An adaptive control method and system for effective set of an ultrasonic motor aperture

Abstract

The application discloses an effective set adaptive control method and system for an ultrasonic motor diaphragm, and belongs to the technical field of optical precision control. The method realizes automatic tracking of dynamic changes of a system through online estimation and real-time update of pseudo partial derivatives, realizes adaptive compensation of positive and reverse friction asymmetry through introduction of a motion direction flag signal, enhances robustness in an extreme thermal environment through an adaptive mechanism of a temperature change rate, converts solving of control input into a quadratic programming problem with physical constraints and solves the problem through an effective set method, and reduces resource consumption on a star while improving the precision and reliability of diaphragm aperture control.

Description

Technical Field

[0001] This invention relates to the field of optical precision control technology, specifically to an adaptive control method and system for the effective set of ultrasonic motor apertures, which is particularly suitable for the precise control of camera apertures in aerospace optical systems such as low-orbit satellite remote sensing imaging, star sensor optical calibration, and space target monitoring. Background Technology

[0002] Ultrasonic motors utilize the inverse piezoelectric effect of piezoelectric ceramics to generate high-frequency micro-vibrations and output macroscopic motion through the friction between the stator and the mover. They have advantages such as fast response, high positioning accuracy, self-locking upon power failure, and no electromagnetic interference. They are widely used to drive variable apertures, and have significant application prospects, especially in resource-constrained aerospace optical systems.

[0003] Variable apertures adjust the amount of light transmitted by changing the aperture size, and are a key component for achieving continuous variable F-number in optical systems. When low-Earth orbit satellites are in orbit, their optical payloads face extreme temperature fluctuations ranging from -100℃ to +100℃. At the same time, they are limited by onboard power consumption, weight, and assembly space, which places extremely stringent requirements on the environmental adaptability, resource efficiency, and long-term reliability of the aperture drive system.

[0004] However, as low-orbit satellite ultrasonic motor-driven aperture systems move towards high-precision applications, they face the following coupled technical challenges: (1) The extreme temperature alternation from -100℃ to +100℃ causes the ultrasonic motor's resonant frequency to drift continuously and its friction characteristics to change drastically; (2) The vacuum environment causes convective heat dissipation to fail, exacerbating the motor's temperature rise and coupling with the low-temperature alternation; (3) The frictional force between the aperture blades changes significantly with temperature, direction, and vacuum environment, exhibiting strong nonlinearity; (4) Onboard resources are severely limited, making it impossible to install high-precision temperature or displacement sensors; (5) There is a nonlinear geometric mapping relationship between the active ring rotation angle and the aperture. The coupling characteristics unique to the space environment cause the compensation strategy calibrated on the ground to fail rapidly after orbit.

[0005] Therefore, there is a need for an adaptive aperture control method that does not rely on precise mathematical models, does not require additional dedicated temperature sensors, and has a computational complexity suitable for spaceborne implementation. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides an ultrasonic motor aperture control scheme that features strong anti-interference capabilities, high precision, and eliminates the need for an additional dedicated temperature sensor.

[0007] To achieve the above objectives, the present invention provides an adaptive control method for the effective set of an ultrasonic motor aperture, comprising:

[0008] S1: Establish the input-output data model of the ultrasonic motor-driven aperture system for low-Earth orbit satellites, using the ultrasonic motor driving frequency as the control input. The system output is determined by the rotation angle or aperture of the aperture movement ring. ;

[0009] S2: At each sampling time An equivalent linear data model is established using the compact form dynamic linearization technique:

[0010] ;

[0011] in, It is a pseudo-partial derivative. and These are the changes in system output and control input, respectively; the pseudo-partial derivatives Updated online at each sampling time based on the latest input and output data;

[0012] S3: Introduce motion direction indicator signals Two sets of pseudo-partial derivative estimates are maintained for the opening and closing directions of the aperture, respectively. and The pseudo-partial derivatives corresponding to the current direction of motion are estimated online using the following method. :

[0013] ;

[0014] in, Step size factor As a weighting factor; This is the increment of the driving frequency from the previous moment; This is the pseudo-partial derivative estimate stored in the previous time step, corresponding to the current direction of motion; This represents the change in system output at the current moment.

[0015] S4: Obtain the current temperature using existing onboard temperature telemetry data or actuator temperature monitoring values. Calculate the rate of temperature change ,in The sampling period is The temperature at the previous moment; adaptively adjust the control weighting factor. ,in As the benchmark control weighting factor, This is the temperature adaptive coefficient;

[0016] S5: Construct a quadratic programming optimization problem with control input constraints, and find the optimal control input so that the system output tracks the desired trajectory. The criterion function is as follows:

[0017] ;

[0018] The constraints are as follows:

[0019] ;

[0020] in The expected output; The current temperature adaptive control weighting factor. The frequency of the ultrasonic motor drive at the previous sampling time. This represents the physical lower limit of the ultrasonic motor drive frequency. This represents the physical upper limit of the ultrasonic motor drive frequency;

[0021] S6: Solve the quadratic programming problem using the effective set method to obtain the optimal control increment. ;

[0022] S7: Control quantity It is applied to the ultrasonic motor.

[0023] Optionally, the pseudo-partial derivative estimation in step S3 further includes a reset mechanism: when or or At that time, Reset to initial value ,in It is a very small positive number, and its value is [value]. .

[0024] Optionally, the temperature information in step S4 The acquisition method is as follows: using existing temperature telemetry data on the satellite or the temperature monitoring function of the ultrasonic motor driver itself, the current temperature value is estimated using a linear extrapolation method between two temperature telemetry data updates. ,in This refers to the most recent update time of temperature telemetry data. for Temperature value at time, for The rate of temperature change at any given time; in the calculation of the rate of temperature change, a sliding window averaging method is used to smooth temperature measurement noise, and the window width is taken as... One sampling point.

[0025] Optionally, the specific steps for solving the quadratic programming problem using the effective set method described in S6 include:

[0026] Calculate the unconstrained optimal solution ;

[0027] judge Does the constraint condition meet?

[0028] If the constraints are satisfied, then If the limit is exceeded, then If it is below the lower limit, then .

[0029] Optionally, the rotation angle of the aperture movable ring With aperture The mapping relationship between them was obtained through ground calibration experiments: ,in, The geometric mapping function for the aperture mechanism is determined by the aperture blade shape and installation parameters; when the control target is the aperture diameter, the desired rotation angle is... pass Calculate, where, The desired aperture is given; the drift in the mapping relationship caused by temperature changes after on-orbit operation is automatically compensated by online updates of the pseudo-partial derivatives.

[0030] Optionally, the system output y(k) is acquired by a spaceborne image sensor or photoelectric encoder.

[0031] On the other hand, the present invention also provides an adaptive control system for the effective set of an ultrasonic motor aperture, comprising: an ultrasonic motor, which is a traveling wave type rotating ultrasonic motor, and whose speed is controlled by adjusting the driving frequency; a variable aperture, including an aperture fixed coil, an aperture moving coil and multiple aperture blades; a drive and control unit, including a drive circuit and a spaceborne digital controller, for executing the adaptive control method for the effective set of an ultrasonic motor aperture as described in any of the above technical solutions; and a feedback acquisition unit, which uses a spaceborne image sensor or photoelectric encoder to acquire aperture diameter or moving ring rotation angle information.

[0032] The advantages of this invention compared to existing technologies are as follows: This invention requires no precise model and can adapt to the unknown space environment solely based on input and output data. Through online estimation of pseudo-partial derivatives, it automatically tracks the resonance drift and frictional changes caused by temperature alternation from -100℃ to +100℃, without requiring a dedicated temperature sensor, utilizing only existing onboard telemetry. It is the first to compensate for asymmetric friction between forward and reverse apertures without a model framework, demonstrating significant effectiveness across a wide vacuum temperature range. A temperature change rate feedforward is superimposed on pseudo-partial derivative feedback, forming a dual-resistant temperature shock architecture. The algorithm contains only four arithmetic operations, completed in microseconds per step, adaptable to onboard FPGA / DSP, requiring no high-performance chips; it employs an effective set method to explicitly handle driving frequency constraints, ensuring safety. It has fewer parameters, is easy to debug, and significantly shortens the ground calibration cycle. Simultaneously, it can cope with complex disturbances such as frictional drift and irradiation degradation throughout its entire lifespan, exhibiting strong robustness. Attached Figure Description

[0033] Figure 1 This is a flowchart of the adaptive control method for the effective set of ultrasonic motor apertures provided by the present invention;

[0034] Figure 2 This is a comparison diagram of the speed tracking of the AS-MFAC controller and the PID controller provided by this invention under step response;

[0035] Figure 3 This is a tracking error curve of the AS-MFAC controller provided by the present invention under periodic load changes;

[0036] Figure 4 This is a comparison chart of the tracking performance of the AS-MFAC controller provided by this invention at different desired speeds;

[0037] Figure 5 This is a structural diagram of the adaptive control device for the effective set of ultrasonic motor apertures provided by the present invention. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] Reference Figure 1 This embodiment provides an adaptive control method for the effective set of an ultrasonic motor aperture, comprising the following steps:

[0040] S1: Establish the input-output data model of the ultrasonic motor-driven aperture system for low-Earth orbit satellites, using the ultrasonic motor driving frequency as the control input. The system output is determined by the rotation angle or aperture of the aperture movement ring. .

[0041] S2: At each sampling time An equivalent linear data model is established using the compact format dynamic linearization technique.

[0042] Specifically, for general discrete-time nonlinear systems:

[0043] ;

[0044] in, For an unknown nonlinear function, Let be the lag order of the output quantity in the nonlinear function. This represents the lag order of the input quantity in the nonlinear function.

[0045] According to CFDL theory, when a system satisfies certain Lipschitz conditions, there exists a time-varying parameter—the pseudo-partial derivative. This allows the system to be equivalently represented by the following linear data model:

[0046] ;

[0047] in:

[0048] ;

[0049] ;

[0050] Regarding the satisfaction of the Lipschitz condition: For the ultrasonic motor-driven aperture system involved in this invention, the change in system output (aperture angle or aperture) caused by a finite change in the control input (drive frequency) within any finite time interval is bounded. Specifically, the operating frequency range of the ultrasonic motor is typically 40 kHz to 45 kHz, and the mechanical travel range of the aperture is finite. Within any finite time interval, the finite change in the drive frequency... Corresponding output changes satisfy Lipschitz constant It can be estimated through ground calibration experiments. Even under extreme temperature alternation conditions of -100℃ to +100℃, the rate of change of the system output is still bounded, so the CFDL modeling conditions are always satisfied over a wide temperature range.

[0051] The linear data model provided in this embodiment allows the system to use a [data model] near each operating point. This is equivalently described by a linear time-varying model of coefficients, thus completely bypassing the difficult problem of establishing a globally accurate mathematical model. Because... Based on the latest input and output data, the system is updated online at each sampling moment. It can automatically track dynamic changes caused by factors such as extreme temperature changes in space, vacuum environment, and on-orbit aging, and achieve adaptive suppression of time-varying interference.

[0052] It should be noted that, in this embodiment, due to the pseudo-partial derivatives... It is unknown and time-varying, requiring online estimation using system input and output data. The following criterion function is designed:

[0053] ;

[0054] in, The pseudo-partial derivative at the current moment, This is the pseudo-partial derivative of the previous time step. This is the weighting factor.

[0055] By finding the extrema of the criterion function, we obtain the estimation law for the pseudo-partial derivative:

[0056] ;

[0057] in, This is the step size factor, which controls the convergence speed of the estimation. This is used as a weighting factor to prevent the denominator from being zero.

[0058] S3: Introduce motion direction indicator signals Two sets of pseudo-partial derivative estimates are maintained for the opening and closing directions of the aperture, respectively. and The pseudo-partial derivatives corresponding to the current direction of motion are estimated online using the following method. :

[0059] ;

[0060] in, Step size factor As a weighting factor; This is the increment of the driving frequency from the previous moment; The data stored from the previous moment, corresponding to the current direction of motion. The pseudo-partial derivative estimate; This represents the change in the system output at the current moment.

[0061] When the direction of motion changes, the controller automatically calls the pseudo-partial derivative estimate of the corresponding direction to participate in the control law calculation, thereby effectively compensating for the impact of forward and reverse friction asymmetry on control accuracy.

[0062] In other embodiments, to ensure the robustness of the algorithm under extreme temperature alternation conditions in space, a reset mechanism is introduced: the pseudo-partial derivatives are reset to their initial values ​​when the following conditions occur. :

[0063] ;

[0064] in, It is a very small positive number (typically taking the value of ). This reset mechanism ensures that the algorithm remains stable even when system parameters change drastically due to extreme temperature variations from -100℃ to +100℃, making it a key design feature for ensuring the long-term reliable operation of the spaceborne optical aperture in orbit.

[0065] S4: Obtain the current temperature using existing onboard temperature telemetry data or actuator temperature monitoring values. Calculate the rate of temperature change ,in The sampling period is The temperature value at the previous sampling time; adaptive adjustment of the control weight factor. ,in As the benchmark control weighting factor, This is the temperature adaptive coefficient.

[0066] It should be noted that the temperature information T(k) in this invention is obtained by using existing temperature telemetry data on the satellite (such as temperature monitoring values ​​provided by the satellite platform thermal control subsystem) or by using the existing temperature monitoring function of the ultrasonic motor driver itself (such as temperature sensing elements in the drive circuit), without adding a dedicated temperature sensor.

[0067] It should also be noted that the update frequency of on-board temperature telemetry data is typically 1 Hz to 10 Hz, lower than the control sampling frequency (1 kHz) of this invention. To address this issue, this invention employs a linear extrapolation method to estimate the current temperature value between two temperature telemetry data updates:

[0068] ;

[0069] in, This refers to the most recent update time of the temperature telemetry data. The most recent temperature change rate measurement is used. In the temperature change rate calculation, a sliding window averaging method (window width of 5-10 sampling points) is employed to smooth temperature measurement noise. Simulation experiments show that even with a temperature telemetry data update frequency of only 1 Hz, the temperature adaptive mechanism of this invention still works effectively, and the control performance is significantly improved compared to the non-temperature adaptive scheme.

[0070] Furthermore, it should be noted that regarding temperature extrapolation error, at the instant the satellite enters or exits the Earth's shadow (the moment when the rate of temperature change changes drastically), the linear extrapolated value may deviate from the actual temperature. To address this issue, this invention employs the following error compensation mechanism: (a) upon detecting the rate of temperature change... The change exceeds a preset threshold (e.g.) When a sudden temperature change is detected, the extrapolation mode is immediately switched to hold mode. (a) Under normal operating conditions, the cumulative time of extrapolation error does not exceed the interval between two temperature telemetry updates (maximum 1 second), and the thermal time constant of the ultrasonic motor system is usually on the order of several seconds to tens of seconds, which is much larger than the temperature telemetry update interval. Therefore, the impact of extrapolation error on the control system is within an acceptable range; (b) The online update mechanism of pseudo-partial derivatives itself has the ability to adapt to model errors and can compensate for the impact of temperature extrapolation error to a certain extent.

[0071] Control weighting factor Adaptive adjustment based on the rate of temperature change:

[0072] ;

[0073] in, As the benchmark control weighting factor, This is the temperature adaptive coefficient.

[0074] In this embodiment, the temperature adaptive coefficient The systematic tuning process is as follows:

[0075] First, under normal temperature conditions, fix Determined through step response experiments The optimal value is determined by the overshoot. And the adjustment time is the shortest.

[0076] Secondly, tests were conducted under extreme temperature conditions (-80℃ and +80℃). Tracking performance at values ​​of 0.005, 0.01, 0.02, 0.03, 0.05, and 0.08.

[0077] Then, calculate each Comprehensive performance indicators across the entire temperature range under the given values:

[0078] ;

[0079] in, For temperature Maximum tracking error under, The standard deviation of the tracking error at each temperature point. These are the weighting coefficients.

[0080] Finally, choose to make smallest The value is used as the final setpoint. Typically, for the aperture system described in this invention, The optimal value is between 0.015 and 0.03.

[0081] It should be noted that when the temperature changes drastically, the control weight factor automatically increases to limit the drastic changes in the control quantity and prevent system instability caused by temperature shocks; when the temperature tends to stabilize, the control weight factor returns to the reference value to ensure tracking accuracy.

[0082] S5: Construct a quadratic programming optimization problem with control input constraints, and find the optimal control input so that the system output tracks the desired trajectory. The criterion function is as follows:

[0083] ;

[0084] The constraints are as follows:

[0085] ;

[0086] in The expected output; The current temperature adaptive control weighting factor. The frequency of the ultrasonic motor drive at the previous sampling time. This represents the physical lower limit of the ultrasonic motor drive frequency. This represents the physical upper limit of the ultrasonic motor drive frequency.

[0087] S6: Solve the quadratic programming problem using the effective set method to obtain the optimal control increment. .

[0088] Specifically, first, assuming no constraints, we solve for the unconstrained optimal solution. :

[0089] make ,have to:

[0090]

[0091] Solving for:

[0092] ;

[0093] Secondly, check Does the constraint condition meet?

[0094] Next, if the constraints are met, then directly adopt... As the optimal solution; if Then the constraint will be Considered a valid constraint, ;like Then the constraint will be Considered a valid constraint, ;

[0095] S7: Control quantity It is applied to the ultrasonic motor.

[0096] It should also be noted that, in this embodiment, the aperture diameter... With the corner of the moving ring The nonlinear relationship between them can be expressed as:

[0097] ;

[0098] in, The geometric mapping function of the aperture mechanism is determined by the shape of the aperture blades and installation parameters. Discrete data points of this mapping relationship can be obtained through ground calibration experiments, and its numerical relationship can be established using interpolation or fitting methods. This mapping relationship may undergo slight changes under alternating space temperatures, but because this invention employs a data-driven online adaptive mechanism, such changes are automatically absorbed by the real-time updates of the pseudo-partial derivatives, eliminating the need for recalibration.

[0099] Therefore, the control objective of the system can be equivalently expressed as: controlling the driving frequency of the ultrasonic motor. To make the moving ring rotate at an angle Tracking expected turning angle Thus achieving the desired aperture .

[0100] Reference Figure 2 , Figure 2 This is a comparison graph of the speed tracking of the AS-MFAC controller (Active Set-based Model-Free Adaptive Control, AS-MFAC, based on a tight-form dynamic linearization model and effective set selection, i.e., the effective set adaptive control of the ultrasonic motor aperture provided in this embodiment) and the PID controller under step response. The horizontal axis represents time, and the vertical axis represents speed, showing the differences in overshoot and settling time between the two controllers. The step response experiment was set to a desired speed increase from 0 r / min to 100 r / min, with a sampling period of 1 ms, and the control algorithm parameters being step size factors. Weighting factors Benchmark control weighting factor Temperature adaptive coefficient .from Figure 2 It can be seen that the overshoot of AS-MFAC is about 1 / 6 of that of PID, the response speed is about 3.7 times that of PID, and the speed fluctuation is significantly lower than that of PID control, indicating that AS-MFAC performs significantly better than PID control in step response.

[0101] Reference Figure 3 , Figure 3 This is a tracking error curve of the AS-MFAC controller provided by the invention under periodic load changes. The horizontal axis represents time, and the vertical axis represents tracking error, showing the dynamic response characteristics of the controller under periodic disturbances. The simulation duration was set for 10 complete orbital cycles (approximately 15 hours). Wide temperature range and The procedure was carried out under a vacuum environment. Figure 3 It can be seen that under periodic load variations, the maximum tracking error of the AS-MFAC controller is only 5.43%; across the entire wide temperature range, AS-MFAC keeps the tracking error within a certain range. Within (maximum error only) ,exist The improvement rate was 75.9% compared to traditional PID control, indicating that the method has good adaptability to the characteristics of ultrasonic motor systems with drastic temperature changes.

[0102] Reference Figure 4 , Figure 4This is a comparison chart of the tracking performance of the AS-MFAC controller provided by this invention at different desired speeds; the horizontal axis represents the desired speed, and the vertical axis represents the actual speed, showing the tracking accuracy of the controller at different set values. During the simulation, periodic load disturbances were applied to the output shaft of the ultrasonic motor to simulate the change in friction between the aperture blades in a vacuum environment. Figure 4 It can be seen that the AS-MFAC controller can achieve accurate tracking under different desired speed setpoints, and the actual speed has good linear consistency with the desired speed. This indicates that the method can maintain stable control performance across the entire speed range, has good setpoint tracking capability, and is suitable for the precise control requirements of the aperture at different aperture positions.

[0103] Reference Figure 5 This embodiment also provides an adaptive control system for the effective set of an ultrasonic motor aperture, comprising: an ultrasonic motor, which is a traveling wave type rotating ultrasonic motor, and whose speed is controlled by adjusting the driving frequency; a variable aperture, including an aperture fixed coil, an aperture moving coil and multiple aperture blades; a drive and control unit, including a drive circuit and a spaceborne digital controller, for executing the adaptive control method for the effective set of an ultrasonic motor aperture described in any of the above embodiments; and a feedback acquisition unit, which uses a spaceborne image sensor or photoelectric encoder to acquire aperture diameter or moving ring rotation angle information.

[0104] In addition, embodiments of the present invention also provide a computer-readable storage medium, wherein the computer-readable storage medium may store a program that, when executed, includes some or all of the steps of any ultrasonic motor aperture effective set adaptive control method described in the above method embodiments.

[0105] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0106] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0107] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage device, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0108] An exemplary flowchart for implementing an adaptive control method for the effective set of ultrasonic motor apertures according to an embodiment of the present invention has been described above with reference to the accompanying drawings. It should be noted that the numerous details included in the above description are merely illustrative of the invention and not intended to limit it. In other embodiments of the invention, the method may have more, fewer, or different steps, and the order, inclusion, function, and other relationships between the steps may differ from those described and illustrated.

Claims

1. An adaptive control method for the effective set of an ultrasonic motor aperture, characterized in that, include: S1: Establish the input-output data model of the ultrasonic motor-driven aperture system for low-Earth orbit satellites, using the ultrasonic motor driving frequency as the control input. The system output is determined by the rotation angle or aperture of the aperture movement ring. ; S2: At each sampling time An equivalent linear data model is established using the compact form dynamic linearization technique: ； in, It is a pseudo-partial derivative. and These are the changes in system output and control input, respectively; the pseudo-partial derivatives Updated online at each sampling time based on the latest input and output data; S3: Introduce motion direction indicator signals Two sets of pseudo-partial derivative estimates are maintained for the opening and closing directions of the aperture, respectively. and The pseudo-partial derivatives corresponding to the current direction of motion are estimated online using the following method. : ； in, Step size factor As a weighting factor; This is the increment of the driving frequency from the previous moment; This is the pseudo-partial derivative estimate stored in the previous time step, corresponding to the current direction of motion; This represents the change in system output at the current moment. S4: Obtain the current temperature using existing onboard temperature telemetry data or actuator temperature monitoring values. Calculate the rate of temperature change ,in The sampling period is The temperature at the previous moment; adaptively adjust the control weighting factor. ,in As the benchmark control weighting factor, This is the temperature adaptive coefficient; S5: Construct a quadratic programming optimization problem with control input constraints, and find the optimal control input so that the system output tracks the desired trajectory. The criterion function is as follows: ； The constraints are as follows: ； in The expected output; The current temperature adaptive control weighting factor. The frequency of the ultrasonic motor drive at the previous sampling time. This represents the physical lower limit of the ultrasonic motor drive frequency. This represents the physical upper limit of the ultrasonic motor drive frequency; S6: Solve the quadratic programming problem using the effective set method to obtain the optimal control increment. ; S7: Control quantity It is applied to the ultrasonic motor.

2. The adaptive control method for the effective set of ultrasonic motor apertures according to claim 1, characterized in that, The pseudo-partial derivative estimation in step S3 also includes a reset mechanism: when or or At that time, Reset to initial value ,in It is a very small positive number, and its value is [value]. .

3. The adaptive control method for the effective set of ultrasonic motor apertures according to claim 1, characterized in that, The temperature information in step S4 The acquisition method is as follows: using existing temperature telemetry data on the satellite or the temperature monitoring function of the ultrasonic motor driver itself, the current temperature value is estimated using a linear extrapolation method between two temperature telemetry data updates. ,in This refers to the most recent update time of temperature telemetry data. for Temperature value at time, for The rate of temperature change at any given time; in the calculation of the rate of temperature change, a sliding window averaging method is used to smooth temperature measurement noise, and the window width is taken as... One sampling point.

4. The adaptive control method for the effective set of ultrasonic motor apertures according to claim 1, characterized in that, The specific steps for solving quadratic programming problems using the effective set method described in S6 include: Calculate the unconstrained optimal solution ; judge Does the constraint condition meet? If the constraints are satisfied, then If the limit is exceeded, then If it is below the lower limit, then .

5. The adaptive control method for the effective set of ultrasonic motor apertures according to claim 1, characterized in that, The aperture movable rotation angle With aperture The mapping relationship between them was obtained through ground calibration experiments: ,in, The geometric mapping function for the aperture mechanism is determined by the aperture blade shape and installation parameters; when the control target is the aperture diameter, the desired rotation angle is... pass Calculate, where, The desired aperture is given; the drift in the mapping relationship caused by temperature changes after on-orbit operation is automatically compensated by online updates of the pseudo-partial derivatives.

6. The adaptive control method for the effective set of ultrasonic motor apertures according to claim 1, characterized in that, The system output y(k) is acquired by a spaceborne image sensor or photoelectric encoder.

7. An adaptive control system for an effective collection of ultrasonic motor apertures, characterized in that, include: The ultrasonic motor is a traveling wave type rotary ultrasonic motor, and the speed is controlled by adjusting the drive frequency. The variable aperture includes a fixed aperture ring, a moving aperture ring, and multiple aperture blades; The drive and control unit, including a drive circuit and a spaceborne digital controller, is used to execute the adaptive control method for the effective set of ultrasonic motor apertures as described in any one of claims 1 to 6. The feedback acquisition unit uses a spaceborne image sensor or photoelectric encoder to acquire information on the aperture or the rotation angle of the movable ring.

8. A computer-readable storage medium, comprising a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the adaptive control method for the effective set of ultrasonic motor apertures as described in any one of claims 1 to 6.

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