Anti-resistance and vibration suppression method for satellite-borne coarse pointing mechanism

Abstract

The invention relates to a satellite-borne coarse pointing mechanism anti-vibration and vibration suppression method, which comprises the following steps: dynamically adjusting a proportional parameter KP, an integral parameter KI and a differential parameter KD through a PID self-adaptive control algorithm to realize vibration prevention in a CPA operation process; dynamic matching and connection of dead time are achieved through the dead time dynamic adjusting module, dynamic compensation of motor current harmonics is achieved through the full-band harmonic compensation module, and vibration resistance in the CPA operation process is achieved. A strong detection mode is added in a full-band harmonic compensation module, vibration amplitude detection and vibration grade division are carried out, a strategy of combining grading response and parameter dynamic feedback adjustment is adopted for different vibration grades, and vibration suppression in the CPA operation process is achieved. The method aims at solving the problem of vibration of the CPA caused by starting transient oscillation, PWM dead time mismatching, motor current harmonic waves and external disturbance in satellite-borne laser communication, and has obvious advantages.

Description

Technical Field

[0001] This invention relates to the technical field of control of spaceborne coarse pointing assembly (CPA) in inter-satellite laser communication, and specifically to a method for vibration prevention and suppression of spaceborne coarse pointing assembly (CPA). Background Technology

[0002] In spaceborne laser communication, the coarse pointing mechanism (CPA) is a core component of the acquisition, tracking, and pointing (ATP) system. Its core function is to achieve wide-range and rapid alignment of the laser beam. It is the key to establishing and maintaining the link of the entire laser communication system and is crucial to the reliability and stability of inter-satellite laser communication.

[0003] However, in practical use, several factors can cause CPA vibration, leading to difficulties in link establishment or even the inability to maintain link stability or loss of lock. These can be summarized into three typical scenarios: First, during CPA startup, insufficient matching between the control strategy and the dynamic characteristics of the CPA, such as rotational inertia, can easily trigger transient oscillations in the closed-loop system, causing the CPA pointing angle to fluctuate periodically around the target value. Second, onboard CPAs are often driven by FPGA-generated Space Vector Pulse Width Modulation (SVPWM) signals to control the inverter. The switching characteristics of the PWM wave, insufficient or mismatched dead time, poor dead time calculation model integration, changes in rotational speed leading to changes in commutation frequency, and motor current harmonics can all superimpose and propagate through layers, causing CPA vibration. Third, during satellite operation, external factors such as instantaneous torque disturbances from satellite attitude adjustments, solar panel drives, and momentum wheel disturbances can also cause vibration in a stable CPA.

[0004] Therefore, it is essential to propose a spaceborne coarse pointing mechanism that overcomes the aforementioned technical problems.

[0005] It is understood that the above statements only provide background information related to the present invention and do not necessarily constitute prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a vibration prevention and suppression method for a spaceborne coarse pointing mechanism, which aims to solve the vibration problems caused by transient oscillations during startup, PWM dead time mismatch, motor current harmonics, and external disturbances in spaceborne laser communication CPA.

[0007] To achieve the above objectives, this invention provides a vibration prevention and suppression method for a spaceborne coarse pointing mechanism (CPA), comprising: dynamically adjusting the proportional parameter KP, integral parameter KI, and derivative parameter KD through a PID adaptive control algorithm to achieve vibration prevention during CPA operation; dynamically matching and connecting the dead time through a dead time dynamic adjustment module, and dynamically compensating for motor current harmonics through a full-band harmonic compensation module to achieve vibration resistance during CPA operation; and adding a strong-mode detection mode to the full-band harmonic compensation module to detect vibration amplitude, classify vibration levels, and adopt a strategy combining graded response and dynamic parameter feedback adjustment for different vibration levels to achieve vibration suppression during CPA operation.

[0008] Preferably, the PID adaptive control algorithm includes: dividing the control region into IV based on the error e and the error change rate ec; for region I, e>0 and ec<0 and |ec|> preset change rate threshold, setting the rule: increase KP, set KI=0, and increase KD; for region II, e<0 and ec<0, setting the rule: decrease KP, set KI=0, and increase KD; for region III, e<0 and ec>0, setting the rule: decrease KP and KD, and set KI=0; for region IV, e>0 and ec>0, setting the rule: increase KP and KI, and decrease KD; for region V, e>0 and ec<0 and |ec|≤ preset change rate threshold, setting the rule: decrease KP, increase KI, and maintain KD.

[0009] Preferably, the dead time dynamic adjustment module divides the mechanical angular velocity into an extremely low speed segment, an ultra-low speed segment, and a normal low speed segment, and generates a corresponding dead time according to different speed segments.

[0010] Preferably, the dead time calculation formula for the extremely low speed range is: The formula for calculating the dead time in the ultra-low speed range is: The dead time calculation formula for the normal low-speed range is: in, Dead time; This is the proportionality coefficient; It is the mechanical rotation angle; It is a constant; This is the minimum dead time for the power transistor's safety switch; This is the dead zone correction factor for the extremely low speed range; This refers to the critical characteristic speed between the extremely low speed range and the ultra-low speed range. This is the linear adjustment coefficient for the dead time in the normal low-speed range; This is the minimum dead time in the normal low-speed range.

[0011] Preferably, the extremely low speed range corresponds to 0.001-0.01° / s; the ultra-low speed range corresponds to 0.01-1° / s; and the normal low speed range corresponds to 1-5° / s.

[0012] Preferably, the full-band harmonic compensation module includes: a multi-resolution decomposition unit for extracting harmonic components of different frequency bands from the motor; and a segmented compensation command generation unit for generating targeted compensation current commands based on the harmonic order and speed segment characteristics, and for injecting reverse harmonics to cancel the electromagnetic force fluctuations of the original harmonics, control the vibration amplitude, and achieve accurate harmonic cancellation.

[0013] Preferably, the full-band harmonic compensation module is equipped with an enhanced detection mode; the enhanced detection mode includes multi-dimensional vibration feature extraction and vibration level classification; wherein, the multi-dimensional vibration feature extraction is used to detect the CPA vibration amplitude; and the vibration level is classified according to the ratio of the vibration amplitude to a preset vibration amplitude threshold.

[0014] Preferably, the vibration levels include: mild vibration, which is a single harmonic component with a magnitude of 1-1.5 times the preset vibration amplitude threshold; moderate vibration, which is the superposition of multiple harmonic components with a magnitude of 1.5-2 times the preset vibration amplitude threshold; and severe vibration, which is the coupling of harmonics and mechanical resonance with a magnitude greater than 2 times the preset vibration amplitude threshold.

[0015] Preferably, the enhanced detection mode can detect the vibration decay rate for dynamic parameter feedback adjustment; wherein, if the vibration decay rate is less than a preset vibration decay rate threshold, the compensation coefficient is increased; if the compensation is excessive, the compensation coefficient is decreased, and the time constant is extended or the fast Fourier transform window length is shortened.

[0016] Preferably, if the vibration amplitude is lower than the preset vibration amplitude threshold for three consecutive control cycles, the enhanced detection mode is exited and the compensation parameters are restored to normal values.

[0017] In summary, compared with existing technologies, the vibration suppression and anti-vibration method for a spaceborne coarse pointing mechanism provided by this invention is software-based. Targeting the specific usage scenarios of spaceborne CPAs, it employs an experience-based PID adaptive control algorithm to prevent transient oscillations during the CPA startup phase, thereby achieving vibration prevention. It utilizes a dead-time dynamic adjustment module and a full-band harmonic compensation module to achieve dynamic matching and connection of dead time and dynamic compensation of motor current harmonics, thus achieving vibration resistance during CPA operation. Furthermore, by adding a strong-mode detection mode to the full-band harmonic compensation module to detect vibration amplitude, classify vibration levels, and employ a strategy combining graded response and dynamic parameter feedback adjustment for different vibration levels, it achieves vibration suppression during CPA operation, demonstrating significant advantages. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the vibration suppression and anti-vibration method of the spaceborne coarse pointing mechanism in this invention; Figure 2 This is a schematic diagram of the CPA control standard curve in this invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and by providing a detailed description of a preferred embodiment.

[0020] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in the present invention, provided that they do not affect the effects and objectives that the present invention can produce.

[0021] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the expressly listed elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0022] like Figure 1 As shown, the present invention provides a method for vibration damping and resistance of a spaceborne coarse pointing mechanism, comprising: Based on engineering experience with CPA servo control systems, the initial parameters of the PID adaptive control algorithm are determined to achieve vibration prevention during CPA operation. The dead time is dynamically matched and connected by a dead time dynamic adjustment module, and the motor current harmonics are dynamically compensated by a full-band harmonic compensation module, thus achieving vibration resistance during CPA operation. By adding a strong-mode detection mode to the full-band harmonic compensation module, vibration amplitude is detected, vibration levels are classified, and a strategy combining graded response and dynamic parameter feedback adjustment is adopted for different vibration levels to achieve vibration suppression during CPA operation.

[0023] Furthermore, it is understandable that adopting traditional PID control strategies in CPA servo control systems presents certain engineering limitations. For example, firstly, fixed PID parameters designed for specific operating conditions degrade in performance when operating conditions change (such as load or speed range); and secondly, insufficient robustness to external disturbances leads to limited anti-disturbance capabilities. Secondly, PID control strategies have their own inherent limitations, such as increasing response speed (increasing Kp / Ki) easily leading to overshoot and oscillation, and enhancing stability (decreasing Kp / Ki) slowing down the response. Therefore, CPA servo control systems for spaceborne laser communication require more advanced control strategies.

[0024] Therefore, this invention addresses vibration prevention during CPA operation by first formulating several typical rules based on engineering experience of CPA servo control systems, and then using an experience-based custom PID parameter control strategy to improve the stability of the servo control system and reduce or even eliminate vibration phenomena in the control curve.

[0025] That is, based on the CPA operating status (such as error e, error change rate ec), the control characteristics of the current CPA servo control system are determined, and the PID control parameters are dynamically adjusted; among them, the PID control parameters include: KP (proportional), KI (integral), and KD (derivative).

[0026] like Figure 2 The figure shows a typical unit step response process of the CPA servo control system in this invention. The curve is divided into five regions, I to V. In regions I, III, and V, the motor position is approaching the given value, and the absolute value of the error e is continuously decreasing. In regions II and IV, the motor position is moving away from the given value, and the absolute value of the error e is continuously increasing. Therefore, in regions I, III, and V, it is desirable for the motor to approach the given value as quickly as possible to accelerate the response speed; however, an excessively fast approach speed will further lead to regions II and IV. In regions II and IV, it is desirable for the error of the servo control system to continuously increase and quickly transform into an output value approaching the input value.

[0027] When in region I, e>0 and ec<0, it indicates that the motor is rising rapidly but has not reached the set value. However, overshoot may occur later. Therefore, a larger KP should be set to speed up the response, and KI should be set to 0 to avoid the continuous accumulation of the integral term. At the same time, since ec<0 in this stage, the value of the derivative term is negative. Adding the derivative term will reduce the control output, thereby suppressing the rising speed. Therefore, a certain KD should be set to make the negative value of the derivative term larger, thereby making the suppression effect stronger and avoiding overshoot.

[0028] In region II, e < 0 and ec < 0, indicating that overshoot has occurred and continues to rise, which needs to be suppressed; otherwise, the system will have an overshoot tendency. At this time, KP should be decreased to reduce the control action. Furthermore, since the integral action accumulates negative errors, causing the control output value to deviate further from the input value and pushing the system output value to rise further, KI is set to 0. At this time, ec < 0, and the derivative term is negative. Increasing KD will further reduce the control output value, suppressing the upward trend; therefore, KD should be increased at this time.

[0029] In region III, e < 0, ec > 0, indicating that although there is still overshoot, the system has regressed towards the setpoint. However, the system output needs to decrease smoothly to avoid undershoot due to excessively rapid decline. Since ec > 0, the derivative term is positive, which increases the control output and slows down the decline. However, to avoid undershoot due to excessively rapid decline, KD should be decreased. To ensure a smooth decline in the system output, KP can be set to a small value. Because the error is positive, the integral will accumulate, but the system should avoid excessive accumulation of integrals during the regression process, which could lead to undershoot. Therefore, KI is still set to 0.

[0030] In region IV, e>0 and ec>0, indicating that the output value is already lower than the set value and is still decreasing, suggesting a downward trend in the system. At this point, the proportional action is positive (e>0), which helps the output to rise, but the actual value is still decreasing (the error is increasing), so KP needs to be increased to prevent further decline. The integral action is positive (the integral of the error), which gradually increases the control output, so a certain KI value is set to help improve the control effect. Since ec>0, the derivative action is positive, which increases the control output. The derivative action is beneficial at this point, but when the descent speed is fast, ec becomes very large, and an overly strong derivative action may lead to excessive control input, causing overshoot during the subsequent rise. Therefore, KD should be appropriately reduced.

[0031] When in region V, e>0, ec<0, indicating that the system output value is constantly approaching the input value. At this time, the proportional action can be slightly reduced to avoid rising too quickly; the integral action should be increased to eliminate steady-state error; to avoid overshooting again, KD should be maintained at a small value to reduce suppression and reach the setpoint more quickly.

[0032] Therefore, specifically in this embodiment, five rules are set in the typical unit step response process of the CPA servo control system, including: Region I, Rule 1, for the accelerated sprint phase: increase the proportional and differential effects, and make the integral effect zero; Region II, Rule 2, is the overshoot emergency braking phase. It reduces the proportional action, makes the integral action zero, and increases the differential action. Region III, the third rule, is the inertial natural fall-off stage, which reduces proportional and differential actions, making the integral action zero; Region IV, Rule 4, is for the downslope interception phase, increasing proportional and integral action and reducing differential action; In region V, the fifth rule, which is the convergence phase, reduces the proportional effect, significantly increases the integral effect, and keeps the differential effect small.

[0033] The control process described above is divided into regions based on time, but in practice, the exact temporal sequence of the control process cannot be obtained. Therefore, regions should be divided using states (e and ec). However, this method of division can easily confuse regions I and V. Therefore, a preset rate of change threshold needs to be set. When e > 0, ec < 0 and is greater than the preset rate of change threshold, it is considered to be in region I; otherwise, it is considered to be in region V.

[0034] In a preferred embodiment of the present invention, the PID adaptive control algorithm is summarized as follows: in, , , These are the final parameter values ​​of the PID controller; , , These are the standard parameter values ​​for the PID controller; This is the standard value for variation in region II, used to dynamically adjust based on the magnitude of the error e. Final parameter value; for The upper limit is to prevent An excessively large value causes the PID control system to diverge.

[0035] For region I: The values ​​2.5 and 0.2 are adjustable parameters and are only examples.

[0036] For Region II: The values ​​0.5 and 2.0 are adjustable parameters and are only examples here.

[0037] For Region III: ; Among them, if ,but Furthermore, 0.5 and 0.95 are adjustable parameters; they are only examples here.

[0038] For Region IV: Among them, 0.7 and 0.5 are adjustable parameters, and are only examples here.

[0039] For region V: Among them, if ,but Furthermore, 0.7 and 0.5 are adjustable parameters; they are only examples here.

[0040] Furthermore, since the drive of spaceborne CPAs often uses FPGAs to generate space vector pulse width modulation signals to control the inverter, the switching characteristics of the pulse width modulation wave, insufficient or mismatched dead time, poor connection of the dead time calculation model, changes in commutation frequency due to speed changes, and motor current harmonics can all be superimposed and transmitted layer by layer, causing vibration of the CPA. Therefore, in this invention, a dead time dynamic adjustment module is used to achieve dynamic matching and connection of dead time, and a full-band harmonic compensation module is used to achieve dynamic compensation of motor current harmonics, thereby achieving vibration resistance during CPA operation.

[0041] The dead time dynamic adjustment module can divide the mechanical angular velocity into an extremely low speed range (0.001-0.01° / s), an ultra-low speed range (0.01-1° / s), and a normal low speed range (1-5° / s), and generate corresponding PWM dead time according to different speed ranges.

[0042] During the extremely low-speed phase, the dead time is calculated using the following formula: The formula for calculating dead time in the ultra-low speed range (0.01-1° / s) is: The formula for calculating dead time in the normal low-speed range (1-5° / s) is: in, Dead time; The proportionality coefficient was obtained through experimental calibration. In the extremely low and ultra-low speed range of 0.001-1° / s, the dead time and torque pulsation at different speeds were tested to ensure that the ratio of dead time to commutation cycle at each speed was stable between 0.1% and 0.5%. This range is the optimal range that takes into account both voltage distortion and switching safety. It is the mechanical rotation angle; To avoid the denominator of the formula being 0 when the mechanical angle approaches 0; The minimum dead time for the power transistor safety switch is determined based on the datasheet parameters of the selected inverter power device (such as IGBT). The dead zone correction coefficient is determined through comparative experiments for the extremely low speed range (0.001-0.01° / s). In this speed range, without correction, the insufficient dead time easily leads to an increase in current distortion rate. After adding the dead zone correction coefficient, the distortion rate can be effectively reduced and a smooth transition can be achieved to the dead zone calculation model for speed ranges above 0.01° / s. This is the critical characteristic velocity for the extremely low speed range and the ultra-low speed range, consistent with the segmentation threshold (0.01° / s) of the speed grading module, ensuring that when... When the value is 0.01° / s, the dead time is smoothly transitioned to the calculated value of the ultra-low speed segment to avoid sudden parameter changes at the segmentation point; The linear adjustment coefficient for the dead time in the normal low-speed range (1-5° / s) is determined based on the motor speed and commutation error, and is tested under different conditions. The vibration amplitude at the specified value ensures that the commutation torque pulsation amplitude at each speed is stable between 3% and 5% of the rated torque, and can be smoothly connected with the dead time of the ultra-low speed range. The minimum dead time in the normal low-speed range is determined by the switching characteristics of the inverter's power devices and the high-speed commutation requirements.

[0043] Furthermore, the full-band harmonic compensation module includes a multi-resolution decomposition unit and a segmented compensation command generation unit, which work together. The multi-resolution decomposition unit is responsible for extracting harmonic components of different frequency bands from the motor's dq-axis current. The segmented compensation command generation unit generates targeted compensation current commands based on the harmonic order and speed segment characteristics. Reverse harmonics are injected through the current loop to cancel the electromagnetic force fluctuations of the original harmonics, thereby controlling the vibration amplitude and achieving accurate cancellation of the 3rd, 6th, 12th and above harmonics.

[0044] The multi-resolution decomposition unit is used to implement a hierarchical processing strategy for the harmonic characteristic differences of different speed ranges from 0.001 to 5° / s; in the extremely low speed range of 0.001 to 0.01° / s, layered wavelet packet decomposition is used; in the medium and low speed range of 0.01 to 5° / s, fast Fourier transform is used.

[0045] Specifically, in the extremely low speed range of 0.001-0.01° / s, the motor speed is extremely low, mainly generating 3rd and 6th low-frequency harmonics with a vibration frequency of 0.1-1Hz, and the harmonic amplitude fluctuates significantly with the speed. At this point, using 8-layer wavelet packet decomposition and selecting the db4 wavelet basis function, the current signal is decomposed to a frequency band resolution of 0.01Hz, which can accurately extract the 3rd and 6th harmonics within the 0.1-1Hz range. The specific formula is as follows: in, The amplitude of the harmonic components; The phase of the harmonic components; The reconstructed harmonic time-domain signal; This represents the imaginary part of the Fourier transform; is the real part of the Fourier transform; This represents the number of sampling points.

[0046] Specifically, in the low-to-medium speed range of 0.01-5° / s, as the rotational speed increases, the proportion of higher harmonics (12th and above, frequency 1-200Hz) increases, in addition to the 3rd and 6th harmonics, and the harmonic frequency is linearly correlated with the rotational speed. At this point, using Fast Fourier Transform (FFT), with a sampling frequency of 1kHz, a window length of 1024 points, and a frequency resolution of 0.976Hz, the 3rd, 6th, 12th, and above harmonics within the 1-200Hz range can be efficiently extracted. The specific formula is as follows: in, The frequency of the h-th harmonic is... , The electric frequency of the motor; For frequency Fourier transform value at; The number of FFT points.

[0047] The segmented compensation command generation unit is used to generate differentiated compensation commands based on the harmonic order and the dynamic characteristics of the velocity segment, so as to avoid the compensation process from causing new vibrations.

[0048] Specifically, for the 3rd and 6th harmonics, if the compensation current is suddenly injected, it may resonate with the natural frequency of the mechanical structure, amplifying the vibration. In this case, a gradual compensation method is used, with the command current gradually increasing from 0 to the target value. The specific compensation formula is as follows: in, The current for compensation; The compensation coefficient is a constant in the range of 0-1. It needs to be calibrated by test to avoid current overshoot caused by overcompensation, and the overshoot needs to be controlled within 10%. Since it is a time constant, it needs to be experimentally calibrated to ensure that the compensation current is within the specified range. The target value was reached smoothly within the specified range.

[0049] Specifically, for harmonic compensation of the 12th order and above, since the harmonic frequency is high and the motor has a fast dynamic response in the 0.01-5° / s range, a direct compensation method can be used. The specific compensation formula is as follows: in, The compensation coefficient is a constant in the range of 0-1 and needs to be calibrated experimentally. Because high-frequency harmonics decay quickly, it is necessary to ensure that the amplitude of the 12th harmonic is reduced significantly while the compensation is completed quickly.

[0050] Furthermore, the aforementioned vibration prevention and resistance schemes enable the CPA to operate stably under conditions free from external interference. However, in actual spaceborne environments, external environmental interference can cause even a stably operating CPA to vibrate. Therefore, rapidly suppressing vibration and quickly restoring the CPA to a stable state is crucial. This invention adds an enhanced detection mode to the existing full-band harmonic compensation module and combines graded response and dynamic parameter feedback adjustment to achieve rapid vibration suppression.

[0051] The enhanced detection mode includes multi-dimensional vibration feature extraction and vibration level classification.

[0052] The multi-dimensional vibration feature extraction involves detecting the vibration amplitude of the CPA. When the detected vibration amplitude exceeds a preset vibration amplitude threshold (e.g., 12 μrad for the 0.001-0.01° / s range and 10 μrad for the 0.01-5° / s range), an enhanced detection mode is triggered. Within the 0.001-0.01° / s range, the wavelet packet decomposition layer is increased to 10 layers to improve the frequency band resolution. Within the 0.01-5° / s range, the FFT window length is shortened to quickly locate the harmonic order (3rd, 6th, 12th and above) and frequency corresponding to the vibration source.

[0053] The vibration level classification is based on the ratio of the vibration amplitude to a preset vibration amplitude threshold, dividing the vibration into three levels: Mild vibration (1-1.5 times the preset vibration amplitude threshold): dominated by a single harmonic component (e.g., the amplitude of the 3rd harmonic is slightly exceeded). Moderate vibration (1.5-2 times the preset vibration amplitude threshold): superposition of multiple harmonic components (such as 3rd + 6th harmonics); Severe vibration (>2 times the preset vibration amplitude threshold): Harmonic coupling with mechanical resonance (e.g., the 12th harmonic frequency is close to the structure's natural frequency).

[0054] Specifically, after classifying the vibration levels, a graded response strategy is set for different vibration levels: For mild vibrations (targeting a single harmonic), specifically low-frequency vibrations caused by the 3rd or 6th harmonic, the segmented compensation command generation unit activates the compensation intensity enhancement mechanism, maintaining the gradual compensation framework and increasing the compensation coefficient. shorten the time constant Improve the efficiency of reverse cancellation; directly increase the compensation coefficient for high-frequency vibrations caused by 12th and higher harmonics. By instantaneously increasing the reverse current, the vibration energy is rapidly attenuated.

[0055] For moderate vibration (for multiple harmonic superposition), i.e. vibration with superposition of the 3rd and 6th harmonics, a timing compensation strategy is adopted. The 6th harmonic compensation is started first, and the 3rd harmonic compensation is started 100ms later to avoid the superposition of current fluctuations caused by simultaneous compensation. For vibration with superposition of the 6th and 12th harmonics, the compensation intensity of both is increased simultaneously.

[0056] For severe vibration (targeting harmonic and mechanical resonance coupling), the CPA speed is first temporarily reduced by 30% via the motor drive module to decrease harmonic excitation energy; simultaneously, the full-band harmonic compensation module enters saturation compensation mode, targeting the 3rd and 6th harmonics. Setting it to 1 will target harmonics of the 12th order and above. Set to 1, and at the same time shorten the compensation instruction update cycle by half to achieve high-frequency reverse cancellation.

[0057] Furthermore, in the enhanced mode, the vibration decay rate is simultaneously detected. If the vibration decay rate is less than a preset vibration decay rate threshold, the compensation coefficient is further increased. or If overcompensation occurs, i.e., vibration reverse overshoot, then the compensation coefficient should be appropriately reduced and the extension period should be extended. Alternatively, shortening the FFT window length can ensure that the vibration converges stably to within the vibration decay rate threshold; this process is known as dynamic parameter feedback adjustment.

[0058] Furthermore, when the vibration amplitude is lower than the preset vibration amplitude threshold for three consecutive control cycles, the full-band harmonic compensation module automatically exits the enhancement mode and the compensation parameters are restored to normal values, thus avoiding the decrease in motor efficiency caused by long-term strong compensation.

[0059] In summary, the present invention provides a vibration suppression and anti-vibration method for a spaceborne coarse pointing mechanism (CPA). Based on software implementation, and targeting the specific usage scenarios of spaceborne CPAs, it employs an experience-based PID adaptive control algorithm to prevent transient oscillations during the CPA startup phase, thereby achieving vibration prevention. A dead-time dynamic adjustment module and a full-band harmonic compensation module are used to achieve dynamic matching and connection of dead time and dynamic compensation of motor current harmonics, thus achieving vibration resistance during CPA operation. By adding a strong-mode detection mode to the full-band harmonic compensation module to detect vibration amplitude, classify vibration levels, and adopt a strategy combining graded response and dynamic parameter feedback adjustment for different vibration levels, vibration suppression during CPA operation is achieved, demonstrating significant advantages.

[0060] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for vibration suppression and resistance of a spaceborne coarse pointing mechanism, characterized in that, include: Vibration prevention during CPA operation is achieved by dynamically adjusting the proportional parameter KP, integral parameter KI, and derivative parameter KD through a PID adaptive control algorithm. The dead time is dynamically matched and connected by a dead time dynamic adjustment module, and the motor current harmonics are dynamically compensated by a full-band harmonic compensation module, thus achieving vibration resistance during CPA operation. By adding a strong-mode detection mode to the full-band harmonic compensation module, vibration amplitude is detected, vibration levels are classified, and a strategy combining graded response and dynamic parameter feedback adjustment is adopted for different vibration levels to achieve vibration suppression during CPA operation.

2. The vibration suppression and anti-vibration method for a spaceborne coarse pointing mechanism as described in claim 1, characterized in that, The PID adaptive control algorithm includes: The IV control region is divided based on the error e and the rate of change of error ec. For region I, where e>0 and ec<0 and |ec|> the preset rate of change threshold, the following rules are set: increase KP, set KI=0, and increase KD; For region II, where e < 0 and ec < 0, set the following rules: decrease KP, set KI = 0, and increase KD; For region III, where e < 0 and ec > 0, set the rule: decrease KP and KD, and set KI = 0; For region IV, where e>0 and ec>0, set the rule: increase KP and KI, decrease KD; For region V, where e>0 and ec<0 and |ec|≤ preset rate of change threshold, the rule is set to decrease KP, increase KI, and maintain KD.

3. The vibration suppression and anti-vibration method for a spaceborne coarse pointing mechanism as described in claim 1, characterized in that, The dead time dynamic adjustment module divides the mechanical angular velocity into extremely low speed range, ultra-low speed range and normal low speed range, and generates corresponding dead time according to different speed ranges.

4. The vibration suppression and anti-vibration method for the spaceborne coarse pointing mechanism as described in claim 3, characterized in that, The dead time calculation formula for the extremely low speed range is as follows: The formula for calculating the dead time in the ultra-low speed range is: The dead time calculation formula for the normal low-speed range is: in, Dead time; This is the proportionality coefficient; It is the mechanical rotation angle; It is a constant; This is the minimum dead time for the power transistor's safety switch; This is the dead zone correction factor for the extremely low speed range; This refers to the critical characteristic speed between the extremely low speed range and the ultra-low speed range. This is the linear adjustment coefficient for the dead time in the normal low-speed range; This is the minimum dead time in the normal low-speed range.

5. The vibration suppression and anti-vibration method for the spaceborne coarse pointing mechanism as described in claim 3, characterized in that, The extremely low speed range corresponds to 0.001-0.01° / s; the ultra-low speed range corresponds to 0.01-1° / s; and the normal low speed range corresponds to 1-5° / s.

6. The vibration suppression and anti-vibration method for a spaceborne coarse pointing mechanism as described in claim 1, characterized in that, The full-band harmonic compensation module includes: A multi-resolution decomposition unit is used to extract harmonic components of different frequency bands from the motor. The segmented compensation command generation unit is used to generate targeted compensation current commands based on the harmonic order and speed segment characteristics, and to cancel the electromagnetic force fluctuations of the original harmonic by injecting reverse harmonics, thereby controlling the vibration amplitude and achieving precise harmonic cancellation.

7. The vibration suppression and anti-vibration method for a spaceborne coarse pointing mechanism as described in claim 6, characterized in that, The full-band harmonic compensation module is equipped with an enhanced detection mode; the enhanced detection mode includes multi-dimensional vibration feature extraction and vibration level classification; The multi-dimensional vibration feature extraction is used to detect the vibration amplitude of CPA; and the vibration level is classified according to the ratio of the vibration amplitude to the preset vibration amplitude threshold.

8. The vibration suppression and anti-vibration method for the spaceborne coarse pointing mechanism as described in claim 7, characterized in that, The vibration levels include: Mild vibration, consisting of a single harmonic component, with a magnitude of 1-1.5 times the preset vibration amplitude threshold; Moderate vibration is caused by the superposition of multiple harmonic components, and its magnitude is 1.5-2 times the preset vibration amplitude threshold. Severe vibration is caused by the coupling of harmonics and mechanical resonance, and its magnitude is greater than twice the preset vibration amplitude threshold.

9. The vibration suppression and anti-vibration method for a spaceborne coarse pointing mechanism as described in claim 7, characterized in that, The enhanced detection mode can detect the vibration decay rate for dynamic parameter feedback adjustment. If the vibration decay rate is less than the preset vibration decay rate threshold, the compensation coefficient is increased; if the compensation is excessive, the compensation coefficient is decreased, and the time constant is extended or the fast Fourier transform window length is shortened.

10. The vibration suppression and anti-vibration method for a spaceborne coarse pointing mechanism as described in claim 8, characterized in that, If the vibration amplitude remains below the preset vibration amplitude threshold for three consecutive control cycles, the enhanced detection mode will be exited and the compensation parameters will be restored to normal values.

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