A communication antenna steering control system and method

Abstract

The application provides a communication antenna steering control system and method, and relates to the technical field of antenna control, and comprises the following: a parameter configuration module, which is used for acquiring the initial state of a communication antenna and collecting hardware state information in real time; a signal capture and tracking module, which is used for configuring the initial frequency of a digital control oscillator, starting a parallel correlator group to scan the carrier frequency, and calculating frequency domain power spectrum data; and an angle calculation module, which maps the resampling phase difference and baseline parameters to an azimuth angle based on quaternion solution, and superimposes IMU angular velocity data for dynamic compensation. The application realizes high sensitivity capture of signals in a wide frequency band by adopting a multi-stage phase-locked loop architecture, a dynamic threshold adaptive algorithm, a cascaded frequency division coefficient compensation and a FIR comb filter; greatly reduces the phase lag of a steering engine system by fusing extended Kalman filtering and mechanical hysteresis compensation algorithms; and makes the system still maintain high pointing accuracy in a dynamic scene by combining real-time fusion of IMU angular velocity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antenna control, and in particular to a communication antenna steering control system and method. BACKGROUND

[0002] A communication antenna is a core device for realizing the mutual conversion of radio waves and guided electromagnetic waves, and its technical development is closely related to electromagnetic theory, material science and communication demand. Since the end of the 19th century when Hertz verified the existence of electromagnetic waves, as the physical interface of wireless systems, antennas have undergone evolution from early dipole, monopole and other basic structures to multi-element forms. In the 20th century, with the popularity of short-wave communication, broadcast television and radar systems, antenna design gradually formed key technology systems such as frequency band adaptation and direction characteristic regulation, giving rise to various forms such as parabolic antennas, microstrip antennas and spiral antennas. The iteration of modern communication technology has promoted antennas to develop in the direction of high frequency band (millimeter wave), miniaturization and multi-band compatibility, and the progress of integrated circuit technology and 3D printing technology has promoted the realization of new structures such as reconfigurable antennas and metasurface antennas. Currently, antenna technology has been deeply integrated into mobile communication (such as 5G MIMO), satellite communication (low-orbit constellation networking) and Internet of Things (low-power wide-area network) fields, and has become a basic element supporting wireless information interaction.

[0003] Communication antenna steering control refers to the technology of adjusting the antenna radiation direction or beam pointing through mechanical or electronic means, and its core lies in optimizing signal reception / transmission efficiency, coverage range and anti-interference capability. This technology originated from the demand for directional transmission in early radio communication and gradually developed with the evolution of antenna theory and control systems. In the mechanical steering stage, the physical rotation of the antenna driven by the motor realizes the adjustment of the azimuth angle, but it is limited by mechanical wear, response speed and precision problems. In the mid-20th century, the emergence of phased array technology made it possible to control the beam steering electronically, and by using phase shifters to adjust the phase difference of array elements, electronic scanning without mechanical movement was realized, significantly improving the control flexibility and multi-target tracking capability.

[0004] In general, the communication antenna steering control system uses a traditional single-stage phase-locked loop architecture for signal acquisition, which has a large number of frequency multiplication times, resulting in phase noise accumulation and making it difficult to achieve wideband high-sensitivity signal acquisition. Moreover, mechanical hysteresis compensation is usually not performed, resulting in a high amount of phase lag. The system has a slow response speed to large angle deviations.

[0005] To solve the above-mentioned defects in the prior art, the present technical solution proposes a communication antenna steering control system and method. SUMMARY

[0006] The present application provides a communication antenna steering control system and method to solve the defects in the prior art.

[0007] In one aspect, the application provides a communication antenna steering control system, comprising:

[0008] A parameter configuration module is configured to obtain an initial state of the communication antenna, output a calibration parameter package, and collect hardware state information in real time through an SPI bus;

[0009] A signal capture and tracking module is configured to configure an initial frequency of a digital control oscillator according to the calibration parameter package, start a parallel correlator group to scan a carrier frequency, and calculate frequency domain power spectrum data; when the frequency domain power spectrum data exceeds a preset dynamic threshold, the signal capture and tracking module is configured to switch to a tracking mode, output a phase difference sequence through a FIR filter;

[0010] A time synchronization module is configured to associate the phase difference sequence with a synchronization trigger signal using a time stamp associator to map phase data and attitude data in the hardware state information to a unified time reference, and output a resampled phase difference;

[0011] An angle calculation module is configured to map the resampled phase difference and baseline parameters to an azimuth angle based on a quaternion solution, superimpose IMU angular velocity data for dynamic compensation, and output an estimated azimuth angle;

[0012] A steering control module is configured to calculate a deviation between the estimated azimuth angle and a target pointing angle, and generate a torque instruction through a sliding mode controller;

[0013] A steering engine driving module is configured to generate a PWM waveform to drive a motor through an HRTimer according to the torque instruction.

[0014] According to the communication antenna steering control system provided by the application, the signal capture and tracking module comprises:

[0015] A parameter initialization unit is configured to set a frequency division coefficient of the digital control oscillator according to the calibration parameter package, initialize a correlator group register, and output a correlator group initialization completion signal;

[0016] A parallel correlator unit is configured to perform carrier frequency band scanning through a four-channel DDC according to the initialization completion signal and the hardware state information, and calculate frequency domain power spectrum data;

[0017] A detection switching unit is configured to trigger mode switching by comparing the frequency domain power spectrum data with a preset threshold, and output a mode control signal;

[0018] A tracking processing unit is configured to run a frequency-locked loop-phase-locked loop joint algorithm in combination with the mode control signal and the frequency domain power spectrum data, and output a phase difference sequence through a FIR comb filter.

[0019] According to the communication antenna steering control system provided by the application, the step of outputting the phase difference sequence comprises:

[0020] The analysis mode control signal is analyzed to determine that the current mode is a tracking mode; a carrier frequency offset and real-time noise power in frequency domain power spectrum data are extracted, and a tracking mode parameter package is output;

[0021] A frequency error is calculated according to the tracking mode parameter package and the calibration parameter package, and a second-order frequency-locked loop algorithm is run according to the frequency error, and a frequency control word is output;

[0022] The frequency of a digital controlled oscillator is adjusted according to the frequency control word, so that the signal enters a PLL locking bandwidth, and a frequency-locked baseband signal is output;

[0023] A phase error is calculated according to the frequency-locked baseband signal, and a third-order phase-locked loop algorithm is run, and a phase control word is output;

[0024] A quadrature local carrier signal is generated according to the phase control word, and is mixed with the input signal, and a phase-aligned baseband signal is output;

[0025] According to the phase-aligned baseband signal and the mode control signal, time domain filtering is performed, and a zero-crossing detection feature point is extracted, a phase difference between adjacent symbols is calculated, and a phase difference sequence is output.

[0026] According to the communication antenna steering control system provided by the application, the time synchronization module comprises:

[0027] A timestamp alignment unit is configured to align the phase difference sequence and attitude data in hardware state information to a unified time reference through a PTP protocol;

[0028] A resampling filter unit is configured to resample the phase difference sequence through a cubic spline interpolation algorithm, and match the unified time reference, and output a resampled phase difference.

[0029] According to the communication antenna steering control system provided by the application, the angle calculation module comprises:

[0030] A quaternion solution unit is configured to convert the resampled phase difference and baseline parameters into a geodetic coordinate system azimuth based on a rotation matrix inverse solution method;

[0031] A baseline mapping unit is configured to compensate for baseline installation deviation according to an antenna deviation matrix, and output a geometrically corrected azimuth;

[0032] A dynamic compensation unit is configured to fuse IMU angular velocity data according to the geometrically corrected azimuth, eliminate mechanical hysteresis effects through an extended Kalman filter, and output an estimated azimuth.

[0033] According to the communication antenna steering control system provided by the application, the step of outputting the estimated azimuth comprises:

[0034] According to the geometric correction azimuth angle, an extended Kalman filter state model is established to output a predicted state vector; the extended Kalman filter state model comprises a state equation and an observation equation; the state equation is expressed as:

[0035]

[0036] In the formula, k is a time step, x k The extended Kalman filter state equation is v g is a Gaussian noise, w g,k is an IMU angular velocity measurement, θ, is a geodetic coordinate system azimuth angle and a pitch angle; the observation equation is expressed as:

[0037]

[0038] In the formula, z k is an observation equation, θ me,k is a measured azimuth angle, Φ me,k is a measured pitch angle, β roll , β pitch are baseline installation deviations of the azimuth angle and the pitch angle, respectively, η θ and η Φ are measurement noises of the azimuth angle and the pitch angle, respectively;

[0039] According to the predicted state vector and the dead time, a reverse compensation amount is calculated by a mechanical hysteresis compensation algorithm, and is expressed as:

[0040]

[0041] In the formula, is a reverse compensation amount, θ est,k-1 represents an estimated value of a true angle of a control system in a k-1 sampling period, K is a rudder gain, T is a time constant, τ d is a dead time, s is a Laplace variable, T s is a sampling period, represents an exponential delay term of a mechanical hysteresis model, is an angular velocity estimation, represents a displacement during a reverse compensation delay period, u k is a control signal input, represents an influence of a current control signal, represents a dynamic response of a rudder.

[0042] According to the communication antenna turning control system provided by the application, the turning control module comprises:

[0043] A deviation calculation unit is configured to calculate a vector deviation between an estimated azimuth angle and a target pointing angle, and to perform a spherical coordinate system conversion to output a three-dimensional cosine deviation vector.

[0044] The sliding mode control unit designs a nonlinear sliding mode surface according to the three-dimensional cosine deviation vector and a motor torque characteristic curve, and generates a torque instruction in combination with an anti-saturation PID algorithm.

[0045] According to the communication antenna steering control system provided by the application, the step of spherical coordinate system conversion comprises:

[0046] The estimated azimuth angle and the target pointing angle are converted into radian units and normalized in a preset angle range, and a structured spherical coordinate is output.

[0047] According to the structured spherical coordinate, the coordinate components of the estimated azimuth angle and the target pointing angle are calculated respectively, and the coordinate components are normalized, and a unit direction vector is output.

[0048] According to the unit direction vector, a vector deviation is calculated, and a three-dimensional cosine deviation vector is output.

[0049] According to the communication antenna steering control system provided by the application, the steering engine driving module comprises:

[0050] The torque conversion unit is used for converting the torque instruction into a PWM duty cycle, pre-compensating the PWM waveform parameters by using a dead zone compensation algorithm, and outputting the pre-compensated PWM waveform parameters.

[0051] The PWM production unit is used for generating two complementary PWM signals through HRTimer according to the pre-compensated PWM waveform parameters, and outputting the PWM waveform for driving the motor.

[0052] According to the communication antenna steering control method provided by the application, the initial state of the communication antenna is collected, and the hardware state information is collected in real time through the SPI bus.

[0053] According to the initial state, the initial frequency of the digital control oscillator is configured, the parallel correlator group is started to scan the carrier frequency, and the frequency domain power spectrum data is calculated; when the frequency domain power spectrum data exceeds the preset dynamic threshold, the tracking mode is switched, and the phase difference sequence is output through the FIR filter;

[0054] The phase difference sequence and the synchronization trigger signal are associated by using a timestamp associator to map the phase data and the attitude data in the hardware state information to a unified time reference, and a resampled phase difference is output.

[0055] The resampled phase difference and the baseline parameters are mapped into the azimuth angle based on the quaternion solution, and the IMU angular velocity data is superimposed for dynamic compensation, and an estimated azimuth angle is output.

[0056] The deviation between the estimated azimuth angle and the target pointing angle is calculated, and a torque instruction is generated through a sliding mode controller.

[0057] According to the torque instruction, a PWM waveform is generated by the HRTimer to drive the motor.

[0058] The application provides a communication antenna steering control system and method, which realizes high-sensitivity capture of signals in a wide frequency band by adopting a multi-stage phase-locked loop architecture and a dynamic threshold adaptive algorithm, by means of cascaded frequency division coefficient compensation and a FIR comb filter. The phase lag of a steering engine system is greatly reduced by fusing an extended Kalman filter and a mechanical hysteresis compensation algorithm, by means of a discretized hysteresis model and a pre-compensation term design. The system can still maintain high pointing accuracy in a dynamic scene by combining real-time fusion of IMU angular velocity. The sliding mode control unit adopts a smooth sign function to replace the traditional step control, so that the chattering amplitude is greatly reduced while the fast convergence characteristic is maintained. The anti-saturation PID algorithm uses a double-gain switching mechanism to ensure the steady-state accuracy while greatly improving the response speed of the system to large angle deviations, thereby breaking through the performance bottleneck of the traditional control algorithm in nonlinear working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0060] Figure 1 It is a structural schematic diagram of a communication antenna steering control system provided by an embodiment of the application.

[0061] Figure 2 It is a step diagram of a communication antenna steering control method provided by an embodiment of the application. DETAILED DESCRIPTION

[0062] In order to make the objects, technical solutions and advantages of the application clearer, the technical solutions in the application will be described clearly and completely in combination with the drawings in the application. Obviously, the described embodiments are some embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0063] Embodiment one:

[0064] The following will be described in combination with Figures 1-2 a communication antenna steering control system and method of the application.

[0065] As Figure 1As shown, the communication antenna steering control system provided by the embodiment of the application comprises a parameter configuration module, a signal acquisition and tracking module, a time synchronization module, an angle calculation module, a steering control module and a steering engine driving module.

[0066] The parameter configuration module is configured to acquire an initial state of the communication antenna, output a calibration parameter package, and collect hardware state information in real time through an SPI bus.

[0067] The signal acquisition and tracking module is configured to configure an initial frequency of a digital controlled oscillator according to the calibration parameter package, start a parallel correlator group to scan a carrier frequency, and calculate frequency domain power spectrum data. When the frequency domain power spectrum data exceeds a preset dynamic threshold, the signal acquisition and tracking module is switched to a tracking mode, and a phase difference sequence is output through a FIR filter. The FIR filter is a finite impulse response comb filter, has a linear phase characteristic, and can realize a specific frequency suppression function by adjusting a comb tooth spacing. The signal acquisition and tracking module comprises a parameter initialization unit, a parallel correlator unit, a detection switching unit and a tracking processing unit. The parameter initialization unit is configured to set a frequency division coefficient of the digital controlled oscillator according to the calibration parameter package, initialize a correlator group register, and output a correlator group initialization completion signal. The frequency division coefficient is calculated through a phase-locked loop frequency multiplication formula, and is expressed as:

[0068]

[0069] In the formula, N is a feedback frequency division coefficient, f t is a signal frequency finally output by the phase-locked loop, f r is a reference frequency input from outside, and is provided by a crystal oscillator. If the signal frequency finally output by the phase-locked loop is much higher than the reference frequency input from outside, multi-stage frequency multiplication needs to be performed, and is expressed as:

[0070]

[0071] In the formula, N i is a feedback frequency division coefficient of the i-th PLL, and determines frequency multiplication capability of the i-th stage. R i is a reference frequency division coefficient of the i-th PLL, and is used to reduce an influence of reference clock noise on the system. On the other hand, a frequency division coefficient dynamic compensation algorithm can be used to correct a frequency division value in real time according to VCO voltage control sensitivity (±50ppm). The correlator group register initialization comprises: 16-group FIR filter coefficient loading, and 4-mixing path gain balance setting.

[0072] The parallel correlator unit is used to calculate the frequency domain power spectrum data by four-channel DDC according to the initialization completion signal and hardware state information. The four-channel DDC (Direct Digital Control) controller realizes the monitoring and control of the equipment through four main channels. The analog input channel is responsible for collecting analog signals from sensors such as temperature, humidity, pressure, flow, and other environmental parameters and equipment states. These signals are converted into standard electrical signals by transducers and further converted into digital signals for computer processing. The digital input channel is used to receive digital signals from switching devices such as buttons, limit switches, etc. These signals are directly recognized and processed by the computer in digital form. The analog output channel is used to convert the digital signals processed by the computer into analog signals to control analog devices such as regulating valves, frequency converters, etc. The digital output channel is used to directly output digital signals to control digital devices such as relays, indicator lights, etc. The DDC contains a three-level structure of digital control oscillator, mixer, and decimation filter, which can realize the down-conversion processing of the band-pass signal. Through efficient frequency band scanning and power spectrum calculation, the carrier frequency of the target signal can be quickly located, and the response speed of the system can be improved.

[0073] The detection switching unit is used to trigger mode switching by comparing the frequency domain power spectrum data with the preset threshold, and output the mode control signal. The dynamic threshold uses an adaptive algorithm, and its reference value is the average power spectrum density plus 3 times the standard deviation. The threshold value can be automatically adjusted according to the change of the signal environment, avoiding false positives or false negatives caused by fixed thresholds, and improving the robustness of the system.

[0074] The tracking processing unit is used to run the frequency-locked loop and phase-locked loop joint algorithm by combining the mode control signal and the frequency domain power spectrum data, and output the phase difference sequence through the FIR comb filter. The specific steps include:

[0075] Analyzing the mode control signal to confirm that it is currently in tracking mode. Extract the carrier frequency offset and real-time noise power in the frequency domain power spectrum data, and output the tracking mode parameter package. A 16-bit state machine architecture is used to analyze the control word containing three priority fields. The control word usually contains multiple priority fields (such as stability priority, tracking rate priority, etc.), and the CRC (Cyclic Redundancy Check) check is used to ensure the integrity of the command.

[0076] According to the tracking mode parameter package and the calibration parameter package, the frequency error is calculated. And according to the frequency error, the second-order frequency-locked loop algorithm is run to output the frequency control word, which is used to adjust the frequency of the local digital oscillator.

[0077] According to the frequency control word, the frequency of the digital controlled oscillator is adjusted, so that the signal enters the PLL lock bandwidth, and a frequency-locked baseband signal is output.

[0078] According to the frequency-locked baseband signal, a phase error is calculated, and a third-order phase-locked loop algorithm is run, and a phase control word is output.

[0079] According to the phase control word, a quadrature local carrier signal is generated, and mixed with the input signal, and a phase-aligned baseband signal is output.

[0080] According to the phase-aligned baseband signal and the mode control signal, time domain filtering is performed, and a zero-crossing detection feature point is extracted, a phase difference between adjacent symbols is calculated, and a phase difference sequence is output.

[0081] Further, the time synchronization module is used to associate the phase difference sequence with the synchronization trigger signal using a timestamp associator to map the phase data and the attitude data in the hardware state information to a unified time reference, and output a resampled phase difference. The time synchronization module includes a timestamp alignment unit and a resampling filtering unit. The timestamp alignment unit is used to align the phase difference sequence and the attitude data in the hardware state information to a unified time reference through a PTP protocol. The resampling filtering unit is used to resample the phase difference sequence through a cubic spline interpolation algorithm and match the unified time reference, and output a resampled phase difference.

[0082] The angle calculation module is used to map the resampled phase difference and the baseline parameters into an azimuth angle based on a quaternion solution, and superimpose IMU angular velocity data for dynamic compensation, and output an estimated azimuth angle. The angle calculation module includes a quaternion solution unit, a baseline mapping unit and a dynamic compensation unit.

[0083] The quaternion solution unit is used to convert the resampled phase difference and the baseline parameters into geodetic coordinate system azimuth angle based on a rotation matrix inverse solution, i.e. conversion from quaternion to rotation matrix, and the specific way includes: the phase difference obtained from the multi-antenna array is filtered and resampled to obtain stable signal features. The quaternion is used to represent spatial rotation, which avoids singular problems such as gimbal lock, and the attitude information of the antenna array relative to the geodetic coordinate system is serialized by solving. The quaternion is converted into a rotation matrix, which is applied to the coordinate transformation of the differential signal to obtain the original azimuth angle estimate.

[0084] The baseline mapping unit is used to compensate for the baseline installation deviation according to the antenna deviation matrix, correct the azimuth angle calculated by the quaternion, and output a geometrically corrected azimuth angle after matrix transformation, which can improve the overall measurement accuracy.

[0085] The dynamic compensation unit is used to fuse the IMU angular velocity data according to the geometric correction azimuth angle, collect the angular velocity data provided by the IMU, and capture the rapid attitude change. The mechanical hysteresis effect is eliminated by the extended Kalman filter, and the estimated azimuth angle is output. The mechanical hysteresis effect is eliminated in order to reduce the measurement deviation in the dynamic environment and improve the real-time and stability of the azimuth angle. The specific steps of the estimated azimuth angle output include:

[0086] According to the geometric correction azimuth angle, an extended Kalman filter state model is established, and a predicted state vector is output. The extended Kalman filter state model includes a state equation and an observation equation. The state equation is represented as:

[0087]

[0088] In the formula, k is the time step, x k The extended Kalman filter state equation is v g is a Gaussian noise, w g,k is an IMU angular velocity measurement value, θ, is the azimuth angle and the pitch angle in the geodetic coordinate system. The observation equation is represented as:

[0089]

[0090] In the formula, z k is the observation equation, θ me,k is the measured azimuth angle, Φ me,k is the measured pitch angle, β roll , β pitch are the baseline installation deviations of the azimuth angle and the pitch angle, η θ and η Φ are the measurement noises of the azimuth angle and the pitch angle.

[0091] According to the predicted state vector and the dead time, the reverse compensation amount is calculated by a mechanical hysteresis compensation algorithm, which is represented as:

[0092]

[0093] In the formula, is the reverse compensation amount, θ est,k-1 represents the estimated value of the true angle by the control system in the k-1 sampling period, K is the gain of the rudder, T is the time constant, τ d is the dead time, s is the Laplace variable, T s is the sampling period, represents the exponential delay term of the mechanical hysteresis model, is the angular velocity estimation, represents the displacement during the reverse compensation delay, u k is the control signal input, represents the influence of the current control signal, represents the dynamic response of the steering engine.

[0094] The detailed calculation is as follows:

[0095] First, the original lag model transfer function is represented as:

[0096]

[0097] After discretization of the lag model, it is represented as:

[0098]

[0099] In the formula, θ del,k represents the actual angle value at the kth sampling period, is the response of the first-order inertia link, represents the influence of the current control signal, is a delay term, representing the delay of signal transmission and mechanical action.

[0100] Finally, the delay error is corrected by the feedforward term, represented as:

[0101]

[0102] In the formula, is the preposition, which represents that the steering engine maintains the current angular velocity d for a delay τ , predicts the displacement and compensates in the opposite direction.

[0103] Further, the steering control module is used to calculate the deviation between the estimated azimuth angle and the target pointing angle, and generate a torque instruction through a sliding mode controller. The steering control module includes a deviation calculation unit and a sliding mode control unit. The deviation calculation unit is used to calculate the vector deviation between the estimated azimuth angle and the target pointing angle, and perform spherical coordinate system conversion, outputting a three-dimensional cosine deviation vector. The steps of spherical coordinate system conversion include:

[0104] Convert the estimated azimuth angle and the target pointing angle into radian units and normalize them to a preset angle range, outputting structured spherical coordinates. The preset angle range of the estimated azimuth angle is usually [-π, π], and the preset angle range of the target pointing angle is usually [-π / 2, π / 2], which is used to limit the range of the pitch angle.

[0105] According to the structured spherical coordinates, the coordinate components of the estimated azimuth angle and the target pointing angle are calculated respectively, and the coordinate components are normalized, outputting a unit direction vector. The calculation of the coordinate components of the estimated azimuth angle is represented as:

[0106]

[0107]

[0108]

[0109] where x set , y set , z set are coordinate components of the estimated azimuth angle, θ est , Φ est are the estimated azimuth angle and the elevation angle.

[0110] The calculation of the coordinate components of the target pointing angle is represented as:

[0111]

[0112]

[0113]

[0114] where x tar , y tar , z tar are coordinate components of the target pointing angle, θ tar , Φ tar are the target azimuth angle and the elevation angle.

[0115] According to the unit direction vector, the vector deviation calculation is performed, and a three-dimensional cosine deviation vector is output. The calculation method of the vector deviation is represented as:

[0116]

[0117]

[0118]

[0119] where Δx, Δy, Δz are the vector deviation values of the two direction vectors of the estimated azimuth angle and the target pointing angle. The three direction vector differences are combined to obtain a three-dimensional cosine deviation vector ΔV = [Δx, Δy, Δz].

[0120] The sliding mode control unit is used to design a nonlinear sliding mode surface according to the three-dimensional cosine deviation vector and the motor torque characteristic curve, which is represented as:

[0121]

[0122] where S i is the sliding mode surface function value, that is, the output value of the nonlinear control law. represents the error dynamic variable, that is, the first derivative of the system error, which is used to represent the rate of change of the azimuth angle deviation. tanh(ΔV i) represents a smooth sign function, reducing chattering. γ i is an integral coefficient, c i is a proportional coefficient, used to directly proportionally amplify the error term, determining the sensitivity of the system to the steady-state error, increasing c i can accelerate the response speed.

[0123] Finally, the torque command is generated by combining the anti-windup PID algorithm, which is represented as:

[0124]

[0125] In the formula, P represents the torque command, f(S i ) is a switching function, K1 is a linear gain, that is, the control gain in the low amplitude region, used to provide basic control force for fast response and suppress steady-state error in the small error range. K2 is a nonlinear gain, that is, the control gain in the high amplitude region, used to enhance the suppression ability of large errors, and the smooth saturation is realized through the tanh function. β is a smoothing coefficient, which is a parameter for controlling the convergence speed of the tanh function. The larger β is, the faster the tanh(β·S i ) approaches the sign function, and when β→∞, tanh(β·S i )≈sign(S i ). S th is a switching threshold, that is, the threshold value of the amplitude of the sliding mode surface.

[0126] Finally, the servo drive module is used to generate a PWM waveform to drive the motor according to the torque command through the HRTimer. The PWM waveform is a square wave, and its characteristic is that the duration of the high level and the low level can be changed, thereby changing the duty cycle of the waveform. The servo drive module includes a torque conversion unit and a PWM production unit.

[0127] The torque conversion unit is used to convert the torque command into a PWM duty cycle, and a dead zone compensation algorithm is used to pre-compensate the PWM waveform parameters, and the pre-compensated PWM waveform parameters are output.

[0128] The PWM production unit is used to generate two complementary PWM signals through the HRTimer according to the pre-compensated PWM waveform parameters, and output the PWM waveform to drive the motor.

[0129] Based on the same overall inventive concept, the present application also protects a communication antenna steering control method. The communication antenna steering control method provided by the present application is described below, and the communication antenna steering control method described below can be mutually corresponding and referred to the communication antenna steering control system described above.

[0130] Figure 2 is a step diagram of the communication antenna steering control method provided by the embodiment of the present application.

[0131] As Figure 2 shown, the communication antenna steering control method provided by the embodiment of the application comprises:

[0132] Collecting the initial state of the communication antenna, and collecting the hardware state information in real time through the SPI bus.

[0133] According to the initial state, configuring the initial frequency of the digital controlled oscillator, starting the parallel correlator group to scan the carrier frequency, and calculating the frequency domain power spectrum data. When the frequency domain power spectrum data exceeds the preset dynamic threshold, switching to the tracking mode, and outputting the phase difference sequence through the FIR filter.

[0134] Associating the phase difference sequence with the synchronous trigger signal using the time stamp correlator to map the phase data and the attitude data in the hardware state information to a unified time reference, and outputting the resampled phase difference.

[0135] Mapping the resampled phase difference and the baseline parameter into the azimuth angle based on the quaternion solution, and superimposing the IMU angular velocity data for dynamic compensation, and outputting the estimated azimuth angle.

[0136] Calculating the deviation between the estimated azimuth angle and the target pointing angle, and generating the torque instruction through the sliding mode controller.

[0137] According to the torque instruction, generating the PWM waveform to drive the motor through the HRTimer.

[0138] In summary, the communication antenna steering control system and method provided by the application realize high-sensitivity capture of signals in a wide frequency band by adopting a multi-stage phase-locked loop architecture and a dynamic threshold adaptive algorithm, through cascading frequency division coefficient compensation and a FIR comb filter. The phase lag of the steering engine system is greatly reduced by discretizing the lag model and designing a pre-compensation term. The real-time fusion of the IMU angular velocity enables the system to maintain high pointing accuracy in dynamic scenarios. The sliding mode control unit uses a smooth sign function to replace the traditional step control, which greatly reduces the chattering amplitude while maintaining fast convergence characteristics. Through the anti-saturation PID algorithm using a double-gain switching mechanism, the system's response speed to large angle deviations is greatly improved while ensuring steady-state accuracy, breaking through the performance bottleneck of traditional control algorithms in nonlinear working conditions.

[0139] Those skilled in the art can clearly understand the technical solutions of the various embodiments from the above description of the embodiments, and the various embodiments can be implemented by means of software with the necessary general hardware platforms, and of course, can also be implemented by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part of the prior art that makes a contribution, can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0140] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A communication antenna steering control system, characterized by, The method comprises the following steps: a parameter configuration module is configured to obtain an initial state of a communication antenna and output a calibration parameter package; real-time hardware state information is collected through an SPI bus; a signal capture and tracking module is configured to configure an initial frequency of a digital controlled oscillator according to the calibration parameter package, start a parallel correlator group to scan a carrier frequency, and calculate frequency domain power spectrum data; when the frequency domain power spectrum data exceeds a preset dynamic threshold, a tracking mode is switched, a phase difference sequence is output through a FIR filter, and the phase difference sequence is mapped to a unified time reference with attitude data in the hardware state information using a time stamp coupler, and a resampled phase difference is output; a time synchronization module is configured to map the phase difference sequence and the attitude data in the hardware state information to the unified time reference using the time stamp coupler, and output the resampled phase difference; an angle calculation module is configured to map the resampled phase difference and baseline parameters to an azimuth angle based on a quaternion solution, superimpose IMU angular velocity data for dynamic compensation, and output an estimated azimuth angle; the angle calculation module comprises: a quaternion solution unit is configured to convert the resampled phase difference and the baseline parameters into an azimuth angle in a geodetic coordinate system based on a rotation matrix inverse solution; a baseline mapping unit is configured to compensate for baseline installation deviation according to an antenna deviation matrix, and output a geometrically corrected azimuth angle; a dynamic compensation unit is configured to fuse the IMU angular velocity data according to the geometrically corrected azimuth angle, eliminate mechanical hysteresis effects through extended Kalman filtering, and output the estimated azimuth angle; the step of outputting the estimated azimuth angle comprises: an extended Kalman filtering state model is established according to the geometrically corrected azimuth angle, and a predicted state vector is output; the extended Kalman filtering state model comprises a state equation and an observation equation; the state equation is represented as: ； where k is a time step, x k The extended Kalman filter state equation is v g is a Gaussian noise, w g,k is an IMU angular velocity measurement, θ, is the azimuth and pitch angle of the geodetic coordinate system; the observation equation is represented as: ； where z k is the observation equation, θ me,k is the measured azimuth angle, Φ me,k is the measured elevation angle, β roll , β pitch are the baseline installation biases of the azimuth and elevation angles, respectively, η θ and η Φ are the measurement noises of the azimuth and elevation angles, respectively. a reverse compensation amount is calculated through a mechanical hysteresis compensation algorithm according to the predicted state vector and a dead time, and is represented as: ； wherein, is the reverse compensation amount, θ est,k-1 denotes the estimation value of the true angle by the control system in the k-1th sampling period, K is the gain of the steering engine, T is the time constant, τ d is the dead time, s is the Laplace variable, T s is the sampling period, denotes the exponential delay term of the mechanical lag model, is the angular velocity estimation, denotes the displacement during the reverse compensation delay, u k is the control signal input, denotes the influence of the current control signal, denotes the dynamic response of the steering engine; a steering control module is configured to calculate a deviation between the estimated azimuth angle and a target pointing angle, and generate a torque instruction through a sliding mode controller; a steering engine driving module is configured to generate a PWM waveform to drive a motor through an HRTimer according to the torque instruction.

2. A communications antenna steering control system according to claim 1, wherein, The signal capture and tracking module comprises: a parameter initialization unit is configured to set a digital controlled oscillator frequency division coefficient according to the calibration parameter package, initialize a correlator group register, and output a correlator group initialization completion signal; a parallel correlator unit is configured to perform carrier frequency band scanning through a four-channel DDC according to the initialization completion signal and the hardware state information, and calculate the frequency domain power spectrum data; a detection switching unit is configured to trigger mode switching by comparing the frequency domain power spectrum data with a preset threshold, and output a mode control signal; a tracking processing unit is configured to run a frequency locked loop-phase locked loop joint algorithm in combination with the mode control signal and the frequency domain power spectrum data, and output the phase difference sequence through a FIR comb filter.

3. A communications antenna steering control system according to claim 2, wherein, The step of outputting the phase difference sequence comprises: the mode control signal is analyzed, it is confirmed that the current is in a tracking mode; a carrier frequency offset and real-time noise power in the frequency domain power spectrum data are extracted, and a tracking mode parameter package is output. According to the tracking mode parameter package and the calibration parameter package, a frequency error is calculated; and a second-order frequency-locked loop algorithm is run according to the frequency error, and a frequency control word is output; According to the frequency control word, the frequency of the numerically controlled oscillator is adjusted, so that the signal enters the PLL locking bandwidth, and a frequency-locked baseband signal is output; According to the frequency-locked baseband signal, a phase error is calculated, and a third-order phase-locked loop algorithm is run, and a phase control word is output; According to the phase control word, a quadrature local carrier signal is generated, and is mixed with the input signal, and a phase-aligned baseband signal is output; According to the phase-aligned baseband signal and the mode control signal, time domain filtering is performed, and a zero-crossing detection feature point is extracted, a phase difference between adjacent symbols is calculated, and a phase difference sequence is output.

4. A communications antenna steering control system according to claim 2, wherein, The time synchronization module comprises: a timestamp alignment unit configured to align the phase difference sequence and the attitude data in the hardware state information to the unified time reference through a PTP protocol; a resampling filter unit configured to resample the phase difference sequence through a cubic spline interpolation algorithm and match the unified time reference, and output the resampled phase difference.

5. A communications antenna steering control system according to claim 1 wherein, The steering control module comprises: a deviation calculation unit configured to calculate a vector deviation between the estimated azimuth angle and the target pointing angle, and perform spherical coordinate system conversion, and output a three-dimensional cosine deviation vector; a sliding mode control unit configured to design a nonlinear sliding mode surface according to the three-dimensional cosine deviation vector and a motor torque characteristic curve, and generate the torque instruction in combination with an anti-windup PID algorithm.

6. A communications antenna steering control system according to claim 5, wherein, The step of performing spherical coordinate system conversion comprises: converting the estimated azimuth angle and the target pointing angle into radian units and normalizing them into a preset angle range, and outputting structured spherical coordinates; calculating coordinate components of the estimated azimuth angle and the target pointing angle respectively according to the structured spherical coordinates, and performing normalization processing on the coordinate components, and outputting a unit direction vector; performing vector deviation calculation according to the unit direction vector, and outputting the three-dimensional cosine deviation vector.

7. A communications antenna steering control system according to claim 1 wherein, The steering engine driving module comprises: a torque conversion unit configured to convert the torque instruction into a PWM duty cycle, and pre-compensate PWM waveform parameters using a dead zone compensation algorithm, and output pre-compensated PWM waveform parameters; a PWM production unit configured to generate two complementary PWM signals through an HRTimer according to the pre-compensated PWM waveform parameters, and output the PWM waveform for driving the motor.

8. A method of steering a communication antenna, such as the communication antenna steering system of any one of claims 1 to 7, characterized by, It comprises: collecting an initial state of a communication antenna, and collecting hardware state information in real time through an SPI bus; configuring an initial frequency of a numerically controlled oscillator according to the initial state, starting a parallel correlator group to scan a carrier frequency, and calculating frequency domain power spectrum data; when the frequency domain power spectrum data exceeds a preset dynamic threshold, switching to a tracking mode, and outputting a phase difference sequence through a FIR filter; associating the phase difference sequence with a synchronization trigger signal using a timestamp associator to map phase data to a unified time reference with attitude data in the hardware state information, and output a resampled phase difference; The resampling phase difference and baseline parameters are mapped to azimuth angle based on quaternion solution, and IMU angular velocity data is superimposed for dynamic compensation, and an estimated azimuth angle is output; A deviation between the estimated azimuth angle and a target pointing angle is calculated, and a torque instruction is generated by a sliding mode controller; According to the torque instruction, a PWM waveform is generated by an HRTimer to drive the motor.

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