A method for constructing and coordinating control of a laser wind measurement radar integrated optical head

Abstract

The present application relates to the technical field of wind engineering, and particularly relates to a construction and cooperative control method of a laser wind measurement radar integrated optical head, comprising: determining boundary conditions, laser and telescope parameters are selected and configured through hard constraint screening and TOPSIS sorting; seed laser branching, forming pulse introduction bias in the emission branch, and establishing gears; constructing a coaxial optical head, integrating a small mass micro-motion compensation component, and controlling the local oscillator discrete gear position of the receiving link; setting a weak reference echo channel, starting to call compensation table compensation and self-calibration; forming a mode table in an offline calibration mode, and switching according to target distance, carrier-to-noise ratio and temperature; applying bidirectional disturbance to the axial micro-displacement to compare the carrier-to-noise ratio and determine the direction, and correcting when exceeding the limit; extracting the beat frequency signal to convert the radial wind speed and reverse the wind field; and comprehensively weighting and updating the quality grading index of multiple elements. The present application realizes the consideration of low cost, miniaturization and high performance, and improves the long-term operation stability and the speed measurement reliability under various working conditions.

Description

Technical Field

[0001] This invention relates to the field of wind engineering technology, and in particular to the construction and collaborative control method of an integrated optical head for laser wind measurement radar. Background Technology

[0002] As laser wind-measuring radar is increasingly used in atmospheric boundary layer wind field detection, wind farm wind measurement, airport low-altitude wind shear monitoring, and complex terrain wind environment assessment, the requirements for system measurement accuracy, operational stability, equipment size, and engineering adaptability are also becoming more stringent. Existing laser wind-measuring radars mostly adopt a modular design for transmission and reception, with the laser, telescope, receiving link, and calibration unit often operating relatively independently, resulting in a complex system structure. To ensure detection range and velocity measurement accuracy, some devices typically rely on higher transmission power or larger aperture telescopes to enhance signal strength. While this approach can improve detection performance to some extent, it also easily leads to problems such as high overall cost, high power consumption, large structural size, high assembly and adjustment difficulty, and insufficient long-term operational stability.

[0003] On the other hand, existing systems typically lack a unified design for the matching relationship between the transmitter and receiver. The laser's pulse parameters, amplifier output, local oscillator power, and the telescope's focal position and receiver mode matching state are often set separately, making coordinated adjustments based on the target range and real-time echo status difficult. When the observation distance changes, aerosol conditions alter, or ambient temperature fluctuates, the system is prone to phenomena such as decreased receiver coupling efficiency, reference state drift, weakened beat frequency signal, and reduced velocity measurement efficiency. Especially during continuous operation, temperature rise in the laser, amplifier, optical head, and detector can cause focal shift, receiver mismatch, and local oscillator operating point drift, thus affecting the stability of the wind speed inversion results. Traditional methods usually rely on manual adjustment, external calibration, or fixed parameter operation, resulting in low automation and difficulty in meeting measurement needs under different operating conditions.

[0004] Furthermore, existing laser wind-measuring radars generally suffer from a problem in hardware design: to achieve better detection performance, they often prioritize improving component specifications rather than jointly selecting and integrating the laser and telescope at the system level. This approach leads to over-reliance on high-performance lasers, large-aperture telescopes, and complex mechanical structures, hindering system miniaturization, low power consumption, and low cost, and increasing the difficulty of later maintenance and engineering deployment. Simultaneously, if the transceiver optical heads lack built-in reference echo, self-calibration units, and online fine-tuning capabilities, the system struggles to recover to an optimal operating state promptly when external conditions change, easily causing signal quality fluctuations and measurement result discrepancies. Summary of the Invention

[0005] The purpose of this invention is to provide a method for constructing and coordinating the control of an integrated optical head for laser wind measurement radar. By establishing a joint selection mechanism for the laser and the telescope, a coaxial optical head integrating transmission, reception, reference calibration, and micro-motion compensation is constructed. Combined with self-calibration upon startup, online mode switching, thermal drift compensation, and online fine-tuning strategies, the system can maintain an optimal working state according to the mission range and real-time echo status, thereby achieving the goal of low cost, miniaturization, and high performance in wind field measurement using laser wind measurement radar.

[0006] To achieve the above objectives, this invention provides a method for constructing and coordinating the control of an integrated optical head for laser wind measurement radar, comprising the following steps: S1. Determine the system boundary conditions, establish the laser and telescope parameter sets, and select the configurations by sorting according to the equally weighted TOPSIS after hard constraint screening. S2. The continuous light output from the seed laser is split by a polarization-maintaining fiber. The transmitting branch is pulsed by a modulator and introduced into a fixed intermediate frequency bias to establish multiple sets of transmission levels. S3. Construct a coaxial optical head for transmitting and receiving. The main optical structure is fixed and integrated with a small-mass micro-motion compensation component that includes an axial micro-displacement adjuster, two orthogonal direction micro-tilt adjusters and a final stage compensation lens. The receiving link adopts local oscillator discrete range control, and the local oscillator range is adjusted according to the beat frequency main peak amplitude and DC output current. S4. Set the weak reference echo channel. At startup, call the pre-calibrated thermal drift compensation table to feed forward compensation for axial position, local oscillator range and micro tilt angle. Self-calibrate to maximize the reference echo carrier-to-noise ratio. S5. Offline calibration generates a mode table of multiple working modes. When running online, the mode table is consulted and switched based on target distance, average carrier-to-noise ratio, saturation ratio and ambient temperature. S6. During normal measurement, apply a small bidirectional disturbance to the axial micro-displacement, compare the average carrier-to-noise ratio of atmospheric echoes within the target distance window and take the higher side as the adjustment direction, and adjust the micro-tilt angles of the two orthogonal directions in the same way. When the temperature exceeds the limit, call the compensation table to correct it. S7. Extract the beat frequency signal and convert it into radial wind speed. In multi-beam observation, invert the three-dimensional wind speed components. In case of anomalies, switch to S8. S8. The quality classification is performed by combining the average carrier-to-noise ratio of the comprehensive atmospheric echo, the ratio of the main peak amplitude of the reference channel to the initial calibration value, the saturation ratio, and the radial wind speed change at adjacent times. The parameter table is updated by index weighting of the high-confidence sample operating parameters.

[0007] Preferably, in S1, the system boundary conditions include the maximum range, the main working distance range, the target distance resolution, the allowable average power consumption, and the upper limit of hardware cost; the laser candidate parameter set includes the working wavelength, seed beam width, pulse width range, repetition frequency range, amplifier output level, and single pulse energy range; the telescope candidate parameter set includes the effective aperture, effective focal length, field of view, and coaxial transceiver structure; hard constraints are used to screen out candidate schemes that do not meet the target distance resolution, minimum average carrier-to-noise ratio, upper limit of cost, or upper limit of average power consumption; the measured calibration records the average carrier-to-noise ratio, effective measurement rate, overall hardware cost, average power consumption, and total mass of the online adjustable motion optics within the target distance range; the equal-weighted TOPSIS method uses the average carrier-to-noise ratio and effective measurement rate as benefit indicators, and hardware cost, average power consumption, and total mass of the online adjustable motion optics as cost indicators to calculate the proximity.

[0008] Preferably, in S2, the polarization-maintaining fiber divides the continuous light into a transmission branch, a local oscillator branch, a reference branch, and a monitoring branch; the transmission branch forms pulses via an acousto-optic modulator or an electro-optic modulator and introduces a fixed intermediate frequency bias; the pulse width... With distance resolution satisfy: ; in, c The speed of light; Multiple sets of transmission parameter settings include at least pulse width, repetition frequency, and amplifier output settings. Shorter pulse widths are used for short-range settings, medium-range settings, and longer pulse widths for long-range settings. The monitoring branch records the transmission energy and envelope shape of each pulse in real time.

[0009] Preferably, in S3, the small mass micro-motion compensation component includes an axial micro-displacement adjuster, two orthogonal micro-tilt adjusters, and a final-stage small lens or compensation lens. The local oscillator power discrete level control logic is as follows: when the beat frequency peak amplitude is lower than the preset lower limit and the DC output does not exceed the safety upper limit, the local oscillator level is increased by one level; when the DC output exceeds the safety upper limit, the local oscillator level is decreased by one level; when the beat frequency peak amplitude meets the requirements and the DC output is within the safety range, the current level remains unchanged.

[0010] Preferably, in S4, the weak reference echo channel consists of a reference coupler, a reference fiber, and a reflector. A small portion of the emitted light enters the reference fiber through the reference coupler, is reflected at the reflector, and is recoupled into the receiving link to form an internal reference echo. The variables to be adjusted in the self-calibration state include axial micro-displacement, micro-tilt angles in two orthogonal directions, and local oscillator position. The constraint optimization objective is to maximize the carrier-to-noise ratio of the reference echo without saturation, excessive broadening of the reference spectrum, or exceeding the limit of the DC output. Temperature sensors are arranged in the laser housing, erbium-doped fiber amplifier, optical head, and detector substrate. Upon startup, a pre-calibrated thermal drift compensation table is called according to the current temperature state to perform feedforward compensation for the axial position, local oscillator position, and micro-tilt angle.

[0011] Preferably, in S5, during the offline calibration phase, the near-range mode, medium-range mode, and long-range mode are tested under the same operating conditions. For each mode, the pulse width, repetition frequency, amplifier output level, local oscillator level, axial fine adjustment position, micro-tilt angle setting, average carrier-to-noise ratio within the target distance range, saturation ratio, and effective measurement rate are recorded to form a mode table. During online operation, the controller reads the current target distance, the average carrier-to-noise ratio within the target distance window of the previous scan cycle, the saturation ratio of the previous scan cycle, and the current ambient temperature status, and selects the current working mode by looking up the table and switching the threshold.

[0012] Preferably, in S6, each adjustment cycle first reads the current reference echo carrier-to-noise ratio and the average atmospheric echo carrier-to-noise ratio within the target distance window, applies small positive and negative perturbations to the axial micro-displacement, compares the average atmospheric echo carrier-to-noise ratio within the target distance window under the two perturbations, takes the side with the higher carrier-to-noise ratio as the new adjustment direction, and adjusts the micro-tilt angles of the two orthogonal directions in the same way; when the internal reference echo carrier-to-noise ratio is basically stable while the average atmospheric echo carrier-to-noise ratio within the target distance window decreases significantly, the axial micro-displacement is adjusted first; when the internal reference echo carrier-to-noise ratio and the average atmospheric echo carrier-to-noise ratio decrease simultaneously, the micro-tilt angle and the local oscillator setting are adjusted first; when the temperature change exceeds the preset threshold, the thermal drift compensation table is first called to perform feedforward correction on the axial position, local oscillator setting, and micro-tilt angle, and then online fine-tuning is performed.

[0013] Preferably, in S7, the radial wind speed vr and the Doppler frequency shift fd satisfy: ; in, Radial wind speed, The center wavelength of the laser is [wavelength], and the main peak frequency of the beat frequency is [frequency]. The intermediate frequency offset introduced during the transmission process is ; In multi-beam scanning, VAD, or DBS observation modes, the radial wind speeds of each beam direction are used to form an observation vector. A direction cosine matrix is ​​established by combining the azimuth and elevation angles of each beam, and the three-dimensional wind speed components are solved using the least squares method. When the number of effective beams is insufficient, the matrix conditions are poor, or some beams show obvious saturation, the three-dimensional wind field results are not directly output, but are switched to S8.

[0014] Preferably, in S8, the average carrier-to-noise ratio of atmospheric echoes within the target distance window satisfies: ; in, The average carrier-to-noise ratio of atmospheric echoes within the target distance window at the current moment. The number of doors within the target distance window. The average carrier-to-noise ratio of atmospheric echoes within the target distance window at the current moment; Simultaneously, the ratio of the reference channel's main peak amplitude to the initial calibration value, the current saturation ratio, and the radial wind speed change between two adjacent moments are recorded. High confidence criteria include a high average carrier-to-noise ratio, stable reference channel status, low saturation ratio, and stable wind speed changes between adjacent moments. Medium confidence criteria include one of the above conditions not being met, but the overall situation remaining within an acceptable range. Low confidence criteria include a low carrier-to-noise ratio, significant deviation of the reference channel, high saturation ratio, or significant wind speed jumps between adjacent moments. For the pulse width, amplifier output level, axial micro-displacement, and local oscillator level in the high confidence samples, the parameter center values ​​are updated using an exponential weighting method. ; in, For the first The updated parameter center value The new parameter values ​​corresponding to the current high-confidence sample. To update the coefficients; The updated parameter center values ​​and allowable fluctuation ranges are written into the operating parameter table for the corresponding measurement range and environmental conditions, for use in the next round of self-calibration and online mode switching.

[0015] The advantages and beneficial effects of this invention compared to the prior art are: 1. By jointly selecting and matching the laser and the telescope, and constructing an integrated optical head with coaxial transmission and reception, the system can meet the requirements of range and resolution while reducing the simple dependence on high-power lasers and large-aperture telescopes, thereby helping to reduce the overall cost, power consumption and structural complexity. 2. By setting a weak reference echo channel inside the optical head, and combining it with a self-calibration and thermal drift compensation mechanism, the system can maintain a better working state when external operating conditions change and device state drifts, reducing the frequency of manual adjustment and improving long-term operational stability and engineering applicability. 3. By setting up a small-mass micro-motion compensation component, focus correction and receiver mode matching correction can be achieved without moving the main optical structure. This helps to reduce mechanical burden, reduce assembly and adjustment difficulty, and improve transmit and receive coupling efficiency and beat frequency signal quality. 4. By establishing a coordinated control mechanism for transmission parameters, reception parameters, and calibration parameters, the system can automatically switch modes and fine-tune online according to the mission range and real-time echo status, thereby improving the speed measurement efficiency and wind speed inversion reliability under different operating conditions. 5. This invention is based on the mature all-fiber coherent wind-measuring lidar technology route. The hardware implementation conditions are clear, the control process is clear, and it is easy to implement engineering and system integration. It is suitable for the development of laser wind-measuring lidar equipment that combines low cost, miniaturization and high performance.

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the construction and collaborative control method of an integrated optical head for laser wind measurement radar in an embodiment of the present invention. Detailed Implementation

[0018] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing the 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 limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" 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; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] like Figure 1 As shown, this invention provides a method for constructing and coordinating the control of an integrated optical head for laser wind measurement radar, comprising the following steps: S1. Determine the system boundary conditions, establish the laser and telescope parameter sets, and select the configurations by sorting according to the equally weighted TOPSIS after hard constraint screening. S2. The continuous light output from the seed laser is split by a polarization-maintaining fiber. The transmitting branch is pulsed by a modulator and introduced into a fixed intermediate frequency bias to establish multiple sets of transmission levels. S3. Construct a coaxial optical head for transmitting and receiving. The main optical structure is fixed and integrated with a small-mass micro-motion compensation component that includes an axial micro-displacement adjuster, two orthogonal direction micro-tilt adjusters and a final stage compensation lens. The receiving link adopts local oscillator discrete range control, and the local oscillator range is adjusted according to the beat frequency main peak amplitude and DC output current. S4. Set the weak reference echo channel. At startup, call the pre-calibrated thermal drift compensation table to feed forward compensation for axial position, local oscillator range and micro tilt angle. Self-calibrate to maximize the reference echo carrier-to-noise ratio. S5. Offline calibration generates a mode table of multiple working modes. When running online, the mode table is consulted and switched based on target distance, average carrier-to-noise ratio, saturation ratio and ambient temperature. S6. During normal measurement, apply a small bidirectional disturbance to the axial micro-displacement, compare the average carrier-to-noise ratio of atmospheric echoes within the target distance window and take the higher side as the adjustment direction, and adjust the micro-tilt angles of the two orthogonal directions in the same way. When the temperature exceeds the limit, call the compensation table to correct it. S7. Extract the beat frequency signal and convert it into radial wind speed. In multi-beam observation, invert the three-dimensional wind speed components. In case of anomalies, switch to S8. S8. The quality classification is performed by combining the average carrier-to-noise ratio of the comprehensive atmospheric echo, the ratio of the main peak amplitude of the reference channel to the initial calibration value, the saturation ratio, and the radial wind speed change at adjacent times. The parameter table is updated by index weighting of the high-confidence sample operating parameters.

[0021] In one specific embodiment, considering the wind measurement requirements from the hub height to the blade tip sweep area and the upstream flow of a wind farm, the system boundary conditions are determined as a preset maximum measurement range, main working distance range, target distance resolution, allowable average power consumption, and upper limit of hardware cost. A set of candidate parameters for the laser and a set of candidate parameters for the telescope are established. The laser candidate parameters include operating wavelength, seed beam width, pulse width range, repetition frequency range, amplifier output level, and single pulse energy range. The telescope candidate parameters include effective aperture, effective focal length, field of view, and coaxial transceiver structure. After hard-constraint screening to eliminate schemes with insufficient resolution, carrier-to-noise ratio below the minimum requirement, excessive power consumption, or excessive cost, the remaining candidate schemes are calibrated through actual measurements. The equal-weighted TOPSIS method is used to calculate the closeness using average carrier-to-noise ratio and effective measurement rate as benefit indicators, and hardware cost and average power consumption as cost indicators. The scheme with the highest closeness is selected as the basic configuration.

[0022] The subsequent steps are then executed sequentially: After the seed laser is split by a polarization-maintaining fiber, the transmitting branch generates pulses via an acousto-optic modulator and introduces a fixed intermediate frequency bias, establishing multiple transmission parameter levels; a coaxial optical head for transmitting and receiving is constructed, integrating a piezoelectric ceramic axial micro-displacement adjuster and a voice coil motor micro-tilt adjuster; the receiving link employs multi-level local oscillator discrete level control; a built-in weak reference echo channel composed of a reference coupler, a reference fiber, and a reflector is incorporated; upon startup, a thermal drift compensation table pre-calibrated according to temperature intervals is invoked to perform feedforward compensation for axial position, local oscillator level, and micro-tilt angle, self-calibrating to maximize the reference echo carrier-to-noise ratio; multiple working modes are calibrated offline to form a mode table; during online operation, the mode is switched based on the target distance, the average carrier-to-noise ratio of the previous scan cycle, the saturation ratio, and the ambient temperature; During routine measurements, a small bidirectional perturbation is applied to the axial micro-displacement. The higher side is selected as the adjustment direction by comparing the average carrier-to-noise ratio of atmospheric echoes within the target distance window. The micro-tilt angles of the two orthogonal directions are adjusted in the same way. When the temperature change exceeds the preset threshold, the thermal drift compensation table is called to correct it. The beat frequency signal is extracted and the radial wind speed is converted. During multi-beam scanning, a direction cosine matrix is ​​established and the three-dimensional wind speed components are inverted using the least squares method. Finally, the quality is graded by comprehensively considering the average carrier-to-noise ratio of atmospheric echoes, the ratio of the reference channel main peak amplitude to the initial calibration value, the saturation ratio, and the radial wind speed change at adjacent times. In the high-confidence sample, the pulse width, amplifier output level, axial micro-displacement, and local oscillator level are updated in an exponential weighted manner to update the parameter table, achieving low-cost, miniaturized, and high-performance coordinated control of the laser wind radar.

[0023] Preferably, in S1, the system boundary conditions include the maximum range, the main working distance range, the target distance resolution, the allowable average power consumption, and the upper limit of hardware cost; the laser candidate parameter set includes the working wavelength, seed beam width, pulse width range, repetition frequency range, amplifier output level, and single pulse energy range; the telescope candidate parameter set includes the effective aperture, effective focal length, field of view, and coaxial transceiver structure; hard constraints are used to screen out candidate schemes that do not meet the target distance resolution, minimum average carrier-to-noise ratio, upper limit of cost, or upper limit of average power consumption; the measured calibration records the average carrier-to-noise ratio, effective measurement rate, overall hardware cost, average power consumption, and total mass of the online adjustable motion optics within the target distance range; the equal-weighted TOPSIS method uses the average carrier-to-noise ratio and effective measurement rate as benefit indicators, and hardware cost, average power consumption, and total mass of the online adjustable motion optics as cost indicators to calculate the proximity.

[0024] In one specific embodiment, the joint selection process is as follows: System boundary conditions are set as a preset maximum range, main working distance range, target distance resolution, allowable average power consumption, and hardware cost ceiling. The laser candidate parameter set includes operating wavelength, seed beam width, pulse width range, repetition frequency range, amplifier output level, and single pulse energy range. The telescope candidate parameter set includes effective aperture, effective focal length, field of view, and transmit / receive coaxial structure. In the hard-constraint screening stage, schemes whose pulse width-corresponding resolution does not meet the target requirements are first eliminated; then, schemes with an average carrier-to-noise ratio below the minimum threshold are eliminated; subsequently, schemes with power consumption exceeding the allowable ceiling or cost exceeding the budget ceiling are eliminated. The remaining candidate schemes proceed to actual measurement and calibration. The actual measurement and calibration records the average carrier-to-noise ratio, effective measurement rate, overall hardware cost, average power consumption, and total mass of the online adjustable motion optics for each scheme within the main working distance range. In the equal-weighted TOPSIS method, the average carrier-to-noise ratio and effective measurement rate are used as benefit indicators, while hardware cost, average power consumption, and total mass of online adjustable motion optics are used as cost indicators. After normalization and Euclidean distance calculation, the scheme with the highest proximity is selected as the basic hardware configuration of the system.

[0025] Preferably, in S2, the polarization-maintaining fiber divides the continuous light into a transmission branch, a local oscillator branch, a reference branch, and a monitoring branch; the transmission branch forms pulses via an acousto-optic modulator or an electro-optic modulator and introduces a fixed intermediate frequency bias; the pulse width... With distance resolution satisfy: ; Where c is the speed of light; Multiple sets of transmission parameter settings include at least pulse width, repetition frequency, and amplifier output settings. Shorter pulse widths are used for short-range settings, medium-range settings, and longer pulse widths for long-range settings. The monitoring branch records the transmission energy and envelope shape of each pulse in real time.

[0026] In one specific embodiment, the transmission optical path setup and pulse parameter settings are as follows: A single-frequency narrow-linewidth seed laser outputs continuous light, which is then divided into a transmission branch, a local oscillator branch, a reference branch, and a monitoring branch via a polarization-maintaining fiber. The transmission branch generates pulses via an acousto-optic modulator and introduces a fixed intermediate frequency bias. The pulse width and distance resolution are inversely proportional; a shorter pulse width results in higher distance resolution, and a longer pulse width results in lower distance resolution. Multiple sets of transmission parameter levels are pre-established: the near-range level uses a shorter pulse width and a higher repetition frequency to prioritize distance resolution in the near-range range; the mid-range level uses a medium pulse width and a medium repetition frequency to balance resolution and echo energy in the mid-range range; and the long-range level uses a longer pulse width and a lower repetition frequency to prioritize echo signal strength in the long-range range. The monitoring branch records the transmission energy and envelope shape of each pulse in real time using a photodetector, serving as input for subsequent mode switching and quality control.

[0027] Preferably, in S3, the small mass micro-motion compensation component includes an axial micro-displacement adjuster, two orthogonal micro-tilt adjusters, and a final-stage small lens or compensation lens. The local oscillator power discrete level control logic is as follows: when the beat frequency peak amplitude is lower than the preset lower limit and the DC output does not exceed the safety upper limit, the local oscillator level is increased by one level; when the DC output exceeds the safety upper limit, the local oscillator level is decreased by one level; when the beat frequency peak amplitude meets the requirements and the DC output is within the safety range, the current level remains unchanged.

[0028] In one specific embodiment, the coaxial optical head and receiving link are constructed as follows: The main optical structure adopts a Cassegrain telescope structure and is fixedly installed, integrating a small-mass micro-motion compensation component. This component includes a piezoelectric ceramic axial micro-displacement adjuster, two orthogonal voice coil motor micro-tilt adjusters, and a final-stage compensation lens. The receiving link uses discrete local oscillator power control, setting multiple local oscillator levels with a fixed difference in local oscillator power between adjacent levels. The controller reads the beat frequency peak amplitude and DC output current of the balanced detector in real time: when the beat frequency peak amplitude is lower than the preset lower limit and the DC output does not exceed the safety upper limit, the local oscillator level is increased by one level; when the DC output exceeds the safety upper limit, the local oscillator level is decreased by one level; when the beat frequency peak amplitude meets the requirements and the DC output is within the safe range, the current level remains unchanged. Through this discrete level control, the local oscillator setting is always kept within a reasonable range between the available beat frequency response and the linear region of the receiving link, avoiding receiving link saturation or excessively weak beat frequency signals.

[0029] Preferably, in S4, the weak reference echo channel consists of a reference coupler, a reference fiber, and a reflector. A small portion of the emitted light enters the reference fiber through the reference coupler, is reflected at the reflector, and is recoupled into the receiving link to form an internal reference echo. The variables to be adjusted in the self-calibration state include axial micro-displacement, micro-tilt angles in two orthogonal directions, and local oscillator position. The constraint optimization objective is to maximize the carrier-to-noise ratio of the reference echo without saturation, excessive broadening of the reference spectrum, or exceeding the limit of the DC output. Temperature sensors are arranged in the laser housing, erbium-doped fiber amplifier, optical head, and detector substrate. Upon startup, a pre-calibrated thermal drift compensation table is called according to the current temperature state to perform feedforward compensation for the axial position, local oscillator position, and micro-tilt angle.

[0030] In one specific embodiment, the built-in reference echo establishment and self-calibration initiation are as follows: A weak reference echo channel is set up inside the system. This channel consists of a reference coupler, a reference fiber, and a reflector. The reflector uses a fiber optic connector with a fixed reflectivity at its end face. A small portion of the transmitted light enters the reference fiber through the reference coupler, is reflected at the reflector, and is recoupled into the receiving link, forming a stable internal reference echo. This echo does not participate in external field measurements but is only used for system state calibration. After system startup, the variables to be adjusted include axial micro-displacement, micro-tilt angles in two orthogonal directions, and the local oscillator range. The self-calibration process uses a constrained optimization approach, aiming to maximize the reference echo carrier-to-noise ratio without saturation, excessive broadening of the reference spectral width, or exceeding the DC output limit. Meanwhile, temperature sensors are arranged in the laser housing, erbium-doped fiber amplifier housing, optical head substrate, and detector substrate. When the system is started, the current temperature status is read, and the thermal drift compensation table, which is pre-calibrated at fixed intervals within the temperature range, is called to perform feedforward compensation for axial position, local oscillator setting, and micro tilt angle. Then, the above self-calibration process is performed to reduce the number of adjustments required for the system to enter the stable operating range from power-on.

[0031] Preferably, in S5, during the offline calibration phase, the near-range mode, medium-range mode, and long-range mode are tested under the same operating conditions. For each mode, the pulse width, repetition frequency, amplifier output level, local oscillator level, axial fine adjustment position, micro-tilt angle setting, average carrier-to-noise ratio within the target distance range, saturation ratio, and effective measurement rate are recorded to form a mode table. During online operation, the controller reads the current target distance, the average carrier-to-noise ratio within the target distance window of the previous scan cycle, the saturation ratio of the previous scan cycle, and the current ambient temperature status, and selects the current working mode by looking up the table and switching the threshold.

[0032] In one specific embodiment, the collaborative working mode calibration and online switching are as follows: During the offline calibration phase, unified operating condition tests are performed on the near-range mode, mid-range mode, and long-range mode respectively. The near-range mode records pulse width, repetition frequency, amplifier output level, local oscillator level, axial fine-tuning position, micro-tilt angle setting, average carrier-to-noise ratio (CNR) in the near-range interval, saturation ratio, and effective measurement rate. The mid-range mode records all the above parameters for the corresponding mid-range interval. The long-range mode records all the above parameters for the corresponding long-range interval. The above data forms a mode table and is written to the controller's memory. During online operation, the controller reads the current target distance, the average CNR within the target distance window of the previous scan cycle, the saturation ratio of the previous scan cycle, and the current ambient temperature. If the target distance is within the near-range interval and the average CNR meets the requirements, the near-range mode is invoked; if the target distance is within the mid-range interval and the average CNR meets the requirements, the mid-range mode is invoked; if the target distance exceeds the mid-range upper limit or the average CNR is too low, the long-range mode is invoked. The controller loads the pulse width, repetition frequency, amplifier output level, local oscillator level, and corresponding axial fine-tuning position and micro-tilt angle settings together, eliminating the need to recalculate complex comprehensive scores.

[0033] Preferably, in S6, each adjustment cycle first reads the current reference echo carrier-to-noise ratio and the average atmospheric echo carrier-to-noise ratio within the target distance window, applies small positive and negative perturbations to the axial micro-displacement, compares the average atmospheric echo carrier-to-noise ratio within the target distance window under the two perturbations, takes the side with the higher carrier-to-noise ratio as the new adjustment direction, and adjusts the micro-tilt angles of the two orthogonal directions in the same way; when the internal reference echo carrier-to-noise ratio is basically stable while the average atmospheric echo carrier-to-noise ratio within the target distance window decreases significantly, the axial micro-displacement is adjusted first; when the internal reference echo carrier-to-noise ratio and the average atmospheric echo carrier-to-noise ratio decrease simultaneously, the micro-tilt angle and the local oscillator setting are adjusted first; when the temperature change exceeds the preset threshold, the thermal drift compensation table is first called to perform feedforward correction on the axial position, local oscillator setting, and micro-tilt angle, and then online fine-tuning is performed.

[0034] In one specific embodiment, online fine-tuning and thermal drift compensation are performed as follows: After the system enters normal measurement, the main optical structure remains fixed, and only the small-mass micro-motion compensation component and the local oscillator setting are fine-tuned online, with adjustments executed according to a fixed cycle. Within each adjustment cycle, the current reference echo carrier-to-noise ratio (CNR) and the average atmospheric echo CNR within the target distance window are read first. Small positive and negative perturbations are applied to the axial micro-displacement, and the average atmospheric echo CNR within the target distance window under the two perturbations is compared. The side with the higher CNR is taken as the new adjustment direction, and the axial micro-displacement is updated. Subsequently, the micro-tilt angles in the two orthogonal directions are adjusted in the same way, with small positive and negative perturbations applied to each direction, and the side with the higher CNR is used to update the micro-tilt angle. When the internal reference echo CNR is basically stable, but the average atmospheric echo CNR within the target distance window decreases significantly, it is preferentially determined that the focal point and target distance matching relationship has shifted, and the axial micro-displacement is adjusted preferentially in this case. When both the internal reference echo carrier-to-noise ratio (CNR) and the atmospheric echo average CNR decrease simultaneously, it is primarily determined that the overall receiver mode matching status or the local oscillator setting has shifted. In this case, the micro-tilt angle and local oscillator setting are adjusted first. Throughout the operation, the temperature sensor continuously monitors temperature changes. When the rate of temperature change exceeds a preset threshold, the thermal drift compensation table is first used to perform feedforward correction on the axial position, local oscillator setting, and micro-tilt angle. Then, the above-mentioned online bidirectional perturbation fine-tuning is performed to suppress large temperature drifts first, followed by fine correction using small perturbations.

[0035] Preferably, in S7, the radial wind speed vr and the Doppler frequency shift fd satisfy: ; in, Radial wind speed, The center wavelength of the laser is [wavelength], and the main peak frequency of the beat frequency is [frequency]. The intermediate frequency offset introduced during the transmission process is ; In multi-beam scanning, VAD, or DBS observation modes, the radial wind speeds of each beam direction are used to form an observation vector. A direction cosine matrix is ​​established by combining the azimuth and elevation angles of each beam, and the three-dimensional wind speed components are solved using the least squares method. When the number of effective beams is insufficient, the matrix conditions are poor, or some beams show obvious saturation, the three-dimensional wind field results are not directly output, but are switched to S8.

[0036] In one specific embodiment, the beat frequency extraction and wind speed inversion are as follows: The system uses a fixed laser center wavelength. The main peak frequency of the beat frequency is extracted through digital signal processing, and the Doppler frequency shift is obtained by subtracting a fixed intermediate frequency offset. The radial wind speed is proportional to the Doppler frequency shift; a positive frequency shift indicates distance from the radar, and a negative frequency shift indicates direction towards the radar. The system uses a multi-beam scanning observation method, with each beam having a fixed azimuth and elevation angle. The radial wind speeds in each beam direction are used to form an observation vector. A direction cosine matrix is ​​established by combining the azimuth and elevation angles of each beam. The three-dimensional wind speed components are solved using the least squares method to obtain the horizontal and vertical wind speeds. If, at a certain moment, the number of effective beams is insufficient due to obstruction, or the condition number of the direction cosine matrix is ​​too large and ill-conditioned, or some beams show obvious saturation, the three-dimensional wind field results are not directly output. Instead, the system proceeds to the result classification step for low-confidence marking to avoid outputting unreliable wind field inversion results.

[0037] Preferably, in S8, the average carrier-to-noise ratio of atmospheric echoes within the target distance window satisfies: ; in, The average carrier-to-noise ratio of atmospheric echoes within the target distance window at the current moment. The number of doors within the target distance window. The average carrier-to-noise ratio of atmospheric echoes within the target distance window at the current moment; Simultaneously, the ratio of the reference channel's main peak amplitude to the initial calibration value, the current saturation ratio, and the radial wind speed change between two adjacent moments are recorded. High confidence criteria include a high average carrier-to-noise ratio, stable reference channel status, low saturation ratio, and stable wind speed changes between adjacent moments. Medium confidence criteria include one of the above conditions not being met, but the overall situation remaining within an acceptable range. Low confidence criteria include a low carrier-to-noise ratio, significant deviation of the reference channel, high saturation ratio, or significant wind speed jumps between adjacent moments. For the pulse width, amplifier output level, axial micro-displacement, and local oscillator level in the high confidence samples, the parameter center values ​​are updated using an exponential weighting method. ; in, For the first The updated parameter center value The new parameter values ​​corresponding to the current high-confidence sample. To update the coefficients; The updated parameter center values ​​and allowable fluctuation ranges are written into the operating parameter table for the corresponding measurement range and environmental conditions, for use in the next round of self-calibration and online mode switching.

[0038] In one specific embodiment, the result classification and parameter update are as follows: The target distance window is set as the main ranging interval corresponding to the current operating mode. The window contains multiple distance gates. The carrier-to-noise ratio (CNR) of each distance gate is calculated arithmetically after measurement to obtain the average CNR of the atmospheric echo within the target distance window at the current time. Simultaneously, the ratio of the reference channel's main peak amplitude to the initial calibration value, the current saturation ratio, and the radial wind speed change between two adjacent times are recorded. If the average CNR is at a high level, the reference channel is stable, the saturation ratio is low, and the wind speed change between adjacent times is stable, the sample is determined to be highly reliable. If one of the above conditions is not met but the overall condition is still within an acceptable range, it is determined to be moderately reliable. If the CNR is low, the reference channel deviates significantly, the saturation ratio is high, or the wind speed changes significantly between adjacent times, it is determined to be low reliable. Key operating parameters in the highly reliable samples are updated using an exponential weighted method. The updated parameter center value is obtained by weighted averaging of the current operating parameter value and the original parameter center value. The update coefficient controls the fusion ratio of the old and new parameters. The updated parameter center values ​​and allowable fluctuation ranges are written into the operating parameter table for the corresponding measurement range and ambient temperature conditions, for use in the next round of self-calibration and online mode switching. Low-confidence samples do not participate in parameter updates; they only trigger maintenance prompts.

[0039] This invention, through the combined selection of laser and telescope and the construction of a coaxial integrated optical head for transmission and reception, reduces the reliance on high-power lasers and large-aperture telescopes while meeting the requirements for measurement range and resolution, thereby effectively reducing the overall cost, power consumption, and structural size. By incorporating a built-in weak reference echo channel combined with a self-calibration and thermal drift compensation mechanism, the system can automatically maintain an optimal operating state when external conditions change and device state drifts, reducing the frequency of manual adjustments and improving long-term operational stability. Utilizing a small-mass micro-motion compensation component, focus correction and receiver mode matching correction are achieved without moving the main optical structure, reducing mechanical burden and assembly difficulty, and improving transmission-receiver coupling efficiency and beat frequency signal quality. By establishing a collaborative control mechanism for transmission parameters, receiver parameters, and calibration parameters, the system can automatically switch modes and perform online fine-tuning based on the mission range and real-time echo status. Combined with quality grading and exponentially weighted parameter updates, a closed-loop optimization is formed, effectively improving the velocity measurement efficiency and wind speed inversion reliability under different operating conditions, achieving a balance between low cost, miniaturization, and high performance.

[0040] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for constructing and coordinating the control of an integrated optical head for laser wind measurement radar, characterized in that, Includes the following steps: S1. Determine the system boundary conditions, establish the laser and telescope parameter sets, and select the configurations by sorting according to the equally weighted TOPSIS after hard constraint screening. S2. The continuous light output from the seed laser is split by a polarization-maintaining fiber. The transmitting branch is pulsed by a modulator and introduced into a fixed intermediate frequency bias to establish multiple sets of transmission levels. S3. Construct a coaxial optical head for transmitting and receiving. The main optical structure is fixed and integrated with a small-mass micro-motion compensation component that includes an axial micro-displacement adjuster, two orthogonal direction micro-tilt adjusters and a final stage compensation lens. The receiving link adopts local oscillator discrete range control, and the local oscillator range is adjusted according to the beat frequency main peak amplitude and DC output current. S4. Set the weak reference echo channel. At startup, call the pre-calibrated thermal drift compensation table to feed forward compensation for axial position, local oscillator range and micro tilt angle. Self-calibrate to maximize the reference echo carrier-to-noise ratio. S5. Offline calibration generates a mode table of multiple working modes. When running online, the mode table is consulted and switched based on target distance, average carrier-to-noise ratio, saturation ratio and ambient temperature. S6. During normal measurement, apply a small bidirectional disturbance to the axial micro-displacement, compare the average carrier-to-noise ratio of atmospheric echoes within the target distance window and take the higher side as the adjustment direction, and adjust the micro-tilt angles of the two orthogonal directions in the same way. When the temperature exceeds the limit, call the compensation table to correct it. S7. Extract the beat frequency signal and convert it into radial wind speed. In multi-beam observation, invert the three-dimensional wind speed components. In case of anomalies, switch to S8. S8. The quality classification is performed by combining the average carrier-to-noise ratio of the integrated atmospheric echo, the ratio of the main peak amplitude of the reference channel to the initial calibration value, the saturation ratio, and the radial wind speed change at adjacent times. The parameter table is updated by using an exponential weighting method for the operating parameters in the high-confidence sample.

2. The construction and collaborative control method of an integrated optical head for laser wind measurement radar according to claim 1, characterized in that, In S1, the system boundary conditions include maximum range, main working distance range, target distance resolution, allowable average power consumption, and upper limit of hardware cost; the laser candidate parameter set includes working wavelength, seed beam width, pulse width range, repetition frequency range, amplifier output level, and single pulse energy range; the telescope candidate parameter set includes effective aperture, effective focal length, field of view, and coaxial transceiver structure; hard constraints are used to screen out candidate schemes that do not meet the target distance resolution, minimum average carrier-to-noise ratio, upper limit of cost, or upper limit of average power consumption; the measured calibration records the average carrier-to-noise ratio, effective measurement rate, overall hardware cost, average power consumption, and total mass of online adjustable moving optics within the target distance range; the equal-weighted TOPSIS method uses the average carrier-to-noise ratio and effective measurement rate as benefit indicators, and hardware cost, average power consumption, and total mass of online adjustable moving optics as cost indicators to calculate the proximity.

3. The construction and collaborative control method of an integrated optical head for laser wind measurement radar according to claim 2, characterized in that, In S2, the polarization-maintaining fiber divides the continuous light into a transmission branch, a local oscillator branch, a reference branch, and a monitoring branch; the transmission branch generates pulses via an acousto-optic modulator or an electro-optic modulator and introduces a fixed intermediate frequency bias; the pulses... width With distance resolution satisfy: ； in, c The speed of light; Multiple sets of transmission parameter settings include at least pulse width, repetition frequency, and amplifier output settings. Shorter pulse widths are used for short-range settings, medium-range settings, and longer pulse widths for long-range settings. The monitoring branch records the transmission energy and envelope shape of each pulse in real time.

4. The construction and collaborative control method of an integrated optical head for laser wind measurement radar according to claim 3, characterized in that, In S3, the small mass micro-motion compensation component includes an axial micro-displacement adjuster, two orthogonal micro-tilt adjusters, and a final-stage small lens or compensation lens. The local oscillator power discrete level control logic is as follows: when the beat frequency peak amplitude is lower than the preset lower limit and the DC output does not exceed the safety upper limit, the local oscillator level is increased by one level; when the DC output exceeds the safety upper limit, the local oscillator level is decreased by one level; when the beat frequency peak amplitude meets the requirements and the DC output is within the safety range, the current level remains unchanged.

5. The construction and collaborative control method of an integrated optical head for laser wind measurement radar according to claim 4, characterized in that, In S4, the weak reference echo channel consists of a reference coupler, a reference fiber and a reflector. A small portion of the emitted light enters the reference fiber through the reference coupler, and after being reflected at the reflector, it is recoupled into the receiving link to form an internal reference echo. The variables to be adjusted in the self-calibration state include axial micro-displacement, micro-tilt angles in two orthogonal directions, and local oscillator position. The constraint optimization objective is to maximize the reference echo carrier-to-noise ratio without saturation, excessive broadening of the reference spectrum, or overlimiting the DC output. Temperature sensors are located in the laser housing, erbium-doped fiber amplifier, optical head, and detector substrate. Upon startup, a pre-calibrated thermal drift compensation table is called based on the current temperature state to perform feedforward compensation for the axial position, local oscillator position, and micro-tilt angle.

6. The construction and collaborative control method of an integrated optical head for laser wind measurement radar according to claim 5, characterized in that, In S5, during the offline calibration phase, unified operating condition tests are performed on the near-range mode, medium-range mode, and long-range mode respectively. For each mode, the pulse width, repetition frequency, amplifier output level, local oscillator level, axial fine adjustment position, micro-tilt angle setting value, average carrier-to-noise ratio within the target distance range, saturation ratio, and effective measurement rate are recorded to form a mode table. During online operation, the controller reads the current target distance, the average carrier-to-noise ratio within the target distance window of the previous scan cycle, the saturation ratio of the previous scan cycle, and the current ambient temperature status, and selects the current working mode by looking up the table and switching the threshold.

7. The construction and collaborative control method of an integrated optical head for laser wind measurement radar according to claim 6, characterized in that, In step S6, each adjustment cycle first reads the current reference echo carrier-to-noise ratio and the average atmospheric echo carrier-to-noise ratio within the target distance window. Small positive and negative perturbations are applied to the axial micro-displacement. The average atmospheric echo carrier-to-noise ratio within the target distance window is compared under both perturbations. The side with the higher carrier-to-noise ratio is taken as the new adjustment direction, and the micro-tilt angles in the two orthogonal directions are adjusted in the same way. When the internal reference echo carrier-to-noise ratio is basically stable while the average atmospheric echo carrier-to-noise ratio within the target distance window decreases significantly, the axial micro-displacement is adjusted first. When both the internal reference echo carrier-to-noise ratio and the average atmospheric echo carrier-to-noise ratio decrease simultaneously, the micro-tilt angle and local oscillator setting are adjusted first. When the temperature change exceeds a preset threshold, the thermal drift compensation table is first called to perform feedforward correction on the axial position, local oscillator setting, and micro-tilt angle before online fine-tuning is performed.

8. The construction and collaborative control method of an integrated optical head for laser wind measurement radar according to claim 7, characterized in that, In S7, the radial wind speed vr and the Doppler frequency shift fd satisfy: ； in, Radial wind speed, The center wavelength of the laser is [wavelength], and the main peak frequency of the beat frequency is [frequency]. The intermediate frequency offset introduced during the transmission process is ; In multi-beam scanning, VAD, or DBS observation modes, the radial wind speeds of each beam direction are used to form an observation vector. A direction cosine matrix is ​​established by combining the azimuth and elevation angles of each beam, and the three-dimensional wind speed components are solved using the least squares method. When the number of effective beams is insufficient, the matrix conditions are poor, or some beams show obvious saturation, the three-dimensional wind field results are not directly output, but are switched to S8.

9. The construction and collaborative control method of an integrated optical head for laser wind measurement radar according to claim 8, characterized in that, In S8, the average carrier-to-noise ratio of atmospheric echoes within the target distance window satisfies: ； in, The average carrier-to-noise ratio of atmospheric echoes within the target distance window at the current moment. The number of doors within the target distance window. The average carrier-to-noise ratio of atmospheric echoes within the target distance window at the current moment; Simultaneously, the ratio of the reference channel's main peak amplitude to the initial calibration value, the current saturation ratio, and the radial wind speed change between two adjacent moments are recorded. High confidence criteria include a high average carrier-to-noise ratio, stable reference channel status, low saturation ratio, and stable wind speed changes between adjacent moments. Medium confidence criteria include one of the above conditions not being met, but the overall situation remaining within an acceptable range. Low confidence criteria include a low carrier-to-noise ratio, significant deviation of the reference channel, high saturation ratio, or significant wind speed jumps between adjacent moments. For the pulse width, amplifier output level, axial micro-displacement, and local oscillator level in the high confidence samples, the parameter center values ​​are updated using an exponential weighting method. ； in, , The first , The updated parameter center value The new parameter values ​​corresponding to the current high-confidence sample. To update the coefficients; The updated parameter center values ​​and allowable fluctuation ranges are written into the operating parameter table for the corresponding measurement range and environmental conditions, for use in the next round of self-calibration and online mode switching.

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