Magnetic torquer magnetic current driving real-time compensation method and system

Abstract

The invention discloses a magnetic torquer magnetic current driving real-time compensation method, which comprises the following steps: firstly, carrying out voltage reverse acquisition on a magnetic current driving circuit, calibrating the precision of acquired resistance and voltage, then recording the magnitude of a magnetic current instruction and an actual magnetic current within a period of time, and carrying out linear fitting through least square to obtain a magnetic current driving real-time compensation result; and a magnetic current compensation coefficient is calculated, and real-time correction of the magnetic current driven by the magnetic current is realized. According to the method, the actual magnetic current driven by the magnetic torquer can be calculated and compensated on orbit in real time, high-precision control over the magnetic current is achieved, the precision of the output torque of the magnetic torquer is improved, and a better foundation is provided for satellite high-precision attitude control.

Description

Technical Field

[0001] This invention relates to the field of satellite magnetic torquer control, and more specifically to a method and system for real-time compensation of magnetic torquer magnetic current drive. Background Technology

[0002] Magnetic torquers are commonly used actuators for attitude control in satellites. By applying a certain magnetic current to the magnetic torquer, the magnetic torquer generates a magnetic moment, which interacts with the Earth's magnetic field to produce a magnetic torque that acts on the satellite, thereby achieving attitude control of the satellite.

[0003] Currently, there are two main control methods for magnetic torquers: voltage control and pulse width modulation (PWM). A magnetic torquer typically consists of a coil and a magnetic rod with high permeability, low remanence, and low loss. Due to the inductive load of the coil, PWM suffers from output delay, leading to poor control accuracy. However, with the maturation of component performance, the use of analog circuits to generate voltage control to produce a constant current magnetic drive for the magnetic torquer is increasingly being applied in satellite magnetic torquer control.

[0004] Typical magnetic torque circuits employ voltage control, such as... Figure 1 As shown, the attitude and orbit control computer generates a control voltage according to the control law, which in turn drives a transistor and a power resistor to generate a magnetic current of a corresponding magnitude, which is then applied to the magnetic torque device.

[0005] However, due to certain deviations in the performance of analog circuit components and the dead-zone problem in analog circuit driving, there is a certain deviation between the actual generated magnetic current and the magnetic current required by the control law. At the same time, the magnetic current deviation is also caused by the influence of ambient temperature during the analog circuit driving process, resulting in errors in the output torque of the magnetic torquer, which in turn affects the performance of high-precision satellite control. Summary of the Invention

[0006] The technical problem solved by this invention is to address the shortcomings of existing technologies by providing a real-time compensation method and system for magnetic torquer magnetic current drive, thereby achieving correction of the generated actual magnetic current.

[0007] The technical solution adopted in this invention is: a real-time compensation method for magnetic torquer magnetic current drive, comprising: S1. Set up a reverse sampling voltage channel to detect the voltage across the power resistor on the power resistor driven by the magnetic torque voltage control, and measure the resistance impedance R corresponding to the magnetic current reverse sampling voltage channel. S2. Calibrate the accuracy of the voltage acquisition channel of the attitude and orbit control computer; S3, the magnetic torque drive magnetic current for compensation output; S4. Record the magnetic torquer magnetic current command and the corresponding actual magnetic current in real time on track; S5. Calibrate and fit the recorded magnetic torquer magnetic current command with the actual magnetic current. S6. Update the magnetic current compensation coefficient; S7. Clear the recorded magnetic torquer magnetic current command and actual magnetic current, and repeat S4~S6.

[0008] Furthermore, the accuracy of the voltage acquisition channel of the calibration attitude control computer includes: A reference voltage is provided by a regulated power supply to calibrate the voltage U acquired by the attitude and orbit control computer. in With actual voltage U out Relationship: , in, and All of these are calibration coefficients.

[0009] Furthermore, the magnetic torque drive magnetic current for compensation output includes: The magnetic current I is obtained according to the control law zhiling The command performs compensation to obtain the compensated magnetic current I. buchang : , in, and This is the magnetic current compensation coefficient; The compensated magnetic current I buchang It is converted into a magnetic torque converter control voltage, which drives the magnetic torque converter circuit to generate a corresponding magnetic current.

[0010] Furthermore, the on-orbit real-time recording of the magnetic torquer's magnetic current command and corresponding actual magnetic current includes: The range of the magnetic current driving the magnetic torquer is divided into N intervals, and in each interval... i Record a magnetic current I zhiling_i Command and corresponding actual magnetic current I shiji_i ;i=1,2,3,…,N;N is a positive integer.

[0011] Furthermore, the step of calibrating and fitting the recorded magnetic torquer magnetic current command with the actual magnetic current includes: Within a time period T set according to the orbital cycle, when the number of recorded magnetic torque current commands reaches m, where 3 ≤ m ≤ N, based on the recorded magnetic torque current... I zhiling_i Command and actual magnetic current I shiji_i By performing least-squares fitting, we obtain: , Among them, calibration coefficient Calibration coefficient .

[0012] Furthermore, in step S6, the calibration coefficients calculated in step S5 are used... k and b Update the magnetic current compensation coefficient in S3. and : when and Update when , ; Otherwise, do not update the magnetic current compensation coefficient. and ; in, and This is for updating the calibration threshold.

[0013] A real-time compensation system for magnetic torquer magnetic current drive based on the above method includes: The reverse sampling voltage channel is connected in parallel with the power resistor driven by the magnetic torque device voltage control, and is used to detect the voltage across the power resistor; The magnetic torquer drives the magnetic current for compensation output; The data acquisition module is used to record the magnetic current command and corresponding actual magnetic current of the magnetic torquer in real time on the track. The data processing module is used to calibrate and fit the recorded magnetic torquer magnetic current command with the actual magnetic current to obtain calibration coefficients k and b; and to update the magnetic current compensation coefficients according to the magnitude of calibration coefficients k and b.

[0014] The advantages of this invention compared to the prior art are: The method in this invention can calculate the actual magnetic current driven by the compensating magnetic torquer in real time on orbit, achieve high-precision control of the magnetic current, improve the accuracy of the output torque of the magnetic torquer, and provide a better foundation for high-precision attitude control of satellites. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the voltage drive circuit for the magnetic torquer. Figure 2 This is a flowchart of the compensation method of the present invention. Detailed Implementation

[0016] The present invention will be described in conjunction with the accompanying drawings and embodiments.

[0017] like Figure 2 As shown, a real-time compensation method for magnetic torquer driven by magnetic current is described, and the specific implementation steps are as follows: Step S1: Set up the magnetic current reverse sampling voltage channel and measure the corresponding sampling resistor impedance. A reverse sampling channel is provided on the power resistor driven by the magnetic torquer voltage control to detect the voltage across the power resistor. After the magnetic current drive control product is delivered, the resistance impedance R corresponding to the magnetic current reverse sampling voltage channel is measured.

[0018] Step S2: Accuracy of the voltage acquisition channel of the ground-based attitude and orbit control computer. The attitude and orbit control computer measures voltage via an AD acquisition channel. However, voltage measurements are subject to accuracy deviations. The ground provides an accurate reference voltage through a regulated power supply to calibrate the voltage U acquired by the attitude and orbit control computer. in With actual voltage U out The relationship between the two is as follows:

[0019] in, and For the actual voltage U out With the collected voltage U in The calibration coefficient.

[0020] Step S3: The magnetic torquer drives the magnetic current for compensation output. The magnetic current command I is obtained based on the control law. zhiling The compensated current I is obtained according to the following formula. buchang Then, the compensated magnetic current is converted into a magnetic torque control voltage, which drives the circuit to generate the corresponding magnetic current.

[0021]

[0022] in, and For compensation coefficient, The initial value is 1. The initial value is 0, and it is updated iteratively according to subsequent steps.

[0023] Step S4: Record the magnetic torquer's magnetic current command and corresponding actual magnetic current in real time on track. The range of the magnetic current driving the magnetic torquer is divided into N intervals. When the magnetic current of the magnetic torquer is within one of these intervals, the magnetic current I is recorded once. zhiling_i Commands (i=1,…N) and corresponding acquired voltages U in_i Based on the relationship in step S2, the actual voltage U is calculated. out_i Based on the resistance R corresponding to the reverse sampling voltage channel in step S1, the actual magnetic current I is calculated. shiji_i =U out_i / R.

[0024] Step S5: Calibrate and fit the recorded magnetic torquer magnetic current command with the actual magnetic current. Within a set time period T based on the orbital period, after the number of recorded magnetic current commands reaches m times (3≤m≤N), the recorded magnetic current command I is used... zhiling_i and actual magnetic current I shiji_i By performing least-squares fitting, the calibration relationship between the two is obtained as follows:

[0025] Among them, calibration coefficient Calibration coefficient .

[0026] Step S6: Update the magnetic current compensation coefficient Update the magnetic current compensation coefficients based on the calibration coefficients calculated in step S5. and :when and Update , Otherwise, the magnetic current compensation coefficient will not be updated this time. and The previous value remains unchanged. and The calibration thresholds are updated, with initial values ​​of 0.01 and 0.1, respectively.

[0027] Step S7: Clear the recorded magnetic torquer magnetic current command and corresponding actual magnetic current, and recalculate according to the steps. After completing step S6, clear the recorded magnetic torquer magnetic current command and corresponding actual magnetic current, and then recalculate and update the magnetic current compensation coefficient according to steps S4 to S6.

[0028] A real-time compensation system for magnetic torquer magnetic current drive based on the above method includes: The reverse sampling voltage channel is connected in parallel with the power resistor driven by the magnetic torque device voltage control, and is used to detect the voltage across the power resistor; The magnetic torquer drives the magnetic current for compensation output; The data acquisition module is used to record the magnetic current command and corresponding actual magnetic current of the magnetic torquer in real time on the track. The data processing module is used to calibrate and fit the recorded magnetic torquer magnetic current command with the actual magnetic current to obtain calibration coefficients k and b; and to update the magnetic current compensation coefficients according to the magnitude of calibration coefficients k and b.

[0029] Example: This invention provides a real-time compensation method for magnetic torquer driven by magnetic current. Taking a satellite in a sun-synchronous orbit at an altitude of 700 km, operating for a long period of time, as an example, the technical solution of this invention is further described, but the scope of protection is not limited to the described method.

[0030] The satellite is subject to environmental disturbance torques during long-term operation in orbit, causing a continuous increase in the angular momentum of its actuators, such as the flywheel. This necessitates continuous magnetic torque drive per orbit to magnetically unload the satellite's angular momentum. This satellite is equipped with a 50Am... 2 The magnetic torque generator has a maximum driving magnetic current of 100mA. The attitude and orbit control computer drives the magnetic current by generating a driving control voltage of 0V~10V.

[0031] The specific implementation steps of this invention are as follows: Step S1: Set up the magnetic current reverse sampling voltage channel and measure the corresponding sampling resistor impedance. A parallel sampling resistor is connected to the power resistor driven by the magnetic torque voltage control to provide a reverse sampling channel for detecting the voltage across the power resistor. After the magnetic current drive control product is delivered, the impedance R corresponding to the magnetic current reverse sampling voltage channel is measured to be 82Ω.

[0032] Step S2: Accuracy of the voltage acquisition channel of the ground-based attitude and orbit control computer. The attitude and orbit control computer measures voltage via an AD acquisition channel. However, voltage measurements are subject to accuracy deviations. The ground provides an accurate reference voltage through a regulated power supply to calibrate the voltage U acquired by the attitude and orbit control computer. in With actual voltage U out The relationship is shown in the following specific test data:

[0033] The relationship between the two obtained by fitting is as follows:

[0034] Step S3: The magnetic torquer drives the magnetic current for compensation output. The magnetic current command is obtained based on the control law. I zhiling The compensated current is obtained according to the following formula. I buchang The compensation circuit converts the voltage into a magnetic torque control voltage, which drives the circuit to generate a corresponding magnetic current.

[0035]

[0036] in, and For compensation coefficient, The initial value is 1. The initial value is 0, and it is updated iteratively according to subsequent steps.

[0037] Step S4: Record the magnetic torquer's magnetic current command and corresponding actual magnetic current in real time on track. In this example, the range of the magnetic torque drive current is 0mA~100mA. Based on this range, the magnetic torque drive current is divided into 20 intervals. A magnetic current command is recorded once when the magnetic torque current falls within one of these intervals. I zhiling_i (i=1,…20) and the corresponding collected voltages U in_i Based on the relationship in step S2, the actual voltage is calculated. U out_i Based on the resistance R corresponding to the reverse sampling voltage channel in step S1, the actual magnetic current is calculated. I shiji_i = U out_i / R.

[0038] The initial recorded magnetic current command and the actual magnetic current magnitude are as follows:

[0039] Step S5: Calibrate and fit the recorded magnetic torquer magnetic current command with the actual magnetic current. Within a time period T set according to the orbital period, when the number of recorded magnetic current commands is m=5 (3≤m≤20), the recorded magnetic current command I is... zhiling_i and actual magnetic current I shiji_i By performing least-squares fitting, the calibration relationship between the two is obtained as follows:

[0040] Step S6: Update the magnetic current compensation coefficient The calibration coefficients calculated in step S5 , Update the magnetic current compensation coefficient and : and Update the magnetic current compensation coefficient , .

[0041] Step S7: Clear the recorded magnetic torquer magnetic current command and corresponding actual magnetic current and recalculate. After completing step S6, clear the recorded magnetic torquer magnetic current command and corresponding actual magnetic current, and then recalculate and update the magnetic current compensation coefficient according to steps S4 to S6.

[0042] The magnetic current command and actual magnetic current magnitude recorded in step S4 are as follows:

[0043] Following step S5, the recorded magnetic torquer magnetic current command and the actual magnetic current are calibrated and fitted to obtain the following calibration relationship between the two:

[0044] Following step S6 again, the calibration coefficients calculated in the previous step are... , ,satisfy and Conditions for updating the magnetic current compensation coefficient. , .

[0045] Follow step S7 again to clear the recorded magnetic torquer magnetic current command and corresponding actual magnetic current, then follow steps S4-S6 to recalculate and update the magnetic current compensation coefficient. If the calibration coefficient calculated in step S5 does not meet the conditions: and Afterwards, the magnetic current compensation coefficient is not updated in this cycle, as it meets the set accuracy requirements. Subsequent on-orbit real-time calculation of the calibration coefficient in step S5 can monitor the impact of external environmental factors such as temperature on the magnetic torquer drive circuit, enabling the magnetic current compensation coefficient to be updated again, thus improving the accuracy of the magnetic torquer's magnetic current in real time.

[0046] Although the present invention has been described in detail through the foregoing examples, it should be understood that the above description should not be considered as a limitation of the invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the foregoing. Therefore, the scope of protection of the present invention should be defined by the appended claims.

[0047] The parts of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A magnetic momenter magnetic current drive real-time compensation method, characterized in that, The method comprises the following steps: S1, setting a back sampling voltage channel for detecting the voltage across the power resistor on the power resistor of the magnetic torque controller voltage control drive, and measuring the resistance impedance R corresponding to the back sampling voltage channel of the magnetic current; S2, calibrating the precision of the voltage acquisition channel of the attitude and orbit control computer; S3, compensating and outputting the magnetic current of the magnetic torque controller; S4, recording the magnetic current command and the corresponding actual magnetic current of the magnetic torque controller in real time in orbit; S5, calibrating and fitting the recorded magnetic current command and the actual magnetic current of the magnetic torque controller; S6, updating the magnetic current compensation coefficient; S7, clearing the recorded magnetic current command and the actual magnetic current of the magnetic torque controller, and repeating S4-S6.

2. The magnetic momenter magnetic current drive real-time compensation method according to claim 1, characterized in that: The method for calibrating the precision of the voltage acquisition channel of the attitude and orbit control computer comprises the following steps: The reference voltage is provided by a regulated power supply, and the voltage U collected by the attitude and orbit control computer is calibrated in The relationship between the actual voltage U out ​ ， wherein and are calibration coefficients.

3. The magnetic momenter magnetic current drive real-time compensation method according to claim 2, characterized in that: The method for compensating and outputting the magnetic current of the magnetic torque controller comprises the following steps: The magnetic current I zhiling The instruction is compensated to obtain the compensated magnetic current I buchang : ， wherein and is a magnetic current compensation factor; The compensated magnetic current I buchang is converted into a magnetic torque generator control voltage, which drives the magnetic torque generator circuit to generate a corresponding magnetic current.

4. The magnetic momenter magnetic current drive real-time compensation method according to claim 3, characterized in that: The method for recording the magnetic current command and the corresponding actual magnetic current of the magnetic torque controller in real time in orbit comprises the following steps: The range of the magnetic torque driver driving the magnetic current is divided into N intervals, and in each interval i Record the magnetic current once I zhiling_i Instructions and corresponding actual magnetic current I shiji_i ; i = 1, 2, 3, …, N; N is a positive integer.

5. The magnetic momenter magnetic current drive real-time compensation method according to claim 4, characterized in that: The method for calibrating and fitting the recorded magnetic current command and the actual magnetic current of the magnetic torque controller comprises the following steps: According to the track period, a time period T is set, and when the number of recorded magnetic torque motor magnetic current instructions reaches m times, 3≤m≤N, according to the recorded magnetic torque motor magnetic current I zhiling_i Instructions and actual magnetic current I shiji_i , the least square fitting is carried out, and the following is obtained: ， wherein the calibration coefficient , the calibration coefficient .

6. The magnetic momenter magnetic current drive real-time compensation method according to claim 5, characterized in that: In the S6, the magnetic current compensation coefficient in the S3 is updated according to the calibration coefficient calculated in the S5 k and b and :​ When and then update , ; Otherwise, the magnetic current compensation coefficient is not updated and ; wherein and are updateable calibration thresholds.

7. A magnetic momenter magnetic current drive real-time compensation system, characterized in that, The method comprises the following steps: The back sampling voltage channel is connected in parallel on the power resistor of the magnetic torque controller voltage control drive, and is used for detecting the voltage across the power resistor; The magnetic current of the magnetic torque controller is compensated and outputted; The data acquisition module is used for recording the magnetic current command and the corresponding actual magnetic current of the magnetic torque controller in real time in orbit; The data processing module is used for calibrating and fitting the recorded magnetic current command and the actual magnetic current of the magnetic torque controller, obtaining the calibration coefficients k and b, and updating the magnetic current compensation coefficient according to the size of the calibration coefficients k and b.

8. A magnetic momenter magnetic current drive real-time compensation system according to claim 7, characterized in that: The method for compensating and outputting the magnetic current of the magnetic torque controller comprises the following steps: The magnetic current I zhiling The instruction is compensated to obtain the compensated magnetic current I buchang : ， wherein and is a compensation factor; The compensated magnetic current I buchang is converted into a magnetic torque generator control voltage, which drives the magnetic torque generator circuit to generate a corresponding magnetic current.

9. A magnetic momenter magnetic current drive real-time compensation system according to claim 8, characterized in that: The method for recording the magnetic current command and the corresponding actual magnetic current of the magnetic torque controller in real time in orbit comprises the following steps: The range of the magnetic torque driver driving the magnetic current is divided into N intervals, and in each interval i Record the magnetic current once I zhiling_i Instructions and corresponding actual magnetic current I shiji_i ; i=1, 2, 3, …, N; N is a positive integer.

10. A magnetic torque-wrench magnetic current drive real-time compensation system according to claim 9, characterized in that: The method for calibrating and fitting the recorded magnetic current command and the actual magnetic current of the magnetic torque controller comprises the following steps: According to the track period, a time period T is set, and when the number of recorded magnetic torque motor magnetic current instructions reaches m times, 3≤m≤N, according to the recorded magnetic torque motor magnetic current I zhiling_i Instructions and actual magnetic current I shiji_i , the least square fitting is carried out, and the following is obtained: ， wherein the calibration coefficient , the calibration coefficient ; When and , update , ; Otherwise, the magnetic current compensation coefficient is not updated and ; wherein and are updatable calibration thresholds.

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