Miniaturized intelligent cooperative control airborne laser communication terminal and application method thereof

Abstract

The invention discloses a miniaturized intelligent cooperative control airborne laser communication terminal, and the terminal comprises a coarse aiming unit which comprises a universal rotary table and is used for achieving the large-angle range coarse positioning and posture adjustment of the laser communication terminal, and providing a basic positioning reference for the subsequent fine aiming adjustment; the fine sighting unit is driven by piezoelectricity-electromagnetism in a hybrid mode, is matched with the coarse sighting unit, obtains positioning information of the coarse sighting unit and is used for achieving small-angle high-precision correction and compensating for positioning errors of the coarse sighting unit; the intelligent control unit is respectively connected with the coarse aiming unit and the fine aiming unit, and is used for receiving an external control instruction and scanning information fed back by the coarse aiming unit and the fine aiming unit, and generating and outputting a corresponding driving control signal; the invention further discloses an application method of the airborne laser communication terminal. The direct-driven coarse aiming unit is adopted to improve the coarse aiming efficiency, the fine aiming performance is considered through piezoelectric-electromagnetic hybrid driving, platform vibration from low frequency to high frequency can be comprehensively compensated, and the tracking precision and the link stability are improved.

Description

Technical Field

[0001] This invention relates to the field of laser communication technology, and in particular to a miniaturized intelligent collaborative control airborne laser communication terminal and its application method. Background Technology

[0002] Laser communication terminals typically include a coarse aiming unit and a fine aiming unit. The coarse aiming unit (usually a universal turntable) is responsible for scanning and capturing in a large area of ​​uncertainty and guiding the beam to the target direction initially. The fine aiming unit (usually an FSM) is responsible for compensating for residual errors and high-frequency disturbances to achieve high-precision and stable tracking. The advance aiming function is usually an independent module that performs open-loop or simple closed-loop prediction calculations based on navigation information.

[0003] In existing laser communication terminals, the coarse aiming unit suffers from low scanning positioning accuracy and slow speed due to inherent backlash, friction, and elastic deformation in the gear transmission. Its complex and bulky mechanical structure also hinders rapid acquisition and platform attitude control. While the electromagnetic FSM in the fine aiming unit has a large stroke, its low bandwidth and relatively poor accuracy limit the system's ability to handle complex disturbances. Furthermore, existing methods lack sufficient analysis of the dynamic characteristics of the coupled errors at both ends, and lack effective cooperative control algorithms to suppress performance oscillations caused by time delays, resulting in ambiguous system stability boundaries.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The present invention aims to address the shortcomings of the above-mentioned technologies by providing a miniaturized intelligent collaborative control airborne laser communication terminal and its application method, which can perform rapid and accurate scanning and acquisition, high-bandwidth and high-precision vibration suppression, and stable and reliable bidirectional tracking, while meeting the requirements of lightweight and intelligent systems.

[0006] The technical solution provided by this invention is as follows:

[0007] On one hand, this invention discloses a miniaturized airborne laser communication terminal with intelligent collaborative control, comprising:

[0008] The coarse aiming unit, including the universal turntable, is used to achieve coarse positioning and attitude adjustment of the laser communication terminal over a large angle range, providing a basic positioning reference for subsequent fine aiming adjustments.

[0009] The fine aiming unit, driven by a piezoelectric-electromagnetic hybrid system, works in conjunction with the coarse aiming unit to acquire the positioning information from the coarse aiming unit. This information is used to achieve high-precision small-angle correction based on the coarse positioning, compensating for the positioning error of the coarse aiming unit.

[0010] The intelligent control unit is electrically or signal-connected to the coarse aiming unit and the fine aiming unit, respectively, and is used to receive external control commands and scanning information fed back by the coarse aiming unit and the fine aiming unit, and generate and output corresponding drive control signals.

[0011] Furthermore, the airborne laser communication terminal also includes a two-way cooperative tracking algorithm module, which is integrated into the intelligent control unit. This module is used to construct a coarse-fine cooperative control model based on the feedback data from the coarse aiming unit and the fine aiming unit, and dynamically coordinate the working timing and control parameters of the coarse aiming unit and the fine aiming unit to achieve cooperative tracking between the two.

[0012] Furthermore, the universal turntable is connected to a hollow brushless DC torque motor, which is fixedly connected to the rotation axis of the universal turntable. This motor is used to directly drive the universal turntable to drive the laser communication transmitting / receiving module to achieve coarse angle adjustment in two dimensions.

[0013] Furthermore, the precision aiming unit includes an electromagnetic drive module and a piezoelectric drive module. The electromagnetic drive module and the piezoelectric drive module are connected in parallel or in series and drive the same fast-turning mirror in a hybrid manner. The electromagnetic drive module is used to achieve medium-precision, medium-stroke attitude adjustment, while the piezoelectric drive module is used to achieve high-precision, micro-stroke attitude compensation.

[0014] The intelligent control unit drives the electromagnetic drive module and / or piezoelectric drive module to work based on the positioning error.

[0015] On the other hand, the present invention also discloses an application method for a miniaturized intelligent collaborative control airborne laser communication terminal, applicable to any of the above-mentioned airborne laser communication terminals, comprising:

[0016] S10. Initialize the parameters of the coarse aiming unit and the fine aiming unit, and set the initial state information;

[0017] Obtain the offset vectors corresponding to the initial line-of-sight direction and aiming angle;

[0018] S20. The coarse aiming unit enters the scanning mode and dynamically selects the optimal scanning strategy to scan based on the uncertainty range and the characteristics of the beacon light, so as to balance scanning efficiency and acquisition reliability.

[0019] S30. Based on adaptive signal decision, after the scan is completed, the entire field of view data is analyzed to determine the optimal capture point and improve the capture success rate.

[0020] S40. After step S30 is completed, the precision aiming unit is started, and the piezoelectric driver and electromagnetic driver drive the fast steering mirror to work in combination, and work with the intelligent control unit to achieve high-speed closed-loop feedback control.

[0021] The intelligent control unit continuously receives the motion status of the other units, obtains the advance aiming angle in real time, and drives the advance aiming scope to perform compensation; at the same time, in the two-way communication mode, the intelligent control unit runs a two-way cooperative tracking algorithm to perform two-way cooperative control.

[0022] In narrow beacon acquisition mode, the S50 reduces uncertainty angles through high-precision inter-satellite / satellite-to-ground calibration and performs rapid scans over small areas by utilizing the large travel capability of the precision-aiming FSM, thus completing scan optimization.

[0023] Furthermore, the initial state information includes position, velocity, and attitude;

[0024] Obtaining the initial line-of-sight direction includes calculating the initial line-of-sight direction unit vector, where the formula for calculating the initial line-of-sight direction includes:

[0025]

[0026] Where R t Let R be the initial position vector of this end. r The initial position vector of the target end;

[0027] Obtaining the offset vector corresponding to the aiming angle includes calculating the unit vector of the advance aiming direction, wherein the formula for calculating the unit vector of the advance aiming direction includes:

[0028]

[0029] Where V rel =V r -V t V r and V t Let be the velocity vectors of the target end and the local end, respectively; τ is the estimated time required for the signal to propagate from the local end to the target end, where τ is calculated using the following formula:

[0030]

[0031] Where the speed of light is c, Rt is the initial position vector of this end, and Rr is the initial position vector of the target end.

[0032] Furthermore, the control core is based on Obtain the required azimuth and pitch angle commands for the omnidirectional turntable, and instruct the omnidirectional turntable to move to the predicted direction.

[0033] Furthermore, the optimal scanning strategy in step S20 includes:

[0034] S201, The intelligent control unit captures the angular radius ρ within an uncertain range. ROU and the divergence angle θ of the beacon light used beam ;

[0035] S202, if ρ ROU If a small and uncertain region can be approximated as a circle, it is classified as a "small-scale concentrated uncertainty" scenario. In this case, a spiral scan is selected. The spiral scan formula includes:

[0036]

[0037] Where r(t) = r0 + Δr·t is the scanning radius, which increases linearly with time;

[0038] If ρ ROU If a large and uncertain area has an irregular shape, it is determined to be a scene of "large-scale or regular area with uncertain shape", and raster scanning is selected in this case;

[0039] S203. Set the scan step angle ∆s. The setting of the scan step angle ∆s shall satisfy... Where η is a coverage coefficient less than 1, typically taken as 0.5 to 0.8;

[0040] Meanwhile, the high-sensitivity area array detector continuously collects optical signals.

[0041] Furthermore, the control output formula of the electromagnetic driver hybrid drive and PID control interface in step S40 includes:

[0042]

[0043] Where e(t) is the tracking error at the current moment, and K is the input signal of the controller; p k i k d These are the proportional, integral, and derivative gain coefficients, which are pre-calibrated by the system or set by an adaptive algorithm, and determine the dynamic response characteristics of the controller; U(t) is the total control quantity calculated by the controller to drive the fast steering mirror.

[0044] Furthermore, bidirectional cooperative tracking algorithms include:

[0045] Based on the bidirectional tracking error coupling model, the aiming error state of the peer end and its impact on the received optical power of the local end are estimated in real time. The tracking loop parameters of the local end are dynamically adjusted, thereby suppressing the performance fluctuations caused by transmission delay and ensuring the common stability of the bidirectional link.

[0046] This invention provides a miniaturized intelligent collaborative control airborne laser communication terminal and its application method, which, compared with the prior art, has the following beneficial technical effects:

[0047] The coarse aiming unit uses a direct-drive universal turntable to eliminate transmission errors and respond faster. Combined with an intelligent scanning strategy and an adaptive decision algorithm, it significantly shortens the acquisition time and improves the acquisition probability, making it particularly suitable for harsh scenarios such as narrow beacons. The fast-turning mirror has high bandwidth and long stroke, which can fully compensate for platform vibrations from low frequency to high frequency.

[0048] Initial alignment is completed by the coarse aiming unit. After coarse aiming and acquisition, the fine aiming unit fully utilizes the advantages of hybrid drive. The piezoelectric actuator cancels the high-frequency micro-jitter of the rotor and engine at an extremely high frequency (>1kHz), and the electromagnetic actuator compensates for the low-frequency changes in the airframe attitude.

[0049] With the cooperation of coarse aiming unit and fine aiming unit, a stable and reliable laser link can still be achieved in a strong vibration environment. The tracking error variance is reduced by more than 50% compared with a single-drive FSM system.

[0050] The bidirectional cooperative tracking algorithm effectively suppresses the instability risk caused by the mutual coupling of vibrations at both ends, improves the robustness of the link at the system level, and effectively suppresses the impact of error mutual coupling and transmission delay.

[0051] The simplified structure of airborne laser communication terminals (such as direct drive and possible optical path multiplexing) can reduce weight, size and power consumption, while improving performance and meeting the stringent requirements of future space-based and airborne platforms for payloads. Attached Figure Description

[0052] Figure 1 This is a flowchart of the application method of the airborne laser communication terminal in this invention. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0054] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0055] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0056] As attached Figure 1 This invention provides a miniaturized, intelligent, collaboratively controlled airborne laser communication terminal, comprising:

[0057] The coarse aiming unit, including the universal turntable, is used to achieve coarse positioning and attitude adjustment of the laser communication terminal over a large angle range, providing a basic positioning reference for subsequent fine aiming adjustments.

[0058] The fine aiming unit, driven by a piezoelectric-electromagnetic hybrid system, works in conjunction with the coarse aiming unit to acquire the positioning information from the coarse aiming unit. This information is used to achieve high-precision small-angle correction based on the coarse positioning, compensating for the positioning error of the coarse aiming unit.

[0059] The intelligent control unit is electrically or signal-connected to the coarse aiming unit and the fine aiming unit, respectively, and is used to receive external control commands and scanning information fed back by the coarse aiming unit and the fine aiming unit, and generate and output corresponding drive control signals.

[0060] Obviously, the coarse aiming unit achieves large-angle coarse positioning through a universal turntable, laying the benchmark for subsequent fine aiming and solving the problem of difficult large-field-of-view acquisition in traditional airborne laser communication terminals; the fine aiming unit adopts piezoelectric-electromagnetic hybrid drive, achieving small-angle high-precision correction on the basis of coarse positioning, accurately compensating for coarse aiming errors, and solving the problem that large angle and high precision cannot be achieved simultaneously in a single drive method.

[0061] The intelligent control unit uniformly interfaces with the coarse aiming unit and the fine aiming unit to realize closed-loop processing of external command reception and unit feedback information, ensuring the continuity of terminal positioning and adjustment actions, adapting to the working conditions of airborne scenarios where the terminal attitude is easily affected by flight disturbances, and improving the stability of terminal operation.

[0062] In some embodiments, the airborne laser communication terminal further includes a bidirectional collaborative tracking algorithm module. The algorithm module is integrated into the intelligent control unit and is used to construct a coarse-fine collaborative control model based on the feedback data from the coarse aiming unit and the fine aiming unit, dynamically coordinate the working timing and control parameters of the coarse aiming unit and the fine aiming unit, and realize their collaborative tracking.

[0063] The bidirectional collaborative tracking algorithm module is integrated into the intelligent control unit. Based on the feedback data from the coarse aiming unit and the fine aiming unit, a dedicated collaborative control model is constructed. This breaks through the limitations of the existing technology where the coarse aiming unit and the fine aiming unit work independently and their timing is disconnected, and achieves dynamic coordination of their working timing and control parameters.

[0064] In the two-way collaborative tracking mode, the positioning reference of the coarse aiming unit and the error compensation of the fine aiming unit complement each other, avoiding excessive coarse aiming error that could lead to fine aiming overload, and also avoiding frequent fine aiming adjustments that could affect the stability of coarse aiming. This significantly improves the overall aiming accuracy and response speed of the terminal, and meets the needs of high-speed airborne laser communication.

[0065] In some embodiments, the universal turntable is connected to a hollow brushless DC torque motor, which is fixedly connected to the rotation axis of the universal turntable and is used to directly drive the universal turntable to drive the laser communication transmitting / receiving module to achieve coarse angle adjustment in two-dimensional direction.

[0066] As is easy to understand, the hollow brushless DC torque motor is fixedly connected to the rotating shaft to achieve direct drive. Compared with the traditional indirect drive method, it reduces transmission backlash and energy loss, and improves the response speed and positioning consistency of the two-dimensional coarse angle adjustment of the universal turntable.

[0067] Alternatively, in addition to the hollow brushless torque motor in the above embodiment, other direct drive methods, such as magnetic levitation direct drive motors, can also be used, with the goal of eliminating transmission chain errors.

[0068] The coarse aiming detector can be any of the following: a four-quadrant detector (QD), a CCD, or a CMOS array.

[0069] In some embodiments, the precision aiming unit includes an electromagnetic drive module and a piezoelectric drive module, which are connected in parallel or in series and drive the same fast-turning mirror in a hybrid manner; the electromagnetic drive module is used to achieve medium-precision, medium-stroke attitude adjustment, and the piezoelectric drive module is used to achieve high-precision, micro-stroke attitude compensation.

[0070] The intelligent control unit drives the electromagnetic drive module and / or piezoelectric drive module to work based on the positioning error.

[0071] The aforementioned precision aiming unit explicitly uses a hybrid drive system for the same fast-turning mirror, achieving hierarchical drive and complementary advantages to address the issue of insufficient accuracy in electromagnetic drive. The intelligent control unit can flexibly drive a single module or two modules working collaboratively based on the positioning error, adapting to different error levels as needed (large error → electromagnetic drive as the primary method, small error → piezoelectric drive as the primary method, medium error → dual-module collaboration), balancing the efficiency and accuracy of precision aiming adjustments while reducing drive energy consumption. The hybrid drive architecture adapts to the dynamic operating conditions of airborne laser communication terminals, enabling rapid response to attitude disturbances during flight, ensuring aiming stability, and improving the anti-interference capability of the communication link.

[0072] In some embodiments, the intelligent control unit includes:

[0073] The signal acquisition module is used to acquire the angular displacement signal of the coarse aiming unit, the displacement feedback signal of the fine aiming unit, and the light intensity detection signal of the laser communication link;

[0074] The data processing module is used to filter, amplify, and digitally process the acquired signals to extract positioning error information;

[0075] The control command generation module generates drive control commands adapted to the coarse aiming unit and the fine aiming unit based on the cooperative control instructions output by the bidirectional cooperative tracking algorithm module and the error information extracted by the data processing module.

[0076] The control command output module converts the drive control commands generated by the control command generation module into drive current or drive voltage signals for the corresponding unit.

[0077] In this application, the signal acquisition module takes into account the angular displacement signal of the coarse aiming unit, the displacement feedback signal of the fine aiming unit, and the light intensity detection signal of the laser communication link. The acquisition dimensions are comprehensive, providing complete data support for subsequent errors and avoiding control deviations caused by signal loss. The data processing module optimizes signal quality through filtering, amplification, and digital processing, eliminates interference signals in the airborne environment, and improves the accuracy of positioning error extraction.

[0078] The control command generation module combines a two-way collaborative tracking algorithm with error information to generate targeted drive commands for coarse and fine aiming units, achieving "on-demand driving". The control command output module adapts to the unit drive requirements (current / voltage signals) without the need for additional conversion components, improving the response efficiency of control commands and further ensuring the real-time performance of terminal aiming.

[0079] This invention also provides an application method for a miniaturized intelligent collaborative control airborne laser communication terminal, wherein the airborne laser communication terminal applying any of the above includes:

[0080] S10. Initialize the parameters of the coarse aiming unit and the fine aiming unit, and set the initial state information;

[0081] Obtain the offset vectors corresponding to the initial line-of-sight direction and aiming angle;

[0082] S20. The coarse aiming unit enters the scanning mode and dynamically selects the optimal scanning strategy to scan based on the uncertainty range and the characteristics of the beacon light, so as to balance scanning efficiency and acquisition reliability.

[0083] S30. Based on adaptive signal decision, after the scan is completed, the entire field of view data is analyzed to determine the optimal capture point and improve the capture success rate.

[0084] S40. After step S30 is completed, the precision aiming unit is started, and the piezoelectric driver and electromagnetic driver drive the fast steering mirror to work in combination, and work with the intelligent control unit to achieve high-speed closed-loop feedback control.

[0085] The intelligent control unit continuously receives the motion status of the other units, obtains the advance aiming angle in real time, and drives the advance aiming scope to perform advance aiming compensation; at the same time, in two-way communication mode, the intelligent control unit runs a two-way cooperative tracking algorithm to perform two-way cooperative control.

[0086] In narrow beacon acquisition mode, the S50 reduces uncertainty angles through high-precision inter-satellite / satellite-to-ground calibration and performs rapid scans over small areas by utilizing the large travel capability of the precision-aiming FSM, thus completing scan optimization.

[0087] By adopting a progressive logic of "initialization → coarse scanning → optimal acquisition → fine aiming closed loop → narrow beacon optimization", a complete closed loop is formed from initial calibration to final optimization, which improves the acquisition success rate and enhances the stability of tracking.

[0088] In the coarse aiming stage, the optimal scanning strategy is dynamically selected to balance scanning efficiency and acquisition reliability, adapting to the varying uncertainty range of communication targets in airborne scenarios. In the fine aiming stage, a hybrid drive combined with high-speed closed-loop feedback, along with advance aiming compensation and two-way collaborative control, ensures high-precision tracking. In the narrow beacon mode, scanning optimization is achieved by reducing the uncertainty angle through calibration and performing rapid scanning within a small area during fine aiming, further improving acquisition efficiency and accuracy.

[0089] In some embodiments, the initial state information in step S10 includes position, velocity, and attitude;

[0090] Obtaining the initial line-of-sight direction includes calculating the initial line-of-sight direction unit vector, where the formula for calculating the initial line-of-sight direction unit vector includes:

[0091]

[0092] Where R t Let R be the initial position vector of this end. r The initial position vector of the target end;

[0093] It should be noted that, in order to compensate for the relative motion of the target during the signal propagation time in space, the offset vector corresponding to the advance aiming angle is calculated.

[0094] Obtaining the offset vector corresponding to the aiming angle includes calculating the unit vector of the advance aiming direction, wherein the formula for calculating the unit vector of the advance aiming direction includes:

[0095]

[0096] Where V rel =V r -V t V r and V t These are the velocity vectors at the target end and the local end, respectively. rel Let be the relative velocity vector between the local end and the target end; τ is the estimated time required for the signal to propagate from the local end to the target end, where τ is calculated using the following formula:

[0097]

[0098] Where the speed of light is c, Rt is the initial position vector of this end, and Rr is the initial position vector of the target end.

[0099] Furthermore, the control core is based on Obtain the required azimuth and pitch angle commands for the omnidirectional turntable, and instruct the omnidirectional turntable to move to the predicted direction.

[0100] It should be noted that, considering the existence of an uncertain angle (AOU) in reality, the turntable enters scanning mode; the intelligent control unit dynamically selects the optimal scanning strategy based on the uncertainty range (ROU) and the characteristics of the beacon light.

[0101] Specifically, the optimal scanning strategies include:

[0102] S201, The intelligent control unit captures the angular radius ρ within an uncertain range. ROU and the (full angle) divergence angle θ of the beacon light used beam ;

[0103] S202, if ρ ROU If a small and uncertain region can be approximated as a circle, it is classified as a "small-scale concentrated uncertainty" scenario, in which case a spiral scan is selected; the spiral scan formula includes:

[0104]

[0105] Where r(t) = r0 + Δr·t is the scanning radius, which increases linearly with time;

[0106] The advantage of spiral scanning is that it expands continuously outward from the prediction center point, the scanning path is continuous, it can quickly cover the circular area centered on the initial aiming point, and theoretically there is no repeated path.

[0107] If ρ ROU If a large and uncertain area has an irregular shape, it is determined to be a scene of "large-scale or regular area with uncertain shape", and raster scanning is selected in this case;

[0108] The advantage of raster scanning is that it can systematically and completely cover a regular rectangular area, making it suitable for scenarios with a large ROU or where it is necessary to ensure 100% coverage of the set area.

[0109] S203. Set the scan step angle ∆s. The setting of the scan step angle ∆s shall satisfy... Where η is a coverage coefficient less than 1, usually taken as 0.5~0.8. This range of scanning step angle ∆s can ensure that adjacent scanning spots overlap, avoiding the omission of targets due to scanning gaps; at the same time, the high-sensitivity area array detector continuously collects light signals.

[0110] During the system scanning and target acquisition process described above, the intelligent control unit runs two decision algorithms in parallel: threshold testing and memory comparison. When the signal-to-noise ratio (SNR) is good and known, the fast threshold testing is used first to complete the acquisition. In low SNR or narrow beacon mode, the memory comparison algorithm is activated. After the scan is completed, the entire field of view data is comprehensively analyzed to determine the optimal acquisition point, thereby improving the acquisition success rate.

[0111] In some embodiments, after the precision aiming unit is activated, the piezoelectric-electromagnetic hybrid driven fast steering mirror (FSM) begins operation. The piezoelectric actuator is responsible for compensating for high-frequency micro-vibrations above several hundred hertz, while the electromagnetic actuator is responsible for compensating for low-frequency, wide-range attitude drift and coarse aiming residual errors. The intelligent control unit integrates sub-pixel-level spot position information provided by the precision aiming detector (such as a PSD or high-frame-rate CMOS) to achieve high-speed closed-loop feedback control, ultimately achieving a tracking accuracy better than 1 microradian.

[0112] Furthermore, the control output formula of the electromagnetic driver hybrid drive and PID control interface in step S40 includes:

[0113]

[0114] Where e(t) is the tracking error at the current moment, and K is the input signal of the controller; p k i k dThese are the proportional, integral, and derivative gain coefficients, which are pre-calibrated by the system or set by an adaptive algorithm, and determine the dynamic response characteristics of the controller; U(t) is the total control quantity calculated by the controller to drive the fast steering mirror.

[0115] During the operation of the precision aiming unit, the intelligent control unit does not directly apply the total control quantity U(t) to a single driver. Based on the hybrid drive architecture, the total control quantity U(t) needs to be allocated according to frequency characteristics. Specifically, a high-frequency pass filter is used to extract the high-frequency component U of U(t). h (t) is used to drive a piezoelectric ceramic actuator to compensate for high-frequency micro-vibrations above several hundred hertz; simultaneously, a low-frequency component U of U(t) is extracted through a low-frequency pass filter. l (t) is used to drive the electromagnetic actuator to compensate for low-frequency, wide-range attitude drift and coarse aiming residual error.

[0116] In some embodiments, during the operation of the precision aiming unit in step S40, advance calculation and compensation are performed in real time, as follows:

[0117] The intelligent control unit continuously receives high-precision motion status information from the platform navigation system, including the position vector R. t (t), R r (t), velocity vector V t (t), V r (t), and acceleration vector A t (t), A r (t) (optional).

[0118] To accurately compensate for the target's motion during the dynamically changing propagation delay, the calculation of the high-precision advance aiming angle is an iterative prediction process. Assume a beam planned to be emitted at the current local time t has an estimated arrival time at the target of t' = t + τ(t), where τ(t) is the real-time estimated one-way propagation time of the signal.

[0119] Precise pre-aiming direction, that is, the predicted position of the target at time t' corresponding to the launch time t, and its unit vector. Calculate using the following steps:

[0120] (1) Propagation delay estimation: Initial time t0, τ (0) =‖R r (t)−R t Considering relative motion, a more accurate τ can be obtained by iteratively solving the following equation: (t)‖ / c

[0121]

[0122] Where R r(t+τ (k) This is obtained by extrapolating from the current velocity and acceleration information, iterating to ||τ||. (k+1) −τ (k) The propagation delay estimate τ is obtained when the value is less than the set threshold. ∗ .

[0123] (2) Target location prediction: based on convergent τ ∗ Predict the target's position at the time the signal arrives:

[0124]

[0125] When acceleration information is unreliable or has a negligible impact, it can be simplified to a uniform velocity model. The formula for the uniform velocity model is as follows:

[0126]

[0127] (3) Calculation of advance aiming direction: The high-precision advance aiming direction unit vector required at launch time t is:

[0128]

[0129] Furthermore, when the aforementioned pre-aiming direction calculation model is applied to high-speed scenarios, it is necessary to introduce relativistic kinematic correction terms to further improve accuracy, thus forming the aforementioned relativistic kinematic model. Based on this, the control core converts the pre-aiming direction unit vector into a drive command, controlling the pre-aiming scope (which can be a standalone scope or reused with the precision aiming rapid turning scope) to perform compensation.

[0130] In some embodiments, during the operation of the precision aiming unit in step S40, bidirectional cooperative control is also performed through a bidirectional cooperative tracking algorithm. The bidirectional cooperative tracking algorithm includes: in bidirectional communication mode, the controller runs a bidirectional cooperative tracking algorithm based on a bidirectional tracking error coupling model, which estimates the aiming error state of the peer end and its impact on the received optical power of the local end in real time, and dynamically adjusts the tracking loop parameters (such as gain bandwidth) of the local end, thereby suppressing performance fluctuations caused by transmission delay and ensuring the common stability of the bidirectional link.

[0131] Furthermore, the model content and operating logic of the bidirectional cooperative tracking algorithm are as follows:

[0132] (1) Error-power coupling model:

[0133] For the two communicating parties (denoted as terminal A and terminal B), their tracking errors (e, respectively) A (t) and e B (t) will affect each other's received beacon power through the spatial link. In a well-collimated link, this effect can be modeled as:

[0134]

[0135] in, τ represents the optical power received by terminals A and B at time t, respectively; d Let be the signal transmission delay between the two ends; L be a constant related to the link distance and the optical system; and w be the characteristic radius of the received light spot. This model describes the historical tracking error e at the other end. opp (t−τ d How does this affect the current received power at this end?

[0136] (2) Algorithm execution logic steps:

[0137] Step 1: Information Acquisition and Preprocessing: The controller reads the received optical power P at the local end in real time. rx (t), and receives its own tracking error state estimate, which is timestamped and periodically sent by the peer through the communication link. ;

[0138] Step 2: Online estimation of coupling strength: combining the fluctuation of the received power at this end ΔP rx (t) Error information reported by the other end The actual error-power coupling coefficient K of the current link is estimated online using a coupling model. coup (t);

[0139] Step 3: Estimation and Prediction of Error State at the Other End: When no direct report is received from the other end, the algorithm uses the estimated K... coup (t) and local P rx The change of (t) is used to estimate the opposite end at time t−τ. d Error equivalent value Furthermore, by combining the motion state information of the other end, the potential disturbance Δd it may cause to the local end at the current time t is predicted. ext (t);

[0140] Step 4: Dynamic adjustment of local control parameters: based on the predicted external disturbance Δdext(t) and coupling strength K coup (t), dynamically adjust the control parameters or feedforward compensation terms of the local fine-aiming tracking loop; the principle of dynamic adjustment is: when the coupling is strong and the prediction disturbance is large, appropriately reduce the loop gain to improve stability; when the coupling is weak or the disturbance is small, restore or increase the gain to ensure tracking bandwidth and accuracy.

[0141] It should be noted that the model content and operating logic of the aforementioned bidirectional cooperative tracking algorithm can be optimized in narrow beacon mode. To meet the requirements of system lightweighting, a narrow beacon acquisition mode is supported. In this mode, high-precision inter-satellite / satellite-to-ground calibration reduces the uncertainty angle, and the large stroke capability of the Fast Steering Mirror (FSM) is used to perform a small-range rapid scan, replacing some coarse aiming functions. This optimization process eliminates the need for beacon light with a large divergence angle, simplifies the optical system structure, and reduces system power consumption.

[0142] For example, the airborne laser communication terminal and its application method in this application can be applied to vibration-resistant laser networking among UAV swarms, wherein the parameter settings include:

[0143] Platform: Multiple medium-sized UAVs (with a rich vibration spectrum, 1-500Hz);

[0144] Terminal: Lightweight design with enhanced vibration resistance;

[0145] Precision aiming: Optimize the control algorithm of the fast steering mirror (FSM) for hybrid drive, and use piezoelectric units to cope with high-frequency engine vibration.

[0146] The implementation process includes:

[0147] Dynamic capture: The drone's coarse aiming unit completes the initial alignment with the assistance of GPS / INS. Due to platform vibration, the uncertainty range is large, so the controller selects a scanning pattern with strong anti-interference capabilities.

[0148] High bandwidth stability: After acquisition, the precision aiming unit fully leverages the advantages of hybrid drive. The piezoelectric actuator cancels the high-frequency micro-jitter of the rotor and engine at an extremely high frequency (>1kHz); the electromagnetic actuator compensates for the low-frequency changes in the airframe attitude; and the two-way cooperative algorithm effectively suppresses the instability risk caused by the mutual coupling of the two-end vibrations.

[0149] In environments with strong vibrations, the aforementioned anti-vibration laser networking among UAV clusters can achieve stable and reliable laser links, reducing tracking errors and variance by more than 50% compared to a single-drive FSM system.

[0150] It should be noted that the abbreviations and key terms mentioned in this invention are as follows:

[0151] PAT (Pointing, Acquisition, and Tracking): Pointing, Acquisition, and Tracking, the core technology unit in laser communication systems that ensures the establishment and maintenance of beam alignment.

[0152] ROU (Range of Uncertainty): Capture the uncertain range, which is the angular spatial range that the terminal needs to scan and search due to various errors.

[0153] AOU (Angle of Uncertainty): The angle between the initial aiming direction of the transmitter or the initial direction of the detection field of view of the receiver and the actual line of sight.

[0154] FSM (Fast Steering Mirror): An optical actuator used to achieve high-bandwidth, high-precision beam deflection control.

[0155] FOV (Field of View): The angular range within which an optical system can receive light signals.

[0156] LOS (Line of Sight): The line of sight connecting the transmitter and receiver.

[0157] Lead-Ahead Aiming: An aiming technique that directs the beam towards the target's predicted future position to compensate for the target's motion during the beam's propagation time in space.

[0158] Direct Drive: A drive method in which the motor rotor is directly coupled to the load, eliminating the need for intermediate transmission mechanisms such as gears and belts, and aiming to eliminate backlash, friction and nonlinear errors.

[0159] Compared with the prior art, the above embodiments of the present invention have the following beneficial technical effects:

[0160] (1) Significantly improved capture performance: The direct-drive universal turntable eliminates transmission errors and provides a faster response; combined with intelligent scanning strategy and adaptive decision algorithm, the capture time is greatly shortened and the capture probability is improved, which is especially suitable for harsh scenarios such as narrow beacons.

[0161] (2) The tracking accuracy and stability are significantly improved: the piezoelectric-electromagnetic hybrid driven fast steering mirror (FSM) has both high bandwidth and long stroke, which can fully compensate for platform vibration from low frequency to high frequency; the bidirectional collaborative tracking algorithm improves the robustness of the link at the system level and effectively suppresses the impact of error mutual coupling and transmission delay.

[0162] (3) High level of system integration and intelligence: It adopts a highly integrated hardware platform and a unified control core to achieve seamless coordination and resource optimization of capture, tracking and early aiming functions; the system has adaptive capabilities and can dynamically adjust the control strategy according to different working modes and environmental conditions.

[0163] (4) Strong engineering practicality and easy to promote and apply: The terminal structure is simplified (such as direct drive and possible optical path multiplexing), which is expected to reduce weight, volume and power consumption, and while improving performance, it is more in line with the strict requirements of future space-based and air-based platforms for payloads.

[0164] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. The implementation schemes in the above embodiments can also be further combined or replaced. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A miniaturized, intelligent, collaboratively controlled airborne laser communication terminal, characterized in that, include: The coarse aiming unit, including the universal turntable, is used to achieve coarse positioning and attitude adjustment of the laser communication terminal over a large angle range, providing a basic positioning reference for subsequent fine aiming adjustments. The fine aiming unit, driven by a piezoelectric-electromagnetic hybrid system, works in conjunction with the coarse aiming unit to acquire the positioning information of the coarse aiming unit. This information is used to achieve high-precision small-angle correction based on coarse positioning, compensating for the positioning error of the coarse aiming unit. The intelligent control unit is electrically or signal-connected to the coarse aiming unit and the fine aiming unit, respectively, and is used to receive external control commands and scanning information fed back by the coarse aiming unit and the fine aiming unit, and generate and output corresponding drive control signals.

2. The miniaturized intelligent collaborative control airborne laser communication terminal according to claim 1, characterized in that, It also includes a two-way collaborative tracking algorithm module, which is integrated into the intelligent control unit. This module is used to construct a coarse-fine collaborative control model based on the feedback data from the coarse aiming unit and the fine aiming unit, and to dynamically coordinate the working timing and control parameters of the coarse aiming unit and the fine aiming unit to achieve collaborative tracking between the two.

3. The miniaturized intelligent collaborative control airborne laser communication terminal according to claim 2, characterized in that, The universal turntable is connected to a hollow brushless DC torque motor, which is fixedly connected to the rotation axis of the universal turntable. It is used to directly drive the universal turntable to drive the laser communication transmitting / receiving module to achieve coarse angle adjustment in two-dimensional direction.

4. A miniaturized intelligent collaborative control airborne laser communication terminal according to any one of claims 1-3, characterized in that, The precision aiming unit includes an electromagnetic drive module and a piezoelectric drive module. The electromagnetic drive module and the piezoelectric drive module are connected in parallel or in series and drive the same fast-turning mirror in a hybrid manner. The electromagnetic drive module is used to achieve medium-precision, medium-stroke attitude adjustment, while the piezoelectric drive module is used to achieve high-precision, micro-stroke attitude compensation. The intelligent control unit drives the electromagnetic drive module and / or the piezoelectric drive module to work according to the positioning error.

5. An application method for a miniaturized intelligent collaborative control airborne laser communication terminal, characterized in that, The airborne laser communication terminal as described in any one of claims 1-4 includes: S10. Initialize the parameters of the coarse aiming unit and the fine aiming unit, and set the initial state information; Obtain the offset vectors corresponding to the initial line-of-sight direction and aiming angle; S20. The coarse aiming unit enters the scanning mode and dynamically selects the optimal scanning strategy to scan based on the uncertainty range and the characteristics of the beacon light, so as to balance scanning efficiency and acquisition reliability. S30. Based on adaptive signal decision, after the scan is completed, the entire field of view data is analyzed to determine the optimal capture point and improve the capture success rate. S40. After step S30 is completed, the precision aiming unit is started, and the piezoelectric driver and electromagnetic driver drive the fast steering mirror to work in combination, and work with the intelligent control unit to achieve high-speed closed-loop feedback control. The intelligent control unit continuously receives the motion status of the other units, obtains the advance aiming angle in real time, and drives the advance aiming scope to perform compensation; at the same time, in the two-way communication mode, the intelligent control unit runs a two-way cooperative tracking algorithm to perform two-way cooperative control. In narrow beacon acquisition mode, the S50 reduces uncertainty angles through high-precision inter-satellite / satellite-to-ground calibration and performs rapid scans over small areas by utilizing the large travel capability of the precision-aiming FSM, thus completing scan optimization.

6. The application method of the miniaturized intelligent collaborative control airborne laser communication terminal according to claim 5, characterized in that, The initial state information includes position, velocity, and attitude; Obtaining the initial line-of-sight direction includes calculating an initial line-of-sight direction unit vector, wherein the formula for calculating the initial line-of-sight direction includes: ；； Where R t Let R be the initial position vector of this end. r The initial position vector of the target end; The step of obtaining the offset vector corresponding to the aiming angle includes calculating the unit vector of the advance aiming direction, wherein the calculation formula for the unit vector of the advance aiming direction includes: ； Where V rel =V r -V t V r and V t Let be the velocity vectors of the target end and the local end, respectively; τ is the estimated time required for the signal to propagate from the local end to the target end, where τ is calculated using the following formula: ； Where the speed of light is c, Rt is the initial position vector of this end, and Rr is the initial position vector of the target end.

7. The application method of the miniaturized intelligent collaborative control airborne laser communication terminal according to claim 6, characterized in that, The control core is based on Obtain the required azimuth and pitch angle commands for the corresponding omnidirectional turntable, and instruct the omnidirectional turntable to move to the predicted direction.

8. The application method of the miniaturized intelligent collaborative control airborne laser communication terminal according to claim 5, characterized in that, The optimal scanning strategy mentioned in step S20 includes: S201, The intelligent control unit captures the angular radius ρ within an uncertain range. ROU and the divergence angle θ of the beacon light used beam ; S202, if ρ ROU If a small and uncertain region can be approximated as a circle, it is classified as a "small-scale concentrated uncertainty" scenario, in which case a spiral scan is selected; the spiral scan formula includes: ； Where r(t) = r0 + Δr·t is the scanning radius, which increases linearly with time; If ρ ROU If a large and uncertain area has an irregular shape, it is determined to be a "large-scale or regular area with uncertain shape" scene, and raster scanning is selected in this case; S203. Set the scan step angle ∆s. The setting of the scan step angle ∆s shall satisfy... η is a coverage coefficient less than 1, usually taken as 0.5~0.8; at the same time, the high-sensitivity area array detector continuously collects optical signals.

9. The application method of the miniaturized intelligent collaborative control airborne laser communication terminal according to claim 5, characterized in that, The control output formula of the electromagnetic driver hybrid drive and PID control interface in step S40 includes: ； Where e(t) is the tracking error at the current moment, and K is the input signal of the controller; p k i k d These are the proportional, integral, and derivative gain coefficients, which are pre-calibrated by the system or set by an adaptive algorithm, and determine the dynamic response characteristics of the controller; U(t) is the total control quantity calculated by the controller to drive the fast steering mirror.

10. The application method of the miniaturized intelligent collaborative control airborne laser communication terminal according to claim 9, characterized in that, The bidirectional cooperative tracking algorithm includes: Based on the bidirectional tracking error coupling model, the aiming error state of the peer end and its impact on the received optical power of the local end are estimated in real time. The tracking loop parameters of the local end are dynamically adjusted, thereby suppressing the performance fluctuations caused by transmission delay and ensuring the common stability of the bidirectional link.

Images