A darkroom calibration and attitude simulation system for airborne direction finding equipment

Abstract

This invention discloses an anechoic chamber calibration and attitude simulation system for airborne direction finding equipment, belonging to the field of equipment calibration and testing technology. It includes a microwave anechoic chamber, an attitude simulation mechanism, a target simulation mechanism, and a host computer terminal. The microwave anechoic chamber provides the testing environment. The attitude simulation mechanism includes a six-degree-of-freedom robotic arm and an airborne direction finding equipment support platform. By gripping the airborne direction finding equipment and performing precise movements in six degrees of freedom according to a set attitude trajectory, it simulates the flight conditions of the airborne direction finding equipment on a flight platform. The target simulation mechanism includes a target signal source and a support device, used to generate test signals with controllable direction, polarization, and waveform characteristics. The host computer terminal is used to configure and issue test and calibration tasks, while simultaneously monitoring, analyzing, and managing them. This invention completes scenario-level testing and high-precision calibration of the entire equipment testing chain, reducing reliance on actual flight tests and solving the problem of limited degrees of freedom on ground platforms.

Description

Technical Field

[0001] This invention relates to the field of equipment calibration and testing technology, and in particular to an anechoic chamber calibration and attitude simulation system for airborne direction finding equipment. Background Technology

[0002] In the development, finalization, and support of airborne direction-finding equipment, electronic reconnaissance equipment, and other systems, it is usually necessary to test and calibrate their azimuth and pitch measurement accuracy, target pointing error, installation error compensation effect, and overall direction-finding performance as the aircraft attitude changes, under conditions that are as close as possible to the actual combat environment. In existing engineering practice, there are two main common approaches:

[0003] One type relies on actual flight tests, where the direction-finding equipment is installed on an aircraft or other flight platform according to the design. During actual flight, through pre-designed flight courses and target deployments, the platform attitude, target azimuth, and equipment direction-finding results are collected to analyze the direction-finding error characteristics of the equipment under various attitude conditions and generate calibration parameters accordingly. The other type uses simplified ground-based test conditions, such as in an open field or a semi-anechoic / fully anechoic chamber. A single-axis or dual-axis turntable and simple support are used to rotate the direction-finding equipment, along with a fixed or rotatable signal source and target antenna, to measure the equipment output at different pointing angles, thereby obtaining antenna patterns or static calibration data.

[0004] The existing testing and calibration methods for airborne direction finding equipment have the following problems: 1) Over-reliance on flight testing, resulting in high testing costs and significant constraints; 2) Difficulty in precisely and repeatably controlling the flight attitude and target geometry; 3) Limited degrees of freedom of simplified ground test platforms, making it difficult to realistically reproduce airborne installation conditions; 4) Anechoic chamber testing focuses primarily on antenna performance, lacking scenario-level verification for the entire direction finding link. Summary of the Invention

[0005] In view of this, this application provides an airborne direction finding equipment anechoic chamber calibration and attitude simulation system to address the shortcomings of the existing technology.

[0006] The first aspect of this application provides an anechoic chamber calibration and attitude simulation system for airborne direction-finding equipment, comprising:

[0007] Microwave anechoic chamber, attitude simulation mechanism, target simulation mechanism and host computer terminal;

[0008] The microwave anechoic chamber is used to provide a low-reflection, low-interference electromagnetic environment and serves as a reference space for establishing the anechoic chamber coordinate system.

[0009] The attitude simulation mechanism includes a six-degree-of-freedom robotic arm and a direction-finding device support platform. The direction-finding device support platform holds the airborne direction-finding device in the microwave anechoic chamber, and the six-degree-of-freedom robotic arm performs precise movements in six degrees of freedom according to a set attitude trajectory to simulate the installation attitude of the airborne direction-finding device on the flight platform and the attitude changes generated when it moves with the flight platform.

[0010] The target simulation mechanism includes a target signal source and a support device. The target signal source generates a test signal with controllable polarization and waveform characteristics, and the transmission direction of the test signal is adjusted based on the support device.

[0011] The host computer terminal is used to configure and issue test and calibration tasks, and to establish communication with the six-degree-of-freedom robotic arm, the airborne direction finding equipment, the target signal source and the support device, and to monitor, analyze and manage the system operation status and calibration results.

[0012] In one possible implementation of the first aspect, the host computer terminal includes:

[0013] The scenario and task editing module is used to receive calibration requirements and simulation scenario parameters input by the user and generate a list of test and calibration tasks. Each task includes at least the flight platform type, equipment installation parameters, flight attitude time series, flight trajectory data, target trajectory data, test time axis, target signal source working parameters, and task execution mode. The task execution mode includes attitude simulation mode and actual flight data playback mode.

[0014] The attitude and scene simulation module is used to establish the geometric relationship between various coordinate systems based on the test and calibration task list, and to calculate the theoretical incident direction of the simulated target relative to the airborne direction finding equipment.

[0015] The motion control module is used to convert the theoretical incident direction output by the attitude and scene simulation module into control commands for the attitude simulation mechanism and the target simulation mechanism, and send them to the corresponding devices through the communication interface;

[0016] The data acquisition and calibration processing module is used to acquire the direction finding results output by the airborne direction finding equipment, the attitude information of the attitude simulation mechanism and the state information of the target simulation mechanism, calculate the direction finding error and generate corresponding calibration parameters.

[0017] The status monitoring module is used to receive the operating status, current task progress and alarm information reported by the six-degree-of-freedom robotic arm, the target signal source, the support device and the airborne direction finding equipment, and to display them graphically.

[0018] The results analysis and management module is used to perform offline analysis and evaluation of the calibration process data after the experiment, to visualize the distribution of direction finding errors and the effectiveness of calibration parameters, and to archive and manage the calibration results.

[0019] In one possible implementation of the first aspect, establishing the geometric relationships between various coordinate systems and calculating the theoretical incident direction of the simulated target relative to the airborne direction-finding device includes:

[0020] It includes a geographic coordinate system for describing the location of the flight platform and the simulated target, an aircraft body coordinate system for describing the attitude of the flight platform, a direction finding equipment coordinate system for describing the pointing relationship of the airborne direction finding equipment, an anechoic chamber coordinate system for describing the physical arrangement of the microwave anechoic chamber, a robot arm base coordinate system for describing the installation attitude of the six-degree-of-freedom robot arm, and an end flange coordinate system for describing the attitude of the end flange of the six-degree-of-freedom robot arm.

[0021] During the system debugging phase, the rigid transformation calibration of the darkroom coordinate system and the robotic arm base coordinate system, as well as the rigid transformation calibration of the direction finding equipment coordinate system and the end flange coordinate system, are completed.

[0022] Based on the established rigid transformation relationship of the coordinate system, the bidirectional pose transformation between different coordinate systems is completed through the cascade operation of homogeneous transformation matrices.

[0023] Based on the bidirectional pose transformation relationship between different coordinate systems, the absolute spatial position of the simulated target and the direction of the transmitting antenna in the anechoic chamber coordinate system are converted into the relative position and incident direction of the direction finding device relative to the phase center of the airborne direction finding device in the direction finding device coordinate system.

[0024] Based on the axial definition of the coordinate system of the direction finding device, the incident direction of the simulated target relative to the phase center of the airborne direction finding device is decomposed into the theoretical azimuth angle and the theoretical pitch angle.

[0025] In one possible implementation of the first aspect, the attitude and scene simulation module is further configured to:

[0026] The flight attitude and target scene simulation function includes: based on the flight attitude time series, flight trajectory data, and target trajectory data provided by the scene and task editing module, and combined with the bidirectional pose transformation relationship between different coordinate systems, calculating the theoretical incident azimuth angle and theoretical incident pitch angle of the simulated target relative to the aircraft body coordinate system and the direction finding equipment coordinate system at each moment;

[0027] The attitude mapping and inverse kinematics solution function includes: based on the bidirectional pose transformation relationship between different coordinate systems, mapping the desired pointing attitude in the coordinate system of the direction finding device to the coordinate system of the darkroom and the base coordinate system of the robot arm, and combining the kinematic model of the robot arm to solve the corresponding joint angle commands of the six-degree-of-freedom robot arm to form the attitude trajectory of the six-degree-of-freedom robot arm;

[0028] The real-time control and synchronization function includes: sending attitude control commands to the attitude simulation mechanism and working status control commands to the target simulation mechanism under a unified time reference, while receiving corresponding real-time feedback information for deviation verification and dynamic compensation, so that the geometric relationship between the attitude of the six-degree-of-freedom robotic arm and the direction of the simulated target test signal is consistent with the issued task scenario.

[0029] In one possible implementation of the first aspect, the data acquisition and calibration processing module is further configured to:

[0030] The data acquisition function includes: receiving the direction finding results output by the airborne direction finding device through the first communication interface, and synchronously acquiring the attitude information of the attitude simulation mechanism, the status information of the target simulation mechanism, and the system time information based on a unified time reference, to ensure that the timestamps of various data are consistent;

[0031] The true direction calculation function includes: based on the attitude information of the attitude simulation mechanism, the state information of the target simulation mechanism, and the bidirectional pose transformation relationship between each coordinate system, calculating the theoretical azimuth and theoretical pitch angles of the test signal corresponding to the simulated target incident in the coordinate system of the direction finding device, as the true direction finding value;

[0032] The error calculation and calibration parameter solving function includes: comparing the direction finding results output by the airborne direction finding equipment with the true direction finding value, obtaining the direction finding error data under different postures of the six-degree-of-freedom robotic arm and under different directions of the transmitting antenna, and automatically solving the corresponding calibration parameters based on the set algorithm;

[0033] The result storage and export function includes: storing the original measurement data, true values ​​of direction finding, error curves and corresponding calibration parameters of the airborne direction finding equipment in a local storage medium, and exporting them in a predetermined format.

[0034] In one possible implementation of the first aspect, the attitude simulation mechanism is connected to the host computer terminal via a second communication interface, for:

[0035] Based on the control commands issued by the motion control module regarding the attitude simulation mechanism, the six-degree-of-freedom robotic arm is driven to move along the calculated attitude trajectory at a predetermined sampling period, so that the airborne direction finding equipment can reproduce the same attitude change process as the flight platform in the microwave anechoic chamber.

[0036] The encoder collects the joint angles and end-effector poses of the six-degree-of-freedom robotic arm and feeds them back to the attitude and scene simulation module and the data acquisition and calibration processing module to calculate the real-time attitude of the airborne orientation finding device in the darkroom coordinate system.

[0037] In one possible implementation of the first aspect, the target simulation mechanism is connected to the host computer terminal via a third communication interface, for:

[0038] Based on the control commands issued by the motion control module regarding the target simulation mechanism, the operating parameters of the target signal source are configured, and a test signal compatible with the operating frequency band of the airborne direction finding equipment is generated during the test; the azimuth and elevation angles of the transmitting antenna are adjusted by the support device to change the transmission direction of the test signal;

[0039] The current operating mode and transmission status of the target signal source, as well as the attitude information of the support device, are fed back to the host computer terminal and recorded by the data acquisition and calibration processing module.

[0040] One possible implementation of the first aspect also includes:

[0041] When the task execution mode is attitude simulation calibration mode, the host computer terminal configures the virtual flight task and target scene through the scene and task editing module; the attitude and scene simulation module generates control commands for the attitude simulation mechanism and the target simulation mechanism based on the virtual flight task and target scene; the motion control module executes the control commands for the attitude simulation mechanism and the target simulation mechanism in the microwave anechoic chamber, so that the airborne direction finding equipment reproduces the predetermined flight conditions; the data acquisition and calibration processing module calculates and outputs the corresponding calibration parameters.

[0042] When the task execution mode is the real flight data playback mode, the host computer terminal imports the flight attitude, flight trajectory, and target trajectory data recorded in the real flight test of the flight platform. The attitude and scene simulation module generates the corresponding attitude and scene according to the real flight timeline of the flight platform. The motion control module drives the attitude simulation mechanism and the target simulation mechanism to replay the real flight conditions of the flight platform. The data acquisition and calibration processing module conducts multiple comparative tests with and without calibration parameters to verify the correction effect of the calibration parameters on the real flight scene of the flight platform.

[0043] In one possible implementation of the first aspect, the host computer terminal also reserves an external communication interface for an external flight simulation system. The external communication interface includes at least one serial communication interface and an Ethernet interface. The host computer terminal receives flight mission planning and target scenario information provided by the external flight simulation system through the external communication interface and generates a darkroom test scenario online.

[0044] In one possible implementation of the first aspect, the direction finding equipment carrier platform is equipped with a dedicated clamp to maintain a stable and reliable installation relationship between the airborne direction finding equipment and the direction finding equipment carrier platform.

[0045] Its beneficial effects are as follows: This invention discloses an anechoic chamber calibration and attitude simulation system for airborne direction finding equipment, comprising a microwave anechoic chamber, an attitude simulation mechanism, a target simulation mechanism, and a host computer terminal; the microwave anechoic chamber provides the test environment; the attitude simulation mechanism includes a six-degree-of-freedom robotic arm and an airborne direction finding equipment carrier platform, which grasps the airborne direction finding equipment and performs precise movements in six degrees of freedom according to a set attitude trajectory, simulating the flight conditions of the airborne direction finding equipment on the flight platform; the target simulation mechanism includes a target signal source and a support device, used to generate test signals with controllable direction, polarization, and waveform characteristics; the host computer terminal is used to configure and issue test and calibration tasks, and simultaneously perform monitoring, analysis, and management. This invention completes scenario-level testing and high-precision calibration of the entire test chain, reducing reliance on actual flight tests and solving the problem of limited degrees of freedom on ground platforms. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the composition of an airborne direction finding equipment calibration and attitude simulation system provided in an embodiment of this application;

[0048] Figure 2 This is a schematic diagram of the functional modules of the host computer terminal provided in the embodiments of this application. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0051] Example 1

[0052] The existing testing and calibration methods for airborne direction-finding equipment have the following problems:

[0053] 1) Over-reliance on flight testing leads to high testing costs and significant constraints: Flight testing requires flight platforms and pilot resources, has a long preparation cycle, and high organizational costs. At the same time, it is limited by various factors such as airspace control, weather conditions, and safety requirements, making it difficult to arrange repeated tests in multiple batches and scenarios in a timely and flexible manner, which is not conducive to carrying out a large number of iterative optimizations in the early stages of equipment development.

[0054] 2) The relationship between flight attitude and target geometry is difficult to control precisely and repeatably: Under actual flight conditions, the aircraft attitude, trajectory and target position are affected by factors such as weather, airflow and pilot operation, and can often only approximately meet the predetermined conditions; the attitude combination and target azimuth distribution vary greatly between different test flights, resulting in strong dispersion and poor repeatability of direction finding error data, which is not conducive to full and systematic coverage and analysis of certain sensitive attitude conditions (such as large roll, large angle of attack, and complex roll maneuvers).

[0055] 3) Limited degrees of freedom on simplified ground-based test platforms make it difficult to accurately reproduce airborne installation conditions: Existing ground-based tests typically use one-dimensional or two-dimensional turntables, or manually adjust pitch and azimuth angles on fixed supports. This limits the ability to change the equipment's orientation to only a few rotational degrees of freedom, making it difficult to simultaneously simulate the aircraft's heading, pitch, roll, and other attitude changes. Installation errors and structural deformations between the direction-finding equipment and the airframe are also difficult to accurately reproduce in this simplified support environment, resulting in discrepancies between anechoic chamber test results and actual performance after installation.

[0056] 4) Anechoic chamber testing often focuses on antenna specifications, lacking scenario-level verification for the entire direction-finding link: Traditional anechoic chamber testing is mostly used for testing single-unit specifications such as antenna pattern, gain, and isolation. Antennas or small transceiver units are typically mounted directly on a turntable. However, the navigation system, attitude reference, time synchronization, and upper-level direction-finding / positioning algorithms involved in airborne direction-finding systems are often not included in the same test loop. The test data obtained in this way cannot comprehensively reflect the integrated error characteristics of the entire link: "platform attitude - equipment installation - signal incident direction - direction-finding algorithm".

[0057] In summary, existing testing and calibration methods for airborne direction-finding equipment based on actual flight tests and simplified ground platforms have significant shortcomings in terms of testing costs, controllability of attitude and target geometry relationships, overall system-level verification capabilities, and data consistency. There is an urgent need for a system capable of accurately simulating flight platform attitude and equipment installation methods in a darkroom environment using high-degree-of-freedom mechanical actuators, combined with target signal simulation and unified data acquisition and processing software. This system would enable controlled scenario testing and high-precision calibration of airborne direction-finding equipment, thereby reducing testing costs and improving test repeatability and the reliability of calibration results.

[0058] Therefore, this application provides an anechoic chamber calibration and attitude simulation system for airborne direction finding equipment, such as... Figure 1 As shown, it includes:

[0059] Microwave anechoic chamber, attitude simulation mechanism, target simulation mechanism and host computer terminal;

[0060] The microwave anechoic chamber is used to provide a low-reflection, low-interference electromagnetic environment and serves as a reference space for establishing the anechoic chamber coordinate system.

[0061] The attitude simulation mechanism includes a six-degree-of-freedom robotic arm and a direction-finding device support platform. The direction-finding device support platform holds the airborne direction-finding device in the microwave anechoic chamber, and the six-degree-of-freedom robotic arm performs precise movements in six degrees of freedom according to a set attitude trajectory to simulate the installation attitude of the airborne direction-finding device on the flight platform and the attitude changes generated when it moves with the flight platform.

[0062] The target simulation mechanism includes a target signal source and a support device. The target signal source generates a test signal with controllable polarization and waveform characteristics, and the transmission direction of the test signal is adjusted based on the support device.

[0063] The host computer terminal is used to configure and issue test and calibration tasks, and to establish communication with the six-degree-of-freedom robotic arm, the airborne direction finding equipment, the target signal source and the support device, and to monitor, analyze and manage the system operation status and calibration results.

[0064] This embodiment provides an anechoic chamber calibration and attitude simulation system for airborne direction-finding equipment, specifically including:

[0065] A microwave anechoic chamber is used to provide a low-reflection, low-interference electromagnetic environment to avoid the influence of external signals on the experiment and to serve as a reference space for establishing the anechoic chamber coordinate system.

[0066] The attitude simulation mechanism includes a six-degree-of-freedom robotic arm and a direction finding equipment carrier platform. It is used to hold the airborne direction finding equipment inside the microwave anechoic chamber and move precisely in six degrees of freedom according to the set attitude trajectory to simulate the installation attitude of the airborne direction finding equipment on the aircraft and the attitude changes caused by the movement of the aircraft.

[0067] The target simulation mechanism includes a target signal source and a support device, which is used to generate test signals with controllable direction, polarization and waveform characteristics in an anechoic chamber. The test signal is emitted by a transmitting antenna, and the azimuth and elevation angles of the transmitting antenna are adjusted by adjusting the support device, thereby controlling the direction of the test signal.

[0068] The host computer terminal is used to configure and issue test and calibration tasks, run multiple software modules, and communicate with the six-degree-of-freedom robotic arm, target signal source, support device and airborne direction finding equipment through wired or wireless communication interfaces. It monitors, analyzes and manages the system operation status and calibration results.

[0069] Furthermore, the host computer terminal is equipped with a testing and calibration software system, which includes at least the following functional modules, such as... Figure 2 As shown:

[0070] Scene and Task Editing Module:

[0071] It is used to receive user input of calibration requirements and simulation scenario parameters, and generate a list of test and calibration tasks. Each task includes at least: flight platform type, equipment installation parameters, flight trajectory data (or flight attitude), target trajectory data (or target position information), test time axis, target signal source working parameters, and task execution mode. The task execution mode includes at least attitude simulation mode and actual flight data playback mode.

[0072] Its core principle is to decompose and standardize the parameterization of test requirements, transforming abstract calibration and simulation requirements into an executable, quantifiable task list, providing a unified execution basis for subsequent attitude simulation, equipment linkage, and data processing. For example, by defining the "flight platform type" and "equipment installation parameters," the installation benchmark of the airborne direction-finding equipment is clarified, ensuring that the installation conditions of the anechoic chamber test are consistent with the actual installation; by defining the "flight trajectory data" and "target trajectory data," the spatial motion scenario of the test is defined, which can be either a virtual full-condition attitude sequence or a real trajectory recorded in actual flight; by defining the "test time axis," the start and end times and sampling interval of the test are determined; by defining the "target signal source operating parameters" (carrier frequency, bandwidth, signal mechanism, etc.), the operating frequency band of the direction-finding equipment is matched to ensure the validity of the test signal; by defining the "task execution mode," the core objective of the test is clarified, with the attitude simulation mode used for basic performance calibration and the actual flight data playback mode used for calibration parameter verification, achieving accurate differentiation of different test objectives.

[0073] Attitude and Scene Simulation Module:

[0074] It is used to establish the geometric relationships between various coordinate systems based on the test and calibration task list, and to calculate the theoretical incident direction of the target relative to the airborne direction finding equipment.

[0075] Its attitude and scene simulation module has at least the following functions:

[0076] 1. Coordinate system modeling and transformation functions, used to establish and maintain multiple reference coordinate systems.

[0077] Its core principle is coordinate system modeling and pose cascade transformation. By establishing a rigid mapping relationship between various coordinate systems, it achieves a precise correlation between the virtual flight scene and the physical space of the darkroom, providing a reliable geometric benchmark for direction finding truth calculation and error analysis. Specifically, it is broken down into the following four key steps:

[0078] Multi-coordinate system hierarchical definition, clearly defining the boundaries of spatial description:

[0079] To address the spatial representation needs of different physical objects and scenarios, a dedicated coordinate system is constructed and its functions are divided, forming a complete spatial description system. The geographic coordinate system, serving as a global reference benchmark, is used to calibrate the macroscopic motion trajectory of the flight platform and the absolute spatial position of the target, acting as a link between the virtual flight mission and the real physical space. The aircraft body coordinate system, fixed to the flight platform fuselage, is used to represent the aircraft's own attitude changes such as heading, pitch, and roll, reflecting the platform's motion attitude characteristics. The direction-finding equipment coordinate system, fixed to the direction-finding equipment itself, uses the phase center of the direction-finding equipment antenna as the core reference point, describing the pointing relationship of the direction-finding equipment and serving as the core coordinate system for calculating the true value of direction finding. The anechoic chamber coordinate system, using the microwave anechoic chamber as the physical spatial benchmark, defines the fixed installation positions of all hardware equipment within the anechoic chamber, serving as the physical anchor point of the experimental scenario. The robotic arm base coordinate system, fixed to the robotic arm base, describes the installation attitude and range of motion of the robotic arm, serving as the basic reference for the robotic arm's motion control. The end flange coordinate system, fixed to the end flange of the robotic arm, serves as the direct carrier for the installation of the direction-finding equipment, transmitting the robotic arm's motion attitude to the airborne direction-finding equipment.

[0080] Rigid calibration of the critical coordinate system, establishing the basic transformation link:

[0081] During the system debugging phase, the rigid transformation calibration of two sets of core coordinate systems was completed, laying the foundation for subsequent cross-coordinate system transformations. The calibration of the anechoic chamber coordinate system and the robotic arm base coordinate system involved using geometric installation references (such as positioning marks and reference surfaces) within the anechoic chamber, along with calibration experiments, to measure the relative pose of the two coordinate systems. This was then converted into three-dimensional rotation parameters (characterizing angular deflection between coordinate systems) and three-dimensional translation parameters (characterizing spatial offset of the coordinate system origin) and stored, achieving unification between the physical anechoic chamber space and the robotic arm's motion space. The calibration of the direction-finding equipment coordinate system and the end flange coordinate system involved determining the rigid connection relationship between the two based on the physical installation parameters of the airborne direction-finding equipment at the end of the robotic arm, such as the mounting hole position, reference surface, tilt angle, and offset (this relationship is a fixed value and is unaffected by the robotic arm's movement). This allowed the real-time attitude of the direction-finding equipment in the robotic arm base coordinate system and the anechoic chamber coordinate system to be derived from the real-time pose of the end flange coordinate system.

[0082] Multi-coordinate system pose cascade transformation to achieve spatial information mapping:

[0083] Based on the established rigid transformation relationships, bidirectional pose transformation between different coordinate systems is achieved through cascaded operations of homogeneous transformation matrices. The transformation follows a "global → local" or "local → global" chain. For example, converting the absolute position of the target signal source in the anechoic chamber coordinate system to its relative position in the direction-finding equipment coordinate system requires sequential transformations: "anechoic chamber coordinate system → robotic arm base coordinate system → end flange coordinate system → direction-finding equipment coordinate system." Each transformation step is implemented using corresponding rotation and translation matrices, ultimately converting the target's absolute spatial position and antenna pointing into a three-dimensional incident vector relative to the phase center of the direction-finding equipment, eliminating spatial description differences between different coordinate systems.

[0084] Incident vector angle decomposition, generating the true value of the direction finding theory:

[0085] After obtaining the target incident vector in the direction-finding equipment's coordinate system, the three-dimensional vector is decomposed angularly according to the equipment's axial definitions (such as industry-standard or equipment-specific azimuth and pitch axis conventions). The incident vector is projected onto the horizontal plane of the direction-finding equipment's coordinate system, and the horizontal angles of the remaining reference axes are calculated to obtain the theoretical azimuth angle. The vertical angle between the incident vector and the horizontal plane is calculated to characterize the target's elevation relative to the direction-finding equipment, yielding the theoretical pitch angle. The theoretical azimuth and theoretical pitch angles obtained from the decomposition are the true direction-finding values ​​that the airborne direction-finding equipment should output. They serve as the core geometric basis for subsequent comparisons with actual equipment measurements, calculation of direction-finding errors, and generation of calibration parameters.

[0086] 2. Flight attitude and target scenario simulation function

[0087] Its core principle is multi-coordinate system spatial geometric mapping and vector angle decomposition. By transforming the spatiotemporal parameters of virtual / real flight scenarios through multi-coordinate system cascade transformation, the final solution is the theoretical incident angle relative to the airborne direction finding equipment, providing a basis for the true value of direction finding and error analysis. Specifically, it is broken down into the following three key steps:

[0088] Coordinate system classification and preprocessing of scene data:

[0089] First, the coordinate system affiliation of the basic data input into the scene and task editing module is defined to clarify the spatial reference benchmark of the data. For flight attitude time series and flight trajectory data, the original benchmarks are the geographic coordinate system and the aircraft body coordinate system; for target trajectory data (or target position information), the original benchmark is usually the geographic coordinate system, although in some scenarios the relative position in the aircraft body coordinate system may also be provided directly. Simultaneously, the data undergoes time-series alignment preprocessing to ensure that flight attitude, trajectory, and target information correspond one-to-one in the time dimension, laying the data foundation for subsequent time-by-time calculations.

[0090] Multi-coordinate system cascade transformation to achieve spatial position mapping:

[0091] Based on the calibrated rigid transformation relationships of each coordinate system, the target position is mapped layer by layer across coordinate systems. If the target is an absolute position in the geographic coordinate system, the transformation from the geographic coordinate system to the aircraft body coordinate system is first used to eliminate the position and attitude offset of the flight platform in geographic space, obtaining the three-dimensional spatial vector of the target relative to the aircraft body. Then, the transformation from the aircraft body coordinate system to the direction finding equipment coordinate system is used to further map the above relative vector to the dedicated coordinate system of the airborne direction finding equipment, obtaining the incident direction vector of the target relative to the phase center of the airborne direction finding equipment. This vector directly reflects the spatial incident path of the signal. The entire transformation process relies on pre-calibrated rotation and translation parameters to ensure the accuracy of the position mapping.

[0092] Decompose the incident vector angle to generate the theoretical azimuth and elevation angles:

[0093] After obtaining the incident direction vector in the coordinate system of the direction finding equipment, the incident direction vector is decomposed into angles according to the axial definition of the airborne direction finding equipment to obtain the theoretical azimuth and theoretical pitch angles.

[0094] 3. Attitude mapping and inverse kinematics solution function

[0095] Its core principle is coordinate system pose mapping and inverse kinematics calculation of the robotic arm. By converting the target posture of the direction-finding device into joint angle commands that the robotic arm can execute, the posture of the direction-finding device can be accurately reproduced in the physical space of the darkroom. Specifically, it can be broken down into three key steps:

[0096] Multi-coordinate system pose inverse mapping to determine the target pose of the robotic arm's end effector:

[0097] Based on the established coordinate system rigid transformation relationship, the cross-coordinate system inverse mapping of the desired attitude of the direction finding equipment is completed. Given the desired pointing attitude in the direction finding equipment coordinate system, the target attitude to be achieved in the end-effector coordinate system is first obtained through a rigid transformation from the direction finding equipment coordinate system to the end-effector coordinate system. Then, through transformations from the end-effector coordinate system to the robot arm base coordinate system, and from the robot arm base coordinate system to the anechoic chamber coordinate system, the target attitude of the end-effector coordinate system is synchronously mapped to the robot arm motion space and the anechoic chamber physical space. This clarifies the target pose of the robot arm end-effector under its own motion reference and the test scenario reference, realizing the conversion from virtual attitude requirements to physical space pose.

[0098] Inverse kinematics solution for the robotic arm, generating joint angle commands:

[0099] Based on the kinematic model of the robotic arm, inverse kinematics calculation is performed on the target pose in the coordinate system of the end effector flange. The kinematic model of the robotic arm includes two types of algorithms: forward kinematics (solving the end effector pose given the joint angles) and inverse kinematics (deriving the joint angles from the end effector pose). This embodiment applies the inverse kinematics algorithm, specifically: inputting the target pose of the end effector flange, and combining the inherent parameters of the robotic arm such as the joint structure, link length, and joint range of motion, the required rotation angle values ​​of each joint of the robotic arm are solved analytically or numerically to form a joint angle instruction set. During the solution process, the feasibility of the joint angles is also checked, and solutions that exceed the range of motion or have mechanical interference are eliminated to ensure the executability of the instructions.

[0100] Timing-based instruction generation to construct the robotic arm's posture trajectory:

[0101] For the desired attitude of the device at multiple moments corresponding to the flight attitude time series, the joint angle commands calculated at each moment are sorted according to the time axis and the trajectory is smoothed. According to the time sampling interval of the task, the discrete joint angle commands are transformed into continuous attitude trajectories to ensure that the movement of the robotic arm is smooth and without stuttering. At the same time, the movement speed and acceleration of the trajectory are constrained to balance the accuracy of attitude reproduction and the operational safety of the robotic arm, and finally a complete attitude trajectory command is generated and sent to the robotic arm controller.

[0102] 4. Real-time control and synchronization functions

[0103] Its core principle is multi-device collaborative linkage and geometric constraint transformation control under a unified time reference. Through time synchronization, command linkage, and real-time deviation compensation, it ensures that the spatial geometric relationship between the robotic arm's posture and the target signal direction accurately matches the task scenario. First, a globally unified time reference system is established to timestamp the control commands and status feedback of all devices. Then, relying on the spatial geometric mapping relationship pre-calculated by the posture and scenario simulation module, command linkage between the robotic arm and the target signal source is realized. During command execution, a closed-loop verification link is constructed through device feedback to maintain the geometric matching accuracy between the robotic arm's posture and the target signal direction. If a deviation occurs, a dynamic compensation command is immediately triggered to fine-tune the joint angle of the robotic arm or the antenna angle of the target signal source to correct the deviation and ensure that the spatial geometric relationship between the two always conforms to the preset requirements of the task scenario.

[0104] Motion control module:

[0105] Its core principle is the combination of spatial geometric command mapping, device command adaptation and communication link scheduling. By converting the theoretical geometric data of attitude simulation into control commands that can be recognized by each execution device, it achieves accurate command issuance and coordinated execution, ensuring the physical reproduction of the test scenario.

[0106] First, the theoretical incident direction of the target, output by the attitude and scene simulation module, is received and broken down into specific motion requirements for the six-degree-of-freedom manipulator, the target signal source, and the support device. For the six-degree-of-freedom manipulator, the desired attitude of the direction-finding device corresponding to the target incident direction is transformed into the target pose of the end flange of the manipulator by combining multi-coordinate system transformation relationships, clarifying the spatial state that the manipulator needs to achieve, which serves as the core requirement for the manipulator's motion. For the target signal source and the support device, the theoretical incident direction of the target is transformed into the working parameter requirements of the target signal source (such as carrier frequency, bandwidth, signal mechanism, etc., which need to match the working frequency band of the direction-finding device) and the antenna pointing requirements of the support device (such as the adjustment of azimuth and elevation angles), ensuring that the characteristics and direction of the transmitted signal are consistent with the theoretical scene.

[0107] For different devices, the motion requirements of these devices are transformed into directly executable dedicated instructions based on their control logic and command protocols. These instructions are for the attitude simulation mechanism and the target simulation structure. Finally, the instructions are scheduled and issued through a preset communication interface according to a unified time base.

[0108] Data acquisition and calibration processing module:

[0109] Its core principle is multi-source data synchronous acquisition, accurate calculation of direction finding true values, error analysis and parameter fitting. By constructing an automatic closed loop of "data acquisition - true value comparison - error modeling - parameter generation", it achieves high-precision calibration of airborne direction finding equipment, specifically implementing the following functions:

[0110] 1. Data acquisition function

[0111] The system receives direction-finding results from the airborne direction-finding equipment via the first communication interface. Then, relying on a unified timestamp, it achieves precise synchronous acquisition of multi-source data, ensuring a one-to-one temporal correspondence among various data types. The system collects output data from the airborne direction-finding equipment, including measured azimuth, elevation, and measurement confidence levels—core direction-finding results. It also collects attitude data from the six-degree-of-freedom robotic arm, using joint angles and end-effector pose feedback from the encoder to determine the real-time spatial attitude of the direction-finding equipment in the anechoic chamber coordinate system. Finally, it collects status data from the target signal source and support device, such as the carrier frequency, bandwidth, and signal mechanism of the target signal source, as well as the antenna azimuth and elevation angles of the support device, clarifying the characteristics of the test signal and the incident direction reference. All data is bound to the same system timestamp to eliminate the impact of timing deviations on subsequent error calculations.

[0112] 2. Truth value direction calculation function

[0113] Based on the synchronously acquired states of the six-degree-of-freedom robotic arm and the target signal source, the true value of the direction finding theory is calculated through multi-coordinate system cascade transformation, serving as the benchmark for error judgment. First, according to the calibration coefficients of the robotic arm base coordinate system and the anechoic chamber coordinate system, and the coordinate system of the robotic arm end flange and the direction finding equipment, the end pose fed back by the robotic arm is converted into the real-time pose of the direction finding equipment in the anechoic chamber coordinate system. Then, combined with the physical position of the target signal source in the anechoic chamber coordinate system and the antenna pointing, the absolute incident direction of the target signal is converted into the relative incident direction in the direction finding equipment coordinate system through homogeneous transformation matrix operations. Finally, according to the axial definition of the direction finding equipment, the incident direction is decomposed into the theoretical azimuth angle and the theoretical elevation angle, i.e., the true value of the direction finding.

[0114] 3. Error calculation and calibration parameter solution function

[0115] The measured values ​​of the direction finding equipment were compared point by point with the calculated theoretical true values ​​to complete the error statistics under different operating conditions. The azimuth and pitch angle errors of a single sample were calculated and classified according to the operating conditions of the test mission (such as different flight attitudes, different target incident directions, and different signal mechanisms). The error mean, variance, extreme values ​​and other characteristics of each type of operating condition were statistically analyzed to identify the error-sensitive operating conditions of the direction finding equipment, providing a basis for the targeted optimization of subsequent calibration parameters.

[0116] For the statistically obtained error data, suitable calibration parameters or correction tables are generated through mathematical modeling and algorithm fitting to achieve error compensation. If the error is caused by equipment installation deviation, the installation error matrix can be solved by fitting multi-point error data to establish a linear mapping relationship between error and installation attitude for subsequent real-time attitude compensation. If the error exhibits a non-linear distribution or is strongly correlated with the target incident direction, an azimuth / pitch correction table is generated through interpolation algorithms to provide accurate correction values ​​for direction finding results under different incident directions. The generated calibration parameters are verified for validity simultaneously, ultimately forming standardized correction data that can be imported into airborne direction finding equipment, completing the calibration closed loop.

[0117] 4. Results storage and export functions

[0118] Its core principle is data classification, archiving, and standardized format adaptation. By establishing a structured data storage system and a multi-scenario compatible export format, it achieves orderly management and cross-system reuse of experimental data. The various types of data generated throughout the experiment are roughly divided into three layers: raw data, intermediate data, and result data. The raw data layer consists of unprocessed basic data, including the original direction finding results from the airborne direction finding equipment, the joint angle / end-effector pose feedback of the six-DOF robotic arm, the working parameter records of the target signal source, the status logs of each system device, and unified timestamps, preserving the originality and integrity of the data and providing a basis for subsequent traceability and review. The intermediate data layer consists of derived data from preliminary calculations, such as the true direction finding values ​​obtained based on multi-coordinate system transformation, the direction finding error values ​​generated by point-by-point comparison, and visualized error curve data. This type of data is the core intermediate carrier for analyzing the performance of the direction finding equipment. The result data layer consists of the final calibration results data, such as the installation error matrix, azimuth / elevation correction table, and calibration parameter validity verification report, serving as the core data directly used for the calibration of the direction finding equipment.

[0119] Status monitoring module:

[0120] It is used to receive the operating status, current task progress and alarm information reported by the six-degree-of-freedom robotic arm, target signal source, support device and airborne direction finding equipment, and display them graphically.

[0121] Results Analysis and Management Module:

[0122] It is used to perform offline analysis and evaluation of the calibration process data after the test, to visualize the distribution of direction finding error and the effectiveness of calibration parameters, and to archive and manage the calibration results.

[0123] Furthermore, the attitude simulation mechanism connects to the host computer terminal via a second communication interface to achieve:

[0124] Based on the joint angle or end-effector pose commands issued by the motion control module, the robotic arm is driven to move along the attitude trajectory at a predetermined sampling period, so that the airborne direction finding equipment can reproduce the same or similar attitude change process as the flight platform in the microwave anechoic chamber.

[0125] The encoder provides feedback on the angles of each joint of the robotic arm and the end-effector pose, which are then used by the attitude and scene simulation module and the data acquisition and calibration processing module to calculate the real-time attitude of the orientation finding device in the darkroom coordinate system.

[0126] Provide a support platform or fixture for mounting the direction finding equipment to maintain a stable and reliable mounting relationship of the direction finding equipment at the end of the robotic arm.

[0127] Furthermore, the target simulation mechanism connects to the host computer terminal via a third communication interface to achieve:

[0128] Based on the control commands generated by the motion control module or attitude and scene simulation module, configure the operating parameters of the signal source, such as carrier frequency, bandwidth, pulse mechanism or continuous wave mechanism, and generate test signals compatible with the operating frequency band of the airborne direction finding equipment during the test.

[0129] The azimuth and elevation angles of the transmitting antenna are adjusted by the support device to form a test beam from a predetermined direction, or a simplified scan is performed according to the requirements of the scenario.

[0130] The target signal source’s current operating mode, transmission status, and the attitude information of the support device are fed back to the host computer terminal, where the data acquisition and calibration processing module records them and participates in the calculation of the true direction.

[0131] This embodiment provides an airborne direction finding equipment anechoic chamber calibration and attitude simulation system that supports at least two working modes (task execution modes):

[0132] When the working mode is attitude simulation calibration mode, the host computer terminal decomposes the user's calibration requirements and virtual flight scenario into quantifiable and executable standardized parameters through the scene and task editing module; the attitude and scene simulation module, based on the decomposed task list, achieves accurate mapping from the virtual scene to the physical space of the darkroom through multi-coordinate system unified modeling and cascade transformation; the motion control module, based on a unified time reference, drives the robotic arm and target signal source to work together to reproduce the virtual flight conditions in the darkroom. The entire process verifies the motion accuracy through equipment feedback to ensure that the geometric relationship between the robotic arm's attitude and the target signal direction always fits the issued task scenario; the data acquisition and calibration processing module, based on a unified timestamp, completes the synchronous acquisition and true value calculation of all data; finally, error analysis is completed by comparing the measured values ​​with the true values, and calibration parameters are generated based on the algorithm to form a calibration closed loop.

[0133] When the working mode is the live flight data playback mode, the host computer terminal first imports the panoramic data (flight attitude, flight trajectory, target trajectory) of the real flight test and preprocesses the data (format standardization conversion, precise timing alignment); the attitude and scene simulation module, based on the aligned live flight data, maps the live flight scene to the physical space of the anechoic chamber through multi-level coordinate system cascade transformation; the motion control module, based on a unified time reference, drives the robotic arm and target signal source to accurately reproduce the live flight conditions in the anechoic chamber; the data acquisition and calibration processing module completes the validity verification of the calibration parameters through a comparative test of "loading / not loading calibration parameters", and finally evaluates the correction effect of the calibration parameters on the live flight scene by comparing the error data of the two types of data. If the correction is insufficient, the parameters can be iteratively optimized based on the reproduced sensitive conditions.

[0134] Furthermore, the host computer terminal also reserves an external communication interface for interfacing with an external test management system or flight simulation system. This external communication interface includes at least one serial communication interface and one Ethernet interface. The host computer terminal receives flight mission planning, attitude prediction data or target scene information provided by the external simulation system through this interface, and uses it to generate darkroom test scenarios online.

[0135] Optionally, the host computer terminal can send the current test task status, attitude simulation progress, and calibration results to the higher-level test management platform through an external communication interface to achieve unified scheduling and management.

[0136] This embodiment is based on an airborne direction finding equipment anechoic chamber calibration and attitude simulation system using a six-degree-of-freedom robotic arm. It integrates functions such as attitude and scene simulation, motion control, data acquisition and calibration processing into a unified host computer software. With the help of the anechoic chamber environment, the six-degree-of-freedom robotic arm and the target signal source, it can accurately simulate the spatial geometric relationship of the flight platform and the target in the anechoic chamber, and complete the scene-level testing and high-precision calibration of the entire direction finding link. This reduces the dependence on actual flight tests and improves the reliability and repeatability of the test.

[0137] This embodiment provides an airborne direction-finding equipment anechoic chamber calibration and attitude simulation system, which makes at least the following technical contributions compared to existing technologies:

[0138] 1) By setting up scene and task editing modules, attitude and scene simulation modules, and motion control modules in the host computer terminal, the test conditions that originally relied on the geometric relationship between the real flight platform and the natural target are abstracted into configurable flight attitude time series, flight trajectory data, and target trajectory data, which are then reconstructed in an anechoic chamber using a six-degree-of-freedom robotic arm and a target signal source. Compared with existing methods that rely on actual flight tests, this embodiment can reproduce various flight attitude combinations and target orientation scenarios in a ground-based anechoic chamber environment without occupying flight platform and airspace resources, significantly reducing test costs and organizational difficulties. At the same time, it breaks through the limitations of weather, airspace, and safety conditions on the test window, enabling airborne direction finding equipment to undergo high-frequency, repeatable scenario-level testing and calibration during the R&D, type approval, and maintenance stages.

[0139] 2) By setting up coordinate system modeling and transformation functions in the host computer terminal, the geometric relationships between the geographic coordinate system, aircraft body coordinate system, direction-finding equipment coordinate system, anechoic chamber coordinate system, and relevant coordinate systems of the robotic arm are uniformly established. Combined with the installation parameters of the robotic arm end effector, the spatial position and attitude of the airborne direction-finding equipment in the anechoic chamber are accurately described. Furthermore, with the flight attitude and target scene simulation functions, the physical arrangement of the target signal source in the anechoic chamber is linked to the virtual flight scene, automatically calculating the theoretical incident azimuth and pitch angles of the target relative to the direction-finding equipment. This solves the problem that various test platforms in related technologies can only simply rotate equipment on a one-dimensional or two-dimensional turntable, failing to accurately reflect the superimposed installation errors of flight attitude. It allows the calibration process to be carried out under the comprehensive consideration of the combined effects of aircraft attitude, equipment installation deviation, and target spatial position, more closely reflecting actual installation conditions and improving the realism of direction-finding error modeling and calibration parameters.

[0140] 3) By employing a six-degree-of-freedom robotic arm to carry the airborne direction-finding equipment, and with the motion control module generating the robotic arm's attitude trajectory based on simulation results, the system achieves combined three-translation and three-rotation control of the equipment within the darkroom. Compared to existing simplified platforms that rely solely on single-axis or dual-axis turntables to change the equipment's azimuth or pitch, this embodiment can simulate the superimposed effects of various attitude changes such as aircraft heading, pitch, and roll, and even simulate dynamic attitude changes during complex maneuvers, making the attitude sequence experienced by the direction-finding equipment within the darkroom closer to the real flight environment. This overcomes the limitations of related technologies, such as insufficient degrees of freedom in experimental attitudes and difficulty in covering extreme attitude conditions and complex combinations of attitudes. It facilitates the systematic exposure of the performance boundaries of direction-finding algorithms under sensitive attitudes such as large roll and large pitch, and allows for the targeted development and verification of calibration schemes.

[0141] 4) By integrating a data acquisition and calibration processing module into the host computer terminal, the module synchronously acquires the azimuth, elevation, and other direction-finding results output by the airborne direction-finding equipment, as well as the robot arm's attitude, target signal source status, and system time information via a communication interface. Simultaneously, it automatically calculates the theoretical incident direction of the target in the direction-finding equipment's coordinate system based on a unified coordinate transformation relationship, and compares the direction-finding results with the theoretical true value point-by-point to form the direction-finding error distribution under different attitudes and pointing conditions. This module further supports the automatic solution of calibration parameters such as the installation error matrix and azimuth / elevation correction tables based on multi-point fitting and interpolation algorithms, and centralizes the storage management of raw data, true directions, and calibration results. This solves the problems of separate recording by each device and reliance on manual alignment and calculation after testing in related technologies, which leads to a large workload, high error rates, and difficulty in traceability in error analysis. It achieves the integration and automation of direction-finding true value calculation, error statistics, and calibration parameter solution, improving the efficiency, accuracy, and traceability of calibration work.

[0142] 5) By setting up two working modes—attitude simulation calibration mode and live flight data playback mode—the attitude simulation calibration mode utilizes virtual flight missions and ideal target scenarios to perform comprehensive basic performance calibration of the airborne direction finding equipment. In live flight data playback mode, the aircraft attitude, flight trajectory, and target trajectory recorded in real flight tests are imported into the host computer terminal. In a darkroom, the robotic arm and target signal source are driven to reconstruct the actual flight geometry, and the direction finding results for the same flight scenario with and without calibration parameters are compared and verified. This allows for rapid initialization and calibration of the algorithm and hardware in a laboratory environment, and enables the reproduction and iterative verification of problems found in live flight data without increasing the number of additional flight sorties. This solves the pain points of the disconnect between calibration and verification in related technologies, and the difficulty in reproducing live flight problems on the ground, significantly improving the testing and verification capabilities of airborne direction finding equipment throughout its entire lifecycle.

[0143] 6) By integrating functions such as scene and task editing, attitude and scene simulation, motion control, data acquisition and calibration processing, status monitoring, and result analysis and management into a single host computer terminal, and linking it with the six-degree-of-freedom robotic arm, target signal source, and airborne direction-finding equipment within the microwave anechoic chamber via a unified communication interface, the previously fragmented experimental control, data acquisition, and offline analysis processes are formed into a closed loop. This integrated architecture allows users to complete experimental task configuration, system status monitoring, online result viewing, and offline report generation on a single interface, reducing the workload of coordinating multiple independent devices and manually stitching data. This solves the problems of low integration, complex engineering implementation, and poor scalability in related technologies, improves the engineering usability and scalability of the airborne direction-finding equipment anechoic chamber test platform, and reserves interface and software expansion space for subsequent integration with different models of direction-finding equipment or the addition of other sensor calibration functions.

[0144] In some embodiments, the host computer terminal includes:

[0145] The scenario and task editing module is used to receive calibration requirements and simulation scenario parameters input by the user and generate a list of test and calibration tasks. Each task includes at least the flight platform type, equipment installation parameters, flight attitude time series, flight trajectory data, target trajectory data, test time axis, target signal source working parameters, and task execution mode. The task execution mode includes attitude simulation mode and actual flight data playback mode.

[0146] The attitude and scene simulation module is used to establish the geometric relationship between various coordinate systems based on the test and calibration task list, and to calculate the theoretical incident direction of the simulated target relative to the airborne direction finding equipment.

[0147] The motion control module is used to convert the theoretical incident direction output by the attitude and scene simulation module into control commands for the attitude simulation mechanism and the target simulation mechanism, and send them to the corresponding devices through the communication interface;

[0148] The data acquisition and calibration processing module is used to acquire the direction finding results output by the airborne direction finding equipment, the attitude information of the attitude simulation mechanism and the state information of the target simulation mechanism, calculate the direction finding error and generate corresponding calibration parameters.

[0149] The status monitoring module is used to receive the operating status, current task progress and alarm information reported by the six-degree-of-freedom robotic arm, the target signal source, the support device and the airborne direction finding equipment, and to display them graphically.

[0150] The results analysis and management module is used to perform offline analysis and evaluation of the calibration process data after the experiment, to visualize the distribution of direction finding errors and the effectiveness of calibration parameters, and to archive and manage the calibration results.

[0151] In some embodiments, establishing the geometric relationships between various coordinate systems and calculating the theoretical incident direction of the simulated target relative to the airborne direction-finding device includes:

[0152] It includes a geographic coordinate system for describing the location of the flight platform and the simulated target, an aircraft body coordinate system for describing the attitude of the flight platform, a direction finding equipment coordinate system for describing the pointing relationship of the airborne direction finding equipment, an anechoic chamber coordinate system for describing the physical arrangement of the microwave anechoic chamber, a robot arm base coordinate system for describing the installation attitude of the six-degree-of-freedom robot arm, and an end flange coordinate system for describing the attitude of the end flange of the six-degree-of-freedom robot arm.

[0153] During the system debugging phase, the rigid transformation calibration of the darkroom coordinate system and the robotic arm base coordinate system, as well as the rigid transformation calibration of the direction finding equipment coordinate system and the end flange coordinate system, are completed.

[0154] Based on the established rigid transformation relationship of the coordinate system, the bidirectional pose transformation between different coordinate systems is completed through the cascade operation of homogeneous transformation matrices.

[0155] Based on the bidirectional pose transformation relationship between different coordinate systems, the absolute spatial position of the simulated target and the direction of the transmitting antenna in the anechoic chamber coordinate system are converted into the relative position and incident direction of the direction finding device relative to the phase center of the airborne direction finding device in the direction finding device coordinate system.

[0156] Based on the axial definition of the coordinate system of the direction finding device, the incident direction of the simulated target relative to the phase center of the airborne direction finding device is decomposed into the theoretical azimuth angle and the theoretical pitch angle.

[0157] In some embodiments, the attitude and scene simulation module is further configured to implement:

[0158] The flight attitude and target scene simulation function includes: based on the flight attitude time series, flight trajectory data, and target trajectory data provided by the scene and task editing module, and combined with the bidirectional pose transformation relationship between different coordinate systems, calculating the theoretical incident azimuth angle and theoretical incident pitch angle of the simulated target relative to the aircraft body coordinate system and the direction finding equipment coordinate system at each moment;

[0159] The attitude mapping and inverse kinematics solution function includes: based on the bidirectional pose transformation relationship between different coordinate systems, mapping the desired pointing attitude in the coordinate system of the direction finding device to the coordinate system of the darkroom and the base coordinate system of the robot arm, and combining the kinematic model of the robot arm to solve the corresponding joint angle commands of the six-degree-of-freedom robot arm to form the attitude trajectory of the six-degree-of-freedom robot arm;

[0160] The real-time control and synchronization function includes: sending attitude control commands to the attitude simulation mechanism and working status control commands to the target simulation mechanism under a unified time reference, while receiving corresponding real-time feedback information for deviation verification and dynamic compensation, so that the geometric relationship between the attitude of the six-degree-of-freedom robotic arm and the direction of the simulated target test signal is consistent with the issued task scenario.

[0161] In some embodiments, the data acquisition and calibration processing module is further configured to:

[0162] The data acquisition function includes: receiving the direction finding results output by the airborne direction finding device through the first communication interface, and synchronously acquiring the attitude information of the attitude simulation mechanism, the status information of the target simulation mechanism, and the system time information based on a unified time reference, to ensure that the timestamps of various data are consistent;

[0163] The true direction calculation function includes: based on the attitude information of the attitude simulation mechanism, the state information of the target simulation mechanism, and the bidirectional pose transformation relationship between each coordinate system, calculating the theoretical azimuth and theoretical pitch angles of the test signal corresponding to the simulated target incident in the coordinate system of the direction finding device, as the true direction finding value;

[0164] The error calculation and calibration parameter solving function includes: comparing the direction finding results output by the airborne direction finding equipment with the true direction finding value, obtaining the direction finding error data under different postures of the six-degree-of-freedom robotic arm and under different directions of the transmitting antenna, and automatically solving the corresponding calibration parameters based on the set algorithm;

[0165] The result storage and export function includes: storing the original measurement data, true values ​​of direction finding, error curves and corresponding calibration parameters of the airborne direction finding equipment in a local storage medium, and exporting them in a predetermined format.

[0166] In some embodiments, the attitude simulation mechanism is connected to the host computer terminal via a second communication interface, for the purpose of:

[0167] Based on the control commands issued by the motion control module regarding the attitude simulation mechanism, the six-degree-of-freedom robotic arm is driven to move along the calculated attitude trajectory at a predetermined sampling period, so that the airborne direction finding equipment can reproduce the same attitude change process as the flight platform in the microwave anechoic chamber.

[0168] The encoder collects the joint angles and end-effector poses of the six-degree-of-freedom robotic arm and feeds them back to the attitude and scene simulation module and the data acquisition and calibration processing module to calculate the real-time attitude of the airborne orientation finding device in the darkroom coordinate system.

[0169] In some embodiments, the target simulation mechanism is connected to the host computer terminal via a third communication interface, for the purpose of:

[0170] Based on the control commands issued by the motion control module regarding the target simulation mechanism, the operating parameters of the target signal source are configured, and a test signal compatible with the operating frequency band of the airborne direction finding equipment is generated during the test; the azimuth and elevation angles of the transmitting antenna are adjusted by the support device to change the transmission direction of the test signal;

[0171] The current operating mode and transmission status of the target signal source, as well as the attitude information of the support device, are fed back to the host computer terminal and recorded by the data acquisition and calibration processing module.

[0172] In some embodiments, it also includes:

[0173] When the task execution mode is attitude simulation calibration mode, the host computer terminal configures the virtual flight task and target scene through the scene and task editing module; the attitude and scene simulation module generates control commands for the attitude simulation mechanism and the target simulation mechanism based on the virtual flight task and target scene; the motion control module executes the control commands for the attitude simulation mechanism and the target simulation mechanism in the microwave anechoic chamber, so that the airborne direction finding equipment reproduces the predetermined flight conditions; the data acquisition and calibration processing module calculates and outputs the corresponding calibration parameters.

[0174] When the task execution mode is the real flight data playback mode, the host computer terminal imports the flight attitude, flight trajectory, and target trajectory data recorded in the real flight test of the flight platform. The attitude and scene simulation module generates the corresponding attitude and scene according to the real flight timeline of the flight platform. The motion control module drives the attitude simulation mechanism and the target simulation mechanism to replay the real flight conditions of the flight platform. The data acquisition and calibration processing module conducts multiple comparative tests with and without calibration parameters to verify the correction effect of the calibration parameters on the real flight scene of the flight platform.

[0175] In some embodiments, the host computer terminal also reserves an external communication interface for an external flight simulation system. The external communication interface includes at least one serial communication interface and an Ethernet interface. The host computer terminal receives flight mission planning and target scenario information provided by the external flight simulation system through the external communication interface and generates a darkroom test scenario online.

[0176] In some embodiments, the direction finding equipment carrier platform is equipped with a dedicated clamp to maintain a stable and reliable installation relationship between the airborne direction finding equipment and the direction finding equipment carrier platform.

[0177] Example 2

[0178] In this embodiment, the anechoic chamber calibration and attitude simulation system for airborne direction finding equipment is deployed in a microwave anechoic chamber to test, reproduce, and calibrate the direction finding performance of airborne direction finding equipment under near-real installation conditions and flight attitudes.

[0179] The system in this embodiment includes:

[0180] 1. Host computer terminal

[0181] An industrial computer is configured as a host computer terminal in the control room outside the microwave anechoic chamber. The testing and calibration software of this embodiment is installed and connected to the six-degree-of-freedom robotic arm controller, the target signal source control interface, and the data interface of the airborne direction finding equipment via Ethernet.

[0182] The host computer terminal is used for:

[0183] Import or edit flight attitude data, target orientation data, and test mission parameters;

[0184] Software modules for motion and scene simulation, motion control, data acquisition and calibration processing, etc.

[0185] Real-time monitoring of robotic arm posture, target signal source status, and direction finding equipment output;

[0186] After the experiment, the collected data and calibration results were analyzed offline.

[0187] 2. Microwave anechoic chamber and six-degree-of-freedom robotic arm

[0188] In this embodiment, the experiment was conducted in a microwave anechoic chamber with operating frequency bands covering L-band to W-band. The internal space of the anechoic chamber is approximately 22m × 10m × 9m. The four walls, ceiling and floor are covered with microwave absorbing materials to provide a low-reflection and low-interference electromagnetic environment.

[0189] A FANUC high-precision six-axis industrial robot is installed inside the darkroom as a mechanical actuator. The robot has six rotating joints and the repeatability of positioning can preferably reach ±0.05°. The robot arm is fixed to the floor or platform of the darkroom through a special foundation. Its base coordinate system has been calibrated during the manufacturing and installation of the robot arm in the darkroom and during the debugging stage.

[0190] In this embodiment, to simplify implementation and control, the robotic arm base coordinate system is used as the reference coordinate system for the test space. The darkroom coordinate system and the robotic arm base coordinate system are considered to coincide or are equivalently processed through a fixed transformation relationship. During the test, the host computer software can specify the target position and attitude of the robot head assembly in the robotic arm coordinate system through the robotic arm controller interface, including the position coordinates in three-dimensional space and the equivalent azimuth, pitch, and roll angles. The robotic arm drives the end effector to complete the attitude simulation according to these instructions.

[0191] 3. Target signal source and two-dimensional movable transmitter (support device)

[0192] In this embodiment, the target signal source adopts existing radar signal source equipment on the market, and the model can be selected as needed. This equipment can output analog signals of various radar mechanisms according to external control commands, including conventional pulse, linear frequency modulation and other intra-pulse / inter-pulse modulation mechanisms.

[0193] The target signal source is fixedly mounted on a platform at one end of the anechoic chamber. Its RF output is connected to a standard gain horn antenna mounted on a two-dimensional movable transmitter rack via a low-loss coaxial cable. The two-dimensional transmitter rack consists of two mutually orthogonal linear guide rails, which can achieve two-dimensional translation in the horizontal and vertical directions within a plane, used to change the spatial position of the horn antenna within the anechoic chamber. During installation, the horn antenna's main lobe direction is fixed to a predetermined attitude using a mechanical positioning fixture; azimuth and pitch rotation degrees of freedom are not provided in this embodiment.

[0194] The two-dimensional transmitter is controlled via a local controller or a communication interface with a host computer. Before the test, the antenna can be moved to several preset typical positions to form different target space geometric conditions. The corresponding transmitter position parameters are recorded in the robotic arm coordinate system and used for subsequent true orientation calculations.

[0195] 4. The airborne direction finding equipment under test and the nose tooling (direction finding equipment support platform)

[0196] To simulate real-world installation conditions as closely as possible, this embodiment directly uses the nose section of a UAV as the mounting carrier for the device under test. Specifically, the airborne direction-finding equipment is fixed inside the nose of the UAV according to the design and installation method on the aircraft, and a corresponding radome is installed to ensure that the shape and structure of the radome have as similar an impact on ray propagation as possible to the actual installation conditions.

[0197] To achieve a reliable connection between the nose section and the end effector of the robotic arm, this embodiment designs a dedicated nose section mounting fixture. This fixture connects to the end effector flange of the robotic arm using a standard mechanical interface, fixing the entire "nose section structure + direction finding equipment + radome" to the end effector of the robotic arm. Therefore, the attitude changes of the robotic arm can be directly equated to the attitude changes of the aircraft nose and direction finding equipment, facilitating the reproduction of the aircraft's geometric relationships during flight within a darkroom.

[0198] After the airborne orientation finding equipment under test is powered on, it connects to the host computer terminal through a data interface. The host computer can receive the orientation finding results in real time, including estimated azimuth angle, elevation angle and related status information.

[0199] 5. Software Function Division

[0200] In this embodiment, the software functions are mainly concentrated on the host computer terminal, and are mainly divided as follows:

[0201] 1) Scene and Task Editing Module

[0202] It provides a task editing interface, allowing users to configure for each test task: flight attitude time series (or flight trajectory data); target direction or target position sequence (which can be a live flight record or a virtual configuration); test time axis settings, attitude sampling interval; target signal source operating frequency band and radar signal mechanism parameters; and the selected two-dimensional transmitter position and condition set.

[0203] Save the configured task information as a task file for subsequent attitude simulation and test execution modules to use.

[0204] 2) Attitude and Scene Simulation Module

[0205] Import UAV attitude data and target direction data recorded in actual flight tests, or generate virtual flight missions based on user configuration;

[0206] Map the attitude parameters such as heading, pitch, and roll in the flight record to the target attitude of the nose assembly in the coordinate system of the robotic arm;

[0207] Based on the currently selected two-dimensional transmitter position, the theoretical incident azimuth and elevation angles of the target signal relative to the direction finding equipment under the corresponding operating conditions are calculated to form true direction time series data.

[0208] 3) Motion control module

[0209] Based on the head target attitude time series generated by the attitude and scene simulation module, the attitude trajectory command of the robotic arm end effector is generated.

[0210] The pose control command is sent to the FANUC six-axis robotic arm controller via Ethernet or fieldbus interface to drive the robotic arm to move along the predetermined trajectory;

[0211] When necessary, the robot arm's motion is subject to speed and acceleration constraints and trajectory smoothing.

[0212] 4) Data Acquisition and Calibration Processing Module

[0213] The system receives direction finding results from airborne direction finding equipment in real time via a communication interface, and collects information such as robotic arm attitude feedback, target signal source status, and launcher position.

[0214] Based on the geometric relationships and attitude simulation results in the robotic arm coordinate system, the theoretical incident azimuth and pitch angles at each sampling time are calculated as the true values ​​for direction finding.

[0215] The measurement results are compared with the true direction point by point, and the direction finding error under different attitudes and target directions is statistically analyzed.

[0216] Algorithms such as fitting or interpolation are used to solve for calibration parameters, such as installation error correction matrices or azimuth / elevation correction tables;

[0217] The system stores raw data, true values, error statistics, and calibration results on a task-by-task basis and supports exporting.

[0218] 5) Status monitoring and result analysis module

[0219] Real-time display of the robotic arm's current posture, launcher position, signal source working status, and direction finding equipment output;

[0220] Displays the current task's execution progress and running status;

[0221] After the test, the distribution of direction finding error and the effects before and after calibration can be visualized and analyzed to generate a test report.

[0222] Taking a real flight data playback calibration task as an example, its execution process includes the following steps:

[0223] 1. Flight data preparation and mission configuration

[0224] Before the test, the user selects data from a specific UAV flight test as the attitude and target direction input in the host computer terminal, including:

[0225] The attitude time series of the UAV during a certain mission segment (heading, pitch, roll changes over time).

[0226] The target orientation (azimuth and pitch of the target relative to the body coordinate system) or equivalent target orientation data within the corresponding task segment.

[0227] In the scenario and task editing module, the user creates "Task A (Flight Playback Calibration Task)" and configures it as follows:

[0228] The flight attitude data file and target orientation data file used;

[0229] Test start and end times, attitude sampling interval;

[0230] Selected two-dimensional launcher position conditions (e.g., selecting one or more typical target positions);

[0231] Signal source waveform parameters (consistent with the frequency band and mechanism of the actual flight mission).

[0232] Save task A after configuration.

[0233] 2. System initialization and robotic arm / launcher positioning

[0234] Before the experiment began:

[0235] The drive unit moves the standard gain horn antenna to one of the preset target positions and locks the position.

[0236] Return the FANUC six-axis robotic arm to a safe starting position and confirm that the head assembly is securely installed and the radome is intact.

[0237] The communication status between the host computer and the robotic arm controller, signal source, and direction finding equipment is normal.

[0238] In this embodiment, the robotic arm's base coordinate system is directly used as the reference coordinate system for the entire test scenario.

[0239] 3. Attitude trajectory generation and true orientation pre-calculation

[0240] The host computer's attitude and scene simulation module reads the actual flight attitude data from Task A and converts the UAV's body attitude point by point into the target attitude parameters (equivalent heading angle, pitch angle, and roll angle) of the nose assembly in the robotic arm coordinate system.

[0241] Meanwhile, based on the current position of the two-dimensional launcher and the position and attitude relationship of the nose assembly, the theoretical target incident azimuth and elevation angles corresponding to each time sampling point are calculated in advance to form a true direction time series table.

[0242] The motion control module generates the robotic arm's posture trajectory based on the target posture time series, and is prepared to gradually distribute it during the experimental execution phase.

[0243] 4. Attitude simulation execution and synchronous data acquisition

[0244] After starting Task A, the motion control module sends attitude commands to the robotic arm controller at predetermined time steps, causing the robotic arm to drive the head assembly to move along the actual flight attitude trajectory.

[0245] During this process:

[0246] The target signal source continuously or on demand transmits radar analog signals according to the waveform parameters configured for Mission A;

[0247] The airborne direction finding equipment operates normally inside the nose section, receiving and determining the direction of signals emitted by the target signal source in the anechoic chamber.

[0248] Data acquisition and calibration processing modules collect data synchronously:

[0249] a. Azimuth, elevation, and related status output by the direction finding equipment;

[0250] b. Posture information fed back by the robotic arm (used to confirm the actual execution trajectory);

[0251] c. The transmission status of the target signal source;

[0252] d. Current unified timestamp.

[0253] 5. Full-process recording under a unified time base

[0254] During the execution of Task A, the host computer software timestamps and manages the above-mentioned data based on a unified time base (host computer system time), forming a darkroom simulation record that corresponds one-to-one with the actual flight attitude data.

[0255] Simultaneously, at each time sampling point, the following can be obtained:

[0256] a. Actual nose posture (obtained through feedback calculations from the robotic arm);

[0257] b. The location of the corresponding target signal source;

[0258] c. The azimuth and elevation measurements output by the direction-finding equipment;

[0259] d. Pre-calculated theoretical true values ​​of azimuth and elevation.

[0260] 6. Solving for calibration parameters and verification through actual flight tests

[0261] After Task A is completed, the data acquisition and calibration processing module processes all the data from the simulation:

[0262] a. Compare the measurement results output by the direction finding device with the true direction point by point, and calculate the distribution of error as attitude and target direction change;

[0263] b. For attitude conditions where direction finding deviations or instability have occurred in actual flight tests, focus on analyzing the corresponding anechoic chamber simulation data to verify whether the problem can be successfully reproduced in the anechoic chamber;

[0264] c. Using methods such as multi-point fitting and piecewise interpolation, solve for the installation error correction parameters or azimuth / pitch correction tables, and generate a software configuration file that can be imported into the airborne direction finding system.

[0265] d. Users can update the parameters of the airborne direction finding equipment according to the calibration parameters. If necessary, they can repeat Task A or other simulation tasks in a darkroom to verify the calibration effect.

[0266] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computing software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. 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.

[0267] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0268] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A anechoic chamber calibration and attitude simulation system for airborne direction finding equipment, the system being used for testing, calibration, and attitude simulation of airborne direction finding equipment, characterized in that... include: Microwave anechoic chamber, attitude simulation mechanism, target simulation mechanism and host computer terminal; The microwave anechoic chamber is used to provide a low-reflection, low-interference electromagnetic environment and serves as a reference space for establishing the anechoic chamber coordinate system. The attitude simulation mechanism includes a six-degree-of-freedom robotic arm and a direction-finding device support platform. The direction-finding device support platform holds the airborne direction-finding device in the microwave anechoic chamber, and the six-degree-of-freedom robotic arm performs precise movements in six degrees of freedom according to a set attitude trajectory to simulate the installation attitude of the airborne direction-finding device on the flight platform and the attitude changes generated when it moves with the flight platform. The target simulation mechanism includes a target signal source and a support device. The target signal source generates a test signal with controllable polarization and waveform characteristics, and the transmission direction of the test signal is adjusted based on the support device. The host computer terminal is used to configure and issue test and calibration tasks, and establish communication with the six-degree-of-freedom robotic arm, the airborne direction finding equipment, the target signal source and the support device to monitor, analyze and manage the system operation status and calibration results; The host computer terminal includes: The scenario and task editing module is used to receive calibration requirements and simulation scenario parameters input by the user and generate a list of test and calibration tasks. Each task includes at least the flight platform type, equipment installation parameters, flight attitude time series, flight trajectory data, target trajectory data, test time axis, target signal source working parameters, and task execution mode. The task execution mode includes attitude simulation mode and actual flight data playback mode. The attitude and scene simulation module is used to establish the geometric relationship between various coordinate systems based on the test and calibration task list, and to calculate the theoretical incident direction of the simulated target relative to the airborne direction finding equipment. The motion control module is used to convert the theoretical incident direction output by the attitude and scene simulation module into control commands for the attitude simulation mechanism and the target simulation mechanism, and send them to the corresponding devices through the communication interface; The data acquisition and calibration processing module is used to acquire the direction finding results output by the airborne direction finding equipment, the attitude information of the attitude simulation mechanism and the state information of the target simulation mechanism, calculate the direction finding error and generate corresponding calibration parameters. The status monitoring module is used to receive the operating status, current task progress and alarm information reported by the six-degree-of-freedom robotic arm, the target signal source, the support device and the airborne direction finding equipment, and to display them graphically. The results analysis and management module is used to perform offline analysis and evaluation of the calibration process data after the experiment, visualize the distribution of direction finding errors and the effectiveness of calibration parameters, and archive and manage the calibration results. Establishing the geometric relationships between various coordinate systems and calculating the theoretical incident direction of the simulated target relative to the airborne direction-finding equipment includes: It includes a geographic coordinate system for describing the location of the flight platform and the simulated target, an aircraft body coordinate system for describing the attitude of the flight platform, a direction finding equipment coordinate system for describing the pointing relationship of the airborne direction finding equipment, an anechoic chamber coordinate system for describing the physical arrangement of the microwave anechoic chamber, a robot arm base coordinate system for describing the installation attitude of the six-degree-of-freedom robot arm, and an end flange coordinate system for describing the attitude of the end flange of the six-degree-of-freedom robot arm. During the system debugging phase, the rigid transformation calibration of the darkroom coordinate system and the robotic arm base coordinate system, as well as the rigid transformation calibration of the direction finding equipment coordinate system and the end flange coordinate system, are completed. Based on the established rigid transformation relationship of the coordinate system, the bidirectional pose transformation between different coordinate systems is completed through the cascade operation of homogeneous transformation matrices. Based on the bidirectional pose transformation relationship between different coordinate systems, the absolute spatial position of the simulated target and the direction of the transmitting antenna in the anechoic chamber coordinate system are converted into the relative position and incident direction of the direction finding device relative to the phase center of the airborne direction finding device in the direction finding device coordinate system. Based on the axial definition of the coordinate system of the direction finding device, the incident direction of the simulated target relative to the phase center of the airborne direction finding device is decomposed into the theoretical azimuth angle and the theoretical pitch angle.

2. The anechoic chamber calibration and attitude simulation system for airborne direction finding equipment according to claim 1, characterized in that, The attitude and scene simulation module is also used to achieve: The flight attitude and target scene simulation function includes: based on the flight attitude time series, flight trajectory data, and target trajectory data provided by the scene and task editing module, and combined with the bidirectional pose transformation relationship between different coordinate systems, calculating the theoretical incident azimuth angle and theoretical incident pitch angle of the simulated target relative to the aircraft body coordinate system and the direction finding equipment coordinate system at each moment; The attitude mapping and inverse kinematics solution function includes: based on the bidirectional pose transformation relationship between different coordinate systems, mapping the desired pointing attitude in the coordinate system of the direction finding device to the coordinate system of the darkroom and the base coordinate system of the robot arm, and combining the kinematic model of the robot arm to solve the corresponding joint angle commands of the six-degree-of-freedom robot arm to form the attitude trajectory of the six-degree-of-freedom robot arm; The real-time control and synchronization function includes: sending attitude control commands to the attitude simulation mechanism and working status control commands to the target simulation mechanism under a unified time reference, while receiving corresponding real-time feedback information for deviation verification and dynamic compensation, so that the geometric relationship between the attitude of the six-degree-of-freedom robotic arm and the direction of the simulated target test signal is consistent with the issued task scenario.

3. The anechoic chamber calibration and attitude simulation system for airborne direction finding equipment according to claim 1, characterized in that, The data acquisition and calibration processing module is also used to achieve: The data acquisition function includes: receiving the direction finding results output by the airborne direction finding device through the first communication interface, and synchronously acquiring the attitude information of the attitude simulation mechanism, the status information of the target simulation mechanism, and the system time information based on a unified time reference, to ensure that the timestamps of various data are consistent; The true direction calculation function includes: based on the attitude information of the attitude simulation mechanism, the state information of the target simulation mechanism, and the bidirectional pose transformation relationship between each coordinate system, calculating the theoretical azimuth and theoretical pitch angles of the test signal corresponding to the simulated target incident in the coordinate system of the direction finding device, as the true direction finding value; The error calculation and calibration parameter solving function includes: comparing the direction finding results output by the airborne direction finding equipment with the true direction finding value, obtaining the direction finding error data under different postures of the six-degree-of-freedom robotic arm and under different directions of the transmitting antenna, and automatically solving the corresponding calibration parameters based on the set algorithm; The result storage and export function includes: storing the original measurement data, true values ​​of direction finding, error curves and corresponding calibration parameters of the airborne direction finding equipment in a local storage medium, and exporting them in a predetermined format.

4. The anechoic chamber calibration and attitude simulation system for airborne direction finding equipment according to claim 1, characterized in that, The attitude simulation mechanism is connected to the host computer terminal via a second communication interface, and is used for: Based on the control commands issued by the motion control module regarding the attitude simulation mechanism, the six-degree-of-freedom robotic arm is driven to move along the calculated attitude trajectory at a predetermined sampling period, so that the airborne direction finding equipment can reproduce the same attitude change process as the flight platform in the microwave anechoic chamber. The encoder collects the joint angles and end-effector poses of the six-degree-of-freedom robotic arm and feeds them back to the attitude and scene simulation module and the data acquisition and calibration processing module to calculate the real-time attitude of the airborne orientation finding device in the darkroom coordinate system.

5. The anechoic chamber calibration and attitude simulation system for airborne direction finding equipment according to claim 1, characterized in that, The target simulation mechanism is connected to the host computer terminal via a third communication interface, for the purpose of: Based on the control commands issued by the motion control module regarding the target simulation mechanism, the operating parameters of the target signal source are configured, and a test signal compatible with the operating frequency band of the airborne direction finding equipment is generated during the test; the azimuth and elevation angles of the transmitting antenna are adjusted by the support device to change the transmission direction of the test signal; The current operating mode and transmission status of the target signal source, as well as the attitude information of the support device, are fed back to the host computer terminal and recorded by the data acquisition and calibration processing module.

6. The anechoic chamber calibration and attitude simulation system for airborne direction finding equipment according to claim 1, characterized in that, Also includes: When the task execution mode is attitude simulation calibration mode, the host computer terminal configures the virtual flight task and target scene through the scene and task editing module; the attitude and scene simulation module generates control commands for the attitude simulation mechanism and the target simulation mechanism based on the virtual flight task and target scene; the motion control module executes the control commands for the attitude simulation mechanism and the target simulation mechanism in the microwave anechoic chamber, so that the airborne direction finding equipment reproduces the predetermined flight conditions; the data acquisition and calibration processing module calculates and outputs the corresponding calibration parameters. When the task execution mode is the real flight data playback mode, the host computer terminal imports the flight attitude, flight trajectory, and target trajectory data recorded in the real flight test of the flight platform. The attitude and scene simulation module generates the corresponding attitude and scene according to the real flight timeline of the flight platform. The motion control module drives the attitude simulation mechanism and the target simulation mechanism to replay the real flight conditions of the flight platform. The data acquisition and calibration processing module conducts multiple comparative tests with and without calibration parameters to verify the correction effect of the calibration parameters on the real flight scene of the flight platform.

7. The anechoic chamber calibration and attitude simulation system for airborne direction finding equipment according to claim 1, characterized in that, The host computer terminal also reserves an external communication interface for an external flight simulation system. The external communication interface includes at least one serial communication interface and one Ethernet interface. The host computer terminal receives flight mission planning and target scenario information provided by the external flight simulation system through the external communication interface and generates darkroom test scenarios online.

8. A darkroom calibration and attitude simulation system for airborne direction finding equipment according to any one of claims 1-7, characterized in that, The direction finding equipment carrier platform is equipped with a special clamp to maintain a stable and reliable installation relationship between the airborne direction finding equipment and the direction finding equipment carrier platform.

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