Self-adjusting method for achieving stable tracking and ranging based on Gaussian approximation of laser optical axis

Abstract

The present invention discloses a self - adjustment method for achieving stable tracking and ranging based on Gaussian approximation of the laser optical axis. A set of data distributed according to the Gaussian distribution is randomly generated through a Gaussian surface. By controlling the offset of the laser optical axis for each group of data, a group of data is randomly selected, and laser ranging is performed according to the data distribution position. By detecting whether data is returned, if data is returned, the adjustment of the laser beam is stopped; if no data is returned, other groups of data are randomly selected. If during the ranging process, the laser ranging changes from having data returned to having no data returned, at this time, by adjusting the variance of the Gaussian surface, the randomly generated data distribution becomes more concentrated at the position where the data is lost, and the offset of the laser optical axis is controlled again according to the above process until data is returned by the laser ranging. Through the method of the present invention, the missing measurement rate of the laser rangefinder can be effectively reduced, and the visual field tracking center can be re - corrected in the case of the loss of target tracking and ranging, so as to achieve stable tracking and ranging of the laser rangefinder.

Description

Technical Field

[0001] The present invention relates to the technical field of lasers, and specifically to a self - adjustment method for stable tracking and ranging based on Gaussian approximation of the laser optical axis. Background Art

[0002] Two - dimensional data following a Gaussian surface distribution has the following characteristics: the distribution of points closer to the center is denser, and the distribution of points farther from the center is sparser; the smaller the variance of the Gaussian surface, the more the points' distribution clusters towards the center.

[0003] The Gaussian surface expression is as follows:

[0004]

[0005] The Gaussian surface graphs corresponding to different variances are as Figures 1-3 shown; from the Figures 1-3 three groups of two - dimensional Gaussian surface surfaces in, the smaller the variance value, the more its distribution clusters towards the center. According to the above characteristics, Gaussian surfaces with different variance values are used to approximate the optical axis center of the laser rangefinder, and the offset is gradually reduced to achieve stable ranging of the laser rangefinder.

[0006] In a general laser ranging and tracking system, first, an optoelectronic device detects a target. After the optoelectronic device detects the target, the servo system and the image processing system output the target azimuth and elevation information. By adjusting the laser optical axis to be parallel to the optical axis center of the optical field, the laser rangefinder is controlled to range on the target, and the three - dimensional information of the target is obtained. In an engineering system, the optical axes of the two will have a certain angle due to the influence of environmental factors such as temperature, transportation, vibration, etc., and assembly errors, and this angle will have a certain impact on the ranging performance of long - distance targets. Summary of the Invention

[0007] The purpose of the present invention is to provide a self - adjustment method for stable tracking and ranging based on Gaussian approximation of the laser optical axis, which uses the method of dynamically adjusting the tracking center of the optical field to eliminate the influence of environmental factors such as temperature, transportation, vibration, etc., and assembly errors on the deviation of the laser optical axis, so as to solve the problems raised in the above background art.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] A self - adjustment method for stable tracking and ranging based on Gaussian approximation of the laser optical axis, comprising the following steps:

[0010] S1: Randomly generate a set of data following a Gaussian distribution through a Gaussian surface;

[0011] S2: Control the laser optical axis offset amount for each group of data, and randomly select a set of data;

[0012] S3: Perform laser ranging according to the data distribution position;

[0013] S4: By detecting whether data is returned, if data is returned, stop adjusting the laser beam, and if no data is returned, randomly select other groups of data;

[0014] S5: If during the ranging process, the laser ranging changes from having data returned to having no data returned, then at this time, adjust the variance of the Gaussian surface to make the randomly generated data distribution more concentrated at the position of the lost data;

[0015] S6: Re-control the laser optical axis offset according to the above process until data is returned from the laser ranging.

[0016] Furthermore, utilize the distribution characteristics of the Gaussian surface to achieve automatic approximation and adjustment of the laser optical axis to realize stable tracking ranging.

[0017] Furthermore, the more specific steps are as follows:

[0018] S1: When the system is in the target tracking state, first randomly generate a set of 100 random points centered on the yellow point, which satisfy the Gaussian distribution with a variance of 5;

[0019] S2: Control the optical field offset according to the distribution of the points, thereby adjusting the tracking center of the optical field to determine whether the laser rangefinder returns data. Assume that the laser rangefinder returns data when detected at the yellow point, which means that when the offset is adjusted to the coordinates of the blue point, the relative offset between the target and the optical axis center of the laser rangefinder is small at this time, and fix the tracking offset as the coordinates of the blue point;

[0020] S3: As the target moves, if the distance value can always be measured, there is no need to adjust the offset of the field of view tracking center. As time goes by, there will be a situation where no distance value is returned. At this time, it is necessary to re-adjust the offset of the field of view tracking center and randomly generate a set of 100 random points centered on the blue point, which satisfy the Gaussian distribution with a variance of 2. Since the variance is smaller, the generated points of the sample are more concentrated around the blue point;

[0021] S4: Centered on the blue point, control the field of view tracking offset according to the coordinates of the random points in the generated distribution map. Assume that the laser rangefinder returns data when detected at the red point, which means that when the offset is adjusted to the coordinates of the red point, the relative offset between the target and the optical axis center of the laser rangefinder is small at this time, and fix the tracking offset as the coordinates of the red point;

[0022] S5: Repeat the above steps S3 and S4, just adjust the generated random numbers to make them satisfy the two-dimensional Gaussian distribution with a variance of 1 random data;

[0023] S6: Through the approximation of multiple two-dimensional Gaussians, the offset of the field of view tracking center is dynamically adjusted to achieve stable tracking and ranging of moving targets.

[0024] Furthermore, by generating two-dimensional data distributed according to a Gaussian surface at the pseudo center, using this data to control the offset of the laser optical axis, and gradually adjusting the variance of the Gaussian surface distribution, the two-dimensional data of the distribution gradually approaches the true target center, thereby realizing the function of stable tracking and ranging.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] The self-adjustment method for stable tracking and ranging based on Gaussian approximation of the laser optical axis provided by the present invention. Its conventional tracking and ranging method corrects the optical axes of the optical system and the laser rangefinder by adjusting the offset of the tracking center to achieve tracking and ranging. The offsets Δx and Δy of servo tracking are determined through multiple experiments, and the center offset is corrected with this value. It can achieve better tracking and ranging in the case of fixed targets and long-distance targets. However, once the target to be measured is a high-speed moving target at close range or the target heading changes, a high missed detection rate will occur. The present invention generates two-dimensional data distributed according to a Gaussian surface at the pseudo center, uses this data to control the offset of the laser optical axis, and gradually adjusts the variance of the Gaussian surface distribution, so that the two-dimensional data of the distribution gradually approaches the true target center, thereby realizing the function of stable tracking and ranging and effectively reducing the missed detection rate of the laser rangefinder. Description of the Drawings

[0027] Figure 1 It is a density curve graph of the existing two-dimensional Gaussian distribution function;

[0028] Figure 2 It is a curve graph of the existing two-dimensional Gaussian distribution with a variance of 5;

[0029] Figure 3 It is a curve graph of the existing two-dimensional Gaussian distribution with a variance of 2;

[0030] Figure 4 It is a diagram of the optical field center and the laser spot position under ideal conditions of the present invention;

[0031] Figure 5 It is a diagram of the optical field center and the laser spot position at an assumed 5 km of the present invention;

[0032] Figure 6 It is a diagram of the optical field center and the laser spot position at an assumed 10 km of the present invention;

[0033] Figure 7 It is the optical field center and the laser spot position at an assumed 20 km of the present invention;

[0034] Figure 8 It is a flowchart of the method of the present invention;

[0035] Figure 9 It is a distribution diagram of two-dimensional data points with a Gaussian distribution and a variance of 5 randomly generated by the present invention;

[0036] Figure 10 It is a position diagram of the first return of the ranging value for the blue points of the present invention;

[0037] Figure 11 It is a distribution diagram of two-dimensional data points with a Gaussian distribution and a variance of 2 generated with the blue points as the center by the present invention;

[0038] Figure 12 It is a position diagram of the first return of the ranging value for the red points of the present invention;

[0039] Figure 13 It is a distribution diagram of two-dimensional data points with a Gaussian distribution and a variance of 1 generated with the red points as the center by the present invention. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0041] In the embodiments of the present invention: due to various errors in the optical axis center of the actual optical system and the laser rangefinder, there will always be a certain deviation in the actually assembled system, and as the distance increases, the distance between the center of the optical system and the spot center of the laser rangefinder will also increase, as Figures 4-7 shown.

[0042] Based on this, please refer to Figure 8 , the embodiments of the present invention provide a self-adjustment method for stable tracking ranging based on Gaussian approximation of the laser optical axis. A set of data distributed according to the Gaussian distribution is randomly generated through a Gaussian surface; the laser optical axis offset is controlled for each group of data, and a group of data is randomly selected; laser ranging is performed according to the data distribution position; by detecting whether there is data return, if there is data return, the adjustment of the laser beam is stopped, and if there is no data return, other groups of data are randomly selected; if the laser ranging changes from having data return to having no data return during the ranging process, then at this time, the variance of the Gaussian surface is adjusted to make the randomly generated data distribution more concentrated at the position where the data is lost; the laser optical axis offset is controlled again according to the above process until there is data return in the laser ranging. The present invention mainly utilizes the distribution characteristics of the Gaussian surface to automatically approximate and adjust the laser optical axis to achieve stable tracking ranging.

[0043] In order to further better explain the present invention, the following specific implementation method is also provided:

[0044] S1: When the system is tracking the target, it first randomly generates a set of random points with a sample size of 100, a Gaussian distribution, and a variance of 5, with the yellow point as the center point; Figure 10 As shown;

[0045] S2: Press Figure 10 The distribution of the midpoint controls the optical field offset, thereby adjusting the tracking center of the optical field to determine whether the laser rangefinder has return data. Assuming that the laser rangefinder has return data detected at the yellow dot, it means that when the offset is adjusted to the blue dot coordinate, the relative offset between the target and the optical axis center of the laser rangefinder is small, and the fixed tracking offset is the coordinate of the blue dot, such as Figure 11 As shown;

[0046] S3: As the target moves, if the distance value can be measured all the time, there is no need to adjust the field of view tracking center offset. As time goes by, there will be a situation where there is no return value for the distance measurement. At this time, it is necessary to readjust the field of view tracking center offset and regenerate a group of random points with a sample size of 100, satisfying the Gaussian distribution and a variance of 2, with the blue point as the center. This distribution has a smaller variance, and the samples of the generated points are more concentrated around the blue point, such as Figure 12 As shown;

[0047] S4: With the blue dot as the center, control the field tracking offset according to the coordinates of the random points in the generated distribution map. Assuming that the laser rangefinder has returned data at the red dot, it means that when the offset is adjusted to the red dot coordinate, the relative offset between the target and the optical axis center of the laser rangefinder is small. At this time, the fixed tracking offset is the coordinate of the red dot, such as Figure 13 As shown;

[0048] S5: Repeat the above steps S3 and S4, but adjust the generated random numbers to satisfy the two-dimensional Gaussian distribution and the variance is 1;

[0049] S6: Through multiple two-dimensional Gaussian approximations, the field of view tracking center offset is dynamically adjusted to achieve stable tracking and ranging of moving targets.

[0050] In summary, the self-adjusting method for realizing stable tracking and ranging based on Gaussian approximation of laser optical axis provided by the present invention generates two-dimensional data distributed according to Gaussian surface at the pseudo center, uses the data to control the offset of the laser optical axis, and gradually adjusts the variance of Gaussian surface distribution so that the distributed two-dimensional data gradually approaches the real target center, thereby realizing the stable tracking and ranging function.

[0051] As described above, it is only the preferred specific implementation manner of the present invention. However, the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. Self - adjustment method for stable tracking and ranging based on Gaussian approximation of laser optical axis, characterized in that, it includes the following steps: S1: Randomly generate a set of data distributed according to Gaussian distribution through a Gaussian surface; S2: Control the laser optical axis offset amount for each group of data, and randomly select a group of data; S3: Perform laser ranging according to the data distribution position; generate two - dimensional data distributed according to the Gaussian surface at the pseudo - center, use this data to control the laser optical axis offset amount, and gradually adjust the variance of the Gaussian surface distribution to make the distributed two - dimensional data gradually approach the real target center, thereby realizing the function of stable tracking and ranging; S4: Detect whether there is data return. If there is data return, stop adjusting the laser beam. If there is no data return, randomly select other groups of data; S5: If during the ranging process, the laser ranging changes from having data return to having no data return, then at this time, adjust the variance of the Gaussian surface to make the randomly generated data distribution more concentrated at the position where the data is lost; S6: Re - control the laser optical axis offset amount according to the above process until there is data return from the laser ranging.

2. The self - adjustment method for stable tracking and ranging based on Gaussian approximation of laser optical axis as described in claim 1, characterized in that, utilize the distribution characteristics of the Gaussian surface to achieve automatic approximation and adjustment of the laser optical axis to realize stable tracking and ranging.

3. The self - adjustment method for stable tracking and ranging based on Gaussian approximation of laser optical axis as described in claim 2, characterized in that, the more specific steps are as follows: S1: When the system is in the state of tracking the target, first randomly generate a set of 100 random points with the yellow point as the center point, which satisfy Gaussian distribution and have a variance of 5; S2: Control the optical field offset amount according to the distribution of the points, thereby adjusting the tracking center of the optical field to judge whether the laser rangefinder has return data. Assume that when it is detected that the laser rangefinder has return data at the yellow point, it means that when the offset amount is adjusted to the coordinates of the blue point, at this time, the relative offset amount between the target and the optical axis center of the laser rangefinder is small, and fix the tracking offset amount as the coordinates of the blue point; S3: As the target moves, if the distance value can always be measured, there is no need to adjust the offset amount of the field - of - view tracking center. As time goes by, there will be a situation where there is no return value for ranging. At this time, it is necessary to re - adjust the offset amount of the field - of - view tracking center, and randomly generate a set of 100 random points with the blue point as the center, which satisfy Gaussian distribution and have a variance of 2. Because the variance of this distribution is smaller, the generated points are more concentrated around the blue point; S4: With the blue point as the center, control the field - of - view tracking offset amount according to the coordinates of the random points in the generated distribution map. Assume that when it is detected that the laser rangefinder has return data at the red point, it means that when the offset amount is adjusted to the coordinates of the red point, at this time, the relative offset amount between the target and the optical axis center of the laser rangefinder is small, and at this time, fix the tracking offset amount as the coordinates of the red point; S5: Repeat the above steps S3 and S4, just adjust the generated random numbers to make them satisfy two - dimensional Gaussian distribution with a variance of 1 random data; S6: Through multiple approximations of two - dimensional Gaussian, dynamically adjust the offset amount of the field - of - view tracking center to realize stable tracking and ranging of moving targets.

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