A sea microwave antenna attitude calibration system fusing a Beidou inertial navigation system

Abstract

This invention discloses a marine microwave antenna attitude calibration system integrating BeiDou inertial navigation, belonging to the field of marine antenna attitude control technology, and is used to solve the problem of antenna misalignment caused by wind and waves. The invention uses controllable adjustable channels in three directions (azimuth, pitch, and roll) to carry a large-aperture microwave parabolic antenna, collecting BeiDou positioning data, heading data, and antenna load-end attitude data to generate antenna attitude observation data. Based on the location of the local marine platform, the location of the remote communication station, the antenna installation reference angle, and the actual rotation angle of the three axes, a microwave link target pointing reference is generated, attitude deviation is calculated, and a three-axis calibration command is generated for reverse compensation. Simultaneously, the target pointing reference, installation reference angle, and control parameters are corrected based on link quality data, improving the stability of the microwave communication link under wind and wave disturbances at sea.

Description

Technical Field

[0001] This invention relates to the field of marine antenna attitude control technology, and more specifically, to a marine microwave antenna attitude calibration system integrating BeiDou inertial navigation. Background Technology

[0002] In the field of marine microwave communication, offshore drilling platforms, offshore production platforms, and shore-based communication stations typically rely on large-aperture microwave parabolic antennas to establish directional communication links, enabling the stable transmission of production data, monitoring data, dispatch instructions, and emergency communication information. Such communication links have high requirements for antenna pointing accuracy, elevation attitude, and polarization attitude. Typically, it is necessary to install, align, and adjust the attitude of the microwave antenna using antenna brackets, rotation mechanisms, elevation adjustment mechanisms, or motorized pan-tilt units. Existing technical solutions mostly focus on static alignment after antenna installation, or routine adjustments to the antenna azimuth and elevation angles according to the communication link direction to ensure that the antenna main lobe points towards the other end of the communication station. The technical implementation involves the coordinated cooperation of microwave communication equipment, antenna mechanical adjustment mechanisms, and attitude control equipment.

[0003] However, offshore drilling platforms are constantly subjected to the effects of wave fluctuations, wind loads, platform vibrations, and equipment operation disturbances. The platform itself experiences roll, pitch, and azimuth shifts. Large-aperture microwave parabolic antennas, with their narrow beams and large inertial loads, are highly sensitive to minute attitude changes. Fixed supports or ordinary pan-tilt units cannot directly perceive the true attitude of the antenna load end, nor can they unify the platform position, the communication station position, the antenna mounting reference angle, and the actual three-axis rotation positions for target pointing calibration. This leads to horizontal pointing deviation, pitch pointing deviation, and polarization attitude deviation during platform swaying. Such deviations cause a decrease in received signal strength, a reduction in signal-to-noise ratio, and an increase in bit error rate or packet loss rate, potentially resulting in microwave communication link interruption. Therefore, it is necessary to provide a marine microwave antenna attitude calibration system integrating BeiDou inertial navigation to achieve dynamic calibration and stable maintenance of microwave antenna target pointing under swaying conditions on offshore platforms. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the following solution is proposed to solve the problem of antenna misalignment caused by wind and waves in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A marine microwave antenna attitude calibration system integrating BeiDou inertial navigation includes an antenna load adjustment module, a BeiDou inertial navigation acquisition module, a target pointing calculation module, a three-axis active compensation module, and a link feedback correction module;

[0007] The antenna support adjustment module is used to support the large-aperture microwave parabolic antenna and to mechanically adjust the overall pointing of the antenna through an azimuth rotation mechanism, a pitch compensation mechanism and a roll compensation mechanism.

[0008] The BeiDou inertial navigation acquisition module is used to collect BeiDou positioning data, heading data, angular velocity data, acceleration data, and attitude angle data from the local marine platform, and generate antenna attitude observation data.

[0009] The target pointing calculation module is used to generate a microwave link target pointing reference based on the location of the local offshore platform, the location of the remote communication station, the antenna installation reference angle, microwave link parameters, and the actual rotation angle of the three axes, and to calculate the attitude deviation of the antenna relative to the microwave link target pointing reference.

[0010] The three-axis active compensation module is used to generate azimuth calibration commands, pitch calibration commands and roll calibration commands based on attitude deviations, and drive the corresponding azimuth rotation mechanism, pitch compensation mechanism and roll compensation mechanism to perform reverse compensation so that the antenna keeps the target pointing.

[0011] The link feedback correction module is used to collect microwave communication link quality data and correct the control parameters of the microwave link target pointing reference, antenna installation reference angle, and three-axis active compensation module.

[0012] Furthermore, the antenna load adjustment module includes an azimuth rotation execution unit, a pitch compensation execution unit, a roll compensation execution unit, and an antenna load platform;

[0013] The azimuth rotation execution unit includes an azimuth rotation mechanism, the pitch compensation execution unit includes a pitch compensation mechanism, and the roll compensation execution unit includes a roll compensation mechanism.

[0014] A large-aperture microwave parabolic antenna is mounted on the antenna load platform. The azimuth rotation execution unit is used to receive azimuth calibration commands and adjust the overall azimuth angle of the antenna. The pitch compensation execution unit is used to receive pitch calibration commands and adjust the pitch attitude of the antenna. The roll compensation execution unit is used to receive roll calibration commands and adjust the lateral attitude of the antenna, so that the antenna load adjustment module forms a controllable attitude adjustment channel in three directions: azimuth, pitch and roll.

[0015] Furthermore, the antenna bearing adjustment module also includes a three-axis angle feedback component, which collects the actual rotation angle positions of the azimuth rotation execution unit, the pitch compensation execution unit, and the roll compensation execution unit respectively, and generates the actual azimuth rotation angle, the actual pitch rotation angle, and the actual roll rotation angle.

[0016] The target pointing calculation module uses the actual azimuth angle, actual pitch angle, and actual roll angle as the actual three-axis angle positions to correct the microwave link target pointing reference and attitude deviation.

[0017] Furthermore, the BeiDou inertial navigation acquisition module includes a BeiDou receiving unit, an inertial measurement unit, and a time synchronization unit;

[0018] The Beidou receiving unit is used to collect Beidou positioning data and heading data of the local offshore platform. The inertial measurement unit is rigidly installed on the antenna load platform of the antenna load adjustment module and is used to directly collect angular velocity data, acceleration data and attitude angle data of the large-aperture microwave parabolic antenna load end.

[0019] The time synchronization unit is used to time-mark and align the sampling times of BeiDou positioning data, heading data, angular velocity data, acceleration data, and attitude angle data to form an antenna attitude sampling sequence with a unified time reference.

[0020] Furthermore, the BeiDou inertial navigation acquisition module performs attitude fusion processing on the antenna attitude sampling sequence, the attitude fusion processing including:

[0021] The initial attitude of the antenna load is determined based on the heading data and attitude angle data. The initial attitude is continuously recursively derived based on the angular velocity data. The drift correction of the derived attitude is performed based on the acceleration data. The corrected attitude is then processed by Kalman filtering and complementary filtering to generate antenna attitude observation data.

[0022] Antenna attitude observation data includes azimuth attitude, pitch attitude, roll attitude, corresponding attitude change rate, and low-frequency swaying trend extracted from the attitude change rate.

[0023] Furthermore, the target pointing calculation module determines the spatial pointing direction of the microwave communication link based on the location of the local offshore platform and the location of the remote communication station. It establishes the attitude transformation relationship between the antenna installation coordinate system and the geographic coordinate system based on the antenna installation reference angle and the actual rotation angle of the three axes, and transforms the spatial pointing direction to the antenna installation coordinate system to generate a microwave link target pointing reference that includes the target azimuth direction and the target elevation direction.

[0024] Furthermore, the target pointing calculation module compares the azimuth attitude in the antenna attitude observation data with the target azimuth direction, compares the pitch attitude with the target pitch direction, and compares the roll attitude with the attitude maintenance reference to obtain the azimuth deviation, pitch deviation, and roll deviation.

[0025] Attitude deviation is generated based on azimuth deviation, pitch deviation, and roll deviation. Azimuth deviation is used to characterize the deviation of the antenna's horizontal pointing direction from the target's azimuth direction, pitch deviation is used to characterize the deviation of the antenna's pitch pointing direction from the target's pitch direction, and roll deviation is used to characterize the deviation of the antenna's polarization attitude from the attitude maintenance reference.

[0026] Furthermore, the three-axis active compensation module includes an attitude outer loop control unit, an angular velocity inner loop control unit, and a feedforward compensation unit;

[0027] The attitude outer loop control unit is used to generate attitude convergence control quantity based on attitude deviation, the angular velocity inner loop control unit is used to generate disturbance suppression control quantity based on attitude change rate in antenna attitude observation data, and the feedforward compensation unit is used to generate wave feedforward compensation quantity based on low-frequency swaying trend in antenna attitude observation data.

[0028] Furthermore, the three-axis active compensation module determines the three-axis target compensation direction according to the attitude convergence control quantity, determines the three-axis compensation response speed according to the disturbance suppression control quantity, and pre-corrects the three-axis target compensation direction according to the wave feedforward compensation quantity, generates azimuth calibration command, pitch calibration command and roll calibration command, and drives the azimuth rotation execution unit, pitch compensation execution unit and roll compensation execution unit to drive the corresponding mechanism to perform compensation actions in the opposite direction to the attitude deviation.

[0029] Furthermore, the microwave communication link quality data collected by the link feedback correction module includes at least one of the following: received signal strength, signal-to-noise ratio, bit error rate, packet loss rate, and link interruption flag.

[0030] The link feedback correction module determines the link quality change status after attitude compensation based on the corresponding change relationship between microwave communication link quality data and attitude deviation, and corrects the control parameters of microwave link target pointing reference, antenna installation reference angle and three-axis active compensation module when the link quality deteriorates.

[0031] The technical effects and advantages of the present invention, which integrates BeiDou inertial navigation with a marine microwave antenna attitude calibration system, are as follows:

[0032] This invention forms controllable attitude adjustment channels in three directions—azimuth, pitch, and roll—through an antenna-borne adjustment module, and obtains the actual rotation angle positions of the three axes by combining a three-axis angle feedback component. This allows the antenna attitude adjustment to no longer rely on theoretical command angles, but to perform closed-loop calibration based on the actual mechanical attitude. The BeiDou inertial navigation acquisition module collects BeiDou positioning data, heading data, and angular velocity data, acceleration data, and attitude angle data from the antenna load end. After time alignment, continuous recursion, drift correction, Kalman filtering, and complementary filtering, antenna attitude observation data containing azimuth attitude, pitch attitude, roll attitude, attitude change rate, and low-frequency sway change trend are generated.

[0033] Then, the target pointing calculation module generates a microwave link target pointing reference based on the location of the local offshore platform, the location of the remote communication station, the antenna installation reference angle, and the actual rotation angle of the three axes, and calculates the attitude deviation. The three-axis active compensation module further combines the attitude convergence control quantity, the disturbance suppression control quantity, and the wave feedforward compensation quantity to generate azimuth calibration command, pitch calibration command, and roll calibration command to achieve reverse compensation for low-frequency wave swaying and platform attitude disturbance.

[0034] Meanwhile, the link feedback correction module corrects the target pointing reference, antenna installation reference angle, and control parameters based on the received signal strength, signal-to-noise ratio, bit error rate, packet loss rate, and link interruption flag, thereby reducing antenna misalignment, link attenuation, and communication interruption caused by wind and waves on the offshore platform, and improving the pointing accuracy, anti-interference capability, and operational stability of the offshore microwave communication link. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a marine microwave antenna attitude calibration system integrating BeiDou inertial navigation according to the present invention.

[0036] Figure 2 This is a schematic diagram illustrating the workflow of a marine microwave antenna attitude calibration system integrating BeiDou inertial navigation, as described in this invention. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In order to achieve the above objectives, Figure 1 A schematic diagram of the structure of a marine microwave antenna attitude calibration system integrating BeiDou inertial navigation is given in this invention, which specifically includes an antenna load adjustment module, a BeiDou inertial navigation acquisition module, a target pointing calculation module, a three-axis active compensation module, and a link feedback correction module.

[0039] like Figure 2 As shown, during operation, the Beidou inertial navigation acquisition module first generates antenna attitude observation data, then the target pointing calculation module generates microwave link target pointing reference and calculates attitude deviation, and then the three-axis active compensation module generates three-axis calibration command, drives the antenna load adjustment module to perform reverse compensation, and uses the actual three-axis rotation position and microwave communication link quality data to provide feedback correction for the attitude calibration process.

[0040] The antenna support adjustment module is used to support the large-aperture microwave parabolic antenna and mechanically adjusts the overall pointing of the antenna through an azimuth rotation mechanism, a pitch compensation mechanism, and a roll compensation mechanism. Specific implementation details include:

[0041] The antenna load adjustment module is used to provide a mounting load, three-axis attitude adjustment and rotation feedback basis for large-aperture microwave parabolic antennas;

[0042] The large-aperture microwave parabolic antenna refers to a directional parabolic reflector antenna used for establishing marine microwave communication links, which includes a parabolic reflector, a feed assembly, an antenna back frame, and a mounting base.

[0043] The parabolic reflector is used to form a directional beam of microwave signals radiated or received by the feed assembly. The feed assembly is located at the focal point of the parabolic reflector to realize the transmission and reception of microwave signals. The antenna back frame is used to support the parabolic reflector and maintain its structural shape. The mounting base is used to fix it to the antenna load platform.

[0044] The term "large aperture" is an engineering description relative to a small communication antenna. In this embodiment, a microwave parabolic antenna with an aperture of 2.4 meters can be used, or other aperture microwave parabolic antennas can be selected according to the link distance, operating frequency band, and gain requirements.

[0045] The antenna load adjustment module includes an azimuth rotation execution unit, a pitch compensation execution unit, a roll compensation execution unit, and an antenna load platform. The antenna load platform is a rigid load-bearing component for mounting a large-aperture microwave parabolic antenna. It is provided with a mounting interface that matches the base of the large-aperture microwave parabolic antenna. The large-aperture microwave parabolic antenna is fixed to the antenna load platform through the mounting interface, so that the antenna load platform and the large-aperture microwave parabolic antenna maintain synchronous movement during attitude changes.

[0046] The azimuth rotation execution unit includes an azimuth rotation mechanism, which receives the azimuth calibration command output by the three-axis active compensation module and adjusts the overall azimuth angle of the large-aperture microwave parabolic antenna according to the azimuth calibration command. The overall azimuth angle refers to the rotation position of the large-aperture microwave parabolic antenna in the horizontal plane relative to the preset azimuth zero position, which can be determined according to the installation reference direction of the offshore platform during installation and commissioning. When executing the azimuth calibration command, the azimuth rotation execution unit drives the azimuth rotation mechanism to rotate the antenna load platform and the large-aperture microwave parabolic antenna on it as a whole, so that the antenna's horizontal pointing is closer to the target azimuth direction.

[0047] The pitch compensation execution unit includes a pitch compensation mechanism, which receives pitch calibration commands output by the three-axis active compensation module and adjusts the pitch attitude of the large-aperture microwave parabolic antenna according to the pitch calibration commands. The pitch attitude refers to the attitude change of the large-aperture microwave parabolic antenna along the vertical plane relative to the installation reference pitch position, which can be specifically understood as the change in the antenna aperture's upward or downward state. The pitch compensation execution unit drives the antenna load platform to generate pitch direction angle adjustment through the pitch compensation mechanism, thereby compensating for the antenna pitch deviation caused by the forward and backward undulations or pitching motion of the offshore platform.

[0048] The roll compensation execution unit includes a roll compensation mechanism, which receives roll calibration commands from the three-axis active compensation module and adjusts the lateral attitude of the large-aperture microwave parabolic antenna according to the roll calibration commands. The lateral attitude refers to the lateral tilt state of the large-aperture microwave parabolic antenna around its front-back direction or close to its pointing direction. This attitude change affects the antenna polarization direction and stable pointing state. The roll compensation execution unit drives the antenna load platform to adjust the lateral angle through the roll compensation mechanism to counteract the lateral tilt of the antenna caused by the left-right swaying of the offshore platform.

[0049] Thus, the azimuth rotation execution unit forms a controllable attitude adjustment channel in the azimuth direction, the pitch compensation execution unit forms a controllable attitude adjustment channel in the pitch direction, and the roll compensation execution unit forms a controllable attitude adjustment channel in the roll direction; the controllable attitude adjustment channel refers to a closed-loop execution path that can receive corresponding calibration commands, drive the corresponding mechanism to perform angle adjustment, and provide the actual rotation position to the subsequent calculation process.

[0050] The three controllable attitude adjustment channels work together to enable the antenna-bearing adjustment module to mechanically adjust the overall pointing of the large-aperture microwave parabolic antenna in three directions: azimuth, pitch, and roll.

[0051] In a further specific embodiment, the antenna bearing adjustment module also includes a three-axis angle feedback component. The three-axis angle feedback component is respectively set with the azimuth rotation execution unit, the pitch compensation execution unit and the roll compensation execution unit, and is used to collect the actual rotation angle position of each execution unit at the current moment. The three-axis angle feedback component can be an absolute angle encoder, a rotary transformer or other angle detection component that can output the axial angle position. It is preferred to use an absolute angle encoder so that the current position of each axis can be directly obtained after power failure recovery or restart.

[0052] The three-axis angle feedback component acquires the current rotation angle of the azimuth rotation execution unit and generates the actual azimuth rotation angle. The actual azimuth rotation angle refers to the current rotation angle of the azimuth rotation execution unit relative to the preset azimuth zero position, which is used to characterize the actual position of the large-aperture microwave parabolic antenna in the horizontal pointing direction.

[0053] The three-axis angle feedback component acquires the current rotation angle of the pitch compensation execution unit and generates the actual pitch angle. The actual pitch angle refers to the current rotation angle of the pitch compensation execution unit relative to the preset pitch zero position, which is used to characterize the actual position of the large-aperture microwave parabolic antenna in the pitch direction.

[0054] The three-axis angle feedback component acquires the current rotation angle of the roll compensation execution unit and generates the actual roll rotation angle. The actual roll rotation angle refers to the current rotation angle of the roll compensation execution unit relative to the preset roll zero position, which is used to characterize the actual position of the large-aperture microwave parabolic antenna in the lateral attitude direction.

[0055] During the installation and commissioning phase, the preset azimuth zero position, preset pitch zero position, and preset roll zero position are determined through mechanical installation reference and initial calibration process, respectively. After the zero position is determined, the three-axis angle feedback component continuously collects the actual azimuth angle, actual pitch angle, and actual roll angle according to the set sampling period during system operation, and binds the three with the corresponding sampling time to form the actual three-axis angle position.

[0056] The actual rotation position of the three axes is not a single angle, but rather a combination of the actual azimuth angle, the actual pitch angle, and the actual roll angle, which constitutes the current three-axis attitude execution position data and is used to reflect the actual mechanical attitude that the antenna bearing adjustment module has executed.

[0057] After receiving the actual rotation angle positions of the three axes, the target pointing calculation module uses the actual azimuth rotation angle to correct the horizontal pointing relationship in the microwave link target pointing reference, uses the actual pitch rotation angle to correct the elevation pointing relationship in the microwave link target pointing reference, and uses the actual roll rotation angle to correct the polarization attitude maintenance relationship of the large-aperture microwave parabolic antenna.

[0058] Through the above processing, when generating or updating the microwave link target pointing reference, the target pointing calculation module not only considers the position of the local offshore platform, the position of the remote communication station, and the antenna installation reference angle, but also simultaneously considers the actual mechanical positions of the azimuth rotation execution unit, the pitch compensation execution unit, and the roll compensation execution unit, thereby avoiding inaccurate attitude deviation judgment caused by calculating solely based on theoretical command angles.

[0059] When the three-axis active compensation module outputs azimuth calibration command, pitch calibration command and roll calibration command, the antenna bearing adjustment module drives the action of each execution unit according to the corresponding calibration command.

[0060] The three-axis angle feedback component synchronously collects the actual azimuth angle, actual pitch angle, and actual roll angle after the action, and sends the updated three-axis actual angle position to the target pointing calculation module;

[0061] The target pointing calculation module corrects the microwave link target pointing reference and attitude deviation based on the updated actual rotation position of the three axes, so that the subsequently generated azimuth calibration command, pitch calibration command and roll calibration command can be adjusted based on the current actual execution position of the antenna. This forms an attitude calibration process that combines the overall pointing mechanical adjustment of the antenna with angle feedback correction.

[0062] The BeiDou inertial navigation acquisition module is used to collect BeiDou positioning data, heading data, and angular velocity, acceleration, and attitude angle data from the local offshore platform, generating antenna attitude observation data. Specific implementation details include:

[0063] The BeiDou inertial navigation acquisition module acquires the position and heading of the local offshore platform, as well as the real-time attitude changes of the large-aperture microwave parabolic antenna load. It also organizes data from different sources into antenna attitude observation data that can be used by the target pointing calculation module and the three-axis active compensation module. The BeiDou inertial navigation acquisition module includes a BeiDou receiving unit, an inertial measurement unit, and a time synchronization unit.

[0064] The BeiDou receiving unit is installed on the local offshore platform. The relative position of its antenna receiving position and the installation position of the large-aperture microwave parabolic antenna are predetermined. The BeiDou receiving unit continuously collects BeiDou positioning data and heading data from the local offshore platform. The BeiDou positioning data characterizes the position of the local offshore platform in the geographic coordinate system and includes at least longitude, latitude, and altitude information. The heading data characterizes the orientation of the local offshore platform relative to geographic north and can be obtained from BeiDou dual-antenna direction finding, BeiDou integrated navigation equipment, or BeiDou inertial navigation equipment.

[0065] In actual operation, the BeiDou receiving unit outputs BeiDou positioning data and heading data according to the set sampling period, and adds the collection time to each set of data.

[0066] The inertial measurement unit is rigidly mounted on the antenna load platform of the antenna load adjustment module. Rigid mounting means that the inertial measurement unit and the antenna load platform are connected by bolts, positioning pins, mounting bases or equivalent fixed structures, so that the inertial measurement unit moves synchronously with the antenna load platform during operation without relative shaking.

[0067] The inertial measurement unit (IMU) is used to collect angular velocity data, acceleration data, and attitude angle data from the antenna load. The angular velocity data characterizes the rate of change of angular motion of the antenna load in the azimuth, pitch, and roll directions. The acceleration data characterizes the linear acceleration change state of the antenna load in the three spatial directions and can be used to determine the drift trend generated during attitude recursion. The attitude angle data characterizes the azimuth, pitch, and roll attitude of the antenna load at the current moment. The data output by the IMU is recorded corresponding to the acquisition time, forming an inertial measurement data stream.

[0068] The time synchronization unit is used to time-mark and align the sampling times of BeiDou positioning data, heading data, angular velocity data, acceleration data, and attitude angle data. Since the sampling frequencies of the BeiDou receiving unit and the inertial measurement unit may be different, the time synchronization unit uses a unified time reference to organize the acquisition times of each set of data.

[0069] Before aligning the sampling times, the time synchronization unit also performs validity checks on the BeiDou positioning data, heading data, angular velocity data, acceleration data, and attitude angle data. The validity checks include checking whether the data has missing sampling times, interrupted data frames, exceeds the device's range, has abrupt changes in attitude angles, or has repeated unchanged times.

[0070] When the data at a certain sampling moment meets the validity requirements, the time synchronization unit writes the data into the antenna attitude sampling sequence.

[0071] When the data at a certain sampling time does not meet the validity requirements, the time synchronization unit adds an invalid mark to the data and performs hold or interpolation processing based on the data at adjacent valid sampling times.

[0072] If the BeiDou positioning data or heading data is temporarily invalid, but the angular velocity data, acceleration data and attitude angle data output by the inertial measurement unit are valid, the BeiDou inertial navigation acquisition module will temporarily maintain the continuity of the antenna attitude observation data based on the data output by the inertial measurement unit.

[0073] If the output data of the inertial measurement unit is invalid, the generation of new antenna attitude observation data will be paused, and the attitude result of the previous valid sampling time will be maintained until valid data is obtained again.

[0074] For data with the same sampling time or within the allowable time error range, the time synchronization unit classifies them into the same sampling time.

[0075] For data whose sampling times are not completely consistent, the time synchronization unit performs interpolation or maintains the data according to the order of data changes between adjacent sampling times, so that BeiDou positioning data, heading data, angular velocity data, acceleration data and attitude angle data have a corresponding relationship at the same point in time.

[0076] After time alignment is completed, the time synchronization unit generates the antenna attitude sampling sequence according to the sampling time order.

[0077] The antenna attitude sampling sequence includes multiple sampling entries arranged in chronological order. Each sampling entry includes at least the sampling time, BeiDou positioning data, heading data, angular velocity data, acceleration data, and attitude angle data.

[0078] Using the antenna attitude sampling sequence, subsequent attitude fusion processing can read the position and heading status of the local offshore platform at the same time reference, while simultaneously reading the motion status of the large-aperture microwave parabolic antenna load.

[0079] In a further specific embodiment, the BeiDou inertial navigation acquisition module performs attitude fusion processing on the antenna attitude sampling sequence. The attitude fusion processing first determines the initial attitude of the antenna load end based on the heading data and attitude angle data. Specifically, the heading data is used to determine the basic direction of the antenna load end relative to the geographic north, and the attitude angle data is used to determine the current attitude state of the antenna load end in the azimuth, pitch, and roll directions. The two are mapped to the same sampling time to form the initial attitude. The initial attitude is used as the starting attitude state for subsequent continuous recursion.

[0080] After determining the initial attitude, the BeiDou inertial navigation acquisition module continuously recursively calculates the initial attitude based on the angular velocity data. The continuous recursion refers to determining the azimuth attitude change, pitch attitude change, and roll attitude change that occur at the antenna load end within the time interval according to the sampling time sequence in the antenna attitude sampling sequence and the angular velocity change between two adjacent sampling times. These changes are then accumulated into the attitude state of the previous sampling time to obtain the recursive attitude at the current sampling time.

[0081] By continuously iterating, it is possible to maintain continuous tracking of rapid attitude changes at the antenna load even when the update interval of BeiDou positioning data and heading data is long.

[0082] Because the inertial measurement unit may accumulate drift during continuous recursion, the BeiDou inertial navigation acquisition module further corrects the attitude drift after recursion based on acceleration data, specifically including:

[0083] The BeiDou inertial navigation acquisition module determines the gravity direction response and motion acceleration change of the antenna load at the current sampling time based on acceleration data. When there is a continuous deviation between the recursive attitude and the attitude trend reflected by the acceleration data, the recursive attitude is corrected to make the corrected attitude consistent with the actual motion trend of the antenna load. The drift correction is based on the correspondence between acceleration data and recursive attitude to suppress the cumulative error caused by continuous angular velocity recursion.

[0084] After drift correction is completed, the BeiDou inertial navigation acquisition module performs Kalman filtering and complementary filtering on the corrected attitude. Kalman filtering is used to smooth the corrected attitude based on the continuity of attitude changes between consecutive sampling times and to suppress the influence of sudden noise on the attitude results.

[0085] Complementary filtering is used to fuse the responsiveness of angular velocity data to rapid attitude changes with the constraint of acceleration and attitude angle data on long-term attitude stability, so that the attitude results can reflect the dynamic changes caused by the swaying of the offshore platform and reduce the long-term deviation caused by inertial measurement drift.

[0086] After the attitude fusion processing described above, the BeiDou inertial navigation acquisition module generates antenna attitude observation data. The antenna attitude observation data includes azimuth attitude, pitch attitude, roll attitude, corresponding attitude change rate, and low-frequency swaying trend extracted from the attitude change rate. The azimuth attitude is used to characterize the current attitude of the large-aperture microwave parabolic antenna in the horizontal pointing direction; the pitch attitude is used to characterize the current attitude of the large-aperture microwave parabolic antenna in the pitch direction; and the roll attitude is used to characterize the current attitude of the large-aperture microwave parabolic antenna in the lateral tilt direction.

[0087] The attitude change rate refers to the rate at which the azimuth attitude, pitch attitude, and roll attitude change between adjacent sampling times, and is determined by the BeiDou inertial navigation acquisition module based on the attitude change process obtained from continuous sampling.

[0088] The low-frequency swaying trend is extracted from the attitude change rate. Specifically, the Beidou inertial navigation acquisition module reads the attitude change rate at multiple consecutive sampling times, identifies the attitude change part with a longer duration and a periodic or slow reciprocating direction, and takes this part as the low-frequency swaying trend.

[0089] For attitude changes that are short in duration, abrupt in amplitude, and do not have continuous reciprocating characteristics, they are suppressed as high-frequency disturbances or transient interferences and are not output as low-frequency swaying trend changes. The resulting low-frequency swaying trend changes can reflect the impact of low-frequency swaying of the offshore platform caused by sea waves on the attitude of the antenna load end.

[0090] The target pointing calculation module is used to generate a microwave link target pointing reference based on the location of the local offshore platform, the location of the remote communication station, the antenna installation reference angle, microwave link parameters, and the actual three-axis rotation angle position, and to calculate the attitude deviation of the antenna relative to the microwave link target pointing reference. Specific implementation details include:

[0091] The target pointing calculation module generates a microwave link target pointing reference based on the location of the local offshore platform, the location of the remote communication station, the antenna installation reference angle, microwave link parameters, and the actual rotation angle of the three axes, and further calculates the attitude deviation of the large-aperture microwave parabolic antenna relative to the microwave link target pointing reference.

[0092] The target pointing calculation module receives the local offshore platform position output by the Beidou inertial navigation acquisition module and reads the pre-configured peer communication station position. The local offshore platform position is used to characterize the position of the offshore platform where the large-aperture microwave parabolic antenna is located in the geographic coordinate system. The peer communication station position is used to characterize the position of the shore-based communication station, the adjacent offshore platform communication station, or other peer microwave communication equipment in the geographic coordinate system.

[0093] In this embodiment, the geographic coordinate system is a coordinate description method that uses geographic north, geographic east, and vertical as directional references, and is used to uniformly describe the location of the local offshore platform and the location of the remote communication station.

[0094] The target pointing calculation module first determines the spatial pointing direction of the microwave communication link based on the location of the local offshore platform and the location of the remote communication station. Specifically, the target pointing calculation module uses the location of the local offshore platform as the link start point and the location of the remote communication station as the link end point to determine the spatial direction relationship from the local offshore platform to the remote communication station.

[0095] Spatial directional relationships include horizontal pointing relationships and vertical elevation relationships. Horizontal pointing relationships are used to determine the target's azimuth and direction, while vertical elevation relationships are used to determine the target's pitch and direction.

[0096] The microwave link parameters are parameters related to establishing a communication link with a large-aperture microwave parabolic antenna, and may include one or more of the following: antenna beamwidth, link allowable pointing error, polarization direction requirement, link operating frequency band, height information of the peer communication station, and installation height correction information.

[0097] Microwave link parameters are used to constrain the generation of microwave link target pointing reference and the judgment of attitude deviation. For example, when the microwave link parameters are configured with the link allowable pointing error, the target pointing calculation module can use the link allowable pointing error as the reference boundary for subsequent judgment of whether the azimuth deviation and pitch deviation need to be compensated.

[0098] When the microwave link parameters are configured with polarization direction requirements, the target pointing calculation module can use the polarization direction requirements as one of the bases for determining the attitude maintenance reference.

[0099] The antenna installation reference angle is used to characterize the fixed angular relationship between the antenna's own null position and the installation reference direction of the offshore platform after the large-aperture microwave parabolic antenna is installed. The antenna installation reference angle can be determined during the installation and commissioning stage. Specifically, it can be determined by aligning the large-aperture microwave parabolic antenna with the communication station at the opposite end in a known direction, recording the reference positions of the azimuth rotation execution unit, pitch compensation execution unit, and roll compensation execution unit at this time, and saving the angular relationship between the reference position and the installation direction of the offshore platform as the antenna installation reference angle.

[0100] The antenna installation reference angle is used to eliminate the fixed deviation between the actual installation direction and the theoretical installation direction of the antenna, and to prevent the target pointing calculation module from performing calculations only according to the theoretical installation position.

[0101] The actual rotation angles of the three axes consist of the actual azimuth angle, the actual pitch angle, and the actual roll angle, specifically including:

[0102] The actual azimuth angle is used to characterize the horizontal angle position that the azimuth rotation execution unit has currently executed, the actual pitch angle is used to characterize the pitch compensation execution unit has currently executed, and the actual roll angle is used to characterize the lateral attitude angle position that the roll compensation execution unit has currently executed.

[0103] The target pointing calculation module establishes the attitude transformation relationship between the antenna installation coordinate system and the geographic coordinate system based on the antenna installation reference angle and the actual rotation angle position of the three axes.

[0104] The antenna installation coordinate system is a coordinate description method established with reference to the installation state of a large-aperture microwave parabolic antenna. It is used to describe the antenna's own azimuth, elevation, and lateral attitude.

[0105] When the target pointing calculation module establishes the attitude transformation relationship, it first reads the antenna installation reference angle to determine the fixed offset of the antenna installation coordinate system relative to the installation reference direction of the offshore platform, and then reads the actual rotation angle position of the three axes to determine the real-time attitude change caused by the azimuth rotation execution unit, pitch compensation execution unit and roll compensation execution unit at the current moment.

[0106] Then, the fixed offset and real-time attitude changes are sequentially matched in the three directions of azimuth, pitch, and roll to form the attitude transformation relationship between the antenna installation coordinate system and the geographic coordinate system.

[0107] After obtaining the attitude transformation relationship, the target pointing calculation module transforms the spatial pointing direction of the microwave communication link to the antenna installation coordinate system, and generates the microwave link target pointing reference.

[0108] The microwave link target pointing reference includes the target azimuth direction and the target elevation direction. The target azimuth direction is used to characterize the horizontal target direction that the large-aperture microwave parabolic antenna should point to in the antenna installation coordinate system.

[0109] The target elevation direction is used to characterize the elevation target direction that a large-aperture microwave parabolic antenna should point to in the antenna mounting coordinate system.

[0110] By converting the spatial pointing direction to the antenna installation coordinate system, the azimuth calibration command and the pitch calibration command can be directly mapped to the actual execution direction of the antenna load adjustment module.

[0111] In a further specific embodiment, the target pointing calculation module is also used to generate attitude deviation based on the antenna attitude observation data and the microwave link target pointing reference. The antenna attitude observation data is generated by the Beidou inertial navigation acquisition module and includes at least azimuth attitude, pitch attitude, roll attitude and corresponding attitude change rate.

[0112] The azimuth attitude is used to characterize the actual attitude of the large-aperture microwave parabolic antenna in the horizontal pointing direction, the pitch attitude is used to characterize the actual attitude of the large-aperture microwave parabolic antenna in the pitch direction, and the roll attitude is used to characterize the actual attitude of the large-aperture microwave parabolic antenna in the lateral tilt direction.

[0113] The target pointing calculation module compares the azimuth attitude in the antenna attitude observation data with the target azimuth direction to obtain the azimuth deviation, which is used to characterize the amount of deviation of the antenna's horizontal pointing relative to the target azimuth direction.

[0114] When the azimuth attitude is on one side of the target azimuth direction, the azimuth deviation is used to indicate that the azimuth rotation execution unit needs to be corrected in the opposite direction; when the azimuth attitude is consistent with the target azimuth direction or is within the allowable pointing error range, the azimuth deviation can be determined as not needing to continue to increase azimuth compensation.

[0115] The target pointing calculation module compares the pitch attitude in the antenna attitude observation data with the target pitch direction to obtain the pitch deviation;

[0116] The pitch deviation is used to characterize the amount of deviation of the antenna pitch direction relative to the target pitch direction;

[0117] When the pitch attitude is manifested as the antenna aperture tilting up or down relative to the target pitch direction, the pitch deviation is used to instruct the pitch compensation execution unit to generate the corresponding pitch compensation action, so that the antenna pitch direction converges towards the target pitch direction.

[0118] The target pointing calculation module compares the roll attitude in the antenna attitude observation data with the attitude maintenance reference to obtain the roll deviation.

[0119] The attitude maintenance reference is used to characterize the reference state that the large-aperture microwave parabolic antenna should maintain in the lateral attitude direction. It can be determined by antenna polarization direction calibration during the installation and commissioning stage, or it can be determined according to the polarization direction requirements in the microwave link parameters.

[0120] For microwave communication links that are sensitive to polarization direction, deviations in the roll attitude will cause changes in the antenna polarization attitude. Therefore, the target pointing calculation module compares the roll attitude with the attitude maintenance reference to obtain the roll deviation. The roll deviation is used to characterize the amount of deviation of the antenna polarization attitude from the attitude maintenance reference.

[0121] The target pointing calculation module generates attitude deviations based on azimuth deviation, pitch deviation, and roll deviation. These attitude deviations are a three-axis deviation description composed of azimuth deviation, pitch deviation, and roll deviation, used to simultaneously characterize the deviation of the large-aperture microwave parabolic antenna in three directions: horizontal pointing, pitch pointing, and polarization attitude. When generating attitude deviations, the target pointing calculation module associates the azimuth deviation, pitch deviation, and roll deviation with the same sampling time, enabling the three-axis active compensation module to read the deviation in three directions under the same time reference and generate azimuth calibration commands, pitch calibration commands, and roll calibration commands respectively.

[0122] During operation, the target pointing calculation module continuously updates the attitude deviation according to the sampling time of the antenna attitude observation data;

[0123] When the attitude of the offshore platform changes due to waves, wind loads or platform vibration, the azimuth attitude, pitch attitude and roll attitude output by the Beidou inertial navigation acquisition module will change accordingly.

[0124] The target pointing calculation module regenerates the azimuth deviation, pitch deviation, and roll deviation based on the updated antenna attitude observation data, the actual three-axis rotation position, and the microwave link target pointing reference.

[0125] Through the above implementation method, the target pointing calculation module can convert the spatial pointing direction formed by the position of the local offshore platform and the position of the remote communication station into a microwave link target pointing reference in the antenna installation coordinate system by combining the antenna installation reference angle and the actual three-axis rotation position. It can also compare the azimuth attitude, pitch attitude and roll attitude in the antenna attitude observation data with the target azimuth direction, target elevation direction and attitude maintenance reference, respectively, and generate an attitude deviation composed of azimuth deviation, pitch deviation and roll deviation. This allows the three-axis active compensation module to mechanically compensate the overall pointing of the large-aperture microwave parabolic antenna based on the attitude deviation.

[0126] The three-axis active compensation module generates azimuth, pitch, and roll calibration commands based on attitude deviations, and drives the corresponding azimuth rotation, pitch compensation, and roll compensation mechanisms to perform reverse compensation, ensuring the antenna maintains target pointing. Specific implementation details include:

[0127] In one specific embodiment, the three-axis active compensation module is used to generate azimuth calibration commands, pitch calibration commands, and roll calibration commands based on the attitude deviation output by the target pointing calculation module. It then drives the corresponding mechanisms to perform reverse compensation through the azimuth rotation execution unit, pitch compensation execution unit, and roll compensation execution unit, so that the large-aperture microwave parabolic antenna maintains the target pointing during the swaying of the offshore platform. The three-axis active compensation module includes an attitude outer loop control unit, an angular velocity inner loop control unit, and a feedforward compensation unit.

[0128] The attitude outer loop control unit is used to generate attitude convergence control quantities based on attitude deviations. The attitude deviations consist of azimuth deviation, pitch deviation, and roll deviation. The azimuth deviation represents the deviation of the antenna's horizontal pointing direction from the target azimuth direction, the pitch deviation represents the deviation of the antenna's pitch pointing direction from the target pitch direction, and the roll deviation represents the deviation of the antenna's polarization attitude from the attitude maintenance reference.

[0129] The attitude outer ring control unit reads the azimuth deviation, pitch deviation and roll deviation respectively, and determines the direction and degree of deviation of each deviation relative to the corresponding target direction;

[0130] When the deviation in a certain direction indicates that the antenna attitude is deviating from the target state, the attitude outer loop control unit generates a control quantity that brings the attitude in that direction toward the target state.

[0131] When the deviation in a certain direction has entered the allowable deviation range, the attitude outer loop control unit reduces the convergence control output in that direction to prevent the antenna from repeatedly swinging near the target.

[0132] The attitude convergence control includes azimuth convergence components, pitch convergence components, and roll convergence components. The azimuth convergence component is used to determine the trend of the antenna horizontal pointing towards the target azimuth direction; the pitch convergence component is used to determine the trend of the antenna pitch pointing towards the target pitch direction; and the roll convergence component is used to determine the trend of the antenna polarization attitude towards maintaining the attitude reference.

[0133] When generating attitude convergence control quantities, the attitude outer loop control unit determines the compensation direction based on the direction of the attitude deviation, determines the required degree of convergence based on the magnitude of the attitude deviation, and limits the convergence amplitude in combination with the allowable deviation range, so that the three-axis active compensation module prioritizes eliminating attitude deviations that have a significant impact on the target pointing.

[0134] The angular velocity inner loop control unit is used to generate disturbance suppression control quantity based on the attitude change rate in the antenna attitude observation data, wherein the attitude change rate is used to characterize the rate of change of azimuth attitude, pitch attitude and roll attitude between adjacent sampling times.

[0135] The inner loop control unit of angular velocity reads the azimuth attitude change rate, pitch attitude change rate and roll attitude change rate respectively, and determines whether the antenna load end has a tendency to continue to deviate from the target state in the three directions.

[0136] When the attitude change rate indicates that the antenna is rapidly moving away from the target, the angular velocity inner loop control unit improves the disturbance suppression effect in the corresponding direction, enabling the corresponding execution unit to counteract the attitude change in that direction more quickly.

[0137] When the attitude change rate indicates that the antenna is approaching the target, the inner loop control unit of angular velocity reduces the response intensity in the corresponding direction, so that the antenna attitude converges smoothly when approaching the target.

[0138] The disturbance suppression control quantities include azimuth disturbance suppression components, pitch disturbance suppression components, and roll disturbance suppression components. The azimuth disturbance suppression component is used to suppress rapid swaying in the horizontal direction, the pitch disturbance suppression component is used to suppress rapid undulation in the pitch direction, and the roll disturbance suppression component is used to suppress rapid tilting in the lateral attitude direction. Unlike the attitude convergence control quantity, which is mainly used to eliminate existing attitude deviations, the disturbance suppression control quantity is mainly used to suppress the trend of attitude deviations continuing to expand, thereby improving the response speed of the three-axis active compensation module to the swaying of the offshore platform.

[0139] The feedforward compensation unit is used to generate wave feedforward compensation based on the low-frequency swaying change trend in the antenna attitude observation data. The low-frequency swaying change trend is extracted by the Beidou inertial navigation acquisition module based on the attitude change rate and is used to characterize the continuous, periodic or slow reciprocating attitude changes caused by the waves.

[0140] After reading the low-frequency shaking trend, the feedforward compensation unit determines the direction of the upcoming attitude change in the three directions of azimuth, pitch, and roll.

[0141] When the low-frequency swaying trend indicates that the antenna load will continue to shift in a certain direction, the feedforward compensation unit generates a compensation amount opposite to the expected shift direction in advance.

[0142] When the trend of low-frequency undulation is discontinuous or the direction of change is unstable, the feedforward compensation unit reduces or suspends the wave feedforward compensation in the corresponding direction to avoid misjudging instantaneous disturbances as low-frequency wave undulations.

[0143] The wave feedforward compensation includes an azimuth feedforward compensation component, a pitch feedforward compensation component, and a roll feedforward compensation component. The azimuth feedforward compensation component is used to offset the azimuth shift caused by waves in advance in the horizontal direction; the pitch feedforward compensation component is used to offset the pitch change trend caused by waves in advance in the pitch direction; and the roll feedforward compensation component is used to offset the roll change trend caused by waves in advance in the lateral attitude direction.

[0144] The wave feedforward compensation is generated in advance based on the low-frequency swaying trend, thereby reducing the impact of periodic wave swaying on the antenna target pointing.

[0145] When generating calibration commands, the three-axis active compensation module first determines the three-axis target compensation direction according to the attitude convergence control quantity. Specifically, when the azimuth deviation indicates that the antenna's horizontal pointing direction deviates from the target azimuth direction, the three-axis active compensation module determines the azimuth target compensation direction opposite to the azimuth deviation.

[0146] When the pitch deviation indicates that the antenna pitch direction deviates from the target pitch direction, the three-axis active compensation module determines the pitch target compensation direction opposite to the pitch deviation;

[0147] When the roll deviation indicates that the antenna polarization attitude has deviated from the attitude maintenance reference, the three-axis active compensation module determines the roll target compensation direction opposite to the roll deviation. This forms the three-axis target compensation direction.

[0148] Subsequently, the three-axis active compensation module determines the three-axis compensation response speed according to the disturbance suppression control amount. The three-axis compensation response speed is used to limit the response speed of the azimuth rotation execution unit, the pitch compensation execution unit, and the roll compensation execution unit when performing compensation actions.

[0149] The three-axis active compensation module determines the compensation response speed in the azimuth direction based on the azimuth disturbance suppression component, the compensation response speed in the pitch direction based on the pitch disturbance suppression component, and the compensation response speed in the roll direction based on the roll disturbance suppression component.

[0150] When the rate of attitude change is large and the direction is continuous, the compensation response speed in the corresponding direction increases.

[0151] When the rate of attitude change decreases or approaches the target state, the compensation response speed in the corresponding direction decreases to reduce overshoot and repeated adjustments.

[0152] After determining the three-axis target compensation direction and the three-axis compensation response speed, the three-axis active compensation module makes an advance correction to the three-axis target compensation direction according to the wave feedforward compensation amount. The advance correction means that before generating the final calibration command, the expected attitude offset corresponding to the low-frequency swaying change trend is included in the compensation action, so that the execution unit starts to compensate in the opposite direction before the attitude offset caused by the waves is fully formed.

[0153] For example, when the low-frequency swaying trend indicates that the pitch posture will continue to change in the upward direction, the three-axis active compensation module adds the downward pitch correction content in advance to the pitch calibration command;

[0154] When the low-frequency swaying trend indicates that the roll attitude will continue to tilt to one side, the three-axis active compensation module adds a correction to the opposite side to straighten the position in advance in the roll calibration command.

[0155] Before generating the azimuth calibration command, pitch calibration command, and roll calibration command, the three-axis active compensation module also performs execution boundary checks on the three-axis target compensation direction and three-axis compensation response speed based on the allowable rotation angle range, allowable response speed, allowable compensation amplitude of the azimuth rotation execution unit, pitch compensation execution unit, and roll compensation execution unit, as well as the current actual rotation angle position of the three axes.

[0156] If the target compensation action in a certain direction does not exceed the allowable rotation angle range and allowable response speed of the corresponding execution unit, the three-axis active compensation module generates the corresponding calibration command according to the target compensation action;

[0157] If the target compensation action in a certain direction exceeds the allowable angle range, the corresponding calibration command will be restricted to the allowable angle range.

[0158] If the compensation response speed in a certain direction exceeds the allowable response speed, the corresponding compensation response speed will be reduced before generating the calibration command.

[0159] By performing the above boundary checks, mechanical shocks, attitude overshoots, or repeated adjustments caused by excessive compensation or overly rapid response of the azimuth rotation mechanism, pitch compensation mechanism, and roll compensation mechanism can be avoided.

[0160] After the above processing, the three-axis active compensation module generates azimuth calibration command, pitch calibration command and roll calibration command. The azimuth calibration command includes the azimuth target compensation direction and azimuth compensation response speed, which are used to drive the azimuth rotation execution unit to drive the azimuth rotation mechanism to perform the horizontal reverse compensation action.

[0161] The pitch calibration command includes the pitch target compensation direction and pitch compensation response speed, which are used to drive the pitch compensation execution unit to perform the pitch compensation mechanism to perform the reverse compensation action in the pitch direction;

[0162] The roll calibration command includes the roll target compensation direction and roll compensation response speed, which are used to drive the roll compensation execution unit to perform a reverse compensation action in the lateral attitude direction.

[0163] The reverse compensation refers to the fact that the direction of action of the azimuth rotation mechanism, the pitch compensation mechanism and the roll compensation mechanism is opposite to the direction of deviation of the corresponding attitude deviation. Specifically, when the azimuth deviation indicates that the antenna is pointing horizontally toward one side of the target azimuth direction, the azimuth rotation mechanism adjusts to the opposite side.

[0164] When the pitch deviation indicates that the antenna pitch is higher or lower than the target pitch direction, the pitch compensation mechanism adjusts to bring the antenna pitch back to the target pitch direction;

[0165] When the roll deviation indicates that the antenna polarization attitude has tilted to one side relative to the attitude maintenance reference, the roll compensation mechanism adjusts to the opposite side.

[0166] Through the reverse compensation process, the overall antenna pointing gradually returns to the target state corresponding to the microwave link target pointing reference.

[0167] During continuous operation, the three-axis active compensation module continuously receives attitude deviation, attitude change rate and low-frequency swaying trend according to the sampling time, and continuously updates attitude convergence control, disturbance suppression control and wave feedforward compensation.

[0168] After receiving the corresponding calibration command, the azimuth rotation execution unit, the pitch compensation execution unit, and the roll compensation execution unit respectively drive the azimuth rotation mechanism, the pitch compensation mechanism, and the roll compensation mechanism to perform compensation actions.

[0169] The three-axis angle feedback component then feeds back the new actual three-axis rotation position. The target pointing calculation module updates the attitude deviation based on the new actual three-axis rotation position, and the three-axis active compensation module continues to generate calibration instructions based on the updated attitude deviation.

[0170] This forms a control process that includes attitude deviation generation, three-axis active compensation, and angle feedback updates, enabling the large-aperture microwave parabolic antenna to maintain target pointing under the swaying conditions of a sea platform.

[0171] The link feedback correction module is used to collect microwave communication link quality data and correct the control parameters of the microwave link target pointing reference, antenna installation reference angle, and three-axis active compensation module. Specific implementation details include:

[0172] The link feedback correction module collects microwave communication link quality data and judges the link quality change status after attitude compensation based on the corresponding change relationship between microwave communication link quality data and attitude deviation.

[0173] When the link quality is judged to be degraded, the link feedback correction module corrects the control parameters of the microwave link target pointing reference, the antenna installation reference angle, and the three-axis active compensation module, so that the attitude calibration results of the large-aperture microwave parabolic antenna meet the attitude deviation convergence requirements and the microwave communication link stability requirements.

[0174] Microwave communication link quality data is output by the local microwave communication equipment, modem, or link monitoring unit, and includes at least one of the following: received signal strength, signal-to-noise ratio, bit error rate, packet loss rate, and link interruption flag.

[0175] The received signal strength is used to characterize the strength of the microwave signal received from the other end at this end;

[0176] Signal-to-noise ratio (SNR) is used to characterize the quality of an effective signal relative to noise.

[0177] Bit error rate is used to characterize the degree to which erroneous bits occur during data transmission;

[0178] Packet loss rate is used to characterize the degree of data packet loss during transmission;

[0179] Link interruption flags are used to indicate whether a microwave communication link is in a state of continuous unavailability.

[0180] The above data can be read by the management interface, network management interface, or status output interface of the microwave communication equipment according to the set sampling period.

[0181] When collecting microwave communication link quality data, the link feedback correction module binds the microwave communication link quality data with the corresponding sampling time and performs time correspondence with the attitude deviation output by the target pointing calculation module; the attitude deviation includes azimuth deviation, pitch deviation and roll deviation.

[0182] The link feedback correction module records the microwave communication link quality data, azimuth deviation, pitch deviation, roll deviation, and the azimuth calibration command, pitch calibration command, and roll calibration command output by the three-axis active compensation module at the same sampling time or within the same feedback observation window, according to the same time reference.

[0183] The feedback observation window refers to a continuous period of time used to observe the changes in link quality before and after attitude compensation. Its length can be determined based on the microwave communication equipment status update cycle and the response time of the three-axis active compensation module, ensuring that the impact of an attitude compensation action on link quality can be observed within this window.

[0184] The link feedback correction module determines the link quality change status after attitude compensation based on the corresponding change relationship between microwave communication link quality data and attitude deviation. Specifically, before the three-axis active compensation module performs the compensation action, the link feedback correction module records the received signal strength, signal-to-noise ratio, bit error rate, packet loss rate and link interruption flag in the current feedback observation window, and uses it as the link quality status before compensation.

[0185] After the three-axis active compensation module performs the compensation action, the link feedback correction module continues to record the microwave communication link quality data in the next feedback observation window, and uses it as the link quality status after compensation.

[0186] The link feedback correction module compares the link quality state before compensation with the link quality state after compensation. When the received signal strength and signal-to-noise ratio remain stable or improve, and the bit error rate, packet loss rate, and link interruption flag do not increase, it is determined that the link quality after attitude compensation is in a stable or improved state.

[0187] When the received signal strength or signal-to-noise ratio continues to decrease, or the bit error rate or packet loss rate continues to increase, or the link interruption flag is triggered, it is determined that the link quality after attitude compensation has deteriorated.

[0188] It should be noted that before performing correction, the link feedback correction module also determines whether the link quality degradation meets the correction activation conditions. The correction activation conditions include: the link quality degradation continues for more than one feedback observation window, or at least one of the received signal strength, signal-to-noise ratio, bit error rate, packet loss rate, and link interruption flag continuously shows a deterioration trend, and the deterioration trend corresponds to the changes in azimuth deviation, pitch deviation, or roll deviation in time. When the link quality degradation only occurs at a single sampling moment, and the sampling moment returns to normal, the link feedback correction module does not immediately correct the control parameters of the microwave link target pointing reference, antenna installation reference angle, or three-axis active compensation module, but continues to observe the next feedback observation window.

[0189] After determining that the link quality has deteriorated, the link feedback correction module further determines the correction target by combining the changes in attitude deviation;

[0190] When the attitude deviation has been reduced, but the received signal strength and signal-to-noise ratio still decrease, or the bit error rate and packet loss rate still increase, it indicates that the three-axis active compensation module has brought the antenna attitude toward the current microwave link target pointing reference, but the microwave link target pointing reference or the antenna installation reference angle may be offset.

[0191] At this point, the link feedback correction module prioritizes correcting the microwave link target pointing reference or antenna installation reference angle, so that the target azimuth direction, target elevation direction and attitude maintenance reference subsequently generated by the target pointing solution module are closer to the actual optimal link quality position.

[0192] Specifically, the link feedback correction module determines which direction the link quality degradation is related to the compensation action based on the direction of change in azimuth, pitch, and roll deviations before and after the link quality degradation. This includes:

[0193] If the link quality decreases after the antenna completes compensation in the azimuth direction, but the pitch and roll deviations change little, the link feedback correction module will make a small correction to the target azimuth direction in the microwave link target pointing reference, or correct the azimuth reference relationship in the antenna installation reference angle.

[0194] If the link quality deteriorates after the antenna completes compensation in the pitch direction, the link feedback correction module will make a small correction to the target elevation direction in the microwave link target pointing reference, or correct the elevation reference relationship in the antenna installation reference angle.

[0195] If the link quality deteriorates after roll compensation, and the link quality data shows changes related to polarization attitude, the link feedback correction module corrects the roll reference relationship in the attitude maintenance reference or antenna installation reference angle.

[0196] When the attitude deviation fails to be effectively reduced and the link quality deteriorates, it indicates that the control response of the three-axis active compensation module may be insufficient, too fast, or there may be a lag in the compensation direction. In this case, the link feedback correction module corrects the control parameters of the three-axis active compensation module. The control parameters include the generation parameters of the attitude convergence control quantity, the generation parameters of the disturbance suppression control quantity, the generation parameters of the wave feedforward compensation quantity, the three-axis compensation response speed limit parameters, and the compensation amplitude limit parameters.

[0197] The link feedback correction module determines the correction direction based on changes in attitude deviation and link quality:

[0198] When attitude deviation converges slowly and is accompanied by a decline in link quality, improve the compensation response capability in the corresponding direction.

[0199] When the attitude deviation changes repeatedly near the target and is accompanied by fluctuations in link quality, reduce the compensation response speed or compensation magnitude in the corresponding direction.

[0200] When the trend of low-frequency sway changes has a continuous correlation with the decline in link quality, the degree of advance action of the wave feedforward compensation is adjusted to make the feedforward compensation more in line with the actual attitude changes caused by the waves.

[0201] When correcting the microwave link target pointing reference, the link feedback correction module does not directly replace the original target azimuth and elevation directions, but makes gradual adjustments based on the original microwave link target pointing reference.

[0202] The incremental adjustment refers to making a limited correction to the target azimuth or pitch direction each time based only on the deviation direction reflected by the link quality change within the current feedback observation window, and continuing to verify the correction results in the next feedback observation window.

[0203] When the received signal strength and signal-to-noise ratio recover after correction, the bit error rate and packet loss rate decrease, and the link interruption flag is not triggered, the link feedback correction module retains the correction result;

[0204] If the link quality continues to decline after correction, the link feedback correction module withdraws or reverses the correction result to avoid deviation of the target from the baseline due to a single abnormal feedback.

[0205] When correcting the antenna installation reference angle, the link feedback correction module treats the antenna installation reference angle as a slowly varying parameter. The slowly varying parameter refers to a parameter that does not change immediately due to a single sampling moment or a single instantaneous link quality fluctuation, but is corrected only when it shows the same directional offset in multiple feedback observation windows. For example, if the target pointing solution module continuously generates small attitude deviations, but the link quality always improves after adjustment in a certain azimuth or pitch direction, it indicates that the actual installation null position of the large-aperture microwave parabolic antenna may differ from the recorded antenna installation reference angle.

[0206] At this point, the link feedback correction module corrects the antenna installation reference angle based on the link quality improvement direction observed in the multiple feedback observation windows, enabling the subsequent target pointing calculation module to generate a microwave link target pointing reference on a more accurate installation reference basis.

[0207] When correcting the control parameters of the three-axis active compensation module, the link feedback correction module associates the link quality change results with the corresponding azimuth calibration command, pitch calibration command and roll calibration command;

[0208] If the attitude deviation decreases and the link quality improves after a calibration command is output in a certain direction, the link feedback correction module maintains the control parameters for that direction.

[0209] If the attitude deviation decreases but the link quality deteriorates after the calibration command is output in a certain direction, the link feedback correction module reduces the compensation magnitude in that direction or adjusts the corresponding target pointing reference.

[0210] If the attitude deviation does not decrease and the link quality deteriorates after the calibration command is output in a certain direction, the link feedback correction module improves the compensation response capability in that direction or corrects the degree of advance effect of the wave feedforward compensation.

[0211] Through the above processing, the control parameters of the three-axis active compensation module can be adapted according to the feedback from the actual communication link.

[0212] In actual operation, the link feedback correction module continuously receives microwave communication link quality data and continuously reads the attitude deviation output by the target pointing solution module.

[0213] When the antenna attitude changes due to wind and waves on the offshore platform, the three-axis active compensation module first performs reverse compensation based on the attitude deviation; the link feedback correction module then judges whether the compensation result is conducive to link stability based on the microwave communication link quality data before and after compensation.

[0214] If the link quality is stable or improved after compensation, the current microwave link target pointing reference, antenna installation reference angle and control parameters of the three-axis active compensation module will continue to be used;

[0215] If the link quality deteriorates after compensation, the control parameters of the microwave link target pointing reference, antenna installation reference angle, and three-axis active compensation module are corrected according to the above logic, and the corrected results are fed back to the target pointing calculation module and the three-axis active compensation module for use in the next attitude deviation calculation and calibration command generation.

[0216] Through the above implementation method, the link feedback correction module can establish a time correspondence between microwave communication link quality data such as received signal strength, signal-to-noise ratio, bit error rate, packet loss rate and link interruption marker, and azimuth deviation, pitch deviation and roll deviation, and judge whether attitude calibration has truly improved the communication link based on the link quality change status before and after attitude compensation.

[0217] When the link quality deteriorates, the link feedback correction module can correct the microwave link target pointing reference, antenna mounting reference angle and control parameters of the three-axis active compensation module for target pointing offset, installation reference offset or control response mismatch, respectively, so that the large-aperture microwave parabolic antenna can maintain more stable target pointing and microwave communication link quality in the swaying environment of the offshore platform.

[0218] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0219] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0220] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0221] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0222] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sea-based microwave antenna attitude calibration system fusing Beidou inertial navigation, characterized in that: It includes an antenna load adjustment module, a BeiDou inertial navigation acquisition module, a target pointing calculation module, a three-axis active compensation module, and a link feedback correction module; The antenna support adjustment module is used to support the large-aperture microwave parabolic antenna and to mechanically adjust the overall pointing of the antenna through an azimuth rotation mechanism, a pitch compensation mechanism, and a roll compensation mechanism. The BeiDou inertial navigation acquisition module is used to collect BeiDou positioning data, heading data, angular velocity data, acceleration data, and attitude angle data from the local marine platform, and generate antenna attitude observation data. The target pointing calculation module is used to generate a microwave link target pointing reference based on the location of the local offshore platform, the location of the remote communication station, the antenna installation reference angle, microwave link parameters, and the actual rotation angle of the three axes, and to calculate the attitude deviation of the antenna relative to the microwave link target pointing reference. The three-axis active compensation module is used to generate azimuth calibration commands, pitch calibration commands and roll calibration commands based on attitude deviations, and drive the corresponding azimuth rotation mechanism, pitch compensation mechanism and roll compensation mechanism to perform reverse compensation so that the antenna keeps the target pointing. The link feedback correction module is used to collect microwave communication link quality data and correct the control parameters of the microwave link target pointing reference, antenna installation reference angle, and three-axis active compensation module.

2. The system according to claim 1, wherein the system is characterized in that: The antenna load adjustment module includes an azimuth rotation execution unit, a pitch compensation execution unit, a roll compensation execution unit, and an antenna load platform; The azimuth rotation execution unit includes an azimuth rotation mechanism, the pitch compensation execution unit includes a pitch compensation mechanism, and the roll compensation execution unit includes a roll compensation mechanism. A large-aperture microwave parabolic antenna is mounted on the antenna load platform. The azimuth rotation execution unit is used to receive azimuth calibration commands and adjust the overall azimuth angle of the antenna. The pitch compensation execution unit is used to receive pitch calibration commands and adjust the pitch attitude of the antenna. The roll compensation execution unit is used to receive roll calibration commands and adjust the lateral attitude of the antenna, so that the antenna load adjustment module forms a controllable attitude adjustment channel in three directions: azimuth, pitch and roll.

3. The system according to claim 2, wherein the system is a sea-based microwave antenna attitude calibration system. The antenna load adjustment module also includes a three-axis angle feedback component, which collects the actual rotation angle positions of the azimuth rotation execution unit, the pitch compensation execution unit and the roll compensation execution unit respectively, and generates the actual azimuth rotation angle, the actual pitch rotation angle and the actual roll rotation angle; The target pointing calculation module uses the actual azimuth angle, actual pitch angle, and actual roll angle as the actual three-axis angle positions to correct the microwave link target pointing reference and attitude deviation.

4. The system according to claim 2, wherein the system is a sea-based microwave antenna attitude calibration system. The BeiDou inertial navigation acquisition module includes a BeiDou receiving unit, an inertial measurement unit, and a time synchronization unit; The Beidou receiving unit is used to collect Beidou positioning data and heading data of the local offshore platform. The inertial measurement unit is rigidly installed on the antenna load platform of the antenna load adjustment module and is used to directly collect angular velocity data, acceleration data and attitude angle data of the large-aperture microwave parabolic antenna load end. The time synchronization unit is used to time-mark and align the sampling times of BeiDou positioning data, heading data, angular velocity data, acceleration data, and attitude angle data to form an antenna attitude sampling sequence with a unified time reference.

5. The system according to claim 4, wherein the system is a sea-based microwave antenna attitude calibration system. The BeiDou inertial navigation acquisition module performs attitude fusion processing on the antenna attitude sampling sequence, the attitude fusion processing including: The initial attitude of the antenna load is determined based on the heading data and attitude angle data. The initial attitude is continuously recursively derived based on the angular velocity data. The drift correction of the derived attitude is performed based on the acceleration data. The corrected attitude is then processed by Kalman filtering and complementary filtering to generate antenna attitude observation data. Antenna attitude observation data includes azimuth attitude, pitch attitude, roll attitude, corresponding attitude change rate, and low-frequency swaying trend extracted from the attitude change rate.

6. The marine microwave antenna attitude calibration system integrating BeiDou inertial navigation as described in claim 1, characterized in that: The target pointing calculation module determines the spatial pointing direction of the microwave communication link based on the location of the local offshore platform and the location of the remote communication station. It establishes the attitude transformation relationship between the antenna installation coordinate system and the geographic coordinate system based on the antenna installation reference angle and the actual rotation angle of the three axes. The spatial pointing direction is then transformed to the antenna installation coordinate system to generate a microwave link target pointing reference that includes the target azimuth direction and the target elevation direction.

7. The marine microwave antenna attitude calibration system integrating BeiDou inertial navigation as described in claim 6, characterized in that: The target pointing calculation module compares the azimuth attitude in the antenna attitude observation data with the target azimuth direction, compares the pitch attitude with the target pitch direction, and compares the roll attitude with the attitude maintenance reference to obtain the azimuth deviation, pitch deviation, and roll deviation. Attitude deviation is generated based on azimuth deviation, pitch deviation, and roll deviation. Azimuth deviation is used to characterize the deviation of the antenna's horizontal pointing direction from the target's azimuth direction, pitch deviation is used to characterize the deviation of the antenna's pitch pointing direction from the target's pitch direction, and roll deviation is used to characterize the deviation of the antenna's polarization attitude from the attitude maintenance reference.

8. The marine microwave antenna attitude calibration system integrating BeiDou inertial navigation as described in claim 7, characterized in that: The three-axis active compensation module includes an attitude outer loop control unit, an angular velocity inner loop control unit, and a feedforward compensation unit; The attitude outer loop control unit is used to generate attitude convergence control quantity based on attitude deviation, the angular velocity inner loop control unit is used to generate disturbance suppression control quantity based on attitude change rate in antenna attitude observation data, and the feedforward compensation unit is used to generate wave feedforward compensation quantity based on low-frequency swaying trend in antenna attitude observation data.

9. The marine microwave antenna attitude calibration system integrating BeiDou inertial navigation as described in claim 8, characterized in that: The three-axis active compensation module determines the three-axis target compensation direction according to the attitude convergence control quantity, determines the three-axis compensation response speed according to the disturbance suppression control quantity, and makes advance corrections to the three-axis target compensation direction according to the wave feedforward compensation quantity. It generates azimuth calibration commands, pitch calibration commands, and roll calibration commands, and drives the corresponding mechanisms of the azimuth rotation execution unit, pitch compensation execution unit, and roll compensation execution unit to perform compensation actions in the opposite direction to the attitude deviation.

10. The marine microwave antenna attitude calibration system integrating BeiDou inertial navigation as described in claim 1, characterized in that: The microwave communication link quality data collected by the link feedback correction module includes at least one of the following: received signal strength, signal-to-noise ratio, bit error rate, packet loss rate, and link interruption flag. The link feedback correction module determines the link quality change status after attitude compensation based on the corresponding change relationship between microwave communication link quality data and attitude deviation, and corrects the control parameters of microwave link target pointing reference, antenna installation reference angle and three-axis active compensation module when the link quality deteriorates.

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