An auxiliary guidance and tracking method

Abstract

The present invention discloses an auxiliary guidance and tracking method, comprising the following steps: Step 1, an analyst observes the azimuth history diagram, selects the target to be tracked, and obtains the current target beam and the current target beam number; at least 2 trajectory points are selected and marked on the target trajectory; Step 2, the marked points are interpolated according to the output frequency of the target precise measurement azimuth, and an auxiliary tracking guidance line composed of a number of guidance points is formed; Step 3, n adjacent beams are selected on each side of the current target beam, interpolation is performed on the current target beam and the selected adjacent beams, and the current target precise measurement azimuth is calculated; Step 4, the difference between the current target precise measurement azimuth and the current guidance azimuth is calculated and compared with a preset angle threshold, and the current target tracking output azimuth and the next target beam are updated based on the target update strategy of the comparison result; Step 5, the current guidance azimuth is updated to the next guidance azimuth, the next target beam is used as the current target beam, and the process returns to Step 3.

Description

Technical Field

[0001] The present invention belongs to the field of acoustics, relates to the field of underwater acoustic signal processing, and particularly relates to an auxiliary guiding and tracking method. Background Art

[0002] When conducting a review and analysis of experimental data, if the data has a strong interference background and the target radiation noise is extremely weak, phenomena such as visible to the human eye but the tracking trajectory deviating from the true target trajectory and tracking interruption often occur, making it difficult to effectively and continuously track the target, and further leading to difficulties in subsequent data analysis.

[0003] Currently, target tracking functions have been realized in the fields of signal processing and data analysis. Classical target tracking is to obtain an azimuth history map through spatial energy spectrum estimation based on the data obtained by a sensor array, search for the maximum value near the azimuth of interest, and form a target trajectory through time accumulation. However, due to the existence of strong interference, although the general tracking method can search for the maximum value, the trajectory will still deviate and be interrupted during the tracking process. Therefore, it is very difficult for the general tracking method to handle the trajectory tracking of strong interference and weak targets. Therefore, there is an urgent need for a stable, continuous and effective tracking method. Summary of the Invention

[0004] The purpose of the present invention is to provide an auxiliary guiding and tracking method to solve the problems of trajectory deviation and interruption of the existing tracking method under strong interference and weak targets in the background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] An auxiliary guiding and tracking method, comprising the following steps: Step 1, an analyst observes the azimuth history map, selects the target to be tracked, and obtains the current target beam and the current target beam number; at least 2 trajectory points are selected and marked on the target trajectory; Step 2, the marked points are interpolated according to the output frequency of the target precise measurement azimuth to form an auxiliary tracking guiding line composed of several guiding points; Step 3, n adjacent beams are selected on each of the left and right sides of the current target beam, interpolation is performed on the current target beam and the selected adjacent beams, and the current target precise measurement azimuth is calculated; Step 4, calculate the difference between the current target precise measurement azimuth and the current guiding azimuth, compare it with a preset angle threshold, and update the current target tracking output azimuth and the next target beam based on the target update strategy of the comparison result; Step 5, update the current guiding azimuth to the next guiding azimuth, use the next target beam as the current target beam and return to Step 3.

[0007] Preferably, in the Step 3, the interpolation is parabolic interpolation.

[0008] Preferably, n = 1 or 2.

[0009] Preferably, based on the comparison result, the target update strategy updates the current target tracking output azimuth and the next target beam as follows:

[0010] When the difference is less than or equal to the preset angle comparison threshold, the next target beam is the beam corresponding to the maximum value among the current target beam and the selected adjacent beams; when the difference is greater than the preset angle comparison threshold, the current target tracking output azimuth is assigned the current guiding azimuth, and the next target beam is the beam corresponding to the current guiding azimuth.

[0011] Preferably, in step 1, multiple markings are made at the turning points of the trajectory.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] By adopting the technical solution of the present invention, it is possible to accurately track the target by using manual assisted guidance during data review and analysis, and even in a strong interference background, even if the target is very weak, the target tracking can be smoothly carried out, avoiding phenomena such as tracking deviation from the true trajectory and false tracking in the traditional method. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a flowchart of assisted guidance tracking.

[0015] Figure 2 is an example diagram of intermittent interference tracking.

[0016] Figure 3 is an example diagram of strong interference tracking in adjacent azimuths.

[0017] Figure 4 is an example diagram of tracking deviation of intersecting trajectories. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Hereinafter, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] Figure 1 shows an assisted guidance tracking method. Referring to Figure 1 as shown, the method specifically includes the following 5 steps.

[0020] Step 1: The analyst observes the azimuth history diagram, moves the cursor to select the target to be tracked, obtains the initial target beam and the initial beam number K0, takes the initial target beam as the current target beam, and takes this initial beam number as the current target beam number; then selects at least 2 trajectory points on the target trajectory and marks them. Here, the marked trajectory points are preferably throughout the entire trajectory, especially mark multiple times at the inflection points of the trajectory, and then enter Step 2 for automatic target tracking.

[0021] Step 2: Interpolate the marked points according to the output frequency of the target precise measurement azimuth to form an auxiliary tracking guiding line composed of several guiding points.

[0022] In Step 2 of the present invention, interpolate the marked points, take the interpolation points and the marked points as guiding points, and form an auxiliary tracking guiding line by all the guiding points. The number of these guiding points is consistent with the output frequency of the target precise measurement azimuth; it should be noted here that the auxiliary tracking guiding line is a series of points, not a single line. Since there are many points, it is approximately a line.

[0023] Step 3: Select 1 adjacent beam K0 - 1 and K0 + 1 on each side of the current target beam K0, perform parabolic interpolation on the azimuths Y(K0 - 1), Y(K0), and Y(K0 + 1) of the adjacent beam and the current target beam at the current moment, and calculate the current target precise measurement azimuth θ1.

[0024] In Step 3 of the present invention, the calculation formula for the current target precise measurement azimuth θ1 is as follows:

[0025]

[0026] In the formula, θ0 is the beam interval, Δθ is the angle deviation, K0 is the beam number of the current target beam, and P(K0) represents the azimuth of the current target beam K0 at the current moment.

[0027] In Step 3 of the present invention, Y(K0 - 1), Y(K0), and Y(K0 + 1) are at the same time point, that is, in the azimuth history diagram, they are on the same horizontal axis, but their azimuths are different.

[0028] Step 4: Calculate the difference |θ2 - θ1| between the current target precise measurement azimuth θ1 and the current guiding azimuth θ2, and compare it with the preset angle threshold θ th Compare, and update the current target tracking output azimuth and the next target beam based on the target update strategy of the comparison result.

[0029] In Step 4 of the present invention, the current guiding azimuth is the point on the auxiliary tracking guiding line, and this current guiding azimuth, the current target precise measurement azimuth, Y(K0 - 1), Y(K0), and Y(K0 + 1) are all at the same time point (on the same horizontal axis).

[0030] The specific target update strategy is as follows: If the difference is less than or equal to the preset angle comparison threshold, the value of the next target beam is set to the maximum value among Y(K0-1), Y(K0), and Y(K0+1). That is, if the value Y(K0-1) of beam K0-1 is the largest, the value of the next target beam is Y(K0-1); if the difference is greater than the preset angle comparison threshold, the current target fine measurement azimuth θ1 is assigned the current guiding azimuth θ2, denoted as θ1 = θ2, and the value of the next target beam is the current guiding azimuth θ2.

[0031] Step 5: Update the current guiding azimuth to the next guiding azimuth, use the next target beam as the current target beam, and return to Step 3.

[0032] It should be noted here that, for example, if the current target beam in Steps 1-3 is the target beam at t = 100, in Step 4, if the difference |θ2 - θ1| is less than the preset angle comparison threshold, then update the next target beam to the target beam at t = 101. If it is found that the maximum value among Y(K0-1), Y(K0), and Y(K0+1) is Y(K0-1), then simultaneously update the value of the target beam at t = 101 to Y(K0-1); if the difference |θ2 - θ1| is greater than the preset angle comparison threshold, then update the next target beam to the target beam at t = 101, and simultaneously update the value of the target beam at t = 101 to θ2.

[0033] In Step 5 of the present invention, the next guiding point is the azimuth angle corresponding to the point on the auxiliary tracking guiding line at t = 101.

[0034] In the present invention, a trigger condition for ending target automatic tracking can be set. During the repeated execution of Steps 3-5, when the trigger condition is reached, the target automatic tracking is automatically ended.

[0035] In the embodiment of the present invention, for the selected target beam, obtain its two adjacent beams for parabolic interpolation, calculate and output the fine measurement azimuth, calculate the difference between the fine measurement azimuth and the guiding azimuth, judge the size of the difference and the angle threshold, and select the target beam for the next batch of tracking. If the difference is greater than the threshold, reassign the fine measurement azimuth to the corresponding guiding azimuth value, and select the beam corresponding to the guiding azimuth as the target beam for the next batch; otherwise, determine the target beam for the next batch of tracking according to the sizes of the selected beam and its adjacent beams.

[0036] As Figure 2 shown, through actual data analysis, an azimuth history diagram of a target with strong intermittent interference is given, an auxiliary guiding line is formed through trajectory annotation, and the tracking result of the auxiliary guiding tracking method is obtained according to the Figure 1 process. From Figure 2(c) It can be seen that even in the presence of intermittent strong interference, the auxiliary guidance tracking method can still track such targets more accurately.

[0037] As Figure 3 shown, by analyzing actual data, an azimuth history diagram of a target with strong adjacent interference is given. An auxiliary guidance line is formed through trajectory annotation, and the tracking result of the auxiliary guidance tracking method is obtained according to the Figure 1 process. From Figure 3 (c) It can be seen that in the case of strong interference in the adjacent azimuth, the traditional method fails to track the target correctly, while the auxiliary guidance tracking method can still track the target correctly.

[0038] As Figure 4 shown, by analyzing actual data, an azimuth history diagram of a target whose trajectory intersects with that of other targets is given. An auxiliary guidance line is formed through trajectory annotation, and the tracking result of the auxiliary guidance tracking method is obtained according to the Figure 1 process. From Figure 4 (c) It can be seen that at the intersection point, the traditional method deviates from the correct trajectory in target tracking, while the auxiliary guidance tracking method can still accurately track the target.

Claims

1. An auxiliary guidance and tracking method, characterized in that, It includes the following steps: Step 1: The analyst observes the azimuth history diagram, moves the cursor to select the target to be tracked, obtains the initial target beam and the initial beam number K0, takes the initial target beam as the current target beam, and takes this initial beam number as the current target beam number; select at least 2 trajectory points on the target trajectory and mark them. Step 2: Interpolate the marked points according to the output frequency of the target refined measurement azimuth to form an auxiliary tracking guiding line composed of several guiding points. Step 3: Select 1 adjacent beam K0 - 1 and K0 + 1 on each side of the current target beam K0, perform parabolic interpolation on the azimuths Y(K0 - 1), Y(K0), and Y(K0 + 1) of the adjacent beam and the current target beam at the current moment, and calculate the current target refined measurement azimuth θ1. In Step 3, the calculation formula for the current target refined measurement azimuth θ1 is as follows: ， In the formula, θ0 is the beam interval, Δθ is the angle deviation, K0 is the beam number of the current target beam, and P(K0) represents the azimuth of the current target beam K0 at the current moment. Step 4, calculate the difference |θ2 - θ1| between the current target precise measurement azimuth θ1 and the current guidance azimuth θ2, and compare it with the preset angle threshold θ th Compare, and update the current target tracking output azimuth and the next target beam based on the target update strategy of the comparison result; In Step 4, the current guiding azimuth is the point on the auxiliary tracking guiding line, and this current guiding azimuth, the current target refined measurement azimuth, Y(K0 - 1), Y(K0), and Y(K0 + 1) are all at the same time point. Step 5: Update the current guiding azimuth to the next guiding azimuth, take the next target beam as the current target beam, and return to Step 3.

2. The auxiliary guiding and tracking method according to claim 1, characterized in that In the said Step 4, update the current target tracking output azimuth and the next target beam based on the target update strategy of the comparison result as: When the difference is less than or equal to the preset angle comparison threshold, set the value of the next target beam to the maximum value among Y(K0 - 1), Y(K0), and Y(K0 + 1); if the difference is greater than the preset angle comparison threshold, assign the current target refined measurement azimuth θ1 to the current guiding azimuth θ2, denoted as θ1 = θ2, and the value of the next target beam is the current guiding azimuth θ2.

3. The auxiliary guiding and tracking method according to claim 1, characterized in that, In the said Step 1, mark the trajectory inflection points multiple times.

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