of the onboard heating circuit is restored.

[0035] Preferred safety handling strategies include:

[0036] For temperature-controlled thermistors, when the upper limit is exceeded, the corresponding main and backup heating circuits are set to normally closed; when the lower limit is exceeded, the corresponding main and backup heating circuits are set to normally open; and alarms are issued in the form of sound and event reports.

[0037] For temperature-sensing thermometers, alarms are issued via sound and event reports.

[0038] The advantages of this invention compared to the prior art are:

[0039] (1) This invention establishes trend monitoring of the spacecraft thermal environment based on hierarchical analysis, determines the temperature change trend before the temperature in the spacecraft region exceeds the limit, classifies and handles the operating conditions that may cause the limit in a timely manner, ensures that the temperature does not exceed the safe range for a long time, expands the current temperature monitoring methods, and realizes autonomous handling of temperature over-limit.

[0040] (2) The present invention embeds the temperature interpretation logic into the software system and uses the configuration parameters as the input of the interpretation logic, avoiding the editing of complex interpretation knowledge and greatly reducing the manual preparation of data interpretation knowledge during the comprehensive testing of spacecraft. Attached Figure Description

[0041] Figure 1 This describes the system's operational process. Detailed Implementation

[0042] The invention will now be further described with reference to the accompanying drawings.

[0043] The system of this invention includes a thermal environment range monitoring module, a thermal environment trend monitoring module, and an over-limit comprehensive processing module. Based on the range monitoring module, all the temperature data collected by the spacecraft is monitored. With the trend monitoring as the core, the system performs trend monitoring and interpretation on the collected temperature that is about to exceed the limit. The predicted temperature value and the predicted change slope are sent to the comprehensive processing module, which performs comprehensive processing on different situations according to the level.

[0044] 1. Thermal environment range monitoring module

[0045] Thermal environment range monitoring refers to comprehensive monitoring of all acquisition channels between spacecraft and ground. Using the safe operating range files of each channel of the spacecraft as input, all channels are monitored routinely. The temperature of all temperature measurement points is read sequentially according to the telemetry cycle. When the temperature of the temperature measurement loop enters the warning range (e.g., the upper limit of the safe range -3°C, the lower limit of the safe range +3°C, parameters are configurable), the thermal environment range monitoring module will issue a voice reminder and transmit an event report. Temperature measurement points that exceed the warning range will be removed from the range monitoring queue and placed in the thermal environment trend monitoring queue for further monitoring.

[0046] 2. Thermal Environment Trend Monitoring Module

[0047] Thermal environment trend monitoring refers to tracking and monitoring the temperature of each temperature measurement point in the monitoring queue, determining the temperature change trend of each measurement point, and plotting a graph of each temperature change with time as the x-axis. Then, locally weighted scatter smoothing is used to fit a local linear regression model on each data point, giving greater weight to data points closer to the target point to achieve temperature data smoothing. The principle of the locally weighted scatter smoothing algorithm is as follows: For a given target data point x0, the estimated value of the target data point... The calculation is as follows:

[0048]

[0049] Where w i (x0) is the weight between the i-th data point and the target data point x0, y i Let w be the true value of the i-th data point. i (x0) is calculated using the Gaussian kernel function, as shown in the following formula:

[0050]

[0051] Where τ is a hyperparameter that controls the decay rate of the weights. i -x0 represents the distance between the i-th temperature data point and the target temperature data point x0. Based on the formula, the temperature change trend after the current point can be predicted, and the slope of the temperature change at the current point can be calculated. The predicted temperature and the slope are then output to the over-limit integrated processing module.

[0052] 3. Over-limit integrated processing module

[0053] The over-limit integrated processing module mainly processes the temperature prediction value and prediction change slope output by the trend monitoring module. If the predicted temperature exceeds the upper limit of the safe range and the slope is still positive, or exceeds the lower limit of the safe range and the slope is negative, a safety handling strategy is triggered. For temperature control thermistors, the corresponding main and backup heating circuits are set to normally closed (for over-upper limit conditions) or normally open (for over-lower limit conditions), and alarms are issued in the form of sound and event reports. For temperature measurement thermistors, alarms are issued in the form of sound and event reports.

[0054] If the predicted temperature exceeds the upper limit of the safe range and the slope is negative, or exceeds the lower limit of the safe range and the slope is positive, a temperature recovery event report is transmitted and trend monitoring continues; if the predicted temperature does not exceed the warning range and the predicted slope is returning to the normal direction, the initial state of the on-board heating circuit is restored.

[0055] In addition to taking safety measures for a single temperature measurement area, the over-limit integrated processing module monitors the heating circuits of the same safety switch simultaneously according to the correspondence between the safety switch and the heating circuit. When more than 50% of the heating circuits of the same safety switch predict the temperature to exceed the safety limit and the prediction slope is positive, the safety switch is disconnected.

[0056] The system processing method of this invention is as follows: Figure 1 As shown, it includes the following steps:

[0057] (1) The thermal environment range monitoring module monitors all acquisition channels between the spacecraft and the ground in a normalized manner according to the safe operating temperature range document of each channel of the spacecraft. It reads the temperature of all temperature measurement points in sequence according to the telemetry cycle. When the temperature of the temperature measurement loop enters the warning range, it reminds the user through voice and transmits the event report. It removes the temperature measurement points that exceed the warning range from the range monitoring queue and puts them into the thermal environment trend monitoring queue, and then proceeds to step (2).

[0058] (2) The thermal environment trend monitoring module tracks and monitors the temperature of each temperature measurement point in the thermal environment trend monitoring queue, predicts the temperature of each temperature measurement point and the slope of the temperature change of each temperature measurement point, and sends the predicted value and the slope of the temperature change of each temperature measurement point to the over-limit integrated processing module, and enters step (3).

[0059] (3) The over-limit integrated processing module processes the temperature prediction value and change slope of each temperature measurement point output by the thermal environment trend monitoring module to determine whether there is a deterioration trend. If there is no deterioration trend, proceed to step (4); if there is, proceed to step (5).

[0060] (4) Determine whether it has returned to the safe range. If it has returned to the safe range, restore the initial state of the on-board heating circuit and return to step (1) to continue normal monitoring. If it has not returned to the safe range, return to step (2).

[0061] (5) Process the over-limit circuit, and proceed to step (6) after processing is completed;

[0062] The method for handling out-of-limit circuits is as follows:

[0063] If the predicted temperature exceeds the upper limit of the safety range and the slope is still positive, or exceeds the lower limit of the safety range and the slope is negative, a safety handling strategy is triggered; if the predicted temperature exceeds the upper limit of the safety range and the slope is negative, or exceeds the lower limit of the safety range and the slope is positive, a temperature recovery event report is transmitted and trend monitoring continues; if the predicted temperature does not exceed the warning range and the predicted slope is returning to the normal direction, the initial state of the onboard heating circuit is restored.

[0064] Safety response strategies include:

[0065] For temperature-controlled thermistors, when the upper limit is exceeded, the corresponding main and backup heating circuits are set to normally closed; when the lower limit is exceeded, the corresponding main and backup heating circuits are set to normally open; and alarms are issued in the form of sound and event reports. For temperature-measuring thermistors, alarms are issued in the form of sound and event reports.

[0066] (6) Count the safety switches corresponding to the over-limit circuits and determine whether there are any heating circuits with more than 50% of the temperature prediction values ​​corresponding to the same safety switch that exceed the safety limit and the prediction slope is positive. If so, disconnect the safety switch and return to step (2); otherwise, return directly to step (2).

[0067] The thermal environment range monitoring module will stop monitoring upon receiving a command to end monitoring; otherwise, it will continue to perform routine monitoring.

[0068] This invention targets slowly changing telemetry, exemplified by temperature. Based on hierarchical analysis, it establishes trend monitoring of the spacecraft's thermal environment, determining temperature change trends before temperatures exceed limits in certain areas. It then classifies and addresses potential exceedances in a tiered manner to ensure temperatures do not exceed safe ranges for extended periods. The system comprises a thermal environment range monitoring module, a thermal environment trend monitoring module, and an exceedance comprehensive processing module. The range monitoring module monitors all acquired temperatures from the spacecraft. The trend monitoring module, as the core, analyzes and interprets the trends of acquired temperatures approaching exceedances. The predicted temperature values ​​and predicted change slopes are then sent to the comprehensive processing module for tiered and integrated handling of different situations.

[0069] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A spacecraft thermal environment monitoring and processing system based on hierarchical analysis, characterized in that: Includes a thermal environment range monitoring module, a thermal environment trend monitoring module, and an over-limit comprehensive processing module; Thermal Environment Range Monitoring Module: Taking the safe operating temperature range file of each channel of the spacecraft as input, it performs routine monitoring of all acquisition channels between the spacecraft and the ground. It sequentially reads the temperature of all temperature measurement points according to the telemetry cycle. When the temperature of the temperature measurement loop enters the warning range, it provides a voice reminder and transmits an event report. It removes the temperature measurement points that exceed the warning range from the range monitoring queue and puts them into the thermal environment trend monitoring queue. Thermal environment trend monitoring module: Tracks and monitors the temperature of each temperature measurement point in the thermal environment trend monitoring queue, judges the temperature change trend of each temperature measurement point, predicts the temperature of each temperature measurement point and the slope of the temperature change of each temperature measurement point, and sends the predicted temperature and the slope of the temperature change of each temperature measurement point to the over-limit integrated processing module. Over-limit integrated processing module: Processes the temperature prediction value and change slope of each temperature measurement point output by the thermal environment trend monitoring module. If the temperature prediction value exceeds the upper limit of the safe range and the slope is still positive, or exceeds the lower limit of the safe range and the slope is negative, the safety handling strategy is triggered. If the predicted temperature exceeds the upper limit of the safety range and the slope is negative, or exceeds the lower limit of the safety range and the slope is positive, a temperature recovery event report is transmitted and trend monitoring continues; if the predicted temperature does not exceed the warning range and the predicted slope is returning to the normal direction, the initial state of the onboard heating circuit is restored.

2. The spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 1, characterized in that: Safety response strategies include: For temperature-controlled thermistors, when the upper limit is exceeded, the corresponding main and backup heating circuits are set to normally closed; when the lower limit is exceeded, the corresponding main and backup heating circuits are set to normally open; and alarms are issued in the form of sound and event reports. For temperature-sensing thermometers, alarms are issued via sound and event reports.

3. The spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 1, characterized in that: The over-limit integrated processing module also monitors the heating circuits of the same safety switch according to the correspondence between the safety switch and the heating circuit. When the predicted temperature of more than 50% of the heating circuits corresponding to the same safety switch exceeds the safety limit and the prediction slope is positive, the safety switch is disconnected.

4. The spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 1, characterized in that: The thermal environment trend monitoring module predicts the temperature at each measurement point and the slope of temperature change at each measurement point, using the following method: A temperature curve is plotted for each temperature measurement point, with time on the horizontal axis and temperature on the vertical axis. The temperature curve of each temperature measurement point is smoothed using a local weighted scatter smoothing algorithm. Fit a local linear regression model at each data point; Using the temperature curves of each temperature measurement point after the above processing, predict the temperature of each temperature measurement point at any future time and the slope of temperature change.

5. A spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 4, characterized in that: The temperature curve for each temperature measurement point is smoothed using a locally weighted scatter smoothing algorithm, as follows: For a given target temperature data point x0, its estimated value is... The calculation is as follows: Where w i (x0) is the weight between the i-th temperature data point and the target temperature data point x0, y i is the true value of the i-th temperature data point; n is the total number of temperature data points.

6. The spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 5, characterized in that: weight w i (x0) is calculated using the Gaussian kernel function, as shown in the following formula: Where τ is a hyperparameter that controls the decay rate of the weights; x i Let i be the i-th temperature data point.

7. A spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 6, characterized in that: By controlling τ, the data points closer to the temperature target point are given a greater weight.

8. The monitoring and processing method of the spacecraft thermal environment monitoring and processing system based on hierarchical analysis as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) The thermal environment range monitoring module monitors all acquisition channels between the spacecraft and the ground in a normalized manner according to the safe operating temperature range document of each channel of the spacecraft. It reads the temperature of all temperature measurement points in sequence according to the telemetry cycle. When the temperature of the temperature measurement loop enters the warning range, it reminds the user through voice and transmits the event report. It removes the temperature measurement points that exceed the warning range from the range monitoring queue and puts them into the thermal environment trend monitoring queue, and then proceeds to step (2). (2) The thermal environment trend monitoring module tracks and monitors the temperature of each temperature measurement point in the thermal environment trend monitoring queue, predicts the temperature of each temperature measurement point and the slope of the temperature change of each temperature measurement point, and sends the predicted value and the slope of the temperature change of each temperature measurement point to the over-limit integrated processing module, and enters step (3). (3) The over-limit integrated processing module processes the temperature prediction value and change slope of each temperature measurement point output by the thermal environment trend monitoring module to determine whether there is a deterioration trend. If there is no deterioration trend, proceed to step (4); if there is, proceed to step (5). (4) Determine whether it has returned to the safe range. If it has returned to the safe range, restore the initial state of the on-board heating circuit and return to step (1) to continue normal monitoring. If it has not returned to the safe range, return to step (2). (5) Process the over-limit circuit, and proceed to step (6) after processing is completed; (6) Count the safety switches corresponding to the over-limit circuits and determine whether there are any heating circuits with more than 50% of the temperature prediction values ​​corresponding to the same safety switch that exceed the safety limit and the prediction slope is positive. If so, disconnect the safety switch and return to step (2); otherwise, return directly to step (2).

9. The monitoring and processing method according to claim 8, characterized in that, In step (5), the method for handling the over-limit circuit is as follows: If the predicted temperature exceeds the upper limit of the safety range and the slope is still positive, or exceeds the lower limit of the safety range and the slope is negative, a safety handling strategy is triggered; if the predicted temperature exceeds the upper limit of the safety range and the slope is negative, or exceeds the lower limit of the safety range and the slope is positive, a temperature recovery event report is transmitted and trend monitoring continues; if the predicted temperature does not exceed the warning range and the predicted slope is returning to the normal direction, the initial state of the onboard heating circuit is restored.

10. The monitoring and processing method according to claim 9, characterized in that, Safety response strategies include: For temperature-controlled thermistors, when the upper limit is exceeded, the corresponding main and backup heating circuits are set to normally closed; when the lower limit is exceeded, the corresponding main and backup heating circuits are set to normally open; and alarms are issued in the form of sound and event reports. For temperature-sensing thermometers, alarms are issued via sound and event reports.

Images