Force sensor

Abstract

The invention relates to the technical field of robots, and provides a force sensor, which comprises a cylindrical shell with two open ends, a first cover plate, a second cover plate, an elastic body and a strain gauge fixed on the elastic body, the elastic body comprises an annular elastic anchor fixed to the shell, a center table arranged on the inner side of the elastic anchor at intervals, and three cross beams extending from the center table to the shell to be connected to the elastic anchor and distributed in the circumferential direction of the center table at equal intervals. The three vertical beams extend from the center table to the first cover plate to be connected to the elastic anchor piece and are distributed at equal intervals in the circumferential direction of the center table, and the strain gauges comprise the first strain gauges fixed to the cross beams in an attached mode and the second strain gauges fixed to the vertical beams in an attached mode; and each cross beam is perpendicular to each vertical beam. Compared with the prior art, the force sensor is low in process difficulty, small in size and good in decoupling effect, and the accuracy and precision of the sensor can be improved conveniently.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robots, and in particular to a force sensor. BACKGROUND

[0002] At present, a six-dimensional force sensor can measure Fx / Fy / Fz three-dimensional orthogonal force components and Mx / My / Mz three-dimensional orthogonal moment components of a point in space, and is used to detect the force and moment borne by a robot end effector when contacting or grabbing an object, to provide force sensing information for force control and compliance control of the robot, so as to complete some complex and delicate tasks. With the development of robots towards light weight, miniaturization and operation delicacy, a sensor with smaller structure, lighter mass and higher sensitivity needs to be designed.

[0003] In the related art, a three-strain beam structure and a cross beam structure are more common; the three-strain beam structure includes a fixed ring, a center table arranged in the fixed ring at intervals, three main beams and three floating beams connecting the fixed ring and the center table, and twelve strain gauges arranged in the length direction of the three main beams. The cross beam structure includes a fixed ring, a center table arranged in the fixed ring at intervals, four main beams and four floating beams connecting the fixed ring and the center table, and twenty-four strain gauges arranged in the length direction of the four main beams.

[0004] In addition, since the length direction of the main beam of the three-strain beam structure only needs to be arranged with a strain gauge, the three-strain beam structure is more easily miniaturized than the cross beam structure. However, when the structure is small to a certain extent, such as when the diameter of the sensor is less than or equal to 20 mm, as the length of the main beam decreases, and since the upper and lower surfaces and the two side surfaces of the main beam of the three-strain beam structure need to be arranged with strain gauges, the size of the strain gauges will simultaneously limit the height and width of the main beam, resulting in that the deformation of the main beam is very small when the sensor detects the force and moment, the strain that can be perceived on the strain gauge is reduced, and the sensitivity of the sensor is reduced. In addition, due to the reduction in the size of the sensor, the internal space of the sensor is reduced, and the operation space is reduced when the strain gauges are pasted, resulting in that the strain gauge pasting process is difficult.

[0005] Therefore, it is necessary to provide a new force sensor to solve the above technical problems. SUMMARY

[0006] The purpose of the present application is to provide a force sensor with low process difficulty, small size, good decoupling effect, and convenient to improve the accuracy and precision of the sensor.

[0007] In order to achieve the above object, the embodiment of the present application provides a force sensor, which comprises a cylindrical shell with a receiving space and two open ends, a first cover plate and a second cover plate respectively covering the two open ends of the shell, an elastic body received in the receiving space, and a strain gauge fixed to the elastic body, the elastic body comprises an elastic anchor fixed to the shell and in a ring shape, a central platform spaced inside the elastic anchor, three horizontal beams extended from the central platform to the elastic anchor and distributed along the circumference of the central platform at equal intervals, and three vertical beams extended from the central platform to the elastic anchor and distributed along the circumference of the central platform at equal intervals, the strain gauge comprises a first strain gauge fixed to each horizontal beam, and a second strain gauge fixed to each vertical beam; each horizontal beam is arranged perpendicular to each vertical beam.

[0008] Preferably, the adjacent two horizontal beams form an included angle of 120° along the extension line of the length direction thereof; the projection of each vertical beam along the length direction thereof is located between the adjacent two horizontal beams and overlaps with the angle bisector of the included angle between the adjacent two horizontal beams.

[0009] Preferably, the second cover plate is spaced apart from the shell, the surface of the central platform facing the second cover plate is fixed to the second cover plate, the horizontal beam is spaced apart from the second cover plate, the cross section of the horizontal beam perpendicular to the extension direction thereof is rectangular, the horizontal beam comprises a first mounting surface facing the first cover plate, a second mounting surface facing the second cover plate, and a side surface connecting the first mounting surface and the second mounting surface, two first strain gauges are arranged on each horizontal beam, and the two first strain gauges on each horizontal beam are respectively mounted on the first mounting surface and the second mounting surface; two second strain gauges are arranged on each vertical beam; the two second strain gauges on the same vertical beam are parallel to the side surface.

[0010] Preferably, the horizontal beam comprises a first main beam fixed to the central platform and a first floating beam extended from one end of the first main beam away from the central platform, the thickness of the first main beam is greater than the thickness of the first floating beam; the end of the first floating beam away from the first main beam is connected to the elastic anchor; the first mounting surface, the second mounting surface, and the side surface are arranged on the first main beam, and the first strain gauge is fixed to the first main beam.

[0011] Preferably, the vertical beam comprises a second main beam fixed to the central platform and a second floating beam extended from one end of the second main beam away from the central platform towards the first cover plate, the thickness of the second main beam is greater than the thickness of the second floating beam; the end of the second floating beam away from the second main beam is fixed to the elastic anchor; The second main beam has a rectangular cross section along its extending direction, and includes third and fourth mounting surfaces parallel to the side surfaces, and the two second strain gauges on the same vertical beam are arranged on the third and fourth mounting surfaces respectively.

[0012] Preferably, the elastic anchor includes a first fixing ring and a second fixing ring arranged at intervals. The housing includes an inner wall facing the elastic anchor, and the outer periphery of the first fixing ring is attached to the inner wall. Each of the second floating beams is fixed to the first fixing ring at an end away from the second main beam. The surface of the first fixing ring facing the first cover plate is fixed to the first cover plate. The outer periphery of the second fixing ring is fixed to the inner wall, and each of the first floating beams is fixed to the second fixing ring at an end away from the first main beam.

[0013] Preferably, the first fixing ring includes a first fixing ring body and three fixed parts formed by extending inward from the inner periphery of the first fixing ring body at equal intervals. The three fixed parts are connected to the three second floating beams one by one.

[0014] Preferably, the second fixing ring is arranged at intervals with the second cover plate, and the second fixing ring is fixedly connected to the housing by bolts.

[0015] Preferably, the center base includes a center base body in the shape of a hexagon, a positioning hole formed by recessing the center base body from the center position of the side close to the second cover plate to the direction away from the second cover plate, and a plurality of fixing holes formed by recessing the center base body from the side close to the second cover plate to the direction away from the second cover plate. The plurality of fixing holes are uniformly distributed on the outer periphery of the positioning hole. The second cover plate includes a second cover plate body, a boss formed by protruding the second cover plate body toward the side close to the first cover plate, a positioning column formed by protruding the boss toward the side close to the first cover plate, and a plurality of mounting holes formed through the second cover plate body and uniformly distributed with each other. The boss is arranged on the side of the center base body close to the second cover plate, and the positioning column is arranged in the positioning hole. The plurality of mounting holes are arranged opposite to the plurality of fixing holes, and are fixedly connected by a plurality of bolts passing through the plurality of mounting holes and the plurality of fixing holes in sequence.

[0016] Preferably, the center base further includes three connecting parts formed by extending the center base body toward the side close to the housing respectively. The three vertical beams are fixed to the three connecting parts at the ends close to the second cover plate respectively. The three connecting parts and the three cross beams are located on the six outer sides of the center base body respectively.

[0017] Preferably, the first strain gauge and the second strain gauge are both 0.5-1 mm away from the center platform.

[0018] Preferably, the gap height between the second cover plate and the second fixing ring along the axial direction is 1-2 mm.

[0019] Preferably, the elastic body is made of any one of aluminum alloy, magnesium alloy, titanium alloy, stainless steel and polymer material PEEK; the first cover plate, the shell and the second cover plate are all made of any one of aluminum alloy, magnesium alloy, titanium alloy and stainless steel.

[0020] Compared with the related art, the force sensor of the present application has the following advantages: the first cover plate and the second cover plate are arranged at opposite ends of the shell, the elastic body is arranged on the inner circumferential side of the shell, and the strain gauges are arranged on the elastic body; the elastic body comprises an elastic anchor member fixed to the shell and in the form of a ring, a center platform arranged on the inner side of the elastic anchor member, three horizontal beams extending from the center platform towards the shell and connected to the elastic anchor member and arranged equidistantly along the circumference of the center platform, and three vertical beams extending from the center platform towards the first cover plate and connected to the elastic anchor member and arranged equidistantly along the circumference of the center platform; each horizontal beam and each vertical beam are arranged perpendicularly to each other; the length of the horizontal beam and the height of the vertical beam are adjusted to adjust the strain response of the first strain gauge and the second strain gauge respectively, improve the patch precision, and thus improve the accuracy and precision of the sensor; the force sensor form of the horizontal beam and the vertical beam realizes the decoupling of the patch process of the strain gauges on the upper and lower surfaces of the horizontal beam and the side strain gauges of the vertical beam, facilitates the patch process of the small-sized sensor, and reduces the difficulty of the patch process. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor. Figure 1 A perspective structural schematic diagram of the force sensor provided by the embodiment of the present application; Figure 2 An exploded view of the force sensor provided by the embodiment of the present application; Figure 3 A sectional view along the A-A line of the force sensor provided by the embodiment of the present application; Figure 1 Figure 4 A structural schematic diagram of the elastic body of the force sensor provided by the embodiment of the present application;​ Figure 5 Structure diagram of the second cover plate of the force sensor provided by the embodiment of the present application; Figure 6 Structure diagram of the first main beam of the force sensor provided by the embodiment of the present application; Figure 7 Structure diagram of the second cover plate of the force sensor provided by the embodiment of the present application; Figure 1 B-B line section view of the force sensor.

[0022] In the figure, 100, force sensor, 1, first cover plate, 2, shell, 20, containing space, 21, inner wall, 3, second cover plate, 31, second cover plate body, 32, boss, 33, positioning column, 34, mounting hole, 4, elastic body, 41, center platform, 411, center platform body, 412, positioning hole, 413, fixing hole, 414, connecting part, 42, cross beam, 421, first main beam, 4211, first mounting surface, 4212, second mounting surface, 4213, side surface, 422, first floating beam, 43, strain gauge, 431, first strain gauge, 432, second strain gauge, 44, vertical beam, 441, second main beam, 4411, third mounting surface, 4412, fourth mounting surface, 442, second floating beam, 45, elastic anchor, 451, first fixing ring, 4511, first fixing ring body, 4512, fixing part, 452, second fixing ring. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0024] Please refer to Figures 1-6 The embodiment of the present application provides a force sensor 100, which comprises a cylindrical shell 2 with a containing space 20 and open at both ends, a first cover plate 1 and a second cover plate 3 respectively covering the two open ends of the shell 2, an elastic body 4 contained in the containing space 20, and a strain gauge 43 fixed to the elastic body 4. The opposite ends of the elastic body 4 are respectively fixed to the first cover plate 1 and the second cover plate 3. The shell 2 is installed on the first cover plate 1, one end of the elastic body 4 is fixedly installed on the first cover plate 1, the other end of the elastic body 4 is fixedly installed on the second cover plate 3, and elastic support is realized by the elastic body 4. Certain sensor decoupling can be realized by the elastic body 4.

[0025] The elastic body 4 comprises an elastic anchor 45 fixed to the outer shell 2 and in a ring shape, a center platform 41 spaced inside the elastic anchor 45, three horizontal beams 42 extending from the center platform 41 towards the outer shell 2 to be connected to the elastic anchor 45 and distributed equidistantly along the circumference of the center platform 41, and three vertical beams 44 extending from the center platform 41 towards the first cover plate 1 to be connected to the elastic anchor 45 and distributed equidistantly along the circumference of the center platform 41. The strain gauge 43 comprises a first strain gauge 431 fixedly attached to each of the horizontal beams 42, and a second strain gauge 432 fixedly attached to each of the vertical beams 44. Each of the horizontal beams 42 and each of the vertical beams 44 are arranged perpendicular to each other.

[0026] Specifically, by adjusting the length of the horizontal beam 42 and the height of the vertical beam 44, the strain response of the first strain gauge 431 and the second strain gauge 432 is adjusted respectively, the patch precision is improved, and the accuracy and precision of the sensor are improved. Through the force sensor 100 form of the horizontal beam 42 and the vertical beam 44, the patching process of the strain gauges on the upper and lower surfaces of the horizontal beam 42 and the side strain gauges of the vertical beam 44 is decoupled, which is beneficial to the patching process of the small sensor and reduces the difficulty of the patching process. Among them, the horizontal beam 42 is horizontally placed and extends in the horizontal direction, and the first strain gauge 431 is located on the length direction of the upper surface or the lower surface of the horizontal beam 42. The vertical beam 44 is vertically placed and extends in the vertical direction, and the second strain gauge 432 is located on the length direction of the left surface or the right surface of the vertical beam 44.

[0027] As shown in Figure 7 The projection of each of the vertical beams 44 along the length direction is located between two adjacent horizontal beams 42, and the angle bisector of the angle between the two adjacent horizontal beams 42 overlaps. Specifically, each of the vertical beams 44 and the adjacent horizontal beams 42 are distributed at an interval of 60° parallel to the plane on which the center platform 41 is located. Within a plane of 360°, three horizontal beams 42 can realize three-dimensional force sensing detection, and three vertical beams 44 can also realize three-dimensional force sensing detection. In this way, by uniformly distributing three horizontal beams 42 at an angle of 120° and three vertical beams 44 at an angle of 120°, and each vertical beam 44 and the adjacent horizontal beam 42 at an angle of 60°, six-dimensional force sensing detection can be realized.

[0028] The second cover plate 3 is spaced apart from the shell 2, the center platform 41 is fixed to the second cover plate 3 towards the surface of the second cover plate 3, the cross section of the cross beam 42 perpendicular to the extending direction thereof is rectangular, the cross beam 42 comprises a first mounting surface 4211 towards the first cover plate 1, a second mounting surface 4212 towards the second cover plate 3, and a side surface 4213 connecting the first mounting surface 4211 and the second mounting surface 4212, two first strain gauges 431 are arranged on each cross beam 42, and the two first strain gauges 431 on each cross beam 42 are respectively mounted on the first mounting surface 4211 and the second mounting surface 4212; two second strain gauges 432 are arranged on each vertical beam 44; the two second strain gauges 432 on the same vertical beam 44 are parallel to the side surface 4213.

[0029] The cross beam 42 comprises a first main beam 421 fixed to the center platform 41 and a first floating beam 422 extending from one end of the first main beam 421 away from the center platform 41, the thickness of the first main beam 421 is greater than the thickness of the first floating beam 422; one end of the first floating beam 422 away from the first main beam 421 is connected to the elastic anchor 45; the first mounting surface 4211, the second mounting surface 4212 and the side surface 4213 are arranged on the first main beam 421, and the first strain gauges 431 are fixedly arranged on the first main beam 421.

[0030] The vertical beam 44 comprises a second main beam 441 fixed to the center platform 41 and a second floating beam 442 extending from one end of the second main beam 441 away from the center platform 41 towards the first cover plate 1, the thickness of the second main beam 441 is greater than the thickness of the second floating beam 442; one end of the second floating beam 442 away from the second main beam 441 is fixed to the elastic anchor 45.

[0031] The second main beam 441 has a rectangular cross section along the extending direction thereof, the second main beam 441 comprises a third mounting surface 4411 and a fourth mounting surface 4412 parallel to the side surface 4213, and the two second strain gauges 432 on the same vertical beam 44 are arranged on the third mounting surface 4411 and the fourth mounting surface 4412 respectively.

[0032] Specifically, the first mounting surface 4211 and the second mounting surface 4212 are located on the upper and lower surfaces of the cross beam 42, and the third mounting surface 4411 and the fourth mounting surface 4412 are located on the left and right surfaces of the vertical beam 44. By respectively pasting the first strain gauge 431 on the upper and lower surfaces of the first main beam 421 of the three cross beams 42, the strain response of the strain gauges on the three cross beams 42 can be adjusted and optimized by adjusting the length of the three cross beams 42 and the height of the first main beam 421 and the first floating beam 422. The third mounting surface 4411 and the fourth mounting surface 4412 (surfaces parallel to the side surfaces of the cross beam 42) of the three vertical beams 44 are pasted with the second strain gauge 432, and the strain response of the second strain gauge 432 on the three vertical beams 44 can be adjusted and optimized by adjusting the height of the three vertical beams 44 and the width (perpendicular to the direction of the cross beam 42) of the second main beam 441 and the second floating beam 442. When the sensor detects the force Fx (force along the X-axis), Fy (force along the Y-axis), and Mz (moment around the Z-axis), the response is measured by the three vertical beams 44. When the sensor detects the force Fz (force along the Z-axis), Mx (moment around the X-axis), and My (moment around the Y-axis), the response is measured by the three cross beams 42. Through the design of the cross beam 42 and the vertical beam 44 described above, a certain decoupling of the strain response of the sensor can be achieved.

[0033] Optionally, the strain gauge 43 has a total of 12 strain gauges. The upper and lower surfaces of the first main beam 421 of the three cross beams 42 have a total of six surfaces, and one first strain gauge 431 is pasted on each surface, for a total of six first strain gauges 431. The left and right side surfaces of the three vertical beams 44 have a total of six surfaces, and one second strain gauge 432 is pasted on each surface, for a total of six second strain gauges 432. The direction of the strain grid of the first strain gauge 431 is along the length direction of the first main beam 421. In addition, through the force sensor 100 form of the cross beam 42 and the vertical beam 44, the pasting process decoupling of the first strain gauge 431 and the second strain gauge 432 is realized, which is beneficial to the pasting process of the small sensor, reduces the difficulty of the pasting process, and improves the pasting precision, thereby improving the accuracy and precision of the sensor. The strain grid is pasted on the surface of the measured object, which can convert the strain of the object surface into resistance change, and the strain of the object can be calculated by measuring the resistance change.

[0034] The elastic anchor 45 comprises a first fixed ring 451 and a second fixed ring 452 which are spaced apart from each other. The shell 2 comprises an inner wall 21 facing the elastic anchor 45, and the outer periphery of the first fixed ring 451 is attached to the inner wall. Each of the second floating beams 442 is fixed to the first fixed ring 451 at an end away from the second main beam 441. The first fixed ring 451 is fixed to the first cover plate 1 at a surface facing the first cover plate 1. The outer periphery of the second fixed ring 452 is fixed to the inner wall of the shell 2. Each of the first floating beams 422 is fixed to the inner periphery of the second fixed ring 452 at an end away from the first main beam 421. The first fixed ring 451 and the second fixed ring 452 can support the horizontal beams 42 and the vertical beams 44, respectively. The first strain gauge 431 and the second strain gauge 432 can sense the slight deformation of an object to indirectly measure physical quantities such as force, stress, strain, and displacement, thereby improving the accuracy and precision of the sensor.

[0035] The first fixed ring 451 comprises a first fixed ring body 4511 and three fixed portions 4512 which are equally spaced apart and extend inward from the inner periphery of the first fixed ring body 4511. The three fixed portions 4512 are connected to the three second floating beams 442 one by one. The three vertical beams 44 are fixed by the three fixed portions 4512, respectively, so that the vertical beams 44 do not deform and contact the inner wall of the shell 2, and the detection precision of the vertical beams 44 is good. Meanwhile, the fixed portions 4512 can support and fix the vertical beams 44, and improve the support strength of the vertical beams 44.

[0036] The second fixed ring 452 is spaced apart from the second cover plate 3, and the second fixed ring 452 and the shell 2 are fixedly connected by bolts. The first fixed ring 451 and the first cover plate 1 are fixedly connected by bolts. The bolts facilitate the disassembly and assembly of the first fixed ring 451 and the second fixed ring 452 with the first cover plate 1 and the shell 2, respectively. Optionally, the number of bolts is three.

[0037] The center platform 41 comprises a center platform body 411 in hexagonal shape, a positioning hole 412 formed by the center platform body 411 recessed away from the second cover plate 3, and a plurality of fixing holes 413 formed by the center platform body 411 recessed away from the second cover plate 3. The plurality of fixing holes 413 are uniformly distributed on the outer periphery of the positioning hole 412. The second cover plate 3 comprises a second cover plate body 31, a boss 32 formed by the second cover plate body 31 protruding towards the first cover plate 1, a positioning column 33 formed by the boss 32 protruding towards the first cover plate 1, and a plurality of mounting holes 34 formed through the second cover plate body 31 and uniformly distributed. The boss 32 is arranged on the side of the center platform body 411 close to the second cover plate 3, and the positioning column 33 is arranged in the positioning hole 412. The plurality of mounting holes 34 are arranged opposite to the plurality of fixing holes 413, and are fixedly connected by a plurality of bolts sequentially passing through the plurality of mounting holes 34 and the plurality of fixing holes 413. The center platform body 411 is used to mount the cross beam 42 and the vertical beam 44 respectively. The center platform body 411 and the second cover plate 3 are positioned by the positioning hole 412 and the positioning column 33, and are fixedly connected by a plurality of bolts sequentially passing through the plurality of mounting holes 34 and the plurality of fixing holes 413.

[0038] The center platform 41 further comprises three connecting portions 414 formed by the center platform body 411 extending towards the side close to the shell 2 respectively. The three vertical beams 44 are fixed to the three connecting portions 414 respectively at the end close to the second cover plate 3. The three connecting portions 414 and the three cross beams 42 are located on the six outer sides of the center platform body 411 respectively.

[0039] The distance between the first strain gauge 431 and the second strain gauge 432 and the center platform 41 is 0.5-1mm.

[0040] The gap height of the second cover plate 3 and the second fixing ring 452 along the axial direction is 1-2mm. The second cover plate 3 is prevented from abutting against the shell 2 when being strained, and the accuracy and precision of the sensor are improved.

[0041] The elastic body 4 is made of any one of aluminum alloy, magnesium alloy, titanium alloy, stainless steel, and high polymer material PEEK (polyether ether ketone). The elastic body 4 has high structural strength and good elastic performance. The elastic body 4 can also be a non-metallic material, as long as it can produce elastic deformation in the recovery state.

[0042] The first cover plate 1, the shell 2 and the second cover plate 3 are made of any one of aluminum alloy, magnesium alloy, titanium alloy and stainless steel, so that the structural strength of the first cover plate 1, the shell 2 and the second cover plate 3 is high, and meanwhile, production is convenient and cost is saved.

[0043] Compared with the related art, the force sensor of the application has the following advantages: the first cover plate and the second cover plate are arranged at opposite ends of the shell respectively, the elastic body is arranged on the inner circumferential side of the shell, and the strain gauges are arranged on the elastic body; the elastic body comprises an elastic anchor member fixed to the shell and in the form of a ring, a central platform arranged on the inner side of the elastic anchor member, three horizontal beams extending from the central platform to the elastic anchor member and distributed along the circumference of the central platform at equal intervals, and three vertical beams extending from the central platform to the elastic anchor member and distributed along the circumference of the central platform at equal intervals; the strain gauges comprise first strain gauges fixed to each horizontal beam and second strain gauges fixed to each vertical beam; each horizontal beam and each vertical beam are arranged perpendicularly to each other; the length of the horizontal beam and the height of the vertical beam are adjusted to adjust the strain response of the first strain gauges and the second strain gauges respectively, so as to improve the patch precision and the accuracy and precision of the sensor; the force sensor form of the horizontal beam and the vertical beam realizes the decoupling of the patch process of the strain gauges on the upper and lower surfaces of the horizontal beam and the side surfaces of the vertical beam, facilitates the patch process of the small-sized sensor, and reduces the difficulty of the patch process.

[0044] The above only describes the embodiments of the application, and it should be noted that, for those skilled in the art, improvements can be made without departing from the concept of the application, and these improvements are within the protection scope of the application.

Claims

1. A force sensor, comprising a cylindrical outer shell having a receiving space and openings at both ends, a first cover plate and a second cover plate respectively covering the openings at both ends of the outer shell, an elastic body received within the receiving space, and a strain gauge fixed to the elastic body, characterized in that, The elastomer includes an annular elastic anchor fixed to the outer shell, a central platform spaced apart on the inner side of the elastic anchor, three crossbeams extending from the central platform toward the outer shell and connected to the elastic anchor and evenly spaced along the circumference of the central platform, and three vertical beams extending from the central platform toward the first cover plate and connected to the elastic anchor and evenly spaced along the circumference of the central platform. The strain gauges include a first strain gauge fixed to each of the crossbeams and a second strain gauge fixed to each of the vertical beams; each crossbeam and each vertical beam are perpendicular to each other.

2. The force sensor according to claim 1, characterized in that, The extensions of two adjacent crossbeams along their length direction form a 120° angle; the projection of each vertical beam along its length direction lies between two adjacent crossbeams and overlaps with the angle bisector of the angle between two adjacent crossbeams.

3. The force sensor according to claim 2, characterized in that, The second cover plate is spaced apart from the outer shell. The surface of the central platform facing the second cover plate is fixed to the second cover plate. The crossbeam is spaced apart from the second cover plate. The crossbeam has a rectangular cross-section perpendicular to its extension direction. The crossbeam includes a first mounting surface facing the first cover plate, a second mounting surface facing the second cover plate, and a side surface connecting the first mounting surface and the second mounting surface. Each crossbeam is provided with two first strain gauges, which are respectively mounted on the first mounting surface and the second mounting surface. Each vertical beam is provided with two second strain gauges. The two second strain gauges on the same vertical beam are parallel to the side surface.

4. The force sensor according to claim 3, characterized in that, The crossbeam includes a first main beam fixed to the central platform and a first floating beam extending from the end of the first main beam away from the central platform. The thickness of the first main beam is greater than the thickness of the first floating beam. The end of the first floating beam away from the first main beam is connected to the elastic anchor. The first mounting surface, the second mounting surface, and the side surface are provided on the first main beam. The first strain gauge is attached and fixed to the first main beam.

5. The force sensor according to claim 4, characterized in that, The vertical beam includes a second main beam fixed to the central platform and a second floating beam extending from the end of the second main beam away from the central platform toward the first cover plate. The thickness of the second main beam is greater than the thickness of the second floating beam. The end of the second floating beam away from the second main beam is fixed to the elastic anchor. The second main beam has a rectangular cross-section along its extension direction. The second main beam includes a third mounting surface and a fourth mounting surface parallel to the side surface. Two second strain gauges on the same vertical beam are respectively disposed on the third mounting surface and the fourth mounting surface.

6. The force sensor according to claim 5, characterized in that, The elastic anchor includes a first fixing ring and a second fixing ring that are spaced apart from each other. The outer casing includes an inner wall facing the elastic anchor, the outer peripheral side of the first fixing ring is attached to the inner wall, and one end of each second floating beam away from the second main beam is fixed to the first fixing ring; the surface of the first fixing ring facing the first cover plate is fixed to the first cover plate. The outer periphery of the second fixing ring is fixed to the inner wall, and the end of each of the first floating beams away from the first main beam is respectively fixed to the second fixing ring.

7. The force sensor according to claim 6, characterized in that, The first fixing ring includes a first fixing ring body and three equally spaced fixing parts extending inward from the inner circumference of the first fixing ring body; the three fixing parts are connected to the three second floating beams one by one.

8. The force sensor according to claim 6, characterized in that, The second fixing ring is spaced apart from the second cover plate, and the second fixing ring is fixedly connected to the outer shell by bolts.

9. The force sensor according to claim 1, characterized in that, The central platform includes a hexagonal central platform body, a positioning hole formed by recessing the central platform body from the center position on the side near the second cover plate toward the direction away from the second cover plate, and a plurality of fixing holes formed by recessing the central platform body from the side near the second cover plate toward the direction away from the second cover plate; the plurality of fixing holes are evenly spaced on the outer periphery of the positioning hole. The second cover plate includes a second cover plate body, a boss protruding from the second cover plate body towards the side near the first cover plate, a positioning post protruding from the boss towards the side near the first cover plate, and a plurality of mounting holes formed through the second cover plate body and evenly distributed among each other; the boss is disposed on the side of the central platform body near the second cover plate, and the positioning post is disposed in the positioning hole; the plurality of mounting holes and the plurality of fixing holes are arranged opposite to each other, and are fixedly connected by a plurality of bolts passing through the plurality of mounting holes and the plurality of fixing holes in sequence.

10. The force sensor according to claim 9, characterized in that, The central platform also includes three connecting portions formed by the central platform body extending towards one side of the outer shell; one end of the three vertical beams near the second cover plate is fixed to the three connecting portions; wherein the three connecting portions and the three horizontal beams are respectively located on the six outer sides of the central platform body.

11. The force sensor according to claim 1, characterized in that, The distances between the first strain gauge and the second strain gauge and the central stage are both 0.5~1mm.

12. The force sensor according to claim 6, characterized in that, The gap between the second cover plate and the second fixing ring along their axial direction is 1~2mm.

13. The force sensor according to claim 1, characterized in that, The elastomer is made of any one of the following materials: aluminum alloy, magnesium alloy, titanium alloy, stainless steel, and PEEK polymer; the first cover plate, the outer shell, and the second cover plate are all made of any one of the following materials: aluminum alloy, magnesium alloy, titanium alloy, and stainless steel.

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