A probe structure, a thermoelectric probe using the probe, and a measurement method

Abstract

The present invention belongs to the technical field of celestial body detection equipment, and specifically relates to a probe structure, a thermoelectric probe applying the probe, and a measurement method. The probe structure includes an integrally formed hollow housing, which includes a tip, a middle section, and a tail end. The tail end is provided with a positioning structure for preventing axial and / or circumferential displacement of the probe during penetration. Inside the housing, a physical property sensing unit for detecting the thermal and electrical physical properties of lunar soil is carried, and the housing has a relatively small length-diameter ratio. The thermoelectric probe includes a thermoelectric probe unit, which includes: at least two probes, and the probes can be used separately as spare probes or cooperate together according to program settings to obtain measurement data; and a support assembly for fixing and supporting the probes. The thermoelectric probe designed by the present invention selects multiple probes with a relatively short length-diameter ratio, and has functions of penetration, sounding, and detection at the same time; through one penetration, in-situ measurement of the thermal and electrical physical properties of lunar soil can be realized simultaneously, and the measurement scope of application is wide.

Description

Technical Field:

[0001] The present invention belongs to the technical field of celestial body detection equipment, and particularly relates to a probe structure, a thermoelectric probe using the probe, and a measurement method. Background Art:

[0002] The physical and chemical properties of the surface and subsurface substances of extraterrestrial celestial bodies contain rich scientific information such as the operating state of celestial bodies and the state of the space environment. Most of the solid planets, satellites, and small celestial bodies in the solar system are covered with granular or powdery porous regolith. By conducting remote sensing detection, in-situ sampling detection, or even more direct in-situ contact detection on the celestial regolith, the physical and chemical properties of the celestial surface can be obtained, and then typical scientific information such as the formation process of celestial evolution, the geological structure of the surface and subsurface, and the state of light and atmosphere environment can be deduced.

[0003] Since the 1990s, scientists have successively used means such as ground-based radars and remote sensing satellites to detect the surface and subsurface of the high-latitude regions of the moon, and initially confirmed the possibility of the existence of water ice in the lunar polar regions. However, the current detection results all have problems such as being questionable and insufficient resolution, and it is impossible to accurately identify the occurrence state of lunar regolith water ice along the profile depth. Lunar regolith water ice can be converted into spacecraft fuel through solar energy on the one hand, can be used as a construction material for lunar bases on the other hand, and is also a necessity for the long-term survival of astronauts. Currently, the United States, India, the European Union, Russia and other countries all have clear in-situ detection and resource utilization model plans for lunar south pole water ice. China will also carry out an in-situ detection mission for lunar south pole water ice in the near future. It is planned to launch a combined lunar probe of "four probes and one satellite", and through the penetrator carried by the main probe and the water ice physical property detection payload carried by the flyby probe, obtain the water ice physical property information of the surface and the following profile, and achieve accurate in-situ exploration of water ice.

[0004] The water ice on the moon is concentrated in the permanent shadow areas at both poles. Compared with the previous sampling return detection missions of the United States and the Soviet Union, the difficulties in in-situ detection of lunar south pole water ice are as follows: (1) Lack of energy, unable to use light to provide energy for spacecraft. (2) Lack of information, the topography and geomorphology of the permanent shadow areas cannot be known through remote sensing and optical methods, and it is difficult for spacecraft to land safely in the water ice-rich areas detected by remote sensing. (3) Lack of resources, the lowest temperature at the bottom of the permanent shadow areas can reach 30K, and it is difficult for spacecraft to provide effective-duration carrying and thermal control capabilities for complex detection payloads. Therefore, there is an urgent need for a physical sensing method with low mass and power consumption costs to detect the occurrence state of lunar polar water ice. Compared with thermogravimetry and various spectrometers for secondarily retrieving water content, the thermoelectric physical property detection payload has significant characteristics such as co-body design, miniaturization, and low energy consumption. At the same time, the detection results are strongly correlated with the water content, and it is more suitable for lunar regolith water ice sounding. It has been initially applied in the model missions of the European Space Agency and NASA.

[0005] The measurement methods for the thermophysical properties of soil can be summarized as follows: remote sensing detection by aircraft or satellite, precise measurement using laboratory instruments, in-situ contact sensing, and portable on-site measurement. Currently, most of the detections of the thermoelectric properties of lunar soil are by remote sensing observation methods. The remote sensing method is a non-contact method with a wide detection range, but it suffers from problems such as insufficient spatial resolution and cloud cover. The measurement method using precise laboratory measurement instruments requires sample sampling, which causes irreversible damage to the structure of the sample itself, can only be restored to a limited extent, and when the sample is returned to Earth for laboratory measurement, it is very likely to be contaminated by the Earth's environment, resulting in less convincing data. The most suitable methods are in-situ contact sensing and portable on-site measurement, using invasive or non-invasive soil thermosensors to conduct on-site measurements of the original soil structure. Therefore, based on the in-situ contact sensing method, the present invention provides a thermoelectric probe with a compact structure, short measurement time, and high detection accuracy, providing reliable data support for the research and analysis of the thermoelectric properties of lunar soil. Summary of the Invention:

[0006] The present invention provides a probe structure, a thermoelectric probe using the probe, and a measurement method. By improving the existing probe structure, the thermoelectric probe using the probe structure can simultaneously achieve in-situ measurement of the thermal and electrical properties of lunar soil through one penetration.

[0007] The technical solution adopted by the present invention is as follows: A probe structure includes: a hollow housing integrally formed for penetrating into lunar soil for measurement in a penetration manner. The housing includes a tip, a middle section, and a tail section. The tip is conical, the middle section is cylindrical, and the tail section is provided with axial and circumferential positioning structures for preventing the probe from generating axial or / and circumferential displacement during the penetration process; and

[0008] A physical property sensing unit for detecting the thermal and electrical properties of lunar soil is installed inside the housing; and

[0009] The overall length-diameter ratio of the housing is less than three.

[0010] Preferably, the axial and circumferential positioning structures include an axial positioning boss structure and a circumferential positioning lug structure. The axial positioning boss structure extends horizontally outward with reference to the cylindrical outer wall of the middle section; the circumferential positioning lug structure is fixed on the end face of the axial positioning boss structure and extends along the axial direction of the probe.

[0011] Preferably, the physical property sensing unit includes a thermal physical property sensing unit and an electrical physical property sensing unit. The thermal physical property sensing unit includes a temperature sensor and a heating wire. The electrical physical property sensing unit includes electrode wires. The heating wire is arranged in a circular winding manner on the inner bottom of the probe. The temperature sensor is vertically inserted into the heating wire, and the winding height of the heating wire is lower than the axial positioning boss structure. Thermal conductive silicone grease covering the heating wire is filled in the inner bottom of the housing. The electrode wires are welded to the circumferential positioning boss structure. The remaining pores inside the probe are filled with sealant.

[0012] A thermoelectric probe applying the above probe includes a thermoelectric probe unit, and the thermoelectric probe unit includes:

[0013] At least two probes, which can be used separately as spare probes or cooperate together to obtain measurement data according to program settings; and

[0014] A support assembly for fixing and supporting the probes. The support assembly includes a substrate, a fixing seat, and a support seat. The substrate is inserted into the front end of the fixing seat. The probe is clamped between the substrate and the fixing seat, and the tail end of the probe is axially and circumferentially restricted. The substrate and the fixing seat are installed and fixed in the support seat, and the heating wire inside the probe is placed outside the support seat.

[0015] Preferably, adiabatic holes 1 and 2 for reducing heat conduction between the roots of the probes are respectively machined on the substrate and the fixing seat.

[0016] Preferably, the thermoelectric probe further includes a sensing and detection unit, and the sensing and detection unit includes:

[0017] The pressure sensor is installed inside the thermoelectric probe unit to detect the contact pressure between the thermoelectric probe unit and the lunar soil after penetration.

[0018] Preferably, the thermoelectric probe further includes a connection unit and a penetration unit. The penetration unit and the thermoelectric probe unit are sequentially installed in the connection unit. The penetration unit adopts a pyrotechnic penetration method. The thermoelectric probe unit is pushed by the penetration unit to penetrate the front end of the thermoelectric probe unit into the lunar soil.

[0019] Preferably, the sensing and detection unit further includes: a displacement sensor, which is arranged between the connection unit and the thermoelectric probe unit to determine whether the thermoelectric probe unit has completed penetration.

[0020] Preferably, the penetration unit includes a sealing plug, a plug, a damping piston sleeve, a piston sleeve and a piston. The plug and the damping piston sleeve are sequentially sleeved in the sealing plug. The damping piston sleeve and the plug jointly enclose a sealed space for installing the pyrotechnic actuator. The damping piston sleeve abuts against the piston in the piston sleeve. A gas accommodation cavity for accommodating the gas generated by the deflagration of the pyrotechnic actuator is provided on the rear end face adjacent to the piston and the damping piston sleeve. The thermoelectric probe unit is pushed into the lunar soil by the impact force generated by the explosion.

[0021] A measurement method for in-situ probing of the thermoelectric physical properties of lunar soil using the above-mentioned thermoelectric probe, the specific steps include:

[0022] S1: After the penetration of the penetration-type exploration instrument is completed and the whole reaches stability, start the pyrotechnic actuator. Under the pushing action of the gas after the explosion, the thermoelectric probe unit moves towards the lunar soil, so that the tip part of the middle probe is penetrated into the lunar soil, and the substrate contacts the lunar soil surface;

[0023] S2: Turn on the temperature measurement and capacitance measurement functions of the thermoelectric probe unit and continuously monitor;

[0024] S3: After the above measurement values are stable, start the measurement of thermoelectric physical properties;

[0025] S31: When measuring the thermal properties, use one probe as a spare probe and other probes as measurement probes. Use one of the measurement probes as the heat source excitation end and apply a constant power for heating, and at the same time collect the temperature data of other probes. Invert the thermal conductivity and volume heat capacity of the lunar soil through the transient single-needle method and the double-needle method;

[0026] S32: When measuring the electrical properties, use some probes as transmitting probes and the rest as receiving probes. The transmitting probes are used as the electric field excitation end and apply an excitation voltage of a certain frequency. The receiving probes are used as the electric field induction end. Through the potential data of the receiving probes, use the mutual impedance method to invert the conductivity and relative dielectric constant of the lunar soil.

[0027] S4: Calibrate the measurement data obtained by each probe with the corresponding calibration experiment carried out on the ground, so as to obtain high-precision measurement data.

[0028] The beneficial effects of the present invention are:

[0029] 1. For the probe structure designed by the present invention, its shell has a short length-to-diameter ratio. Through the short and thick shape, the probe has the functions of penetration, sounding and detection at the same time. In addition, the probe designed by the present invention can simultaneously realize the in-situ measurement of the thermal and electrical properties of the lunar soil through one penetration, so that the measurement scope is wide, and the purpose of measuring the lunar soil with low quality and low power consumption can be achieved.

[0030] 2. The thermoelectric probe designed in the present invention selects four probes, which are arranged in a circular manner, making the overall structure of the thermoelectric probe compact. Among the four probes, a spare probe is also provided according to different measurement contents, ensuring the stability of the measurement process, providing data support for the research and analysis of the water content characteristics of lunar soil. At the same time, it also avoids the problem of measurement data distortion caused by the failure of a certain probe, providing reliable data support for the inversion calculation.

[0031] 3. The thermoelectric probe designed in the present invention realizes penetration by means of pyrotechnics, which has high reliability, low mass and power consumption, and can ensure rapid penetration. In order to keep a set distance between the probes during the penetration process, the present invention modifies the probe structure. By using a probe with axial and circumferential positioning structures at the tail end, it will not produce axial or circumferential displacement during the penetration process.

[0032] 4. The present invention hinders the influence of heat transfer on measurement data by setting adiabatic holes, convex platforms, heat insulation layers, etc., ensuring the accuracy of in-situ measurement data.

[0033] 5. The thermoelectric probe designed in the present invention uses the transient method, with high measurement accuracy and short measurement time, only 5 minutes, which can meet the short-time requirements of in-situ detection. BRIEF DESCRIPTION OF THE DRAWINGS:

[0034] Figure 1 is the structural schematic diagram of the probe of the present invention;

[0035] Figure 2 is the internal structural schematic diagram of the probe;

[0036] Figure 3 is the structural schematic diagram of the thermoelectric probe of the present invention;

[0037] Figure 4 is the structural schematic diagram of the thermoelectric probe unit;

[0038] Figure 5 is Figure 4 explosion diagram of;

[0039] Figure 6 is the axonometric view among the substrate, the probe and the fixing seat;

[0040] Figure 7 is the structural schematic diagram of the substrate;

[0041] Figure 8 is the front view of the fixing seat;

[0042] Figure 9 is Figure 8 top view of;

[0043] Figure 10It is a partial cross-sectional view after the substrate, probe, and fixing seat are assembled;

[0044] Figure 11 It is a schematic diagram of the force on the thermoelectric probe unit;

[0045] Figure 12 It is a functional allocation diagram of the probe in the thermoelectric probe;

[0046] Figure 13 It is a measurement calibration experimental system;

[0047] Figure 14 It is a calibration relationship curve of the dielectric constant;

[0048] Figure 15 It is a quadratic fitting curve of the conductivity;

[0049] Figure 16 It is a quadratic fitting curve of the thermal conductivity;

[0050] Figure 17 It is a quadratic fitting curve of the volume heat capacity;

[0051] Figure 18 It is a schematic diagram of the principle of measuring the thermophysical properties of lunar soil;

[0052] Figure 19 It is a schematic diagram of the principle of measuring the electrical properties of lunar soil;

[0053] Wherein: 10 thermoelectric probe unit, 11 probe, 11-1 temperature sensor, 11-2 heating wire, 11-3 thermal conductive silicone grease, 11-4 electrode wire, 11-5 sealant, 11-6 axial positioning boss structure, 11-7 circumferential positioning bump structure, 11-8 electrode wire reserved groove, 12 support assembly, 12-1 substrate, 12-11 probe mounting hole 1, 12-12 adiabatic hole 1, 12-13 threaded hole 1, 12-14 connecting column, 12-15 outer convex groove, 12-2 fixing seat, 12-21 probe mounting hole 2, 12-22 adiabatic hole 2, 12-23 threaded hole 2, 12-24 jack, 12-25 probe limiting groove, 12-26 pressure sensor mounting groove, 12-27 threaded hole 3, 12-28 pressure sensor wire groove, 12-3 support seat, 12-31 boss, 12-32 wire hole, 12-33 slider fixing hole, 20 connecting unit, 21 housing, 22 heat insulation layer, 30 penetration unit, 31 sealing plug, 32 plug, 33 damping piston sleeve, 34 piston sleeve, 35 piston, 40 sensing and detection unit, 41 pressure sensor, 42 displacement sensor, 5 pyrotechnic actuator, 6 connecting screw, 7 slider. Specific implementation method:

[0054] Combined with the accompanying drawings in the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0055] Embodiment 1

[0056] As Figure 1 and Figure 2 shown, the present invention provides a probe, which adopts the method of invading lunar soil and uses the sensors carried inside to detect the thermal and electrical properties of lunar soil to obtain information. The lunar soil mentioned herein refers to the soil attached to the surfaces of different planets.

[0057] The material of the probe 11 is selected as titanium alloy TC4 (Ti-6Al-4V) with high hardness and good thermal and electrical conductivity, and its mechanical properties are shown in Table 1.

[0058] Table 1 Performance parameters of TC4

[0059]

[0060]

[0061] The probe 11 is designed as a hollow integral structure, and its shell includes a conical tip, a cylindrical middle part, and a tail end with axial and circumferential positioning structures connected in sequence from front to back. In order to avoid excessive stress at the tip part of the probe 11 when penetrating lunar soil, the tip end of the probe 11 is designed as a circular arc, so that the tip structure is more easily penetrated into the lunar soil during penetration. In this embodiment, the probe 11 adopts a smaller length-diameter ratio design, with the length-diameter ratio less than three, so that the distance between the probes 11 does not change during penetration and intrusion.

[0062] The tail end of the probe 11 includes an axial positioning boss structure 11-6 and a circumferential positioning bump structure 11-7. The axial positioning boss structure 11-6 is fixed to the cylindrical middle part for axial positioning of the probe 11, and the axial positioning boss structure 11-6 extends horizontally outward with the outer wall of the cylindrical middle part as the reference. The circumferential positioning bump structure 11-7 is fixed on the end face of the axial positioning boss structure 11-6 for circumferential positioning of the probe 11 and also serves as a wiring terminal for electrical measurement. The circumferential positioning bump structure 11-7 extends along the axial direction of the probe 11, and an electrode wire reserved groove 11-8 is also machined on the circumferential positioning bump structure 11-7.

[0063] Inside the housing of probe 1, a physical property sensing unit for detecting the thermal and electrical properties of lunar soil is installed. The physical property sensing unit includes a thermal property sensing unit and an electrical property sensing unit. The thermal property sensing unit includes a temperature sensor 11-1 and a heating wire 11-2. The electrical property sensing unit includes an electrode wire 11-4. The heating wire 11-2 is arranged in a circular winding manner on the inner bottom of probe 11. The temperature sensor 11-1 is vertically inserted into the heating wire 11-2, and the winding height of the heating wire 11-2 is lower than the axial positioning boss structure 11-6. Thermal conductive silicone grease 11-3 is used to fill the inner bottom of the housing to cover the heating wire 11-2 to ensure effective heat conduction. The electrode wire 11-4 is welded in the electrode wire reserved groove 11-8 of the circumferential positioning block structure 11-7. The remaining pores inside the probe 11 are filled with a sealant 11-5, and the sealant 11-5 uses an epoxy resin glue material. The sealant 11-5 is used to ensure that the temperature sensor 11-1, the heating wire 11-2, and the electrode wire 11-4 do not move inside the probe 11 and plays a protective role for them.

[0064] Embodiment 2

[0065] The present invention is a thermoelectric probe for in-situ probing of the physical properties of lunar soil. The thermoelectric probe is used to perform in-situ probing of lunar soil, and the mutual impedance method is used to measure the electrical properties of lunar soil. Using lunar soil as the medium between the capacitor plates of a capacitor, the capacitance value and resistance value of the capacitor formed by the capacitor plates and the medium between them are utilized to inversely calculate the dielectric constant and conductivity of lunar soil, providing technical support for the analysis of the composition of lunar soil and the interpretation of the moisture content.

[0066] As Figure 3 shown, the thermoelectric probe includes a connection unit 20. The connection unit 20 is used to be mounted on a driving device such as a detector or a robotic arm. The connection unit 20 includes a housing 21 and a heat insulation layer 22. The housing 21 is a hollow structure, and a mechanical interface and an electrical interface are reserved above it. A heat insulation layer 22 for heat insulation is sleeved outside the housing 21.

[0067] Inside the connection unit 20, there are a thermoelectric probe unit 10, a penetration unit 30, and a sensing and detection unit 40. The penetration unit 30 and the thermoelectric probe unit 10 are sequentially installed inside the connection unit 20. The sensing and detection unit 40 includes a pressure sensor 41 and a displacement sensor 42. The displacement sensor 42 is used to detect the displacement of the thermoelectric probe unit 10 after penetration is completed to determine whether the penetration is completed. The displacement sensor 42 is fixedly installed on the outer wall of the housing 21. A slider 7 is installed on the thermoelectric probe unit 10. The slider 7 moves synchronously with the thermoelectric probe unit 10. The displacement sensor 42 determines whether the penetration of the thermoelectric probe unit 10 is completed by detecting the displacement change of the slider 7. The pressure sensor 41 is used to detect the contact pressure between the thermoelectric probe unit 10 and the lunar soil after penetration, providing a corresponding basis for interpreting the density of the penetrated local lunar soil. It is fixedly installed inside the thermoelectric probe unit 10.

[0068] The penetration unit 30 is used to provide the kinetic energy required for the front-end thermoelectric probe unit 10 to penetrate the lunar soil. It can adopt mechanical penetration, energy storage penetration, or pyrotechnic penetration. Since the pyrotechnic penetration method has the characteristics of fast response and high reliability, this embodiment takes the pyrotechnic penetration method as an example for introduction.

[0069] The penetration unit 30 includes a sealing plug 31, a plug 32, a damping piston sleeve 33, a piston sleeve 34, and a piston 35. The plug 32 and the damping piston sleeve 33 are sequentially sleeved inside the sealing plug 31. The bottom longitudinal section of the damping piston sleeve 33 is conical. It and the plug 32 jointly enclose a sealed space for installing the pyrotechnic actuator 5. The piston sleeve 34 is installed at the front end of the damping piston sleeve 33. The end of the damping piston sleeve 33 extends into the piston sleeve 34 and abuts against the piston 35 sleeved inside the piston sleeve 34. A gas accommodation cavity for accommodating the gas generated by the deflagration of the pyrotechnic actuator 5 is opened on the rear end face of the piston 35 adjacent to the damping piston sleeve 33. The end of the damping piston sleeve 33 is arranged opposite to the gas accommodation cavity of the piston 35. A connection port for connecting with the thermoelectric probe unit 10 is machined on the front end face of the piston 35.

[0070] When the pyrotechnic actuator 5 ignites and explodes, the gas generated by the explosion passes through the conical end of the damping piston sleeve 33 and enters the gas accommodation cavity of the piston 35. The gas pushes the piston 35 and the thermoelectric probe unit 10 in front of it to move forward synchronously, so that the front end of the thermoelectric probe unit 10 penetrates into the lunar soil. The damping piston sleeve 33 can reduce the impact on the thermoelectric probe unit 10 caused by the explosion of the pyrotechnic actuator 5 and reduce the penetration speed of the thermoelectric probe unit 10, thus ensuring that the thermoelectric probe unit 10 will not produce large deformation after penetration.

[0071] As Figures 4 to 6As shown, the thermoelectric probe unit 10 includes multiple probes 11 and a support assembly 12 for fixing each probe 11. The thermal and electrical properties of lunar soil are measured through the mutual cooperation of the multiple probes 11. A connection end for cooperating with the connection port of the piston 35 is provided at the rear end of the support assembly 12. The structure of the probe 11 is the same as that described in Embodiment 1. The multiple probes 11 are annularly distributed and installed at the front end of the support assembly 12. The tail end of each probe 11 is inserted into the support assembly 12, and the tip of the probe 11 is located outside the support assembly 12, and the distance between each adjacent two probes 11 is the same.

[0072] The support assembly 12 includes a substrate 12-1, a fixing seat 12-2, and a support seat 12-3. The probe 11 is inserted on the front end face of the fixing seat 12-2. The substrate 12-1 is inserted at the front end of the fixing seat 12-2, and the fixing connection between the substrate 12-1 and the fixing seat 12-2 is realized through a connection screw 6, and the front end of the probe 11 extends out from the substrate 12-1. The fixing seat 12-2 and the substrate 12-1 are installed in the support seat 12-3. The fixing seat 12-2 is fixedly connected to the support seat 12-3 through a connection screw 6, and a part of the heating wire 11-2 in the probe 11 is located outside the support seat 12-3. The rear end of the support seat 12-3 is connected to the piston 35 through a thread. The connection screw 6 is preferably a zirconia screw.

[0073] The support seat 12-3 is a cylinder with an opening at the front end, and a threaded connection end for connecting with the piston 35 is provided at the rear end of the cylinder. To reduce the contact area between the support seat 12-3 and the outer shell 21 and effectively hinder heat transfer, convex platforms 12-31 that match the inner wall of the outer shell 21 are symmetrically provided on the outer circumference of the cylinder, and the convex platforms 12-31 are arranged along the axial direction of the cylinder. The inner diameter of the cylinder matches the outer diameter of the fixing seat 12-2. A wire routing hole 12-32 for the wire of the pressure sensor 41 and a slider fixing hole 12-33 for fixing the slider 7 are also provided on the side wall of the cylinder.

[0074] As Figure 7 shown, the substrate 12-1 is used to axially define the position of the probe 11 on the fixing seat 12-2. To make the substrate 12-1 meet the requirements of low thermal conductivity, insulation, and high mechanical strength, the substrate 12-1 is made of polyether ether ketone (PEEK), and its performance parameters are shown in Table 2.

[0075] Table 2 Performance Parameters of Polyether Ether Ketone (PEEK)

[0076] Performance Value Yield limit 97 MPa Poisson's ratio 0.2 Thermal conductivity 0.25 W / (m·K) Density <![CDATA[1.32g / cm 3 > Elastic modulus 3660 MPa

[0077] One probe mounting hole 12-11, one heat insulation hole 12-12 and one threaded hole 12-13 are machined on the substrate 12-1. The probe mounting hole 12-11 is for the probe 11 to pass through. It is machined as a stepped hole, and the side with a larger hole diameter is located at the front end of the substrate 12-1. The number and position of the probe mounting holes 12-11 correspond to those of the probe 11. In order to reduce the contact area between the surface of the probe 11 and the substrate 12-1 and reduce the heat transfer effect of the substrate 12-1, on the premise of ensuring the structural stability of the probe 11, an outward convex groove 12-15 is machined on the inner wall of the side with a larger hole diameter of the probe mounting hole 12-11. The outward convex grooves 12-15 are arranged at uniform intervals. Preferably, the interval between every two adjacent outward convex grooves 12-15 is 45°. The heat insulation hole 12-12 is a waist-shaped hole, which is used to reduce the heat conduction between the roots of the probes 11. At the same time, in order to ensure the working strength of the substrate 12-1, preferably, only two heat insulation holes 12-12 are machined on the substrate 12-1. The two heat insulation holes 12-12 are arranged horizontally in a line on the central axis of the substrate 12-1, and the probe mounting holes 12-11 are located on both sides of the heat insulation holes 12-12 arranged in a row. On the rear end face of the substrate 12-1, there are connecting columns 12-14 for interference fit with the fixed seat 12-2. Preferably, there are four connecting columns 12-14, which are symmetrically arranged at the four corners of the heat insulation holes 12-12 arranged horizontally in a line. Through the interference fit between the connecting columns 12-14 and the fixed seat 12-2, the circumferential limit between the substrate 12-1 and the fixed seat 12-2 is realized. At the same time, the substrate 12-1 and the fixed seat 12-2 are fixedly connected by connecting screws 6 to realize the axial positioning of the two. The threaded hole 12-13 is used to cooperate with the connecting screw 6 to realize the fixed connection between the substrate 12-1 and the fixed seat 12-2.

[0078] Such as Figures 8 to 10As shown, the fixing base 12-2 is used to fix and support the probe 11. The material of the fixing base 12-2 is the same polyether ether ketone (PEEK) as that of the base 12-1. The fixing base 12-2 is an integral structure, which is divided into a front end portion, a connecting portion, and a rear end portion according to different positions. The shaft diameter of the connecting portion is smaller than that of the front end portion and the rear end portion. On the front end portion, there are a probe mounting hole two 12-21 for fixedly installing the probe 11, an adiabatic hole two 12-22 for reducing heat conduction, a threaded hole two 12-23 for cooperating with the connecting screw 6, and a jack 12-24 for cooperating with the connecting column 12-14. The probe mounting hole two 12-21 and the probe mounting hole one 12-11, the adiabatic hole two 12-22 and the adiabatic hole one 12-12, and the threaded hole two 12-23 and the threaded hole one 12-13 are concentrically arranged. The number of the probe mounting holes two 12-21 is the same as the number of the probes 11, and they are arranged in a circular array centered on the axis of the fixing base 12-2. Each probe mounting hole two 12-21 is a stepped hole, and a probe limiting groove 12-25 is machined on the side wall of the stepped hole along its axial direction. When installing the probe 11, the axial positioning boss structure 11-6 of the probe 11 is installed into the probe mounting hole two 12-21. At the same time, the circumferential positioning convex block structure 11-7 of the probe 11 is placed in the probe limiting groove 12-25. Through the joint cooperation of the probe mounting hole two 12-21 and the substrate 12-1, the axial positioning of the probe 11 is realized; the circumferential positioning of the probe 11 is realized through the probe limiting groove 12-25. The function and position of the adiabatic hole two 12-22 are the same as those of the adiabatic hole one 12-12, both of which are used to reduce the heat conduction between the roots of the probes 11.

[0079] As Figure 11 shown, on the rear end portion of the fixing base 12-2, there are a pressure sensor mounting groove 12-26 for installing the pressure sensor 41 and a threaded hole three 12-27. On the pressure sensor mounting groove 12-26, there is also a pressure sensor wire groove 12-28 for placing wires. The support base 12-3 and the rear end portion of the fixing base 12-2 are fixedly connected through the cooperation of the connecting screw 6 and the threaded hole three 12-27. And through the cooperation of the support base 12-3 and the fixing base 12-2, a chamber for fixing the pressure sensor 41 is formed between the support base 12-3 and the pressure sensor mounting groove 12-28, and the pressure sensor 41 is subjected to a certain pre-pressure. After the thermoelectric probe unit 10 penetrates into the lunar soil, the resistance change of the strain resistors adsorbed on the fixing base 12-2 and the substrate 12-1 due to mechanical deformation is measured through the resistance strain gauges protruding on the upper section of the pressure sensor 41, so as to obtain the contact pressure between the thermoelectric probe unit 10 and the lunar soil.

[0080] After the substrate 12-1 and the fixing base 12-2 are assembled, the tip of the probe 11 is located outside the substrate 12-1. The inside of the probe 11 and the remaining pores at the rear of the probe mounting hole 12-21 are filled with sealant 14 until they are completely filled, so as to ensure that the positions of the components inside the probe 11 do not move.

[0081] As Figure 12 shown, in this embodiment, four probes 1 are taken as an example for introduction. According to different measurement parameters, the four probes 11 are respectively set as: probe A, probe B, probe C, and probe D.

[0082] To improve the measurement accuracy of the thermoelectric probe and verify its function at the same time, a calibration experiment is carried out on the thermoelectric probe unit 10.

[0083] As Figure 13 shown, the experimental equipment for this experiment includes: a thermoelectric probe unit 10, a liftable fixing device, an LCR meter, a paperless recorder, and a DC controllable power supply.

[0084] According to the detection function parameter indicators of the thermoelectric probe unit 10, the following experimental samples are selected: relative permittivity measurement calibration: air, n-decanol, n-hexanol, ultrapure water; conductivity measurement calibration: self-prepared brine (concentrations are 0.0247%, 0.2636%, 0.8425%, 1.1476%, 1.7624%, 2.0698% respectively); thermal conductivity measurement calibration: aerogel felt, EPS, 220# glass sand, glycerol, 5% agar hydrogel; volume heat capacity measurement calibration: aerogel felt, 220# glass sand, glycerol, water.

[0085] For the four measurement parameters to be calibrated, four rounds of calibration experiments are carried out respectively. The experimental steps are as follows:

[0086] 1. Relative permittivity measurement experiment

[0087] 1) Prepare the sample to be measured and cool it to the ambient temperature of 20 °C (except for pure water ice);

[0088] 2) Place the sample to be measured directly below the probe 11 and rotate the lifting handle to insert the probe 11 into the test sample until the substrate 12-1 is about to fit the surface of the sample;

[0089] 3) Adjust the LCR meter to the capacitance measurement mode and wait for 30S;

[0090] 4) Start the measurement and collect the stable capacitance value within 1 minute;

[0091] 5) Raise the probe 11 and clean it, and then conduct the next experiment.

[0092] 2. Conductivity measurement experiment

[0093] 1) Prepare the sample to be tested and cool it to the ambient temperature of 20 °C (except for pure water ice).

[0094] 2) Place the sample to be tested directly below the probe 11 and rotate the lifting handle to insert the probe 11 into the sample to be tested until the substrate 12-1 is about to fit the sample surface.

[0095] 3) Adjust the LCR meter to the conductivity measurement mode and wait for 30S.

[0096] 4) Start the measurement and collect the stable conductivity value within 1 minute.

[0097] 5) Raise the probe 11, clean it, and then conduct the next experiment.

[0098] 3. Thermal Conductivity Measurement Experiment

[0099] 1) Prepare the sample to be tested and cool it to the ambient temperature of 20 °C.

[0100] 2) Place the sample to be tested directly below the probe 11 and rotate the lifting handle to insert the probe 11 into the sample to be tested until the substrate 12-1 is about to fit the sample surface, and collect the temperature data of the four probes 11 in real time.

[0101] 3) Turn on the heating, with a heating power of 0.5W and a heating time of 5 minutes.

[0102] 4) Turn off the heating and wait for 1 minute.

[0103] 5) Raise the probe 11, clean it, and conduct the next experiment after the probe 11 has cooled to room temperature.

[0104] 4. Volume Heat Capacity Measurement Experiment

[0105] 1) Prepare the sample to be tested and cool it to the ambient temperature of 20 °C.

[0106] 2) Place the sample to be tested directly below the probe 11 and rotate the lifting handle to insert the probe 11 into the sample to be tested until the substrate 12-1 is about to fit the sample surface, and collect the temperature data of the four probes 11 in real time.

[0107] 3) Turn on the heating, with a heating power of 0.5W and a heating time of 5 minutes.

[0108] 4) Turn off the heating and wait for 1 minute.

[0109] 5) Raise the probe 11, clean it, and wait for the probe 11 to cool to room temperature.

[0110] Process the data of the above four rounds of calibration experiments as follows:

[0111] 1. Recording and Processing of Experimental Data for Relative Permittivity Measurement

[0112] Calculate the average value of the capacitance measurement data of the three groups of samples to be measured for 60 s respectively. Fit the average capacitance value with the theoretical relative permittivity once to obtain a linear relationship between capacitance and relative permittivity. Substitute the measured average capacitance value into the calibration relationship formula to calculate the relative permittivity after calibration, and compare it with the theoretical relative permittivity to calculate the measurement error and uncertainty after calibration. The experimental data records are shown in Table 3, and thus the calibration relationship curve of the relative permittivity as shown in Figure 14 is obtained.

[0113] Table 3 Recording Table of Experimental Data for Relative Permittivity Measurement

[0114]

[0115] Where: ε 标 --Relative permittivity value after calibration, ε 测 --Capacitance measurement value in the calibration experiment;

[0116] 2. Recording and Processing of Experimental Data for Conductivity Measurement

[0117] In the conductivity measurement experiment, for six groups of samples to be measured, the stable conductance values within 1 min were collected. It is necessary to calculate their average conductance values, fit the average conductance value with the theoretical conductivity twice to obtain a quadratic relationship between conductance and conductivity, and then substitute the measured average conductance value into the above relationship formula to calculate the calculated conductivity, and compare it with the theoretical conductivity to calculate the measurement error and uncertainty after calibration. The experimental data records are shown in Table 4, and thus the quadratic fitting curve of the conductivity as shown in Figure 15 is obtained.

[0118] Table 4 Recording Table of Experimental Data for Conductivity Measurement

[0119]

[0120] Where: σ 标 --Conductivity value after calibration, σ 测 --Conductivity measurement value in the calibration experiment;

[0121] 3. Recording and Processing of Experimental Data for Thermal Conductivity Measurement

[0122] In the thermal conductivity measurement experiment, for five groups of samples to be measured, the temperature change data of each probe 11 were collected. The transient hot wire method was used to solve the thermal conductivity of the five groups of samples to be measured. The measured thermal conductivity was quadratically fitted with its standard thermal conductivity to obtain the calibration relationship of the thermal conductivity. Then, the measured thermal conductivity was substituted into the above calibration equation to calculate the calibrated thermal conductivity, and compared with its standard thermal conductivity to calculate the measurement error and uncertainty after calibration. The experimental data are recorded in Table 5 as shown below, and thus the quadratic fitting curve of the thermal conductivity as shown in Figure 16 is obtained.

[0123] Table 5 Record Table of Experimental Data for Thermal Conductivity Measurement

[0124]

[0125]

[0126] λ 标 -- Value of thermal conductivity after calibration;

[0127] λ 测 -- Measured value of thermal conductivity in the calibration experiment;

[0128] 4. Recording and Processing of Experimental Data for Volume Heat Capacity Measurement

[0129] In the volume heat capacity measurement experiment, for four groups of samples to be measured, the temperature change data of each probe 11 were collected. The transient hot wire method was used to solve the volume heat capacity of the four groups of samples to be measured. The measured volume heat capacity was quadratically fitted with its theoretical volume heat capacity to obtain the calibration relationship of the volume heat capacity. Then, the measured volume heat capacity was substituted into the above calibration equation to calculate the calibrated volume heat capacity, and compared with its standard volume heat capacity to calculate the measurement error and uncertainty after calibration. The experimental data are recorded in Table 6 as shown below, and thus the quadratic fitting curve of the volume heat capacity as shown in Figure 17 is obtained.

[0130] Table 6 Record Table of Experimental Data for Volume Heat Capacity Measurement

[0131]

[0132]

[0133] Where: CV 标 -- Value of volume heat capacity after calibration; CV 测 -- Measured value of volume heat capacity in the calibration experiment;

[0134] The following conclusions are obtained through the above calibration experiment:

[0135] 1) There is a linear relationship between the relative permittivity measured by this thermoelectric property probe and the theoretical relative permittivity of the substance, and it can be calibrated through the following calibration equation.

[0136] ε 标 = 1.306ε 测 -4.921

[0137] 2) The conductivity measured by this thermoelectric property probe has a quadratic fitting relationship with the theoretical conductivity of the substance, and can be calibrated through the following calibration equation.

[0138] σ 标 = 10380σ 测 2 + 53.92σ 测 -0.001814

[0139] 3) The measurement uncertainty of the relative permittivity by this thermoelectric property probe is 3.58%, and the measurement uncertainty of the conductivity is 4.97%, both within the range of 10%.

[0140] 4) The thermal conductivity measured by this thermoelectric property probe has a quadratic fitting relationship with the theoretical thermal conductivity of the substance, and can be calibrated through the following calibration equation.

[0141] λ 标 = 0.03625 × λ 测 2 + 0.3847 × λ 测 -0.006266

[0142] 5) The volume heat capacity measured by this thermoelectric property probe has a quadratic fitting relationship with the theoretical volume heat capacity of the substance, and can be calibrated through the following calibration equation.

[0143] CV 标 = 0.06953 × CV 测 2 + 0.2787CV 测 -0.1301

[0144] 6) The measurement uncertainty of the relative permittivity by this thermoelectric property probe is 8.56%, and the measurement uncertainty of the conductivity is 3.7%, both within the range of 10%.

[0145] Example 3

[0146] Based on the thermoelectric probe in Example 2, a method for in-situ measurement of the thermoelectric properties of lunar soil by carrying it on an invasive exploration instrument specifically includes the following steps:

[0147] S1. After the invasive exploration instrument completes penetration and reaches overall stability, activate the pyrotechnic actuator 5. Under the pushing action of the gas after explosion, the thermoelectric probe unit 10 moves towards the lunar soil direction, so that the tip part of the middle probe 11 is penetrated into the lunar soil, and the substrate 12-1 contacts the lunar soil surface;

[0148] S2. Turn on the temperature measurement and capacitance measurement functions of the thermoelectric probe unit 10 and continuously monitor them;

[0149] S3. After the above measurement values are stable, start the characteristic measurement:

[0150] (1) When measuring the thermal properties, heat the probe A, which is the heat source excitation end, with a constant power, and at the same time collect the temperature data of the four probes 11. Invert the thermal conductivity and volume heat capacity of the lunar regolith through the transient single-needle method and the double-needle method.

[0151] Use a measurement method based on the transient hot-wire method. Three probes 11 are mainly used, and the other probe is a spare probe, which is a redundant design. In this embodiment, the probe C is used as the spare probe for introduction. Take the probe A as the main probe, apply a constant power to the heating wire 11-2 in the probe A, and record the temperature rise characteristics by the temperature sensor 11-1 in the probe 11. At the same time, the probe B adjacent to the probe A is used as the passive probe 11, and the temperature sensor 11-1 in the probe B records the temperature rise characteristics of the probe A transmitted to the probe B through the lunar regolith; since the initial temperature of the sensor is different from the initial temperature of the lunar regolith water ice, and the sensor body will also generate heat exchange with the measured medium, interfering with the measurement of the thermal physical properties, a third probe is needed for temperature compensation. Therefore, the passive probe D is used as the environmental temperature reference end, and the temperature sensor 11-1 in the probe D records the environmental compensation temperature characteristics. Whether it is the temperature change measured by the temperature sensor 11-1 in the main probe A or the passive probe B, the temperature change data measured by the passive probe D needs to be subtracted to eliminate the influence of the environment and the sensor temperature, so as to obtain the true temperature rise data. Given the heating power of the main probe A, according to the temperature rise characteristics of the probe A, the thermal conductivity and volume heat capacity data of the lunar regolith water ice can be inverted, but the accuracy of the volume heat capacity data is not high and can be used as a reference; given the heating power of the main probe A and the distance from the passive probe B, according to the temperature rise characteristics of the passive probe B, the thermal diffusivity and accurate volume heat capacity data of the lunar regolith water ice can be inverted, and the thermal conductivity can be indirectly calculated. By applying a constant power heat source to one probe 11 and recording the temperature characteristics through three probes 11, the in-situ lunar regolith volume heat capacity, thermal conductivity, thermal diffusivity and other indicators can be identified.

[0152] Principle of lunar regolith thermal property sounding:

[0153] For in-situ measurement of lunar regolith properties, the transient hot-wire probe measurement method is suitable for this exploration task. First, the measurement object is powder or granular material, and the detection and carrying condition is submersible detection, which is very consistent with the thermal detection and analysis of the linear heat source field. The transient hot-wire method usually uses a slender heating probe to approximate an infinite long linear heat source, and the thermal conductivity of the medium is obtained by analyzing the temperature response on the probe 11. This is usually called the single-probe method, also known as the hot-wire method or the linear heat source method; measuring the distance and heating the temperature response of another probe 11 at a certain distance from the probe 11, the volumetric heat capacity can be obtained. This is usually called the double-probe method; and the thermal diffusivity is the ratio of these two parameters.

[0154] Under the four-probe configuration design, by comprehensively considering the temperature gradient and measurement analysis, the thermal parameters such as thermal conductivity, heat capacity, and thermal diffusivity of the lunar regolith depth profile near the four probes 11 can be scientifically characterized. The measurement principle of the thermal physical properties of the lunar regolith depth profile is as Figure 18 shown.

[0155] Based on the heat conduction equation, substituting the temperatures at any two times into the temperature change curve and solving the equations, the calculation formula for the thermal conductivity k can be obtained:

[0156]

[0157] where: q is the heat released by the heating wire per unit length per unit time; t h is the cooling time of the sensor; t1, t2 are the two times for measuring the temperature.

[0158] After the probe is continuously heated for a period of time t1, at time t m , the temperature at a distance r from the heat source reaches the maximum T m , and the temperature rise ΔT can be calculated by the following formula:

[0159]

[0160] Taking the derivative of it and setting it to zero, t m can be solved, and the thermal diffusivity a can be calculated, as shown in the formula:

[0161]

[0162] The above formula is a function of r, t m and t0. After obtaining the thermal diffusivity a and combining them, the volumetric heat capacity CV can be obtained, as shown in the formula:

[0163]

[0164] (2) When measuring electrical properties, an excitation voltage of a certain frequency is applied to probe A, which serves as the electric field excitation terminal. By obtaining the potential data of probe B at the electric field induction terminal and using the mutual impedance method, the conductivity and relative permittivity of lunar soil are inversely calculated.

[0165] The AC four-probe method is used. That is, after determining the detection frequency f based on ground experiments and measurement results, an AC swept-frequency current of a predetermined intensity (generally taken as 0) is applied to the main transmitting probe A (i.e., the excitation electrode A), and another main transmitting probe B (i.e., the excitation electrode B) acts as the relative ground terminal. The electric field is received on the other two passive receiving probes C and probe D. According to the electric field characteristics of the two probes C and D, the potential difference information of the induction terminal probe B can be obtained, which is all complex information at this time. Using the mutual impedance theory, based on the known incident current of the main transmitting probes A / B, the relative permittivity of the lunar soil between the main transmitting probes A / B and the receiving probes C / D can be deduced; then, according to the relative relationship between the permittivity and conductivity, the conductivity of the lunar soil between the main transmitting probes A / B and the receiving probes C / D among the four probes can be obtained.

[0166] Principle of electrical property sounding of lunar soil:

[0167] Under the four-probe configuration design, through comprehensive analysis of the electric field gradient and measurement, scientific characterization of electrical parameters such as the permittivity of the lunar soil depth profile near the four probes can be obtained. Among them, the principle of electrical property measurement of the lunar soil depth profile is as Figure 18 shown.

[0168] Now, taking lunar soil as the dielectric between the capacitor plates, a square-wave voltage signal of a certain frequency is applied across the plates. By detecting the real-time voltage information of the conducting plate and the induction plate, the capacitance value C of the capacitor formed by the dielectric between the plates is calculated using the following formula. The specific measurement parameters include the square-wave voltage (V), the time t required for the induction capacitor plate to charge from the initial voltage (V i ) to the final voltage (V f ).

[0169]

[0170] In the formula, R is the adapted voltage-dividing resistance value of the lunar soil; C is the measured capacitance value of the capacitor plate (which is a corresponding function value of the lunar soil permittivity, and its specific function relationship is as the formula:

[0171] C = εL c (6)

[0172] In the above formula, L cThe medium is the inherent parameter value related to the capacitance attached to the electrode plate body, which specifically reflects the relationship between the parameters and the mapping plate spacing and the corresponding area of the electrode plate. Since the shape of the electrode plate is not ideal, the determination of this value requires calibration through corresponding calibration experiments on the ground. According to the obtained L c The specific calculation of the dielectric constant of lunar soil can be carried out with the capacitance parameter value of the electrode plate, as shown in the formula:

[0173]

[0174] The conductivity of lunar soil is measured using four probes 11. A variable alternating current is injected between the electrodes of the two emitting probes 11

[0175] I t = jωQ = i t exp(jωt) (8)

[0176] Among them,

[0177]

[0178] Q0 is the static charge, assumed to be zero.

[0179] The potential difference between the two receiving probes 11 is V r = V1 - V2. The complex impedance between the four electrodes is

[0180]

[0181] It can be abbreviated as:

[0182]

[0183] Among them, Z0 is the free space coupling impedance, and K is the geometric parameter defined by the structure, position, and direction of the quadrupole:

[0184]

[0185] For extraterrestrial celestial bodies, its complex impedance is

[0186]

[0187] In the above formula, ε is the relative dielectric constant:

[0188] ε = ε r -jε i (14)

[0189] Among them,

[0190]

[0191] σ is the conductivity of lunar soil, ε0 is the permittivity of vacuum, and ω is a variable angular frequency adapted to the change of measurement parameters. The permittivity of lunar soil can be easily deduced from the measured transmission impedance.

[0192] S4: After each probe 11 obtains the measurement data, the measurement results of the four parameters can be directly obtained according to the inversion formula and the calibration relation.

[0193] As described above, only the preferred specific embodiments of the present invention are provided. These specific embodiments are different implementation manners based on the overall concept of the present invention, and the protection scope 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 technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A thermoelectric probe, characterized in that, including a thermoelectric probe unit (10), the thermoelectric probe unit (10) comprising: including at least four probes (11) arranged circumferentially, with physical property sensing units for detecting the thermal and electrical properties of lunar soil mounted inside the probes (11), and which can be used individually as backup probes or cooperate together according to program settings to obtain measurement data; and a support assembly (12) for fixing and supporting the probes (11), the support assembly (12) including a substrate (12-1), a fixing seat (12-2) and a support seat (12-3), the substrate (12-1) being inserted into the front end of the fixing seat (12-2), the probe (11) being clamped between the substrate (12-1) and the fixing seat (12-2), and the tail end of the probe (11) being axially and circumferentially restricted, the substrate (12-1) and the fixing seat (12-2) being installed and fixed inside the support seat (12-3), and the heating wire (11-2) inside the probe (11) being placed outside the support seat (12-3).

2. The thermoelectric probe according to claim 1, wherein: Adiabatic holes one (12-12) and adiabatic holes two (12-22) for reducing heat conduction between the roots of the probes (11) are respectively machined on the substrate (12-1) and the fixing seat (12-2).

3. The thermoelectric probe according to claim 2, wherein: The thermoelectric probe further includes a sensing and detection unit (40), the sensing and detection unit (40) comprising: a pressure sensor (41) installed inside the thermoelectric probe unit (10) for detecting the contact pressure between the thermoelectric probe unit (10) and the lunar soil after penetration.

4. The thermoelectric probe according to claim 3, wherein: The thermoelectric probe further includes a connection unit (20) and a penetration unit (30), the penetration unit (30) and the thermoelectric probe unit (10) are sequentially installed inside the connection unit (20), the penetration unit (30) adopts a pyrotechnic penetration method, and the thermoelectric probe unit (10) is pushed by the penetration unit (30) to penetrate the front end of the thermoelectric probe unit (10) into the lunar soil.

5. The thermoelectric probe according to claim 4, wherein: The sensing and detection unit (40) further includes: a displacement sensor (42) arranged between the connection unit (20) and the thermoelectric probe unit (10) for judging whether the thermoelectric probe unit (10) has completed penetration.

6. The thermoelectric probe according to claim 5, characterized in that: The penetration unit (30) includes a sealing plug (31), a plug (32), a damping piston sleeve (33), a piston sleeve (34) and a piston (35), the plug (32) and the damping piston sleeve (33) are sequentially sleeved inside the sealing plug (31), the damping piston sleeve (33) and the plug (32) jointly enclose a sealing space for installing a pyrotechnic actuator (5), the piston (35) inside the damping piston sleeve (33) abuts against the piston sleeve (34), and a gas accommodation cavity for accommodating the gas generated by the deflagration of the pyrotechnic actuator (5) is formed on the rear end face adjacent to the damping piston sleeve (33) of the piston (35), and the thermoelectric probe unit (10) is pushed into the lunar soil by the impact force generated by the explosion.

7. A measurement method for in-situ probing of the thermoelectric physical properties of lunar soil using the thermoelectric probe according to any one of claims 1-6, characterized in that, The specific steps include: S1: After the penetration of the penetration type exploration instrument is completed and the whole reaches stability, activate the pyrotechnic actuator (5). Under the pushing action of the gas after explosion, the thermoelectric probe unit (10) moves towards the lunar soil direction, so that the tip part of the middle probe (11) is penetrated into the lunar soil, and the substrate (12-1) contacts the lunar soil surface; S2: The thermoelectric probe unit (10) has the functions of temperature measurement and capacitance measurement, and continuous monitoring is carried out; S3: After the above measurement values are stable, start the thermoelectric physical property measurement; S31: When measuring the thermal characteristics, use one probe (11) as the spare probe and other probes as the measurement probes. Take one of the measurement probes as the heat source excitation end and apply a constant power for heating. At the same time, collect the temperature data of other probes (11), and invert the thermal conductivity and volume heat capacity of the lunar soil through the transient single-needle method and double-needle method; S32: When measuring the electrical characteristics, use some probes (11) as the transmitting probes and the remaining probes (11) as the receiving probes. The transmitting probes are used as the electric field excitation ends and a certain frequency of excitation voltage is applied. The receiving probes are used as the electric field induction ends. Through the potential data of the receiving probes, use the mutual impedance method to invert the conductivity and relative permittivity of the lunar soil; S4: Calibrate the measurement data obtained by each probe (11) with the corresponding calibration experiment carried out on the ground, so as to obtain high-precision measurement data.

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