An adaptive multi-band radio wave recognition method

Abstract

The present invention relates to the field of radio positioning detection technology, and in particular to an adaptive multi-band radio wave identification method, the method comprising: data monitoring; judging the approaching state of multiple targets; judging the target shielding state; adjusting the frequency band to cope with interference; correcting the threshold and issuing an alarm. The present invention can effectively improve the target recognition accuracy of low-altitude aircraft in a complex electromagnetic environment by combining comprehensive analysis of real-time reflection time delay, reflection cross section and interference ratio, avoids interference problems that a single frequency band is susceptible to by dynamically adjusting the frequency band, enhances the recognition ability of shielded targets, ensures that targets can still be accurately detected in the approaching state of multiple targets and complex shielding conditions, and can effectively avoid the influence of interference sources on the recognition system based on continuous interference pattern recognition and frequency band optimization of real-time data, effectively solving the problem of poor real-time performance and low accuracy of signal recognition due to static signal processing and excessive consumption of computing resources.

Description

Technical Field

[0001] The present invention relates to the technical field of radio positioning detection, and in particular to an adaptive multi-band radio wave recognition method. Background Art

[0002] With the rapid development of low-altitude aircraft, drones and intelligent transportation systems, the demand for target monitoring and identification is increasing. In complex environments, especially in cities, mountainous areas or in severe weather conditions, target identification and tracking become more difficult. This requires more advanced technical support in terms of real-time processing capabilities, anti-interference capabilities and high-precision positioning to ensure that aircraft can safely and accurately identify and respond to surrounding targets and obstacles when performing missions.

[0003] The patent document with publication number CN119024295A discloses a target detection method, device, electronic device and radar detection structure. The method includes: obtaining multiple radar pulse signals obtained by multiple initial calculation units in a brain-like chip based on radar initial signals; transmitting the multiple radar pulse signals to multiple pulse calculation units in the brain-like chip, and processing the signal components in the radar pulse signal by each pulse calculation unit to obtain component detection results; the component parameters of the signal components include time parameters and frequency band parameters, and different component parameters correspond to different pulse calculation units; according to each component detection result, a radar detection result is obtained, and the radar detection result represents whether there is a target object.

[0004] It can be seen that the target detection method has the following problems: the method needs to process the signal components of multiple radar pulse signals, and each pulse calculation unit corresponds to different component parameters, which will result in a large amount of computing resources and a long processing time. Especially in real-time processing applications, it is difficult to meet real-time requirements; in complex or dynamic environments, the reflected signal of the target object may change significantly, and the detection based on static signal component analysis cannot adapt to these changes in time, resulting in inaccurate target detection results. Summary of the invention

[0005] To this end, the present invention provides an adaptive multi-band radio wave identification method, which is used to overcome the problems of poor real-time signal recognition and low accuracy in the prior art due to signal processing staticness and excessive consumption of computing resources by dynamically adjusting frequency bands and analyzing changes in reflected signals in real time.

[0006] To achieve the above object, the present invention provides an adaptive multi-band radio wave identification method, comprising:

[0007] Monitor the real-time reflection time delay, real-time reflection cross section and real-time interference ratio received by low-altitude aircraft at the center of the identification area;

[0008] Wherein, the low-altitude aircraft transmits radio wave signals within a preset frequency band;

[0009] Determining the multi-target approaching state according to the real-time reflection time delay and the preset extended fluctuation threshold;

[0010] Determining the shielding state of the target to be identified in the identification area according to the real-time reflection cross section in the multi-target approach state;

[0011] Determine a continuous interference mode of the occlusion state according to the real-time reflection time delay, the real-time reflection cross section and a preset duration threshold in the occlusion state;

[0012] Adjusting the preset frequency band according to the continuous interference mode and the real-time interference ratio to form an adjusted frequency band;

[0013] The low-altitude aircraft transmits a radio wave signal within the adjustment frequency band, and corrects the preset extended fluctuation threshold according to the number of shielding states formed based on the adjustment frequency band within a preset correction time;

[0014] Determine a plurality of the targets to be identified in a multi-target approach state based on the modified preset extended fluctuation threshold value to form an identified target;

[0015] An alarm is issued based on the identified target.

[0016] Further, determining the multi-target approaching state according to the real-time reflection time delay and the preset extended fluctuation threshold comprises:

[0017] When the real-time reflection time delay is less than a preset delay threshold, calculating a standard deviation of the real-time reflection time delay within a preset first determined time length to form an extended fluctuation value;

[0018] The multi-target approach state is determined according to the extended fluctuation value and the preset extended fluctuation threshold.

[0019] Further, the determining the multi-target approaching state according to the extended fluctuation value and the preset extended fluctuation threshold comprises:

[0020] When the extended fluctuation value is greater than the preset extended fluctuation threshold, it is determined that there is a multi-target approach state.

[0021] Further, the determining the shielding state of the target to be identified in the identification area according to the real-time reflection cross section in the multi-target approaching state includes:

[0022] Calculate the standard deviation of the real-time reflection cross section within a preset second determined time period to form a cross-section fluctuation value;

[0023] When the cross-sectional fluctuation value is greater than a preset cross-sectional fluctuation threshold, it is determined that the target to be identified is in an obstructed state.

[0024] Further, the determining of the continuous interference mode of the occlusion state according to the real-time reflection time delay, the real-time reflection cross section and a preset duration threshold in the occlusion state includes:

[0025] Draw a variation curve of the real-time reflection time delay within a preset drawing time length to form a delay curve;

[0026] Drawing a change curve of the reflection cross section within the preset drawing time to form a cross-section curve;

[0027] The continuous interference mode of the blocking state is determined according to the delay curve, the cross-section curve and the preset duration threshold.

[0028] Further, the determining the continuous interference mode of the occlusion state according to the delay curve, the cross-section curve and the preset duration threshold includes:

[0029] Calculating the cosine similarity of the delay curve and the cross-section curve to form a change consistency;

[0030] When the change consistency is less than a preset consistency threshold, determining that there is interference in the occlusion state;

[0031] When the duration of the interference situation is greater than the preset duration threshold, the interference mode of the shielding state is determined to be a continuous interference mode.

[0032] Further, adjusting the preset frequency band according to the continuous interference mode and the real-time interference ratio includes:

[0033] When the real-time interference ratio is greater than a preset interference ratio threshold, the preset frequency band is reduced according to the real-time interference ratio and the preset interference ratio threshold.

[0034] Further, the narrowing of the preset frequency band according to the real-time interference ratio and the preset interference ratio threshold comprises:

[0035] The minimum frequency in the preset frequency band is increased according to a relative deviation between the real-time interference ratio and the preset interference ratio threshold and a preset adjustment coefficient.

[0036] Further, when the extended fluctuation value is less than or equal to the preset extended fluctuation threshold, it is determined that a single target approaching state exists, and an alarm is issued according to the target to be identified in the single target approaching state.

[0037] Further, the step of correcting the preset extended fluctuation threshold according to the number of occlusion states formed based on the adjustment frequency band within the preset correction time period includes:

[0038] Calculating the standard deviation of the quantity to form an occlusion quantity fluctuation value;

[0039] When the occlusion quantity fluctuation value is greater than the preset quantity fluctuation threshold, the preset extended fluctuation threshold is increased according to the relative deviation between the occlusion quantity fluctuation value and the preset quantity fluctuation threshold and a preset correction coefficient.

[0040] Compared with the prior art, the beneficial effect of the present invention lies in that, by combining the comprehensive analysis of real-time reflection time delay, reflection cross section and interference ratio, the target recognition accuracy of low-altitude aircraft can be effectively improved in a complex electromagnetic environment. By dynamically adjusting the frequency band, the interference problem that a single frequency band is susceptible to is avoided, and the recognition ability of obscured targets is enhanced, ensuring that targets can still be accurately detected in multiple target approaching states and complex obstruction conditions. Continuous interference pattern recognition and frequency band optimization based on real-time data can effectively avoid the influence of interference sources on the recognition system, thereby improving the stability and reliability of target detection. By correcting the fluctuations in the number of obstruction states, the recognition sensitivity can be adaptively adjusted, and more efficient and accurate target recognition can be achieved in a changing flight environment, thereby improving the operational safety and autonomy of the aircraft in a complex and dynamic environment, and effectively solving the problems of poor real-time and low accuracy of signal recognition due to signal processing staticness and excessive consumption of computing resources.

[0041] Furthermore, by analyzing the fluctuation of the reflection time delay, we can ensure accurate judgment of targets in complex flight environments. When multiple targets are approaching, we can identify and respond accordingly, thereby improving the aircraft's monitoring ability of surrounding targets. Through real-time fluctuation analysis, we can improve the sensitivity to the proximity of targets.

[0042] Furthermore, through the change curve of time delay and reflection cross section, the interference can be monitored and analyzed in real time, so as to effectively distinguish between instantaneous interference and continuous interference.

[0043] Furthermore, by calculating the cosine similarity of the delay curve and the cross-sectional curve, the interference pattern under the occlusion state can be effectively determined, and by monitoring the duration of the interference, instantaneous interference and continuous interference can be accurately distinguished.

[0044] Furthermore, by adjusting the frequency band according to the change of real-time interference ratio, it can dynamically respond to the change of interference environment, avoid being affected by interference when the frequency band is too high, and improve the stability and accuracy of signal processing. In addition, reducing the use of frequency bands can effectively improve the utilization efficiency of spectrum resources, so that low-altitude aircraft can better identify targets and suppress interference in complex environments.

[0045] Furthermore, by calculating the cosine similarity of the delay curve and the cross-sectional curve, the interference pattern under the occlusion state can be effectively determined, and by monitoring the duration of the interference, instantaneous interference and continuous interference can be accurately distinguished.

[0046] Furthermore, by adjusting the frequency band according to the change of real-time interference ratio, it can dynamically respond to the change of interference environment, avoid being affected by interference when the frequency band is too high, and improve the stability and accuracy of signal processing. In addition, reducing the use of frequency bands can effectively improve the utilization efficiency of spectrum resources, so that low-altitude aircraft can better identify targets and suppress interference in complex environments.

[0047] Furthermore, increasing the minimum frequency can effectively avoid strong interference in the low frequency band, because the low frequency band is more sensitive to interference, and interference signals can easily affect the system's signal processing and target recognition capabilities. By increasing only the minimum frequency, it is possible to avoid adjusting the frequency band over a large range, thereby maintaining the stability of the overall frequency band and the operating efficiency of the system, while reducing the impact of interference and improving recognition accuracy and system performance.

[0048] Furthermore, by introducing a preset extended fluctuation threshold, it is possible to accurately identify and respond to the approach of a single target, avoid false alarms in the case of interference from multiple targets, and improve the accuracy and timeliness of the alarm.

[0049] Furthermore, by dynamically correcting the fluctuations in the number of occlusion states, it ensures that high accuracy and stability can be maintained even when the environment changes greatly. By adjusting the preset extended fluctuation threshold, it can better cope with changes in target occlusion and improve the accuracy and flexibility of target recognition. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a flow chart of the adaptive multi-band radio wave identification method of this embodiment;

[0051] Figure 2 A decision logic diagram for extending the fluctuation value is formed for this embodiment;

[0052] Figure 3 A decision logic diagram for determining the approaching state of multiple targets in this embodiment;

[0053] Figure 4 The decision logic diagram for determining the continuous interference mode in this embodiment. DETAILED DESCRIPTION

[0054] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0055] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0056] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0057] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] See also Figure 1 As shown, it is a flow chart of the adaptive multi-band radio wave identification method of this embodiment;

[0059] This embodiment provides an adaptive multi-band radio wave identification method, including:

[0060] Monitor the real-time reflection time delay, real-time reflection cross section and real-time interference ratio received by low-altitude aircraft at the center of the identification area;

[0061] Wherein, the low-altitude aircraft transmits radio wave signals within a preset frequency band;

[0062] Determining the multi-target approaching state according to the real-time reflection time delay and the preset extended fluctuation threshold;

[0063] Determining the shielding state of the target to be identified in the identification area according to the real-time reflection cross section in the multi-target approach state;

[0064] Determine a continuous interference mode of the occlusion state according to the real-time reflection time delay, the real-time reflection cross section and a preset duration threshold in the occlusion state;

[0065] Adjusting the preset frequency band according to the continuous interference mode and the real-time interference ratio to form an adjusted frequency band;

[0066] The low-altitude aircraft transmits a radio wave signal within the adjustment frequency band, and corrects the preset extended fluctuation threshold according to the number of shielding states formed based on the adjustment frequency band within a preset correction time;

[0067] Determine a plurality of the targets to be identified in a multi-target approach state based on the modified preset extended fluctuation threshold value to form an identified target;

[0068] An alarm is issued based on the identified target.

[0069] Real-time reflection time delay refers to the time difference that a low-altitude aircraft experiences when receiving a radio signal reflected from a target object. Specifically, after the aircraft transmits a radio signal, the signal will reflect off the target and return to the aircraft receiver. By accurately measuring the time interval from the transmission to the reception of the signal, the system can calculate the distance between the target and the aircraft. The reflection time delay changes dynamically in real time, so it can reflect the real-time changes in the target position and help the aircraft determine the distance and motion status of the target.

[0070] The real-time reflection cross section (RCS) is an important parameter to measure the target's ability to reflect radio wave signals. It indicates the reflection intensity of the target object for the incident radio wave, which is equivalent to the effective "area" of the radio wave signal reflected back by the target. By analyzing the intensity and characteristics of the reflected signal, the reflection cross section of the target can be calculated, and then the shape, size, material properties and other information of the target can be inferred. Targets with larger RCS values ​​usually have stronger reflection capabilities, while small or stealth targets may have lower reflection cross sections. Changes in the real-time reflection cross section help identify whether the target is obscured or has undergone morphological changes.

[0071] The real-time interference ratio refers to the intensity ratio between the effective signal received by the aircraft and the background noise signal. Specifically, the signal received by the aircraft includes not only the reflected wave from the target, but may also be interfered by other electromagnetic signals in the surrounding environment, such as radar interference, signals from other aircraft, etc. The interference ratio reflects the clarity and interference level of the signal by comparing the intensity of the target signal with the noise signal. When the interference ratio is high, it means that the signal is clearer and the interference is less; conversely, a low interference ratio means that the signal may be subject to greater interference, affecting the accuracy of target recognition. Monitoring the real-time interference ratio helps adjust the frequency band and optimize signal processing to improve the reliability of target recognition.

[0072] The preset duration threshold is the time length threshold used by the system to determine whether the interference of the occlusion state reaches the continuous interference mode. It depends on the characteristics of the interference mode, the response requirements of the system, environmental factors and the required accuracy. It is usually set between several seconds and tens of seconds. In this embodiment, it is set to 5 seconds, which can quickly identify and respond to the continuous interference of the occlusion state, avoid slow system response due to too long time, and ensure accurate judgment of the interference mode.

[0073] The preset extended fluctuation threshold is used to determine whether the reflection time delay fluctuation reaches the standard value of the multi-target approach state, which depends on the reflection signal fluctuation characteristics of the system and the expected target approach mode, and is usually set between 5% and 20% according to the actual flight environment and signal quality. In this embodiment, it is set to 10%, which helps to balance sensitivity and anti-interference ability in practical applications and avoid misjudgment of the multi-target approach state.

[0074] The preset frequency band refers to the frequency range used by low-altitude aircraft in the process of radio wave identification. It depends on the environmental characteristics, target characteristics and equipment performance. It is usually set between several hundred MHz and several GHz. In this embodiment, it is set to between 1GHz and 5 GHz. It can provide sufficient resolution to identify different types of targets and effectively avoid the strong interference that may occur in the lower frequency bands, thereby ensuring the efficient operation of the system in complex environments.

[0075] In this embodiment, the real-time reflection time delay, real-time reflection cross section and real-time interference ratio received by the low-altitude aircraft at the center of the monitoring identification area are mainly achieved by installing a high-performance radar system and signal processing unit on the low-altitude aircraft, by transmitting radio wave signals and receiving echo signals reflected from the target, and calculating the time delay of the reflected echo in real time, thereby determining the position and distance of the target. The reflection cross section evaluates the radar reflection capability of the target by analyzing the intensity and characteristics of the echo signal. The real-time interference ratio monitors the level of electromagnetic interference by comparing the intensity of the received effective signal with the background noise signal. Through the precise collection and processing of these real-time data, the system can continuously monitor the state changes of the targets in the identification area, and provide basic data support for subsequent frequency band adjustment and target identification.

[0076] By real-time monitoring of the reflection time delay, reflection cross section and interference ratio received by low-altitude aircraft, radio wave signals are emitted within the preset frequency band to identify and judge the target's obstruction state, approach state and interference mode. When multiple targets are approaching, by analyzing the changes in the reflection cross section, it is possible to identify whether the target is obstructed and the intensity or type of obstruction. At the same time, based on the changes in the real-time interference ratio, the frequency band can be adjusted to optimize signal transmission and ensure more accurate target identification. Finally, through statistical analysis of the number of obstruction states, the fluctuation threshold is corrected to further improve the recognition accuracy and stability.

[0077] By combining the comprehensive analysis of real-time reflection time delay, reflection cross section and interference ratio, the target recognition accuracy of low-altitude aircraft can be effectively improved in complex electromagnetic environments. By dynamically adjusting the frequency band, the interference problem that a single frequency band is susceptible to is avoided, and the ability to recognize obscured targets is enhanced, ensuring that targets can still be accurately detected in multiple target proximity and complex obstruction situations. Continuous interference pattern recognition and frequency band optimization based on real-time data can effectively avoid the impact of interference sources on the recognition system, thereby improving the stability and reliability of target detection. By correcting the fluctuations in the number of obstruction states, the recognition sensitivity can be adaptively adjusted to achieve more efficient and accurate target recognition in a changing flight environment, improving the operational safety and autonomy of aircraft in complex and dynamic environments, and effectively solving the problems of poor real-time and low accuracy of signal recognition due to signal processing staticness and excessive consumption of computing resources.

[0078] Please continue reading Figure 2 As shown, it is a decision logic diagram for forming an extended fluctuation value in this embodiment;

[0079] Specifically, determining the multi-target approaching state according to the real-time reflection time delay and the preset extended fluctuation threshold comprises:

[0080] When the real-time reflection time delay is less than a preset delay threshold, calculating a standard deviation of the real-time reflection time delay within a preset first determined time length to form an extended fluctuation value;

[0081] The multi-target approach state is determined according to the extended fluctuation value and the preset extended fluctuation threshold.

[0082] The preset delay threshold is used to determine whether the reflection time delay exceeds the set standard value, thereby determining whether to initiate further analysis. It depends on the detection capability of the aircraft, the target distance, and the signal propagation characteristics. It is usually set between a few milliseconds and tens of milliseconds. In this embodiment, it is set to 5 milliseconds, which can ensure a rapid response to the approach of the target within the normal flight distance while avoiding misjudgment caused by signal fluctuations.

[0083] By monitoring the real-time reflection time delay received by the low-altitude aircraft, when the delay is less than the preset delay threshold, the system begins to analyze the multi-target approach status. First, the standard deviation of the real-time reflection time delay within the preset first determined time length is calculated to obtain the extension fluctuation value. Then, the extension fluctuation value is compared with the preset extension fluctuation threshold. If the extension fluctuation value exceeds the preset threshold, it is determined to be a multi-target approach state. This process evaluates the proximity of the target by analyzing the delay fluctuation, helping the system to identify whether there are multiple targets approaching the aircraft at the same time.

[0084] By analyzing the fluctuation of reflection time delay, we can ensure accurate judgment of targets in complex flight environments. When multiple targets are approaching, we can identify and respond accordingly, thereby improving the aircraft's monitoring ability of surrounding targets. Through real-time fluctuation analysis, we can improve the sensitivity to the proximity of targets.

[0085] Please continue reading Figure 3 As shown, it is a decision logic diagram for determining the approaching state of multiple targets in this embodiment;

[0086] Specifically, determining the multi-target approach state according to the extended fluctuation value and the preset extended fluctuation threshold includes:

[0087] When the extended fluctuation value is greater than the preset extended fluctuation threshold, it is determined that there is a multi-target approach state.

[0088] First, the extended fluctuation value of the real-time reflection time delay is calculated, that is, the fluctuation of the time delay within the preset determined time length. If the extended fluctuation value is greater than the preset extended fluctuation threshold, the system determines that there are multiple targets approaching the aircraft. This process compares the fluctuation of the actual reflection time delay with the preset threshold to identify whether there are multiple targets approaching the aircraft.

[0089] By distinguishing between the approaching states of single targets and multiple targets, the ability to identify multiple targets in complex flight environments can be improved. By extending the comparison between the fluctuation value and the threshold, it can be used to accurately determine in real time whether there are multiple targets approaching, thereby avoiding misjudgment and missed judgment, and ensuring the safety and monitoring capabilities of the aircraft in a multi-target environment.

[0090] Specifically, determining the shielding state of the target to be identified in the identification area according to the real-time reflection cross section in the multi-target approach state includes:

[0091] Calculate the standard deviation of the real-time reflection cross section within a preset second determined time period to form a cross-section fluctuation value;

[0092] When the cross-sectional fluctuation value is greater than a preset cross-sectional fluctuation threshold, it is determined that the target to be identified is in an obstructed state.

[0093] The preset cross-sectional fluctuation threshold is a reference standard for determining whether a target is in an obstructed state, and depends on factors such as the reflective characteristics of the target, environmental interference, and the detection capability of the aircraft, and is usually set between 0.1 dB and 10 dB. In this embodiment, it is set to 2 dB, which aims to balance the recognition sensitivity of the obstructed state and avoid misjudgment, and can accurately determine the obstructed state while avoiding misjudgment caused by too low a threshold and missed judgment caused by too high a threshold, thereby improving the accuracy and real-time performance of recognition.

[0094] When multiple targets are approaching, the standard deviation of the real-time reflection cross section is calculated to obtain the cross-section fluctuation value, which indicates the degree of change of the target's reflection signal. Subsequently, the fluctuation value is compared with the preset cross-section fluctuation threshold. If the cross-section fluctuation value is greater than the preset threshold, the target is determined to be in an obstructed state. This process helps identify whether the target is obstructed by other objects or environmental factors, thereby affecting the strength and quality of the reflection signal.

[0095] By detecting whether the target is in an obstructed state, the system can ensure the accuracy and reliability of target detection. Through real-time reflection cross-section fluctuation analysis, the system can quickly identify the obstruction situation, thereby adjusting the aircraft's identification strategy, improving target tracking and identification in a multi-target environment, and avoiding misidentification or misjudgment due to obstruction.

[0096] Specifically, determining the continuous interference mode of the occlusion state according to the real-time reflection time delay, the real-time reflection cross section and a preset duration threshold in the occlusion state includes:

[0097] Draw a variation curve of the real-time reflection time delay within a preset drawing time length to form a delay curve;

[0098] Drawing a change curve of the reflection cross section within the preset drawing time to form a cross-section curve;

[0099] The continuous interference mode of the blocking state is determined according to the delay curve, the cross-section curve and the preset duration threshold.

[0100] In the occlusion state, by drawing the change curves of the real-time reflection time delay and the real-time reflection cross section within the preset drawing time, a delay curve and a cross-section curve are formed respectively. These curves reflect the time delay and reflection signal changes of the target in the occlusion state. By analyzing the shape, change trend and correlation of these two curves, the system can determine whether there is a continuous interference pattern, that is, whether the interference caused by the target occlusion persists, and further analyze its impact.

[0101] Through the change curve of time delay and reflection cross section, the interference can be monitored and analyzed in real time, so as to effectively distinguish between instantaneous interference and continuous interference.

[0102] Please continue reading Figure 4 As shown, it is a decision logic diagram for determining the continuous interference mode in this embodiment;

[0103] Specifically, determining the continuous interference mode of the occlusion state according to the delay curve, the cross-section curve and the preset duration threshold includes:

[0104] Calculating the cosine similarity of the delay curve and the cross-section curve to form a change consistency;

[0105] When the change consistency is less than a preset consistency threshold, determining that there is interference in the occlusion state;

[0106] When the duration of the interference situation is greater than the preset duration threshold, the interference mode of the shielding state is determined to be a continuous interference mode.

[0107] The duration of the interference situation refers to the time interval from the first occurrence of interference (i.e., the beginning of the interference of the occlusion state) to the end of the interference situation (i.e., the occlusion state returns to normal or no longer interferes).

[0108] The preset consistency threshold is a standard value used to judge the similarity between the delay curve and the cross-sectional curve. It depends on the signal characteristics of the target, the working environment of the aircraft and the characteristics of the interference source. It is usually set between 0.7 and 0.9. In this embodiment, it is set to 0.8, which can effectively distinguish between normal target changes and abnormal fluctuations caused by interference, thereby more accurately judging the interference situation and ensuring accurate identification of the interference pattern.

[0109] In the occlusion state, the cosine similarity of the delay curve and the cross-section curve is first calculated to obtain the change consistency. The change consistency is used to measure the consistency of the two curves in time change. If the consistency is lower than the preset consistency threshold, it means that there is interference. Furthermore, if the duration of the interference situation exceeds the preset duration threshold, the interference mode of the occlusion state is determined to be a continuous interference mode, which provides a basis for subsequent frequency band adjustment and target identification.

[0110] By calculating the cosine similarity of the delay curve and the cross-sectional curve, the interference pattern under the occlusion state can be effectively determined. By monitoring the duration of the interference, instantaneous interference and continuous interference can be accurately distinguished.

[0111] Specifically, adjusting the preset frequency band according to the continuous interference mode and the real-time interference ratio includes:

[0112] When the real-time interference ratio is greater than a preset interference ratio threshold, the preset frequency band is reduced according to the real-time interference ratio and the preset interference ratio threshold.

[0113] The preset interference ratio threshold is a standard value used to determine whether a signal is interfered with. It depends on factors such as the system's anti-interference capability, the degree of interference in the working environment, and the characteristics of the target signal. It is usually set between 0.2 and 0.8. In this embodiment, it is set to 0.5, which can achieve a good balance between the interference level and signal stability. When the environmental interference is strong, the frequency band can be adjusted in time to effectively avoid signal loss or recognition errors, thereby improving recognition accuracy and the system's anti-interference capability.

[0114] After identifying a continuous interference pattern, if the real-time interference ratio is greater than the preset interference ratio threshold, the system determines whether to adjust the frequency band by comparing the deviation between the real-time interference ratio and the preset interference ratio threshold. If the real-time interference ratio is higher than the preset threshold, it means that the current frequency band may be subject to strong interference. The system will appropriately reduce the frequency range of the preset frequency band according to the relative difference in the interference ratio to reduce signal interference and optimize the target recognition and tracking performance.

[0115] By adjusting the frequency band according to the change of real-time interference ratio, the system can dynamically respond to the change of interference environment, avoid being affected by interference when the frequency band is too high, and improve the stability and accuracy of signal processing. In addition, reducing the use of frequency bands can effectively improve the utilization efficiency of spectrum resources, so that low-altitude aircraft can better identify targets and suppress interference in complex environments.

[0116] Specifically, the narrowing of the preset frequency band according to the real-time interference ratio and the preset interference ratio threshold includes:

[0117] The minimum frequency in the preset frequency band is increased according to a relative deviation between the real-time interference ratio and the preset interference ratio threshold and a preset adjustment coefficient.

[0118] The preset adjustment coefficient is a parameter used to adjust the minimum frequency according to the relative deviation between the real-time interference ratio and the preset interference ratio threshold, and is used to control the amplitude of the frequency adjustment. It depends on the design requirements of the system, the target recognition accuracy, and the amplitude of the change in the interference situation. It is usually set between 0.1 and 1.0. In this embodiment, it is set to 0.3, which can effectively reduce the interference effect while avoiding excessive adjustment of the frequency band, thereby optimizing the target recognition accuracy and improving the robustness of the system.

[0119] The real-time interference ratio directly affects the adjustment of the preset frequency band. When the interference ratio is too high, it may indicate that the interference in the current frequency band is too strong, thus affecting the signal quality and recognition accuracy. Therefore, in order to reduce interference and improve recognition accuracy, it is necessary to adjust the preset frequency band according to the change of the real-time interference ratio and select a clearer frequency band to reduce the impact of interference. According to the relative deviation between the real-time interference ratio and the preset interference ratio threshold, combined with the preset adjustment coefficient, the minimum frequency in the preset frequency band is increased. When the real-time interference ratio is greater than the preset interference ratio threshold, the system will calculate the deviation between the real-time interference ratio and the preset interference ratio threshold, and adjust the frequency band parameters according to the preset adjustment coefficient, thereby increasing the minimum frequency. This adjustment helps to optimize signal transmission and reduce the impact of interference on system performance.

[0120] Increasing the minimum frequency can effectively avoid strong interference in the low frequency band, because the low frequency band is more sensitive to interference, and interference signals can easily affect the system's signal processing and target recognition capabilities. By increasing only the minimum frequency, you can avoid adjusting the frequency band over a large range, thereby maintaining the stability of the overall frequency band and the operating efficiency of the system, while reducing the impact of interference, improving recognition accuracy and system performance.

[0121] Specifically, when the extended fluctuation value is less than or equal to the preset extended fluctuation threshold, it is determined that a single target approaching state exists, and an alarm is issued according to the target to be identified in the single target approaching state.

[0122] When the extended fluctuation value is less than or equal to the preset extended fluctuation threshold, the system determines that a single target is approaching. At this time, the target to be identified is analyzed according to the state, and when the target is confirmed to be approaching, the corresponding alarm mechanism is triggered to warn the operator.

[0123] By introducing a preset extended fluctuation threshold, it is possible to accurately identify and respond to the approach of a single target, avoid false alarms in the event of interference from multiple targets, and improve the accuracy and timeliness of the alarm.

[0124] Specifically, the step of modifying the preset extended fluctuation threshold according to the number of occlusion states formed based on the adjustment frequency band within the preset correction time period includes:

[0125] Calculating the standard deviation of the quantity to form an occlusion quantity fluctuation value;

[0126] When the occlusion quantity fluctuation value is greater than the preset quantity fluctuation threshold, the preset extended fluctuation threshold is increased according to the relative deviation between the occlusion quantity fluctuation value and the preset quantity fluctuation threshold and a preset correction coefficient.

[0127] The preset quantity fluctuation threshold is a parameter used to determine whether the change in the number of occlusion states exceeds the normal fluctuation range. It depends on the system's prediction of the normal environmental fluctuation range and the expected sensitivity. It is generally set between 5% and 15%. In this embodiment, it is set to 10%, which can better balance the recognition of normal fluctuations and abnormal fluctuations, avoid excessive adjustments, and effectively respond to larger changes in occlusion states.

[0128] The preset correction factor is a multiple used to adjust the extended fluctuation threshold. It depends on the system's prediction accuracy of environmental fluctuations and the required sensitivity adjustment range. It is usually set between 1.2 and 2.0. In this embodiment, it is set to 1.5. It can maintain a relatively balanced adjustment range while responding to environmental fluctuations, avoid unnecessary adjustments caused by over-correction, and improve recognition accuracy and system stability.

[0129] Within the preset correction time, the number of occlusion states formed by the adjustment frequency band is corrected. First, the standard deviation of the number of occlusion states is calculated to form an occlusion number fluctuation value. If the fluctuation value is greater than the preset number fluctuation threshold, the preset extended fluctuation threshold is increased according to the relative deviation between the occlusion number fluctuation value and the preset threshold and the preset correction coefficient, thereby adjusting the target recognition and processing strategy.

[0130] By dynamically correcting the fluctuations in the number of occlusion states, it ensures that high accuracy and stability can be maintained even when the environment changes greatly. By adjusting the preset extension fluctuation threshold, it can better cope with changes in target occlusion and improve the accuracy and flexibility of target recognition.

[0131] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0132] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An adaptive multi-band radio wave identification method, characterized in that: include: Monitor the real-time reflection time delay, real-time reflection cross section and real-time interference ratio received by low-altitude aircraft at the center of the identification area; Wherein, the low-altitude aircraft transmits radio wave signals within a preset frequency band; Determining the multi-target approaching state according to the real-time reflection time delay and the preset extended fluctuation threshold; Determining the shielding state of the target to be identified in the identification area according to the real-time reflection cross section in the multi-target approach state; Determine a continuous interference mode of the occlusion state according to the real-time reflection time delay, the real-time reflection cross section and a preset duration threshold in the occlusion state; Adjusting the preset frequency band according to the continuous interference mode and the real-time interference ratio to form an adjusted frequency band; The low-altitude aircraft transmits a radio wave signal within the adjustment frequency band, and corrects the preset extended fluctuation threshold according to the number of shielding states formed based on the adjustment frequency band within a preset correction time; Determine a plurality of the targets to be identified in a multi-target approach state based on the modified preset extended fluctuation threshold value to form an identified target; An alarm is issued based on the identified target.

2. The adaptive multi-band radio wave identification method according to claim 1, characterized in that: Determining the multi-target approaching state according to the real-time reflection time delay and the preset extended fluctuation threshold comprises: When the real-time reflection time delay is less than a preset delay threshold, calculating a standard deviation of the real-time reflection time delay within a preset first determined time length to form an extended fluctuation value; The multi-target approach state is determined according to the extended fluctuation value and the preset extended fluctuation threshold.

3. The adaptive multi-band radio wave identification method according to claim 2, characterized in that: Determining the multi-target approach state according to the extended fluctuation value and the preset extended fluctuation threshold comprises: When the extended fluctuation value is greater than the preset extended fluctuation threshold, it is determined that there is a multi-target approach state.

4. The adaptive multi-band radio wave identification method according to claim 3, characterized in that: The determining of the shielding state of the target to be identified in the identification area according to the real-time reflection cross section in the multi-target approach state comprises: Calculate the standard deviation of the real-time reflection cross section within a preset second determined time period to form a cross-section fluctuation value; When the cross-sectional fluctuation value is greater than a preset cross-sectional fluctuation threshold, it is determined that the target to be identified is in an obstructed state.

5. The adaptive multi-band radio wave identification method according to claim 4, characterized in that: The method of determining the continuous interference mode of the blocking state according to the real-time reflection time delay, the real-time reflection cross section and a preset duration threshold in the blocking state includes: Draw a variation curve of the real-time reflection time delay within a preset drawing time length to form a delay curve; Drawing a change curve of the reflection cross section within the preset drawing time to form a cross-section curve; The continuous interference mode of the blocking state is determined according to the delay curve, the cross-section curve and the preset duration threshold.

6. The adaptive multi-band radio wave identification method according to claim 5, characterized in that: The continuous interference mode of determining the blocking state according to the delay curve, the cross-section curve and the preset duration threshold comprises: Calculating the cosine similarity of the delay curve and the cross-section curve to form a change consistency; When the change consistency is less than a preset consistency threshold, determining that there is interference in the occlusion state; When the duration of the interference situation is greater than the preset duration threshold, the interference mode of the shielding state is determined to be a continuous interference mode.

7. The adaptive multi-band radio wave identification method according to claim 6, characterized in that: The adjusting the preset frequency band according to the continuous interference mode and the real-time interference ratio comprises: When the real-time interference ratio is greater than a preset interference ratio threshold, the preset frequency band is reduced according to the real-time interference ratio and the preset interference ratio threshold.

8. The adaptive multi-band radio wave identification method according to claim 7, characterized in that: The narrowing of the preset frequency band according to the real-time interference ratio and the preset interference ratio threshold comprises: The minimum frequency in the preset frequency band is increased according to a relative deviation between the real-time interference ratio and the preset interference ratio threshold and a preset adjustment coefficient.

9. The adaptive multi-band radio wave identification method according to claim 8, characterized in that: When the extended fluctuation value is less than or equal to the preset extended fluctuation threshold, it is determined that a single target approaching state exists, and an alarm is issued according to the target to be identified in the single target approaching state.

10. The adaptive multi-band radio wave identification method according to claim 9, characterized in that: The step of modifying the preset extended fluctuation threshold according to the number of occlusion states formed based on the adjustment frequency band within the preset modification time period includes: Calculating the standard deviation of the quantity to form an occlusion quantity fluctuation value; When the occlusion quantity fluctuation value is greater than the preset quantity fluctuation threshold, the preset extended fluctuation threshold is increased according to the relative deviation between the occlusion quantity fluctuation value and the preset quantity fluctuation threshold and a preset correction coefficient.

Images