On-orbit satellite micro-vibration measurement system for acceleration signal

Abstract

The invention relates to an in-orbit satellite micro-vibration measurement system for acceleration signals, and relates to the technical field of satellite micro-vibration research. The measurement system comprises an acceleration sensor, an integrated measurement electric box, a data transmission antenna, a ground station, a measurement and control antenna, a measurement and control antenna processing terminal machine and a central machine which are in data connection in sequence, and the central machine is also in data connection with the integrated measurement electric box. According to the in-orbit satellite micro-vibration measurement system for the acceleration signal, a method for extracting an effective vibration signal at a relatively high signal-to-noise ratio can be realized; different filtering frequencies can be set according to vibration frequencies and amplitude distribution of different vibration sources, so that vibration signals with different characteristics can be obtained; the measurement sensitivity is high, and acceleration signals with the amplitude being 0.05 mg and the frequency being 0.5 Hz or above can be collected; the system sampling range can be dynamically adjusted, the mass of the system is measured, the size is small, power consumption is low, and integration is easy to achieve.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite micro-vibration research, and in particular to an on-orbit satellite micro-vibration measurement system for acceleration signals. Background Art

[0002] Since the satellite is equipped with attitude actuators such as control moment gyroscopes and reaction flywheels, or is equipped with space antenna drive mechanisms and solar wing drive mechanisms, the instability caused by the operation of these rotating components leads to increased vibration of the satellite platform, which in turn causes the satellite attitude stability and payload performance to decline. This micro-vibration environment will cause a significant reduction in the transmission function of systems such as optical remote sensing cameras and atmospheric vertical spectrometers, and in severe cases even cause system failure. The ability to accurately measure the micro-vibration response generated by the above-mentioned rotating mechanisms is the basis for solving the satellite micro-vibration problem, which is crucial to ensuring the performance of optical payloads.

[0003] Since the acceleration level of the satellite micro-vibration environment is small and there is aliasing of interference noise, traditional ground vibration measurement equipment, such as modal meters, has problems such as low signal-to-noise ratio, inability to dynamically adjust the measurement range, large mass and volume, and high power, which makes it impossible to directly install it on the satellite platform. Summary of the invention

[0004] The present invention aims to solve the technical problems in the prior art and provides an on-orbit satellite micro-vibration measurement system for acceleration signals.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] An on-orbit satellite micro-vibration measurement system for acceleration signals, comprising: an acceleration sensor, an integrated measurement electric box, a data transmission antenna, a ground station, a measurement and control antenna, a measurement and control antenna processing terminal and a central machine, which are data-connected in sequence; the central machine is also data-connected to the integrated measurement electric box;

[0007] in:

[0008] The acceleration sensor is pasted on the surface of the vibration-sensitive load;

[0009] The integrated measuring electric box is used to collect the disturbance acceleration signal generated by the vibration source on the vibration sensitive load through the acceleration sensor;

[0010] The data transmission antenna is used to transmit the disturbance acceleration signal collected by the integrated measurement electric box to the ground station;

[0011] The ground station is used to upload the disturbance acceleration signal to the measurement and control antenna;

[0012] The measurement and control antenna is used to transmit the received disturbance acceleration signal to the measurement and control antenna processing terminal;

[0013] The measurement and control antenna processing terminal is used to transmit measurement and control instructions to the central computer;

[0014] The central computer is used to parse the measurement and control instructions, and transmit the working mode instructions and parameters of the integrated measurement box to the integrated measurement box, so that the integrated measurement box changes the working mode and the filtering frequency of the system, and realizes the collection function of different disturbance acceleration signals.

[0015] In the above technical solution, the measurement and control antenna processing terminal transmits the measurement and control instructions to the central machine through the CAN bus.

[0016] In the above technical solution, the integrated measuring electric box is provided with: a constant current driving circuit, a voltage conversion circuit, a filtering circuit, a DSP minimum system and a communication module connected in sequence; wherein the voltage conversion circuit is also connected to the IEPE circuit;

[0017] The constant current drive circuit uses voltage input and limits the current through a constant current diode;

[0018] The voltage conversion circuit is used to convert the output voltage of the acceleration sensor to the ADC sampling range, and the acceleration sensor output voltage conversion is completed by raising the reference ground voltage and resistive voltage division;

[0019] The filter circuit is used to suppress the noise aliased by the acceleration signal;

[0020] The DSP minimum system is used to perform secondary filtering processing on the interference introduced by other circuits after the filtering circuit through the RC filtering method;

[0021] The communication module is used to communicate with the central computer and the data transmission antenna.

[0022] In the above technical solution, the constant current driving circuit adopts a 24V driving voltage and limits the current through a 4mA constant current diode.

[0023] In the above technical solution, the voltage conversion circuit uses the method of raising the reference ground voltage and resistive voltage division to complete the acceleration sensor output voltage conversion, using a 1.5V reference ground, and converting the voltage range to 0.25-2.75V after 1 / 4 resistor voltage division.

[0024] In the above technical solution, the filter circuit uses an OPA365-EP operational amplifier and a SN74LV4052-Q1 multi-channel analog switch for combined filtering. The resistance range is 500 ohms, 1K ohms, 2K ohms and 4K ohms; the capacitance range is 0.1nF, 1nF, 10nF and 0.1μF.

[0025] In the above technical solution, the steps of the DSP minimum system for secondary filtering are as follows:

[0026] Step S1: Collect acceleration a(k) through AD conversion;

[0027] Step S2: Use RC filtering method to perform low-pass filtering on the acceleration:

[0028] Acceleration after low-pass filtering low (k) = α low a(k)+(1-α low ) low (k-1), a low (0) = 0, where: α low is the low-pass filter coefficient, and its relationship with the low-pass filter cutoff frequency is: T s is the sampling period;

[0029] Step S3: Use the RC filtering method to perform high-pass filtering on the acceleration after low-pass filtering:

[0030] Acceleration after high-pass filtering high (k) = α high a high (k-1)+α high (a low (k)-a low (k-1)), a high (0) = 0, where α high is the high-pass filter coefficient, and its relationship with the high-pass filter cutoff frequency is: T s is the sampling period.

[0031] In the above technical solution, the specific parameters of the secondary filtering process performed by the DSP minimum system are: α low =0.5569, low pass cutoff frequency is 100Hz, α high =0.9755, high pass cutoff frequency is 2Hz.

[0032] In the above technical solution, the DSP minimum system specifically includes: a DSP chip, a power supply circuit, a clock circuit, a reset circuit, a JTAG circuit and an ADC circuit;

[0033] in:

[0034] The model of DSP chip is TMS320F28335ZJZQ;

[0035] The power supply circuit is used to power the DSP chip;

[0036] The clock circuit is an external active crystal oscillator with a frequency of 25MHz, which is used as the DSP core clock after being multiplied by 4;

[0037] The reset circuit is an RC circuit with a pull-up resistor of 20KΩ, a pull-down capacitor of 10μF, and a time constant of 200ms;

[0038] The JTAG circuit is used to connect to the external debugging circuit, and the program can be burned and debugged online through the JTAG circuit;

[0039] The ADC circuit is the internal reference source.

[0040] The present invention has the following beneficial effects:

[0041] The on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention can realize a method for extracting effective vibration signals with a higher signal-to-noise ratio; different filter frequencies can be set according to the vibration frequencies and amplitude distributions of different vibration sources, thereby realizing the acquisition of vibration signals with different characteristics; the measurement sensitivity is high, and acceleration signals with an amplitude of 0.05 mg and a frequency of more than 0.5 Hz can be collected; the system sampling range can be dynamically adjusted, the measurement system mass and volume are small, the power consumption is low, and it is easy to realize integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0043] Figure 1 It is a schematic structural diagram of an on-orbit satellite micro-vibration measurement system for acceleration signals according to the present invention.

[0044] Figure 2 The present invention is a schematic diagram of the composition of an integrated measurement electrical box in the on-orbit satellite micro-vibration measurement system for acceleration signals.

[0045] Figure 3 The present invention is a schematic diagram of the principles of a constant current drive circuit and a voltage conversion circuit in the on-orbit satellite micro-vibration measurement system for acceleration signals.

[0046] Figure 4 The present invention is a schematic diagram of a filter circuit in an on-orbit satellite micro-vibration measurement system for acceleration signals.

[0047] Figure 5 The circuit diagram of the DSP chip in the on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention is shown in FIG. DETAILED DESCRIPTION

[0048] The inventive concept of the present invention is:

[0049] The present invention has established a micro-vibration measurement system that uses an acceleration sensor as a collection sensor and an integrated measurement box as a measurement device. Different from traditional measurement solutions such as fiber optic gyroscopes, the acceleration sensor has the characteristics of small size, light weight, and flexible measurement point arrangement. The quality of the collection end is only one tenth of that of the fiber optic gyroscope solution.

[0050] The on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention is of great significance for obtaining real on-orbit micro-vibration data and ultimately solving micro-vibration problems.

[0051] The present invention is described in detail below with reference to the accompanying drawings.

[0052] like Figure 1 As shown, the on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention is for 10 -2 g~10 -6 g satellite micro-vibration acceleration signal, and perform on-orbit satellite micro-vibration measurement. The system mainly includes: an integrated measurement electrical box and three acceleration sensors (acceleration sensor 1, acceleration sensor 2, acceleration sensor 3). The integrated measurement electrical box has a hardware acquisition circuit, which can realize data transmission and working mode setting through on-board data transmission and measurement and control channels. The integrated measurement electrical box is mainly used to realize the collection and processing of weak vibration signals. In other specific embodiments of the present invention, the number of acceleration sensors can be flexibly set according to measurement needs, and the measurement principle is the same as in the present embodiment, which will not be repeated here.

[0053] The on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention comprises: an acceleration sensor, an integrated measurement electric box, a data transmission antenna, a ground station, a measurement and control antenna, a measurement and control antenna processing terminal and a central machine which are data-connected in sequence; the central machine is also data-connected to the integrated measurement electric box;

[0054] Among them: the acceleration sensor is pasted on the surface of the vibration-sensitive load; the integrated measurement electric box is used to collect the disturbance acceleration signal generated by the vibration source on the vibration-sensitive load through the acceleration sensor; the data transmission antenna is used to transmit the disturbance acceleration signal collected by the integrated measurement electric box to the ground station; the ground station is used to upload the disturbance acceleration signal to the measurement and control antenna; the measurement and control antenna is used to transmit the received disturbance acceleration signal to the measurement and control antenna processing terminal; the measurement and control antenna processing terminal is used to transmit the measurement and control command to the central computer; the central computer is used to parse the measurement and control command, and transmit the working mode command and parameters of the integrated measurement electric box to the integrated measurement electric box, so that the integrated measurement electric box changes the working mode and the filtering frequency of the system, and realizes the collection function of different disturbance acceleration signals.

[0055] When the on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention is used on-orbit, a small acceleration sensor needs to be pasted to the surface of a vibration-sensitive load, and the working mode of the integrated measurement electric box is set to an on state.

[0056] On the one hand, when the satellite is working in orbit, the integrated measurement electric box collects the disturbance acceleration response signal on the load, and transmits the collected acceleration signal to the ground station through the digital transmission antenna, so that the ground personnel can obtain the disturbance acceleration signal at the vibration-sensitive load;

[0057] On the other hand, ground personnel upload the measurement mode and working parameters to the satellite through satellite telemetry instructions. Specifically:

[0058] First, the working mode and parameters of the integrated measuring electric box are written into a command frame;

[0059] Subsequently, the ground station uploads it to the measurement and control antenna, and the measurement and control antenna processing terminal transmits the command frame (measurement and control command) to the central computer through the CAN bus;

[0060] Finally, after the central computer parses the measurement and control instructions, it transmits the working mode instructions and parameters of the integrated measurement box to the integrated measurement box to complete the setting. The integrated measurement box changes the working mode and the filtering frequency of the system to realize the collection function of different disturbance acceleration signals.

[0061] Among them, the central computer is the core component of the satellite electronic system. It is responsible for the task scheduling and management, control and communication functions of the satellite's in-orbit operation, and has data processing capabilities; the data transmission system (including the data transmission antenna) is used to wirelessly transmit the collected disturbance acceleration signals to the ground station through coding, modulation, processing and switching technologies; the measurement and control system (including the measurement and control antenna processing terminal and the measurement and control antenna) transmits the measurement and control instructions of the ground station to the central computer through the measurement and control antenna processing terminal and the measurement and control antenna, thereby realizing the transmission of timing and control instructions.

[0062] In terms of acquisition parameter setting, the integrated measurement electrical box can select the appropriate filter frequency according to the distribution of the mechanical disturbance frequency of the on-orbit load. The micro-vibration signal acquisition and processing circuit in the integrated measurement electrical box uses voltage conversion and filtering circuits to adjust the amplification factor by changing the resistor and adjust the low-pass filter cutoff frequency by changing the capacitor. The micro-vibration signal acquisition and processing circuit can configure different amplification factors and hardware filtering parameters online according to demand. When the integrated measurement electrical box is working, the hardware circuit can be controlled by instructions to toggle the analog switch, change the size of the connected capacitor and resistor, and realize the setting of the filter frequency and amplitude.

[0063] like Figure 2As shown, in the on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention, the integrated measurement electrical box is specifically provided with: a constant current drive circuit, a voltage conversion circuit, a filter circuit, a DSP minimum system and a communication module connected in sequence; wherein the voltage conversion circuit is also connected to the IEPE circuit. DSP refers to: Digital Signal Processor. The IEPE circuit (Integrated Electronics Piezoelectric) is an acceleration sensor circuit with a power amplifier or a voltage amplifier, which is used to amplify and condition the signal generated by the piezoelectric sensor through built-in electronic devices, so that it is easier to transmit and process: the IEPE circuit is used to amplify and condition the weak electrical signal generated by the acceleration sensor to reduce noise interference; at the same time, the high impedance signal of the piezoelectric sensor is converted into a low impedance voltage signal, so that it can be transmitted through a long cable without losing signal quality.

[0064] Specifically:

[0065] In the on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention, Figure 3 As shown, the constant current driving circuit adopts voltage input and limits the current through a constant current diode. Specifically, the constant current driving circuit adopts a 24V driving voltage and limits the current through a 4mA constant current diode.

[0066] In the on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention, the voltage conversion circuit is used to convert the output voltage of the acceleration sensor to the ADC sampling range, and the acceleration sensor output voltage conversion is completed by raising the reference ground voltage and resistive voltage division. Specifically, the voltage conversion circuit uses the reference ground voltage and resistive voltage division to complete the acceleration sensor output voltage conversion, using a 1.5V reference ground, and converting the voltage range to 0.25-2.75V after 1 / 4 resistor voltage division.

[0067] In the on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention, Figure 4 As shown, the filter circuit is used to suppress the noise of acceleration signal aliasing. Specifically, the filter circuit uses OPA365-EP operational amplifier and SN74LV4052-Q1 multi-channel analog switch for combined filtering. The designed gears are from small to large. The resistance gears are 500 ohms, 1K ohms, 2K ohms, and 4K ohms, which correspond to 0.5 times, 1 times, 2 times, and 4 times respectively. The capacitance gears are designed to be 0.1nF, 1nF, 10nF, and 0.1μF, and the approximate cutoff frequencies correspond to: 1.6MHz, 160kHz, 16kHz, and 1.6kHz respectively.

[0068] In the on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention, the DSP minimum system is used to perform secondary filtering processing on the interference introduced by other circuits after the filtering circuit through the RC filtering method. The specific steps are as follows:

[0069] Step S1: Collect acceleration a(k) through AD conversion;

[0070] Step S2: Use RC filtering method to perform low-pass filtering on the acceleration:

[0071] Acceleration after low-pass filtering low (k) = α low a(k)+(1-α low ) low (k-1), a low (0) = 0, where: α low is the low-pass filter coefficient, and its relationship with the low-pass filter cutoff frequency is: T s is the sampling period;

[0072] Step S3: Use the RC filtering method to perform high-pass filtering on the acceleration after low-pass filtering:

[0073] Acceleration after high-pass filtering high (k) = α high a high (k-1)+α high (a low (k)-a low (k-1)), a high (0) = 0, where α high is the high-pass filter coefficient, and its relationship with the high-pass filter cutoff frequency is: T s is the sampling period.

[0074] The specific parameters of the DSP minimum system for secondary filtering are: α low =0.5569, low pass cutoff frequency is 100Hz, α high =0.9755, high pass cutoff frequency is 2Hz.

[0075] like Figure 5As shown in the figure, the DSP minimum system specifically includes: DSP chip, power supply circuit, clock circuit, reset circuit, JTAG circuit and ADC circuit. Among them, the DSP chip uses TMS320F28335ZJZQ; the power supply circuit is used to power the DSP chip; the clock circuit uses an external active crystal oscillator with a frequency of 25MHz, which is used as the DSP core clock after 4 times the frequency; the reset circuit uses an RC circuit with a pull-up resistor of 20KΩ, a pull-down capacitor of 10μF, and a time constant of 200ms; the ADC circuit uses an internal reference source, and the JTAG circuit is used to connect to the external debugging circuit, and the program can be burned and debugged online through the JTAG circuit. TAG (Joint Test Action Group) is an international standard test protocol, which is mainly used for internal chip testing and system simulation and debugging. JTAG technology is an embedded debugging technology, which encapsulates a special test circuit TAP (Test Access Port) inside the chip, and tests the internal nodes through a dedicated JTAG test tool. JTAG can also be used as a downloader to download software to FLASH.

[0076] In the on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention, the communication module adopts GTX and CAN communication protocols and has the ability to communicate with a central computer and a data transmission antenna.

[0077] The on-orbit satellite micro-vibration measurement system for acceleration signals of the present invention can realize a method for extracting effective vibration signals with a higher signal-to-noise ratio; different filter frequencies can be set according to the vibration frequencies and amplitude distributions of different vibration sources, thereby realizing the acquisition of vibration signals with different characteristics; the measurement sensitivity is high, and acceleration signals with an amplitude of 0.05 mg and a frequency of more than 0.5 Hz can be collected; the system sampling range can be dynamically adjusted, the measurement system mass and volume are small, the power consumption is low, and it is easy to realize integration.

[0078] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. An on-orbit satellite micro-vibration measurement system for acceleration signals, characterized in that: The system includes: an acceleration sensor, an integrated measuring electric box, a data transmission antenna, a ground station, a measurement and control antenna, a measurement and control antenna processing terminal, and a central computer, which are connected in sequence; the central computer is also connected in data with the integrated measuring electric box; in: The acceleration sensor is pasted on the surface of the vibration-sensitive load; The integrated measuring electric box is used to collect the disturbance acceleration signal generated by the vibration source on the vibration sensitive load through the acceleration sensor; The data transmission antenna is used to transmit the disturbance acceleration signal collected by the integrated measurement electric box to the ground station; The ground station is used to upload the disturbance acceleration signal to the measurement and control antenna; The measurement and control antenna is used to transmit the received disturbance acceleration signal to the measurement and control antenna processing terminal; The measurement and control antenna processing terminal is used to transmit measurement and control instructions to the central computer; The central computer is used to parse the measurement and control instructions, and transmit the working mode instructions and parameters of the integrated measurement box to the integrated measurement box, so that the integrated measurement box changes the working mode and the filtering frequency of the system, and realizes the collection function of different disturbance acceleration signals.

2. The on-orbit satellite micro-vibration measurement system for acceleration signals according to claim 1, characterized in that: The measurement and control antenna processing terminal transmits the measurement and control instructions to the central computer through the CAN bus.

3. The on-orbit satellite micro-vibration measurement system for acceleration signals according to claim 1, characterized in that: The integrated measuring electric box is provided with the following components connected in sequence: a constant current driving circuit, a voltage conversion circuit, a filtering circuit, a DSP minimum system and a communication module; the voltage conversion circuit is also connected to the IEPE circuit; The constant current drive circuit uses voltage input and limits the current through a constant current diode; The voltage conversion circuit is used to convert the output voltage of the acceleration sensor to the ADC sampling range, and the acceleration sensor output voltage conversion is completed by raising the reference ground voltage and resistive voltage division; The filter circuit is used to suppress the noise aliased by the acceleration signal; The DSP minimum system is used to perform secondary filtering processing on the interference introduced by other circuits after the filtering circuit through the RC filtering method; The communication module is used to communicate with the central computer and the data transmission antenna.

4. The on-orbit satellite micro-vibration measurement system for acceleration signals according to claim 3, characterized in that: The constant current drive circuit uses a 24V drive voltage and limits the current through a 4mA constant current diode.

5. The on-orbit satellite micro-vibration measurement system for acceleration signals according to claim 3, characterized in that: The voltage conversion circuit uses the method of raising the reference ground voltage and resistive voltage division to complete the acceleration sensor output voltage conversion. It uses a 1.5V reference ground and converts the voltage range to 0.25-2.75V after a 1 / 4 resistor voltage division.

6. The on-orbit satellite micro-vibration measurement system for acceleration signals according to claim 3, characterized in that: The filter circuit uses the OPA365-EP operational amplifier and the SN74LV4052-Q1 multi-channel analog switch for combined filtering. The resistance range is 500 ohm, 1K ohm, 2K ohm and 4K ohm; the capacitance range is 0.1nF, 1nF, 10nF and 0.1μF.

7. The on-orbit satellite micro-vibration measurement system for acceleration signals according to claim 3, characterized in that: The steps for the DSP minimum system to perform secondary filtering are: Step S1: Collect acceleration a(k) through AD conversion; Step S2: Use RC filtering method to perform low-pass filtering on the acceleration: Acceleration after low-pass filtering low (k) = α low a(k)+(1-α low ) low (k-1), a low (0) = 0, where: α low is the low-pass filter coefficient, and its relationship with the low-pass filter cutoff frequency is: T s is the sampling period; Step S3: Use the RC filtering method to perform high-pass filtering on the acceleration after low-pass filtering: Acceleration after high-pass filtering high (k) = α high a high (k-1)+α high (a low (k)-a low (k-1)), a high (0) = 0, where α high is the high-pass filter coefficient, and its relationship with the high-pass filter cutoff frequency is: T s is the sampling period.

8. The on-orbit satellite micro-vibration measurement system for acceleration signals according to claim 7, characterized in that: The specific parameters of the DSP minimum system for secondary filtering are: α low =0.5569, low pass cutoff frequency is 100Hz, α high =0.9755, high pass cutoff frequency is 2Hz.

9. The on-orbit satellite micro-vibration measurement system for acceleration signals according to claim 3, characterized in that: The DSP minimum system specifically includes: DSP chip, power supply circuit, clock circuit, reset circuit, JTAG circuit and ADC circuit; in: The model of DSP chip is TMS320F28335ZJZQ; The power supply circuit is used to power the DSP chip; The clock circuit is an external active crystal oscillator with a frequency of 25MHz, which is used as the DSP core clock after being multiplied by 4; The reset circuit is an RC circuit with a pull-up resistor of 20KΩ, a pull-down capacitor of 10μF, and a time constant of 200ms; The JTAG circuit is used to connect to the external debugging circuit, and the program can be burned and debugged online through the JTAG circuit; The ADC circuit is the internal reference source.

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