A testing device and method for cold gas thrusters based on the four-quadrant elastic disk method

Abstract

The application provides a cold gas thruster testing device and method based on a four-quadrant elastic disc method, and relates to the technical field of precision measurement. The device comprises a double-shaft electric displacement table, an elastic disc target, a bottom plate and a data processing system. The elastic disc target is used for intercepting the plume of the cold gas thruster. The probe unit is used for measuring the counter-thrust force borne by the target disc. The double-shaft electric displacement table is used for mounting and fixing the elastic disc target and calibrating the thrust direction angle. The data acquisition and processing system reads the voltage signal of the probe unit and processes the voltage signal to obtain the counter-thrust force borne by the four-quadrant region. The method is suitable for the cold gas thruster. The counter-thrust force borne by the four-quadrant region is analyzed to realize the measurement of the thrust size and the thrust direction angle of the cold gas thruster, and the measurement precision is effectively improved without being affected by the pipeline structure of the thruster.

Description

Technical Field

[0001] This invention relates to the field of precision measurement technology, and more specifically, to a testing device and method for cold gas propulsion based on the four-quadrant elastic disk method. Background Technology

[0002] Space science experiments are scientific experiments conducted in the space environment using carriers such as satellite platforms. The unique environment of space, including vacuum, microgravity, and strong radiation, provides unique experimental conditions and opportunities for scientific research. This makes space science experiments an important direction for human exploration of the universe. Examples include space gravitational wave detection, high-precision Earth gravity field measurement, and microgravity research projects. Due to interference from factors such as solar wind and cosmic radiation in space, scientists have proposed drag-free control methods, using micro-thrusters to compensate for external disturbances. Micro-thrusters are the main actuators for drag-free control; therefore, comprehensive and precise testing must be conducted before satellite launch to ensure the accuracy and stability of their thrust.

[0003] There are two main types of ground testing schemes for thrusters: direct method and indirect method.

[0004] The direct method involves mounting the thruster directly onto a thrust test bench and reading the thrust by converting the thruster's thrust into the test bench's response. For example, existing technology proposes a single-wire torsion pendulum test scheme, where the thruster is mounted on a torsion pendulum, and the thruster's thrust is measured by measuring the pendulum's torsion. However, since the thruster is directly fixed to the torsion pendulum, the direct method suffers from problems such as being significantly affected by the thruster's structural weight, introducing additional noise from the thruster pipeline, and being affected by the thruster's operating noise.

[0005] Indirect methods calculate the thrust of a propeller by measuring other thrust-related physical quantities, such as reverse thrust and propellant flow rate. For example, existing technologies use a plume diagnostic method, which absorbs charged plume particles from a colloidal micro-thruster using a two-dimensional electrometer array. The distribution of the plume particles is characterized by the current signal distribution of the electrometer array, thereby calculating the thrust direction angle of the micro-thruster. Another existing technology uses a reverse thrust method, which suspends a circular target on the center line of the micro-thrust plume through two fulcrums to form a pendulum. The deflection angle of the pendulum arm is detected by an optical lever, thus obtaining the thrust magnitude of the micro-thruster. However, the plume diagnostic method is only applicable to testing electric thrusters and not to cold gas thrusters, while the reverse thrust method can only test the thrust magnitude and has difficulty testing the thrust direction. Summary of the Invention

[0006] To address the issues of direct thrust testing being susceptible to interference from the propeller pipeline structure and indirect thrust testing being unable to measure the thrust direction of cold gas propellers, this invention proposes a cold gas propeller testing device and method based on the four-quadrant elastic disk method. This method indirectly tests the thrust of cold gas propellers and achieves accurate measurement of the thrust magnitude and direction angle by calculating the combination of reverse thrust in different quadrants on the four-quadrant elastic disk target.

[0007] To achieve the above-mentioned technical effects, the technical solution of the present invention is as follows:

[0008] A cold gas thruster testing device includes: a dual-axis electric displacement stage, an elastic disk target, a base plate, and a data processing system;

[0009] The dual-axis electric displacement stage is fixedly installed on the base plate. The elastic disk target is connected to the dual-axis electric displacement stage through an adapter and is installed facing the thruster. The dual-axis electric displacement stage drives the target to slide along two orthogonal vector directions, providing the elastic disk target with translational degrees of freedom in two orthogonal vectors.

[0010] The elastic disk target includes a frame unit, a target disk unit, and several probe units; the outer wall of the frame unit is connected to the biaxial electric displacement stage via an adapter; the target disk unit is fixedly installed on the surface of the frame unit, and the target disk unit includes an elastic disk and a fixing member. The elastic disk is divided into four quadrant regions, and the fixing member is used to connect the elastic disk and the frame unit; the probe units are fixedly installed inside the frame unit, and the signal input terminals of the probe units are in direct contact with the centers of the four quadrant regions of the elastic disk.

[0011] The signal input terminal of the data processing system is connected to the signal output terminal of each probe unit.

[0012] In this technical solution, the elastic disk target is used to intercept the plume of the cold gas thruster; the probe unit is used to measure the reverse thrust of the target disk; the dual-axis electric displacement stage is used for the installation and fixation of the elastic disk target and the calibration of the thrust direction angle; the data acquisition and processing system reads and processes the voltage signal of the probe unit to obtain the reverse thrust in the four quadrant regions; by analyzing the reverse thrust in the four quadrant regions, the thrust magnitude and thrust direction angle of the cold gas thruster can be measured.

[0013] Preferably, the frame unit includes a set of horizontal beams and a set of vertical beams; the probe unit and the target plate unit are fixedly connected to the horizontal beams; the vertical beams are used to support the horizontal beams, and the outer wall of the vertical beams is connected to the adapter by several sets of bolts.

[0014] Preferably, the elastic disk includes an integral outer frame, elastic beams, and four target disks, all of which are laser-cut from a single piece of metal foil material and integrally formed; the outer frame divides the elastic disk into four quadrant regions, with a target disk in each quadrant region; the elastic beams connect the target disks and the outer frame, providing support for the target disks.

[0015] Here, by improving the beam structure of the traditional single-target elastic disk target, four target disks are integrated into a four-quadrant elastic disk target, so that the elastic disk target can obtain the magnitude of the reverse thrust of each target disk in the four quadrants in a single measurement, and the relationship between the magnitude of the reverse thrust of each target disk and the magnitude of the thrust and the thrust direction angle of the thruster can be calibrated by standard plume.

[0016] Preferably, the fastener includes a first fastener and a second fastener; the outer frame is clamped and fixed between the first fastener and the second fastener, and the other end of the first fastener is fixedly connected to a set of crossbeams of the frame unit.

[0017] Preferably, the elastic beam is a zigzag beam.

[0018] Preferably, the probe unit includes a high-precision force probe, a probe adapter, and a piezoelectric displacement stage; the high-precision force probe is mounted on the piezoelectric displacement stage via the probe adapter, and the signal input end of the high-precision force probe is in direct contact with the target disk to measure the reverse thrust of the thruster plume on the target disk; the piezoelectric displacement stage is responsible for pushing the high-precision force probe to contact the target disk unit to avoid damage to the high-precision force probe due to excessive contact force; the signal output end is connected to the data processing system; the piezoelectric displacement stage is fixedly connected to the inner surface of the crossbeam by bolts.

[0019] Preferably, the probe adapter is provided with a slot, and the high-precision force probe is installed inside the slot.

[0020] Here, because the high-precision force probe is too small, it usually has only one screw hole. It needs to be installed through a probe adapter. The probe tip is restricted to be aligned with the front by setting a slot on the probe adapter, so as to avoid the probe being skewed due to the force of tightening the fixing screw during direct installation.

[0021] A test method for cold gas thrusters based on the four-quadrant elastic disk method includes:

[0022] S1. Install the cold air thruster and the cold air thruster test device opposite each other, so that the nozzle plane Σ of the cold air thruster is parallel to the surface of the elastic disc target;

[0023] S2. The coefficient η used to characterize the degree of partial elastic collision between the plume molecules and the elastic disk target, and the coefficient η of the density distribution of the thrust force on the edge of the target disk close to the coordinate axis. F ;

[0024] S3. Based on the thrust of the plume on the elastic disk target, establish an XOY coordinate system, with the four quadrants corresponding to the four target disks in the four quadrant regions of the target disk unit; record the thrust of each target disk as F1, F2, F3, and F4 according to the quadrant, and record the sum of the thrust measured by the four target disks as the total thrust F;

[0025] S4. Calculate the main shaft thrust T of the cold gas thruster based on the coefficient η and the total reverse thrust F;

[0026] S5. Based on the coefficient η F The thrust reverse forces F1, F2, F3, and F4 measured by the four target disks, and the total thrust reverse force F, are used to calculate the direction angle θ and azimuth angle of the cold gas thruster.

[0027] Preferably, η is a coefficient obtained by dividing the reverse thrust by the main shaft thrust, that is:

[0028] F = ηT

[0029] The η F The coefficient is obtained by dividing the change in the target disk's reverse thrust per unit displacement by the initial reverse thrust of the target disk.

[0030] Preferably, in step S4, the direction angle θ and azimuth angle of the cold gas thruster are... The calculation formula is as follows:

[0031]

[0032] Where d represents the distance from the nozzle plane of the cold gas thruster to the surface of the elastic disk target.

[0033] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0034] This invention proposes a testing device and method for cold gas thrusters based on the four-quadrant elastic disk method. The device includes a biaxial electric displacement stage, an elastic disk target, a base plate, and a data processing system. The elastic disk target is used to intercept the plume of the cold gas thruster. The probe unit is used to measure the reverse thrust on the target disk. The biaxial electric displacement stage is used for the installation and fixation of the elastic disk target and the calibration of the thrust direction angle. The data acquisition and processing system reads and processes the voltage signal from the probe unit to obtain the reverse thrust in the four-quadrant region. The method is adapted to cold gas thrusters. By analyzing the reverse thrust in the four-quadrant region, it realizes the measurement of the thrust magnitude and thrust direction angle of the cold gas thruster, and is not affected by the thruster pipeline structure, thus effectively improving the measurement accuracy. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the cold gas thruster testing device proposed in Embodiment 1 of the present invention;

[0036] Figure 2 This diagram illustrates the elastic disk target structure in Embodiment 1 of the present invention.

[0037] Figure 3 This diagram illustrates the frame unit structure in Embodiment 1 of the present invention.

[0038] Figure 4 This diagram illustrates the elastic disk structure in Embodiment 2 of the present invention.

[0039] Figure 5 This diagram illustrates the target disk unit structure in Embodiment 2 of the present invention.

[0040] Figure 6 This diagram illustrates the probe unit structure in Embodiment 2 of the present invention.

[0041] Figure 7 This is a schematic diagram of the test method for cold gas thrusters based on the four-quadrant elastic disk method proposed in Embodiment 3 of the present invention.

[0042] Figure 8 This diagram illustrates the thrust information of the cold gas thruster and the target reverse thrust model in Embodiment 3 of the present invention.

[0043] Figure 9 This diagram illustrates the distribution of the thrust force on the target surface in Embodiment 3 of the present invention.

[0044] Figure 10 This diagram illustrates the distribution of the thrust force on the target surface as a function of the directional angle in Embodiment 3 of the present invention.

[0045] In the diagram: 1. Dual-axis electric displacement stage; 2. Elastic disk target; 21. Frame unit; 211. Horizontal beam; 212. Vertical beam; 22. Target disk unit; 221. Elastic disk; 2211. Outer frame; 2212. Elastic beam; 2213. Target disk; 222. Fixing component; 2221. First fixing component; 2222. Second fixing component; 23. Probe unit; 231. High-precision force probe; 232. Probe adapter; 233. Piezoelectric displacement stage; 3. Base plate; 4. Adapter. Detailed Implementation

[0046] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0047] To better illustrate this embodiment, some parts of the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions;

[0048] It is understandable to those skilled in the art that some well-known details may be omitted from the accompanying drawings.

[0049] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0050] Example 1

[0051] like Figure 1 As shown, this embodiment proposes a cold gas thruster testing device, including: a dual-axis electric displacement stage 1, an elastic disk target 2, a base plate 3, and a data processing system;

[0052] The dual-axis electric displacement stage 1 is fixedly installed on the base plate 3 by bolts. The elastic disk target 2 is connected to the dual-axis electric displacement stage 1 through the adapter 4 and is installed facing the pusher. The dual-axis electric displacement stage 1 drives the elastic disk target 2 to slide along two orthogonal vector directions, providing the elastic disk target 2 with translational degrees of freedom on two orthogonal vectors.

[0053] like Figure 2 As shown, the elastic disk target 2 includes a frame unit 21, a target disk unit 22, and several probe units 23; the outer wall of the frame unit 21 is connected to the biaxial electric displacement stage 1 via a connector 4; the target disk unit 22 is fixedly installed on the surface of the frame unit 21, and the target disk unit 22 includes an elastic disk 221 and a fixing member 222. The elastic disk 221 is divided into four quadrant regions, and the fixing member 222 is used to connect the elastic disk 221 and the frame unit 21; the probe units 23 are fixedly installed inside the frame unit 21, and the signal input terminals of the probe units 23 are in direct contact with the centers of the four quadrant regions of the elastic disk 221.

[0054] The signal input terminal of the data processing system is connected to the signal output terminal of each probe unit 23.

[0055] The elastic disk target 2 is used to intercept the plume of the cold gas thruster; the probe unit 23 is used to measure the reverse thrust of the target disk 2213; the dual-axis electric displacement stage 1 is used for the installation and fixation of the elastic disk target 2 and the calibration of the thrust direction angle; the data acquisition and processing system reads and processes the voltage signal of the probe unit 23 to obtain the reverse thrust in the four quadrant regions; by analyzing the reverse thrust in the four quadrant regions, the thrust magnitude and thrust direction angle of the cold gas thruster can be measured.

[0056] In this embodiment, as Figure 3 As shown, the frame unit 21 includes a set of horizontal beams 211 and a set of vertical beams 212; the probe unit 23 and the target disk unit 22 are fixedly connected to the horizontal beams 211; the vertical beams 212 are used to support the horizontal beams 211, and the outer side wall of the vertical beams 212 is connected to the adapter 4 by several sets of bolts, which are used to adjust the position of the elastic disk target 2 during assembly. Furthermore, shallow grooves are respectively opened on the front and back of the horizontal beams 211 and the vertical beams 212 to provide redundant space for the bolts of the target disk unit 22.

[0057] The elastic disc 221 is made of high-purity aluminum foil, the base plate 3 is made of high-permeability stainless steel, and the fixing component 222, frame unit 21 and adapter 4 are made of 1060 aluminum alloy.

[0058] Example 2

[0059] In this embodiment, based on the cold gas thruster testing device proposed in Embodiment 1, the specific structure of the elastic disc target 2 is further explained.

[0060] like Figure 4 As shown, the elastic disk 221 includes an integral outer frame 2211, an elastic beam 2212, and four target disks 2213. The three are laser-cut from a single piece of metal foil material and are integrally formed. The outer frame 2211 divides the elastic disk 221 into four quadrant regions, and each quadrant region has a target disk 2213. The elastic beam 2212 is a zigzag beam, which is used to connect the target disks 2213 and the outer frame 2211 and provide support for the target disks 2213.

[0061] During the measurement process, the target disk 2213 is used to receive the plume of the cold gas thruster to obtain the reverse thrust. Its center is in contact with the tip of the high-precision force probe 231, and the reverse thrust signal is transmitted to the high-precision force probe 231.

[0062] Here, by improving the beam structure of the traditional single-target elastic disk target, four target disks 2213 are integrated into a four-quadrant elastic disk target 2, so that the elastic disk target 2 can obtain the magnitude of the reverse thrust of each target disk 2213 in the four quadrants in a single measurement, and calibrate the relationship between the magnitude of the reverse thrust of each target disk 2213 and the magnitude of the thrust and the thrust direction angle of the propeller through a standard plume.

[0063] In this embodiment, as Figure 5 As shown, the fixing member 222 includes a first fixing member 2221 and a second fixing member 2222; the outer frame 2211 is clamped and fixed between the first fixing member 2221 and the second fixing member 2222, and the other end of the first fixing member 2221 is fixedly connected to a set of crossbeams 211 of the frame unit 21. During use, the first fixing member 2221 is connected to the second fixing member 2222 by bolts to clamp and fix the elastic disc 221.

[0064] Furthermore, such as Figure 6As shown, the probe unit 23 includes a high-precision force probe 231, a probe adapter 232, and a piezoelectric displacement stage 233. Because the high-precision force probe 231 is very small, typically having only one screw hole, it is mounted on the piezoelectric displacement stage 233 via the probe adapter 232. The signal input end of the high-precision force probe 231 is in direct contact with the target disk 2213, used to measure the reverse thrust of the thruster plume on the target disk 2213. The piezoelectric displacement stage 233 is responsible for pushing the high-precision force probe 231 to contact the target disk unit 22, to prevent damage to the high-precision force probe 231 due to excessive contact force. The signal output end is connected to the data processing system. The piezoelectric displacement stage 233 is fixedly connected to the inner surface of the crossbeam 211 by bolts.

[0065] In the specific process, the probe adapter 232 is provided with a slot, and the high-precision force probe 231 is installed inside the slot. By setting the slot on the probe adapter 232, the probe tip is restricted to be aligned with the front, so as to avoid the probe being skewed due to the force of tightening the fixing screw during direct installation.

[0066] Example 3

[0067] like Figure 7 As shown, this embodiment proposes a test method for cold gas thrusters based on the four-quadrant elastic disk method, including:

[0068] S1. Install the cold air thruster and the cold air thruster test device opposite each other, so that the nozzle plane Σ of the cold air thruster is parallel to the surface of the elastic disc target;

[0069] S2. The coefficient η used to characterize the degree of partial elastic collision between the plume molecules and the elastic disk target, and the coefficient η of the density distribution of the thrust force on the edge of the target disk close to the coordinate axis. F ;

[0070] S3. Based on the thrust of the plume on the elastic disk target, establish an XOY coordinate system, with the four quadrants corresponding to the four target disks in the four quadrant regions of the target disk unit; record the thrust of each target disk as F1, F2, F3, and F4 according to the quadrant, and record the sum of the thrust measured by the four target disks as the total thrust F;

[0071] S4. Calculate the main shaft thrust T of the cold gas thruster based on the coefficient η and the total reverse thrust F;

[0072] S5. Based on the coefficient η F The thrust reverse forces F1, F2, F3, and F4 measured by the four target disks, and the total thrust reverse force F, are used to calculate the direction angle θ and azimuth angle of the cold gas thruster.

[0073] The specific reasoning steps of this method are as follows:

[0074] like Figure 8 As shown, if the thrust in the ideal thrust direction of the thruster, i.e., the magnitude of the main shaft thrust, is defined as T. When the thruster is working, the plume impacts the target, and the target experiences a reaction thrust of F. Due to partial elastic collisions between the plume molecules and the target, the reaction thrust on the target from the plume is greater than the main shaft thrust of the thruster. Therefore, according to the law of conservation of momentum, we can obtain:

[0075] F = ηT

[0076] Wherein, η is a coefficient obtained by dividing the counter-thrust by the main shaft thrust, used to characterize the degree of elastic collision, and is determined in advance through calibration during testing.

[0077] Regarding the plume thrust acting on the target, establish as follows: Figure 9 The XOY coordinate system shown represents the entire elastic disk target, with regions ABCD, AEOH, EBFO, OFCG, and HOGD corresponding to the sub-target disks in each of the four quadrants. The shaded area represents the plume region, i.e., the range of action of the reverse thrust on the target disk. Figure 9 As shown, the thrust force on each target disk is denoted as F1, F2, F3, and F4 according to the quadrant, and the total thrust force F is the sum of the thrust forces measured on the four target disks.

[0078] When the thruster's azimuth angle is zero, its plume exit direction is perpendicular to the target disk surface, and the intersection of the plume's central axis and the target surface (i.e., the center point of the total reverse thrust on the target) passes through the origin of the coordinate system. At this time, the reverse thrust on the target disks in each quadrant is equal, all being F / 4.

[0079] When the thrust direction angle of the thruster is not zero, the plume ejection direction deviates, and the target's thrust center point deviates from the origin. Let the distance from the thruster nozzle to the target be d, and the thrust direction angle be θ, with an azimuth angle of... At that time, the coordinates of the target's thrust center point are (Δx, Δy), where:

[0080]

[0081] At this point, the difference ΔF between the thrust in each quadrant and the initial thrust value F / 4 when the thrust direction angle is zero is... i for:

[0082]

[0083] Where, ρ F The surface density of the thrust force experienced by the target disk.

[0084] like Figure 10 As shown, when the target's thrust azimuth angle is zero, the offset Δx of the target's thrust center point in the Y direction is zero. The above equation can be simplified to:

[0085]

[0086] Where, η F The coefficient is obtained by dividing the change in the target disk's thrust per unit displacement by the initial thrust of the target disk. It characterizes the density distribution of the thrust on the edge of the target disk close to the coordinate axis and is determined in advance through calibration during testing.

[0087] For the target disks in the first and fourth quadrants, the sign is positive; for the target disks in the second and third quadrants, the sign is negative.

[0088] Similarly, when the target's thrust azimuth angle is π / 2, the offset Δy of the target's thrust center point in the X direction is zero, therefore:

[0089]

[0090] For target disks in the first and second quadrants, the sign is positive; for target disks in the third and fourth quadrants, the sign is negative.

[0091] Combining the above two cases, we can conclude that for a thrust direction angle of magnitude θ and an azimuth angle of... The thrusters have the following differences in the reactive thrust relative to their initial values ​​for the four quadrant target disks:

[0092]

[0093] The direction angle θ and azimuth angle of the thruster can be calculated.

[0094]

[0095] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A cold gas thruster test method based on four-quadrant elastic disk method, characterized in that, A cold gas thruster testing device, comprising a double-axis electric displacement table, an elastic disc target, a base plate, an adapter and a data processing system; The double-axis electric displacement table is fixedly installed on the base plate, and drives the elastic disc target to slide along two orthogonal vector directions; The elastic disc target comprises a frame unit, a target disc unit and a plurality of probe units; the outer wall of the frame unit is connected with the double-axis electric displacement table through the adapter; the target disc unit is fixedly installed on the surface of the frame unit, and comprises an elastic disc and a fixing member, the elastic disc is divided into four quadrant regions, and the fixing member is used for connecting the elastic disc and the frame unit; the probe units are fixedly installed inside the frame unit, and the signal input ends of the probe units are directly in contact with the centers of the four quadrant regions of the elastic disc; the elastic disc comprises an integral structure of an outer frame, elastic beams and four target discs, the outer frame divides the elastic disc into four quadrant regions, and each quadrant region is provided with a target disc; the elastic beams connect the target discs and the outer frame to provide support for the target discs; The signal input ends of the data processing system are connected with the signal output ends of each probe unit; The method comprises the following steps: S1. installing the cold gas thruster opposite to the cold gas thruster testing device, so that the nozzle plane Σ of the cold gas thruster is parallel to the surface of the elastic disc target; S2. Coefficient for characterizing the degree of partial elastic collisions between plume molecules and the elastic disc target and the density distribution of the back-propulsion force on the edge of the target disc close to the coordinate axis ; S3. establishing an XOY coordinate system based on the plume counterforce borne by the elastic disc target, and the four quadrants correspond to the four target discs of the four quadrant regions of the target disc unit; the counterforce borne by each target disc is recorded as F1, F2, F3 and F4 according to the quadrant, and the sum of the counterforces measured by the four target discs is recorded as the total counterforce F; S4. The coefficient and the total counter thrust F, the main shaft thrust T of the cold gas thruster is calculated; said is the coefficient obtained by dividing the counter thrust by the main shaft thrust, i.e.: The coefficient obtained by dividing the change in the reverse thrust of the target disk under the unit displacement by the initial reverse thrust of the target disk; S5. According to the coefficients The direction angle θ and the azimuth angle φ of the cold gas thruster thrust are calculated by the measured reverse thrusts F1, F2, F3, F4 and the total reverse thrust F of the four target discs.

2. The method of claim 1, wherein, The frame unit comprises a group of cross beams and a group of vertical beams; the probe units and the target disc unit are fixedly connected with the cross beams; the vertical beams are used for supporting the cross beams, and the outer wall of the vertical beams is connected with the adapter through a plurality of groups of bolts.

3. The method of claim 1, wherein, The fixing member comprises a first fixing member and a second fixing member; the outer frame is clamped and fixed between the first fixing member and the second fixing member, and the other end of the first fixing member is fixedly connected with a group of cross beams of the frame unit.

4. The method of claim 1, wherein, The elastic beam is a "Z" type beam.

5. The method of claim 1, wherein, The probe unit comprises a high-precision force probe, a probe adapter and a piezoelectric displacement table; the high-precision force probe is installed on the piezoelectric displacement table through the probe adapter, the signal input end of the high-precision force probe is directly in contact with the target disc, and the signal output end is connected with the data processing system; the piezoelectric displacement table is fixedly connected with the inner surface of the cross beam through bolts.

6. The method of claim 5, wherein, The probe adapter is provided with a clamping groove, and the high-precision force probe is installed inside the clamping groove.

7. The four-quadrant elastomeric disc based cold gas thruster test method of claim 6, wherein, In step S5, the direction angle of the cold gas thruster thrust θ and the azimuth angle φ are calculated as follows: wherein, d represents the distance of the nozzle plane of the cold gas thruster to the target surface of the elastic disc.

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