Laser double-end blind alignment method and device for dynamic target communication

Abstract

The invention provides a laser double-end blind alignment method and device for dynamic target communication, and belongs to the field of wireless optical communication, and the device comprises a signal transmitting module and a signal receiving module. The signal transmitting module adjusts a transmitting angle according to a laser signal reflected by the signal receiving module to scan in a first-level uncertain range, and a light beam returned by the signal receiving module is aligned in the center in a photoelectric detector of the signal transmitting module; the light receiving end is adjusted to scan in a secondary uncertain range according to the laser signal emitted by the light emitting end, and the secondary uncertain range is smaller than the primary uncertain range until the laser beam emitted by the laser signal emitting module is captured; and the signal receiving module is adjusted to realize center alignment of light beams emitted by the signal receiving module and the signal emitting module and continuous tracking. According to the method, the influence of aiming errors of the receiving and transmitting ends can be overcome, an additional radio communication mode is not needed for interactive feedback in the whole process, and the safety and reliability of wireless optical communication are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless optical communication, and relates to a laser double-end blind alignment method and device for dynamic target communication, which can solve the problem that it is difficult for a laser signal transceiver to quickly capture signal light in a large blind range during dynamic movement. Background Art

[0002] In recent years, with the rapid development of space communication technology, wireless optical communication technology has been increasingly widely used. This technology is a wireless communication technology that uses laser as an information carrier to transmit information in free space. It combines the advantages of traditional optical fiber communication and microwave communication, and has the advantages of high transmission rate, large channel capacity, strong confidentiality, and strong anti-interference ability. The capture, alignment and tracking system is the premise for ensuring wireless laser communication and plays an important role in maintaining communication stability. Achieving optical path alignment between the communication devices of both parties is a key technology to ensure wireless optical communication.

[0003] Since lasers have the characteristics of strong directionality and narrow beams, in practical applications, when laser beams used for two-way communication are aligned point-to-point, their propagation in free space, such as underwater environments or atmospheric environments, will be seriously affected, such as laser intensity attenuation, beam divergence, arrival angle fluctuations, and beam drift. Therefore, laser emitting devices often control the laser beam to be as concentrated as possible to ensure that the divergence angle of the beam remains within a small range.

[0004] For a communication device in which the laser transmitting end and the laser receiving end are relatively stationary, the relative position of the receiving end can be determined in advance. However, for a communication device in which the laser transmitting end and the laser receiving end are in relative motion, how to quickly capture, align and track a narrow beam laser is an important technical requirement to ensure normal communication of the communication device. The prior art uses a scanning method that combines beacon light and signal light to capture, align and track laser beams. However, this method requires blindly scanning an uncertain area over a large area to capture the beacon light during the capture phase, which consumes a lot of time and has a low capture efficiency (Opt. Express 32 (1), 325-338 (2024)). Therefore, for the two communication ends in motion, there is an urgent need for a more efficient method to achieve fast and precise alignment between wireless optical transceivers. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes a laser double-end blind alignment method and device for dynamic target communication, which can solve the problem that the laser signal transceiver needs to capture signal light in a large blind range during dynamic movement, resulting in low capture efficiency, and can overcome the influence of the transceiver aiming error when the transceiver of a point-to-point visible light communication link moves dynamically. At the same time, there is no need to use additional radio communication methods for interactive feedback during the entire process, which improves the security and reliability of wireless optical communication.

[0006] To solve the above problems, the technical solution adopted by the present invention is:

[0007] A laser double-end blind alignment device for dynamic target communication, the laser double-end blind alignment device comprising a signal transmitting module and a signal receiving module;

[0008] The signal transmitting module includes an optical path unit a, a control unit a, and a four-quadrant detector a8. The optical path unit a includes a laser 1, a beam expander 2, a beam splitter a3, and a MEMS galvanometer a4 from front to back. The optical path unit a is used to transmit the laser signal to the target communication area after the laser 1 transmits the laser signal, and is used to receive the laser beam reflected back by the signal receiving module after adjusting the shape and emission direction of the laser beam through the beam expander 2 and the beam splitter a3. The initial installation position of the optical path unit a of the signal transmitting module and the four-quadrant detector a8 should meet the requirement that the optical path unit a of the signal transmitting module can align the laser signal reflected back by the corner reflector 7 to the center of the four-quadrant detector a8; and realize the first-level uncertain range scanning through the MEMS galvanometer a4. When the control unit a does not receive the optical laser signal, it controls the MEMS galvanometer a4 to realize the first-level uncertain range scanning; when the control unit a receives the bias voltage signal, it calculates the bias voltage signal to obtain the spot position information and the galvanometer deflection step length, and controls the MEMS galvanometer a4 to stop scanning. The four-quadrant detector a is used to detect the laser signal emitted by the beam splitter a3 and output a bias voltage signal to the control unit a. The four-quadrant detector a8 is a photoelectric detector.

[0009] The signal receiving module includes an optical path unit b, a control unit b, and a four-quadrant detector b9, wherein the optical path unit b includes a MEMS galvanometer b5, a beam splitter b6, and a corner reflector 7 from front to back. The optical path unit b is used to receive the laser signal emitted by the laser 1 of the signal transmitting module. The initial installation positions of the optical path unit b of the signal receiving module and the four-quadrant detector b9 should meet the requirement that the optical path unit b of the signal receiving module can align the laser signal emitted by the signal transmitting module to the center of the four-quadrant detector b9. The corner reflector 7 reflects a part of the laser signal back to the optical path unit a through the beam splitter b6 and the MEMS galvanometer b5 in sequence, so as to achieve simultaneous alignment of both ends, and realize secondary uncertain range scanning through the MEMS galvanometer b5. When the control unit b does not receive the laser signal, it controls the MEMS galvanometer b6 to realize secondary uncertain range scanning. When the control unit b receives the bias voltage signal, it calculates the bias voltage signal to obtain the spot position information and the galvanometer offset step length, and controls the MEMS galvanometer b6 to complete the alignment and tracking of the laser spot. The four-quadrant detector b9 is used to detect the laser signal emitted by the beam splitter b6 and output a bias voltage signal to the control unit b. The four-quadrant detector b9 is a photoelectric detector.

[0010] Furthermore, the optical path unit a and the optical path unit b together form a coaxial optical path.

[0011] Furthermore, in the optical path unit a: the laser 1 is used to receive a laser trigger signal and emit a laser beam; the beam expander 2 is used to change the diameter and divergence angle of the laser beam; the beam splitter a3 is used to split the laser beam; and the MEMS galvanometer a is used to control the laser signal for capture, alignment and tracking.

[0012] Furthermore, in the optical path unit b: the corner reflector 7 is used to control the laser beam to return from the signal receiving module to the signal transmitting module along the coaxial optical path; the beam splitter b6 is used to split the laser beam; and the MEMS galvanometer b5 is used to control the laser signal to capture, align and track.

[0013] Furthermore, the control unit a in the signal transmitting module and the control unit b in the signal receiving module have the same structure and layout, and both include a galvanometer control module, a DAC control module, a data processing module, an MCU microcontroller, and an ADC control module connected in sequence.

[0014] The control unit a in the signal transmission module includes a galvanometer control module a14, a DAC control module a13, a data processing module a12, an MCU single chip a11, and an ADC control module a10, wherein the ADC control module a10 is connected to the four-quadrant detector a8, and the galvanometer control module a14 is connected to the MEMS galvanometer a4. Specifically:

[0015] The ADC control module a10 is used to convert the three analog signals transmitted by the four-quadrant detector a8 into digital signals; the MCU single-chip computer a11 is used to output a trigger signal to the laser 1, and at the same time to calculate the position of the laser spot according to the received bias voltage signal, and calculate the galvanometer deflection step length; the data processing module a12 is used to filter the collected digital signals; the DAC control module a10 is used to output two positive and negative analog voltages to the galvanometer control module a14; the galvanometer control module a14 is used to drive the MEMS galvanometer a4 to move.

[0016] The control unit b in the signal receiving module includes a galvanometer control module b19, a DAC control module b18, a data processing module b17, an MCU single chip microcomputer b16, and an ADC control module b15 which are connected in sequence, wherein the ADC control module b15 is connected to the four-quadrant detector b9, and the galvanometer control module b19 is connected to the MEMS galvanometer b5. Specifically:

[0017] The ADC control module b15 is used to convert the three analog signals transmitted by the four-quadrant detector b9 into digital signals; the MCU single-chip computer b16 is used to calculate the position of the laser spot according to the received bias voltage signal, and calculate the galvanometer deflection step; the data processing module b17 is used to filter the collected digital signals; the DAC control module b18 is used to output two positive and negative analog voltages to the galvanometer control module b19; the galvanometer control module b19 is used to drive the MEMS galvanometer b5 to move.

[0018] A laser double-end blind alignment method for dynamic target communication is implemented based on a laser double-end blind alignment device. A signal transmitting module controls a MEMS galvanometer a4 to scan within a primary uncertainty range by detecting a laser signal returned by a signal receiving module. The primary uncertainty range is the range of the position of the signal receiving module relative to the signal transmitting module. The signal receiving module scans within a secondary uncertainty range by detecting the laser signal emitted by the transmitting module. The secondary uncertainty range is the range of the laser signal that can be reflected back by the signal receiving module. When the signal receiving module captures the laser signal, the laser signal is further aligned and tracked. Specifically, the following steps are included:

[0019] S1, first initialize the four-quadrant detector a8 and the four-quadrant detector b9, and set the threshold voltage for the voltage value output by the four-quadrant detector a8 and the four-quadrant detector b9, and then continue to initialize the MEMS galvanometer a4 and the MEMS galvanometer b5. After the initialization is completed, the MCU single-chip microcomputer a11 controls the laser 1 to emit a laser signal through the trigger signal, and the laser signal is emitted to the terminal through the beam expander 2, the beam splitter a3, and the MEMS galvanometer a4;

[0020] S2, determine whether the four-quadrant detector a8 detects the laser signal reflected by the corner reflector 7. If no laser signal is detected, the MCU single-chip computer a11 controls the MEMS galvanometer a4 to perform spiral scanning in the first-level uncertainty range according to the minimum step length of the MEMS galvanometer a4 until the four-quadrant detector a8 detects the laser signal. After the MCU single-chip computer a11 receives the bias voltage signal output by the four-quadrant detector a, it controls the MEMS galvanometer a4 to stop scanning. The first-level uncertainty range scanning ends;

[0021] S3, after the first level of uncertain range scanning is completed, the laser signal enters the signal receiving module, and the laser signal passes through the MEMS galvanometer b5 and reaches the beam splitter b5. The beam splitter b5 splits the laser signal into two beams, one beam enters the corner reflector 7, and the other beam enters the direction of the four-quadrant detector b9;

[0022] S4, determines whether the four-quadrant detector b9 detects the incident laser signal. If no laser signal is detected, the MCU single-chip computer b16 controls the MEMS galvanometer b5 to perform spiral scanning within the secondary uncertainty range according to the minimum step length of the MEMS galvanometer b5 until the four-quadrant detector b9 detects the laser signal. The data processing module b17 performs Kalman filtering on the bias voltage signal output by the four-quadrant detector b9 and sends it to the MCU single-chip computer b16. The MCU single-chip computer b16 calculates the laser spot position information and the galvanometer deflection step length, and controls the MEMS galvanometer b5 to move the laser spot to the center of the four-quadrant detector b9 and perform continuous tracking and alignment.

[0023] The MCU b16 calculates the laser spot position information, and the specific process is as follows:

[0024]

[0025] Among them, x is the offset distance of the laser spot center in the x direction relative to the center of the four-quadrant detector b9 、 б y is the offset distance of the center of the laser spot in the y direction relative to the center of the four-quadrant detector b9, X is the bias voltage signal output by the four-quadrant detector b9 in the x direction, Y is the bias voltage signal output by the four-quadrant detector b9 in the y direction, and T is the bias voltage signal output by the four-quadrant detector b9 on the entire surface of the four-quadrant detector b9. All three are output by the ADC control module b15; the ADC control module b15 sends the bias voltage signal to the chip of the MCU microcontroller b16 through SPI, and the data processing module b17 filters the input bias voltage signal.

[0026] The MCU single chip microcomputer b16 calculates the galvanometer deflection step length according to the obtained bias voltage signal, and controls the MEMS galvanometer b5 to capture, align and track the laser signal. The specific process is as follows:

[0027]

[0028] Wherein, d is the distance from the center of the light spot to the center of the four-quadrant detector b9, D is the distance from the MEMS galvanometer b5 to the optical four-quadrant detector b9, θ is the incident angle of the laser to the MEMS galvanometer b5, V represents the maximum output voltage of the DAC control module b18, and α is the maximum polarization angle of the MEMS galvanometer b5. The DAC control module b18 is used to output two positive and negative analog voltages to the galvanometer control module b19 to control the movement of the MEMS galvanometer b5; the DAC control module b18 includes a chip and a reference voltage circuit; the galvanometer control module b19 includes a chip and a reference voltage circuit; the MCU single chip microcomputer b16 sends a bias voltage signal to the chip of the DAC control module b18 through SPI, and then the DAC control module b18 outputs an analog voltage to the galvanometer control module b19 to control the movement of the galvanometer.

[0029] The beneficial effects of the present invention are:

[0030] (1) The present invention automatically calculates the deflection step length of the galvanometer by detecting the position of the laser spot and combining it with a high-precision scanning method, thereby realizing alignment and tracking of the signal receiving end;

[0031] (2) The present invention uses a high-precision galvanometer as a scanning unit. Through high-precision galvanometer control, the uncertain area is detected at the primary range level and the secondary range level. The primary range level is no longer for the receiving module detector itself, but for the entire signal receiving module. The secondary range level is the range of the laser signal that can be reflected back by the signal receiving module. The detection range is gradually reduced from the primary range level to the secondary range level, reducing the impact of blind scanning on the capture efficiency.

[0032] (3) The present invention introduces a corner reflector into the coaxial optical path design, which eliminates the need for additional radio communication for interactive feedback during the laser signal capture process, further improving the security and reliability of wireless optical communication;

[0033] (4) The present invention can reduce the influence of the transmission environment on the laser beam by filtering the bias voltage signal, which is conducive to achieving precise alignment and tracking. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of the working principle of a laser double-end blind alignment device for dynamic target communication provided in a specific embodiment of the present invention;

[0035] Figure 2 An electronic control system solution for a laser double-end blind alignment device for dynamic target communication is provided in a specific embodiment of the present invention;

[0036] Figure 3 A control flow chart of laser double-end blind alignment for dynamic target communication provided in a specific embodiment of the present invention;

[0037] Figure 4 A schematic diagram of a scanning area of ​​a laser double-end blind alignment method for dynamic target communication provided in a specific embodiment of the present invention;

[0038] Figure 5 A schematic diagram of a method for calculating a spot position detection in a laser double-end blind alignment method for dynamic target communication provided in a specific embodiment of the present invention;

[0039] Figure 6 The figures are experimental data of a laser double-end blind alignment method for dynamic target communication provided in a specific embodiment of the present invention; (a) capture efficiency comparison diagram, and (b) dynamic tracking effect diagram.

[0040] Figure 1 In the figure: 1 laser; 2 beam expander; 3 beam splitter a; 4 MEMS galvanometer a; 5 MEMS galvanometer b; 6 beam splitter b; 7 corner reflector; 8 four-quadrant detector a; 9 four-quadrant detector b; 10 ADC control module a; 11 MCU single chip computer a; 12 data processing module a; 13 DAC control module a; 14 galvanometer control module a; 15 ADC control module b; 16 MCU single chip computer b; 17 data processing module b; 18 DAC control module b; 19 galvanometer control module b. DETAILED DESCRIPTION

[0041] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. The preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] A laser double-end blind alignment device for dynamic target communication, the laser double-end blind alignment device comprises a signal transmitting module and a signal receiving module such as Figure 1 As shown;

[0043] The signal transmitting module includes an optical path unit a, a control unit a, and a photodetector a8, wherein the optical path unit a includes a laser 1, a beam expander 2, a beam splitter a3, and a MEMS galvanometer a4 from front to back. The optical path unit a is used to transmit the laser signal to the target communication area after the laser 1 transmits the laser signal, and is used to receive the laser beam reflected back by the signal receiving module after adjusting the shape and emission direction of the laser beam through the beam expander 2 and the beam splitter a3. The initial installation position of the optical path unit a of the signal transmitting module and the four-quadrant detector a should meet the requirement that the optical path unit a of the signal transmitting module can align the laser signal reflected back by the corner reflector 7 to the center of the four-quadrant detector a8; and realize the first-level uncertain range scanning through the MEMS galvanometer a4. When the control unit a does not receive the optical laser signal, it controls the MEMS galvanometer a4 to realize the first-level uncertain range scanning; when the control unit a receives the bias voltage signal, it calculates the bias voltage signal to obtain the spot position information and the galvanometer deflection step length, and controls the MEMS galvanometer a4 to stop scanning. The photodetector a is used to detect the laser signal emitted by the beam splitter a3 and output a bias voltage signal to the control unit a, wherein the photodetector a is a four-quadrant detector a8.

[0044] The signal receiving module includes an optical path unit b, a control unit b, and a four-quadrant detector b9, wherein the optical path unit b includes a MEMS galvanometer b5, a beam splitter b6, and a corner reflector 7 from front to back. The optical path unit b is used to receive the laser signal emitted by the laser 1 of the signal transmitting module. The initial installation positions of the optical path unit b of the signal receiving module and the four-quadrant detector b9 should meet the requirement that the optical path unit b of the signal receiving module can align the laser signal emitted by the signal transmitting module to the center of the four-quadrant detector b9. The corner reflector 7 reflects a part of the laser signal back to the optical path unit a through the beam splitter b6 and the MEMS galvanometer b5 in sequence, so as to achieve simultaneous alignment of both ends, and realize secondary uncertain range scanning through the MEMS galvanometer b5. When the control unit b does not receive the laser signal, it controls the MEMS galvanometer b6 to realize secondary uncertain range scanning. When the control unit b receives the bias voltage signal, it calculates the bias voltage signal to obtain the spot position information and the galvanometer offset step length, and controls the MEMS galvanometer b6 to complete the alignment and tracking of the laser spot. The photodetector b is used to detect the laser signal emitted by the beam splitter b6 and output a bias voltage signal to the control unit b, wherein the photodetector b is a four-quadrant detector b9.

[0045] Furthermore, the optical path unit a and the optical path unit b together form a coaxial optical path.

[0046] Furthermore, in the optical path unit a: the laser 1 is used to receive a laser trigger signal and emit a laser beam; the beam expander 2 is used to change the diameter and divergence angle of the laser beam; the beam splitter a3 is used to split the laser beam; and the MEMS galvanometer a is used to control the laser signal for capture, alignment and tracking.

[0047] Furthermore, in the optical path unit b: the corner reflector 7 is used to control the laser beam to return from the signal receiving module to the signal transmitting module along the coaxial optical path; the beam splitter b6 is used to split the laser beam; and the MEMS galvanometer b5 is used to control the laser signal to capture, align and track.

[0048] Furthermore, the control unit a in the signal transmitting module has the same structure and layout as the control unit b in the signal receiving module, and both include a galvanometer control module, a DAC control module, a data processing module, an MCU microcontroller, and an ADC control module connected in sequence. Specifically:

[0049] The control unit a in the signal transmission module includes a galvanometer control module a14, a DAC control module a13, a data processing module a12, an MCU single chip a11, and an ADC control module a10, wherein the ADC control module a10 is connected to the four-quadrant detector a8, and the galvanometer control module a14 is connected to the MEMS galvanometer a4. Specifically:

[0050] The ADC control module a10 is used to convert the three analog signals transmitted by the four-quadrant detector a8 into digital signals; the MCU single-chip computer a11 is used to output a trigger signal to the laser 1, and at the same time to calculate the position of the laser spot according to the received bias voltage signal, and calculate the galvanometer deflection step length; the data processing module a12 is used to filter the collected digital signals; the DAC control module a10 is used to output two positive and negative analog voltages to the galvanometer control module a14; the galvanometer control module a14 is used to drive the MEMS galvanometer a4 to move.

[0051] The control unit b in the signal receiving module includes a galvanometer control module b19, a DAC control module b18, a data processing module b17, an MCU single chip microcomputer b16, and an ADC control module b15 which are connected in sequence, wherein the ADC control module b15 is connected to the four-quadrant detector b9, and the galvanometer control module b19 is connected to the MEMS galvanometer b5. Specifically:

[0052] The ADC control module b15 is used to convert the three analog signals transmitted by the four-quadrant detector b9 into digital signals; the MCU single-chip computer b16 is used to calculate the position of the laser spot according to the received bias voltage signal, and calculate the galvanometer deflection step; the data processing module b17 is used to filter the collected digital signals; the DAC control module b18 is used to output two positive and negative analog voltages to the galvanometer control module b19; the galvanometer control module b19 is used to drive the MEMS galvanometer b5 to move.

[0053] A laser double-end blind alignment method for dynamic target communication is implemented based on a laser double-end blind alignment device. A signal transmitting module controls a MEMS galvanometer a4 to scan within a primary uncertainty range by detecting a laser signal returned by a signal receiving module. The primary uncertainty range is the range of the position of the signal receiving module relative to the signal transmitting module. The signal receiving module controls a MEMS galvanometer b5 to scan within a secondary uncertainty range by detecting a laser signal emitted by the transmitting module. The secondary uncertainty range is the range of the laser signal that can be reflected back by the signal receiving module. When the signal receiving module captures the laser signal, the laser signal is further aligned and tracked. The specific steps are as follows: Figure 3 As shown:

[0054] S1, first initialize the four-quadrant detector a8 and the four-quadrant detector b9, set the threshold voltage for the voltage value output by the four-quadrant detector a8 and the four-quadrant detector b9, and then continue to initialize the MEMS galvanometer a4 and the MEMS galvanometer b5. After the initialization is completed, the MCU single-chip microcomputer a11 controls the laser 1 to emit a laser signal through the trigger signal, and the laser signal is emitted to the terminal through the beam expander 2, the beam splitter a3, and the MEMS galvanometer a4;

[0055] S2, determine whether the four-quadrant detector a8 detects the laser signal reflected by the corner reflector 7. If no laser signal is detected, the MCU single-chip computer a11 controls the MEMS galvanometer a4 to perform spiral scanning in the first-level uncertainty range according to the minimum step length of the MEMS galvanometer a4 until the four-quadrant detector a8 detects the laser signal. After the MCU single-chip computer a11 receives the bias voltage signal output by the four-quadrant detector a, it controls the MEMS galvanometer a4 to stop scanning. The first-level uncertainty range scanning ends;

[0056] S3, after the first level of uncertain range scanning is completed, the laser signal enters the signal receiving module, and the laser signal passes through the MEMS galvanometer b5 and then reaches the beam splitter b5. The laser signal of the beam splitter b5 is divided into two beams, one beam enters the corner reflector 7, and the other beam enters the direction of the four-quadrant detector b9;

[0057] S4, determines whether the four-quadrant detector b9 detects the incident laser signal. If no laser signal is detected, the MCU single-chip computer b16 controls the MEMS galvanometer b5 to perform spiral scanning within the secondary uncertainty range according to the minimum step length of the MEMS galvanometer b5 until the four-quadrant detector b9 detects the laser signal. The data processing module b17 performs Kalman filtering on the bias voltage signal output by the four-quadrant detector b9 and sends it to the MCU single-chip computer b16. The MCU single-chip computer b16 calculates the laser spot position information and the galvanometer deflection step length, and controls the MEMS galvanometer b5 to move the laser spot to the center of the four-quadrant detector b9 and perform continuous tracking and alignment.

[0058] The MCU b16 calculates the laser spot position information, and the specific process is as follows:

[0059]

[0060] Among them, x is the offset distance of the laser spot center in the x direction relative to the center of the four-quadrant detector b9 、 б y is the offset distance of the center of the laser spot in the y direction relative to the center of the four-quadrant detector b9, X is the bias voltage signal output by the four-quadrant detector b9 in the x direction, Y is the bias voltage signal output by the four-quadrant detector b9 in the y direction, and T is the bias voltage signal output by the four-quadrant detector b9 on the entire surface of the four-quadrant detector b9. All three are output by the ADC control module b15; the ADC control module b15 sends the bias voltage signal to the chip of the MCU microcontroller b16 through SPI, and the data processing module b17 filters the input bias voltage signal.

[0061] like Figure 5 The MCU b16 calculates the deflection step length of the galvanometer according to the obtained bias voltage signal, and controls the MEMS galvanometer b5 to capture, align and track the laser signal. The specific process is as follows:

[0062]

[0063] Wherein, d is the distance from the center of the light spot to the center of the four-quadrant detector b9, D is the distance from the MEMS galvanometer b5 to the optical four-quadrant detector b9, θ is the incident angle of the laser to the MEMS galvanometer b5, V represents the maximum output voltage of the DAC control module b18, and α is the maximum polarization angle of the MEMS galvanometer b5. The DAC control module b18 is used to output two positive and negative analog voltages to the galvanometer control module b19 to control the movement of the MEMS galvanometer b5; the DAC control module b18 includes a chip and a reference voltage circuit; the galvanometer control module b19 includes a chip and a reference voltage circuit; the MCU single chip microcomputer b16 sends a bias voltage signal to the chip of the DAC control module b18 through SPI, and then the DAC control module b18 outputs an analog voltage to the galvanometer control module b19 to control the movement of the galvanometer.

[0064] In this embodiment, the MEMS galvanometer a is controlled by the MCU single chip a to perform a primary range scan on the uncertain area in a spiral scanning manner, and the MEMS galvanometer b is controlled by the MCU single chip b to perform a secondary range scan on the uncertain area in a spiral scanning manner. The secondary scanning range is smaller than the primary scanning range. Figure 4 As shown, rapid capture of laser signals is achieved.

[0065] like Figure 6 As shown, Figure 6 (a) is a comparison between the capture efficiency of the scanning method of the present invention and the traditional capture efficiency. The scanning method of the present invention has a higher capture efficiency; Figure 6 (b) is a schematic diagram of the effect of the communication receiving end tracking the laser spot when the communication transmitting end and the communication receiving end move at the same time. The tracking offset is used to evaluate the tracking effect. The spot always remains at the center position of the four-quadrant detector. The tracking offset is within 0.025mm, which has a higher aiming accuracy in existing technical research.

[0066] The present invention aims to solve the problem of low capture efficiency caused by the dynamic movement of the laser transceiver in the existing capture technology. The laser signal is reflected back to the laser transmitting end by a corner reflector, and the galvanometer is controlled to perform a first-level uncertain range scan according to the reflected laser signal, and then a second-level uncertain range scan is performed after the range is narrowed, thereby improving the capture efficiency of the laser signal. The problem of long time caused by blind scanning over a large range is avoided, which is of great significance to improving the stability of wireless optical communication.

[0067] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A laser double-end blind alignment device for dynamic target communication, characterized in that: The laser double-end blind alignment device comprises a signal transmitting module and a signal receiving module; The signal transmission module comprises an optical path unit a, a control unit a, and a four-quadrant detector a (8), wherein the optical path unit a comprises, from front to back, a laser (1), a beam expander (2), a beam splitter a (3), and a MEMS galvanometer a (4); the laser (1) is used to receive a laser trigger signal and emit a laser beam; after the laser (1) emits a laser signal, the optical path unit a adjusts the shape and emission direction of the laser beam through the beam expander (2) and the beam splitter a (3) and then emits the laser signal to a target communication area, and is also used to receive the laser beam reflected back by the signal receiving module; the MEMS galvanometer a (4) is used to control the laser signal to capture, align and track, and realize a first-level uncertain range scanning through the MEMS galvanometer a (4); the four-quadrant detector a (8) is used to detect the laser signal emitted by the beam splitter a (3), and output a bias voltage signal to the control unit a; The signal receiving module comprises an optical path unit b, a control unit b, and a four-quadrant detector b (9), wherein the optical path unit b comprises a MEMS galvanometer b (5), a beam splitter b (6), and a corner reflector (7) in order from front to back; the optical path unit b is used to receive a laser signal emitted by a laser (1) of a signal transmitting module; the MEMS galvanometer b (5) is used to control the laser signal for capturing, aligning, and tracking; the corner reflector (7) reflects a portion of the laser signal back to the optical path unit a through the beam splitter b (6) and the MEMS galvanometer b (5) in order, thereby realizing dual-end simultaneous alignment, and realizing secondary uncertain range scanning through the MEMS galvanometer b (5); the four-quadrant detector b (9) is used to detect the laser signal emitted by the beam splitter b (6), and output a bias voltage signal to the control unit b.

2. According to claim 1, a laser double-end blind alignment device for dynamic target communication is characterized in that: The initial installation positions of the optical path unit a and the four-quadrant detector a (8) in the signal transmission module meet the requirement that the optical path unit a of the signal transmission module can align the laser signal reflected back by the corner reflector (7) with the center of the four-quadrant detector a (8); when the control unit a does not receive the optical laser signal, it controls the MEMS galvanometer a (4) to implement a first-level uncertain range scanning; when the control unit a receives the bias voltage signal, it calculates the bias voltage signal to obtain the light spot position information and the galvanometer deflection step length, and controls the MEMS galvanometer a (4) to stop scanning; The initial installation positions of the optical path unit b of the signal receiving module and the four-quadrant detector b (9) should meet the requirement that the optical path unit b of the signal receiving module can align the laser signal emitted by the signal emitting module with the center of the four-quadrant detector b (9); when the control unit b does not receive the laser signal, it controls the MEMS galvanometer b (6) to realize secondary uncertain range scanning; when the control unit b receives the bias voltage signal, it calculates the bias voltage signal to obtain the light spot position information and the galvanometer offset step length, and controls the MEMS galvanometer b (6) to complete the alignment and tracking of the laser spot.

3. A laser double-end blind alignment device for dynamic target communication according to claim 1, characterized in that: The optical path unit a and the optical path unit b together form a coaxial optical path; the corner reflector (7) is used to control the laser beam to return from the signal receiving module to the signal transmitting module along the coaxial optical path.

4. A laser double-end blind alignment device for dynamic target communication according to claim 1, characterized in that: The control unit a in the signal transmitting module has the same structure and layout as the control unit b in the signal receiving module, and both include a galvanometer control module, a DAC control module, a data processing module, an MCU single chip computer, and an ADC control module which are connected in sequence.

5. A laser double-end blind alignment device for dynamic target communication according to claim 4, characterized in that: The control unit a in the signal transmission module comprises a galvanometer control module a (14), a DAC control module a (13), a data processing module a (12), an MCU single chip computer a (11), and an ADC control module a (10), wherein the ADC control module a (10) is connected to a four-quadrant detector a (8), and the galvanometer control module a (14) is connected to a MEMS galvanometer a (4); specifically: The ADC control module a (10) is used to convert three analog signals transmitted by the four-quadrant detector a (8) into digital signals; the MCU single chip computer a (11) is used to output a trigger signal to the laser (1), and is also used to calculate the position of the laser spot according to the received bias voltage signal, and calculate the deflection step length of the galvanometer; the data processing module a (12) is used to filter the collected digital signals; the DAC control module a (13) is used to output two positive and negative analog voltages to the galvanometer control module a (14); the galvanometer control module a (14) is used to drive the MEMS galvanometer a (4) to move.

6. A laser double-end blind alignment device for dynamic target communication according to claim 4, characterized in that: The control unit b in the signal receiving module comprises a galvanometer control module b (19), a DAC control module b (18), a data processing module b (17), an MCU single chip computer b (16), and an ADC control module b (15) which are connected in sequence, wherein the ADC control module b (15) is connected to the four-quadrant detector b (9), and the galvanometer control module b19 is connected to the MEMS galvanometer b (5); specifically: The ADC control module b (15) is used to convert the three-channel analog signals transmitted by the four-quadrant detector b (9) into digital signals; the MCU single chip microcomputer b16 is used to calculate the position of the laser spot according to the received bias voltage signal, and calculate the deflection step length of the galvanometer; the data processing module b (17) is used to filter the collected digital signals; The DAC control module b (18) is used to output two positive and negative analog voltages to the galvanometer control module b (19); the galvanometer control module b (19) is used to drive the MEMS galvanometer b (5) to move.

7. A laser double-end blind alignment method for dynamic target communication, characterized in that: The laser double-end blind alignment device described in any one of claims 1 to 6 is used for implementation. The laser double-end blind alignment method is as follows: the signal transmitting module controls the MEMS galvanometer a (4) to scan within a primary uncertainty range by detecting the laser signal returned by the signal receiving module. The primary uncertainty range is the range of the position of the signal receiving module relative to the signal transmitting module. The signal receiving module scans within a secondary uncertainty range by detecting the laser signal emitted by the transmitting module. The secondary uncertainty range is the range of the laser signal that can be reflected back by the signal receiving module. When the signal receiving module captures the laser signal, the laser signal is further aligned and tracked.

8. A laser double-end blind alignment method for dynamic target communication according to claim 7, characterized in that: The laser double-end blind alignment method comprises the following steps: S1, firstly initialize the four-quadrant detector a (8) and the four-quadrant detector b (9), and set the threshold voltage for the voltage value output by the four-quadrant detector a (8) and the four-quadrant detector b (9); then continue to initialize the MEMS galvanometer a (4) and the MEMS galvanometer b (5); after the initialization is completed, the MCU single chip computer a (11) controls the laser (1) to emit a laser signal through a trigger signal, and the laser signal is emitted to the terminal through the beam expander (2), the beam splitter a (3), and the MEMS galvanometer a (4); S2, determining whether the four-quadrant detector a (8) detects the laser signal reflected by the corner reflector (7); if no laser signal is detected, the MCU single-chip computer a (11) controls the MEMS galvanometer a4 to perform spiral scanning within the first-level uncertainty range according to the minimum step length of the MEMS galvanometer a (4) until the four-quadrant detector a (8) detects the laser signal; after receiving the bias voltage signal output by the four-quadrant detector a (8), the MCU single-chip computer a (11) controls the MEMS galvanometer a (4) to stop scanning; the first-level uncertainty range scanning is completed; S3, after the first level of uncertain range scanning is completed, the laser signal enters the signal receiving module, and the laser signal passes through the MEMS galvanometer b (5) and then reaches the beam splitter b5. The beam splitter b5 splits the laser signal into two beams, one beam enters the corner reflector (7), and the other beam enters the direction of the four-quadrant detector b (9); S4, determining whether the four-quadrant detector b (9) detects an incident laser signal. If no laser signal is detected, the MCU single chip computer b (16) controls the MEMS galvanometer b (5) to perform spiral scanning within the secondary uncertainty range according to the minimum step length of the MEMS galvanometer b (5) until the four-quadrant detector b (9) detects a laser signal. The data processing module b (17) performs Kalman filtering on the bias voltage signal output by the four-quadrant detector b (9) and sends it to the MCU single chip computer b (16). The MCU single chip computer b (16) calculates the laser spot position information and the galvanometer deflection step length, and controls the MEMS galvanometer b (5) to move the laser spot to the center of the four-quadrant detector b (9) and performs continuous tracking and alignment.

9. A laser double-end blind alignment method for dynamic target communication according to claim 8, characterized in that: In S4, the MCU b (16) calculates the laser spot position information, and the specific process is as follows: Among them, x is the offset distance of the laser spot center in the x direction relative to the center of the four-quadrant detector b (9); y is the offset distance of the center of the laser spot in the y direction relative to the center of the four-quadrant detector b (9); X is the bias voltage signal output by the four-quadrant detector b (9) in the x direction; Y is the bias voltage signal output by the four-quadrant detector b (9) in the y direction; T is the bias voltage signal output by the four-quadrant detector b (9) on the surface of the entire four-quadrant detector b (9); all three are output by the ADC control module b (15), and the ADC control module b (15) sends the bias voltage signal to the chip of the MCU single-chip computer b (16) through SPI, and the input bias voltage signal is filtered by the data processing module b (17); The MCU single chip computer b (16) calculates the deflection step length of the galvanometer according to the obtained bias voltage signal, and controls the MEMS galvanometer b (5) to capture, align and track the laser signal.

10. A laser double-end blind alignment method for dynamic target communication according to claim 9, characterized in that: The MCU single chip microcomputer b (16) controls the MEMS galvanometer b (5) to capture, align and track the laser signal. The specific process is as follows: Wherein, d is the distance from the center of the light spot to the center of the four-quadrant detector b(9), D is the distance from the MEMS galvanometer b(5) to the optical four-quadrant detector b(9), θ is the incident angle of the laser to the MEMS galvanometer b(5), V represents the maximum output voltage of the DAC control module b(18), and α is the maximum polarization angle of the MEMS galvanometer b(5); The DAC control module b (18) comprises a chip and a reference voltage circuit; the galvanometer control module b (19) comprises a chip and a reference voltage circuit; the DAC control module b (18) is used to output two positive and negative analog voltages to the galvanometer control module b (19) to control the movement of the MEMS galvanometer b (5); the MCU single chip computer b (16) sends a bias voltage signal to the chip of the DAC control module b (18) through SPI, and then the DAC control module b (18) outputs an analog voltage to the galvanometer control module b (19) to control the movement of the galvanometer.

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