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

Abstract

The invention relates to a spacecraft thermal environment monitoring processing system and method based on analytic hierarchy process, and belongs to the technical field of spacecraft telemetering monitoring. The system comprises a thermal environment range monitoring module, a thermal environment trend monitoring module and an over-limit comprehensive processing module, all the collected temperatures of the spacecraft are monitored on the basis of the range monitoring module, trend monitoring is taken as the core, trend monitoring interpretation is carried out on the collected temperatures about to be over-limit, and an over-limit comprehensive processing result is obtained. And the predicted temperature value and the predicted change slope are sent to a comprehensive processing module, and comprehensive treatment is carried out on different conditions according to levels. According to the method, trend monitoring is established for the thermal environment of the spacecraft based on analytic hierarchy process, the temperature change trend is determined before the temperature of the spacecraft area exceeds the limit, the working conditions possibly causing the limit exceeding are timely disposed in a graded and layered mode, and it is ensured that the temperature does not exceed the safety range for a long time.

Description

Technical Field

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

[0002] The current spacecraft telemetry monitoring and interpretation mainly includes range interpretation and conditional interpretation. Range interpretation mainly checks whether the relevant telemetry is between the upper and lower safety limits. When there is over-limit telemetry, an alarm will be issued through sound and event recording, but it does not have automatic handling capabilities, and it is too direct to only interpret whether it is within the safety range. For telemetry that requires a certain amount of time to change, such as temperature, it still has an upward and downward trend after exceeding the temperature safety limit, and will remain in the over-limit state for a period of time, which will have a bad impact on temperature-sensitive equipment. In addition to range interpretation, the current spacecraft test system can also perform conditional interpretation. Conditional interpretation itself is based on expert knowledge. By setting interpretation knowledge, complex working conditions of spacecraft can be monitored, which has a certain degree of flexibility. However, conditional interpretation requires the writing of interpretation pseudocode, and the interpretation rules for complex working conditions are difficult to write, resulting in limited application of conditional interpretation. Summary of the invention

[0003] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and to 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 comprehensive processing module;

[0006] Thermal environment range monitoring module: With the safe operating temperature range file of each channel of the spacecraft as input, it conducts normalized monitoring of all acquisition channels on the ground and on the spacecraft, and reads the temperature of all temperature measuring points in sequence according to the telemetry cycle. When the temperature of the temperature measuring loop enters the warning range, it will remind you through voice, transmit an event report, and remove the temperature measuring points that exceed the warning range from the range monitoring queue and put them into the thermal environment trend monitoring queue;

[0007] Thermal environment trend monitoring module: tracks and monitors the temperature of each temperature measuring point in the thermal environment trend monitoring queue, determines the temperature change trend of each temperature measuring point, predicts the temperature of each temperature measuring point and the temperature change slope of each temperature measuring point, and sends the predicted value and change slope of each temperature measuring point to the over-limit comprehensive processing module;

[0008] Over-limit comprehensive processing module: processes the temperature prediction value and change slope of each temperature measuring point output by the thermal environment trend monitoring module. If the temperature prediction value 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, trigger the safety disposal strategy; if the temperature prediction value 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, transmit a temperature recovery event report and continue trend monitoring; if the temperature prediction value does not exceed the warning range and the predicted slope returns to the normal direction, restore the on-board heating circuit to its initial state.

[0009] Preferably, the safety disposal strategy includes:

[0010] For the temperature control thermistor, when the upper limit is exceeded, the corresponding main and standby heating circuits are set to be normally off; when the lower limit is exceeded, the corresponding main and standby heating circuits are set to be normally on; and an alarm is issued in the form of sound and event report;

[0011] For temperature measurement thermistors, alarms are given through sound and event reports.

[0012] Preferably, the over-limit comprehensive processing module also monitors the heating circuit of the same safety switch according to the corresponding relationship between the safety switch and the heating circuit, and disconnects the safety switch when more than 50% of the predicted temperature values ​​of the heating circuits of the same safety switch exceed the safety upper limit and the predicted slope is positive.

[0013] Preferably, the thermal environment trend monitoring module predicts the temperature of each temperature measuring point and the change slope of the temperature of each temperature measuring point in the following manner:

[0014] Draw a temperature curve for each temperature measurement point, wherein the abscissa of the temperature curve is time and the ordinate is temperature;

[0015] The temperature curve of each temperature measuring point is smoothed using the local weighted scattered point smoothing algorithm;

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

[0017] By using the temperature curve of each temperature measuring point processed as above, the temperature of each temperature measuring point at any time in the future and the temperature change slope are predicted.

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

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

[0020]

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

[0022] Preferably, the weight w i (x0) is calculated using the Gaussian kernel function, and the formula is as follows:

[0023]

[0024] Among them, τ is a hyperparameter that controls the decay rate of the weight; x i is the ith temperature data point.

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

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

[0027] (1) The thermal environment range monitoring module performs normalized monitoring of all acquisition channels on the ground and on the spacecraft according to the safe operating temperature range file of each channel of the spacecraft, and 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, a voice reminder is given, and an event report is transmitted. The temperature measurement points that exceed the warning range are removed from the range monitoring queue and placed in the thermal environment trend monitoring queue, and then the process proceeds to step (2).

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

[0029] (3) The over-limit comprehensive processing module processes the temperature prediction value and change slope of each temperature measuring point output by the thermal environment trend monitoring module to determine whether there is a deterioration trend. If not, the process proceeds to step (4); if so, the process proceeds to step (5);

[0030] (4) Determine whether the satellite has returned to the safe range. If it has returned to the safe range, restore the initial state of the satellite 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 overrunning loop, and after the processing is completed, proceed to step (6);

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

[0033] Preferably, in step (5), the method for processing the overrunning loop is as follows:

[0034] If the temperature prediction value 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, the safety disposal strategy is triggered; if the temperature prediction value 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 temperature prediction value does not exceed the warning range and the predicted slope returns to the normal direction, the onboard heating circuit is restored to its initial state.

[0035] Preferably, the safety disposal strategy includes:

[0036] For the temperature control thermistor, when the upper limit is exceeded, the corresponding main and standby heating circuits are set to be normally off; when the lower limit is exceeded, the corresponding main and standby heating circuits are set to be normally on; and an alarm is issued in the form of sound and event report;

[0037] For temperature measurement thermistors, alarms are given through sound and event reports.

[0038] The beneficial effects of the present invention compared with the prior art are:

[0039] (1) The present invention establishes trend monitoring of the spacecraft thermal environment based on hierarchical analysis, determines the temperature change trend before the temperature in the spacecraft area exceeds the limit, and promptly handles the working conditions that may cause the temperature to exceed the limit in a hierarchical manner to ensure that the temperature does not exceed the safe range for a long time, expands the current temperature monitoring means, and realizes the autonomous handling of temperature exceeding the limit.

[0040] (2) The present invention embeds the temperature interpretation logic into the software system and uses the configuration parameters as the interpretation logic input, thereby avoiding the editing of complex interpretation knowledge and greatly reducing the manual preparation of data interpretation knowledge during the integrated testing of the spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Run processes for the system. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the accompanying drawings.

[0043] The system of the present invention comprises a thermal environment range monitoring module, a thermal environment trend monitoring module and an over-limit comprehensive processing module. The range monitoring module is used as a basis to monitor all the collected temperatures of the spacecraft. With trend monitoring as the core, trend monitoring and interpretation are performed on the collected temperatures that are about to exceed the limit. The predicted temperature value and the predicted change slope are sent to the comprehensive processing module, and comprehensive treatment is performed on different situations according to the levels.

[0044] 1. Thermal environment range monitoring module

[0045] Thermal environment range monitoring refers to the comprehensive monitoring of all satellite and ground acquisition channels. It uses the safe working range files of each channel of the spacecraft as input, conducts normalized monitoring of all channels, and reads the temperatures of all temperature measuring points in sequence according to the telemetry cycle. When the temperature of the temperature measurement loop enters the warning range (for example, the upper limit of the safety range is -3°, the lower limit of the safety range is +3°, and the parameters are configurable), the thermal environment range monitoring module reminds through voice and transmits event reports. The temperature measuring points that exceed the warning range are taken out of 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 measuring point in the monitoring queue, determining the temperature change trend of each temperature measuring point, and plotting an image of each temperature change with time as the horizontal axis. Then, using local weighted scattered point smoothing, a local linear regression model is fitted on each data point, and a greater weight is given to data points closer to the target point to achieve temperature data smoothing. The principle of the local weighted scattered point 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 ith data point and the target data point x0, y i is the true value of the ith data point. Weight w i (x0) is calculated using the Gaussian kernel function, and the formula is as follows:

[0050]

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

[0052] 3.Over-limit comprehensive processing module

[0053] The over-limit comprehensive processing module mainly processes the temperature prediction value and predicted change slope output by the trend monitoring module. 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, the safety disposal strategy is triggered. For the temperature control thermistor, its corresponding main and standby heating circuits are set to normally off (for exceeding the upper limit condition) or normally on (for exceeding the lower limit condition), and an alarm is issued in the form of sound and event report. For the temperature measurement thermistor, an alarm is issued in the form of sound and event report.

[0054] 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 returns to the normal direction, the onboard heating circuit is restored to its initial state.

[0055] In addition to taking safety measures for a single temperature measurement area, the over-limit comprehensive processing module simultaneously 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 of the same safety switch exceeds the safety upper limit and the predicted slope is positive, the safety switch is disconnected.

[0056] The system processing method of the present invention is as follows Figure 1 As shown, the following steps are included:

[0057] (1) The thermal environment range monitoring module performs normalized monitoring of all acquisition channels on the ground and on the spacecraft according to the safe operating temperature range file of each channel of the spacecraft, and 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, a voice reminder is given, and an event report is transmitted. The temperature measurement points that exceed the warning range are removed from the range monitoring queue and placed in the thermal environment trend monitoring queue, and then the process proceeds to step (2).

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

[0059] (3) The over-limit comprehensive processing module processes the temperature prediction value and change slope of each temperature measuring point output by the thermal environment trend monitoring module to determine whether there is a deterioration trend. If not, the process proceeds to step (4); if so, the process proceeds to step (5);

[0060] (4) Determine whether the satellite has returned to the safe range. If it has returned to the safe range, restore the initial state of the satellite 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 overrunning loop, and after the processing is completed, proceed to step (6);

[0062] The method for handling the over-limit circuit is as follows:

[0063] If the temperature prediction value 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, the safety disposal strategy is triggered; if the temperature prediction value 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 temperature prediction value does not exceed the warning range and the predicted slope returns to the normal direction, the onboard heating circuit is restored to its initial state.

[0064] Safe disposal strategies include:

[0065] For temperature control thermistors, when the upper limit is exceeded, the corresponding main and standby heating circuits are set to normally off; when the lower limit is exceeded, the corresponding main and standby heating circuits are set to normally on; 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.

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

[0067] The thermal environment range monitoring module ends monitoring after receiving the end monitoring instruction, otherwise it continues normal monitoring.

[0068] The present invention aims at the slowly changing telemetry represented by temperature, establishes trend monitoring for the spacecraft thermal environment based on hierarchical analysis, determines the temperature change trend before the temperature in the spacecraft area exceeds the limit, and handles the working conditions that may cause the limit in a timely manner in a hierarchical manner to ensure that the temperature does not exceed the safe range for a long time. The system of the present invention includes a thermal environment range monitoring module, a thermal environment trend monitoring module and an over-limit comprehensive processing module. The range monitoring module is used as the basis to monitor all the collected temperatures of the spacecraft, and the trend monitoring is used as the core to monitor and interpret the collected temperatures that are about to exceed the limit, and the predicted temperature value and the predicted change slope are sent to the comprehensive processing module, and different situations are comprehensively handled according to the hierarchy.

[0069] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A spacecraft thermal environment monitoring and processing system based on hierarchical analysis, characterized in that: It includes thermal environment range monitoring module, thermal environment trend monitoring module and over-limit comprehensive processing module; Thermal environment range monitoring module: With the safe operating temperature range file of each channel of the spacecraft as input, it conducts normalized monitoring of all acquisition channels on the ground and on the spacecraft, and reads the temperature of all temperature measuring points in sequence according to the telemetry cycle. When the temperature of the temperature measuring loop enters the warning range, it will remind you through voice, transmit an event report, and remove the temperature measuring points that exceed the warning range from the range monitoring queue and put them into the thermal environment trend monitoring queue; Thermal environment trend monitoring module: tracks and monitors the temperature of each temperature measuring point in the thermal environment trend monitoring queue, determines the temperature change trend of each temperature measuring point, predicts the temperature of each temperature measuring point and the temperature change slope of each temperature measuring point, and sends the predicted value and change slope of each temperature measuring point to the over-limit comprehensive processing module; Over-limit comprehensive 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 safety range and the slope is still positive, or exceeds the lower limit of the safety range and the slope is negative, the safety disposal strategy is triggered; If the temperature prediction value 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 temperature prediction value does not exceed the warning range and the predicted slope returns to the normal direction, the onboard heating circuit is restored to its initial state.

2. The spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 1 is characterized in that: Safe disposal strategies include: For the temperature control thermistor, when the upper limit is exceeded, the corresponding main and standby heating circuits are set to be normally off; when the lower limit is exceeded, the corresponding main and standby heating circuits are set to be normally on; and an alarm is issued in the form of sound and event report; For temperature measurement thermistors, alarms are given through sound and event reports.

3. The spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 1 is characterized in that: The over-limit comprehensive processing module also monitors the heating circuit of the same safety switch according to the corresponding relationship between the safety switch and the heating circuit. When more than 50% of the predicted temperature values ​​of the heating circuits of the same safety switch exceed the safety upper limit and the predicted 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 is characterized in that: The thermal environment trend monitoring module predicts the temperature of each temperature measurement point and the change slope of each temperature measurement point. The method is as follows: Draw a temperature curve for each temperature measurement point, wherein the abscissa of the temperature curve is time and the ordinate is temperature; The temperature curve of each temperature measuring point is smoothed using the local weighted scattered point smoothing algorithm; Fit a local linear regression model on each data point; By using the temperature curve of each temperature measuring point processed as above, the temperature of each temperature measuring point at any time in the future and the temperature change slope are predicted.

5. The spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 4 is characterized in that: The temperature curve of each temperature measurement point is smoothed using the local weighted scattered point smoothing algorithm. The method is as follows: For a given temperature target data point x0, its estimated value The calculation is as follows: where w i (x0) is the weight between the ith temperature data point and the temperature target data point x0, y i is the true value of the ith 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 is characterized in that: Weight w i (x0) is calculated using the Gaussian kernel function, and the formula is as follows: Among them, τ is a hyperparameter that controls the decay rate of the weight; x i is the ith temperature data point.

7. The spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to claim 6 is characterized in that: By controlling τ, the data points closer to the temperature target point have greater weights.

8. The monitoring and processing method of the spacecraft thermal environment monitoring and processing system based on hierarchical analysis according to any one of claims 1 to 7, characterized in that: The steps include: (1) The thermal environment range monitoring module performs normalized monitoring of all acquisition channels on the ground and on the spacecraft according to the safe operating temperature range file of each channel of the spacecraft, and 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, a voice reminder is given, and an event report is transmitted. The temperature measurement points that exceed the warning range are removed from the range monitoring queue and placed in the thermal environment trend monitoring queue, and then the process proceeds to step (2). (2) The thermal environment trend monitoring module tracks and monitors the temperature of each temperature measuring point in the thermal environment trend monitoring queue, predicts the temperature of each temperature measuring point and the change slope of the temperature of each temperature measuring point, and sends the predicted value and change slope of the temperature of each temperature measuring point to the over-limit comprehensive processing module, and enters step (3); (3) The over-limit comprehensive processing module processes the temperature prediction value and change slope of each temperature measuring point output by the thermal environment trend monitoring module to determine whether there is a deterioration trend. If not, the process proceeds to step (4); if so, the process proceeds to step (5); (4) Determine whether the satellite has returned to the safe range. If it has returned to the safe range, restore the initial state of the satellite 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 overrunning loop, and after the processing is completed, proceed to step (6); (6) Count the safety switches corresponding to the over-limit circuits, and determine whether there is a safety switch corresponding to more than 50% of the heating circuit temperature prediction values ​​exceeding the safety upper limit and the prediction slope is positive. If so, disconnect the safety switch and return to step (2); otherwise, directly return to step (2).

9. The monitoring processing method according to claim 8, characterized in that: In step (5), the method for processing the overrunning loop is as follows: If the temperature prediction value 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, the safety disposal strategy is triggered; if the temperature prediction value 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 temperature prediction value does not exceed the warning range and the predicted slope returns to the normal direction, the onboard heating circuit is restored to its initial state.

10. The monitoring processing method according to claim 9, characterized in that: Safe disposal strategies include: For the temperature control thermistor, when the upper limit is exceeded, the corresponding main and standby heating circuits are set to be normally off; when the lower limit is exceeded, the corresponding main and standby heating circuits are set to be normally on; and an alarm is issued in the form of sound and event report; For temperature measurement thermistors, alarms are given through sound and event reports.

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