Satellite-borne magnetic moment adjuster

Abstract

The application relates to a satellite-borne magnetic moment adjuster which is digitized and adjusts a magnetic moment value, and comprises a magnetic component control unit, a temperature sensor and a three-axis magnetic moment adjuster; the temperature sensor and the three-axis magnetic moment adjuster are electrically connected with the magnetic component control unit respectively; the magnetic component control unit is also electrically connected with a satellite-borne computer, and receives a target magnetic moment instruction control signal from the satellite-borne computer; the magnetic component control unit generates a driving signal for controlling the size and direction of the current in each magnetic moment coil according to the target magnetic moment instruction control signal; and the temperature value measured by the temperature sensor and the magnetic moment feedback value of each magnetic moment coil are collected in real time; through temperature compensation and magnetic moment control, the magnetic moment value corresponding to the target magnetic moment instruction control signal is generated in each magnetic moment coil, and the attitude of the satellite is adjusted. The application can make the satellite attitude adjustment more accurate and more stable, and save the workload of the satellite-borne computer.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of satellites, and particularly relates to a satellite-borne magnetic moment adjuster for digital adjustment of a magnetic moment value. BACKGROUND

[0002] The tri-axial fluxgate magnetometer is a magnetic measurement sensitive component of a satellite attitude control subsystem for measuring the magnetic induction intensity vector of the geomagnetic field in orbit, and is used to determine the tri-axial attitude of the satellite, and assist the satellite attitude algorithm to ensure that the magnetic moment adjuster generates correct control moments. The magnetic moment adjuster is an important execution component of the satellite attitude control system, and through the application of control currents in the tri-axial magnetic moment coils, interacts with the geomagnetic field to generate desired control moments on the satellite body, and can realize functions such as flywheel unloading, satellite attitude control, and preliminary attitude acquisition.

[0003] The traditional switch-type analog magnetic assembly and the integrated electronic system share 8 QQL control level signals. The integrated electronic system controls the forward and reverse switches of the magnetic moment adjuster through the 8 QQL control level signals, and the 8 control signals are divided into 4 switch signals and 4 direction signals. The corresponding logical relationship between the computer control and the magnetic moment is shown in Table 1. The advantage of this control method is that it is mature in technology and simple in control method, but the disadvantage is that it can only control the magnetic moment adjuster to output a positive or negative magnetic moment, and cannot control the magnetic moment adjuster to output an adjustable magnetic moment value.

[0004] Table 1 Control signal interface example

[0005] SUMMARY

[0006] In view of the above analysis, the application aims to disclose a satellite-borne magnetic moment adjuster for digital adjustment of a magnetic moment value, which is used to output an adjustable magnetic moment value of the satellite-borne magnetic moment adjuster, and ultimately achieve the purpose of accurate satellite attitude control.

[0007] The application discloses a satellite-borne magnetic moment adjuster for digital adjustment of a magnetic moment value, which comprises a magnetic assembly control unit, a temperature sensor and a tri-axial magnetic moment adjuster; the tri-axial magnetic moment adjuster comprises three magnetic moment coils of x, y and z axes; the temperature sensor and the three magnetic moment coils are electrically connected with the magnetic assembly control unit respectively;

[0008] The magnetic assembly control unit is also electrically connected with a satellite-borne computer, and receives a target magnetic moment instruction control signal from the satellite-borne computer;

[0009] The magnetic assembly control unit generates a driving signal for controlling the size and direction of the current in each magnetic moment coil according to the target magnetic moment instruction control signal; and collects the temperature value measured by the temperature sensor and the magnetic moment feedback value of each magnetic moment coil in real time; through temperature compensation and magnetic moment control, a target magnetic moment value corresponding to the target magnetic moment instruction control signal is generated in each magnetic moment coil, and the attitude of the satellite is adjusted.

[0010] Further, the magnetic assembly control unit comprises a controller, a driving circuit, a bleeding circuit and a current collection circuit.

[0011] The driving circuit is connected between the controller and each magnetic moment coil, and is used for performing D / A conversion and power amplification on a digital driving control signal output by the controller circuit, and then outputting the signal to the corresponding magnetic moment coil, so that the magnetic moment coil outputs a magnetic moment.

[0012] The bleeding circuit is connected between the driving power supply of the driving circuit and each magnetic moment coil, and is used for dissipating the stored electrical energy in the magnetic moment coil when the driving is turned off.

[0013] The current collection circuit is connected between the controller and each magnetic moment coil, and is used for collecting the real-time current value of the corresponding magnetic moment coil, and obtaining a coil current digital signal through signal amplification and A / D conversion, and then outputting the signal to the controller.

[0014] The controller is used for converting the received target magnetic moment instruction control signal into a magnetic moment target value digital signal for controlling each magnetic moment coil respectively, converting the coil current digital signal received from each magnetic moment coil into a magnetic moment actual value digital signal, and performing temperature compensation and magnetic moment control according to the magnetic moment target value digital signal and the magnetic moment actual value digital signal and the current temperature value, and outputting a magnetic moment control value digital signal for controlling each magnetic moment coil.

[0015] Further, the driving circuit connected between the controller and each magnetic moment coil comprises a digital-to-analog converter, a driver and a driving amplifier.

[0016] The digital-to-analog converter is used for performing D / A conversion on the magnetic moment control value digital signal output by the controller circuit to obtain a magnetic moment analog value control signal, and then outputting the signal to the driver.

[0017] The driver is used for isolating and amplifying the analog value control signal and then outputting the signal to the driving amplifier.

[0018] The driving amplifier is used for performing power amplification on the magnetic moment analog value control signal.

[0019] The driving amplifier comprises an operational amplifier U1, resistors R1-R4, an NPN transistor Q1, a PNP transistor Q2, and diodes D1 and D2.

[0020] The inverting input terminal of the operational amplifier U1 is connected to the output terminal of the magnetic torque sensor, the non-inverting input terminal is connected to the analog ground through resistor R1, and the output terminal is connected to the gate of the NPN transistor Q1 through resistor R2 and to the base of the PNP transistor Q2 through resistor R3.

[0021] The emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q2 are connected together and connected to the coil A of the magnetic torque sensor.

[0022] The anode of the diode D1 is connected to the collector of the NPN transistor Q1, and the cathode is connected to the emitter of the NPN transistor Q1.

[0023] The anode of the diode D2 is connected to the collector of the PNP transistor Q2, and the cathode is connected to the emitter of the PNP transistor Q2.

[0024] Resistor R4 is connected between the emitter of the NPN transistor Q1 and the inverting input terminal of the operational amplifier U1.

[0025] Further, the discharge circuit connected between the driving power supply of the driving circuit and each magnetic torque coil comprises a first discharge circuit and a second discharge circuit.

[0026] The first discharge circuit is connected between the collector of the NPN transistor Q1 and the positive driving power supply, and the coil A of the magnetic torque coil is connected to the first discharge circuit through the anode and cathode of the diode D1.

[0027] The second discharge circuit is connected between the collector of the PNP transistor Q2 and the negative driving power supply.

[0028] The coil B of the magnetic torque coil is connected to the second discharge circuit through the cathode and anode of the diode D2.

[0029] If the magnetic torque coil outputs a positive magnetic torque when the driving is turned off, the voltage at the coil A of the magnetic torque coil is higher than that at the coil B due to the stored electrical energy in the magnetic torque coil. Since the coil B is connected to the reference ground, the positive voltage at the coil A makes the diode D1 conductive, and the stored electrical energy in the magnetic torque coil is discharged through the first discharge circuit.

[0030] If the magnetic torque coil outputs a negative magnetic torque when the driving is turned off, the voltage at the coil A of the magnetic torque coil is lower than that at the coil B due to the stored electrical energy in the magnetic torque coil. Since the coil B is connected to the reference ground, the negative voltage at the coil A makes the diode D2 conductive, and the stored electrical energy in the magnetic torque coil is discharged through the second discharge circuit.

[0031] Further, the PNP transistor Q3, the NPN transistors Q4, Q5, the diodes D3, D4, the resistors R5-R10;

[0032] The diodes D3, D4 are connected in parallel, and the NPN transistors Q4, Q5 are connected in parallel; the anode of the parallel diodes is connected to the positive pole of the driving power supply, and the cathode of the parallel diodes is connected to the collector of the PNP transistor Q3; the base of the PNP transistor Q3 is connected to the positive pole of the driving power supply through the resistor R5, and the emitter is connected to the analog ground through the resistor R6;

[0033] The base of the NPN transistor Q4 is connected to the emitter of the PNP transistor Q3 through the resistor R7, the collector is connected to the cathode of the parallel diodes through the resistor R8, and the emitter is connected to the analog ground through the resistor R9;

[0034] The base of the NPN transistor Q5 is connected to the emitter of the PNP transistor Q3 through the resistor R7, the collector is connected to the cathode of the parallel diodes through the resistor R8, and the emitter is connected to the analog ground through the resistor R10;

[0035] The cathode of the parallel diodes is connected to the collector of the NPN transistor Q1. Further, the second discharge circuit comprises: the NPN transistors Q6-Q8, the diodes D5, D6, and the resistors R11-R16;

[0036] The diodes D5, D6 are connected in parallel, and the NPN transistors Q7, Q8 are connected in parallel; the negative pole of the driving power supply is connected to the cathode of the parallel diodes, and the anode of the parallel diodes is connected to the emitter of the NPN transistor Q6 through the resistor R12; the base of the NPN transistor Q6 is connected to the negative pole of the driving power supply through the resistor R11, and the collector is connected to the analog ground;

[0037] The base of the NPN transistor Q7 is connected to the emitter of the NPN transistor Q6 through the resistor R13, the collector is connected to the analog ground through the resistor R14, and the emitter is connected to the anode of the parallel diodes through the resistor R15;

[0038] The base of the NPN transistor Q8 is connected to the emitter of the NPN transistor Q6 through the resistor R13, the collector is connected to the analog ground through the resistor R14, and the emitter is connected to the anode of the parallel diodes through the resistor R16;

[0039] The anode of the parallel diodes is connected to the collector of the NPN transistor Q2.

[0040] Further, a sampling resistor R16 is connected in series in a power supply loop of the magnetic moment coil, the current collection circuit collects a voltage value of the sampling resistor R16, after filtering, amplification and isolation amplification, the coil current sampling value is obtained through an A / D conversion circuit.

[0041] Further, the current collection circuit comprises a first filter, a voltage amplifier, a second filter, an isolator and an A / D converter connected in sequence.

[0042] The first filter is an RC filter, which filters the voltage value collected from the resistor R16.

[0043] The voltage amplifier is a reverse proportional amplifier, which amplifies the filtered voltage signal.

[0044] The second filter is a two-stage RC filter connected in series, which filters the amplified voltage signal.

[0045] The isolator is a photoelectric isolator, which is connected between the second filter and the A / D converter.

[0046] The A / D converter is used for A / D conversion of the isolated voltage signal to output a digital signal of the collected current.

[0047] Further, the resistance value of the three magnetic moment coils of the three-axis magnetic moment device is measured by a thermostat to obtain a function of the resistance value of the magnetic moment coil changing with temperature, which is stored in the magnetic assembly control unit.

[0048] Further, in the temperature compensation, the current flowing through the magnetic moment coil at different temperatures is controlled to be constant, so that the magnetic moment generated in the magnetic moment coil is kept constant.

[0049] The present application can achieve at least one of the following beneficial effects:

[0050] The present application adopts full digitalization, realizes continuous adjustable output magnetic moment of the satellite-borne magnetic moment device and high-precision acquisition of the magnetic moment device signal, controls force rejection output to be continuous, so that the satellite attitude adjustment precision is higher and the attitude adjustment is more stable, and the workload of the satellite-borne computer is saved. BRIEF DESCRIPTION OF DRAWINGS

[0051] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not considered as limiting the present application, and the same reference signs represent the same components throughout the drawings.

[0052] Figure 1 The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not considered as limiting the present application, and the same reference signs represent the same components throughout the drawings.

[0053] Figure 2The schematic diagram of the controller related interface in the embodiment of the present application is shown in the figure;

[0054] Figure 3 The schematic diagram of the D / A converter circuit in the embodiment of the present application is shown in the figure;

[0055] Figure 4 The schematic diagram of the emitter and drive amplifier circuit in the embodiment of the present application is shown in the figure;

[0056] Figure 5 The schematic diagram of the first bleeder circuit in the embodiment of the present application is shown in the figure;

[0057] Figure 6 The schematic diagram of the second bleeder circuit in the embodiment of the present application is shown in the figure;

[0058] Figure 7 The schematic diagram of the current collection circuit in the embodiment of the present application is shown in the figure;

[0059] Figure 8 The schematic diagram of the A / D converter circuit in the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0060] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings, which form a part of this application, and together with the embodiments of the present application serve to explain the principles of the present application.

[0061] One embodiment of the present application discloses a satellite-borne magnetic moment adjuster, as shown in the figure, which comprises a magnetic assembly control unit, a temperature sensor and a three-axis magnetic moment adjuster. Figure 1 The three-axis magnetic moment adjuster comprises three magnetic moment coils (also referred to as magnetic moment coils) of x, y and z axes.

[0062] The temperature sensor is used to measure the temperature value of the three-axis magnetic moment adjuster.

[0063] The three magnetic moment coils are used to generate a magnetic moment to adjust the satellite attitude.

[0064] The temperature sensor and the three magnetic moment coils are electrically connected with the magnetic assembly control unit respectively.

[0065] The magnetic assembly control unit is also electrically connected with a satellite-borne computer and receives a target magnetic moment instruction control signal from the satellite-borne computer.

[0066] The magnetic assembly control unit generates a drive signal to control the current size and direction in each magnetic moment coil according to the target magnetic moment instruction control signal, and collects the temperature value measured by the temperature sensor and the magnetic moment feedback value of each magnetic moment coil in real time; through temperature compensation and magnetic moment control, the target magnetic moment value corresponding to the target magnetic moment instruction control signal is generated in each magnetic moment coil, so as to adjust the attitude of the satellite.

[0067] Specifically, the magnetic component control unit includes a controller, a drive circuit, a discharge circuit, a current acquisition circuit, and a power supply circuit;

[0068] A drive circuit is connected between the controller and each magnetic torque coil; the drive circuit is used to perform D / A conversion and power amplification on the digital drive control signal output by the controller circuit and output it to the corresponding magnetic torque coil so that the magnetic torque coil outputs magnetic torque.

[0069] A discharge circuit is connected between the drive power supply of the drive circuit and each magnetic torque coil; the discharge circuit is used to consume the electrical energy stored in the magnetic torque coil when the drive is turned off.

[0070] A current acquisition circuit is connected between the controller and each magnetic torque coil; the current acquisition circuit is used to acquire the real-time current value of the corresponding magnetic torque coil, and after signal amplification and A / D conversion, obtain the coil current digital signal, which is then output to the controller.

[0071] The controller is configured to convert the received target magnetic moment command control signal into a digital signal of the target magnetic moment value that controls each magnetic moment coil respectively, convert the digital signal of the coil current received from each magnetic moment coil into a digital signal of the actual magnetic moment value, perform temperature compensation and magnetic moment control based on the digital signal of the target magnetic moment value, the digital signal of the actual magnetic moment value, and the current temperature value, and output a digital signal of the magnetic moment control value that controls each magnetic moment coil.

[0072] The power supply circuit primarily converts the onboard power supply into various power sources required by the internal circuitry. The power supply component transforms the +27V power supplied onboard into +5V and ±12V power supplies to meet the power supply isolation requirements of the controller.

[0073] Specific working principle:

[0074] First, the onboard power supply transforms the +27V power provided by the satellite into +5V and ±12V power through the power circuit to meet the power isolation requirements of the controller's internal power supply. The power chip on the main control circuit board then performs a secondary transformation to provide the 3.3V and 1.9V power required for the operation of the DSP chip in the magnetic component control unit. After the DSP chip powers on normally, it first performs parameter initialization and system initialization, including DSP core initialization, interrupt register initialization, interrupt vector table initialization, system clock initialization, and peripheral initialization. Peripheral initialization includes IO initialization, SPI initialization, CANA bus initialization, CANB bus initialization, AD chip initialization, and DA chip initialization. Then, it waits for CAN bus commands. The controller reads the target magnetic moment command control signal input from the CAN bus (e.g., the input target magnetic moment value is 8Am) through the CAN communication module.2 ),

[0075] When the main control circuit board receives the target magnetic moment command control signal from the host computer, the controller on the main control circuit board collects the current flowing through the magnetic rod at the current moment as current feedback, and completes the conversion calculation between the current value and the magnetic moment value (for example, the collected actual magnetic moment value is 7.8 Am). 2 During data acquisition, an amplifier circuit and an AD chip are used to achieve high-precision signal acquisition.

[0076] Then, the magnetic moment values ​​corresponding to the two signals are compared and calculated. At the same time, the controller reads the current temperature value of the temperature sensor, calculates the resistance value of the three magnetic moment coils through the temperature compensation algorithm, and finally generates the drive control signal using the magnetic moment control algorithm.

[0077] The magnitude and direction of the current in the magnetic torquer coil are controlled and the power is driven. The drive uses the AD5764R DA chip output and amplification circuit to realize the output of the magnetic torque, ultimately achieving the purpose of making the magnetic torquer output a precise and adjustable magnetic torque.

[0078] For the controller-related interfaces of the magnetic components, see [link / reference]. Figure 2 This mainly includes: a CAN bus interface with the integrated electronic unit; an XINQF interface with the AD chip; an SPI interface with the DA chip; and an SPI interface with the temperature sensor. The DSP uses a parallel port to transmit data with the AD chip, completing the acquisition of magnetic moment information, including the output magnetic moment of the X-axis magnetic rod (-10Am). 2 ~10 Am 2 The output magnetic moment of the Y-axis magnetic rod (-10 Am) 2 ~10 Am 2 The output magnetic moment of the Z-axis magnetic rod (-10 Am) 2 ~10 Am 2 The DSP controls the DA chip to output the required voltage signal, thereby controlling the magnetic torque generator to output the corresponding magnetic torque. The magnetic torque output range is -10Am. 2 ~10 Am 2 .

[0079] Specifically, the drive circuit connecting the controller to each magnetic torque coil includes: a digital-to-analog converter, an emitter follower, and a drive amplifier;

[0080] The digital-to-analog converter is used to perform D / A conversion on the digital signal of magnetic moment control value output by the controller circuit to obtain the analog signal of magnetic moment control value, and output it to the emitter follower;

[0081] The emitter follower is used to isolate and amplify the analog control signal before outputting it to the driver amplifier;

[0082] The drive amplifier is used to amplify the power of the magnetic moment analog value control signal;

[0083] The driving amplifier includes operational amplifier U1, resistors R1-R4, NPN transistor Q1, PNP transistor Q2, and diodes D1 and D2;

[0084] The inverting input terminal of the operational amplifier U1 is connected to the output terminal of the emitter follower, the non-inverting input terminal is connected to analog ground via resistor R1, and the output terminal is connected to the gate of NPN transistor Q1 via resistor R2 and to the base of NPN transistor Q2 via resistor R3.

[0085] The emitters of NPN transistor Q1 and PNP transistor Q2 are connected together and then connected to terminal A of the magnetic torquer coil.

[0086] The anode of diode D1 is connected to the collector of NPN transistor Q1, and the cathode is connected to the emitter of NPN transistor Q1.

[0087] The anode of diode D2 is connected to the collector of PNP transistor Q2, and the cathode is connected to the emitter of PNP transistor Q2.

[0088] Resistor R4 is connected between the emitter of NPN transistor Q1 and the inverting input of operational amplifier U1.

[0089] Among them, the digital-to-analog converter circuit is as follows Figure 3 As shown, the emitter follower and drive amplifier are as follows Figure 4 As shown.

[0090] When the output positive magnetic moment of the control magnetic torquer is controlled, the positive voltage output by the operational amplifier U1 is amplified by the NPN transistor Q1 and outputs a positive voltage to the magnetic torque coil of the magnetic torquer, generating a positive magnetic moment of the corresponding magnitude;

[0091] When the output of the magnetic torque generator is controlled to be negative, the negative voltage output by the operational amplifier U1 is amplified by the PNP transistor Q2 and output to the magnetic torque coil of the magnetic torque generator, generating a negative magnetic torque of the corresponding magnitude.

[0092] Specifically, the discharge circuit connecting the drive power supply of the drive circuit to each magnetic torque coil includes a first discharge circuit and a second discharge circuit.

[0093] The first discharge circuit is connected between the collector of the NPN transistor Q1 and the positive power supply for the drive, and the A end of the magnetic torque coil is connected to the first discharge circuit through the anode and cathode of the diode D1.

[0094] The second discharge circuit is connected between the collector of the PNP transistor Q2 and the negative power supply for the drive.

[0095] The B end of the magnetic torque coil is connected to the second discharge circuit through the cathode and anode of diode D2;

[0096] If the drive is turned off when the magnetic torque coil is outputting magnetic torque in the positive direction, the electrical energy stored in the magnetic torque coil will make the voltage at terminal A of the magnetic torque coil higher than the voltage at terminal B; if terminal B is connected to the reference ground, the positive voltage at terminal A of the coil will turn on the diode D1, and the electrical energy stored in the magnetic torque coil will be discharged through the first discharge circuit.

[0097] If the drive is turned off when the magnetic torque coil is outputting magnetic torque in the negative direction, the electrical energy stored in the magnetic torque coil will cause the voltage at terminal A of the magnetic torque coil to be lower than the voltage at terminal B. If terminal B is connected to the reference ground, the negative voltage at terminal A of the coil will cause diode D2 to conduct, and the electrical energy stored in the magnetic torque coil will be discharged through the second discharge circuit.

[0098] like Figure 5 As shown, the first discharge circuit includes: PNP transistor Q3, NPN transistors Q4 and Q5, diodes D3 and D4, and resistors R5-R10;

[0099] The diodes D3 and D4 are connected in parallel, and the NPN transistors Q4 and Q5 are connected in parallel. The positive terminal of the drive power supply is connected to the anode of the parallel diodes, and the cathode of the parallel diodes is connected to the collector of the PNP transistor Q3. The base of the PNP transistor Q3 is connected to the positive terminal of the drive power supply through resistor R5, and the emitter is connected to the analog ground through resistor R6.

[0100] The base of NPN transistor Q4 is connected to the emitter of PNP transistor Q3 through resistor R7, the collector is connected to the cathode of a parallel diode through resistor R8, and the emitter is connected to analog ground through resistor R9.

[0101] The base of NPN transistor Q5 is connected to the emitter of PNP transistor Q3 through resistor R7, the collector is connected to the cathode of a parallel diode through resistor R8, and the emitter is connected to analog ground through resistor R10.

[0102] The cathode of the parallel diode is connected to the collector of the NPN transistor Q1;

[0103] The resistor R8 is a resistor network consisting of multiple resistors connected in parallel.

[0104] Transistors Q3, Q4, and Q5 are power transistors. Under normal operation, power transistors Q3, Q4, and Q5 are not conducting. When feedback energy occurs, the feedback voltage turns on Q3, which in turn turns on power transistors Q4 and Q5, dissipating the energy across the resistor.

[0105] like Figure 6As shown, the second discharge circuit includes: NPN transistors Q6-Q8, diodes D5 and D6, and resistors R11-R16;

[0106] The diodes D5 and D6 are connected in parallel, and the NPN transistors Q7 and Q8 are connected in parallel. The negative terminal of the driving power supply is connected to the cathode of the parallel diodes, and the anode of the parallel diodes is connected to the emitter of the NPN transistor Q6 through resistor R12. The base of the NPN transistor Q6 is connected to the negative terminal of the driving power supply through resistor R11, and the collector is connected to analog ground.

[0107] The base of NPN transistor Q7 is connected to the emitter of NPN transistor Q6 through resistor R13, the collector is connected to analog ground through resistor R14, and the emitter is connected to the anode of a parallel diode through resistor R15.

[0108] The base of NPN transistor Q8 is connected to the emitter of NPN transistor Q6 through resistor R13, the collector is connected to analog ground through resistor R14, and the emitter is connected to the anode of a parallel diode through resistor R16.

[0109] The anode of the parallel diode is connected to the collector of the NPN transistor Q2;

[0110] The resistor R14 is a resistor network consisting of multiple resistors connected in parallel.

[0111] Transistors Q6-Q8 are power transistors. Under normal operation, transistors Q6-Q8 are not conducting. When feedback energy occurs, the feedback voltage turns Q6 on, which in turn turns on power transistors Q7 and Q8, dissipating the energy in the resistor.

[0112] A sampling resistor R16 is connected in series in the power supply circuit of the magnetic torquer coil. The current acquisition circuit acquires the voltage value of the sampling resistor R16. After filtering, amplification and isolation amplification, the coil current sampling value is obtained through the A / D conversion circuit.

[0113] The sampling resistor R16 is a small resistor, preferably 2.5 ohms, which can be achieved by connecting multiple resistors in parallel.

[0114] Specifically, the current acquisition circuit is used to acquire the voltage value across the sampling resistor R16 connected in series with the magnetic torque coil. The voltage signal is amplified 21 times by the voltage acquisition circuit and then acquired by the high-precision AD7656 chip.

[0115] The current acquisition circuit includes a first filter, a voltage amplifier, a second filter, an isolator, and an A / D converter connected in sequence.

[0116] The first filter is an RC filter that filters the voltage value collected from resistor R16;

[0117] The voltage amplifier is an inverting proportional amplifier that amplifies the filtered voltage signal.

[0118] The second filter is a two-stage cascaded RC filter that filters the amplified voltage signal;

[0119] The isolator is an emitter follower, connected between the second filter and the A / D converter;

[0120] The A / D converter is used to convert the isolated voltage signal into a digital signal of the acquired current.

[0121] Specifically, the current acquisition circuit is as follows: Figure 7 As shown. Figure 8 This is a circuit diagram of an A / D converter.

[0122] Specifically, the resistance values ​​of the three magnetic torque coils of the triaxial magnetic torque generator are measured with temperature using a constant temperature chamber to obtain the function of the magnetic torque coil resistance value changing with temperature, which is then stored in the magnetic component control unit.

[0123] Test method: Place the magnetic torquer coil in a constant temperature chamber and connect the external circuit. Set the temperature of the constant temperature chamber to a fixed value. After the temperature in the constant temperature chamber stabilizes, read the current through the magnetic torquer coil and the terminal voltage of the magnetic torquer. Change the temperature of the constant temperature chamber and repeat the above experiment.

[0124] The resistance value of the magnetic torquer was obtained by testing and the characteristics of the resistance value increasing with temperature were obtained. The test data of temperature and resistance value were fitted and the resistance value R of the magnetic torquer coil was fitted into a linear equation of the resistance (Q0, R0) at the set temperature value.

[0125] Specifically, in this embodiment, in temperature compensation, the magnetic moment generated in the magnetic torque coil is kept constant by controlling the current flowing through the magnetic torque coil at different temperatures.

[0126] At a set temperature Q0, directly applying pressure to the magnetic torquer to V0 yields a magnetic moment output of 10Am. 2 At that time, the resistance R of the three magnetic torque coils was measured. i0 , i = x, y, z.

[0127] During temperature compensation, the magnetic moment output is kept constant at 10Am. 2 At this time, the current flowing through the magnetic torque coil must be kept constant; that is, the voltage applied to the magnetic torque device must be kept constant. .

[0128] The current temperature is collected, and the resistance value R of the magnetic torquer coil corresponding to the current temperature value is obtained according to the linear equation of temperature compensation. i This allows us to obtain the voltage value V that needs to be applied to the magnetic torque device.

[0129] In the magnetic moment control of the controller, based on the target magnetic moment value in the target magnetic moment command control signal, the voltage value that needs to be applied to the magnetic torque coil at the current temperature is calculated; based on the collected current magnetic torque coil current value I... i Based on the current temperature of the magnetic torque coil resistance R i Calculate the actual voltage value of the magnetic torquer coil at the current temperature, compare the voltages, and then control the magnitude of the drive signal for the magnetic torquer coil so that the actual voltage value of the magnetic torquer coil at the current temperature is the same as the voltage value to be applied to the magnetic torquer coil, so that the magnetic moment output by the magnetic torquer coil reaches the target magnetic moment.

[0130] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A space-borne magnetic moment adjuster for digitizing a magnetic moment value, characterized by, The magnetic assembly control unit, the temperature sensor and the three-axis magnetic torque device are connected with each other; the three-axis magnetic torque device comprises three magnetic torque coils of x, y and z axes; the temperature sensor and the three magnetic torque coils are respectively connected with the magnetic assembly control unit; The magnetic assembly control unit is also connected with the satellite computer, and receives a target magnetic moment instruction control signal from the satellite computer; The magnetic assembly control unit generates a drive signal for controlling the size and direction of the current in each magnetic torque coil according to the target magnetic moment instruction control signal; The temperature value measured by the temperature sensor and the magnetic moment feedback value of each magnetic torque coil are collected in real time; through temperature compensation and magnetic moment control, the target magnetic moment value corresponding to the target magnetic moment instruction control signal is generated in each magnetic torque coil, so as to adjust the attitude of the satellite; The magnetic assembly control unit comprises a controller, a drive circuit, a discharge circuit and a current collection circuit; The drive circuit connected between the controller and each magnetic torque coil comprises a digital-to-analog converter, a shunt regulator and a drive amplifier; The digital-to-analog converter is used for performing D / A conversion on the magnetic moment control value digital signal output by the controller circuit to obtain a magnetic moment analog value control signal, and outputting the magnetic moment analog value control signal to the shunt regulator; The shunt regulator is used for isolating and amplifying the analog value control signal and outputting the analog value control signal to the drive amplifier; The drive amplifier is used for power amplifying the magnetic moment analog value control signal; The drive amplifier comprises an operational amplifier U1, resistors R1-R4, an NPN transistor Q1, a PNP transistor Q2 and diodes D1 and D2; The inverting input end of the operational amplifier U1 is connected with the output end of the shunt regulator, the non-inverting input end is connected with the analog ground through the resistor R1, and the output end is respectively connected with the gate of the NPN transistor Q1 through the resistor R2 and connected with the base of the PNP transistor Q2 through the resistor R3; The emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q2 are connected together and connected with the coil A of the magnetic torque device; The anode of the diode D1 is connected with the collector of the NPN transistor Q1, and the cathode is connected with the emitter of the NPN transistor Q1; The anode of the diode D2 is connected with the collector of the PNP transistor Q2, and the cathode is connected with the emitter of the PNP transistor Q2; The resistor R4 is connected between the emitter of the NPN transistor Q1 and the inverting input end of the operational amplifier U1.

2. The satellite-borne magnetic torque device according to claim 1, wherein A drive circuit is connected between the controller and each magnetic torque coil; the drive circuit is used for performing D / A conversion and power amplification on the digital drive control signal output by the controller circuit and outputting the digital drive control signal to the corresponding magnetic torque coil, so that the magnetic torque coil outputs a magnetic moment; A discharge circuit is connected between the drive power supply of the drive circuit and each magnetic torque coil; the discharge circuit is used for dissipating the stored electric energy in the magnetic torque coil when the drive is turned off; A current collection circuit is connected between the controller and each magnetic torque coil; The current collection circuit is used for collecting the real-time current value of the corresponding magnetic torque coil, performing signal amplification and A / D conversion on the real-time current value to obtain a coil current digital signal, and outputting the coil current digital signal to the controller. The controller is used for converting the received target magnetic moment instruction control signal into a magnetic moment target value digital signal for controlling each magnetic moment coil, converting the received coil current digital signal from each magnetic moment coil into a magnetic moment actual value digital signal, and performing temperature compensation and magnetic moment control according to the magnetic moment target value digital signal and the magnetic moment actual value digital signal and the current temperature value, and outputting a magnetic moment control value digital signal for controlling each magnetic moment coil.

3. The space-borne magnetic momenter of claim 1, wherein, The discharge circuit connected between the driving power supply of the driving circuit and each magnetic moment coil comprises a first discharge circuit and a second discharge circuit; The first discharge circuit is connected between the collector of the NPN transistor Q1 and the positive driving power supply, and the magnetic moment coil A end is connected with the first discharge circuit through the anode and cathode of the diode D1. The second discharge circuit is connected between the collector of the PNP transistor Q2 and the negative driving power supply, and the magnetic moment coil B end is connected with the second discharge circuit through the cathode and anode of the diode D2. If the magnetic moment coil outputs a positive magnetic moment when the driving is turned off, the voltage at the A end of the magnetic moment coil is higher than that at the B end due to the stored electric energy in the magnetic moment coil; the positive voltage at the A end of the coil makes the diode D1 conductive when the B end is connected with the reference ground, and the stored electric energy in the magnetic moment coil is discharged through the first discharge circuit. If the magnetic moment coil outputs a negative magnetic moment when the driving is turned off, the voltage at the A end of the magnetic moment coil is lower than that at the B end due to the stored electric energy in the magnetic moment coil; the negative voltage at the A end of the coil makes the diode D2 conductive when the B end is connected with the reference ground, and the stored electric energy in the magnetic moment coil is discharged through the second discharge circuit. The first discharge circuit comprises a PNP transistor Q3, NPN transistors Q4 and Q5, diodes D3 and D4, and resistors R5-R10.

4. The space-borne magnetic momenter of claim 3, wherein, The diodes D3 and D4 are connected in parallel, and the NPN transistors Q4 and Q5 are connected in parallel; the positive electrode of the positive driving power supply is connected with the anode of the parallel diodes, and the cathode of the parallel diodes is connected with the collector of the PNP transistor Q3; the base of the PNP transistor Q3 is connected with the positive electrode of the positive driving power supply through the resistor R5, and the emitter is connected with the analog ground through the resistor R6; The base of the NPN transistor Q4 is connected with the emitter of the PNP transistor Q3 through the resistor R7, the collector is connected with the cathode of the parallel diodes through the resistor R8, and the emitter is connected with the analog ground through the resistor R9; The base of the NPN transistor Q5 is connected with the emitter of the PNP transistor Q3 through the resistor R7, the collector is connected with the cathode of the parallel diodes through the resistor R8, and the emitter is connected with the analog ground through the resistor R10; The cathode of the parallel diodes is connected with the collector of the NPN transistor Q1. The second discharge circuit comprises NPN transistors Q6-Q8, diodes D5 and D6, and resistors R11-R16.

5. The space-borne magnetic momenter of claim 3, wherein, ​ The diodes D5 and D6 are connected in parallel, and the NPN triodes Q7 and Q8 are connected in parallel; the negative electrode of the driving power supply negative power supply is connected with the cathode of the parallel diodes, and the anode of the parallel diodes is connected with the emitter of the NPN triode Q6 through the resistor R12; the base of the NPN triode Q6 is connected with the driving power supply negative power supply through the resistor R11, and the collector is connected with the analog ground; The base of the NPN triode Q7 is connected with the emitter of the NPN triode Q6 through the resistor R13, the collector is connected with the analog ground through the resistor R14, and the emitter is connected with the anode of the parallel diodes through the resistor R15; The base of the NPN triode Q8 is connected with the emitter of the NPN triode Q6 through the resistor R13, the collector is connected with the analog ground through the resistor R14, and the emitter is connected with the anode of the parallel diodes through the resistor R16; The anode of the parallel diodes is connected with the collector of the NPN triode Q2.

6. The space-borne magnetic momenter of claim 2, wherein, The sampling resistor R16 is connected in series in the power supply loop of the magnetic moment coil, the current collection circuit collects the voltage value of the sampling resistor R16, and after filtering, amplification and isolation amplification, the coil current sampling value is obtained through the A / D conversion circuit.

7. The space-borne magnetic momenter of claim 6, wherein, The current collection circuit comprises a first filter, a voltage amplifier, a second filter, an isolator and an A / D converter connected in sequence; The first filter is an RC filter, which filters the voltage value collected from the resistor R16; The voltage amplifier is a reverse proportional amplifier, which amplifies the filtered voltage signal; The second filter is a two-stage RC filter, which filters the amplified voltage signal; The isolator is a photoelectric isolator, which is connected between the second filter and the A / D converter; The A / D converter is used for A / D conversion of the isolated voltage signal to output a digital signal of the collected current.

8. Space-borne magnetic momenter according to any of claims 1-7, characterized in that, The resistance value of the three magnetic moment coils of the three-axis magnetic moment device is measured by the thermostat to obtain a function of the resistance value of the magnetic moment coil changing with temperature, which is stored in the magnetic assembly control unit.

9. The space-borne magnetic momenter of claim 8, wherein, In temperature compensation, the magnetic moment generated in the magnetic moment coil is kept unchanged by controlling the current flowing in the magnetic moment coil at different temperatures to be unchanged.

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