A method for distributing and suppressing vibration errors of an airborne suspended beam pointing mechanism

Abstract

The application relates to a vibration error distribution and suppression method of an airborne suspension type light beam pointing mechanism, and belongs to the technical field of photoelectric detection. The method steps comprise the following: determining a shear frequency range of a servo system; judging whether the light beam pointing mechanism meets the requirements by adopting wide-frequency vibration excitation; recording frequency points of resonance and amplification rates corresponding to the resonance points by adopting wide-frequency vibration excitation; obtaining light axis jitter amounts generated by each frequency point of resonance by adopting fixed-frequency vibration excitation, and sorting the light axis jitter amounts according to the sizes of the light axis jitter amounts; placing the servo system in an open loop state, exciting the light beam pointing mechanism again, obtaining light axis jitter amounts generated by each frequency point of resonance, and sorting the light axis jitter amounts according to the sizes of the light axis jitter amounts; comparing the differences between the light axis jitter amounts obtained twice, judging the reasons for the light axis jitter, and compensating the vibration error of the light beam pointing mechanism. The application effectively improves the precision of the suspension type light beam pointing mechanism and improves the detection capability of photoelectric products.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photoelectric detection, and particularly relates to a vibration error distribution and suppression method for an airborne suspension type light beam pointing mechanism. BACKGROUND

[0002] The main feature of the airborne photoelectric pod is to adopt a standard mounting structure, and the load for various tasks can be flexibly mounted without changing the structure and hardware interface of the carrier aircraft. The airborne photoelectric pod has a large length-diameter ratio, and the vibration load and aerodynamic load transmitted by the suspension bracket are a complex vibration condition with large vibration intensity and long duration. The vertical vibration and lateral vibration are generally large, and the pod generally has the characteristics of axisymmetric structure, so only the vertical vibration can be considered. The main task of the airborne suspension type light beam pointing mechanism is to isolate the carrier base and aerodynamic disturbance, and to ensure that the optical axis is stably pointed in the inertial space. However, with the improvement of the performance of the photoelectric load, higher requirements are put forward for the light beam pointing mechanism.

[0003] The vibration problem caused by the spatial large-size geometric arrangement of multiple optical elements in the traditional airborne suspension type light beam pointing mechanism is relatively obvious, and the phases of multiple optical elements in the vibration environment are difficult to keep consistent. In the actual system, the suspension type light beam pointing mechanism can be regarded as an elastic body with multiple degrees of freedom. The system model obtained by theoretical modeling is only an abstraction of the internal mechanism, and cannot accurately reflect all characteristics of the system. The error of the numerical model finite element simulation method is large, especially the estimation deviation of the harmonic peak value of the natural frequency point in the random vibration is large, and it is difficult to effectively improve the precision of the light beam pointing mechanism.

[0004] Therefore, the present application provides a vibration error distribution and suppression method for an airborne suspension type light beam pointing mechanism. SUMMARY

[0005] The technical problem to be solved is:

[0006] In order to avoid the shortcomings of the prior art, the present application provides a vibration error distribution and suppression method for an airborne suspension type light beam pointing mechanism, which analyzes the overall vibration response of each optical element in the airborne suspension type light beam pointing mechanism, the vibration phase deviation between each optical element, and the error distribution of different frequency bands, and processes and compensates them respectively in combination with the bandwidth design requirements of the light beam pointing mechanism servo system, so that high-quality light beam pointing effect can be obtained.

[0007] The technical scheme of the present application is: a vibration error distribution and suppression method for an airborne suspension type light beam pointing mechanism, the light beam pointing mechanism adopts a servo system control, receives the feedback signal of the sensor through the servo system, and adjusts the position and direction of the light beam pointing mechanism in real time to ensure that the light beam can accurately and correctly point to the target; the specific steps are as follows:

[0008] According to the performance requirement of the light beam pointing mechanism, the shear frequency range of the servo system is determined;

[0009] The light beam pointing mechanism is excited in a wide frequency vibration mode to obtain the jitter amount of the optical axis in two directions in the imaging picture, the total jitter amount is calculated and compared with an error threshold, when the total jitter amount is less than or equal to the error threshold, the requirement is met; when the total jitter amount is greater than the error threshold, the following steps are continued;

[0010] The light beam pointing mechanism is excited in a wide frequency vibration mode, and an acceleration sensor is used to measure the response of the light beam pointing mechanism, the frequency point at which resonance occurs and the amplification ratio corresponding to the resonance point are recorded;

[0011] The light beam pointing mechanism is excited in a fixed frequency vibration mode to obtain the optical axis jitter amount generated by each frequency point at which resonance occurs, and the optical axis jitter amount is sorted according to the size;

[0012] The servo system is placed in an open loop state, the light beam pointing mechanism is excited again, the optical axis jitter amount generated by each frequency point at which resonance occurs is obtained, and the optical axis jitter amount is sorted according to the size;

[0013] The difference between the above two optical axis jitter amounts is compared, when the difference between the optical axis jitter amounts is greater than a set jitter amount threshold, it is determined that the reason for the optical axis jitter is that the stability margin of the servo system is insufficient; when the difference between the optical axis jitter amounts is less than or equal to the set jitter amount threshold, it is determined that the reason for the optical axis jitter is that the elasticity of a certain optical element of the light beam pointing mechanism is relatively large, or there is one or several relatively large resonance peaks in the whole platform;

[0014] Based on the determined reason for the optical axis jitter, the vibration error of the light beam pointing mechanism is compensated;

[0015] The above steps are repeated until the performance of the light beam pointing mechanism under the vibration environment meets the requirements.

[0016] A further technical solution of the present application is that the shear frequency ω c The determined condition is that the open loop frequency characteristic amplitude at the working frequency ω k of the light beam pointing mechanism is greater than or equal to the ratio of the output angle θ max to the maximum error e max , that is, |G(jω k )|≥θ max / e max ; and the phase angle margin at the shear frequency ω c is between 40° and 60°.

[0017] A further technical solution of the present application is that the jitter amounts of the optical axis in two directions in the imaging picture are Δx and Δy respectively, and the recording duration should be more than 1 min; and the formula of the total optical axis jitter amount Δ is as follows:

[0018]

[0019] In the formula, i represents the number of sampling in the recording duration, and n represents the total number of sampling in the recording duration;

[0020] The error threshold is set as e max When Δ≤e max , the requirement is met.

[0021] A further technical solution of the present application is that the frequency points of resonance are recorded as f1, f2, …, f n , and the amplification factors corresponding to the resonance points are recorded as A1, A2, …, A n .

[0022] A further technical solution of the present application is that when the light beam pointing mechanism is excited in a fixed frequency vibration mode, the light axis jitter amount generated by each frequency point of resonance in a non-open loop state is Δ a1 , Δ a2 , …, Δ an ; the light axis jitter amount generated by each frequency point of resonance in an open loop state is Δ b1 , Δ b2 , …, Δ bn ; and the difference between the light axis jitter amounts in the two states is Δ a1 -Δ b1 , Δ a2 -Δ b2 , …, Δ an -Δ bn .

[0023] A further technical solution of the present application is that the jitter threshold is

[0024] A further technical solution of the present application is that the method for compensating the vibration error of the light beam pointing mechanism is:

[0025] When it is determined that the cause of the light axis jitter is the insufficient stability margin of the servo system, the compensation is performed by adjusting the control parameters;

[0026] When it is determined that the cause of the light axis jitter is that the elasticity of a certain optical element of the light beam pointing mechanism is large, the compensation is performed by reinforcing the optical element to increase the rigidity;

[0027] When it is determined that the cause of the light axis jitter is that there is one or several large resonance peaks in the whole platform, the compensation is performed by increasing the damping or the vibration absorber to weaken the resonance peaks;

[0028] The above three measures are implemented independently or jointly.

[0029] The further technical scheme of the present application is that when the compensation is performed by adjusting the control parameter, a differential correction network is adopted Wherein, T represents a time constant; s represents a Laplace operator; and alpha represents an adjustment coefficient.

[0030] Alpha is less than 1, and the adjustment coefficient alpha is decreased from 1 to an appropriate degree, so as to increase the stability margin of the servo system.

[0031] The further technical scheme of the present application is that the vibration absorber is composed of a spring-damper-mass block, and the adjustment of the spring and the mass block can adjust the resonance point frequency and the amplification ratio, until the optical axis jitter of the beam pointing mechanism at the resonance point is attenuated to less than an error threshold.

[0032] The vibration error distribution and suppression system of the airborne suspension type beam pointing mechanism comprises a beam pointing mechanism, an excitation module, a stability margin adjustment module and a vibration absorber.

[0033] The excitation module is used for applying wideband vibration or fixed-frequency vibration to the beam pointing mechanism, recording the frequency points at which resonance occurs and the amplification ratios corresponding to the resonance points, and obtaining the optical axis jitter amount generated by each frequency point at which resonance occurs.

[0034] The stability margin adjustment module is used for adjusting the control parameter and performing compensation for insufficient stability margin.

[0035] The vibration absorber is used for weakening the resonance peak and performing compensation for a large resonance peak.

[0036] Beneficial effects

[0037] The beneficial effects of the present application are that the vibration error distribution and suppression method of the airborne suspension type beam pointing mechanism can distribute and sort the vibration response on the basis of the existing beam pointing mechanism, analyze the frequencies that have obvious influences on the beam pointing, supplement the damping link or the vibration absorber, and can specifically suppress the beam jitter caused by the phase difference of the frequency response of the optical element, effectively improve the precision of the suspension type beam pointing mechanism, and improve the detection capability of the photoelectric product.

[0038] The method of the present application uniformly disposes the vibration transmission, error distribution, pointing precision control and vibration response compensation of the airborne pod suspension type pointing mechanism, adopts multiple measures, distributes the vibration response errors of different frequency bands on the basis of no great change of the overall structure, divides the low frequency band, the medium frequency band and the high frequency band according to the servo system precision requirement, optimizes and reinforces the parts in the low frequency band, increases the damping ratio or the vibration absorber to reduce the resonance peak in the medium frequency band, and reduces the vibration in the high frequency band to realize the compensation of the vibration response error, so as to obtain high-quality beam pointing control effect, improve the dynamic performance of the airborne pod optical axis pointing, and has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 A vibration error transfer distribution diagram of the suspended beam pointing mechanism is listed,

[0040] Figure 2 A relationship diagram of the servo system and resonance is listed,

[0041] Figure 3 A compensation link and resonance improvement schematic diagram is listed.

[0042] The reference signs are explained as follows: 1. a hanger, 2. a beam pointing mechanism, 3. a target, 4. an optical element, 5. a vibration absorber, 6. an optoelectronic load mounting surface, and 7. a damper. DETAILED DESCRIPTION

[0043] The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0044] The system model obtained by theoretical modeling based on the prior art is only an abstraction of the internal mechanism and cannot accurately reflect all characteristics of the system, and the numerical model finite element simulation method has a large error, especially in the estimation of the resonance peak value at the inherent frequency point in random vibration, and it is difficult to effectively improve the accuracy of the beam pointing mechanism. With the existing test means and data processing method, the vibration excitation of the distributed characteristics of the beam pointing mechanism is confirmed, the pointing stiffness distribution of the suspended beam pointing mechanism under the vibration environment is confirmed, the frequency bands and optical elements that have a significant impact on the beam pointing are identified, and the low-frequency region of the individual optical elements is reinforced, the damping is increased in the medium-frequency region to reduce the resonance peak value, and the vibration absorber is reduced or increased in the high-frequency region. The phase difference between the optical elements in the pointing mechanism is reduced, and the beam pointing accuracy is improved. The beam pointing mechanism adopts a servo system control, receives the feedback signal of the sensor through the servo system, and adjusts the position and direction of the beam pointing mechanism in real time to ensure that the beam can accurately point to the target; the specific operation is as follows:

[0045] 1) Distribution of beam pointing mechanism vibration error. In the low-frequency band (generally less than 0.1ω c ), it is mainly linear vibration, and the responses of the optical elements in the mechanism are basically consistent, and no significant phase difference is generated, and the error of the long-distance target detection can be ignored; in the medium and high frequency band, a certain number of resonance peaks are generated, and the stability of the servo system is affected, and the resonance peaks allowed to appear cannot exceed the relative stability margin requirement of the servo system.

[0046] 2) Measurement of the degree of influence of vibration on the optical axis pointing. Vibration excitation is applied to the beam pointing mechanism, and the optical axis jitter is observed, and the test adopts a wide frequency vibration or a fixed frequency vibration.

[0047] 3) Determine the effect of resonance on the servo system. Determine which kind of effect of resonance on the servo system: one is that the system with low stability margin is prone to instability when vibrating, and the other is that the high resonance peak will make some frequency response become extremely large, and the interference increases, so that the system accuracy decreases sharply to exceed the linear region. By changing the vibration excitation value, the response value of the servo system at the resonance point is observed, so that it can be distinguished whether the servo system has resonance or is disturbed greatly.

[0048] 4) Light axis pointing error compensation when vibrating. If the problem occurs in the low frequency band, it is caused by loosening or low installation stiffness of individual optical elements, so reinforcement compensation can be made; when resonance occurs in the medium frequency band, the peak value of the resonance point should be measured, when the resonance peak is low, the servo system parameters should be adjusted appropriately to enhance the stability margin, and when the resonance peak is high, the damping or vibration absorber at the resonance point should be increased appropriately to change the narrow peak into a wide peak; when resonance occurs in the high frequency region, damping measures should be taken to reduce the damage of high frequency vibration to the components. Since resonance in the high frequency region is easy to judge and supplement, the technical scheme of the present application is mainly for judging and supplementing in the low and medium frequency bands.

[0049] Based on the above analysis, the specific steps of the vibration error distribution and suppression method of the airborne suspension type light beam pointing mechanism are as follows:

[0050] Step 1: According to the performance requirements of the light beam pointing mechanism, the shear frequency range of the servo system is determined;

[0051] Step 2: The light beam pointing mechanism is excited by using wide frequency vibration, the jitter amount of the optical axis in two directions in the imaging picture is obtained, the total jitter amount is calculated and compared with the error threshold value, when the total jitter amount is less than or equal to the error threshold value, the requirement is met; when the total jitter amount is greater than the error threshold value, the following steps are continued;

[0052] Step 3: The light beam pointing mechanism is excited by using wide frequency vibration, and an acceleration sensor is used to measure the response of the light beam pointing mechanism, the frequency point at which resonance occurs and the amplification ratio corresponding to the resonance point are recorded;

[0053] Step 4: The light beam pointing mechanism is excited by using fixed frequency vibration, the optical axis jitter amount generated by each frequency point at which resonance occurs is obtained, and the optical axis jitter amount is sorted according to the size;

[0054] Step 5: The servo system is placed in an open loop state, the light beam pointing mechanism is excited again, the optical axis jitter amount generated by each frequency point at which resonance occurs is obtained, and the optical axis jitter amount is sorted according to the size;

[0055] Step 6: compare the difference between the two optical axis jitter amounts, when the difference between the optical axis jitter amounts is greater than a set jitter threshold, then determine that the cause of the optical axis jitter is insufficient stability margin of the servo system; when the difference between the optical axis jitter amounts is less than or equal to the set jitter threshold, then determine that the cause of the optical axis jitter is that a certain optical element of the beam pointing mechanism has a relatively large elasticity, or that there is one or several relatively large resonance peaks in the entire platform;

[0056] Step 7: based on the determined cause of the optical axis jitter, compensate for the vibration error of the beam pointing mechanism;

[0057] Step 8: repeat the above steps until the beam pointing performance under vibration meets the requirements.

[0058] The airborne suspension type beam pointing mechanism vibration error distribution and suppression system of the application comprises a beam pointing mechanism, an excitation module, a stability margin adjustment module and a vibration absorber; the excitation module applies wideband vibration or fixed frequency vibration to the beam pointing mechanism, records the frequency points at which resonance occurs and the amplification ratio of the corresponding resonance points, and obtains the optical axis jitter amount generated by each frequency point at which resonance occurs; the stability margin adjustment module adjusts the control parameters to compensate for insufficient stability margin; and the vibration absorber weakens the resonance peak to compensate for a relatively large resonance peak.

[0059] According to the accuracy requirements of the beam pointing mechanism, the amplitude-phase frequency characteristics of the servo system are determined, and then the degree of resonance that the mechanism can tolerate is determined, the vibration error-frequency distribution is obtained by exciting the modal of each optical element of the beam pointing mechanism through vibration excitation, and then the inherent frequency and its resonance peak are compensated for by increasing the damping or the vibration absorber, thereby effectively improving the method for improving the optical axis jitter of the suspension type beam pointing mechanism.

[0060] The above technical solutions are further described below with reference to the accompanying drawings:

[0061] Referring to Figure 1 , the vibration error of the suspension type beam pointing mechanism can be approximated as an elastic body composed of multiple mass blocks, dampers and springs. Each optical component can be regarded as a small elastic body, and the beam enters the image plane after being reflected or transmitted by each optical unit. With the beam propagation direction as the axis, the elastic body formed by each optical element of the beam pointing mechanism contributes to the influence on the pointing accuracy of the optical axis.

[0062] Referring to Figure 2 , the servo system bandwidth that meets the accurate pointing performance requirements is determined. On the left side of the shear frequency ω c , it belongs to the low frequency region (generally less than 0.1ω c), the disturbance caused by vibration can be inhibited to a considerable extent, and in the low frequency region, the multiple optical elements constituting the beam pointing mechanism can be approximately regarded as rigid bodies, the amplitude and phase deviation of vibration response between the optical elements are extremely small, and no obvious angular motion is caused, so that the influence on the optical axis is extremely small; the shear frequency ω c belongs to the medium frequency band (generally 0.1ω c ~ 5ω c ), and the size of the resonance peak affects the relative stability of the servo system; in the high frequency region (generally 5ω c ), the vibration amplitude is relatively small, and the influence of vibration on the reliability of the components is mainly considered.

[0063] Referring to Figure 3 , the compensation effect of the resonance point and the resonance peak after adding damping or vibration absorber is shown.

[0064] For the airborne suspended beam pointing mechanism, the vibration error distribution and compensation are relatively complex. The specific implementation steps are as follows:

[0065] First, according to the performance requirements of the beam pointing mechanism, the shear frequency (ω c ) range of the servo system is determined. The selection of the shear frequency should ensure that the open loop frequency characteristic amplitude at the working frequency ω k of the accurate pointing mechanism is greater than the ratio of the maximum error e max to the output angle θ max , that is, |G(jω k )|≥θ max / e max , and the phase angle margin at the shear frequency ω c is between 40° and 60°.

[0066] Second, the beam pointing mechanism is excited by wideband vibration, and the jitter amount Δx, Δy in the two directions of the optical axis in the imaging picture is observed, and the recording time should be more than 1 min, and the total jitter amount Δ of the optical axis should be not greater than the error e max , that is, where i represents the number of samplings in the recording time, and n represents the total number of samplings in the recording time. If the requirement is met, the following steps are not performed; if the requirement is not met, the next step is continued.

[0067] Third, the beam pointing mechanism is excited by wideband vibration, and the acceleration sensor is used to measure the structure response, and the frequency points (f1, f2, …, f n ) at which the resonance occurs and the amplification ratios (A1, A2, …, A n ) corresponding to the resonance points are recorded.

[0068] Fourth step, the fixed frequency vibration excitation light beam pointing mechanism, observation and record each resonance point produced the light axis jitter (Δ a1 , Δ a2 , …, Δ an ) according to the light axis jitter size to arrange;

[0069] Fifth step, let the servo system be in open loop state (in the premise of ensuring the mechanism safety), again excitation, observation and record each resonance point produced the light axis jitter (Δ b1 , Δ b2 , …, Δ bn ) according to the light axis jitter size to arrange;

[0070] Sixth step, compare the fourth step, the fifth step light axis jitter difference, (Δ a1 -Δ b1 ), (Δ a2 -Δ b2 ), …, (Δ an -Δ bn ), to this analysis light axis jitter reason: if the jitter difference is greater than Then can consider that the light axis jitter main reason is the servo system stability margin insufficient;Contrarily, then can contain one or two reasons below: certain optical element elasticity is bigger, the whole platform has one or several larger resonance peak.

[0071] Seventh step, the servo system stability margin insufficient can adjust control parameter to make up, can adopt the differential correction network Wherein, T indicates time constant;S indicates Laplace operator;Alpha indicates adjustment coefficient;Alpha < 1, the adjustment coefficient alpha makes it from 1 to decrease to appropriate degree, can increase the servo system stability margin;Certain optical element elasticity is bigger can structure reinforcement to increase rigidity;The whole platform has several larger resonance peak, need to increase the vibration absorber to weaken the resonance peak, the vibration absorber is composed of spring-damper-mass, adjusts spring and mass and can adjust the resonance point (f1, f2, …, f n ) frequency and amplification ratio (A1, A2, …, A n ), until the light beam pointing mechanism light axis jitter at the resonance point attenuates to the acceptable error, the vibration absorber can increase one or more for the resonance point that influences significantly.Three measures can be implemented alone, also can be implemented jointly, repeat the second step to the sixth step until the light beam pointing performance under the vibration environment meets the requirement.

[0072] Although the above has shown and described the embodiment of the present application, can understand that the above-mentioned embodiment is exemplary, cannot be understood as the limitation to the present application, the ordinary skill in the art person can change, modify, replace and change to the above-mentioned embodiment without departing from the principle and the purpose of the present application in the range of the present application.

Claims

1. A method for vibration error distribution and suppression of an airborne suspended beam pointing mechanism, wherein the beam pointing mechanism is controlled by a servo system, the servo system receives feedback signals from sensors, and adjusts the position and direction of the beam pointing mechanism in real time to ensure that the beam can accurately point to the target; characterized in that... The specific steps are as follows: The shearing frequency range of the servo system is determined based on the performance requirements of the beam pointing mechanism. A wide-frequency vibration method is used to excite the beam pointing mechanism to obtain the jitter in two directions of the optical axis in the imaging image. The total jitter is calculated and compared with the error threshold. If the total jitter is less than or equal to the error threshold, the requirement is met; if the total jitter is greater than the error threshold, the following steps are continued. A wide-frequency vibration method was used to excite the beam pointing mechanism, and an accelerometer was used to measure the response of the beam pointing mechanism. The frequency point of resonance and the amplification of the corresponding resonance point were recorded. The beam pointing mechanism is excited by constant frequency vibration, and the optical axis jitter generated at each resonant frequency point is obtained and sorted according to the magnitude of the optical axis jitter. The servo system is placed in an open-loop state, and the beam pointing mechanism is excited again. The optical axis jitter generated at each resonant frequency point is obtained and sorted according to the magnitude of the optical axis jitter. Comparing the differences in optical axis jitter between the two instances, if the difference in optical axis jitter is greater than the set jitter threshold, the cause of the optical axis jitter is determined to be insufficient stability margin of the servo system; if the difference in optical axis jitter is less than or equal to the set jitter threshold, the cause of the optical axis jitter is determined to be that a certain optical element of the beam pointing mechanism has high elasticity, or that the entire platform has one or more large resonance peaks. Based on the determined cause of the optical axis jitter, the vibration error of the beam pointing mechanism is compensated. Repeat the above steps until the beam pointing performance meets the requirements under vibration conditions.

2. The method for vibration error distribution and suppression of an airborne suspended beam pointing mechanism according to claim 1, characterized in that: The shear frequency The determined condition is to ensure the operating frequency of the beam pointing mechanism. The open-loop frequency response amplitude at the point is greater than or equal to the output angle. With maximum error The ratio, i.e. Simultaneous cutoff frequency The phase margin at that point is between 40° and 60°.

3. The method for vibration error distribution and suppression of an airborne suspended beam pointing mechanism according to claim 2, characterized in that: The jitter in the two directions of the optical axis in the image is respectively , The recording duration should be at least 1 minute; the total optical axis jitter... The formula is as follows: In the formula, i represents the number of samples taken within the recording time, and n represents the total number of samples taken within the recording time; Set the error threshold as ,when At that time, the requirements were met.

4. The method for vibration error distribution and suppression of an airborne suspended beam pointing mechanism according to claim 3, characterized in that: The frequency point where resonance occurs is recorded as follows: The amplification factor corresponding to the resonant point is recorded as follows: .

5. The method for vibration error distribution and suppression of an airborne suspended beam pointing mechanism according to claim 4, characterized in that: When the beam pointing mechanism is excited by constant frequency vibration, in the non-open-loop state, the optical axis jitter generated at each resonant frequency point is: In the open-loop state, the optical axis jitter generated at each resonant frequency point is: The differences between the two optical axis jitter values ​​are respectively .

6. The method for vibration error distribution and suppression of an airborne suspended beam pointing mechanism according to claim 5, characterized in that: The jitter threshold is: .

7. The method for vibration error distribution and suppression of an airborne suspended beam pointing mechanism according to claim 6, characterized in that: The method for compensating for the vibration error of the beam pointing mechanism is as follows: When the cause of optical axis jitter is determined to be insufficient stability margin of the servo system, compensation is made by adjusting the control parameters. If the cause of the optical axis jitter is determined to be that a certain optical element of the beam pointing mechanism has high elasticity, compensation is made by reinforcing the optical element to increase its rigidity. When the cause of optical axis jitter is determined to be one or more large resonance peaks in the entire platform, compensation is made by increasing damping or vibration absorbers to weaken the resonance peaks. The above three measures can be implemented individually or in combination.

8. The method for vibration error distribution and suppression of an airborne suspended beam pointing mechanism according to claim 7, characterized in that: When compensation is performed by adjusting control parameters, a differential correction network is used. ,in, Represents the time constant; Represents the Laplace operator; Indicates the adjustment factor; adjustment coefficient This reduces the value from 1 to an appropriate level, increasing the stability margin of the servo system.

9. The method for vibration error distribution and suppression of an airborne suspended beam pointing mechanism according to claim 8, characterized in that: The vibration absorber consists of a spring, a damper, and a mass block. Adjusting the spring and the mass block can adjust the resonant frequency and amplification until the optical axis jitter of the beam pointing mechanism at the resonant point is attenuated to less than the error threshold.

10. A vibration error distribution and suppression system for an airborne suspended beam pointing mechanism, used to implement the vibration error distribution and suppression method for an airborne suspended beam pointing mechanism as described in any one of claims 1-9, characterized in that: Includes a beam pointing mechanism, an excitation module, a stability margin adjustment module, and a vibration absorber; By applying wideband or fixed-frequency vibration to the beam pointing mechanism through the excitation module, the frequency points where resonance occurs and the corresponding magnification of the resonance points are recorded, and the amount of optical axis jitter generated at each frequency point where resonance occurs is obtained. The control parameters are adjusted by the stability margin adjustment module to compensate for insufficient stability margin. The resonance peak is weakened by a vibration absorber, thus compensating for the large resonance peak.

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