Distributed multi-infrared sensor collaborative guidance search and target identity determination method

Abstract

The present application belongs to the field of distributed passive sensor collaborative guidance search and detection technology. The present application provides a distributed multi-infrared sensor collaborative guidance search and target identity determination method. The disclosed embodiment utilizes the designed collaborative guidance method to dynamically formulate the optimal search sector and strategy of the non-reference sensor based on the two-dimensional observation information of the target by the reference sensor, and dynamically adjusts the search sector by combining its own and the target observation information, and collaboratively guides the non-reference sensors at different node positions to point to the target, thereby reducing the target search time and improving the overall detection efficiency. At the same time, in the collaborative search stage, the identity determination of the target observed by multiple infrared sensors is completed based on the two-dimensional observation information, and then the capture of the target is achieved, providing effective support for the tracking and positioning of the target in the distributed network detection scenario, and improving the positioning accuracy of the distributed multi-infrared sensor network detection system.

Description

Technical Field

[0001] The disclosed embodiments relate to the technical field of distributed passive sensor collaborative guidance search and detection, and in particular to a distributed multi-infrared sensor collaborative guidance search and target identity determination method. Background Art

[0002] Long-distance, all-round, large-airspace, and highly concealed detection have become the goals pursued by future identification and detection systems. As a passive sensor, infrared sensors detect targets by detecting the thermal infrared radiation of targets and do not actively emit electromagnetic waves. They have the characteristics of long detection distance and high concealment. At the same time, due to their passive working characteristics, they will not be interfered with or affected by electromagnetic confrontations such as radio frequency clutter.

[0003] A single infrared sensor can only obtain the angle information of the target, but not the distance information. It cannot accurately locate and track the target, especially the moving target, like active sensors such as radar. At the same time, due to the detection accuracy requirements, the narrow field of view of the infrared sensor is usually small (±0.5 degrees to ±5 degrees). The individual capabilities of a single sensor are insufficient and cannot meet the needs of all-round and large airspace situational awareness. Through the distributed networking detection of the target by multiple infrared sensors arranged at different sensing nodes, the nodes exchange status information, decision information and sensor data, and according to certain coordination strategies and data fusion strategies, it is possible to accurately locate and track the moving target; at the same time, the multiple sensors in the distributed layout have the characteristics of spatial distribution, functional distribution, time distribution, information distribution, resource distribution, etc., which can meet the requirements of all-round and large airspace situational awareness.

[0004] However, due to the small narrow field of view of infrared sensors, when multiple sensors at different sensing nodes use established search strategies to search for targets, they cannot guarantee that suspicious targets in a certain airspace will be detected at the same time, and then the precise positioning and capture and tracking of the designated target cannot be achieved. In practical applications, the narrow field of view of the infrared sensor located at a certain node must first discover the suspicious target, and then guide the remaining sensors to quickly aim at the suspicious target through a collaborative guidance search strategy. Existing research on distributed sensor collaborative guidance search strategies is mostly aimed at active sensors such as radars or passive sensors assisted by other ranging sensors. Since a single infrared sensor cannot obtain the position of the target in space like active sensors such as radars, the traditional distributed collaborative guidance search strategy of active sensors is not suitable for infrared sensors that lack distance detection information.

[0005] In addition, the problem of target identity determination is a key issue that needs to be urgently solved in distributed multi-sensor network collaborative detection. Its purpose is to establish a one-to-one correspondence between multiple targets observed by multiple sensors. However, the current identity determination steps of distributed multi-sensor network detection all assume that there are the same or different numbers of targets in the wide field of view of the distributed multi-sensor joint detection. When completing the target identity determination in the wide field of view, the sensor angular measurement error is large, which will affect the final identity determination result, and then affect the positioning accuracy of the target, and cannot meet the actual engineering needs. Summary of the invention

[0006] In order to avoid the shortcomings of the prior art, the present application provides a distributed multi-infrared sensor collaborative guidance search and target identity determination method to solve the problems of low efficiency and poor accuracy caused by collaborative guidance strategies and identity determination problems when the distributed multi-infrared sensor networking detection system in the prior art performs target detection and positioning tracking in a complex environment.

[0007] According to an embodiment of the present disclosure, a distributed multi-infrared sensor collaborative guided search and target identity determination method is provided, the method comprising:

[0008] Step S1, determining the reference sensor and non-reference sensor in the infrared sensor, and taking the time when the reference sensor observes the target as the zero time, and taking the point where the height of the reference sensor is 0 at the zero time as the origin of the coordinate system, to establish a network coordinate system of distributed multi-infrared sensors;

[0009] Step S2, calculating the theoretical maximum detection distance of the infrared sensor according to the system characteristic parameters of each infrared sensor, and establishing the theoretical detection domain equation of each infrared sensor in the network coordinate system according to the theoretical maximum detection distance; wherein the theoretical maximum detection distance of the infrared sensor includes the maximum detection distance of the reference sensor and the maximum detection distance of the non-reference sensor;

[0010] Step S3, calculating the baseline direction vector equation of each non-reference sensor pointing to the reference sensor according to the coordinate positions of the reference sensor and the non-reference sensor in the network coordinate system at a preset time, and calculating the direction vector equation of the first direction finding line pointing from the optical center of the reference sensor to the target according to the pixel coordinate position of the target observed by the narrow field of view of the reference sensor;

[0011] Step S4, determining the search planes of the non-reference sensors according to the baseline direction vector equation, the first direction finding line direction vector equation, and the maximum detection distance of the reference sensor, and determining the center search point, the farthest search point, and the nearest search point on the guide search sector of the non-reference sensor in the search plane according to the detection characteristics of the infrared sensor, thereby determining the guide search sector of the non-reference sensor;

[0012] Step S5, calculating the farthest detection point of each non-reference sensor in the current orientation according to the actual orientation of each non-reference sensor, and calculating the Euclidean distances between the farthest detection point of each non-reference sensor and the central search point, the farthest search point and the nearest search point on the guide search sector respectively;

[0013] Step S6, according to the Euclidean distances between the farthest detection point of each non-reference sensor and the central search point, the farthest search point and the nearest search point on the guided search sector, a guided search strategy is selected to guide the non-reference sensor to point to the nearest search point, and the non-reference sensor is guided to search for the target according to the selected guided search strategy with the pointed search point as the starting point; wherein the guided search strategy includes the nearest search strategy, the farthest search strategy and the central search strategy;

[0014] Step S7, repeating steps S1 to S6, calculating and updating the guided search sectors of each non-reference sensor at each moment in real time, and adjusting the orientation of each non-reference sensor in combination with the updated search sectors, and determining whether a non-reference sensor observes the target during the search process on the guided search plane;

[0015] Step S8, if a non-reference sensor observes the target, the non-reference sensor is determined as an indicator sensor, and the identity of the observed target is determined by combining the two-dimensional observation information of the reference sensor and the two-dimensional observation information of the indicator sensor to determine whether the targets observed by the reference sensor and the indicator sensor are the same target in space;

[0016] Step S9, combining the target pixel coordinate position of the reference sensor and the indicator sensor to complete the target identity determination, calculating the position of the target in the network coordinate system, combining the remaining non-reference sensor positions and actual directions that have not yet observed the target, calculating the final guidance direction of the remaining non-reference sensors, completing rapid guidance for all remaining non-reference sensors, and completing coordinated detection and capture of the target.

[0017] Further, step S1 includes:

[0018] The infrared sensor that first observes the target in a narrow field of view among all infrared sensor nodes in the distributed multi-infrared sensor detection system is used as the reference sensor, and the collaborative guidance strategy of non-reference sensors is designed based on the two-dimensional detection information of the target in the reference sensor.

[0019] The time when the reference sensor observes the target is taken as the zero time, and the point where the reference sensor is located at the zero time is 0 as the origin of the coordinate system, and the network coordinate system of the distributed multi-infrared sensor is established; wherein the network coordinate system obeys the right-hand rule;

[0020] The longitude and latitude coordinates of each infrared sensor measured by the inertial navigation system are converted into a network coordinate system through coordinate transformation.

[0021] Further, step S2 includes:

[0022] Based on the system characteristic parameters of each infrared sensor, the theoretical maximum detection distance of each infrared sensor is obtained using the detection distance calculation formula of the infrared sensor; wherein the theoretical maximum detection distance of the infrared sensor is the detection distance result calculated when the number of pixels occupied by the point target in the imaging plane of the infrared sensor is 1;

[0023] Combining the theoretical maximum detection distance of the infrared sensor with the spatial position coordinates of each infrared sensor in the network coordinate system, the theoretical detection domain equation of each infrared sensor is obtained; wherein the theoretical detection domain equation of the infrared sensor includes the theoretical detection domain equation of the reference sensor and the theoretical detection domain equation of the non-reference sensor.

[0024] Further, step S3 includes:

[0025] Combining the positions of each infrared sensor in the network coordinate system, the baseline direction vector equation of the reference sensor pointing to any non-reference sensor is obtained;

[0026] Combined with the pixel coordinates of the target observed in the reference sensor, a direction vector equation of the second direction finding line in the reference sensor camera coordinate system is obtained;

[0027] The second direction finding line direction vector equation is converted to the networking coordinate system through coordinate transformation to obtain the first direction finding line direction vector equation in the networking coordinate system with the optical center of the reference sensor pointing to the target; wherein the intersection of the direction finding line direction vector and the baseline direction vector is the location point of the reference sensor.

[0028] Further, step S4 includes:

[0029] Determine the search plane of the non-reference sensor by the direction vector of the first direction-finding line from the optical center of the reference sensor to the target, the direction vector from the non-reference sensor to the reference sensor, and the maximum detection distance of the reference sensor;

[0030] In the non-reference sensor search plane, the farthest search point and the closest search point in the search plane are obtained according to the detection characteristics of the infrared sensor, and the central search point is obtained based on the maximum detection distance of the reference sensor, so as to determine the guide search sector of the non-reference sensor;

[0031] Among them, the two boundaries of the guided search fan are two rays pointing from the non-reference sensor to the farthest search point and the nearest search point. The farthest search point and the nearest search point both fall on the direction-finding line of the reference sensor pointing to the target. The farthest search point and the nearest search point are obtained by combining the detection characteristics of the infrared sensor and the farthest detection point of the reference sensor in the current direction. The central search point is the midpoint of the line segment between the farthest search point and the nearest search point.

[0032] Further, step S5 and step S6 include:

[0033] The actual orientation of each non-reference sensor at the current moment is obtained through the actual narrow field of view center pixel coordinates of the non-reference sensor, and the farthest detection point of each non-reference sensor at the current moment is obtained in combination with the maximum detection distance of the non-reference sensor;

[0034] Calculate the Euclidean distance between the farthest detection point of the non-reference sensor and each search point in the search plane, compare the sizes of each Euclidean distance, and determine the collaborative guidance search strategy of the non-reference sensor according to the size relationship of the Euclidean distance; wherein the guidance search strategy of the non-reference sensor includes the nearest search strategy, the farthest search strategy and the center search strategy;

[0035] The farthest search strategy is: guide the non-reference sensor to point to the farthest search point on the guided search sector; then take the farthest search point as the starting point and search along the guided search sector to the nearest search point;

[0036] The nearest search strategy is: guide the non-reference sensor to point to the nearest search point on the guided search sector; then take the nearest search point as the starting point and search along the guided search sector to the farthest search point;

[0037] The center search strategy is: guide the non-reference sensor to point to the center search point on the guide search sector; then take the center search point as the starting point and search along the guide search sector to the farthest search point or the nearest search point.

[0038] Further, step S7 and step S8 include:

[0039] In combination with the movement of the target, the movement of each infrared sensor itself and the scanning movement of each infrared sensor, the guided search sector of each non-reference sensor is updated in real time;

[0040] guiding each reference sensor to search for a target along a search sector according to a determined guiding search strategy;

[0041] When one of the non-reference sensors observes the target, the non-reference sensor that first observes the target is used as the indicator sensor. Starting from the moment when the indicator sensor observes the target, the pixel coordinates of the target in the reference sensor and the indicator sensor at multiple consecutive moments are recorded, and at each moment, the equation of the direction-finding line pointing from the optical center of each sensor to the target is calculated, and the foot distance of the common perpendicular line of the two direction-finding lines is calculated in the network coordinate system. The average of the foot distance of the common perpendicular line of the direction-finding lines at multiple consecutive moments is calculated based on the foot distance of the common perpendicular line of the two direction-finding lines, and the identity of the target observed by the reference sensor and the indicator sensor is determined based on the average result.

[0042] By setting a threshold for the distance to the foot of the common perpendicular line of the direction finding line, and comparing the calculated mean value of the distance to the foot of the common perpendicular line of the direction finding line with the threshold value for the distance to the foot of the common perpendicular line of the direction finding line; when the mean value is less than the threshold value, it is determined that the target captured by the reference sensor and the indicator sensor are the same target, otherwise it is determined that the target captured by the reference sensor and the indicator sensor are not the same target.

[0043] Further, step S9 includes:

[0044] According to the target identity determination results of the reference sensor and the indicator sensor, the collaborative guidance strategy of the remaining non-reference sensors is determined, the target pixel coordinate position of the target identity determination is combined with the reference sensor and the indicator sensor, the position of the target in the network coordinate system is calculated, and the position and actual orientation of the remaining non-reference sensors that have not yet observed the target are combined to calculate the final guidance orientation of the remaining non-reference sensors, and all the remaining non-reference sensors are quickly guided to complete the collaborative detection and capture of the target; in the guidance process of the remaining non-reference sensors, the target positioning point is updated in real time according to the movement of the target and the airborne dynamic platform to achieve the guidance of all the remaining non-reference sensors.

[0045] Furthermore, if the targets observed by the reference sensor and the indicator sensor are determined not to be the same target in space, the non-reference sensor marked as the indicator sensor continues to search along the guide search sector at the current moment according to the previous guide search strategy until a non-reference sensor observes the target, and then a new indicator sensor is re-determined and the identity determination of the targets observed by the reference sensor and the new indicator sensor is completed, until the targets observed by the reference sensor and the indicator sensor are determined to be the same target in space;

[0046] If the target observed by the reference sensor and the indicator sensor is determined to be the same target in space, the midpoint of the common perpendicular lines of the two first direction-finding lines pointing from the optical center of the reference sensor and the optical center of the indicator sensor to the respective observed targets at that moment is used as the positioning point of the target in space in the network coordinate system, and all remaining non-reference sensors except the indicator sensor are guided to point to the positioning point;

[0047] During the guidance of the remaining non-reference sensors, the target's positioning point needs to be updated in real time according to the target's and its own motion, so as to achieve the guidance of all the remaining non-reference sensors;

[0048] Among them, if a non-reference sensor other than the indicator sensor observes a target, the target information observed by the non-reference sensor is used to determine the identity with the target observed by the reference sensor, until the target observed by any non-reference sensor is determined to be the same target as the target observed by the reference sensor, and the remaining non-reference sensors complete the guidance according to the spatial positioning points calculated according to the identity determination result.

[0049] Furthermore, the method further comprises:

[0050] Multiple airborne mobile platforms at distributed locations are equipped with infrared sensors, and the infrared sensors cover their respective wide field of view detection ranges with a panoramic scanning strategy at a fixed scanning rate; among them,

[0051] The narrow field of view is the detection range of the sensor at a certain moment;

[0052] The wide field of view is a larger detection range that the sensor completes scanning coverage through a narrow field of view with a specified scanning strategy within a fixed scanning time period; the panoramic scanning strategy is: each infrared sensor completes panoramic scanning in both horizontal and vertical viewing directions at a preset scanning rate within a fixed period to cover the entire wide field of view detection range; after completing a panoramic scan, the infrared sensor restarts the next cycle of scanning;

[0053] The scanning rates of various infrared sensors are different, and data sharing is achieved between various infrared sensors through data links.

[0054] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0055] In the embodiments of the present disclosure, through the above-mentioned distributed multi-infrared sensor collaborative guidance search and target identity determination method, for the distributed multi-infrared sensor detection scene, the designed collaborative guidance search strategy can enable multiple infrared sensors at different nodes to work efficiently and collaboratively on the basis of information sharing, thereby expanding the observation area, reducing the search blind area, and improving the global perception capability of the detection system; the proposed collaborative guidance search strategy can dynamically adjust the collaborative guidance search sector of the non-reference sensor according to the data observed by the reference sensor in real time, so that the system can flexibly respond to environmental changes and target movement, and can significantly improve the collaborative detection efficiency and search capability of infrared sensors in various complex environments; the designed collaborative guidance search strategy has a wide range of application value, completes the identity determination of the target within a narrow field of view, reduces the influence of observation errors on the target identity determination results, and can significantly improve the actual application value and efficiency of the infrared sensor system in a variety of complex environments, and provides effective support for the identity determination, positioning and tracking of multiple targets under distributed infrared sensor network detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The figures herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the figures described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other figures can be obtained based on these figures without creative work.

[0057] Figure 1 A diagram showing the steps of a distributed multi-infrared sensor collaborative guided search and target identity determination method in an exemplary embodiment of the present disclosure;

[0058] Figure 2 A specific flow chart showing a method for distributed multi-infrared sensor collaborative guided search and target identity determination in an exemplary embodiment of the present disclosure;

[0059] Figure 3 A schematic diagram showing a distributed multi-infrared sensor collaborative networking detection scene in an exemplary embodiment of the present disclosure;

[0060] Figure 4 A schematic diagram showing a network coordinate system in an exemplary embodiment of the present disclosure;

[0061] Figure 5 A schematic diagram showing a theoretical spherical detection area of ​​a distributed multi-infrared sensor in an exemplary embodiment of the present disclosure is shown;

[0062] Figure 6 A schematic diagram showing a method of determining a non-reference sensor guided search sector based on reference sensor observation information in an exemplary embodiment of the present disclosure;

[0063] Figure 7 Schematic diagrams showing three cooperative guidance search strategies of non-reference sensors in exemplary embodiments of the present disclosure;

[0064] Figure 8 A schematic diagram showing a method for determining the identity of a target observed by a reference sensor and an indicator sensor in an exemplary embodiment of the present disclosure is shown;

[0065] Fig. 9 A schematic diagram showing how to complete target positioning and quickly guide remaining non-reference sensors based on identity determination results in an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0066] Example embodiments will now be described more fully with reference to the drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0067] In addition, the figures are only schematic illustrations of the embodiments of the present disclosure and are not necessarily drawn to scale. The same figure numbers in the figures represent the same or similar parts, and their repeated descriptions will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically independent entities.

[0068] This example embodiment provides a distributed multi-infrared sensor collaborative guided search and target identity determination method. Figure 1 As shown in , the distributed multi-infrared sensor collaborative guided search and target identity determination method may include:

[0069] Step S1, determining the reference sensor and non-reference sensor in the infrared sensor, and taking the time when the reference sensor observes the target as the zero time, and taking the point where the height of the reference sensor is 0 at the zero time as the origin of the coordinate system, to establish a network coordinate system of distributed multi-infrared sensors;

[0070] Step S2, calculating the theoretical maximum detection distance of the infrared sensor according to the system characteristic parameters of each infrared sensor, and establishing the theoretical detection domain equation of each infrared sensor in the network coordinate system according to the theoretical maximum detection distance; wherein the theoretical maximum detection distance of the infrared sensor includes the maximum detection distance of the reference sensor and the maximum detection distance of the non-reference sensor;

[0071] Step S3, calculating the baseline direction vector equation of each non-reference sensor pointing to the reference sensor according to the coordinate positions of the reference sensor and the non-reference sensor in the network coordinate system at a preset time, and calculating the direction vector equation of the first direction finding line pointing from the optical center of the reference sensor to the target according to the pixel coordinate position of the target observed by the narrow field of view of the reference sensor;

[0072] Step S4, determining the search planes of the non-reference sensors according to the baseline direction vector equation, the first direction finding line direction vector equation, and the maximum detection distance of the reference sensor, and determining the center search point, the farthest search point, and the nearest search point on the guide search sector of the non-reference sensor in the search plane according to the detection characteristics of the infrared sensor, thereby determining the guide search sector of the non-reference sensor;

[0073] Step S5, calculating the farthest detection point of each non-reference sensor in the current orientation according to the actual orientation of each non-reference sensor, and calculating the Euclidean distances between the farthest detection point of each non-reference sensor and the central search point, the farthest search point and the nearest search point on the guide search sector respectively;

[0074] Step S6, according to the Euclidean distances between the farthest detection point of each non-reference sensor and the central search point, the farthest search point and the nearest search point on the guided search sector, a guided search strategy is selected to guide the non-reference sensor to point to the nearest search point, and the non-reference sensor is guided to search for the target according to the selected guided search strategy with the pointed search point as the starting point; wherein the guided search strategy includes the nearest search strategy, the farthest search strategy and the central search strategy;

[0075] Step S7, repeating steps S1 to S6, calculating and updating the guided search sectors of each non-reference sensor at each moment in real time, and adjusting the orientation of each non-reference sensor in combination with the updated search sectors, and determining whether a non-reference sensor observes the target during the search process on the guided search plane;

[0076] Step S8, if a non-reference sensor observes the target, the non-reference sensor is determined as an indicator sensor, and the identity of the observed target is determined by combining the two-dimensional observation information of the reference sensor and the two-dimensional observation information of the indicator sensor to determine whether the targets observed by the reference sensor and the indicator sensor are the same target in space;

[0077] Step S9, combining the target pixel coordinate position of the reference sensor and the indicator sensor to complete the target identity determination, calculating the position of the target in the network coordinate system, combining the remaining non-reference sensor positions and actual directions that have not yet observed the target, calculating the final guidance direction of the remaining non-reference sensors, completing rapid guidance for all remaining non-reference sensors, and completing coordinated detection and capture of the target.

[0078] Through the above-mentioned distributed multi-infrared sensor collaborative guidance search and target identity determination method, the collaborative guidance search strategy designed for distributed multi-infrared sensor detection scenarios can enable multiple infrared sensors at different nodes to work efficiently and collaboratively on the basis of information sharing, expand the observation area, reduce the search blind area, and improve the global perception capability of the detection system; the proposed collaborative guidance search strategy can dynamically adjust the collaborative guidance search sector of the non-reference sensor according to the data observed by the reference sensor in real time, so that the system can flexibly respond to environmental changes and target movement, and can significantly improve the collaborative detection efficiency and search capability of infrared sensors in various complex environments; the designed collaborative guidance search strategy has a wide range of application value, completes the identity determination of the target in a narrow field of view, reduces the influence of observation errors on the target identity determination results, can significantly improve the actual application value and efficiency of the infrared sensor system in a variety of complex environments, and provides effective support for the identity determination, positioning and tracking of multiple targets under distributed infrared sensor network detection.

[0079] Next, we will refer to Figures 1 to 9 The various steps of the above-mentioned distributed multi-infrared sensor collaborative guided search and target identity determination method in this example implementation are described in more detail.

[0080] In a specific embodiment, three infrared sensors are used as an example to describe the complete process steps of applying this application to a typical distributed multi-infrared sensor collaborative detection scenario. Figure 3 In the typical application scenario shown, three airborne platforms (i.e., the first airborne platform, the second airborne platform, and the third airborne platform) are in distributed positions, respectively equipped with airborne infrared sensors (i.e., the first sensor, the second sensor, and the third sensor), and cover their own wide field of view detection areas according to a fixed scanning cycle. Multiple targets are observed in the wide field of view of the multi-sensor detection, and one of the targets has been determined to be the target to be captured. In the figure, the first sensor, the second sensor, and the third sensor are all in a stationary or moving state with the random airborne platform. The detection field of view of the first sensor can be divided into the narrow field of view of the first sensor and the wide field of view of the first sensor, the detection field of view of the second sensor can be divided into the narrow field of view of the second sensor and the wide field of view of the second sensor, and the detection field of view of the third sensor can be divided into the narrow field of view of the third sensor and the wide field of view of the third sensor, wherein the wide field of view is the entire area that each airborne infrared sensor can detect and cover under the field of view restriction conditions such as installation, and each sensor covers the wide field of view detection range with a fixed scanning cycle according to the narrow field of view size. In addition, this application does not consider the installation position of the airborne infrared sensor relative to the airborne platform, that is, it is assumed that the coordinate position of the center of mass of the airborne platform itself coincides with the spatial coordinate position of the center of mass of the sensor or the optical center of the sensor. Figure 2 The specific process steps shown are combined with Figure 3 The distributed multi-sensor collaborative network detection scene shown in the figure, in addition, the number of sensors in this embodiment is not limited to Figure 3 The three sensors shown in the scenario can also be expanded to multiple sensors.

[0081] To complete this embodiment, the following steps are specifically included:

[0082] In step S1, first, multiple airborne moving platforms at distributed locations are respectively equipped with infrared sensors to cover their respective wide-field detection ranges using a panoramic scanning strategy at a fixed scanning rate.

[0083] The specific panoramic scanning strategy of each infrared sensor is: each sensor (i.e. infrared sensor) completes panoramic scanning in both horizontal and vertical viewing angles at a specified scanning rate within a fixed period to cover the entire wide field of view detection range. After completing a panoramic scan, the sensor will restart the next scanning cycle. The scanning rates of multiple sensors may be different, and data sharing is completed between multiple sensors through data links.

[0084] Determine which sensor's narrow field of view first observes the target, take the sensor that first observes the target as the reference sensor, take the time when the reference sensor observes the target as the zero time, take the point where the reference sensor is located at the zero time as the origin of the coordinate system, and establish a distributed multi-sensor network coordinate system. The network coordinate system's X-axis points to the east, the Y-axis points to the north, and the Z-axis is perpendicular to the ground and points upward. The network coordinate system obeys the right-hand rule.

[0085] Since each airborne platform has different positions in space, different orientations of sensors, and different scanning rates, one of the multiple sensors will inevitably find the target first with its narrow field of view. The sensor that finds the target first is used as the reference sensor. The purpose is to design the collaborative guidance strategy of non-reference sensors in the distributed multi-sensor detection system based on the two-dimensional detection information of the target in the reference sensor as a prerequisite.

[0086] The position of an airborne platform is usually measured by an inertial navigation system. The position of the airborne platform measured by the inertial navigation system is usually expressed in longitude and latitude coordinates in the geodetic coordinate system. The coordinates of the airborne platform in the geocentric earth-fixed coordinate system can be solved by coordinate transformation. The coordinate transformation formula is as follows:

[0087]

[0088] In the formula, superscript Indicates a moment in time, the subscript represents the Earth-centered Earth-fixed coordinate system, For the The longitude, latitude, and altitude coordinates of the center of mass of the airborne platform at this moment. are the coefficients of the ellipse expression of the meridian ellipse plane at the location of the airborne platform, representing the major axis radius and minor axis radius of the ellipse respectively. For the The coordinates of the center of mass of the airborne platform in the earth-fixed system at the center of the earth at the moment, To express the coefficients through an ellipse The first parameter to be solved is, is the second parameter solved by the above parameter combination.

[0089] Since distributed multi-sensors are mostly used for networking to detect targets in a specified area, the distance between multiple sensors is usually not too far. Therefore, the position information of each sensor in the distributed multi-sensor detection system can be combined to establish a local world coordinate system to unify the coordinate system of the entire distributed multi-sensor detection system. This coordinate system can be called a networking coordinate system. The purpose of establishing a networking coordinate system is to enable multiple sensors to complete observation, positioning and tracking tasks in a unified coordinate system to reduce observation errors and positioning errors caused by spatial registration problems.

[0090] Based on the reference sensor The time when the target is observed is the initial zero time, and the point where the reference sensor is located at a height of 0 at this time is taken as the origin of the network coordinate system. The purpose is to make the origin of the network coordinate system close to each sensor to reduce the temporary coordinate transformation error of the coordinate system. Suppose the Earth-centered Earth-fixed coordinate when the reference sensor observes the target is , then Non-reference sensors In the The position of the network coordinate system at the moment It can be obtained by the following formula:

[0091]

[0092] In the formula For the The non-reference sensor is The latitude and longitude coordinates of the time, For the The non-reference sensor is The network coordinate system obeys the right-hand rule. The axis points east, The axis points north, The axis is perpendicular to the ground and points upward, such as Figure 4The figure shows a schematic diagram of establishing a network coordinate system for a distributed multi-infrared sensor detection system. In the figure, three airborne platforms equipped with infrared sensors are in distributed positions. The first sensor carried by the first airborne platform first discovers the target. The moment when the first sensor discovers the target is taken as time 0, and the point where the height of the first sensor at this moment is 0 is taken as the origin of the network coordinate system. In order to unify the coordinate system of the entire distributed multi-sensor network detection system, all subsequent calculations in this embodiment are completed in the network coordinate system.

[0093] In step S2, the theoretical maximum detection distance of the sensor is calculated based on the system characteristic parameters of each airborne infrared sensor, such as transmittance, aperture, bandwidth, signal-to-noise ratio, numerical aperture, etc., and the theoretical detection domain equation of each infrared sensor is established in the network coordinate system based on the maximum detection distance of each sensor to describe the three-dimensional spatial detection capability of each airborne infrared sensor.

[0094] Infrared sensors are usually used to detect long-distance targets. This embodiment also detects long-distance targets. Due to the long distance, the projection of the target on the imaging plane of the sensor is a point target that occupies only a few pixels. It can be obtained by the following formula:

[0095]

[0096] In the formula represents the radiation intensity of the target, represents the sensor's entrance pupil diameter, represents the optical transmittance of the sensor, represents the atmospheric transmittance, It represents the detector specific detection degree, represents the focal length of the sensor, Represents the area of ​​a single pixel of the sensor, It represents the instantaneous field of view angle corresponding to a single pixel of the detector, represents the numerical aperture of the sensor, represents the equivalent noise bandwidth, represents the signal-to-noise ratio, Indicates the number of pixels occupied by the point source target in the sensor imaging plane. Theoretically, the critical distance where the target is 1 pixel on the infrared imaging plane is the farthest working distance of the detector. Set to 1, the maximum detection distance of the sensor can be obtained ,Right now:

[0097]

[0098] Combining the maximum detection distance of the sensor with the spatial position coordinates of each sensor in the network coordinate system, the theoretical detection domain of any infrared sensor at any time can be obtained. Assuming that the characteristic parameters of the airborne infrared sensors carried by the three airborne platforms in the embodiment are the same, the theoretical detection domain equations of the reference sensor and the non-reference sensor can be expressed as follows:

[0099]

[0100] In the formula The reference sensor is The network coordinate system coordinates at the moment, For the The non-reference sensor is The network coordinate system coordinates at the moment, is the coordinate variable, The above formula means that if the installation and factory settings of the infrared sensor are not considered to limit the field of view, the theoretical detection range of the infrared sensor is a spherical detection range that is smaller than its maximum detection distance. The theoretical spherical detection range of each infrared sensor in this embodiment without considering the installation restrictions is shown in Figure 5 .

[0101] In step S3, based on the coordinate positions of the reference sensor and the non-reference sensor in the network coordinate system at a certain moment, the baseline direction vector equation of multiple non-reference sensors pointing to the reference sensor is calculated, and based on the pixel coordinate position of the target observed by the narrow field of view of the reference sensor, the direction vector equation of the first direction finding line pointing from the optical center of the reference sensor to the target in the network coordinate system is calculated.

[0102] Multiple airborne platforms are at different positions in the air. At this moment, set the reference sensor The coordinates in the network coordinate system are , No. Non-reference sensors The coordinates in the network coordinate system are , then The baseline direction vector of the non-reference sensors pointing to the reference sensor The equation can be expressed as:

[0103]

[0104] In the two-dimensional imaging plane of the reference sensor, At this moment, the target The pixel coordinates in the imaging plane are , then the direction vector from the optical center of the reference sensor to the target can be obtained by the following steps:

[0105] First, in the reference sensor camera coordinate system, the direction vector from the reference sensor optical center to the target pixel coordinate can be expressed as:

[0106]

[0107] in,

[0108]

[0109] In the formula represents the camera pixel size of the base sensor, represents the pixel coordinates of the center of the two-dimensional imaging plane of the reference sensor, Indicates the camera focal length of the base sensor.

[0110] Secondly, the above direction vector is converted to the network coordinate system for expression, and the solution formula is as follows:

[0111]

[0112] In the formula It represents the direction vector of the first direction finding line from the optical center of the reference sensor to the target in the sensor imaging plane in the network coordinate system. Represents the transformation matrix from the network coordinate system to the reference sensor camera coordinate system. The matrix is ​​expressed as follows:

[0113]

[0114] in,

[0115]

[0116] In the formula Represent the pitch, yaw, and roll angles of the reference sensor camera respectively. They represent the errors of the sensor in pitch, yaw and roll directions respectively. The errors can usually be obtained by the angle measurement accuracy of the sensor. For a non-reference sensor, the transformation matrix from its network coordinate system to its own camera coordinate system is The solution to is similar to the above formula.

[0117] Through the above steps, we can obtain The direction vector of the first direction finding line of the reference sensor optical center pointing to the target in its own imaging plane and The non-reference sensor points to the reference sensor baseline direction vector , the intersection of the two direction vectors in the network coordinate system is the location of the reference sensor at the current moment.

[0118] In step S4, the search planes of each non-reference sensor are determined based on the baseline direction vector equation, the first direction finding line direction vector equation, and the maximum detection distance of the reference sensor. In the search plane, the center search point, the farthest search point, and the nearest search point on the non-reference sensor's guided search sector are determined based on the sensor detection characteristics to determine the non-reference sensor's guided search sector.

[0119] Through the The direction vector of the first direction finding line of the reference sensor optical center pointing to the target in its own imaging plane and any The non-reference sensor points to the reference sensor baseline direction vector and the position of the reference sensor at the current moment , it is possible to determine a unique plane, which is the non-reference sensor At the current moment of the search plane, the equation of the search plane can be expressed in the form of the following parametric equation:

[0120]

[0121] In the formula is a coordinate variable, which represents the coordinates of any point on the search plane. is any real number parameter.

[0122] In this search plane, the non-reference sensor guided search sector can be determined based on the maximum detection distance of the reference sensor and the detection characteristics of the infrared sensor. The solution method for the guided search sector is as follows: Figure 6 The specific description is as follows:

[0123] First, the farthest detection point of the reference sensor is obtained by the maximum detection distance of the reference sensor. According to the coordinates of the farthest detection point and the current position of the reference sensor, the direction finding line segment pointing to the target can be obtained. .like Figure 7 As shown in a in FIG. 1 , it is a schematic diagram of the farthest search strategy.

[0124] Secondly, according to the detection characteristics of infrared sensors, if the sensor imaging plane wants to determine the existence of a target, it is necessary to ensure that the target imaging reaches a certain resolution level. Therefore, it is difficult to observe the target when the target is at its maximum detection distance. At the same time, when the target is close to the sensor, the imaging is no longer a point target. The farthest search point of the non-reference sensor in the search plane at any time , Recent Search Points and the center search point . The farthest search point Falling on the direction finding line segment The distance from the farthest detection point is one tenth of the length of the direction finding line segment. Falling on the direction finding line segment The distance from the reference sensor is one tenth of the length of the direction finding line segment. The center search point Direction finding line segment The midpoint of Figure 7 As shown in b and c, they are schematic diagrams of the center search strategy and the nearest search strategy, respectively.

[0125] Non-reference sensors are The boundary of the guidance search sector at the moment is the current position coordinate of the non-reference sensor Line segment pointing to the nearest search point And the current position coordinates of the non-reference sensor The line segment pointing to the farthest search point .

[0126] In step S5 and step S6, according to the actual orientations of the multiple non-reference sensors, the farthest detection point of each non-reference sensor in the current orientation is calculated, and the Euclidean distance between the farthest detection point of the non-reference sensor and the central search point, the farthest search point, and the nearest search point on the guided search sector is calculated. In combination with the calculated Euclidean distance, a suitable guided search strategy is selected to guide the non-reference sensor to point to the nearest search point first, and then the non-reference sensor is guided to search for the target based on the selected search strategy with the pointed search point as the starting point.

[0127] In the Moment Non-reference sensors The actual orientation can be expressed by the direction vector obtained by the pixel coordinates of the center point of its narrow field of view. The center point of the non-reference sensor narrow field of view imaging plane is , which is not a reference sensor The direction vector in the camera coordinate system and the network coordinate system can be expressed as:

[0128]

[0129] in Indicates Moment Non-reference sensors The narrow field of view direction vector in its own camera coordinate system, Indicates its focal length. Indicates the coordinate system from the network to the The transformation matrix of the non-reference sensor camera coordinate system, Indicates Moment Non-reference sensors The field of view direction vector in the network coordinate system.

[0130] At this moment, Non-reference sensors The farthest detection point can be detected by its maximum detection distance and the direction vector Assume that the farthest detection point is , it is known that the non-reference sensor obtained in step S5 The farthest search point on the search sector is , the nearest search point is and the center search point is , the Euclidean distances between the farthest detection point and the above three search points are:

[0131]

[0132] in Respectively Moment Non-reference sensors The Euclidean distances between the farthest detection point under the current narrow field of view and the direction-finding line pointed to the target by the reference sensor and the farthest search point, the nearest search point and the center search point are obtained by combining the sensor characteristics.

[0133] Compare the three distances above The size of the non-reference sensor is determined according to the size relationship. The three cooperative guidance strategies of the non-reference sensor are as follows: Figure 7 The specific description is as follows:

[0134] 1. When and , it is determined to use the farthest search strategy.

[0135] The farthest search strategy is: first guide the non-reference sensor along Rotate it to quickly point to the farthest search point on the guiding search sector, and then start from the farthest search point and search along the guiding search sector to the nearest search point.

[0136] 2. When and , it is determined to use the nearest search strategy.

[0137] The closest search strategy is: first guide the non-reference sensor along Rotate it to quickly point to the nearest search point on the guide search sector, and then start from the farthest search point and search along the guide search sector to the farthest search point.

[0138] 3. When and , it is determined to use the central search strategy.

[0139] The center search strategy is: first guide the non-reference sensors along Rotate it to quickly point to the center search point on the guide search sector, and then use the center search point as the starting point to search along the guide search sector to the farthest search point or the nearest search point.

[0140] In step S7 and step S8, the above six steps are repeated according to the movement of each infrared sensor itself and the position and actual orientation of each infrared sensor at any time, so as to calculate and update the guiding search sector of each non-reference sensor at each time in real time, and adjust the orientation of each non-reference sensor in combination with the updated search sector. During the search process on the guiding search plane, it is determined whether a non-reference sensor observes the target. If a non-reference sensor observes the target, the non-reference sensor is determined as the indicator sensor. The identity of the observed target is determined by combining the two-dimensional observation information of the reference sensor and the two-dimensional observation information of the indicator sensor to determine whether the targets observed by the two sensors are the same target in space.

[0141] In the distributed multi-sensor network detection system, multiple non-reference sensors combine their own positions and their own guided search sectors to search for targets along the search sectors according to their respective search strategies. In the process of non-reference sensors searching for targets along the guided search sectors, when the narrow field of view of one of the non-reference sensors captures the target, the non-reference sensor that first captures the target is used as the indicator sensor. The time for the indicator sensor to capture the target is , from the current Start at the moment and record the subsequent The pixel coordinate position of the target observed in the two-dimensional imaging plane of the reference sensor and the indicator sensor at each moment, and the direction finding line equation pointing from the optical center of each sensor to the target is calculated at each moment, and the continuous The distance between the common perpendiculars of the two direction-finding lines at a given moment is used to calculate the distance from Time to The method of calculating the distance of the foot of the common perpendicular line of the direction vector at multiple consecutive moments based on the target observed by the indicator sensor and the reference sensor and completing the identity determination of the observed target is as follows: Figure 8 As shown, combined Figure 8 The detailed description of this method is as follows:

[0142] 1. According to the pixel coordinates of the target observed by the reference sensor and the indicator sensor, the direction vector of the first direction finding line pointing from the optical center of each sensor to the target is obtained.

[0143] Set up The position of the optical center of the time reference sensor in the network coordinate system is , indicating that the position of the optical center of the sensor in the network coordinate system is , the target they observed and The pixel coordinates in the two-dimensional imaging plane are and Similar to the method for solving the direction vector of the first direction finding line in step S3, it is possible to solve the direction of the optical center of the non-reference sensor pointing to the target in the network coordinate system. The direction vector of the direction finding line With the pointing sensor pointing to the target The direction vector of the direction finding line .

[0144] 2. Calculate the direction vector and The distance between the common perpendicular lines .

[0145] Common vertical line satisfy and ,and With direction vector The intersection point is , With direction vector The intersection point is , and They are the feet of the common perpendicular lines on the direction vectors of the reference sensor and the indicator sensor, respectively. They can be expressed by the following formula:

[0146]

[0147] in, , is an unknown parameter and can be obtained by solving the following set of equations:

[0148]

[0149] Combined with the above formula, we can get the direction vector and The distance between the common perpendicular lines It is expressed by the following formula:

[0150]

[0151] 3. Calculate the Continuous after time At each moment, the reference sensor and the indicator sensor point to the direction vector of the direction finding line of the target, and calculate the perpendicular distance between the two perpendicular lines of the direction vectors of the direction finding lines at each moment, and record these perpendicular distances to calculate the direction from the first moment. Time to The mean distance between the common perpendicular lines of the direction vectors of the two targets at the moment To measure the central tendency of the distance between the common perpendicular lines of the direction vectors of the direction finding lines of the two targets over a period of time. The calculation formula is as follows:

[0152]

[0153] in Represents the number of consecutive statistical moments of the distance to the foot of the common perpendicular line. represents the time variable, Indicates any The distance from the foot of the common perpendicular at the moment.

[0154] 4. Set the mean threshold of the common vertical line foot distance , and compare and If the mean of the distance between the common perpendicular line and the foot of the common perpendicular line is less than the mean threshold, that is, , then it is determined that the target captured by the reference sensor and the indicator sensor is the same target, otherwise it is determined that the target captured by the reference sensor and the indicator sensor is not the same target.

[0155] In step S9, according to the result of the identity determination of the targets in the reference sensor and the indicator sensor, the collaborative guidance strategy of the remaining non-reference sensors is determined: if the targets observed by the reference sensor and the indicator sensor are determined not to be the same target in space, the non-reference sensor marked as the indicator sensor continues to search along its own guidance search sector according to the previous guidance strategy until another non-reference sensor observes the target, and then a new indicator sensor is re-determined and the identity determination of the targets observed by the two sensors is completed, until the targets observed by the reference sensor and the indicator sensor are determined to be the same target in space; if the targets observed by the reference sensor and the indicator sensor are determined to be the same target in space, the midpoint of the common perpendicular line of the direction vector at that moment is used as the positioning point of the target in space in the network coordinate system, and all the remaining non-reference sensors except the indicator sensor are guided to quickly point to the positioning point. During the guidance process of the remaining non-reference sensors, the positioning point of the target needs to be updated in real time according to the movement of the target and itself, so as to achieve rapid guidance of all the remaining non-reference sensors.

[0156] Located in At this moment, the identity of the target observed by the reference sensor and the indicator sensor is determined. Under this premise, the target in space is located through the targets observed by the reference sensor and the indicator sensor, and the specific method of guiding the remaining non-reference sensors is as follows: Fig. 9 As shown, combined Fig. 9 The detailed description of the method is as follows:

[0157] According to the calculation method in the above steps S5 and S6, the foot of the common perpendicular line on the direction vector of the direction finding line of the reference sensor and the indicator sensor pointing to the target at the current moment can be calculated. and , calculate the common perpendicular line based on these two perpendicular feet midpoint , and As the target's positioning point in the space under the network coordinate system, the target's positioning point in the space under the network coordinate system The solution formula is as follows:

[0158]

[0159] After obtaining the position of the target in the network coordinate system, the farthest detection point of each remaining sensor in the current orientation is calculated by combining the orientation and actual position of the remaining non-reference sensors at the current moment, and the remaining sensors are guided to rotate along the direction vector from the farthest detection point to the positioning point of the target in the network coordinate system, so as to achieve rapid guidance of all remaining non-reference sensors. During the guidance process, the positioning point of the target in space is calculated in real time, so that the remaining reference sensors can quickly and accurately capture the target.

[0160] Since all sensors work independently, in the above process, if a non-reference sensor other than the indicator sensor observes a target, steps S7 and S8 are completed based on the target information observed by the non-reference sensor to achieve identity determination with the target observed by the reference sensor, until the target observed by any non-reference sensor is determined to be the same target as the target observed by the reference sensor, then the remaining non-reference sensors complete rapid guidance according to the spatial positioning points calculated according to the identity determination results.

[0161] Through the above steps, the rapid collaborative guidance search and target identity determination of multiple sensors in the distributed multi-sensor network detection system is completed. The designed collaborative guidance method is used to dynamically formulate the optimal search sector and strategy of the non-reference sensor based on the two-dimensional observation information of the target by the reference sensor. Combined with the observation information of the target, the search sector is dynamically adjusted, and the non-reference sensors at different node positions are collaboratively guided to point to the target, thereby reducing the time of target search and improving the efficiency of overall detection. At the same time, the identity determination of the target observed by multiple infrared sensors is completed based on the two-dimensional observation information in the collaborative search stage, and then the capture of the target is realized, providing effective support for the tracking and positioning of subsequent targets in the distributed network detection scene, and improving the positioning accuracy of the distributed multi-infrared sensor network detection system. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0162] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0163] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A distributed multi-infrared sensor collaborative guided search and target identity determination method, characterized in that: The method includes: Step S1, determining the reference sensor and non-reference sensor in the infrared sensor, and taking the time when the reference sensor observes the target as the zero time, and taking the point where the height of the reference sensor is 0 at the zero time as the origin of the coordinate system, to establish a network coordinate system of distributed multi-infrared sensors; Step S2, calculating the theoretical maximum detection distance of the infrared sensor according to the system characteristic parameters of each infrared sensor, and establishing the theoretical detection domain equation of each infrared sensor in the network coordinate system according to the theoretical maximum detection distance; wherein the theoretical maximum detection distance of the infrared sensor includes the maximum detection distance of the reference sensor and the maximum detection distance of the non-reference sensor; Step S3, calculating the baseline direction vector equation of each non-reference sensor pointing to the reference sensor according to the coordinate positions of the reference sensor and the non-reference sensor in the network coordinate system at a preset time, and calculating the direction vector equation of the first direction finding line pointing from the optical center of the reference sensor to the target according to the pixel coordinate position of the target observed by the narrow field of view of the reference sensor; Step S4, determining the search planes of the non-reference sensors according to the baseline direction vector equation, the first direction finding line direction vector equation, and the maximum detection distance of the reference sensor, and determining the center search point, the farthest search point, and the nearest search point on the guide search sector of the non-reference sensor in the search plane according to the detection characteristics of the infrared sensor, thereby determining the guide search sector of the non-reference sensor; Step S5, calculating the farthest detection point of each non-reference sensor in the current orientation according to the actual orientation of each non-reference sensor, and calculating the Euclidean distances between the farthest detection point of each non-reference sensor and the central search point, the farthest search point and the nearest search point on the guide search sector respectively; Step S6, according to the Euclidean distances between the farthest detection point of each non-reference sensor and the central search point, the farthest search point and the nearest search point on the guided search sector, a guided search strategy is selected to guide the non-reference sensor to point to the nearest search point, and the non-reference sensor is guided to search for the target according to the selected guided search strategy with the pointed search point as the starting point; wherein the guided search strategy includes the nearest search strategy, the farthest search strategy and the central search strategy; Step S7, repeating steps S1 to S6, calculating and updating the guided search sectors of each non-reference sensor at each moment in real time, and adjusting the orientation of each non-reference sensor in combination with the updated search sectors, and determining whether a non-reference sensor observes the target during the search process on the guided search plane; Step S8, if a non-reference sensor observes the target, the non-reference sensor is determined as an indicator sensor, and the identity of the observed target is determined by combining the two-dimensional observation information of the reference sensor and the two-dimensional observation information of the indicator sensor to determine whether the targets observed by the reference sensor and the indicator sensor are the same target in space; Step S9, combining the target pixel coordinate position of the reference sensor and the indicator sensor to complete the target identity determination, calculating the position of the target in the network coordinate system, combining the remaining non-reference sensor positions and actual directions that have not yet observed the target, calculating the final guidance direction of the remaining non-reference sensors, completing rapid guidance for all remaining non-reference sensors, and completing coordinated detection and capture of the target.

2. The distributed multi-infrared sensor collaborative guided search and target identity determination method according to claim 1, characterized in that: Step S1 includes: The infrared sensor that first observes the target in a narrow field of view among all infrared sensor nodes in the distributed multi-infrared sensor detection system is used as the reference sensor, and the collaborative guidance strategy of non-reference sensors is designed based on the two-dimensional detection information of the target in the reference sensor. The time when the reference sensor observes the target is taken as the zero time, and the point where the reference sensor is located at the zero time is 0 as the origin of the coordinate system, and the network coordinate system of the distributed multi-infrared sensor is established; wherein the network coordinate system obeys the right-hand rule; The longitude and latitude coordinates of each infrared sensor measured by the inertial navigation system are converted into a network coordinate system through coordinate transformation.

3. The distributed multi-infrared sensor collaborative guided search and target identity determination method according to claim 2 is characterized in that: Step S2 includes: Based on the system characteristic parameters of each infrared sensor, the theoretical maximum detection distance of each infrared sensor is obtained using the detection distance calculation formula of the infrared sensor; wherein the theoretical maximum detection distance of the infrared sensor is the detection distance result calculated when the number of pixels occupied by the point target in the imaging plane of the infrared sensor is 1; Combining the theoretical maximum detection distance of the infrared sensor with the spatial position coordinates of each infrared sensor in the network coordinate system, the theoretical detection domain equation of each infrared sensor is obtained; wherein the theoretical detection domain equation of the infrared sensor includes the theoretical detection domain equation of the reference sensor and the theoretical detection domain equation of the non-reference sensor.

4. The distributed multi-infrared sensor collaborative guided search and target identity determination method according to claim 3 is characterized in that: Step S3 includes: Combining the positions of each infrared sensor in the network coordinate system, the baseline direction vector equation of the reference sensor pointing to any non-reference sensor is obtained; Combined with the pixel coordinates of the target observed in the reference sensor, a direction vector equation of the second direction finding line in the reference sensor camera coordinate system is obtained; The second direction finding line direction vector equation is converted to the networking coordinate system through coordinate transformation to obtain the first direction finding line direction vector equation in the networking coordinate system with the optical center of the reference sensor pointing to the target; wherein the intersection of the direction finding line direction vector and the baseline direction vector is the location point of the reference sensor.

5. The distributed multi-infrared sensor collaborative guided search and target identity determination method according to claim 4 is characterized in that: Step S4 includes: The search plane of the non-reference sensor is determined by the direction vector of the first direction-finding line from the optical center of the reference sensor to the target, the direction vector from the non-reference sensor to the reference sensor, and the maximum detection distance of the reference sensor. In the non-reference sensor search plane, the farthest search point and the closest search point in the search plane are obtained according to the detection characteristics of the infrared sensor, and the central search point is obtained based on the maximum detection distance of the reference sensor, so as to determine the guide search sector of the non-reference sensor; Among them, the two boundaries of the guided search fan are two rays pointing from the non-reference sensor to the farthest search point and the nearest search point. The farthest search point and the nearest search point both fall on the direction-finding line of the reference sensor pointing to the target. The farthest search point and the nearest search point are obtained by combining the detection characteristics of the infrared sensor and the farthest detection point of the reference sensor in the current direction. The central search point is the midpoint of the line segment between the farthest search point and the nearest search point.

6. The distributed multi-infrared sensor collaborative guided search and target identity determination method according to claim 5, characterized in that: Step S5 and step S6 include: The actual orientation of each non-reference sensor at the current moment is obtained through the actual narrow field of view center pixel coordinates of the non-reference sensor, and the farthest detection point of each non-reference sensor at the current moment is obtained in combination with the maximum detection distance of the non-reference sensor; Calculate the Euclidean distance between the farthest detection point of the non-reference sensor and each search point in the search plane, compare the sizes of each Euclidean distance, and determine the collaborative guidance search strategy of the non-reference sensor according to the size relationship of the Euclidean distance; wherein the guidance search strategy of the non-reference sensor includes the nearest search strategy, the farthest search strategy and the center search strategy; The farthest search strategy is: guide the non-reference sensor to point to the farthest search point on the guided search sector; then take the farthest search point as the starting point and search along the guided search sector to the nearest search point; The nearest search strategy is: guide the non-reference sensor to point to the nearest search point on the guided search sector; then take the nearest search point as the starting point and search along the guided search sector to the farthest search point; The center search strategy is: guide the non-reference sensor to point to the center search point on the guide search sector; then take the center search point as the starting point and search along the guide search sector to the farthest search point or the nearest search point.

7. The distributed multi-infrared sensor collaborative guided search and target identity determination method according to claim 6, characterized in that: Step S7 and step S8 include: In combination with the movement of the target, the movement of each infrared sensor itself and the scanning movement of each infrared sensor, the guided search sector of each non-reference sensor is updated in real time; guiding each reference sensor to search for a target along a search sector according to a determined guiding search strategy; When one of the non-reference sensors observes the target, the non-reference sensor that first observes the target is used as the indicator sensor. Starting from the moment when the indicator sensor observes the target, the pixel coordinates of the target in the reference sensor and the indicator sensor at multiple consecutive moments are recorded, and at each moment, the equation of the direction-finding line pointing from the optical center of each sensor to the target is calculated, and the foot distance of the common perpendicular line of the two direction-finding lines is calculated in the network coordinate system. The average of the foot distance of the common perpendicular line of the direction-finding lines at multiple consecutive moments is calculated based on the foot distance of the common perpendicular line of the two direction-finding lines, and the identity of the target observed by the reference sensor and the indicator sensor is determined based on the average result. By setting a threshold for the distance to the foot of the common perpendicular line of the direction finding line, and comparing the calculated mean value of the distance to the foot of the common perpendicular line of the direction finding line with the threshold value for the distance to the foot of the common perpendicular line of the direction finding line; when the mean value is less than the threshold value, it is determined that the target captured by the reference sensor and the indicator sensor are the same target, otherwise it is determined that the target captured by the reference sensor and the indicator sensor are not the same target.

8. The distributed multi-infrared sensor collaborative guided search and target identity determination method according to claim 7, characterized in that: Step S9 includes: According to the target identity determination results of the reference sensor and the indicator sensor, the collaborative guidance strategy of the remaining non-reference sensors is determined, the target pixel coordinate position of the target identity determination is combined with the reference sensor and the indicator sensor, the position of the target in the network coordinate system is calculated, and the position and actual orientation of the remaining non-reference sensors that have not yet observed the target are combined to calculate the final guidance orientation of the remaining non-reference sensors, and all the remaining non-reference sensors are quickly guided to complete the collaborative detection and capture of the target; in the guidance process of the remaining non-reference sensors, the target positioning point is updated in real time according to the movement of the target and the airborne dynamic platform to achieve the guidance of all the remaining non-reference sensors.

9. The distributed multi-infrared sensor collaborative guided search and target identity determination method according to claim 8, characterized in that: If the target observed by the reference sensor and the indicator sensor is determined not to be the same target in space, the non-reference sensor marked as the indicator sensor continues to search along the current guidance search sector according to the previous guidance search strategy until a non-reference sensor observes the target, and then a new indicator sensor is re-determined and the identity determination of the target observed by the reference sensor and the new indicator sensor is completed, until the target observed by the reference sensor and the indicator sensor is determined to be the same target in space; If the target observed by the reference sensor and the indicator sensor is determined to be the same target in space, the midpoint of the common perpendicular lines of the direction vectors of the two first direction-finding lines pointing from the optical center of the reference sensor and the optical center of the indicator sensor to the respective observed targets at the current moment is used as the positioning point of the target in space in the network coordinate system, and all remaining non-reference sensors except the indicator sensor are guided to point to the positioning point; During the guidance of the remaining non-reference sensors, the target's positioning point needs to be updated in real time according to the target's and its own motion, so as to achieve the guidance of all the remaining non-reference sensors; Among them, if a non-reference sensor other than the indicator sensor observes a target, the target information observed by the non-reference sensor is used to determine the identity with the target observed by the reference sensor, until the target observed by any non-reference sensor is determined to be the same target as the target observed by the reference sensor, and the remaining non-reference sensors complete the guidance according to the spatial positioning points calculated according to the identity determination result.

10. The distributed multi-infrared sensor collaborative guided search and target identity determination method according to claim 1, characterized in that: The method further includes: Multiple airborne mobile platforms at distributed locations are equipped with infrared sensors, and the infrared sensors cover their respective wide field of view detection ranges with a panoramic scanning strategy at a fixed scanning rate; among them, The narrow field of view is the detection range of the sensor at a certain moment; A wide field of view is a larger detection range that the sensor can cover by scanning with a narrow field of view using a specified scanning strategy within a fixed scanning period. The panoramic scanning strategy is: each infrared sensor completes panoramic scanning in both horizontal and vertical viewing angles at a preset scanning rate within a fixed period to cover the entire wide field of view detection range; after completing a panoramic scan, the infrared sensor restarts the next cycle of scanning; The scanning rates of various infrared sensors are different, and data sharing is achieved between various infrared sensors through data links.

Images