阅读说明：本技术 一种空间环境微弱电荷测量系统 (Space environment weak charge measuring system ) 是由 刘庆海 王俊峰 唐振宇 葛丽丽 李�昊 彭毓川 彭忠 李涛 于 2020-07-22 设计创作，主要内容包括：本申请公开了一种空间环境微弱电荷测量系统,包括：电荷采集前端模块,电荷采集前端模块包括探头,探头收集空间环境中的微弱电荷,电荷采集前端模块用于对探头收集的空间环境微弱电荷进行分电荷；电荷采集前端模块的输出端连接高速电荷/电压转换模块的输入端。采用该空间环境微弱电荷测量系统,测量空间环境中的微弱电荷量精准。(The application discloses weak charge measurement system of space environment includes: the charge collection front-end module comprises a probe, the probe collects weak charges in a space environment, and the charge collection front-end module is used for dividing the weak charges in the space environment collected by the probe; the output end of the charge collection front-end module is connected with the input end of the high-speed charge/voltage conversion module. By adopting the space environment weak charge measuring system, the measurement of the weak charge quantity in the space environment is accurate.)

1. A system for measuring weak charges in a space environment, comprising:

the system comprises a charge collection front-end module, a charge collection module and a charge collection module, wherein the charge collection front-end module comprises a probe, the probe collects weak charges in a space environment, and the charge collection front-end module is used for dividing the weak charges in the space environment collected by the probe;

the output end of the charge collection front-end module is connected with the input end of the high-speed charge/voltage conversion module.

2. The system for measuring weak space environment charge according to claim 1, wherein the charge collection front-end module further comprises: and one end of the fixed capacitor is grounded, and the other end of the fixed capacitor is connected with the probe.

3. The space environment weak charge measuring system according to claim 2, wherein the fixed capacitor is an organic thin film dielectric fixed capacitor.

4. The system for measuring weak space environment charge according to claim 1, wherein the high-speed charge-to-voltage conversion module comprises: the positive end of the operational amplifier is grounded, the negative end of the operational amplifier is connected with the output end of the charge collection front-end module, a feedback loop is connected between the negative end of the operational amplifier and the output end of the operational amplifier, the feedback loop and the operational amplifier form an integrating circuit, and the integrating circuit converts charges input by the charge collection front-end module into voltage.

5. The space environment weak charge measurement system according to claim 4, wherein the feedback loop includes a first resistor, a second resistor, a first voltage, and a second voltage, one end of the first resistor connected in parallel with the first voltage is connected to a negative terminal of the operational amplifier, the other end of the first resistor connected in parallel with the first voltage is connected to one end of the second resistor and one end of the second voltage, the other end of the second resistor is connected to an output terminal of the operational amplifier, and the other end of the second voltage is connected to ground.

6. The space environment weak charge measuring system according to claim 4, wherein the input impedance of the high-speed charge-to-voltage conversion module is a high input impedance.

7. The system for measuring weak space charge according to claim 4, wherein the input impedance of the high-speed charge-to-voltage conversion module is not less than 10¹⁵Europe.

8. The space environment weak charge measuring system according to any one of claims 1-7, wherein said charge collection front-end module and said high-speed charge-to-voltage conversion module are printed on a printed circuit board.

9. The space environment weak charge measuring system according to claim 8, wherein the printed circuit board is a high insulation resistance printed circuit board.

10. The system for measuring weak space environment charge according to claim 9, wherein the printed circuit board is packaged in a metal cover.

Technical Field

The invention relates to the technical field of charge measurement, in particular to a space environment weak charge measurement system.

Background

Acquiring the surface electrification condition of the material in the space plasma environment, wherein the detection data can be used for assisting satellite in-orbit fault judgment, in-orbit management and the like; the accumulated detection data can be used for providing a technical means for surface electrification risk analysis and alarm.

The specific task of a surface potential probe designed by a specific surface material is to obtain the inequality charged surface potential of a typical material of an orbital satellite, and the analysis of environmental impact correlation in combination with plasma environmental data can be used for constructing a risk early warning model.

Disclosure of Invention

In view of the above-mentioned drawbacks and deficiencies of the prior art, it is desirable to provide a space environment weak charge measurement system.

The invention provides a space environment weak charge measuring system, which comprises:

the charge collection front-end module comprises a probe, the probe collects weak charges in a space environment, and the charge collection front-end module is used for dividing the weak charges in the space environment collected by the probe;

the output end of the charge collection front-end module is connected with the input end of the high-speed charge/voltage conversion module.

In one embodiment, the charge collection front-end module further comprises: and one end of the fixed capacitor is grounded, and the other end of the fixed capacitor is connected with the probe.

In one embodiment, the fixed capacitor is an organic thin film dielectric fixed capacitor.

In one embodiment, a high speed charge-to-voltage conversion module comprises: the positive end of the operational amplifier is grounded, the negative end of the operational amplifier is connected with the output end of the charge collection front-end module, a feedback loop is connected between the negative end of the operational amplifier and the output end of the operational amplifier, the feedback loop and the operational amplifier form an integrating circuit, and the integrating circuit converts charges input by the charge collection front-end module into voltages.

In one embodiment, the feedback loop comprises a first resistor, a second resistor, a first voltage and a second voltage, one end of the first resistor connected in parallel with the first voltage is connected with the negative end of the operational amplifier, the other end of the first resistor connected in parallel with the first voltage is connected with one end of the second resistor and one end of the second voltage, the other end of the second resistor is connected with the output end of the operational amplifier, and the other end of the second voltage is grounded.

In one embodiment, the input impedance of the high speed charge-to-voltage conversion module is a high input impedance.

In one embodiment, the input impedance of the high-speed charge-to-voltage conversion module is not less than 10¹⁵Europe.

In one embodiment, the charge collection front end module and the high speed charge-to-voltage conversion module are printed on a printed circuit board.

In one embodiment, the printed circuit board is a high insulation resistance printed circuit board.

In one embodiment, the printed circuit board is packaged in a metal cover.

In the space environment weak charge measurement system provided by the application, the charge collection front-end module and the high-speed charge/voltage conversion module are adopted to form the space environment weak charge measurement system, and the weak charge amount in the space environment is measured accurately.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

fig. 1 is a schematic structural diagram of a space environment weak charge measurement system according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a charge collection front-end module according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a high-speed charge-to-voltage conversion module according to an embodiment of the invention.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

Referring to fig. 1, a schematic structural diagram of a space environment weak charge measurement system according to an embodiment of the present application is shown.

As shown in fig. 1, a system 100 for measuring weak charges in a space environment may include:

charge collection front end module 110, as shown in FIG. 2, the charge collection front end module 110 includes a probe C₁Probe C₁The charge collection front-end module 110 is used for collecting weak charges in the space environment and is used for the probe C₁Dividing the collected weak charges of the space environment into charges;

the output terminal of the charge collection front-end module 110 is connected to the input terminal of the high-speed charge/voltage conversion module 120.

Specifically, in order to reduce electric field distortion and sharp-corner discharge, the probe material can be in the shape of a circular sheet, gold plating is carried out on the back surface of the probe material to be used as an induction motor connecting core wire to be led out, and the surface layer and the back surface electrode of the probe material form an equivalent capacitor C₁。

Probe C₁A30 mm diameter, 1mm thick glass cover slip was used. Considering that the actual probe use condition is surface charging effect, the probe can be approximately considered as low frequency or direct current, and the dielectric constant of the measured material can be selected_rThus, the probe C₁Area S ═ pi r²＝706.8mm². Probe capacitance C estimated at maximum_sComprises the following steps:

probe C₁The charge collection front-end module 110 divides the space environment weak charges collected by the probe, then outputs the divided charges to the high-speed charge/voltage conversion module, the high-speed charge/voltage conversion module 120 converts the input charges into voltage, and the obtained voltage is converted into a charge value according to the capacitance of the probe, so that the weak charge quantity of the space environment is obtained.

In this embodiment, the space environment weak charge measurement system is formed by the charge collection front-end module and the high-speed charge/voltage conversion module, and the measurement of the weak charge amount in the space environment is accurate. The accurate probe charge quantity is obtained, the risks of performance reduction and damage of spacecraft materials can be effectively evaluated and reduced, and electronic equipment in the spacecraft is prevented from being interfered.

In one embodiment, with continued reference to fig. 2, the charge collection front end module 110 further comprises: fixed capacitor C₂Fixed capacitor C₂Is grounded, and fixes the capacitor C₂Another end of (2) and probe C₁Is connected to one end of a probe C₁The other end of the fixed capacitor is suspended to collect weak charges in the space environment, and the fixed capacitor is connected with the third resistor R in parallel.

Optionally, a fixed capacitor C₂The capacitor can be fixed by adopting an organic thin film medium, and the leakage current is smaller.

In the selective fixed capacitor C₂During designing the front-end module of charge collection, the temperature coefficient of the fixed capacitor should be reduced as much as possible, the temperature change of the fixed capacitor is ensured to be consistent with the surface dielectric material (outer surface) as much as possible, and according to the calculation and analysis, the organic film dielectric fixed capacitor CL21 CAST C CL21-630V-0.047 muF-J (axial direction) can be selected, the size of the capacitor is phi 9mm × 20mm, and the actual capacitance C is₂Voltage across<10V, and meets the safety requirement. Working temperature range: -55 ℃ to 100 ℃, a nominal temperature of 85 ℃, and when the fixed capacitor is subjected to electrical property tests at positive and negative extreme temperatures as specified, the fixed capacitor has a capacity at-55 ℃ and 100 ℃ which is not more than +/-10% compared with a capacity at a temperature of 25 +/-2 ℃, and the fixed capacitor has a capacity at a temperature of not more than +/-5% after a temperature shock test.

In one embodiment, as shown in fig. 3, the high-speed charge-to-voltage conversion module 120 includes: the positive end of the operational amplifier is grounded, the negative end of the operational amplifier is connected with the output end of the charge collection front-end module 110, a feedback loop is connected between the negative end of the operational amplifier and the output end of the operational amplifier, the feedback loop and the operational amplifier form an integrating circuit, and the integrating circuit converts charges input by the charge collection front-end module 110 into voltage.

Specifically, the power supply of the operational amplifier is +12v and-12 v, and the power supply of the operational amplifier is connected with the +12v and the-12 v in parallel by 0.1uf capacitors and 0.01uf capacitors respectively, wherein the 0.1uf capacitors and the 0.01uf capacitors are filter capacitors of the power supply.

The operational amplifier is used for ensuring that the charge quantity after charge division can be accurately collected, so that the input resistance is large, and the charge can be kept. Optionally, the input impedance of the high-speed charge-to-voltage conversion module is a high input impedance. Optionally, the input impedance of the high-speed charge-to-voltage conversion module is not less than 10¹⁵Europe. The operational amplifier can provide enough input impedance, and simultaneously can convert the charge quantity into the voltage quantity which is easy to collect.

In one embodiment, the feedback loop includes a first resistor R_fA second resistor R₂A first voltage C_fA second voltage C₂First resistance R_fAnd a first voltage C_fOne end of the parallel connection is connected with the negative end of the operational amplifier, and a first resistor R_fAnd a first voltage C_fThe other end of the resistor is connected with a second resistor R in parallel₂One terminal of the second voltage C₂One end of the first resistor is connected with the second resistor R₂Is connected with the output end of the operational amplifier, a second voltage C₂And the other end of the same is grounded.

When making R₂C₂Time constant and R_fC_fIs equal, the response speed of the feedback loop and R_fC_fThe response speed at 0 is equal.

According to the charging current I of the probe in the space environment, the charging time t of the probe in the space environment is known_cComprises the following steps:

where Q is the amount of charge, S is the probe area, j_netIs the current density.

And the time constant τ of the probe discharge is:

τ＝RC

r is the resistance of the probe body, and C is the capacitance of the probe.

The time constant T in the feedback loop needs to satisfy T ≧ max (T)_c,τ)。

The feedback circuit provided in the embodiment can adapt to the faster signal change of the probe, so that the measured weak electric charge of the space environment is more accurate.

In one embodiment, to ensure measurement accuracy and reduce probe charge bleed-off, the charge acquisition front-end module and the high-speed charge-to-voltage conversion module are printed on a printed circuit board. Alternatively, the printed circuit board is a high insulation resistance printed circuit board. For example, a Printed Circuit Board (PCB) material TU-752 may be used as a PCB (Printed Circuit Board) for a high insulation resistance PCB.

In one embodiment, the printed circuit board is packaged in a metal cover, and can shield interference noise and space plasma.

In the above embodiment, a process of brushing three-proofing paint or spot GD414 glue may be adopted, so as to maintain the insulation between the wires and the exposed pads.

By adopting the space environment weak charge measuring system provided by any embodiment, through multiple tests and actual measurement, the test data obtained by using the measuring means of the oscilloscope and the electrometer is real and accurate, and the weak charge change condition of the detector in the space environment can be accurately and quickly obtained.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the invention herein disclosed is not limited to the particular combination of features described above, but also encompasses other arrangements formed by any combination of the above features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.