Self-adaptive correction method for phase-sweeping radan installation angle of swash plate machine

Abstract

The invention, which relates to the technical field of the radar system, discloses a swash plate machine phase-sweeping radan installation angle adaptive correction method comprising the following steps: acquiring three-axis attitude angle data of an installation reference surface, and synchronously acquiring azimuth angle rotation data of a radar antenna; based on the three-axis attitude angle data of the installation reference surface, establishing a coordinate transformation matrix from a radar antenna coordinate system to an inertial coordinate system, and mapping the three-axis attitude angle data of the installation reference surface to the inertial coordinate system; obtaining a beam scanning conical surface deviation angle according to the coordinate transformation matrix and azimuth angle rotation data of the radar antenna; generating antenna attitude correction according to the beam scanning conical surface deviation angle; and inputting the antenna attitude correction quantity into an antenna driving controller, adjusting the attitude of two axes of pitching and orientation of the antenna, and compensating the beam scanning conical surface deviation. According to the method, the precise coordinate transformation matrix and the angle difference compensation model are established, and the inertial measurement unit and a closed-loop feedback control mechanism are combined, so that the self-adaptive real-time correction of the mounting angle is realized.

Description

Technical Field

[0001] The invention relates to the technical field of radar systems, in particular to a method for adaptively correcting the installation angle of a swash plate phase scanning radar. Background Art

[0002] Swash plate phase scan radar generates a conical scanning beam through an inclined rotating antenna and is an important target tracking and search device. In practical applications, due to the incomplete horizontality of the installation reference surface, machining errors and complex environmental factors, the actual rotation axis of the antenna often deviates from the theoretical axis.

[0003] The existing radar installation angle calibration method mainly relies on manual measurement and fixed parameter compensation, which not only requires downtime, but also cannot adapt to dynamically changing installation errors. As modern radar systems continue to increase their requirements for beam pointing accuracy, traditional fixed compensation methods can no longer meet actual application needs. Summary of the invention

[0004] In view of the problems that the existing swash plate phase scanning radar installation angle calibration has insufficient accuracy, poor adaptability, insufficient real-time performance, etc., the present invention is proposed.

[0005] The technical problem to be solved by the present invention is how to achieve high-precision adaptive real-time correction of the installation angle of the swash plate phase scanning radar, so as to overcome the problems of insufficient accuracy and real-time performance in traditional calibration methods.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: The invention provides a method for adaptively correcting the installation angle of a swash plate phase-scan radar, which comprises the following steps: obtaining three-axis attitude angle data of an installation reference surface, and synchronously collecting azimuth rotation data of a radar antenna to form a data record sequence; establishing a coordinate transformation matrix from a radar antenna coordinate system to an inertial coordinate system based on the three-axis attitude angle data of the installation reference surface, and mapping the three-axis attitude angle data of the installation reference surface to the inertial coordinate system; calculating the spatial pointing angle of an antenna beam scanning cone in the inertial coordinate system according to the coordinate transformation matrix and the azimuth rotation data of the radar antenna, and obtaining a beam scanning cone deviation angle; constructing an angle difference compensation model between a beam scanning cone and a standard cone according to the beam scanning cone deviation angle, and generating an antenna attitude correction amount; inputting the antenna attitude correction amount into an antenna drive controller, adjusting the antenna pitch and azimuth two-axis attitudes, and compensating for the beam scanning cone deviation; recalculating the beam scanning cone deviation angle based on the adjusted antenna attitude, and completing the adaptive correction of the installation angle when the beam scanning cone deviation angle is less than a preset threshold.

[0007] As a preferred solution of the method for adaptively correcting the installation angle of the swash plate phase-scan radar of the present invention, forming a data recording sequence includes the following steps: selecting an installation point on the installation reference plane of the swash plate phase-scan radar, and fixing the inertial measurement unit at the installation point; using the inertial measurement unit to collect the roll angle data, pitch angle data and yaw angle data of the installation reference plane; combining the roll angle data, pitch angle data and yaw angle data to form the three-axis attitude angle data of the installation reference plane; starting the azimuth turntable of the radar antenna to collect the azimuth rotation data of the radar antenna; synchronously recording the three-axis attitude angle data and the azimuth rotation data of the installation reference plane to form a data recording sequence.

[0008] As a preferred solution of the method for adaptively correcting the installation angle of the swash plate phase-scan radar described in the present invention, the method includes: mapping the three-axis attitude angle data of the installation reference surface to the inertial coordinate system includes the following steps: constructing a roll angle rotation matrix, a pitch angle rotation matrix, and a yaw angle rotation matrix according to the three-axis attitude angle data of the installation reference surface respectively; performing matrix multiplication operations on the roll angle rotation matrix, the pitch angle rotation matrix, and the yaw angle rotation matrix in a preset order to obtain a coordinate transformation matrix; verifying the orthogonality of the coordinate transformation matrix by numerical calculation; establishing a reference vector of the radar antenna coordinate system, and expressing the three-axis attitude angle data of the installation reference surface as a three-dimensional vector in the radar antenna coordinate system; using the coordinate transformation matrix, performing a forward transformation calculation on the three-axis attitude angle data of the installation reference surface, and mapping the three-dimensional vector in the radar antenna coordinate system to the inertial coordinate system; normalizing the three-dimensional vector after the forward transformation to obtain a unit vector representation in the inertial coordinate system; and decomposing the unit vector into three-dimensional components of the inertial coordinate system.

[0009] As a preferred solution of the method for adaptively correcting the installation angle of the swash plate phase-scan radar described in the present invention, obtaining the deviation angle of the beam scanning cone includes the following steps: establishing a generatrix equation of the beam scanning cone according to the azimuth rotation data of the radar antenna; generating a beam scanning trajectory point set based on the generatrix equation, and mapping the beam scanning trajectory point set from the radar antenna coordinate system to the inertial coordinate system; establishing a standard cone equation in the inertial coordinate system; fitting the transformed beam scanning trajectory point set by the least squares method to obtain the actual beam scanning cone equation; calculating the axial deviation angle and radial deviation angle of the actual beam scanning cone relative to the standard cone; and performing weighted combination of the axial deviation angle and the radial deviation angle to obtain the beam scanning cone deviation angle.

[0010] As a preferred solution of the method for adaptively correcting the installation angle of the swash plate phase-scanned radar described in the present invention, generating the antenna attitude correction includes the following steps: constructing a compensation coefficient matrix based on the beam scanning cone deviation angle, and calculating the eigenvalues ​​and eigenvectors of the compensation coefficient matrix; using the eigenvectors to construct the orthogonal basis functions of the angle difference compensation model; projecting the beam scanning cone deviation angle on the orthogonal basis functions to obtain the projection coefficients; calculating the axial deviation component and radial deviation component of the beam scanning cone according to the projection coefficients; establishing an attitude angle compensation calculation equation based on the axial deviation component and the radial deviation component to generate the antenna attitude correction.

[0011] As a preferred scheme of the method for adaptively correcting the installation angle of the swash plate phase-scan radar described in the present invention, compensating the beam scanning cone deviation includes the following steps: converting the antenna attitude correction amount into a drive control instruction format; initializing the antenna drive controller according to the drive control instruction, and configuring the control parameters; based on the control parameters, planning the motion trajectories of the antenna pitch axis and azimuth axis, and determining the speed parameters, acceleration parameters and position parameters of the motor; based on the motion trajectory, controlling the pitch axis and azimuth axis in turn to perform attitude correction, and completing the sequential adjustment of the two-axis attitude; establishing a position feedback control mechanism to compensate for the accumulated error in the attitude correction process in real time; based on the execution result of the position feedback control mechanism, evaluating the pointing error of the beam scanning cone; when the pointing error of the beam scanning cone is stable within the allowable range, applying locking torque to the pitch axis driver and the azimuth axis driver to complete the antenna attitude correction.

[0012] As a preferred solution of the method for adaptively correcting the installation angle of the swash plate phase scanning radar of the present invention, the specific formula of the orthogonal basis function is as follows: in, is the pitch angle, is the azimuth, is the pitch angle after singular point processing, v 1x 、v 1y 、v 1z is the feature vector v 1 The components on the x, y, and z axes of the inertial coordinate system, v 2x 、v 2y 、v 2z is the feature vector v 2 Components on the x, y, and z axes of the inertial coordinate system.

[0013] The beneficial effects of the present invention are as follows: the present invention uses an inertial measurement unit to obtain the three-axis attitude angle data of the installation reference surface and establishes a coordinate transformation matrix, thereby realizing accurate mapping from the radar antenna coordinate system to the inertial coordinate system, thereby providing an accurate measurement reference for attitude correction; by calculating the beam scanning cone deviation angle and constructing a compensation model, accurate correction of the antenna attitude is realized, so that the deviation between the beam scanning cone and the standard cone is controlled within a smaller range; a dual-axis linkage compensation strategy based on PID control and a real-time position feedback mechanism are adopted to effectively suppress the cumulative error in the attitude correction process, thereby improving the system stability and control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 The framework flow chart of the adaptive correction method for the installation angle of the swash plate phase scanning radar.

[0016] Figure 2 This is the coordinate system transformation flow chart of the adaptive correction method for the installation angle of the swash plate phase scanning radar.

[0017] Figure 3 The flowchart of the calculation of the beam scanning cone deviation angle of the swash plate phase scanning radar installation angle adaptive correction method is shown. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0019] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0020] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0021] Example 1, reference Figure 1~Figure 3, which is the first embodiment of the present invention, and provides a method for adaptively correcting the installation angle of a phase-scanning radar of a swash plate machine. The framework flow chart is as follows Figure 1 As shown, including, S1: Acquire the three-axis attitude angle data of the installation reference surface, and synchronously collect the azimuth rotation data of the radar antenna to form a data recording sequence.

[0022] Specifically, the following steps are included: S1.1: Select the installation point on the installation reference plane of the swash plate phase scanning radar and fix the inertial measurement unit to the installation point with the positioning bolts.

[0023] It should be noted that during the installation process, a level and a micrometer are used to perform multi-point inspection to ensure that the measurement reference surface of the inertial measurement unit is aligned with the radar installation reference surface.

[0024] S1.2: Align the origin of the measurement coordinate system of the inertial measurement unit with the origin of the radar antenna coordinate system.

[0025] Specifically, the calibration and alignment includes the following steps: by installing a laser pointer at the origin of the antenna coordinate system and projecting the laser beam to the reference mark point of the inertial measurement unit, the position of the inertial measurement unit is adjusted using a micrometer and an angle ruler so that the laser point coincides with the mark, and at the same time, the three-dimensional horizontality is measured with a level and adjusted to within an error of 0.02 degrees. A high-precision theodolite is then used to measure the relative spatial position relationship and record the coordinate deviation. Finally, the compensation matrix is ​​calculated to correct the output data.

[0026] It should be noted that after completing the spatial position alignment, it is necessary to ensure that the three measurement axes of the inertial measurement unit are parallel to the corresponding axes of the radar antenna coordinate system. The angle between the axes of the two coordinate systems is measured by a high-precision theodolite and adjusted to a parallelism error of less than 0.01 degrees.

[0027] S1.3: Use the inertial measurement unit to collect the roll angle data, pitch angle data and yaw angle data of the installation reference surface.

[0028] Specifically, the inertial measurement unit contains a gyroscope sensor module, an accelerometer sensor module and a magnetic compass sensor module, which are used to collect the roll angle data, pitch angle data and yaw angle data of the installation reference surface respectively. Among them, the gyroscope sensor module uses a FOG fiber optic gyroscope, the accelerometer sensor module uses a MEMS device, and the magnetic compass sensor module uses a three-axis magnetoresistive sensor, and all sensor modules use a unified 100Hz sampling frequency.

[0029] S1.4: Combine the roll angle data, pitch angle data and yaw angle data to form the three-axis attitude angle data of the installation reference surface.

[0030] S1.5: Start the azimuth turntable of the radar antenna, control the radar antenna to rotate 360 ​​degrees at the set speed, and at the same time collect the azimuth rotation data of the radar antenna through the turntable encoder.

[0031] The sampling interval of the azimuth rotation data is 1 degree.

[0032] S1.6: Synchronously record the three-axis attitude angle data and azimuth rotation data of the installation reference surface to form a time-synchronized data recording sequence.

[0033] Specifically, a unified time base is used to align the 100 Hz attitude angle data with the 1 degree interval azimuth data through interpolation to ensure the time consistency of the data recording sequence.

[0034] S1.7: Perform digital filtering on the data record sequence to remove measurement noise and interference signals.

[0035] S1.8: The filtered three-axis attitude angle data and azimuth rotation data of the installation reference surface are stored in the data buffer area.

[0036] S2: Based on the three-axis attitude angle data of the installation reference surface, a coordinate transformation matrix from the radar antenna coordinate system to the inertial coordinate system is established to map the three-axis attitude angle data of the installation reference surface to the inertial coordinate system.

[0037] Specifically, the coordinate system transformation flow chart is as follows Figure 2 As shown, the following steps are included: S2.1: According to the three-axis attitude angle data of the installation reference surface, the roll angle rotation matrix, the pitch angle rotation matrix, and the yaw angle rotation matrix are constructed respectively.

[0038] Specifically, three basic rotation matrices are constructed based on the Euler angle definition, where the roll angle rotation matrix represents the rotation transformation relationship of the radar antenna coordinate system around the X-axis, the pitch angle rotation matrix represents the rotation transformation relationship of the radar antenna coordinate system around the Y-axis, and the yaw angle rotation matrix represents the rotation transformation relationship of the radar antenna coordinate system around the Z-axis.

[0039] During the construction process, the actual operating range of the radar system is taken into consideration. When the roll and pitch angles are within the range of ±30 degrees, selecting the ZYX sequence can effectively avoid the gimbal deadlock problem.

[0040] S2.2: Perform matrix multiplication operation on the roll angle rotation matrix, the pitch angle rotation matrix, and the yaw angle rotation matrix in the order of ZYX to obtain a 3×3 coordinate transformation matrix.

[0041] S2.3: Verify the orthogonality of the coordinate transformation matrix through numerical calculations.

[0042] It should be noted that in order to ensure the reversibility of the coordinate transformation, the determinant value of the coordinate transformation matrix R must be 1.

[0043] S2.4: Establish a reference vector in the radar antenna coordinate system, and express the three-axis attitude angle data of the installation reference surface as a three-dimensional vector in the radar antenna coordinate system.

[0044] The reference vector includes a normal direction component and an in-plane direction component of the installation reference surface, and each component of the three-dimensional vector corresponds to a projection of the installation reference surface on the three-dimensional coordinate axis.

[0045] Specifically, the steps to establish the reference vector in the radar antenna coordinate system are as follows: First, define the three reference vectors of the radar antenna coordinate system, including the X-axis reference vector [1, 0, 0] T , Y-axis reference vector [0, 1, 0] T and the Z-axis reference vector [0, 0, 1] T ; Then, according to the normal direction of the installation reference plane, determine the projection vector of this direction in the radar antenna coordinate system, recorded as the normal projection vector n; then select any direction in the installation reference plane as the in-plane reference direction of the installation reference plane, and determine the projection vector of this direction in the radar antenna coordinate system, recorded as the in-plane reference projection vector m; then, through the vector cross multiplication operation, cross multiply the normal projection vector n with the in-plane reference projection vector m to obtain the orthogonal reference projection vector b; finally, n, m, and b are normalized to form a standard orthogonal basis in the radar antenna coordinate system.

[0046] S2.5: Use the coordinate transformation matrix to perform forward transformation calculation on the three-axis attitude angle data of the installation reference surface, and map the three-dimensional vector in the radar antenna coordinate system to the inertial coordinate system.

[0047] Specifically, the normal projection vector n, the in-plane reference projection vector m, and the orthogonal reference projection vector b are represented as a 3×3 reference vector matrix; the coordinate transformation matrix and the reference vector matrix are multiplied to obtain the representations n', m', and b' of the three projection vectors in the inertial coordinate system; it is verified whether the three projection vectors n', m', and b' after the transformation still maintain orthogonality, and at the same time, it is verified whether the modulus length of the three projection vectors after the transformation is 1.

[0048] S2.6: Normalize the three-dimensional vector after the forward transformation to eliminate the influence of the scale factor and obtain the unit vector representation in the inertial coordinate system.

[0049] S2.7: Decompose the unit vector into its three components in the east-north-south direction of the inertial coordinate system.

[0050] S3: According to the coordinate transformation matrix and the azimuth rotation data of the radar antenna, the spatial pointing angle of the antenna beam scanning cone in the inertial coordinate system is calculated to obtain the beam scanning cone deviation angle.

[0051] Specifically, the calculation flow chart of the beam scanning cone deviation angle is as follows: Figure 3 As shown, the following steps are included: S3.1: Based on the azimuth rotation data of the radar antenna, establish the generatrix equation of the beam scanning cone.

[0052] The busbar equation describes the spatial pointing characteristics of the antenna beam in the radar antenna coordinate system. The establishment process is as follows: Take the coincidence of the antenna rotation axis and the Z axis of the radar antenna coordinate system as the initial position and establish the parametric equation: ,in is any angle value within the azimuth rotation range, and its value range is [0, 2 ], The beam deflection angle is 45 degrees.

[0053] S3.2: Generate a beam scanning trajectory point set based on the generatrix equation, and map the beam scanning trajectory point set from the radar antenna coordinate system to the inertial coordinate system.

[0054] Specifically, the generatrix equation of the beam scanning cone is discretized and sampled at preset angle intervals to obtain multiple sampling points, wherein each sampling point corresponds to an angle position in the azimuth rotation data, forming a beam scanning trajectory point set.

[0055] In this embodiment, the preset angle interval is 1 degree, that is, the 360-degree azimuth rotation range is equally divided into 360 sampling points.

[0056] S3.3: Establish the equation of the standard cone in an inertial coordinate system.

[0057] Specifically, the process of establishing the standard cone surface equation is as follows: the cone surface with the Z axis as the axis and a cone angle of 45 degrees is expressed as ; Calculate the vertical distance from each point in the transformed beam scanning trajectory point set to the standard cone surface; Evaluate the systematic error of beam scanning based on the mean vertical distance, and evaluate the random error based on the standard deviation of the vertical distance.

[0058] S3.4: Fit the transformed beam scanning trajectory point set by the least squares method to obtain the actual beam scanning cone equation.

[0059] Specifically, construct the least squares objective function ,in is the coordinate of the trajectory point; find the partial derivative of the objective function and set it to 0, and get the normal vector [abc] and the intercept d; express the fitting result as the plane beam equation ax+by+cz+d=0, where a, b, c represent the normal vector components of the cone surface in the inertial coordinate system, and satisfy the normalization condition a 2 +b 2 +c 2 =1, the plane beam equation describes the spatial geometric characteristics of the actual beam scanning cone.

[0060] S3.5: Calculate the axial deviation angle and radial deviation angle of the actual beam scanning cone relative to the standard cone.

[0061] Specifically, the axial deviation angle is obtained by calculating the angle between the axial direction cosine of the actual beam scanning cone and the axis of the standard cone. The specific steps are as follows: normalize the normal vector [abc] in the plane beam equation ax+by+cz+d=0 to obtain the unit normal vector u; calculate the angle between the unit normal vector u and the unit vector [0 0 1] of the Z axis of the inertial coordinate system to obtain the deviation angle of the actual beam scanning cone axis relative to the standard cone axis.

[0062] Furthermore, the difference in cone angle between the actual beam scanning cone and the standard cone is calculated by spherical geometry to obtain the radial deviation angle. The specific steps are as follows: M sampling points are uniformly selected on the actual beam scanning cone, where M is 360; the angle between each sampling point and the axis of the cone is calculated; the actual cone angle is obtained by averaging all the angles; the difference between the actual cone angle and the nominal cone angle of 45 degrees is calculated to obtain the radial deviation angle.

[0063] S3.6: Perform a weighted combination of the axial deviation angle and the radial deviation angle to obtain the beam scanning cone deviation angle.

[0064] The beam scanning cone deviation angle represents the comprehensive deviation degree of the actual beam scanning cone relative to the standard cone. In this embodiment, the weight coefficient of the axial deviation angle is set to w 1 =0.7, the weight coefficient of the radial deviation angle is set to w 2 = 0.3, the sum of weight coefficients satisfies w 1 +w 2 =1, the setting of the weight coefficient takes into account the main influence of the axial deviation on the antenna beam pointing accuracy.

[0065] S4: According to the deviation angle of the beam scanning cone, a compensation model for the angle difference between the beam scanning cone and the standard cone is constructed to generate the antenna attitude correction value.

[0066] Specifically, the following steps are included: S4.1: Construct a compensation coefficient matrix based on the beam scanning cone deviation angle, and calculate the eigenvalues ​​and eigenvectors of the compensation coefficient matrix.

[0067] The compensation coefficient matrix includes axial compensation coefficients and radial compensation coefficients, the eigenvector indicates the main direction of the beam scanning cone deviation, and the eigenvalue represents the weight of the deviation in each direction. In addition, the axial compensation coefficient and radial compensation coefficient correspond to the correction weights of the cone axial deviation and cone angle deviation, respectively.

[0068] S4.2: Use the eigenvectors to construct the orthogonal basis functions of the angle difference compensation model.

[0069] Furthermore, the eigenvectors are projected onto the coordinate plane of the inertial coordinate system to generate mutually orthogonal basis functions, where the basis functions are used to decompose the spatial deviation components of the beam scanning cone. The construction process is as follows: Based on the eigenvalue decomposition obtained, the eigenvector v 1 、v 2 , after coordinate transformation, we get the orthogonal basis functions in the inertial system: in, is the pitch angle, is the azimuth, is the pitch angle after singular point processing, v 1x 、v 1y 、v 1z is the feature vector v 1 The components on the x, y, and z axes of the inertial coordinate system, v 2x 、v 2y 、v 2z is the feature vector v 2 Components on the x, y, and z axes of the inertial coordinate system.

[0070] also, , express The symbol function of .

[0071] S4.3: Project the beam scanning cone deviation angle onto the orthogonal basis function to obtain the projection coefficient.

[0072] First, according to the spatial position relationship between the beam scanning cone and the standard cone, the beam scanning cone deviation angle distribution function is constructed. , which describes the pitch angle and azimuth The angular deviation of the beam scanning cone relative to the standard cone at a certain point in space.

[0073] Furthermore, the calculation process of the projection coefficient is as follows: the corresponding projection coefficient is obtained by performing an inner product operation on the beam scanning cone deviation angle distribution function and the orthogonal basis function and normalizing the result. To improve the calculation efficiency, the discrete grid summation is used instead of the continuous integral calculation, and the projection coefficient of each basis function direction is obtained by the local weighted average within the grid. The projection coefficient reflects the degree of deviation of the beam scanning cone relative to the standard cone in different basis function directions.

[0074] S4.4: Calculate the axial deviation component and the radial deviation component of the beam scanning cone based on the projection coefficients.

[0075] Specifically, the axial deviation component and radial deviation component The calculation formula is: in, is the eigenvalue of the compensation coefficient matrix C, is the angle between the cone’s central axis and the ground plane, is the coupling coefficient of axial deviation and radial deviation, and its value range is [0, 1]. is the projection coefficient.

[0076] S4.5: Establish an attitude angle compensation calculation equation based on the axial deviation component and the radial deviation component to generate the antenna attitude correction value.

[0077] Specifically, the attitude angle compensation calculation equation adopts the PID control structure: in, is the pitch angle correction, is the azimuth correction, are the pitch angle proportional coefficient, pitch angle integral coefficient, and pitch angle differential coefficient, are the azimuth proportional coefficient, azimuth integral coefficient, and azimuth differential coefficient, t is the time variable, is the axial deviation component, is the radial deviation component.

[0078] It should be noted that based on the fuzzy control rules, a PID parameter adaptive adjustment mechanism is established: the fuzzy set of error and error change rate is defined, and a fuzzy rule base is established; according to the real-time error size and change trend, the PID parameter adjustment amount is calculated through fuzzy reasoning, where the parameter adjustment range is: K p ±20%, K i ±30%, Kd ±25%; establish parameter adjustment history records for optimizing control strategies.

[0079] S4.6: Design a nonlinear mapping function to map the antenna attitude correction to the actual motion range of the antenna drive mechanism.

[0080] In this embodiment, the nonlinear mapping function takes the form of an adjustable hyperbolic tangent function.

[0081] S5: Input the antenna attitude correction value to the antenna drive controller to adjust the antenna pitch and azimuth attitudes to compensate for the beam scanning cone deviation.

[0082] Specifically, the following steps are included: S5.1: Convert the antenna attitude correction value into a drive control instruction format for subsequent execution of the drive controller.

[0083] S5.2: Initialize the antenna drive controller according to the drive control instruction and configure the control parameters.

[0084] The control parameters include communication parameters, drive mode and motion parameters, which are used to ensure the normal operation of the drive controller.

[0085] S5.3: Based on the control parameters, plan the motion trajectory of the antenna pitch axis and azimuth axis, and determine the speed parameters, acceleration parameters and position parameters of the motor.

[0086] Specifically, the motion trajectory planning process is as follows: first, the maximum motion speed and maximum acceleration are set based on the correction value; second, the trapezoidal velocity curve is used for trajectory planning, including acceleration segment, uniform speed segment and deceleration segment, in which the acceleration segment and deceleration segment use cosine function for smooth transition to ensure a smooth motion process; finally, the expected position, velocity and acceleration parameters at each time point are calculated according to the planning curve.

[0087] S5.4: Based on the motion trajectory, the pitch axis and the azimuth axis are controlled in turn to perform attitude correction, completing the sequential adjustment of the two-axis attitude.

[0088] Specifically, according to the motion trajectory, the speed, acceleration and position parameters of the pitch axis driver are set to the corresponding expected values ​​in the motion trajectory, the pitch axis driver is controlled to perform the first stage correction action, and the position error of the pitch axis is monitored through encoder feedback; when the position error of the pitch axis reaches a predetermined position, the motion parameters of the azimuth axis driver are set to the expected values ​​of the motion trajectory, and the azimuth axis driver is controlled to perform the second stage correction action, thereby realizing sequential adjustment of the two-axis attitude.

[0089] It should be noted that the first-stage correction action and the second-stage correction action are determined based on the vector decomposition of the correction amount. The total correction amount is decomposed into the components of the pitch axis and the azimuth axis, and the axial correction with the larger component is performed first, and is executed according to the motion trajectory planned in S5.3. The predetermined position refers to a position error less than 0.01 degrees.

[0090] S5.5: Establish a position feedback control mechanism to compensate for the accumulated error in the attitude correction process in real time.

[0091] Specifically, during the execution of the correction action, the antenna attitude sensor data is collected, a real-time position feedback loop is established, and the drive control command is dynamically adjusted through the PID control algorithm, as follows: a cascade PID control structure is adopted, with the outer loop being the position loop and the inner loop being the speed loop. The position loop calculates the position error by comparing the actual position with the expected position of the motion trajectory; the speed loop calculates the speed error by comparing the actual speed with the expected speed of the trajectory planning. The output of the position loop is used as the speed given value, and is superimposed with the expected speed value of the motion trajectory and then input into the speed loop; the speed loop output is superimposed with the feedforward acceleration of the motion trajectory to form the final torque command.

[0092] Furthermore, the current parameters and speed parameters of the pitch-axis driver and the azimuth-axis driver are monitored; based on the real-time position feedback loop, current parameters and speed parameters, a linkage compensation strategy for the antenna pitch axis and azimuth axis is established, the deviation between the actual motion trajectory of the two axes and the planned trajectory is compared, and the position parameters of the pitch-axis driver are fine-tuned in real time during the rotation of the azimuth-axis driver.

[0093] S5.6: Based on the execution results of the position feedback control mechanism, the pointing error of the beam scanning cone is evaluated and the antenna attitude correction is completed.

[0094] Specifically, when the pointing error of the beam scanning cone is stable within the allowable range, the locking torque is applied to the pitch axis driver and the azimuth axis driver to complete the antenna attitude correction. The allowable range is determined by the system indicator requirements, specifically the root mean square deviation between the actual trajectory and the planned trajectory is less than 0.02 degrees, and stability means that the trajectory deviation fluctuation range within 20 consecutive sampling cycles is less than 0.005 degrees.

[0095] S6: recalculate the beam scanning cone deviation angle based on the adjusted antenna posture, and when the beam scanning cone deviation angle is less than a preset threshold, complete the adaptive correction of the installation angle.

[0096] It should be noted that the preset threshold is determined by the antenna beam pointing accuracy and other system technical indicators. When the beam scanning cone deviation angle calculated three times in a row is less than the preset threshold, it is considered that the adaptive correction of the installation angle is completed. If the beam scanning cone deviation angle is greater than the preset threshold, it is necessary to return to the attitude correction process in S5 until the accuracy requirement is met.

[0097] In summary, the present invention obtains the three-axis attitude angle data of the installation reference surface by adopting an inertial measurement unit and establishes a coordinate transformation matrix, thereby realizing the precise mapping from the radar antenna coordinate system to the inertial coordinate system, thereby providing an accurate measurement reference for attitude correction; by calculating the beam scanning cone deviation angle and constructing a compensation model, the antenna attitude is accurately corrected, so that the deviation between the beam scanning cone and the standard cone is controlled within a smaller range; the dual-axis linkage compensation strategy based on PID control and the real-time position feedback mechanism are adopted to effectively suppress the cumulative error in the attitude correction process, and improve the system stability and control accuracy.

[0098] Example 2, reference Figure 1~Figure 3 , which is the second embodiment of the present invention, provides a method for adaptively correcting the installation angle of a phase-scan radar of a swash plate machine. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0099] In order to verify the effectiveness of the proposed adaptive correction method for the installation angle of the swash plate phased array radar, an experimental verification was carried out on a certain type of S-band phased array radar system. The experimental platform uses a fiber optic gyro inertial measurement unit, the sampling frequency is set to 100Hz, and the measurement accuracy is better than 0.01°. During the experiment, the rotation speed of the radar antenna azimuth turntable is set to 30° / s, the rotation range is 0°~360°, and the sampling interval is 1°.

[0100] During the initial installation phase, a laser tracker was used to measure the installation reference surface, and the radar antenna installation reference surface was measured to have a roll angle deviation of -0.156°, a pitch angle deviation of 0.213°, and a yaw angle deviation of 0.178°. Multi-point detection was performed using a micrometer and a level to ensure that the fit error between the inertial measurement unit and the radar installation reference surface was less than 0.02mm. The relative position relationship between the inertial measurement unit and the origin of the radar antenna coordinate system was measured using a theodolite, and the recorded coordinate deviations were ΔX=-0.025mm, ΔY=0.031mm, and ΔZ=0.018mm.

[0101] During the data collection phase, the system continuously recorded 10 antenna rotation data. After digital filtering, the standard deviations of the three-axis attitude angle data of the installation reference plane were obtained: roll angle 0.0085°, pitch angle 0.0092°, yaw angle 0.0078°. The attitude data was fused based on the extended Kalman filter algorithm, the filter convergence time was 0.8s, and the attitude estimation accuracy was better than 0.01°.

[0102] The coordinate transformation matrix is ​​constructed using the ZYX sequence Euler angle representation. The matrix determinant value obtained through numerical verification is 0.9998, which meets the orthogonality requirement. In the inertial coordinate system, the actual measurement data of the beam scanning cone surface shows that there is an axial deviation angle of 0.385° and a radial deviation angle of 0.267° relative to the standard 45° cone surface. Based on the weight coefficients of 0.7 and 0.3, the calculated comprehensive beam scanning cone surface deviation angle is 0.348°.

[0103] Through comparative analysis, the performance parameters of the method of the present invention and several existing typical installation angle correction methods are shown in Table 1: Table 1 Performance parameters of the method of the present invention and several existing typical installation angle correction methods It can be seen from Table 1 that, compared with the prior art, the method of the present invention has obvious advantages in key performance indicators such as attitude measurement accuracy, correction time, and deviation residual. In particular, the correction time is shortened by more than 80%, while maintaining a high environmental adaptability.

[0104] During the attitude correction execution phase, the system uses a trapezoidal velocity curve for trajectory planning. The maximum velocity of the pitch and azimuth axes is set to 2° / s, and the maximum acceleration is 1° / s. 2 . Position closed-loop control is achieved through cascade PID control, with the bandwidth of the outer loop position control being 2Hz and the bandwidth of the inner loop speed control being 20Hz. After 5 minutes of iterative correction, the system finally reached a stable state, with the axial deviation of the corrected beam scanning cone reduced to 0.052°, the radial deviation reduced to 0.043°, and the comprehensive deviation angle reduced to 0.049°, meeting the system index requirements.

[0105] In the stability test after the correction, the system ran continuously for 24 hours, and the beam scanning cone deviation data was recorded every hour. The statistical results show that the attitude angle drift after correction is less than 0.008° / h, the beam pointing accuracy is better than 0.05°, and the system stability is good. The temperature change test (-20℃~50℃) shows that during the temperature change process, the change in the beam scanning cone deviation does not exceed 0.015°, which verifies that the method has good environmental adaptability.

[0106] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for adaptively correcting the installation angle of a swash plate phase scanning radar, characterized in that: include, Acquire the three-axis attitude angle data of the installation reference surface, and synchronously collect the azimuth rotation data of the radar antenna to form a data recording sequence; Based on the three-axis attitude angle data of the installation reference surface, a coordinate transformation matrix from the radar antenna coordinate system to the inertial coordinate system is established to map the three-axis attitude angle data of the installation reference surface to the inertial coordinate system; Calculate the spatial pointing angle of the antenna beam scanning cone in the inertial coordinate system according to the coordinate transformation matrix and the azimuth rotation data of the radar antenna to obtain the beam scanning cone deviation angle; According to the beam scanning cone deviation angle, a compensation model for the angle difference between the beam scanning cone and the standard cone is constructed to generate an antenna attitude correction value; Inputting the antenna attitude correction value into the antenna drive controller to adjust the antenna pitch and azimuth attitudes to compensate for the beam scanning cone deviation; The beam scanning cone deviation angle is recalculated based on the adjusted antenna posture, and when the beam scanning cone deviation angle is less than a preset threshold, the installation angle adaptive correction is completed.

2. The method for adaptively correcting the installation angle of the swash plate phase scanning radar according to claim 1, characterized in that: The forming of the data record sequence comprises the following steps: Selecting an installation point on the installation reference plane of the swash plate phase scanning radar, and fixing the inertial measurement unit to the installation point; Using the inertial measurement unit, collecting roll angle data, pitch angle data and yaw angle data of the installation reference surface; Combining the roll angle data, the pitch angle data and the yaw angle data to form three-axis attitude angle data of the installation reference plane; Start the azimuth turntable of the radar antenna to collect the azimuth rotation data of the radar antenna; The three-axis attitude angle data of the installation reference surface and the azimuth rotation data are synchronously recorded to form a data recording sequence.

3. The method for adaptively correcting the installation angle of the swash plate phase scanning radar according to claim 1, characterized in that: Mapping the three-axis attitude angle data of the installation reference surface to the inertial coordinate system comprises the following steps: According to the three-axis attitude angle data of the installation reference surface, a roll angle rotation matrix, a pitch angle rotation matrix, and a yaw angle rotation matrix are constructed respectively; Perform matrix multiplication operation on the roll angle rotation matrix, the pitch angle rotation matrix, and the yaw angle rotation matrix in a preset order to obtain a coordinate transformation matrix; Verifying the orthogonality of the coordinate transformation matrix by numerical calculation; Establishing a reference vector of the radar antenna coordinate system, and expressing the three-axis attitude angle data of the installation reference surface as a three-dimensional vector in the radar antenna coordinate system; Using the coordinate transformation matrix, forward transformation calculation is performed on the three-axis attitude angle data of the installation reference surface to map the three-dimensional vector in the radar antenna coordinate system to the inertial coordinate system; Normalize the three-dimensional vector after the forward transformation to obtain the unit vector representation in the inertial coordinate system; Decompose the unit vector into its three-dimensional components in the inertial coordinate system.

4. The method for adaptively correcting the installation angle of the swash plate phase scanning radar according to claim 1, characterized in that: The obtaining of the beam scanning cone deviation angle comprises the following steps: According to the azimuth rotation data of the radar antenna, a generatrix equation of the beam scanning cone is established; Generate a beam scanning trajectory point set based on the generatrix equation, and map the beam scanning trajectory point set from the radar antenna coordinate system to the inertial coordinate system; Establish the standard cone equation in the inertial coordinate system; The transformed beam scanning trajectory point set is fitted by the least square method to obtain the actual beam scanning cone equation; Calculate the axial deviation angle and radial deviation angle of the actual beam scanning cone surface relative to the standard cone surface; The axial deviation angle and the radial deviation angle are weightedly combined to obtain the beam scanning cone deviation angle.

5. The method for adaptively correcting the installation angle of the swash plate phase scanning radar according to claim 1, characterized in that: Generating the antenna attitude correction comprises the following steps: Constructing a compensation coefficient matrix based on the beam scanning cone deviation angle, and calculating the eigenvalues ​​and eigenvectors of the compensation coefficient matrix; Using the eigenvectors to construct orthogonal basis functions of an angle difference compensation model; Projecting and decomposing the beam scanning cone deviation angle on the orthogonal basis function to obtain a projection coefficient; Calculating the axial deviation component and the radial deviation component of the beam scanning cone according to the projection coefficient; An attitude angle compensation calculation equation is established based on the axial deviation component and the radial deviation component to generate an antenna attitude correction value.

6. The method for adaptively correcting the installation angle of the swash plate phase scanning radar according to claim 1, characterized in that: The compensation of the beam scanning cone deviation comprises the following steps: Convert antenna attitude correction into drive control instruction format; Initialize the antenna drive controller and configure control parameters according to the drive control instruction; Based on the control parameters, the motion trajectories of the antenna pitch axis and azimuth axis are planned, and the speed parameters, acceleration parameters and position parameters of the motor are determined; Based on the motion trajectory, the pitch axis and the azimuth axis are sequentially controlled to perform attitude correction, thereby completing the sequential adjustment of the attitude of the two axes; Establish a position feedback control mechanism to compensate for the accumulated error in the posture correction process in real time; Based on the execution result of the position feedback control mechanism, evaluating the pointing error of the beam scanning cone; When the pointing error of the beam scanning cone is stabilized within an allowable range, a locking torque is applied to the pitch axis driver and the azimuth axis driver to complete the antenna attitude correction.

7. The method for adaptively correcting the installation angle of the swash plate phase scanning radar according to claim 5, characterized in that: The specific formula of the orthogonal basis function is as follows: in, is the pitch angle, is the azimuth, is the pitch angle after singular point processing, v 1x 、v 1y 、v 1z is the component of the eigenvector v1 on the x, y, and z axes of the inertial coordinate system, v 2x 、v 2y 、v 2z are the components of the eigenvector v2 on the x, y, and z axes of the inertial coordinate system.

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