A six-degree-of-freedom strain sensing device suitable for stewart platform feedback

Abstract

The application relates to a six-freedom-degree strain sensing device suitable for Stewart platform feedback, which comprises an upper platform, an upper sensing unit, a lower sensing unit, a mounting frame, a lower platform, a first piezoelectric actuator, a second piezoelectric actuator, a third piezoelectric actuator, a fourth piezoelectric actuator, a fifth piezoelectric actuator and a sixth piezoelectric actuator; the upper platform is in the shape of a hexagon composed of three equal-length short sides and three equal-length long sides, and the short sides and the long sides are arranged at opposite positions; the upper sensing unit is connected with the upper platform; the lower sensing unit passes through the upper sensing unit sleeve and is connected with the upper platform through the upper end of the lower sensing unit sleeve; the mounting frame is composed of an upper annular mounting interface, a mounting frame first branch leg arranged in the shape of a Chinese character 'pin' under the annular mounting interface and presenting a 30-degree angle with the vertical direction, a mounting frame second branch leg and a mounting frame third branch leg. The application realizes high-precision six-freedom-degree adjustment, driving and sensing integration of the load.

Description

TECHNICAL FIELD

[0001] The application relates to a six-degree-of-freedom strain sensing device suitable for Stewart platform feedback and belongs to the technical field of precision instruments. BACKGROUND

[0002] With the rapid development of aerospace engineering and other disciplines, high-precision six-degree-of-freedom adjustment platforms are widely used in high-precision adjustment of reflector antennas, astronomical telescopes and image stabilization control, and play an increasingly important role.

[0003] The existing six-degree-of-freedom Stewart adjustment platform has a large sensor volume and weak sensing signals, which is not conducive to the lightweight application and remote feedback control of aerospace. SUMMARY

[0004] The application solves the technical problem of overcoming the shortcomings of the prior art and providing a six-degree-of-freedom strain sensing device suitable for Stewart platform feedback, realizing high-precision six-degree-of-freedom adjustment driving and sensing integration.

[0005] The technical solution of the application is as follows:

[0006] A six-degree-of-freedom strain sensing device suitable for Stewart platform feedback comprises an upper platform, an upper sensing unit, a lower sensing unit, a mounting bracket, a lower platform, a first piezoelectric actuator, a second piezoelectric actuator, a third piezoelectric actuator, a fourth piezoelectric actuator, a fifth piezoelectric actuator and a sixth piezoelectric actuator.

[0007] The upper platform has a hexagonal shape composed of three equal-length short sides and three equal-length long sides, and the short sides and the long sides are arranged at opposite positions.

[0008] The upper sensing unit is connected with the upper platform.

[0009] The lower sensing unit passes through the upper sensing unit sleeve and is connected with the upper platform through the upper end of the lower sensing unit sleeve.

[0010] The mounting bracket is composed of an upper ring-shaped mounting interface, a mounting bracket first leg arranged in a “pin” shape below the ring-shaped mounting interface and having an angle of 30° with the vertical direction, a mounting bracket second leg and a mounting bracket third leg.

[0011] The mounting bracket is connected with the upper sensing unit through the upper end of the ring-shaped mounting interface of the mounting bracket.

[0012] The lower platform has a hexagonal shape composed of three equal-length short sides and three equal-length long sides, and the short sides and the long sides are arranged at opposite positions, and is connected with the mounting bracket.

[0013] The first piezoelectric actuator consists of a middle piezoelectric rod and the first actuator flexible hinge and the second actuator flexible hinge at both ends; the second piezoelectric actuator, the third piezoelectric actuator, the fourth piezoelectric actuator, the fifth piezoelectric actuator, and the sixth piezoelectric actuator have the same structure as the first piezoelectric actuator; the first piezoelectric actuator, the second piezoelectric actuator, the third piezoelectric actuator, the fourth piezoelectric actuator, the fifth piezoelectric actuator, and the sixth piezoelectric actuator are divided into three pairs and are arranged in a "pin" shape below the three equal short sides of the upper platform and above the three equal short sides of the lower platform, and each pair of piezoelectric actuators is arranged in a "Λ" shape with an included angle of °.

[0014] Further, the upper sensing unit is connected to the upper platform through the upper ends of the first upper mounting interface of the upper sensing unit, the second upper mounting interface of the upper sensing unit, the third upper mounting interface of the upper sensing unit, and the fourth upper mounting interface of the upper sensing unit.

[0015] Further, the mounting frame is connected to the lower ends of the first "L" - shaped lower mounting interface of the upper sensing unit, the second "L" - shaped lower mounting interface of the upper sensing unit, the third "L" - shaped lower mounting interface of the upper sensing unit, the fourth "L" - shaped lower mounting interface of the upper sensing unit, the first lower mounting interface of the lower sensing unit, the second lower mounting interface of the lower sensing unit, the third lower mounting interface of the lower sensing unit, and the fourth lower mounting interface of the lower sensing unit through the upper end of the annular mounting interface of the mounting frame.

[0016] Further, the lower platform is connected to the mounting frame through the lower ends of the first leg of the mounting frame, the second leg of the mounting frame, and the third leg of the mounting frame.

[0017] Further, the upper sensing unit includes an upper sensing unit sleeve, the first upper sensing unit bending beam, the second upper sensing unit bending beam, the third upper sensing unit bending beam, and the fourth upper sensing unit bending beam that are arranged in a "cross" shape around the upper sensing unit sleeve, and the first "L" - shaped lower mounting interface, the second "L" - shaped lower mounting interface, the third "L" - shaped lower mounting interface, and the fourth "L" - shaped lower mounting interface that are arranged in a "cross" shape around the upper sensing unit sleeve and form a 45° included angle with the first upper sensing unit bending beam, the second upper sensing unit bending beam, the third upper sensing unit bending beam, and the fourth upper sensing unit bending beam arranged in a "cross" shape around the upper sensing unit sleeve.

[0018] Further, the first curved beam of the upper sensing unit comprises a front end upper sensing first mounting interface, a flexible hinge horizontally arranged at the side of the upper sensing first mounting interface, a square beam adapter connected with the flexible hinge, an upper sensing unit deformation beam connected with the beam adapter, a H-shaped beam connected with the upper sensing unit deformation beam, an upper sensing unit strain beam connected with the H-shaped beam and the upper sensing unit sleeve, an upper sensing unit first strain gauge adhered to the upper part of the upper sensing unit strain beam, and an upper sensing unit second strain gauge adhered to the lower part of the upper sensing unit strain beam.

[0019] Further, the second curved beam of the upper sensing unit, the third curved beam of the upper sensing unit, the fourth curved beam of the upper sensing unit and the first curved beam of the upper sensing unit are of the same structure.

[0020] Further, the lower sensing unit comprises a lower sensing unit sleeve, a first curved beam of the lower sensing unit arranged in the shape of a cross around the periphery of the upper sensing unit sleeve, a second curved beam of the lower sensing unit, a third curved beam of the lower sensing unit, and a fourth curved beam of the lower sensing unit.

[0021] Further, the first curved beam of the lower sensing unit comprises a lower sensing unit strain beam connected with the side of the lower sensing unit sleeve, a first flexible hinge of the lower sensing unit arranged below the front end of the lower sensing unit strain beam, a square flexible hinge adapter arranged below the first flexible hinge of the lower sensing unit, a second flexible hinge of the lower sensing unit arranged below the flexible hinge adapter, a first lower mounting interface of the lower sensing unit arranged below the second flexible hinge of the lower sensing unit, a first strain gauge of the lower sensing unit adhered to the root of the lower sensing unit strain beam, and a second strain gauge of the lower sensing unit.

[0022] Further, the second curved beam of the lower sensing unit, the third curved beam of the lower sensing unit, the fourth curved beam of the lower sensing unit and the first curved beam of the lower sensing unit are of the same structure.

[0023] The beneficial effects of the present application compared with the prior art are as follows:

[0024] (1) The present application adopts curved beams as sensing units, which can realize lightweight design of a six-degree-of-freedom platform sensor, and has the characteristics of light weight, small size and fast response;

[0025] (2) The present application adopts a Hooke's hinge as a transmission component, which realizes high-precision driving control of the upper platform, and has the characteristics of no mechanical friction and no motion gap;

[0026] (3) The present application adopts a strain sensing mode, which achieves micron-level measurement accuracy, and has the characteristics of high sensing precision and strong anti-interference ability;

[0027] (4) The present application can realize integrated design of driving and sensing, and has the characteristics of compact structure, high driving and measurement precision. Attached Figure Description

[0028] Figure 1 : The present invention is a perspective view, wherein a is a perspective view without a pair of piezoelectric actuators and the upper platform; b is a complete perspective view;

[0029] Figure 2 : 3D view of the sensor unit;

[0030] Figure 3 : 3D view of the lower sensing unit;

[0031] Figure 4 : 3D view of the mounting bracket;

[0032] Figure 5 3D diagram of a piezoelectric actuator;

[0033] Figure 6 The deformation diagram of each bending beam of the sensing unit when the present invention translates along the X (Y) direction;

[0034] Figure 7 The deformation diagram of each bending beam in the lower sensing unit when the present invention translates along the Z-axis;

[0035] Figure 8 The deformation diagram of each bending beam of the lower sensing unit when the present invention rotates around the X (Y) axis;

[0036] Figure 9 The deformation diagram of each bending beam of the sensing unit when the present invention rotates around the Z-axis. Detailed Implementation

[0037] The present invention will be further described below with reference to the embodiments.

[0038] A six-DOF strain sensing device suitable for Stewart platform feedback, such as Figure 1 As shown, the device consists of an upper platform 1, an upper sensing unit 2, a lower sensing unit 3, a mounting frame 4, a lower platform 5, a first piezoelectric actuator 6, a second piezoelectric actuator 7, a third piezoelectric actuator 8, a fourth piezoelectric actuator 9, a fifth piezoelectric actuator 10, and a sixth piezoelectric actuator 11.

[0039] The upper platform 1 is as follows Figure 1 As shown, it presents a hexagonal shape consisting of three short sides of equal length and three long sides of equal length, with the short sides and long sides arranged in opposite positions.

[0040] The upsensing unit 2, as shown in Figure 1As shown, the upper sensing unit 2 is connected to the upper platform 1 through the upper sensing unit first upper mounting interface 2-10 at the upper end, the upper sensing unit second upper mounting interface 2-18 at the upper end, the upper sensing unit third upper mounting interface 2-19 at the upper end, and the upper sensing unit fourth upper mounting interface 2-20 at the upper end. Figure 2 As shown, the upper sensing unit 2 is connected to the upper platform 1 through the upper sensing unit first upper mounting interface 2-10 at the upper end, the upper sensing unit second upper mounting interface 2-18 at the upper end, the upper sensing unit third upper mounting interface 2-19 at the upper end, and the upper sensing unit fourth upper mounting interface 2-20 at the upper end.

[0041] As shown, the upper sensing unit 2 is connected to the upper platform 1 through the upper sensing unit first upper mounting interface 2-10 at the upper end, the upper sensing unit second upper mounting interface 2-18 at the upper end, the upper sensing unit third upper mounting interface 2-19 at the upper end, and the upper sensing unit fourth upper mounting interface 2-20 at the upper end. Figure 2 As shown, the upper sensing unit 2 is connected to the upper platform 1 through the upper sensing unit first upper mounting interface 2-10 at the upper end, the upper sensing unit second upper mounting interface 2-18 at the upper end, the upper sensing unit third upper mounting interface 2-19 at the upper end, and the upper sensing unit fourth upper mounting interface 2-20 at the upper end.

[0042] As shown, the upper sensing unit 2 is connected to the upper platform 1 through the upper sensing unit first upper mounting interface 2-10 at the upper end, the upper sensing unit second upper mounting interface 2-18 at the upper end, the upper sensing unit third upper mounting interface 2-19 at the upper end, and the upper sensing unit fourth upper mounting interface 2-20 at the upper end. Figure 3 As shown, the upper sensing unit 2 is connected to the upper platform 1 through the upper sensing unit first upper mounting interface 2-10 at the upper end, the upper sensing unit second upper mounting interface 2-18 at the upper end, the upper sensing unit third upper mounting interface 2-19 at the upper end, and the upper sensing unit fourth upper mounting interface 2-20 at the upper end.

[0043] As shown, the upper sensing unit 2 is connected to the upper platform 1 through the upper sensing unit first upper mounting interface 2-10 at the upper end, the upper sensing unit second upper mounting interface 2-18 at the upper end, the upper sensing unit third upper mounting interface 2-19 at the upper end, and the upper sensing unit fourth upper mounting interface 2-20 at the upper end. Figure 3As shown in the figure, it is composed of a lower sensing unit strain beam 3-5 connected to the side of the lower sensing unit sleeve, a first flexible hinge 3-7 of the lower sensing unit arranged below the front end of the lower sensing unit strain beam 3-5, a square flexible hinge adapter platform 3-8 arranged below the first flexible hinge 3-7 of the lower sensing unit, a second flexible hinge 3-9 of the lower sensing unit arranged below the flexible hinge adapter platform 3-8, a first lower mounting interface 3-10 of the lower sensing unit arranged at the second flexible hinge 3-9 of the lower sensing unit, a first strain gauge 3-11 and a second strain gauge 3-12 of the lower sensing unit pasted at the root of the lower sensing unit strain beam 3-5; the second bending beam 3-2 of the lower sensing unit, the third bending beam 3-3 of the lower sensing unit, the fourth bending beam 3-4 of the lower sensing unit have the same structure as the first bending beam 3-1 of the lower sensing unit.

[0044] The mounting bracket 4 is as Figure 4 shown in the figure, and is composed of an upper annular mounting interface 4-1 and a first leg 4-2 of the mounting bracket, a second leg 4-3 of the mounting bracket, and a third leg 4-4 of the mounting bracket that are arranged in a "pin" shape below the annular mounting interface 4-1 and form an angle of 30° with the vertical direction. The mounting bracket 4 is connected to the lower ends of the first "L" - shaped lower mounting interface 2-5 of the upper sensing unit, the second "L" - shaped lower mounting interface 2-6 of the upper sensing unit, the third "L" - shaped lower mounting interface 2-7 of the upper sensing unit, the fourth "L" - shaped lower mounting interface 2-8 of the upper sensing unit, the first lower mounting interface 3-10 of the lower sensing unit, the second lower mounting interface 3-13 of the lower sensing unit, the third lower mounting interface 3-14 of the lower sensing unit, and the fourth lower mounting interface 3-15 of the lower sensing unit through the upper end of the mounting bracket annular mounting interface 4-1;

[0045] The lower platform 5 is as Figure 1 shown in the figure, presenting a hexagonal shape composed of three equal - length short sides and three equal - length long sides, with the short sides and long sides arranged in opposite positions, and is connected to the mounting bracket 4 through the lower ends of the first leg 4-2, the second leg 4-3, and the third leg 4-4 of the mounting bracket;

[0046] The first piezoelectric actuator 6 is as Figure 5As shown, it is composed of a middle piezoelectric rod 6-1 and actuator first flexible hinges 6-2 and actuator second flexible hinges 6-3 at both ends; the second piezoelectric actuator 7, the third piezoelectric actuator 8, the fourth piezoelectric actuator 9, the fifth piezoelectric actuator 10, and the sixth piezoelectric actuator 11 have the same structure as the first piezoelectric actuator 6; the first piezoelectric actuator 6, the second piezoelectric actuator 7, the third piezoelectric actuator 8, the fourth piezoelectric actuator 9, the fifth piezoelectric actuator 10, and the sixth piezoelectric actuator 11 are divided into three pairs and are arranged in a "pin" shape below the three equal short sides of the upper platform 1 and above the three equal short sides of the lower platform 5. Each pair of piezoelectric actuators is arranged in a "Λ" shape with an included angle of 60°, as Figure 1 shown.

[0047] A six-degree-of-freedom strain sensing method applicable to Stewart platform feedback, as Figure 6 shown. When the six-degree-of-freedom upper platform 1 translates along the X direction relative to the lower platform 5, the upper sensing unit second bending beam 2-2 and the upper sensing unit fourth bending beam 2-4 arranged in the Y direction undergo bending deformations along the X-axis direction and are symmetric about the X-axis. The strain gauges corresponding to the upper sensing unit second bending beam 2-2 and the upper sensing unit fourth bending beam 2-4 output X-direction translation feedback signals.

[0048] When the six-degree-of-freedom upper platform 1 translates along the Y direction relative to the lower platform 5, the upper sensing unit first bending beam 2-1 and the upper sensing unit third bending beam 2-3 arranged in the X direction undergo bending deformations along the Y-axis direction and are symmetric about the Y-axis. The strain gauges corresponding to the upper sensing unit first bending beam 2-1 and the upper sensing unit third bending beam 2-3 output Y-direction translation feedback signals.

[0049] As Figure 7 shown. When the six-degree-of-freedom upper platform 1 translates along the Z direction relative to the lower platform 5, the lower sensing unit first bending beam 3-1 and the lower sensing unit third bending beam 3-3 arranged in the X direction and the lower sensing unit second bending beam 3-2 and the lower sensing unit fourth bending beam 3-4 arranged in the Y direction undergo bending deformations along the Z-axis direction. The strain gauges corresponding to the lower sensing unit first bending beam 3-1, the lower sensing unit second bending beam 3-2, the lower sensing unit third bending beam 3-3, and the lower sensing unit fourth bending beam 3-4 output Z-direction translation feedback signals.

[0050] As Figure 8As shown, when the six-degree-of-freedom upper platform 1 rotates along the X direction relative to the lower platform 5, the lower sensing unit second bending beam 3-2 and the lower sensing unit fourth bending beam 3-4 arranged in the Y direction are bent and deformed about the X axis and are anti-symmetric about the center of the X axis, and the corresponding strain gauges on the lower sensing unit second bending beam 3-2 and the lower sensing unit fourth bending beam 3-4 output X direction rotation feedback signals; when the six-degree-of-freedom upper platform 1 rotates along the Y direction relative to the lower platform 5, the lower sensing unit first bending beam 3-1 and the lower sensing unit third bending beam 3-3 arranged in the X direction are bent and deformed about the Y axis and are anti-symmetric about the center of the Y axis, and the corresponding strain gauges on the lower sensing unit first bending beam 3-1 and the lower sensing unit third bending beam 3-3 output Y direction rotation feedback signals.

[0051] As shown, Figure 9 As shown, when the six-degree-of-freedom upper platform 1 rotates along the Z direction relative to the lower platform 5, the upper sensing unit first bending beam 2-1 and the upper sensing unit third bending beam 2-3 arranged in the X direction and the upper sensing unit second bending beam 2-2 and the upper sensing unit fourth bending beam 2-4 arranged in the Y direction are bent and deformed about the Z axis and are anti-symmetric about the center of the Z axis, and the corresponding strain gauges on the upper sensing unit first bending beam 2-1, the upper sensing unit second bending beam 2-2, the upper sensing unit third bending beam 2-3 and the upper sensing unit fourth bending beam 2-4 output Z direction rotation feedback signals.

[0052] The six-degree-of-freedom strain sensing device suitable for Stewart platform feedback can realize integrated design of six-degree-of-freedom platform actuation sensing, has compact structure, no motion gap and no mechanical friction, and can realize high-precision feedback control of the six-degree-of-freedom platform.

[0053] Although the present application has been disclosed with the above preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the present application by using the disclosed methods and technical contents without departing from the spirit and scope of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, which does not depart from the technical solutions of the present application, all belong to the protection scope of the technical solutions of the present application.

Claims

1. A six degree of freedom strain sensing device suitable for Stewart platform feedback, characterized in that, The upper platform, the upper sensing unit, the lower sensing unit, the mounting frame, the lower platform, the first piezoelectric actuator, the second piezoelectric actuator, the third piezoelectric actuator, the fourth piezoelectric actuator, the fifth piezoelectric actuator and the sixth piezoelectric actuator; The upper platform is hexagonal in shape and has three equal-length short sides and three equal-length long sides, with the short sides and the long sides arranged in opposite positions; The upper sensing unit is connected with the upper platform; The lower sensing unit passes through the upper sensing unit sleeve and is connected with the upper platform through the upper end of the lower sensing unit sleeve; The mounting frame is composed of an upper annular mounting interface, a mounting frame first leg arranged in a "pin" shape below the annular mounting interface and having an angle of 30° with the vertical direction, a mounting frame second leg and a mounting frame third leg; The mounting frame is connected with the upper sensing unit through the upper end of the annular mounting interface of the mounting frame. The lower platform is hexagonal in shape and has three equal-length short sides and three equal-length long sides, with the short sides and the long sides arranged in opposite positions, and is connected with the mounting frame. The first piezoelectric actuator is composed of a middle piezoelectric rod and two end actuator first flexible hinges and actuator second flexible hinges; the second piezoelectric actuator, the third piezoelectric actuator, the fourth piezoelectric actuator, the fifth piezoelectric actuator and the sixth piezoelectric actuator have the same structure as the first piezoelectric actuator; the first piezoelectric actuator, the second piezoelectric actuator, the third piezoelectric actuator, the fourth piezoelectric actuator, the fifth piezoelectric actuator and the sixth piezoelectric actuator are divided into three pairs and arranged in a "pin" shape below the three equal-length short sides of the upper platform and above the three equal-length short sides of the lower platform, and each pair of piezoelectric actuators is arranged in a "Λ" shape with an angle of 60°. The upper sensing unit includes an upper sensing unit sleeve, an upper sensing unit first curved beam, an upper sensing unit second curved beam, an upper sensing unit third curved beam, an upper sensing unit fourth curved beam, an upper sensing unit first "L" shaped lower mounting interface, an upper sensing unit second "L" shaped lower mounting interface, an upper sensing unit third "L" shaped lower mounting interface and an upper sensing unit fourth "L" shaped lower mounting interface; the upper sensing unit first curved beam, the upper sensing unit second curved beam, the upper sensing unit third curved beam and the upper sensing unit fourth curved beam are arranged in a "cross" shape around the upper sensing unit sleeve; the upper sensing unit first "L" shaped lower mounting interface, the upper sensing unit second "L" shaped lower mounting interface, the upper sensing unit third "L" shaped lower mounting interface and the upper sensing unit fourth "L" shaped lower mounting interface are arranged in a "cross" shape around the upper sensing unit sleeve and have an angle of 45° with the upper sensing unit first curved beam, the upper sensing unit second curved beam, the upper sensing unit third curved beam and the upper sensing unit fourth curved beam.

2. The six-degree-of-freedom strain sensing device for feedback of a Stewart platform according to claim 1, wherein, The upper sensing unit is connected with the upper platform through the upper end of the upper sensing unit first upper mounting interface, the upper end of the upper sensing unit second upper mounting interface, the upper end of the upper sensing unit third upper mounting interface and the upper end of the upper sensing unit fourth upper mounting interface.

3. The six-degree-of-freedom strain sensing device for feedback of a Stewart platform according to claim 1, wherein, The lower end of the first "L" shaped lower mounting interface of the upper sensing unit, the lower end of the second "L" shaped lower mounting interface of the upper sensing unit, the lower end of the third "L" shaped lower mounting interface of the upper sensing unit, the lower end of the fourth "L" shaped lower mounting interface of the upper sensing unit, the lower end of the first lower mounting interface of the lower sensing unit, the lower end of the second lower mounting interface of the lower sensing unit, the lower end of the third lower mounting interface of the lower sensing unit and the lower end of the fourth lower mounting interface of the lower sensing unit are connected through the upper end of the ring-shaped mounting interface of the mounting frame.

4. The six-degree-of-freedom strain sensing device for feedback of a Stewart platform according to claim 1, wherein, The lower platform is connected with the mounting frame through the lower ends of the first leg, the second leg and the third leg of the mounting frame.

5. The six-degree-of-freedom strain sensing device suitable for feedback of a Stewart platform according to claim 1, wherein, The first curved beam of the upper sensing unit comprises a front end upper sensing first mounting interface, a flexible hinge connected with the side of the upper sensing mounting interface and arranged horizontally, a square beam adapter connected with the flexible hinge, an upper sensing unit deformation beam connected with the beam adapter, a H-shaped beam connected with the upper sensing unit deformation beam, an upper sensing unit strain beam connected with the H-shaped beam and the upper sensing unit sleeve, an upper sensing unit first strain gauge adhered to the upper part of the upper sensing unit strain beam and an upper sensing unit second strain gauge adhered to the lower part of the upper sensing unit strain beam.

6. The six-degree-of-freedom strain sensing device suitable for feedback of a Stewart platform according to claim 5, wherein, The second curved beam, the third curved beam and the fourth curved beam of the upper sensing unit are the same in structure as the first curved beam of the upper sensing unit.

7. The six-degree-of-freedom strain sensing device suitable for feedback of a Stewart platform according to claim 1, wherein, The lower sensing unit comprises a lower sensing unit sleeve, a first curved beam of the lower sensing unit, a second curved beam of the lower sensing unit, a third curved beam of the lower sensing unit and a fourth curved beam of the lower sensing unit, and the first curved beam, the second curved beam, the third curved beam and the fourth curved beam of the lower sensing unit are arranged in a "cross" shape around the upper sensing unit sleeve.

8. The six-degree-of-freedom strain sensing device suitable for Stewart platform feedback according to claim 7, wherein, The first curved beam of the lower sensing unit comprises a lower sensing unit strain beam connected with the side of the lower sensing unit sleeve, a first flexible hinge of the lower sensing unit arranged below the front end of the lower sensing unit strain beam, a square flexible hinge adapter arranged below the first flexible hinge of the lower sensing unit, a second flexible hinge of the lower sensing unit arranged below the flexible hinge adapter, a first lower mounting interface of the lower sensing unit arranged below the second flexible hinge of the lower sensing unit, a first strain gauge of the lower sensing unit and a second strain gauge of the lower sensing unit adhered to the root of the lower sensing unit strain beam.

9. The six-degree-of-freedom strain sensing device suitable for Stewart platform feedback according to claim 8, wherein, The second curved beam, the third curved beam and the fourth curved beam of the lower sensing unit are the same in structure as the first curved beam of the lower sensing unit.

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