Space target recognition enhancement method based on bionic event camera and acousto-optic modulator

Abstract

The invention discloses a space target recognition enhancement method based on a bionic event camera and an acousto-optic modulator, and relates to a space target recognition enhancement method. The objective of the invention is to solve the problem of weak recognition capability of a bionic event camera caused by low target intensity change rate in an actual visual space target recognition task. The method comprises the following steps: step 1, constructing a target background image in a spatial range according to star map distribution, and defining direction vectors and luminous intensities of different targets; 2, changing the light intensity of a target penetrating through a crystal in a light modulator according to the voltage change controlled by the acousto-optic modulator; and step 3, according to the intensity change of the space target under the action of the acousto-optic modulator, analyzing an enhanced data stream for space target imaging in the bionic event camera. The invention belongs to the technical field of visual space recognition.

Description

Technical Field

[0001] The present invention relates to a method for enhancing spatial target recognition, belonging to the technical field of visual spatial recognition. Background Art

[0002] At present, bionic event cameras based on the imaging principle of light intensity change have been applied to some extent in fields such as spacecraft target recognition. However, bionic event cameras mainly consider the light intensity change of the environment and lack the ability to recognize static targets or spatial targets with a low light intensity change rate, thus limiting the aerospace application prospects of bionic event cameras; while an acousto-optic modulator can actively change a specific wavelength band by adjusting the voltage, and can effectively adjust the light intensity of the target passing through the crystal in the acousto-optic modulator, thereby improving the imaging ability of the bionic event camera. Therefore, how to utilize the different characteristics of the acousto-optic modulator and the bionic event camera to improve the spatial target recognition ability and thus serve the navigation field is an urgent problem to be solved in the current visual spatial target recognition engineering field. Summary of the Invention

[0003] In order to solve the problem that in actual visual spatial target recognition tasks, the recognition ability of the bionic event camera is weak due to the low target intensity change rate, the present invention further provides a method for enhancing spatial target recognition based on a bionic event camera and an acousto-optic modulator.

[0004] The technical solution adopted by the present invention to solve the above problems is: the steps of the present invention include:

[0005] Step 1: Construct a target background image within a spatial range according to the star chart distribution, and define the direction vectors and luminous intensities of different targets;

[0006] Step 2: Control the voltage change by using an acousto-optic modulator to change the light intensity of the target passing through the crystal in the light modulator;

[0007] Step 3: Analyze the enhanced data stream for imaging the spatial target in the bionic event camera according to the intensity change of the spatial target under the action of the acousto-optic modulator.

[0008] Further, in Step 1, a star catalog is used to construct the distribution of the target within the spatial range. There are multiple targets in space, and the direction vector of each target in the star catalog is:

[0009]

[0010] And its corresponding light intensity is I i .

[0011] Further, in Step 2, according to the recognition of the target image by the bionic event camera, the acousto-optic modulator is used to change the intensity of the target passing through the acousto-optic modulator. Among them, constructive interference occurs between adjacent crystal planes in the acousto-optic modulator:

[0012] 2dsin(θ) = nλ (2),

[0013] In formula (2), d is the distance between adjacent planes of the crystal, θ is the scattering angle, n is an integer related to the crystal, λ is the wavelength, and the acousto-optic modulator controls the intensity of light with the corresponding wavelength through the voltage applied to the crystal, thereby changing the intensity of the target passing through the acousto-optic modulator to I'. i .

[0014] Furthermore, according to the imaging principle of the bionic event camera for the target in step 3, analyze the enhanced data stream for imaging the space target in the bionic event camera, where the imaging principle of the bionic event camera is as follows:

[0015]

[0016] In formula (3), δ is the threshold set by the bionic event camera, and then the number of events for all targets within a unit time is statistically integrated as:

[0017] N = ∑event i (4),

[0018] In formula (4), N represents the enhanced data stream.

[0019] The beneficial effects of the present invention are as follows: The present invention considers the working principles of the bionic event camera and the acousto-optic modulator, and designs a framework device integrating the bionic event camera and the acousto-optic modulator; the set integration framework device of the present invention enhances the ability of the bionic event camera to recognize targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the flowchart of the present invention;

[0021] Figure 2 is the schematic diagram of the spatial target recognition enhancement device model based on the bionic event camera and the acousto-optic modulator of the present invention;

[0022] Figure 3 is the schematic diagram of the target recognition enhancement result of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE INVENTION I: As shown in Figures 1 to 3 , a method for enhancing spatial target recognition based on a bionic event camera and an acousto-optic modulator, the specific steps include:

[0024] Step 1: Construct a target background image within the spatial range according to the star map distribution, and define the direction vectors and luminous intensities of different targets;

[0025] Use a star catalog to construct the distribution of targets within a spatial range. There are multiple targets in space, and the direction vectors of each target in the star catalog are as follows:

[0026]

[0027] The corresponding light intensity is I i ;

[0028] Step 2: Control the voltage change using an acousto-optic modulator to change the light intensity of the target passing through the crystal in the light modulator;

[0029] According to the recognition of the target image by the bionic event camera, use the acousto-optic modulator to change the intensity of the target passing through the acousto-optic modulator. Among them, constructive interference occurs between adjacent crystal planes in the acousto-optic modulator:

[0030] 2dsin(θ) = nλ (2),

[0031] In formula (2), d is the distance between adjacent crystal planes, θ is the scattering angle, n is an integer related to the crystal, λ is the wavelength, and the acousto-optic modulator controls the intensity of the light corresponding to the wavelength by the voltage applied to the crystal, thereby changing the intensity of the target passing through the acousto-optic modulator to I' i ;

[0032] Step 3: Analyze the enhanced data stream of the spatial target imaging in the bionic event camera according to the intensity change of the spatial target under the action of the acousto-optic modulator;

[0033] According to the imaging principle of the bionic event camera for the target, analyze the enhanced data stream of the spatial target imaging in the bionic event camera. The imaging principle of the bionic event camera is as follows:

[0034]

[0035] In formula (3), δ is the threshold set by the bionic event camera, and then the number of events for all targets within a unit time is statistically integrated as:

[0036] N = ∑event i (4),

[0037] In formula (4), N represents the enhanced data stream.

[0038] Embodiment

[0039] As Figure 1 shown, a spatial target recognition enhancement device based on a bionic event camera and an acousto-optic modulator includes the following steps:

[0040] S1: Construct the target background image within the spatial range according to the star chart distribution, define the direction vectors and luminous intensities of different targets, and use all the stars below the detector limiting magnitude in the publicly available SAO star catalog. The serial numbers and direction vectors of the navigation star targets in the star catalog are shown in Table 1. The direction vectors of the first to the third targets are as follows:

[0041]

[0042] Construct multiple target distribution data according to Table 1 and set the intensity I corresponding to each target i , and form the corresponding target image.

[0043] S2: Control the voltage change according to the acousto-optic modulator to change the light intensity of the target passing through the crystal in the light modulator. Among them, constructive interference occurs between adjacent crystal planes in the acousto-optic modulator:

[0044] 2dsin(θ) = nλ (2)

[0045] where d is the distance between adjacent crystal planes, θ is the scattering angle, n is an integer related to the crystal, and λ is the wavelength. The acousto-optic modulator controls the intensity of the light corresponding to the wavelength by the voltage applied to the crystal, thereby changing the intensity of the target passing through the acousto-optic modulator to I' i , and thus obtain a series of images of the light intensity change of each target under the control of the acousto-optic modulator.

[0046] S3: Analyze the enhanced data stream of imaging the spatial target in the bionic event camera according to the intensity change of the spatial target under the action of the acousto-optic modulator. The imaging principle of the bionic event camera is as follows:

[0047]

[0048] where δ is the threshold set by the bionic event camera, set to 0.005, and then count the number of events generated for all targets within a unit time of 0.1 s as

[0049] N = ∑event i (4)

[0050] where N represents the enhanced data stream.

[0051] Using the embodiment of the present invention to obtain an enhanced device for spatial target recognition based on a bionic event camera and an acousto-optic modulator, the recognition result is as Figure 3 shown. The background is gray, and the generated data is displayed in black. Under the condition of changing the target light intensity, the total number of outputs of the bionic event camera within 0.1 s is 19, and it is 0 without changing the light intensity, indicating that no event is generated.

[0052] Table 1

[0053]

[0054] As described above, it is only the preferred embodiment of the present invention, and it does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications using the above-disclosed technical content to obtain equivalent embodiments with equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention and is based on the technical essence of the present invention, within the spirit and principle of the present invention, any simple modification, equivalent replacement, and improvement made to the above embodiments still fall within the protection scope of the technical solution of the present invention.

Claims

1. A space target recognition enhancement method based on a bionic event camera and an acousto-optic modulator, characterized in that: The specific steps include: Step 1: Construct a target background image within the space range according to the star map distribution, and define the direction vector and luminous intensity of different targets; Step 2, according to the voltage change controlled by the acousto-optic modulator, the light intensity of the target passing through the crystal in the optical modulator is changed; Step 3: Analyze the enhanced data stream of the space target imaging in the bionic event camera according to the intensity change of the space target under the action of the acousto-optic modulator.

2. The method for enhancing space target recognition based on a bionic event camera and an acousto-optic modulator according to claim 1, characterized in that: In step 1, the star catalog is used to construct the distribution of the target in the space. There are multiple targets in the space, and the direction vector of each target in the star catalog is: The corresponding light intensity is I i .

3. The method for enhancing space target recognition based on a bionic event camera and an acousto-optic modulator according to claim 1, characterized in that: In step 2, according to the recognition of the target image by the bionic event camera, the intensity of the target passing through the acousto-optic modulator is changed by using the acousto-optic modulator, wherein adjacent crystal planes in the acousto-optic modulator produce constructive interference: 2dsin(θ)=nλ(2), In formula (2), d is the distance between adjacent crystal planes, θ is the scattering angle, n is an integer related to the crystal, and λ is the wavelength. The AOM controls the intensity of the corresponding wavelength light by the voltage acting on the crystal, thereby changing the intensity of the target passing through the AOM to I′ i .

4. The method for enhancing space target recognition based on a bionic event camera and an acousto-optic modulator according to claim 1, characterized in that: In step 3, according to the imaging principle of the bionic event camera on the target, the enhanced data stream of the bionic event camera on the imaging of the space target is analyzed, wherein the imaging principle of the bionic event camera is: In formula (3), δ is the threshold set by the bionic event camera, and then the number of events for all targets in unit time is calculated as follows: N=∑event i (4), In formula (4), N represents the enhanced data stream.

Images