Emergency alarm method and system based on satellite communication

Abstract

The invention belongs to the technical field of satellite communication, and particularly relates to an emergency alarm method and system based on satellite communication, and the method comprises the steps: capturing the current longitude and latitude coordinates and current environment parameters of an inspection object in real time, and storing the corresponding data of a preset time period as a current historical coordinate sequence and a current historical environment set; calculating a current space-time silence index; calculating a current alarm urgency coefficient; obtaining a current dynamic step length factor; obtaining a current data bit truncation value; generating a position data segment; calculating a residual available bit space according to the total capacity of the message space obtained in advance, and filling the residual available bit space according to the priority degree of each data of the current environment parameter; and sending a message to execute data state write-back and update historical related data. According to the invention, the technical problems of bandwidth waste and inaccurate emergency alarm information caused by fixed coding are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of satellite communication technology. More specifically, this invention relates to an emergency alarm method and system based on satellite communication. Background Technology

[0002] In industrial applications such as geological disaster monitoring, due to the limitations of ground-based cellular network coverage, BeiDou satellite communication has become an important means of ensuring data transmission and emergency alarms. The location information and environmental status data of the objects being inspected, such as inspection personnel, vehicles or buoys, are the core monitoring indicators.

[0003] The industry typically uses fixed-length frame structures to encapsulate data. For example, GPS latitude and longitude data are usually uniformly encoded as double-precision floating-point numbers, with 8 bytes per dimension, while sensor values ​​occupy a fixed 2 or 4 bytes. This fixed-format static encoding method is acceptable in broadband network environments, but in narrowband scenarios of satellite short message communication, it is necessary to simplify the complex environmental situation transmission problem into a fixed-format data padding problem. However, this fixed-format method has an inherent limitation: it assumes that the accuracy requirements and redundancy of the data are constant. In real industrial settings, when the object being inspected is stationary or moving slowly, the higher latitude and longitude values ​​(degrees and minutes) change very little or remain constant, and repeated transmissions waste bandwidth. In emergency situations requiring distress or rescue, sub-meter accuracy is needed to assist in search and rescue, and environmental data such as gas concentrations must be transmitted simultaneously.

[0004] Existing technologies employ a single, fixed-width encoding model, which cannot dynamically adjust the precision of data according to the urgency of the scenario. For example, low-precision coordinates are sent under normal circumstances, while high-precision coordinates are sent when an alarm is triggered. This results in the inability to simultaneously send high-precision coordinates and complete environmental situation information within a short message packet at critical moments due to message length limitations. This phenomenon restricts the reliability and application depth of this technology in emergency rescue scenarios. Summary of the Invention

[0005] To address the technical problems of bandwidth waste and inaccurate emergency alarm information caused by the use of fixed encoding in the prior art, the present invention provides solutions in the following aspects.

[0006] In a first aspect, the present invention provides an emergency alarm method based on satellite communication, comprising: The system captures the current latitude and longitude coordinates and current environmental parameters of the inspected object in real time, and stores the corresponding data for a preset time period as the current historical coordinate sequence and the current historical environment set. Simultaneously, it retrieves the coordinates from the previous moment from memory. Based on the difference between the displacement obtained from the current latitude and longitude coordinates and the fluctuation degree of the current historical coordinate sequence, it calculates the current spatiotemporal silence index. Based on the average abnormal fluctuation degree of different data in the current environmental parameters, it calculates the current alarm urgency coefficient. It multiplies the result of the exponential operation of the difference between the current spatiotemporal silence index and the current alarm urgency coefficient with the current coordinate standard deviation to obtain the current dynamic step size factor. It determines the actual maximum displacement based on the sum of the current displacement status of the inspected object and the current coordinate standard deviation, divides it by the current dynamic step size factor to obtain the minimum required number of discrete states, and then performs binary conversion to obtain the current data bit truncation value. It takes the value of the difference between the current displacement change and the dynamic step size factor and truncates it to generate a position data segment. It calculates the remaining available bit space based on the pre-acquired total message space capacity and fills it according to the priority of each data in the current environmental parameters. It sends a message to execute data status write-back and update relevant historical data.

[0007] This invention addresses the problems of bandwidth waste, inaccurate status assessment, and low message information value caused by fixed encoding in satellite emergency alarm scenarios. It constructs a complete dynamic adaptation solution, which involves: ensuring continuous data acquisition by pre-activating the communication terminal; dynamically assessing the status of inspected objects and environmental risks based on historical data; adjusting the calculation precision and bit usage of positioning data; optimizing message bit allocation and data filling logic; and finally ensuring system stability through a reasonable status write-back mechanism. This solution adapts the acquisition, assessment, and transmission of positioning and environmental data to different scenario requirements, reduces bandwidth waste, improves the accuracy of status and risk assessment, and ensures more efficient transmission of emergency alarm information.

[0008] Preferably, the current latitude and longitude coordinates and current environmental parameters of the inspected object are captured in real time, and the corresponding data for a preset time period are stored as the current historical coordinate sequence and the current historical environment set, including: Before the inspected object enters an area without public network coverage, the onboard communication terminal is activated to obtain the current latitude and longitude coordinates in real time, including current environmental parameters such as the inspector's heart rate, ambient temperature, and gas concentration; and the most recently stored data is stored. The current historical coordinate sequence and current historical environment set of each historical moment; retrieve the reference coordinates of the last successful message transmission at the current moment from the local memory, and record them as the coordinates of the previous moment.

[0009] Preferably, the current spatiotemporal silence index satisfies the following expression: ; In the formula, Represents the spatiotemporal silence index, with a range of values. ; Indicates the current latitude and longitude coordinates. This represents the latitude and longitude coordinates of the previous moment, in square meters; Indicates the standard deviation of the current coordinates; It represents a very small positive number, and guarantees that the denominator is not 0.

[0010] The spatiotemporal silence index calculation method constructed by this invention effectively reduces the limitations of relying on fixed thresholds to judge the status of inspected objects. By combining the fluctuation characteristics of the current displacement and historical coordinates, it can automatically distinguish between false displacement caused by signal drift and real movement status. When the signal environment is poor, it filters out invalid noise to avoid misjudgment; when the signal is stable, it accurately identifies minute movements to prevent missed judgment.

[0011] Preferably, the current alarm urgency coefficient satisfies the following expression: ; In the formula, This indicates the current alarm urgency level. Indicates the data type in the current environment parameters. The value; This represents the average value of data type j in the current historical environment set; This represents the standard deviation of data type j in the current historical environment set; This refers to the data types in the current environmental parameters; It represents a very small positive number, and guarantees that the denominator is not 0.

[0012] The alarm urgency coefficient calculation method of this invention overcomes the shortcomings of judging danger by single environmental data or fixed thresholds. It comprehensively reflects the true situation of the environment in which the inspected object is located by integrating the abnormality of multiple environmental parameters, and at the same time maps the abnormality to a reasonable range, thus realizing the assessment of the degree of danger.

[0013] Preferably, obtaining the current dynamic step size factor includes: Calculate the difference between the current spatiotemporal silence index and the current alarm urgency coefficient. Perform an exponential operation on the difference with the natural constant as the base. Multiply the result of the exponential operation by the current coordinate standard deviation to obtain the current dynamic step size factor.

[0014] The dynamic step size factor generated by this invention breaks away from the fixed accuracy assessment model. It adjusts the calculation granularity of positioning data based on scene conditions and signal noise levels. When the inspected object is in a safe and quiet state, the calculation granularity is increased to save communication bandwidth; in emergency and high-risk situations, the calculation granularity is decreased to improve positioning accuracy. This dynamic adjustment method allows the accuracy of positioning data to adapt to different scenario requirements, balancing the bandwidth consumption of daily monitoring with the accuracy requirements in emergency situations.

[0015] Preferably, the current data bit truncation value satisfies the following expression: ; In the formula, Indicates the current data bit truncation value; This represents the absolute value of the displacement of the current longitude coordinate from the longitude coordinate of the previous time point; This represents the absolute value of the displacement of the current latitude coordinate from the latitude coordinate of the previous moment; This indicates the standard deviation of the current coordinates, in meters. Indicates the current dynamic step size factor; Represents a very small positive number, ensuring that the denominator is not zero; It is a rounding function; Represents a logarithmic function.

[0016] The bit truncation value calculation method of the present invention effectively solves the problem of bandwidth waste or insufficient accuracy caused by fixed bit allocation. It combines actual displacement and noise characteristics to determine the physical range of data transmission, and then converts it into an appropriate number of bits, ensuring that the number of bits can cover the required positioning information without occupying too much bandwidth.

[0017] Preferably, generating a location data segment includes: Calculate the difference between the current latitude and longitude coordinates and the coordinates at the previous time and divide it by the dynamic step size factor. Perform a rounding operation on the obtained quotient and then truncate the rounding result according to the preset number of bits M to generate a position data segment.

[0018] Preferably, the remaining available bit space is calculated based on the pre-acquired total message space capacity, and then filled according to the priority of each data in the current environment parameters, including: Obtain the total message space capacity specified by the short message protocol from the satellite parameter system, and subtract the number of bits for the position data segment to obtain the remaining available bits; calculate the standardized deviation of each data of the current environmental parameters; establish a priority queue based on the magnitude of the standardized deviation, and place the data with the largest deviation in the high priority to obtain the environmental parameter queue; according to the remaining available bits, sequentially extract the corresponding data from the environmental parameter queue from high priority to low priority and fill it into the message until the remaining available bits are exhausted.

[0019] Preferably, sending a message performs data status write-back and updates historical related data, including: If the message is successfully generated and sent, the current latitude and longitude coordinates will be overwritten into the system's global state context as the coordinates of the previous moment in the next cycle. At the same time, regardless of whether the sending is successful or not, the current latitude and longitude coordinates and the current environmental parameters will be integrated into the current historical coordinate sequence and the current historical environment set, and the oldest data will be removed to form a data loop.

[0020] Secondly, the present invention provides an emergency alarm system based on satellite communication, including a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the above-mentioned emergency alarm method based on satellite communication is implemented.

[0021] By adopting the above technical solution, the above-mentioned emergency alarm method based on satellite communication is generated into a computer program and stored in a memory so that it can be loaded and executed by a processor. In this way, a terminal device can be made based on the memory and the processor for convenient use.

[0022] The beneficial effects of this invention are as follows: Based on the application scenario of satellite narrowband communication, this invention breaks through the traditional fixed data processing and transmission mode, and constructs a dynamic adaptation system that fits actual emergency needs. From the advance deployment of data collection, to the assessment of status and risk, to the dynamic balance between data accuracy and transmission bandwidth, and finally to the optimized filling of message information and the construction of data closed loop, it is designed around the actual needs of emergency scenarios. This ensures both the efficient use of resources during daily monitoring and the accurate and comprehensive transmission of key information in emergency situations. This invention enhances the intelligence and practicality of satellite emergency alarm systems, and provides technical support for inspection and monitoring and emergency rescue in areas without public network coverage. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the emergency alarm method based on satellite communication in this invention. Detailed Implementation

[0024] This invention discloses an emergency alarm method based on satellite communication, referring to... Figure 1 This includes steps S1-S4: S1: Real-time capture of the current latitude and longitude coordinates and current environmental parameters of the inspected object, and store the corresponding data for a preset time period as the current historical coordinate sequence and the current historical environment set; at the same time, retrieve the coordinates of the previous moment from the memory.

[0025] It should be noted that existing industrial data transmission protocols typically employ fixed-length frame structures. For example, GPS data always occupies 16 bytes of double-precision floating-point numbers. However, in narrowband satellite communication scenarios, this fixed-format encoding method results in significant bandwidth waste. This invention, by introducing historical reference coordinates and a sliding statistical window, establishes a dynamic comparison benchmark, breaking the limitations of the fixed frame structure and providing raw input for subsequent analysis of the spatiotemporal redundancy and scenario urgency of the data.

[0026] It should be noted that the switch between terrestrial cellular networks and satellite communication requires a process, and the satellite terminal also needs to complete satellite acquisition and signal synchronization after startup. If startup is delayed until entering an area without a public network, a brief communication vacuum may occur. Once the objects being inspected enter these areas, they may face emergencies such as geological disasters, getting lost, or equipment malfunctions. The communication vacuum will prevent timely monitoring of data and the transmission of alarm information, creating potential safety hazards.

[0027] Specifically, the system captures the current latitude and longitude coordinates and current environmental parameters of the inspected object in real time, and stores the corresponding data for a preset time period as the current historical coordinate sequence and the current historical environment set; simultaneously, it retrieves the coordinates from the previous moment from the memory, including: Before the inspected object enters an area without public network coverage, the onboard communication terminal is activated to obtain the current latitude and longitude coordinates in real time, including current environmental parameters such as the inspector's heart rate, ambient temperature, and gas concentration; and the most recently stored data is stored. The current historical coordinate sequence and current historical environment set of each historical moment; retrieve the reference coordinates of the last successful message transmission at the current moment from the local memory, and record them as the coordinates of the previous moment.

[0028] It should be noted that the preset time period specifically refers to the most recent N historical moments, where N is a positive integer pre-configured by the system, and N≥3. It can be adjusted according to the monitoring frequency and data storage requirements of the inspection scenario. For example, with a monitoring frequency of 1 historical moment every 5 minutes, N=12 corresponds to a preset time period of 1 hour.

[0029] At this point, we have obtained the current latitude and longitude coordinates, current environmental parameters, current historical coordinate sequence, current historical environmental set, and coordinates at the previous moment.

[0030] S2: Calculate the current spatiotemporal silence index based on the difference between the displacement magnitude obtained from the current latitude and longitude coordinates and the fluctuation degree of the current historical coordinate sequence; calculate the current alarm urgency coefficient based on the average abnormal fluctuation degree of different data in the current environmental parameters.

[0031] It should be noted that traditional techniques for determining whether an object is stationary typically rely on a fixed threshold; for example, a displacement of less than 5 meters is considered stationary. However, satellite signal drift errors are dynamic. A fixed threshold can lead to frequent false alarms when the signal is poor, and a drift greater than 5 meters can lead to missed alarms when the signal is good. Minor movements of less than 5 meters can also cause false alarms. This invention aims to utilize the statistical characteristics of the data itself to construct an adaptive judgment model that does not require a manual threshold: the current spatiotemporal stillness index. This index is the core adaptive indicator in satellite emergency alarm systems for determining whether an inspected object is stationary or in a low-dynamic state. It integrates features of spatial location and time dimensions, and does not simply rely on current displacement. Instead, it combines the dynamic standard deviation of historical coordinates to distinguish between false movements caused by real signal drift.

[0032] Specifically, based on the difference between the displacement magnitude obtained from the current latitude and longitude coordinates and the fluctuation degree of the current historical coordinate sequence, the current spatiotemporal silence index is calculated, including: Calculate the square of the standard deviation of the current historical coordinate sequence, and denot it as the current coordinate standard deviation; It should be noted that this expression utilizes the concept of Mahalanobis distance in statistics. When the inspected object is in a severely obstructed area causing drastic signal drift, the standard deviation of the current coordinates increases, the denominator increases, and even if the numerator is large, the current spatiotemporal silence index remains close to 1, thus determining that the inspected object is in a silent state and automatically filtering drift noise. When the signal is stable, the standard deviation of the current coordinates is extremely small, and even a small real movement will cause the current spatiotemporal silence index to drop rapidly, thus determining that the inspected object is in a moving state.

[0033] The current spatiotemporal quiescence index satisfies the following expression: ; In the formula, Represents the spatiotemporal silence index, with a range of values. ; Indicates the current latitude and longitude coordinates. This represents the latitude and longitude coordinates of the previous moment, in square meters; Indicates the standard deviation of the current coordinates; It represents a very small positive number, and guarantees that the denominator is not 0.

[0034] In the formula, This represents the sum of squares of the differences between the current latitude and longitude coordinates and the previous latitude and longitude coordinates. It is used to characterize the magnitude of the observed displacement. Squaring is to eliminate the influence of positive and negative differences and only focus on the displacement amplitude. Before being substituted into the expression for calculation, the latitude and longitude differences in the numerator need to be converted into Euclidean distance in meters by a projection algorithm to keep the dimensions consistent with the denominator. The most recent reflecting the current moment The drift noise level of satellite signals at a historical moment; the greater the noise, such as from canyons obstructing the signal and causing instability. The larger the value, the more stable the signal; for example, in open areas. The smaller; This means combining the currently observed displacement magnitude with the drift noise level of the satellite signal to determine whether the inspected object is silent or in real motion.

[0035] For example, in scenario one, the object being inspected is stationary but located in a canyon, and statistics are obtained... The observed displacement is 5 meters. Calculate... The spatiotemporal silence index is close to 1, and the system determines that the inspected object is in a silent state. Scenario two exists: the inspected object is in an open area. The observed displacement is 5 meters. Calculate... The spatiotemporal stillness index is close to 0, and the system determines that the inspected object is in a state of significant motion. The above results... Retain to four decimal places.

[0036] It should be noted that simply remaining silent does not equate to absolute safety. In emergency rescue scenarios, abnormal fluctuations in environmental parameters, such as the heart rate of the object being inspected, the temperature of the environment, and gas concentration, are often precursors to danger. Therefore, it is necessary to construct a mathematical model that can calculate the degree of environmental urgency. This model is the core adaptive indicator in the satellite emergency alarm system for determining whether there is danger in the environment of the object being inspected and whether an emergency alarm needs to be activated. It integrates multi-dimensional environmental parameters and historical statistical characteristics, and does not simply rely on the absolute value of a single environmental data point. Instead, it combines the historical mean and standard deviation of each environmental parameter to distinguish between real danger anomalies and false anomalies caused by data fluctuations.

[0037] Preferably, the current alarm urgency coefficient is calculated based on the average abnormal fluctuation degree of different data in the current environmental parameters, including: It should be noted that traditional methods of judging by a single environmental parameter or using fixed threshold alarms cannot accurately reflect the true urgency of an emergency scenario, and are prone to false alarms or missed alarms. The current expression for the alarm urgency coefficient uses the squared standardized deviation of each environmental parameter to represent the degree of anomaly of a single parameter, and uses the average of the anomalies of multiple parameters to comprehensively reflect the overall level of environmental anomalies. Through exponential mapping, the degree of anomaly is transformed from the non-negative real number domain to the range of 0 to 1. This not only accurately calculates the abnormal characteristics of environmental parameters from multiple dimensions, but also achieves a normalized representation of alarm urgency, adapting to the hierarchical judgment requirements of emergency alarm scenarios.

[0038] The current alarm urgency coefficient satisfies the following expression: ; In the formula, This indicates the current alarm urgency level. Indicates the data type in the current environment parameters. The value; This represents the average value of data type j in the current historical environment set; This represents the standard deviation of data type j in the current historical environment set; This refers to the data types in the current environmental parameters; It represents a very small positive number, and guarantees that the denominator is not 0.

[0039] In the formula, This represents the data in the current environmental parameters at the current moment. The square of the standardized deviation is the degree of abnormality of the parameter. Indicating the current environmental parameters at the current moment The mean degree of anomaly in the data; Indicates will The degree of abnormality is mapped to The numerical range.

[0040] S3: Multiply the result of the exponential operation of the difference between the current spatiotemporal silence index and the current alarm urgency coefficient with the current coordinate standard deviation to obtain the current dynamic step size factor; determine the actual maximum displacement based on the sum of the current displacement status of the inspected object and the current coordinate standard deviation, divide it by the current dynamic step size factor to obtain the minimum required number of discrete states, and then perform binary conversion to obtain the current data bit truncation value.

[0041] It should be noted that existing technologies use fixed evaluation accuracy methods, such as keeping a fixed 6 decimal places, which cannot smoothly switch between low-power daily mode and high-precision emergency mode. This invention calculates a dynamic step size by analyzing the above characteristics. This step size determines the granularity of latitude and longitude values, i.e., the current dynamic step size factor. It is an indicator that determines the accuracy of positioning data calculation in satellite emergency alarm systems. It integrates the characteristics of spatiotemporal silence index and alarm urgency coefficient. Instead of using a fixed granularity threshold, it adjusts the physical granularity of positioning data by combining signal noise level and system status.

[0042] Preferably, the current dynamic step size factor is obtained by multiplying the exponential calculation result of the difference between the current spatiotemporal silence index and the current alarm urgency coefficient with the current coordinate standard deviation, including: Calculate the difference between the current spatiotemporal silence index and the current alarm urgency coefficient, and express the difference as a natural constant. Using the base as the base, perform an exponential operation, and multiply the result of the exponential operation by the current coordinate standard deviation to obtain the current dynamic step size factor.

[0043] It should be noted that the current dynamic step size factor indicates that the current dynamic step size depends not only on the current signal-noise level but also on the nonlinear modulation of the system's state. The current coordinate standard deviation serves as a physical reference, ensuring that the dynamic step size remains within the current signal environment. The exponential calculation result acts as a dimensionless state gain factor, used to scale the physical reference. When the time-space silence index approaches 1 and the current alarm urgency coefficient approaches 0, the exponential calculation result is positive, increasing the dynamic step size to obfuscate the data, i.e., increasing the calculation interval of the positioning data. For example, it may increase the original... The accuracy of meters is adjusted to 5 meters, retaining only the approximate range of coordinates to reduce data bit width usage and save satellite bandwidth. When the time-space silence index approaches 0 and the current alarm urgency coefficient approaches 1, the exponent calculation result is negative, compressing the step size to sharpen the data, i.e., reducing the calculation interval of positioning data, such as increasing the accuracy to 0.1 meters, retaining the fine values ​​of coordinates, and ensuring that the positioning information is accurate enough. When the exponent calculation result is negative, the value of the dynamic step size factor will be reduced, rather than generating a negative number, thereby compressing the calculation interval of positioning data. At the same time, it is made clear that the dynamic step size factor is always positive, and the exponent calculation result is only used to adjust its size.

[0044] It should be noted that the current dynamic step size factor only determines the physical granularity of data segmentation. At the digital communication level, it must be converted into a specific binary bit width. This invention aims to accurately calculate the minimum number of bits required to cover the current physical displacement under the current dynamic step size through logarithmic operations, i.e., the current data bit truncation value. It converts the dynamic step size of the physical layer into an indicator of the bit occupancy of the digital communication layer, including the mapping relationship between the current displacement range and the dynamic step size. It does not use a fixed bit width, but combines the physical range to be transmitted and the minimum resolution to calculate the minimum number of bits required to cover the current data.

[0045] Specifically, the actual maximum displacement is determined by the sum of the current displacement status of the inspected object and the current coordinate standard deviation. This is then divided by the current dynamic step size factor to obtain the minimum required number of discrete states, followed by binary conversion to obtain the current data bit truncation value, including: It should be noted that traditional fixed bit allocation or single-parameter driven methods cannot adapt to the dynamic needs of satellite emergency alarm scenarios, which can easily lead to loss of accuracy or waste of bandwidth. The current expression for the data bit truncation value determines the total physical range with noise redundancy by fusing the maximum physical displacement of latitude and longitude with the standard deviation of coordinates. The resolution is adjusted by a dynamic step size factor. The bit number requirement is transformed by a logarithmic operation with base 2, and then rounded up to ensure integer bit output. This not only accurately matches the physical characteristics of the positioning data and the binary communication rules, but also achieves dynamic adaptation of scene status and bandwidth usage.

[0046] The current data bit truncation value satisfies the following expression: ; In the formula, Indicates the current data bit truncation value; This represents the absolute value of the displacement of the current longitude coordinate from the longitude coordinate of the previous time point; This represents the absolute value of the displacement of the current latitude coordinate from the latitude coordinate of the previous moment; This indicates the standard deviation of the current coordinates, in meters. Indicates the current dynamic step size factor; Represents a very small positive number, ensuring that the denominator is not zero; It is a rounding function; Represents a logarithmic function.

[0047] In the formula, This indicates that the larger of the absolute values ​​of longitude and latitude displacement is taken, representing the actual maximum physical displacement of the monitored object. This represents the current coordinate standard deviation, superimposed on the maximum displacement. To allow for noise redundancy, such as in cases where signal drift might cause errors in displacement measurement, this is added... This ensures that the number of bits covers the entire range of actual displacement plus noise; This means dividing the total physical range by the minimum resolution to get the number of independent discrete states required to completely cover the current positioning data. In other words, each discrete state corresponds to one data unit that can be represented by a binary bit. Represented using binary bits Minimum number of bits required for each discrete state; This means rounding up the decimal result of a logarithmic operation to an integer. The number of bits must be an integer, not a decimal.

[0048] For example, the actual displacement is set to 20,000 meters. In the case of meter reading, scenario one exists: the object being inspected is in a silent state. rice, Bit; Scenario 2 exists, the inspected object is in a high-risk state: rice, Bit.

[0049] S4: Take the difference between the current displacement change and the dynamic step size factor and truncate it to generate a position data segment; calculate the remaining available bit space based on the pre-acquired total message space capacity and fill it according to the priority of each data of the current environmental parameters; send a message to perform data status write-back and update historical related data.

[0050] It should be noted that in satellite short message communication, every bit is extremely precious. Traditional methods often cannot send high-precision coordinates and complete environmental situation information at the same time when alarming because the message length is limited. This invention maximizes the information entropy of the short message by dynamically compressing coordinate data and leaving the saved space for environmental data.

[0051] Preferably, the difference between the current displacement change and the dynamic step size factor is taken and truncated to generate a position data segment, including: Calculate the difference between the current latitude and longitude coordinates and the coordinates at the previous time and divide it by the dynamic step size factor. Perform a rounding operation on the obtained quotient and then truncate the rounding result according to the preset number of bits M to generate a position data segment.

[0052] It should be noted that the preset number of bits M is a fixed value pre-configured by the system, and M ≥ the current data bit truncation value, ensuring that the truncated data can cover the current positioning requirements; the main purpose of differential coding is to compress location data to release bandwidth. Under the premise that the length of satellite short messages is fixed, the fewer bits occupied by location data, the more space is left for environmental data. This invention utilizes the valuable bit resources saved in the previous steps to dynamically fill according to the degree of abnormality of environmental parameters, maximizing the information value of a single frame message.

[0053] Specifically, the remaining available bit space is calculated based on the pre-acquired total message space capacity, and then filled according to the priority of each data item in the current environment parameters, including: Obtain the total message space capacity specified by the short message protocol from the satellite parameter system, and subtract the number of bits for the position data segment to obtain the remaining available bits; calculate the standardized deviation of each data of the current environmental parameters; establish a priority queue based on the magnitude of the standardized deviation, and place the data with the largest deviation in the high priority to obtain the environmental parameter queue; according to the remaining available bits, sequentially extract the corresponding data from the environmental parameter queue from high priority to low priority and fill it into the message until the remaining available bits are exhausted.

[0054] It should be noted that the stability of the differential coding system depends on the consistency of the reference between the sender and receiver. If the reference coordinates are updated in the event of a message transmission failure, subsequent message decoding will be incorrect. Statistical features, such as standard deviation, reflect objective physical laws and must be continuously updated. Therefore, this invention designs a separate state update mechanism to ensure the reliability of communication and the real-time performance of the model.

[0055] Preferably, sending a message performs data status write-back and updates historical related data, including: If the message is successfully generated and sent, the current latitude and longitude coordinates will be overwritten into the system's global state context as the coordinates of the previous moment in the next cycle. At the same time, regardless of whether the sending is successful or not, the current latitude and longitude coordinates and the current environmental parameters will be integrated into the current historical coordinate sequence and the current historical environment set, and the oldest data will be removed to form a data loop.

[0056] This completes the emergency alarm system based on satellite communication.

[0057] The present invention also discloses an emergency alarm system based on satellite communication, including a processor and a memory. The memory stores computer program instructions, which, when executed by the processor, implement the emergency alarm method based on satellite communication according to the present invention.

[0058] The system also includes other components well known to those skilled in the art, such as communication buses and communication interfaces, the settings and functions of which are known in the art and will not be described in detail here.

[0059] While this specification has shown and described numerous embodiments of the invention, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of this invention.

Claims

1. An emergency alarm method based on satellite communication, characterized in that, include: The system captures the current latitude and longitude coordinates and current environmental parameters of the inspected object in real time, stores the corresponding data for a preset time period as the current historical coordinate sequence and the current historical environment set; and retrieves the coordinates from the previous moment from the memory. The current spatiotemporal silence index is calculated based on the difference between the displacement magnitude obtained from the current latitude and longitude coordinates and the fluctuation degree of the current historical coordinate sequence; the current alarm urgency coefficient is calculated based on the average abnormal fluctuation degree of different data in the current environmental parameters. The current dynamic step size factor is obtained by multiplying the result of the exponential operation of the difference between the current spatiotemporal silence index and the current alarm urgency coefficient with the current coordinate standard deviation; the actual maximum displacement is determined by the sum of the current displacement status of the inspected object and the current coordinate standard deviation, and then divided by the current dynamic step size factor to obtain the minimum required number of discrete states before binary conversion. The difference between the current displacement change and the dynamic step size factor is taken and truncated to generate a position data segment; The remaining available bit space is calculated based on the total pre-acquired message space capacity, and then filled according to the priority of each data in the current environment parameters. Sending messages executes data status write-back and updates historical related data.

2. The emergency alarm method based on satellite communication according to claim 1, characterized in that, The real-time capture of the current latitude and longitude coordinates and current environmental parameters of the inspected object, and the storage of corresponding data for a preset time period are denoted as the current historical coordinate sequence and the current historical environment set, including: Before the inspected object enters an area without public network coverage, the onboard communication terminal is activated to obtain the current latitude and longitude coordinates in real time, including current environmental parameters such as the inspector's heart rate, ambient temperature, and gas concentration; and the most recently stored data is stored. The current historical coordinate sequence and current historical environment set of each historical moment; retrieve the reference coordinates of the last successful message transmission at the current moment from the local memory, and record them as the coordinates of the previous moment.

3. The emergency alarm method based on satellite communication according to claim 1, characterized in that, The current spatiotemporal silence index satisfies the following expression: ； In the formula, Represents the spatiotemporal silence index, with a range of values. ; Indicates the current latitude and longitude coordinates. This represents the latitude and longitude coordinates of the previous moment, in square meters; Indicates the standard deviation of the current coordinates; It represents a very small positive number, and guarantees that the denominator is not 0.

4. The emergency alarm method based on satellite communication according to claim 1, characterized in that, The current alarm urgency coefficient satisfies the following expression: ； In the formula, This indicates the current alarm urgency level. Indicates the data type in the current environment parameters. The value; This represents the average value of data type j in the current historical environment set; This represents the standard deviation of data type j in the current historical environment set; This refers to the data types in the current environmental parameters; It represents a very small positive number, and guarantees that the denominator is not 0.

5. The emergency alarm method based on satellite communication according to claim 1, characterized in that, Obtaining the current dynamic step size factor includes: Calculate the difference between the current spatiotemporal silence index and the current alarm urgency coefficient. Perform an exponential operation on the difference with the natural constant as the base. Multiply the result of the exponential operation by the current coordinate standard deviation to obtain the current dynamic step size factor.

6. The emergency alarm method based on satellite communication according to claim 1, characterized in that, The current data bit truncation value satisfies the following expression: ； In the formula, Indicates the current data bit truncation value; This represents the absolute value of the displacement of the current longitude coordinate from the longitude coordinate of the previous time point; This represents the absolute value of the displacement of the current latitude coordinate from the latitude coordinate of the previous moment; This indicates the standard deviation of the current coordinates, in meters. Indicates the current dynamic step size factor; Represents a very small positive number, ensuring that the denominator is not zero; It is a rounding function; Represents a logarithmic function.

7. The emergency alarm method based on satellite communication according to claim 1, characterized in that, The generated location data segment includes: Calculate the difference between the current latitude and longitude coordinates and the coordinates at the previous time and divide it by the dynamic step size factor. Perform a rounding operation on the obtained quotient and then truncate the rounding result according to the preset number of bits M to generate a position data segment.

8. The emergency alarm method based on satellite communication according to claim 1, characterized in that, The step of calculating the remaining available bit space based on the pre-acquired total message space capacity and filling it according to the priority of each data in the current environment parameters includes: Obtain the total message space capacity specified by the short message protocol from the satellite parameter system, and subtract the number of bits for the position data segment to obtain the remaining available bits; calculate the standardized deviation of each data of the current environmental parameters; establish a priority queue based on the magnitude of the standardized deviation, and place the data with the largest deviation in the high priority to obtain the environmental parameter queue; according to the remaining available bits, sequentially extract the corresponding data from the environmental parameter queue from high priority to low priority and fill it into the message until the remaining available bits are exhausted.

9. The emergency alarm method based on satellite communication according to claim 1, characterized in that, The process of sending a message, performing data status write-back, and updating historical data includes: If the message is successfully generated and sent, the current latitude and longitude coordinates will be overwritten into the system's global state context as the coordinates of the previous moment in the next cycle. At the same time, regardless of whether the sending is successful or not, the current latitude and longitude coordinates and the current environmental parameters will be integrated into the current historical coordinate sequence and the current historical environment set, and the oldest data will be removed to form a data loop.

10. An emergency alarm system based on satellite communication, characterized in that, include: A processor and a memory, the memory storing computer program instructions that, when executed by the processor, implement the emergency alarm method based on satellite communication according to any one of claims 1-9.

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