Heavy-load high-precision micro-thrust measurement method based on bionic knee joint inverted pendulum

Abstract

The invention relates to the technical field of precision mechanical measurement, and discloses a heavy-load high-precision micro-thrust measurement method based on a bionic knee-joint inverted pendulum, a micro-thruster is fixed at the center of a top plate of an inverted pendulum thrust measurement device through a customized tool, and the direction of a nozzle is perpendicular to the side surface of a C-shaped rigid arm and is parallel to the top plate; the top plate is connected with the bottoms of the lead-angle-shaped flexible hinges on the upper layer through fixing bolts, and the four lead-angle-shaped flexible hinges are arranged at the four corners of the top plate respectively and are in central symmetry. One end of the C-shaped rigid arm is connected with the top of the lead-angle-shaped flexible hinge on the upper layer, and the other end of the C-shaped rigid arm is connected with the bottom of the lead-angle-shaped flexible hinge on the lower layer. By adopting the structural design of the bionic knee-joint inverted pendulum, the lead-angle-shaped flexible hinge is in a stretched state under the action of a load, so that the measurement error caused by buckling instability is avoided, and the overall stability of the device and the thrust measurement precision are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of precision mechanical measurement, and in particular to a heavy-load high-precision micro-thrust measurement method based on a bionic knee inverted pendulum. Background Art

[0002] With the rapid development of aerospace technology, micro-thrusters, as an important part of satellite power systems, have received extensive attention. Micro-thrusters can convert various forms of energy into mechanical energy. According to different energy sources, micro-thrusters can be divided into electric thrusters, cold gas thrusters, laser thrusters and other types. These thrusters can generate thrusts ranging from sub-micronewtons to hundreds of micronewtons, and are widely used in tasks such as changing satellite orbits, attitude adjustment, and formation networking, which are crucial to ensuring the success of space missions. In such applications, the accuracy of thrust measurement is of great significance for the evaluation of thruster performance and the successful implementation of missions.

[0003] Existing thrust measurement technologies mainly use thrust test benches such as gravity pendulums and torsion balances to convert the thrust of the propeller into deformation variables, and calculate the thrust magnitude by measuring the deformation variables of the test bench. However, as the integration and complexity of micro-propulsion systems continue to increase, the overall mass of the system also increases, which makes thrust testing face higher challenges. Under high load conditions, the traditional inverted pendulum thrust test bench is prone to affect the measurement accuracy due to excessive stiffness, and the test bench is in a compressed state under the load, which can easily lead to buckling instability problems. This not only reduces the sensitivity of the system, but may also cause measurement errors.

[0004] In view of the problems of buckling instability and insufficient precision in existing thrust measurement technologies, the present invention adopts the structural design of a bionic knee inverted pendulum and uses a guide-angle flexible hinge in a stretched state under load, thereby avoiding measurement errors caused by buckling instability. At the same time, the present invention also dynamically adjusts the stiffness of the system, so that the device can adapt to different load conditions and maintain high-precision thrust measurement.

[0005] In order to resolve the contradiction between heavy load and high-precision measurement and improve the sensitivity and accuracy of the thrust measurement device, a variable stiffness thrust measurement device and method based on a bionic knee inverted pendulum is provided, which has the characteristics of high sensitivity, strong stability, compact structure, no additional friction, no buckling instability, and dynamically adjustable stiffness, so as to make up for the defect of insufficient thrust measurement accuracy of the prior art under heavy load conditions. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a heavy-load high-precision micro-thrust measurement method based on a bionic knee inverted pendulum, which solves the problem of buckling instability in devices such as inverted pendulums in the prior art thrust measurement technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a heavy-load high-precision micro-thrust measuring device based on a bionic knee inverted pendulum, wherein the micro-thruster is fixed at the center of the top plate of the inverted pendulum thrust measuring device through a customized tooling, and the direction of the nozzle is perpendicular to the side of the C-shaped rigid arm and parallel to the top plate;

[0008] The top plate is connected to the bottom of the chamfered flexible hinge of the upper layer by fixing bolts, and the four chamfered flexible hinges are respectively located at the four corners of the top plate and are centrally symmetrical;

[0009] One end of the C-shaped rigid arm is connected to the top of the chamfered flexible hinge of the upper layer, and the other end is connected to the bottom of the chamfered flexible hinge of the lower layer, and the whole is parallel to the direction of gravity;

[0010] The dual-axis accelerometer is fixed at the center of the substrate by a customized tooling and is powered by an internal battery without the need to introduce an additional power supply line;

[0011] The top of the liftable support rod is fixed to the four corners of the base by screws, in a centrally symmetrical manner, and the bottom is fixed to the optical plate by screws;

[0012] One of the electrostatic combs is fixed to the top plate by a custom tooling, and the other is fixed to a multi-six-degree-of-freedom adjustment device and adjusted according to the relative posture information between the electrostatic combs provided by the industrial camera;

[0013] The non-magnetic uniform iron block is symmetrically placed on the top plate, and the non-magnetic uniform iron block is rigidly connected to the top plate by screws.

[0014] The heavy-load high-precision micro-thrust measurement method based on the bionic knee inverted pendulum includes the following steps:

[0015] Step a), constructing a bionic knee joint inverted pendulum structure consisting of a mounting top plate, a base, a C-shaped rigid arm and a chamfered flexible hinge;

[0016] Step b), installing a micro-propeller at the center of the top plate, and generating electrostatic force through an electrostatic comb and a high-voltage power supply;

[0017] Step c), measuring the displacement and tilt angle change of the frame before and after the electrostatic force is applied by a capacitive displacement sensor and a dual-axis accelerometer;

[0018] Step d), by adjusting the six-degree-of-freedom adjustment device, ensure that the relative posture of the electrostatic comb is accurate;

[0019] Step e), calculating the thrust of the micro-thruster according to the electrostatic force and displacement changes.

[0020] Preferably, the rigidity K of the stand in step c) is s Calculated by the following formula:

[0021]

[0022] Among them, V 1 is the applied voltage, k e is the electrostatic force conversion coefficient, x 2 -x 1 is the displacement difference of the gantry.

[0023] Preferably, in step b), the thrust F of the micro-thruster T Calculated by the following formula:

[0024] F T =K s ·(x 4 -x 3 )

[0025] Among them, x 4 -x 3 is the displacement difference before and after the micro-thruster works.

[0026] Preferably, the adjustment of the system stiffness in step c) is achieved by placing a non-magnetic uniform iron block on the top plate. The stiffness of the stand varies with the mass M of the non-magnetic block, and the stiffness calculation formula is:

[0027]

[0028] Among them, L h is the distance between the upper and lower flexible hinges, and g is the acceleration due to gravity.

[0029] Preferably, the maximum load-bearing mass M of step c) is max-f Determined by the following formula:

[0030]

[0031] Among them, σ yield is the yield stress of the chamfered flexible hinge material.

[0032] Preferably, in step c) the maximum load-bearing mass M of the conventional inverted pendulum stand max-c for:

[0033]

[0034] Among them, σ cr is the buckling stress of the flexible hinge material.

[0035] Preferably, the ratio η of the maximum load-bearing mass of the bionic knee inverted pendulum frame and the traditional inverted pendulum frame in step b) is:

[0036]

[0037] This ratio indicates that the bionic knee inverted pendulum frame has a higher load-bearing capacity under high load conditions.

[0038] Preferably, in step d), the relative posture of the electrostatic comb is visually adjusted by two industrial cameras placed at 90 degrees to ensure that the teeth of the electrostatic comb overlap each other and the spacing between the teeth is kept equal.

[0039] Preferably, in step e), a precision electronic balance is used to record the change in electrostatic force when different voltages are applied, and the voltage is gradually adjusted according to the reading of the electronic balance to calculate the conversion coefficient k between the working voltage and the electrostatic force. e .

[0040] The present invention provides a heavy-load high-precision micro-thrust measurement method based on a bionic knee inverted pendulum. It has the following beneficial effects:

[0041] 1. The present invention adopts the structural design of the bionic knee inverted pendulum. The guide angle flexure hinge in the present invention is in a tensile state under load, rather than a compressed state in a traditional inverted pendulum. This avoids the measurement error caused by buckling instability, greatly improving the overall stability of the device and the accuracy of thrust measurement. Even under heavy load conditions, the system can still maintain a high degree of sensitivity, adapting to the high-precision measurement requirements of sub-micronewton to 100-micronewton thrusts generated by micro-thrusters.

[0042] 2. The present invention adjusts the stiffness of the system by adding a non-magnetic uniform iron block on the top plate. This design enables the system to dynamically adjust the stiffness according to different test requirements, ensuring that the device can achieve the best measurement effect and sensitivity under different experimental conditions. This not only improves the applicability of the system, but also can effectively cope with thrust measurements under different loads.

[0043] 3. The present invention uses a dual-axis accelerometer, a six-degree-of-freedom adjustment device and a capacitive displacement sensor. The system can ensure high stability and consistency in different experimental environments. Even under less than ideal environmental conditions (such as slight vibration or environmental disturbance), the system can still maintain measurement accuracy through precision sensors and provide stable measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A perspective view of the present invention;

[0045] Figure 2 It is a three-dimensional top view schematic diagram of the present invention;

[0046] Figure 3 It is a front view of the present invention;

[0047] Figure 4 It is a right schematic diagram of the present invention;

[0048] Figure 5 It is a schematic diagram of the chamfered flexible hinge part of the present invention;

[0049] Figure 6 It is the analysis diagram of the pendulum thrust stand of the present invention;

[0050] Figure 7 It is a force deformation analysis diagram of the pendulum thrust stand of the present invention;

[0051] Figure 8 The figure is a flow chart of the method of the present invention.

[0052] Among them, 1. micro thruster; 2. top plate; 3. C-shaped rigid arm; 4. dual-axis accelerometer; 5. liftable support rod; 6. optical plate; 7. lower layer chamfered flexible hinge; 8. base; 9. electrostatic comb; 10. upper layer chamfered flexible hinge; 11. industrial camera; 12. uniform iron block without magnet. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] Embodiment 1:

[0055] Please refer to the attached Figure 1 - Attachment Figure 8 , the embodiment of the present invention provides a heavy-load high-precision micro-thrust measurement device based on a bionic knee inverted pendulum, the micro-thruster 1 is fixed at the center of the top plate of the inverted pendulum thrust measurement device through a customized tooling, the direction of the nozzle is perpendicular to the side of the C-shaped rigid arm 3 and parallel to the top plate 2;

[0056] The top plate 2 is connected to the bottom of the chamfered flexible hinge 10 of the upper layer by fixing bolts. The four chamfered flexible hinges 7 are respectively located at the four corners of the top plate 2 and are centrally symmetrical.

[0057] One end of the C-shaped rigid arm 3 is connected to the top of the chamfered flexible hinge 10 of the upper layer, and one end is connected to the bottom of the chamfered flexible hinge 7 of the lower layer, and the whole is parallel to the direction of gravity;

[0058] The dual-axis accelerometer 4 is fixed at the center of the base 8 by a custom tool and is powered by an internal battery, without the need to introduce an additional power supply line;

[0059] The top of the liftable support rod 5 is fixed to the four corners of the base 8 by screws, and is centrally symmetrical, and the bottom is fixed to the optical plate 6 by screws;

[0060] One of the electrostatic combs 9 is fixed to the top plate 2 by a custom tooling, and the other is fixed to a multi-six-degree-of-freedom adjustment device and adjusted according to the relative posture information between the electrostatic combs provided by the industrial camera 11;

[0061] The non-magnetic uniform iron block 12 is symmetrically placed on the top plate 2, and the non-magnetic uniform iron block 12 is rigidly connected to the top plate 2 by screws. The microthruster 1 is fixed at the center of the top plate of the inverted pendulum thrust measurement device through a customized tooling, and the direction of the nozzle is perpendicular to the side of the C-shaped rigid arm 3 and parallel to the top plate 2;

[0062] The top plate 2 is connected to the bottom of the chamfered flexible hinge 10 of the upper layer by fixing bolts. The four chamfered flexible hinges 7 are respectively located at the four corners of the top plate 2 and are centrally symmetrical.

[0063] One end of the C-shaped rigid arm 3 is connected to the top of the chamfered flexible hinge 10 of the upper layer, and one end is connected to the bottom of the chamfered flexible hinge 7 of the lower layer, and the whole is parallel to the direction of gravity;

[0064] The dual-axis accelerometer 4 is fixed at the center of the base 8 by a custom tool and is powered by an internal battery, without the need to introduce an additional power supply line;

[0065] The top of the liftable support rod 5 is fixed to the four corners of the base 8 by screws, and is centrally symmetrical, and the bottom is fixed to the optical plate 6 by screws;

[0066] One of the electrostatic combs 9 is fixed to the top plate 2 by a custom tooling, and the other is fixed to a multi-six-degree-of-freedom adjustment device and adjusted according to the relative posture information between the electrostatic combs provided by the industrial camera 11;

[0067] The non-magnetic uniform iron block 12 is symmetrically placed on the top plate 2, and the non-magnetic uniform iron block 12 is rigidly connected to the top plate 2 by screws.

[0068] Embodiment 2:

[0069] This embodiment provides a heavy-load high-precision micro-thrust measurement method based on a bionic knee inverted pendulum on the basis of the above embodiment;

[0070] The following steps are involved:

[0071] Step a), constructing a bionic knee joint inverted pendulum structure consisting of a mounting top plate 2, a base 8, a C-shaped rigid arm 3 and a chamfered flexible hinge;

[0072] Step b), installing a micro-propeller 1 at the center of the top plate 2, and generating electrostatic force through an electrostatic comb 9 and a high-voltage power supply;

[0073] Step c), measuring the displacement and tilt angle change of the frame before and after the electrostatic force is applied by a capacitive displacement sensor and a dual-axis accelerometer 4;

[0074] Step d), by adjusting the six-degree-of-freedom adjustment device, ensure that the relative posture of the electrostatic comb 9 is accurate;

[0075] Step e) calculating the thrust of the micro-thruster 1 according to the electrostatic force and displacement changes.

[0076] Step c) Rigidity K of the stand s Calculated by the following formula:

[0077]

[0078] Among them, V 1 is the applied voltage, k e is the electrostatic force conversion coefficient, x 2 -x 1 is the displacement difference of the gantry.

[0079] Step b) Thrust F of micro-thruster 1 T Calculated by the following formula:

[0080] F T =K s ·(x 4 -x 3 )

[0081] Among them, x 4 -x 3 is the displacement difference before and after the micro-thruster works.

[0082] Step c) The adjustment of the system stiffness is achieved by placing a non-magnetic uniform iron block 12 on the top plate 2. The stiffness of the stand varies with the mass M of the non-magnetic block. The stiffness calculation formula is:

[0083]

[0084] Among them, L h is the distance between the upper and lower flexible hinges, and g is the acceleration due to gravity.

[0085] Step c) Maximum load-bearing mass M max-f Determined by the following formula:

[0086]

[0087] Among them, σ yield is the yield stress of the chamfered flexible hinge material.

[0088] Step c) Maximum load-bearing mass M of the traditional inverted pendulum stand max-c for:

[0089]

[0090] Among them, σ cr is the buckling stress of the flexible hinge material.

[0091] Step b) The ratio η of the maximum load-bearing mass of the bionic knee joint inverted pendulum frame to the traditional inverted pendulum frame is:

[0092]

[0093] This ratio indicates that the bionic knee inverted pendulum frame has a higher load-bearing capacity under high load conditions.

[0094] Step d) The relative posture of the electrostatic comb 9 is visually adjusted by two industrial cameras placed at 90 degrees to ensure that the teeth of the electrostatic comb overlap each other and keep the spacing between the teeth equal.

[0095] Step e) Using a precision electronic balance to record the change in electrostatic force when different voltages are applied, and based on the reading of the electronic balance, gradually adjusting the voltage to calculate the conversion coefficient k between the working voltage and the electrostatic force e .

[0096] In one embodiment, the main working process of the device involved in the present invention is as follows:

[0097] The device of the present invention is constructed by using a chamfered flexible hinge, a C-shaped rigid arm 3, a top plate 2, a base 8, an electrostatic comb 9, a high-voltage power supply, a capacitive displacement sensor, an eddy current damper, etc.

[0098] Use a precision electronic balance to weigh the electrostatic attraction generated between the two electrostatic combs after applying voltage. Fix one electrostatic comb at the center of the balance tray, and fix the other electrostatic comb 9 on the six-degree-of-freedom adjustment device through a customized tooling. Use two cameras placed at a 90-degree angle to determine the relative position of the two electrostatic combs at this time, and use the six-degree-of-freedom adjustment device to adjust the posture of the electrostatic comb 9 until the teeth overlap and the spacing between the teeth is equal. The positive and negative ends of the high-voltage power supply are connected to the two electrostatic combs respectively, and then the applied voltage is changed in equal steps and maintained for a certain period of time. The changes in the electronic balance indication are recorded in turn, and the magnitude of the electrostatic force under different voltages is calculated to determine the working voltage V and the electrostatic force F. e .

[0099]

[0100] One electrostatic comb 9 is installed on one side of the swing frame, and the other electrostatic comb 9 is installed on the six-degree-of-freedom adjustment device. The relative posture of the electrostatic combs is adjusted to be consistent with that of the balance using a dual-camera visual posture adjustment solution. A voltage V is applied to the electrostatic comb 9 through a high-voltage power supply. 1, by determining the conversion factor k e The magnitude of the electrostatic force applied at this time can be obtained. The capacitive displacement sensor is used to obtain the position x of the top of the inverted pendulum frame before and after the electrostatic force is applied. 1 and x 2 , the stiffness of the device at this time can be obtained by calculation.

[0101]

[0102] The micro-thruster 1 to be tested is installed at the center of the top plate of the device. A capacitive displacement sensor is used to obtain the position x of the top of the inverted pendulum frame before and after the micro-thruster 1 generates thrust. 3 and x 4 By determining the gantry stiffness K s The thrust generated by the micro-thruster can be obtained.

[0103] F T =K s ·(x 4 -x 3 )

[0104] By placing a non-magnetic uniform iron block with a mass of M on top of the pendulum, the stiffness of the system can be changed. If the distance between the upper and lower flexible hinges is L h , then the stiffness of the gantry becomes

[0105]

[0106] Since the guide angle flexure hinges acting as the rotating shaft in this device are in a tensile state under the load gravity, the limit load is the yield stress σ of the material used for the flexure hinge yield Since the four flexible hinges on the lower layer mainly act as the rotating shaft of the platform, the maximum load-bearing mass M of the bionic knee joint inverted pendulum platform is max-f Where g is the local acceleration due to gravity.

[0107]

[0108] In the traditional inverted pendulum with the same effective structural parameters, the shaft is in a compressed state under the load gravity, so the limit load is the buckling stress σ of the material used for the flexible hinge cr , so the maximum load-bearing mass of the traditional inverted pendulum stand is M max-c for

[0109]

[0110] The ratio of the maximum load-bearing mass of the bionic knee inverted pendulum frame in the present invention to that of the traditional frame is

[0111]

[0112] In one embodiment, the device of the present invention is first constructed. The micro-thruster 1 and the non-magnetic uniform iron block 12 are respectively installed at the center and both sides of the top plate 2. The electrostatic comb 9 is fixed on one side of the top plate 2, the industrial camera 11 is installed directly above the electrostatic comb 9, and the dual-axis accelerometer 4 is installed at the center of the base 8.

[0113] The tilt state of the base 8 is measured by the dual-axis accelerometer 4 to obtain the tilt angle on the horizontal plane in the initial state, and the tilt angle is adjusted to 0 by using the liftable support rod 5 to make it parallel to the horizontal plane.

[0114] A high voltage power supply is used to apply voltage to the electrostatic comb 9, so that a potential difference ΔV is generated between the two electrostatic combs. The electrostatic force at this time is measured by a precision electronic balance as F. e , determine the working voltage V and electrostatic force F e The conversion factor k e =F E / ΔV 2 .

[0115] The stiffness of the inverted pendulum thrust gantry is calibrated using the electrostatic comb 9. A voltage V is applied to the electrostatic comb 9. 1 , obtain the displacement Δx of the top of the thrust gantry, and combine the conversion coefficient ke to get the gantry stiffness:

[0116] Get the displacement Δ of the top of the thrust gantry before and after the micro-thruster 1 works x1 According to the system stiffness K s -M, the thrust generated by the micro-thruster 1 can be obtained as: F T＝ K s -M·Δ x1

[0117] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heavy-load high-precision micro-thrust measurement device based on a bionic knee inverted pendulum, characterized in that: The micro-thruster (1) is fixed at the center of the top plate of the inverted pendulum thrust measurement device through a customized tooling, and the direction of the nozzle is perpendicular to the side of the C-shaped rigid arm (3) and parallel to the top plate (2); The top plate (2) is connected to the bottom of the chamfered flexible hinge (10) of the upper layer by means of fixing bolts, and the four chamfered flexible hinges (7) are respectively located at the four corners of the top plate (2) and are centrally symmetrical; One end of the C-shaped rigid arm (3) is connected to the top of the chamfered flexible hinge (10) of the upper layer, and the other end is connected to the bottom of the chamfered flexible hinge (7) of the lower layer, and the whole is parallel to the direction of gravity; The dual-axis accelerometer (4) is fixed at the center of the base (8) by a customized tool and is powered by an internal storage battery without the need to introduce an additional power supply line; The top of the liftable support rod (5) is fixed to the four corners of the base (8) by screws in a centrally symmetrical manner, and the bottom is fixed to the optical plate (6) by screws; One of the electrostatic combs (9) is fixed on the top plate (2) by a customized tool, and the other is fixed on a multi-six-degree-of-freedom adjustment device, and is adjusted according to the relative posture information between the electrostatic combs (9) provided by the industrial camera (11); The non-magnetic uniform iron block (12) is symmetrically placed on the top plate (2), and the non-magnetic uniform iron block (12) and the top plate (2) are rigidly connected by screws.

2. A heavy-load high-precision micro-thrust measurement method based on a bionic knee inverted pendulum, according to the heavy-load high-precision micro-thrust measurement device based on a bionic knee inverted pendulum according to claim 1, characterized in that: The following steps are involved: Step a), constructing a bionic knee joint inverted pendulum structure consisting of a mounting top plate (2), a base (8), a C-shaped rigid arm (3) and a chamfered flexible hinge; Step b), installing a micro-propeller (1) at the center of the top plate (2), and generating electrostatic force through an electrostatic comb (9) and a high-voltage power supply; Step c), measuring the displacement and tilt angle change of the frame before and after the electrostatic force is applied by means of a capacitive displacement sensor and a dual-axis accelerometer (4); Step d), by adjusting the six-degree-of-freedom adjustment device, ensuring that the relative posture of the electrostatic comb (9) is accurate; Step e), calculating the thrust of the micro-thruster (1) according to the electrostatic force and the displacement change.

3. The heavy-load high-precision micro-thrust measurement method based on the bionic knee inverted pendulum according to claim 2 is characterized in that: Step c) The rigidity K of the stand s Calculated by the following formula: Where V1 is the applied voltage, k e is the electrostatic force conversion coefficient, and x2-x1 is the displacement difference of the stage.

4. The heavy-load high-precision micro-thrust measurement method based on the bionic knee inverted pendulum according to claim 2 is characterized in that: Step b) The thrust F of the micro-thruster (1) T Calculated by the following formula: F T =K s ·(x4-x3) Among them, x4-x3 is the displacement difference before and after the micro-thruster works.

5. The heavy-load high-precision micro-thrust measurement method based on the bionic knee inverted pendulum according to claim 2 is characterized in that: The adjustment of the system stiffness in step c) is achieved by placing a non-magnetic uniform iron block (12) on the top plate (2). The stiffness of the stand varies with the mass M of the non-magnetic block. The stiffness calculation formula is: Among them, L h is the distance between the upper and lower flexible hinges, and g is the acceleration due to gravity.

6. The heavy-load high-precision micro-thrust measurement method based on the bionic knee inverted pendulum according to claim 2 is characterized in that: Step c) Maximum load-bearing mass M max-f Determined by the following formula: Among them, σ yield is the yield stress of the chamfered flexible hinge material.

7. The heavy-load high-precision micro-thrust measurement method based on the bionic knee inverted pendulum according to claim 2 is characterized in that: Step c) The maximum load-bearing mass M of the conventional inverted pendulum stand max-c for: Among them, σ cr is the buckling stress of the flexible hinge material.

8. The heavy-load high-precision micro-thrust measurement method based on the bionic knee inverted pendulum according to claim 2 is characterized in that: The ratio η of the maximum load-bearing mass of the bionic knee joint inverted pendulum frame and the traditional inverted pendulum frame in step b) is: This ratio indicates that the bionic knee inverted pendulum frame has a higher load-bearing capacity under high load conditions.

9. The heavy-load high-precision micro-thrust measurement method based on the bionic knee inverted pendulum according to claim 2 is characterized in that: In the step d), the relative posture of the electrostatic comb (9) is visually adjusted by two industrial cameras placed at 90 degrees to ensure that the teeth of the electrostatic comb overlap each other and the spacing between the teeth is kept equal.

10. The heavy-load high-precision micro-thrust measurement method based on the bionic knee inverted pendulum according to claim 2 is characterized in that: In step e), a precision electronic balance is used to record the change in electrostatic force when different voltages are applied, and the voltage is gradually adjusted according to the reading of the electronic balance to calculate the conversion coefficient k between the working voltage and the electrostatic force. e .

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