Device and method for realizing multi-aperture coaxiality based on back scattered light of atmospheric illumination

Abstract

The invention discloses a device and a method for realizing multi-aperture coaxiality based on back scattering light of atmospheric illumination. The device comprises a laser, an emission aperture, a detection aperture and an imaging system, pulse laser emitted by the laser enters the emission aperture, passes through the single-aperture telescope, and is emitted into the atmosphere after the emission direction is adjusted by the light beam deflection scanning device; the detection aperture is responsible for receiving atmospheric illumination backscattered light at a specified distance and receiving target reflected light reflected by a target; atmospheric illumination backscattered light from the detection aperture enters the imaging system and then is converged by the convergent lens to enter the imaging camera, focusing light spots are formed on the target surface of the imaging camera, and according to the positions of the focusing light spots of the imaging camera, a multi-aperture telescope optical axis fine adjusting device of the detection aperture is adjusted by an algorithm until all the focusing light spots coincide, so that the imaging system is formed. And the coaxial detection aperture is realized. According to the technical scheme, the structure is simple, cost is low, and implementation is easy.

Description

Technical Field

[0001] The present invention belongs to the field of applied optics in optical engineering, and in particular relates to a device and method for realizing multi-aperture coaxiality based on atmospheric illumination backscattered light. Background Art

[0002] Multi-aperture synthesis technology can effectively increase the laser emission power or receiving power, and is widely used in optoelectronic detection, lidar, space laser communication and other fields. The multi-aperture synthesis scanning detection system consists of an optical multi-aperture and a beam deflector. The optical multi-aperture can effectively improve the imaging resolution and detection distance of the system through multi-aperture synthesis detection. At the same time, the multi-aperture can achieve large-angle rapid scanning detection through the beam deflector. During the large-angle scanning process of the multi-aperture synthesis detection system, the optical axes of all emission apertures and detection apertures are changing rapidly. Due to the processing, adjustment and control errors between the sub-apertures, it is inevitable that there will be optical axis errors between the apertures during the scanning process, which ultimately leads to the non-confocality of the synthetic imaging of the sub-apertures of the multi-aperture synthesis scanning detection system, and the inability to synthesize the imaging in real time, which in turn limits the imaging resolution and detection distance of the system. Summary of the invention

[0003] In view of this, the technical problem to be solved by the present invention is: to create a large-angle beacon light to perform real-time calibration on the optical axes of each sub-aperture of the multi-aperture synthetic scanning detection system, and to overcome the problem of inconsistent optical axes between multiple apertures that occurs during the large-angle scanning process of the multi-aperture synthetic scanning detection system. Without adding external devices, the emission aperture pulse light source is used for active illumination, and the atmospheric illumination backscattered light at a specified distance during the pulse light beam transmission to the target is collected as the beacon light, so as to complete the adjustment of the detection aperture optical axis, so as to realize the active coaxial detection function.

[0004] The present invention provides a device and method for realizing multi-aperture coaxiality based on atmospheric illumination backscattered light, specifically:

[0005] A device for realizing multi-aperture coaxiality based on atmospheric illumination backscattered light, comprising a laser, a transmitting aperture, a detecting aperture and an imaging system, wherein a pulsed laser is emitted from the laser, enters the atmosphere through the transmitting aperture, then returns to the detecting aperture, and finally enters the imaging system;

[0006] The emission aperture is composed of a single-aperture telescope and a beam deflection scanning device. The pulsed laser emitted by the laser enters the emission aperture, passes through the single-aperture telescope, and is adjusted in the emission direction by the beam deflection scanning device before being emitted into the atmosphere, forming a beacon at a specified distance, and then continues to propagate until it irradiates the target.

[0007] The detection aperture is composed of a multi-aperture telescope and a beam deflection scanning device, which is responsible for receiving the atmospheric illumination backscattered light at a specified distance and the target reflected light reflected from the receiving target, and changes the detection direction through the beam deflection scanning device to capture the atmospheric illumination backscattered light and the target reflected light. After passing through the beam deflection scanning device, the atmospheric illumination backscattered light and the target reflected light enter the imaging system through the multi-aperture telescope;

[0008] The imaging system consists of a converging lens and an imaging camera. After the atmospheric illumination backscattered light from the detection aperture enters the imaging system, it is converged by the converging lens and enters the imaging camera, forming a focused spot on the target surface of the imaging camera. According to the position of the focused spot of the imaging camera, the algorithm adjusts the multi-aperture telescope optical axis fine adjustment device of the detection aperture until all focused spots coincide, at which time the emission aperture is coaxial with the detection aperture optical axis; subsequently, after the target reflected light enters the imaging camera, a focused spot is formed on the target surface of the imaging camera. After analyzing and calculating the focused spot, the target information is obtained, completing the multi-aperture coaxial detection of the target.

[0009] A method for realizing multi-aperture coaxial based on atmospheric illumination backscattered light, the method comprising the following steps:

[0010] A pulsed laser is emitted to illuminate the target, forming a beacon at a specified distance, and then continues to propagate until it illuminates the target, and the detection aperture receives the backscattered light of the atmospheric illumination at the specified distance;

[0011] After the atmospheric illumination backscattered light of the detection aperture enters the imaging camera through the converging lens, the atmospheric illumination backscattered light forms a focused light spot on the target surface of the imaging camera;

[0012] According to the position of the imaging camera's focused light spot, the algorithm adjusts the multi-aperture telescope optical axis fine adjustment device of the detection aperture until all the focused light spots coincide, at which point the emission aperture is coaxial with the detection aperture optical axis;

[0013] Subsequently, after the target reflected light enters the imaging camera, a focused light spot is formed on the target surface of the imaging camera. After analyzing and calculating the focused light spot, the target information is obtained, completing the multi-aperture coaxial detection of the target.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The present invention ingeniously utilizes the atmospheric illumination backscattered light during the transmission of the existing pulse illumination beam in the system to realize the coaxiality of the emission aperture and the detection aperture, and can realize multi-aperture optical axis error detection without adding equipment. It has the advantages of simple structure, cost saving, and easy implementation.

[0016] (2) The present invention uses the atmospheric illumination backscattered light during the transmission of the existing pulse illumination beam in the system to calibrate the optical axis error of the multi-aperture system, and uses the time difference between the backscattered light and the target echo to achieve integrated optical axis calibration and target detection.

[0017] (3) The present invention can change the exposure time of the optical axis camera according to the actual target distance, and freely control the beacon light generation distance and sampling thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of emitting illumination pulse laser and receiving target reflected light and atmospheric illumination backscattered light in a method and device for realizing multi-aperture coaxiality based on atmospheric illumination backscattered light of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described below with reference to the accompanying drawings and specific implementation schemes, but the protection scope of the present invention should not be limited thereto.

[0020] Figure 1 It is a schematic diagram of emitting pulsed illumination laser and receiving target reflected light and atmospheric illumination backscattered light in a method and device for realizing multi-aperture coaxiality based on atmospheric illumination backscattered light of the present invention.

[0021] like Figure 1 As shown, a device for realizing multi-aperture coaxiality based on atmospheric illumination backscattered light according to an embodiment of the present invention includes a laser, an emission aperture, a detection aperture and an imaging system. A pulsed laser is emitted from the laser, enters the atmosphere through the emission aperture, then returns to the detection aperture, and finally enters the imaging system. After the laser emits a pulsed laser, after a time equal to twice the beacon distance divided by the speed of light, the atmospheric illumination backscattered light reaches the detection aperture and enters the imaging system to assist in adjusting the coaxiality; after the laser emits a pulsed laser, after a time equal to twice the target distance divided by the speed of light, the target reflected light reaches the detection aperture and enters the imaging system to provide target information; then the laser emits the next pulsed laser, and the system continues to receive the atmospheric illumination backscattered light and the target reflected light.

[0022] The transmitting aperture is composed of a single-aperture telescope and a beam deflection scanning device. The pulsed laser emitted by the laser enters the transmitting aperture and passes through the single-aperture telescope. The transmitting direction is adjusted by the beam deflection scanning device and then emitted into the atmosphere, forming a beacon at a specified distance, and then continues to propagate until it shines on the target.

[0023] The detection aperture is composed of a multi-aperture telescope and a beam deflection scanning device. It is responsible for receiving the atmospheric illumination backscattered light at a specified distance and the target reflected light reflected from the receiving target. The detection direction is changed through the beam deflection scanning device to capture the atmospheric illumination backscattered light and the target reflected light. The atmospheric illumination backscattered light reaches the detection aperture earlier than the target reflected light. The atmospheric illumination backscattered light will enter the detection aperture and then enter the imaging system to provide coaxial adjustment information for the imaging system. The optical axis error of each aperture is reflected by the imaging camera, and the coaxiality of the transmitting aperture and the detection aperture is achieved by using the multi-aperture telescope optical axis fine adjustment device. Then the target reflected light reaches the detection aperture, and the imaging system receives the target reflected light to complete the detection of the target. After passing through the beam deflection scanning device, the atmospheric illumination backscattered light and the target reflected light enter the imaging system through the multi-aperture telescope.

[0024] The beam deflection scanning devices in the emission aperture and the detection aperture can use devices such as prisms, fast reflection mirrors or liquid crystal phased arrays to control the emission and reception directions of the laser.

[0025] Single-aperture telescopes and multi-aperture telescopes use beam deflection scanning devices for coarse adjustment of the optical axis, and also use fast mirrors, MEMS and other optical axis fine adjustment devices for fine adjustment of the optical axis. The two constitute a coarse-fine composite structure to achieve large-angle two-dimensional fine movement of the optical axis in the vertical plane and accurately control the optical axis direction of the emitting aperture and the detection aperture.

[0026] The imaging system is composed of a converging lens and an imaging camera. After the atmospheric illumination backscattered light from the detection aperture enters the imaging system, it is converged by the converging lens and enters the imaging camera. The atmospheric illumination backscattered light provides the optical axis direction of the detection aperture. The gating time of the imaging camera is set according to the arrival time of the atmospheric illumination backscattered light and the target reflected light. After the atmospheric illumination backscattered light of the detection aperture enters the imaging camera through the converging lens, the atmospheric illumination backscattered light forms a focused light spot on the target surface of the imaging camera. According to the position of the focused light spot of the imaging camera, the algorithm adjusts the multi-aperture telescope optical axis fine adjustment device of the detection aperture until all the focused light spots coincide, and the emission aperture is coaxial with the detection aperture optical axis. Subsequently, after the target reflected light enters the imaging camera, a focused light spot is formed on the target surface of the imaging camera. After analyzing and calculating the focused light spot, the target information is obtained, and the multi-aperture coaxial detection of the target is completed. Those skilled in the art can select any algorithm to analyze and calculate the focused light spot, and the coaxial detection process is also a familiar content to those skilled in the art.

[0027] According to an embodiment of the present invention, a method for realizing multi-aperture coaxial based on atmospheric illumination backscattered light is provided, the method comprising the following steps:

[0028] A pulsed laser is emitted to illuminate the target, forming a beacon at a specified distance, and then continues to propagate until it illuminates the target, and the detection aperture receives the backscattered light of the atmospheric illumination at the specified distance;

[0029] After the atmospheric illumination backscattered light of the detection aperture enters the imaging camera through the converging lens, it forms a focused light spot on the target surface;

[0030] According to the position of the imaging camera's focused light spot, the algorithm adjusts the multi-aperture telescope optical axis fine adjustment device of the detection aperture until all the focused light spots coincide, at which point the emission aperture is coaxial with the detection aperture optical axis;

[0031] Subsequently, after the target reflected light enters the imaging camera, a focused light spot is formed on the target surface of the imaging camera. After analyzing and calculating the focused light spot, the target information is obtained, completing the multi-aperture coaxial detection of the target.

[0032] In one embodiment, the emitted laser light is pulsed light.

[0033] In one embodiment, the imaging system can first receive the atmospheric illumination backscattered light at a specified distance and then receive the target reflected light of the multi-path detection aperture by controlling the gating time during the large-angle scanning process. By receiving the atmospheric illumination backscattered light, the optical axis distribution of the multi-path detection aperture can be obtained, and the deflection of the optical axis direction of each detection aperture can be controlled by the optical axis distribution to form a multi-path coaxial point, thereby achieving the coaxiality of the multi-path detection aperture, as described in the above method steps. By controlling the gating time to receive the target reflected light of the multi-path detection aperture, the synthetic detection of the target can be completed.

[0034] According to the above description, by controlling the gating time, the detection aperture can first receive the backscattered light of the atmospheric illumination to complete the coaxial adjustment, and then receive the target reflected light to realize multi-aperture coaxial detection.

[0035] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A device for realizing multi-aperture coaxiality based on atmospheric illumination backscattered light, characterized in that: It includes a laser, a transmitting aperture, a detecting aperture and an imaging system. The pulsed laser is emitted from the laser, enters the atmosphere through the transmitting aperture, then returns to the detecting aperture, and finally enters the imaging system. The emission aperture is composed of a single-aperture telescope and a beam deflection scanning device. The pulsed laser emitted by the laser enters the emission aperture, passes through the single-aperture telescope, and is adjusted in the emission direction by the beam deflection scanning device before being emitted into the atmosphere, forming a beacon at a specified distance, and then continues to propagate until it irradiates the target. The detection aperture is composed of a multi-aperture telescope and a beam deflection scanning device, which is responsible for receiving the atmospheric illumination backscattered light at a specified distance and the target reflected light reflected from the receiving target, and changes the detection direction through the beam deflection scanning device to capture the atmospheric illumination backscattered light and the target reflected light. After passing through the beam deflection scanning device, the atmospheric illumination backscattered light and the target reflected light enter the imaging system through the multi-aperture telescope; The imaging system consists of a converging lens and an imaging camera. After the atmospheric illumination backscattered light from the detection aperture enters the imaging system, it is converged by the converging lens and enters the imaging camera, forming a focused spot on the target surface of the imaging camera. According to the position of the focused spot of the imaging camera, the algorithm adjusts the multi-aperture telescope optical axis fine adjustment device of the detection aperture until all focused spots coincide, at which time the emission aperture is coaxial with the detection aperture optical axis; subsequently, after the target reflected light enters the imaging camera, a focused spot is formed on the target surface of the imaging camera. After analyzing and calculating the focused spot, the target information is obtained, completing the multi-aperture coaxial detection of the target.

2. The device for realizing multi-aperture coaxiality based on atmospheric illumination backscattered light according to claim 1, characterized in that: After the laser emits a pulsed laser, the backscattered light from the atmospheric illumination reaches the detection aperture after a time equal to twice the beacon distance divided by the speed of light.

3. The device for realizing multi-aperture coaxial based on atmospheric illumination backscattered light according to claim 1, characterized in that: After the laser emits a pulsed laser, after a time equal to twice the target distance divided by the speed of light, the target reflected light reaches the detection aperture.

4. The device for realizing multi-aperture coaxial based on atmospheric illumination backscattered light according to claim 1, characterized in that: The beam deflection scanning devices in the emission aperture and the detection aperture use prisms, fast reflection mirrors or liquid crystal phased arrays to control the emission and reception directions of the laser.

5. The device for realizing multi-aperture coaxiality based on atmospheric illumination backscattered light according to claim 1, characterized in that: The optical axis fine adjustment device includes a fast reflection mirror, MEMS, a beam deflection scanning device and an optical axis fine adjustment device to form a coarse-fine composite structure, which can realize large-angle two-dimensional fine movement of the optical axis in the vertical plane and accurately control the optical axis direction of the emission aperture and the detection aperture.

6. A method for realizing multi-aperture coaxial based on atmospheric illumination backscattered light, performed by the device for realizing multi-aperture coaxial based on atmospheric illumination backscattered light according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: The pulsed laser is emitted to illuminate the target, forming a beacon at a specified distance, and then continues to propagate until it shines on the target. The detection aperture receives the backscattered light of the atmospheric illumination at the specified distance and the target reflected light reflected from the target; After the atmospheric illumination backscattered light of the detection aperture enters the imaging camera through the converging lens, it forms a focused light spot on the target surface of the imaging camera; According to the position of the imaging camera's focused light spot, the algorithm adjusts the multi-aperture telescope optical axis fine adjustment device of the detection aperture until all the focused light spots coincide, at which point the emission aperture is coaxial with the detection aperture optical axis; Subsequently, after the target reflected light enters the imaging camera, a focused light spot is formed on the target surface of the imaging camera. After analyzing and calculating the focused light spot, the target information is obtained, completing the multi-aperture coaxial detection of the target.

7. The method for realizing multi-aperture coaxial based on atmospheric illumination backscattered light according to claim 6, characterized in that: During large-angle scanning, the imaging system first receives the backscattered light of the atmospheric illumination at a specified distance by controlling the gating time, and then receives the reflected light of the target.

8. The method for realizing multi-aperture coaxial based on atmospheric illumination backscattered light according to claim 6, characterized in that: Also includes: The backscattered light of atmospheric illumination is received to obtain the optical axis distribution of the multi-path detection apertures. The deflection of the optical axis direction of each detection aperture is controlled by the optical axis distribution, thereby achieving the coaxiality of the multi-path detection apertures.

9. The method for realizing multi-aperture coaxial based on atmospheric illumination backscattered light according to claim 6, characterized in that: After the pulsed laser is emitted, the backscattered light from the atmospheric illumination reaches the detection aperture after a time equal to twice the beacon distance divided by the speed of light.

10. The method for realizing multi-aperture coaxial based on atmospheric illumination backscattered light according to claim 6, characterized in that: After emitting a pulsed laser, the target reflected light reaches the detection aperture after a time equal to twice the target distance divided by the speed of light.

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