Multi-dimensional force detection structure

Abstract

The application relates to the technical field of mechanical arms and discloses a multi-dimensional force detection structure, which comprises an outer cylinder, an inner shaft with one end extending into the outer cylinder, and a force detection assembly comprising a first MEMS force sensor, a second MEMS force sensor, a third MEMS force sensor and a fourth MEMS force sensor; the first MEMS force sensor can detect the acting force in a first direction; the second MEMS force sensor can detect the acting force in a second direction; the third MEMS force sensor can detect the acting force in a third direction; and the fourth MEMS force sensor can detect the tangential force when the inner shaft and the outer cylinder rotate in the third direction. The multi-dimensional force detection structure disclosed by the application has high detection precision, strong anti-creep ability and small temperature drift, and overcomes the technical prejudice that the prior art can only use strain gauge type sensors to detect the stress in each direction due to the structural limitation of the multi-dimensional force detection structure.

Description

Technical Field

[0001] This invention relates to the field of robotic arm technology, and in particular to a multidimensional force detection structure. Background Technology

[0002] In the field of modern industrial automation, robotic arms are increasingly widely used, and their performance and precision directly affect production efficiency and product quality. To achieve precise control of the robotic arm, it is necessary to detect the forces acting on it in various directions in real time and accurately. Multi-dimensional force sensing structures, as a key sensing device, can be installed on the robotic arm to detect forces in various directions in real time, providing accurate force feedback information. However, most existing force sensors are strain gauge sensors, which have some problems in practical applications.

[0003] First, strain gauge sensors have relatively low detection accuracy. Since strain gauges work by measuring the deformation of a material under stress to calculate the force, their accuracy is significantly affected by material properties and manufacturing processes. Therefore, it is difficult for these force sensors to achieve high-precision detection of minute forces in practical applications. Second, strain gauge sensors have poor creep resistance. After prolonged stress, the sensitive element of a strain gauge sensor will undergo creep, causing the sensor's output signal to drift and affecting detection accuracy. Finally, strain gauge sensors suffer from temperature drift; it is difficult to eliminate the influence of temperature on the output signal in practical applications, leading to significant detection errors. Summary of the Invention

[0004] Based on the above, the purpose of this invention is to provide a multidimensional force detection structure that solves the problems of low detection accuracy, poor creep resistance and severe temperature drift of existing strain gauge multidimensional force sensors, and greatly promotes the application of multidimensional force sensors in the field of high-precision force control.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A multidimensional force detection structure includes: an outer cylinder; an inner shaft, one end of which extends into the outer cylinder; a support boss on one of the inner wall of the outer cylinder and the outer wall of the inner shaft, and an abutment groove corresponding to the support boss on the other; the support boss can contact the abutment groove, and the contact area is the contact region; the outer cylinder or the inner shaft can rotate a preset angle around any point in the contact region; and a force detection assembly including a first MEMS force sensor, a second MEMS force sensor, a third MEMS force sensor, and a fourth MEMS force sensor, all located between the inner shaft and the outer cylinder, with the third MEMS force sensor located at the end of the inner shaft; the first MEMS force sensor can detect... The first direction of force, the second MEMS force sensor can detect the second direction of force, the third MEMS force sensor can detect the third direction of force, and the fourth MEMS force sensor can detect the tangential force when the inner shaft and the outer cylinder rotate along the third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other; the first MEMS force sensor, the second MEMS force sensor, the third MEMS force sensor and the fourth MEMS force sensor are all chip-type force sensors, the chip-type force sensor includes a top cover plate, a base, a sealing film and a force measuring chip, the sealing film covers the base and the two form a hydraulic cavity, the top cover plate is fixed on the sealing film, and the force measuring chip is disposed on the base and can detect the hydraulic pressure of the liquid in the hydraulic cavity.

[0007] As a preferred embodiment of a multidimensional force detection structure, the supporting boss is disposed on the inner wall of the outer cylinder and includes a first rotating boss and a second rotating boss. A receiving groove is formed between the first rotating boss and the second rotating boss. The abutment groove is disposed on the inner shaft and includes a first abutment sub-groove and a second abutment sub-groove. The first rotating boss extends into the first abutment sub-groove and the bottom ends of the two contact each other to form a first contact sub-region. The second rotating boss extends into the second abutment sub-groove and the bottom ends of the two contact each other to form a second contact sub-region. The first contact sub-region and the second contact sub-region form the contact area.

[0008] As a preferred embodiment of a multidimensional force detection structure, the multidimensional force detection structure further includes a pressure block assembly. Both the pressure block assembly and the fourth MEMS force sensor are disposed within the receiving groove, with one of them fixed to the support boss and the other disposed on the inner shaft. The pressure block assembly includes a first pressure block and a second pressure block. The number of fourth MEMS force sensors is at least two. Both the first pressure block and the second pressure block can abut against at least one of the fourth MEMS force sensors.

[0009] As a preferred embodiment of a multidimensional force detection structure, the base is provided with a liquid protrusion, the chip-type force sensor further includes a pressure ring, the sealing membrane is a metal membrane, the pressure ring is fixed on the metal membrane and positioned directly opposite the liquid protrusion, so that the metal membrane is sandwiched between the pressure ring and the base, the top cover plate is spaced apart from the pressure ring and has an avoidance notch, the metal membrane includes a metal corrugated sheet and a metal flat sheet, the top cover plate is fixed on the metal flat sheet and the top cover plate and the sealing membrane form a deformable gap at the avoidance notch.

[0010] As a preferred embodiment of a multidimensional force detection structure, one of the outer wall of the inner shaft and the inner wall of the outer cylinder is provided with two first mounting grooves, and the other is provided with two third pressure blocks. The two first mounting grooves are distributed on both sides of the inner shaft along the first direction. Each first mounting groove is provided with a first MEMS force sensor, and each first MEMS force sensor corresponds to one of the third pressure blocks.

[0011] As a preferred embodiment of a multidimensional force detection structure, one of the outer wall of the inner shaft and the inner wall of the outer cylinder is provided with two second mounting grooves, and the other is provided with two fourth pressure blocks. The two second mounting grooves are distributed on both sides of the inner shaft along the second direction. Each second mounting groove is provided with a second MEMS force sensor, and each second MEMS force sensor corresponds to one of the fourth pressure blocks.

[0012] As a preferred embodiment of a multidimensional force detection structure, the multidimensional force detection structure further includes a connecting assembly, which includes a connecting cylinder and an axial pressure seat. The connecting cylinder is connected to the outer cylinder, and the axial pressure seat is disposed inside the connecting cylinder and can move relative to the connecting cylinder along the third direction. The connecting cylinder is also provided with a third mounting groove, in which two third MEMS force sensors are disposed. The inner shaft and the axial pressure seat are respectively located on both sides of the two third MEMS force sensors along the third direction.

[0013] As a preferred embodiment of a multidimensional force detection structure, the axial pressure seat is provided with a positioning hole, the connecting cylinder is provided with a positioning groove corresponding to the positioning hole, the connecting assembly further includes a connecting shaft, one end of the connecting shaft is interference-fitted into the positioning hole, and the other end can contact the positioning groove to limit the connecting cylinder, and the connecting cylinder can move axially along the connecting shaft.

[0014] As a preferred embodiment of a multidimensional force detection structure, the supporting boss is a semi-annular boss, the positioning groove is a semi-annular groove, the semi-annular groove is disposed on the outer cylinder, the semi-annular boss is disposed on the inner shaft, and the semi-annular boss and the semi-annular groove form two installation gaps at their two ends along the circumference. Each installation gap contains a fourth MEMS force sensor disposed on the semi-annular boss or the semi-annular groove.

[0015] As a preferred embodiment of a multidimensional force detection structure, the multidimensional force detection structure further includes a rotating column, a connecting arm, a first transmission assembly, a second transmission assembly, and a third transmission assembly. The rotating column is rotatably connected to the connecting arm, and the connecting arm is rotatably connected to the inner shaft or the outer cylinder. The first transmission assembly can drive the rotating column to rotate the connecting arm, the inner shaft, and the outer cylinder along a fourth direction, so that the inner shaft and the outer cylinder move along a second direction and a third direction, wherein the fourth direction is parallel to the axial direction of the rotating column. The second transmission assembly can drive the connecting arm to rotate the inner shaft and the outer cylinder along a fifth direction, so that the inner shaft and the outer cylinder move along the first direction and the third direction, wherein the fifth direction is perpendicular to the fourth direction. The third transmission assembly can drive the inner shaft and the outer cylinder to rotate along the fifth direction, so that the inner shaft and the outer cylinder move along the first direction and the third direction.

[0016] The beneficial effects of this invention are as follows:

[0017] The multidimensional force detection structure disclosed in this invention detects forces in the first direction. Equal and unidirectional forces exist between the inner shaft and outer cylinder, and a first MEMS force sensor detects these forces, thus achieving force detection in the first direction. Similarly, a second MEMS force sensor detects forces in the second direction, and a third MEMS force sensor detects forces in the third direction. Since the lever arm is fixed, the torque in the third direction can be obtained from the tangential force detected by the fourth MEMS force sensor. The hydraulic pressure detected by the force-measuring chip of the chip-type force sensor is the force to be detected. This chip-type force sensor structure features high detection accuracy, strong creep resistance, and low temperature drift, overcoming the technical bias of existing technologies that, due to the structural limitations of multidimensional force detection structures, can only use strain gauge sensors to detect stress in various directions. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the multidimensional force detection structure provided in a specific embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the multi-dimensional force detection structure provided in a specific embodiment of the present invention, excluding the outer cylinder;

[0021] Figure 3 yes Figure 1 Sectional view at AA;

[0022] Figure 4 This is the first cross-sectional view of the chip-type force sensor with a multi-dimensional force detection structure provided in a specific embodiment of the present invention;

[0023] Figure 5 This is a second cross-sectional view of the chip-type force sensor with a multi-dimensional force detection structure provided in a specific embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the axial pressure seat of the multi-dimensional force detection structure provided in a specific embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the connecting cylinder of the multi-dimensional force detection structure provided in a specific embodiment of the present invention;

[0026] Figure 8 yes Figure 1 Remove the section view of the connecting axis at BB.

[0027] In the picture:

[0028] 1. Outer cylinder; 11. Support boss; 111. First rotating boss; 112. Second rotating boss;

[0029] 2. Inner shaft; 20. Abutment groove;

[0030] 31. First MEMS force sensor; 32. Second MEMS force sensor; 33. Third MEMS force sensor; 34. Fourth MEMS force sensor;

[0031] 41. First pressing block; 42. Second pressing block;

[0032] 51. Connecting cylinder; 5101. Third mounting groove; 5102. Positioning groove; 52. Axial pressure seat; 520. Positioning hole;

[0033] 61. Rotating column; 62. Connecting arm; 63. Shoulder joint; 64. Third pivot;

[0034] 71. First transmission assembly; 711. First worm; 712. First worm wheel; 72. Second transmission assembly; 721. Second worm; 722. Second worm wheel; 723. Third worm; 724. Third worm wheel; 73. Third transmission assembly; 731. Fourth worm; 732. Fourth worm wheel;

[0035] 8. Fifth pressing block;

[0036] 10. Hydraulic chamber; 1001. Inner fluid chamber; 1002. Outer fluid chamber; 101. Base; 1010. Connecting hole; 1011. Inner ring boss; 1012. Outer ring boss; 102. Sealing membrane; 103. Connector; 1031. Insulating seat; 1032. Conductive component; 104. Force measuring chip; 105. Inner pressure ring; 106. Outer pressure ring; 107. Top cover plate; 10701. Inner ring clearance groove; 10702. Outer ring clearance groove; 10703. Clearance notch. Detailed Implementation

[0037] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0040] This embodiment provides a multidimensional force detection structure, such as Figures 1 to 8 As shown, the device includes an outer cylinder 1, an inner shaft 2, and a force detection assembly. One end of the inner shaft 2 extends into the outer cylinder 1. A support boss 11 is provided on one of the inner walls of the outer cylinder 1 and the outer wall of the inner shaft 2, while the other has an abutment groove 20 corresponding to the support boss 11. The support boss 11 can contact the abutment groove 20, and the contact area is the contact region. Either the outer cylinder 1 or the inner shaft 2 can rotate a preset angle around any point in the contact region. The force detection assembly includes a first MEMS force sensor 31, a second MEMS force sensor 32, a third MEMS force sensor 33, and a fourth MEMS force sensor 34. MEMS force sensor 31, second MEMS force sensor 32 and fourth MEMS force sensor 34 are all located between inner shaft 2 and outer cylinder 1. Third MEMS force sensor 33 is located at the end of inner shaft 2. First MEMS force sensor 31 can detect force in a first direction, second MEMS force sensor 32 can detect force in a second direction, third MEMS force sensor 33 can detect force in a third direction, and fourth MEMS force sensor 34 can detect tangential force when inner shaft 2 and outer cylinder 1 rotate in a third direction. The first direction, second direction and third direction are perpendicular to each other.

[0041] like Figure 4 and Figure 5 As shown, the first MEMS force sensor, the second MEMS force sensor, the third MEMS force sensor and the fourth MEMS force sensor in this embodiment are all chip-type force sensors. The chip-type force sensor includes a top cover plate 107, a base 101, a sealing film 102 and a force measuring chip 104. The sealing film 102 covers the base 101 and the two form a hydraulic cavity 10. The top cover plate 107 is fixed on the sealing film 102. The force measuring chip 104 is disposed on the base 101 and can detect the hydraulic pressure of the liquid in the hydraulic cavity 10. Specifically, the top cover plate 107 is bonded to the sealing film 102.

[0042] It should be noted that, as Figure 1As shown, in this embodiment, the first direction is the X-axis, the second direction is the Y-axis, and the third direction is the Z-axis, which is the direction of the central axis of the inner shaft 2. A very small gap exists between the outer wall of the inner shaft 2 and the inner wall of the outer cylinder 1, and a lubricant is coated between them to reduce friction. In other embodiments of the invention, a larger gap may exist between the inner shaft 2 and the outer cylinder 1, and this gap may be filled with an elastic buffer. The specific structure of the inner shaft 2 and the outer cylinder 1 is set according to actual needs.

[0043] like Figure 4 and Figure 5 As shown, the chip-type force sensor has a liquid protrusion on its base 101. The chip-type force sensor also includes a pressure ring. The sealing membrane 102 is a metal membrane. The pressure ring is fixed on the metal membrane and is positioned directly opposite the liquid protrusion so that the metal membrane is sandwiched between the pressure ring and the base 101. The top cover plate 107 is spaced apart from the pressure ring and has an avoidance notch 10703. The metal membrane includes a metal corrugated sheet and a metal flat sheet. The top cover plate 107 is fixed on the metal flat sheet and a deformable gap is formed between the top cover plate 107 and the sealing membrane 102 at the avoidance notch 10703. The presence of the deformable gap causes the metal membrane to deform, and the top cover 107 moves in the direction of the force. When the force reaches the preset value, the metal membrane in the deformable gap adheres to the top cover 107, preventing the top cover 107 from moving further. At this time, the metal corrugated sheet of the metal membrane abuts against the end face of the top cover 107. The deformation of the metal corrugated sheet after being pressed increases the contact area between the top cover 107 and the metal membrane, which can reduce the pressure inside the chip-type force sensor and realize the self-protection of the chip-type force sensor.

[0044] like Figure 4 and Figure 5 As shown, the side of the clearance notch 10703 is curved. This design allows the sealing film 102 to fit against the side of the clearance notch 10703, forming a surface contact. This further increases the contact area between the sealing film 102 and the top cover plate 107. In addition, since the side of the clearance notch 10703 is curved, the sealing film 102 makes curved surface contact with the side of the clearance notch 10703 when they fit together, reducing the probability that the sealing film 102 will be punctured due to stress concentration.

[0045] Specifically, such as Figure 4 and Figure 5As shown, the aforementioned liquid boss includes an inner ring boss 1011 and an outer ring boss 1012. The inner ring boss 1011 and the metal membrane form an inner liquid cavity 1001, and the outer ring boss 1012, the inner ring boss 1011, and the metal membrane form an outer liquid cavity 1002. The inner ring boss 1011 is provided with a connecting hole 1010 connecting the inner liquid cavity 1001 and the outer liquid cavity 1002. The inner liquid cavity 1001 and the outer liquid cavity 1002 constitute the aforementioned hydraulic cavity 10. The metal membrane includes a corrugated metal sheet and a flat metal sheet. The top cover plate 107 is fixed on the flat metal sheet. The metal membrane at the top of the outer liquid cavity 1002 is a flat metal sheet, and the metal membrane at the top of the inner liquid cavity 1001 is a corrugated metal sheet. Figure 4 and Figure 5 As shown, the pressure ring in this embodiment includes an inner pressure ring 105 and an outer pressure ring 106. The inner pressure ring 105 is positioned opposite the inner ring boss 1011, and the outer pressure ring 106 is positioned opposite the outer ring boss 1012. Both the inner pressure ring 105 and the outer pressure ring 106 are annular, which securely clamps the metal film between the pressure ring and the liquid boss, ensuring the sealing of the hydraulic chamber 10. The top cover plate 107 in this embodiment is provided with an inner ring clearance groove 1071 and an outer ring clearance groove 10702. The cross-sectional shape of the inner ring clearance groove 10701 is U-shaped, and the cross-sectional shape of the outer ring clearance groove 10702 is L-shaped. The inner pressure ring 105 and at least part of the inner ring boss 1011 extend into the inner ring clearance groove 1071, and the outer pressure ring 106 and at least part of the outer ring boss 1012 extend into the outer ring clearance groove 10702.

[0046] like Figure 5 As shown, the chip-type force sensor in this embodiment also includes a connector 103, which is sealed and fixed on the base 101. A force-measuring chip 104 is fixed on the connector 103 and can detect the hydraulic pressure within the hydraulic chamber 10. The connector 103 includes an insulating base 1031 and a conductive element 1032 fixed on the insulating base 1031. One end of the conductive element 1032 extends out of the insulating base 1031, and the other end is electrically connected to the metal PAD of the force-measuring chip 104. In other embodiments, the connector 103 can also be a conductive stainless steel component. The force-measuring chip 104 is fixed on the connector 103, and the metal PAD of the force-measuring chip 104 contacts the wall surface of the connector 103. The structure and material of the connector 103 can be specifically configured according to actual needs, and this embodiment does not impose specific limitations. In this embodiment, there are four conductive elements 1032 and four metal PADs on the force measuring chip 104. Each of the four metal PADs corresponds to one of the four conductive elements 1032. In other embodiments, the number of conductive elements 1032 and metal PADs on the force measuring chip 104 is not limited to four in this embodiment; they can also be one, two, three, or more than four. Each conductive element 1032 corresponds to one metal PAD on the force measuring chip 104, and the specific number is set according to actual needs.

[0047] The chip-type force sensor provided in this embodiment can detect forces under high-temperature environments. It is small in size, and the base 101 and the metal membrane form an inner liquid cavity 1001 and an outer liquid cavity 1002 that contain and communicate with each other. The outer pressure ring 106 and the inner pressure ring 105 can further achieve a sealed connection between the base 101 and the metal membrane. When the top cover plate 107 is subjected to a force, the force is transmitted through the metal membrane to the liquid in the inner liquid cavity 1001 and the outer liquid cavity 1002, and then acts on the force measuring chip 104 to detect the force. Since the metal membrane is elastic, the linearity of this chip-type force sensor is high. The signal of the force measuring chip 104 is transmitted outward by the conductive element 1032 in the connector 103, realizing the leadless output. It is suitable for environments with strong vibration and large impact. In addition, the overall structure of this chip-type force sensor is cylindrical, which is convenient for installation.

[0048] The multi-dimensional force detection structure provided in this embodiment detects forces in the first direction. There are equal and unidirectional forces between the inner shaft 2 and the outer cylinder 1. The first MEMS force sensor 31 can detect this force, thus realizing the detection of the force in the first direction. Similarly, the second MEMS force sensor 32 can detect forces in the second direction, and the third MEMS force sensor 33 can detect forces in the third direction. Since the lever arm is fixed, the torque in the third direction can be obtained from the tangential force detected by the fourth MEMS force sensor 34. The hydraulic pressure detected by the force measuring chip 104 of the chip-type force sensor is the force to be detected. This chip-type force sensor has the characteristics of high detection accuracy, strong anti-creep capability, and small temperature drift. It overcomes the technical bias of the prior art, which is limited by the structure of the multi-dimensional force detection structure and can only use strain gauge sensors to detect stress in various directions.

[0049] Specifically, such as Figure 3 As shown, in this embodiment, the support boss 11 is disposed on the inner wall of the outer cylinder 1 and includes a first rotating boss 111 and a second rotating boss 112. A receiving groove is formed between the first rotating boss 111 and the second rotating boss 112. The abutment groove 20 is disposed on the outer wall of the inner shaft 2 and includes a first abutment sub-groove and a second abutment sub-groove. The first rotating boss 111 extends into the first abutment sub-groove and the bottom ends of the two contact each other to form a first contact sub-region. The second rotating boss 112 extends into the second abutment sub-groove and the bottom ends of the two contact each other to form a second contact sub-region. The first contact sub-region and the second contact sub-region constitute the above-mentioned contact area.

[0050] It should be noted that in this embodiment, both the first and second contact areas are rectangular areas. When the inner shaft 2 rotates relative to the outer cylinder 1 along the first or second direction, the pivot point between the inner shaft 2 and the outer cylinder 1 is not a point in the actual sense, but rather a linear contact. In other embodiments, the shapes of the first and second contact areas are not limited to the rectangles of this embodiment; they can also be curved surfaces or other shapes. In this case, the pivot point can be linear or point-like, depending on the actual needs.

[0051] Furthermore, the multi-dimensional force detection structure also includes a pressure block assembly. Both the pressure block assembly and the fourth MEMS force sensor 34 are disposed within the receiving groove. One of the pressure block assembly and the fourth MEMS force sensor 34 is fixed to the support boss 11, and the other is disposed on the inner shaft 2. Figure 3 As shown, the pressure block assembly includes a first pressure block 41 and a second pressure block 42, and at least two fourth MEMS force sensors 34. Both the first pressure block 41 and the second pressure block 42 can abut against at least one fourth MEMS force sensor 34. That is, the first pressure block 41 and its corresponding fourth MEMS force sensor 34 are respectively disposed on the support boss 11 and the inner shaft 2, and the second pressure block 42 and its corresponding fourth MEMS force sensor 34 are respectively disposed on the support boss 11 and the inner shaft 2. When the outer cylinder 1 and the inner shaft 2 are subjected to torque along a third direction, either the first pressure block 41 or the second pressure block 42 can abut against its corresponding fourth MEMS force sensor 34. The force detected by the fourth MEMS force sensor 34 is the shear force between the inner shaft 2 and the outer cylinder 1. Since the lever arm can be considered a constant, the torque can be directly calculated.

[0052] In this embodiment, the outer wall of the inner shaft 2 is provided with two first mounting slots, and the inner wall of the outer cylinder 1 is provided with two third pressure blocks. The two first mounting slots are distributed along a first direction on both sides of the inner shaft 2. Each first mounting slot contains a first MEMS force sensor 31, and each first MEMS force sensor 31 corresponds to a third pressure block. In other embodiments, the first mounting slots for mounting the first MEMS force sensors 31 can also be provided on the inner wall of the outer cylinder 1, and the third pressure blocks can be provided on the outer wall of the inner shaft 2, depending on actual needs. The number of first mounting slots and third pressure blocks is not limited to two in this embodiment, but can also be four, depending on actual needs.

[0053] In this embodiment, the outer wall of the inner shaft 2 is provided with two second mounting slots, and the inner wall of the outer cylinder 1 is provided with two fourth pressure blocks. The two second mounting slots are distributed along the second direction on both sides of the inner shaft 2. Each second mounting slot contains a second MEMS force sensor 32, and each second MEMS force sensor 32 corresponds to one fourth pressure block. In other embodiments, the second mounting slots for mounting the second MEMS force sensors 32 can also be provided on the inner wall of the outer cylinder 1, and the fourth pressure blocks can be provided on the outer wall of the inner shaft 2, depending on actual needs. The number of second mounting slots and fourth pressure blocks is not limited to two in this embodiment, but can also be four, depending on actual needs.

[0054] The multidimensional force detection structure in this embodiment also includes connecting components, such as... Figures 6 to 8 As shown, the connecting assembly includes a connecting cylinder 51 and an axial pressure seat 52. The connecting cylinder 51 is connected to the outer cylinder 1. The axial pressure seat 52 is disposed inside the connecting cylinder 51 and can move relative to the connecting cylinder 51 in a third direction. The connecting cylinder 51 is also provided with a third mounting groove 5101, in which two third MEMS force sensors 33 are disposed. The inner shaft 2 and the axial pressure seat 52 are respectively located on both sides of the two third MEMS force sensors 33 in a third direction. Figure 8 As shown, the axial pressure seat 52 is provided with a fifth pressure block 8, and the inner shaft 2 is provided with a sixth pressure block (not shown in the figure). The fifth pressure block 8 corresponds to a third MEMS force sensor 33, and the sixth pressure block corresponds to another third MEMS force sensor 33.

[0055] Specifically, such as Figures 6 to 8 As shown, the axial pressure seat 52 has two positioning holes 520, and the connecting cylinder 51 has two positioning grooves 5102 corresponding to the two positioning holes 520. The connecting assembly also includes two connecting shafts (not shown in the figure). One end of each connecting shaft is interference-fitted into a positioning hole 520, and the other end of each connecting shaft can contact a positioning groove 5102 to limit the connecting cylinder 51. The connecting cylinder 51 can move along the axial direction of the connecting shaft. During installation, firstly, the axial pressure seat 52 is pressed into the connecting cylinder 51 after passing through the third mounting groove 5101 along the axial direction of the connecting cylinder 51. Then, one end of the connecting shaft is inserted into the positioning hole 520 and the axial pressure seat 52 is rotated so that the connecting shaft abuts against the positioning groove 5102 of the connecting cylinder 51 to limit the connecting cylinder 51. Finally, the two third MEMS force sensors 33 are installed in the third mounting groove 5101.

[0056] In non-operating mode, the readings of the two third MEMS force sensors 33 are zero. When a force is applied outward along the axial direction of the axial pressure seat 52 from the axial pressure seat 52 to the inner shaft 2, the axial pressure seat 52 drives the fifth pressure block 8 to press the third MEMS force sensor 33 that is close to it. The reading of the third MEMS force sensor 33 is the force applied outward by the multidimensional force detection structure at this time. When subjected to a force along the axial direction of the axial pressure seat 52 from the inner shaft 2 to the axial pressure seat 52, the inner shaft 2 drives the sixth pressure block to press the third MEMS force sensor 33 that is close to it. The reading of the third MEMS force sensor 33 is the force experienced by the multidimensional force detection structure at this time.

[0057] In other embodiments, the support boss 11 is a semi-annular boss, and the positioning groove 5102 is a semi-annular groove. The semi-annular groove is disposed on the outer cylinder 1, and the semi-annular boss is disposed on the inner shaft 2. The first pressure block 41 and the second pressure block 42 of the pressure block assembly are both disposed at both ends of the semi-annular groove along the circumference. The semi-annular boss and the two ends of the semi-annular groove along the circumference form two installation gaps. Each installation gap contains a fourth MEMS force sensor 34 disposed on the semi-annular boss. The first pressure block 41 and the second pressure block 42 are respectively disposed corresponding to one fourth MEMS force sensor 34. In other embodiments, the first pressure block 41 and the second pressure block 42 can also be disposed at both ends of the semi-annular boss, and the fourth MEMS force sensor 34 can be disposed at both ends of the semi-annular groove, depending on actual needs.

[0058] like Figure 1 and Figure 2 As shown, the multidimensional force detection structure of this embodiment also includes a rotating column 61, a connecting arm 62, a first transmission component 71, a second transmission component 72, and a third transmission component 73. The rotating column 61 and the connecting arm 62 are rotatably connected, and the connecting arm 62 is rotatably connected to the inner shaft 2 or the outer cylinder 1. The first transmission component 71 can drive the rotating column 61 to rotate the connecting arm 62, the inner shaft 2, and the outer cylinder 1 along a fourth direction, so that the inner shaft 2 and the outer cylinder 1 move along a second direction and a third direction, wherein the fourth direction is parallel to the axial direction of the rotating column 61. The second transmission component 72 can drive the connecting arm 62 to rotate the inner shaft 2 and the outer cylinder 1 along a fifth direction, so that the inner shaft 2 and the outer cylinder 1 move along a first direction and a third direction, wherein the fifth direction is perpendicular to the fourth direction. The third transmission component 73 can drive the inner shaft 2 and the outer cylinder 1 to rotate along a fifth direction, so that the inner shaft 2 and the outer cylinder 1 move along a first direction and a third direction.

[0059] Specifically, such as Figure 2As shown, the first transmission assembly 71 includes a first motor (not shown), a first worm 711, and a first worm wheel 712. The first worm wheel 712 is fixed on the rotating column 61 and is meshed with the first worm 711. The first motor can drive the first worm 711 to rotate, and the first worm wheel 712 meshing with the first worm 711 can rotate synchronously, so that the rotating column 61 rotates in the fourth direction.

[0060] like Figure 1 As shown, the multidimensional force detection structure also includes a shoulder joint 63, a first rotating shaft (not shown in the figure), and a second rotating shaft (not shown in the figure). One end of the shoulder joint 63 is rotatably connected to the rotating column 61 via the first rotating shaft, and the other end of the shoulder joint 63 is rotatably connected to the connecting arm 62 via the second rotating shaft. The first rotating shaft drives the outer cylinder 1 and the inner shaft 2 to rotate sequentially through the shoulder joint 63 and the connecting arm 62. The second rotating shaft drives the inner shaft 2 and the outer cylinder 1 to rotate via the connecting arm 62. Figure 2 As shown, the second transmission assembly 72 includes a second motor (not shown), a second worm 721, a second worm wheel 722, a third motor (not shown), a third worm 723, and a third worm wheel 724. The second worm wheel 722 is fixed on the first rotating shaft and meshes with the second worm 721. The third worm wheel 724 is fixed on the second rotating shaft and meshes with the third worm 723. The second motor can drive the second worm 721 to rotate, and the second worm wheel 722 meshing with the second worm 721 drives the first rotating shaft to rotate synchronously. The third motor can drive the third worm 723 to rotate, and the third worm wheel 724 meshing with the third worm 723 drives the second rotating shaft to rotate synchronously.

[0061] like Figure 2 As shown, the third transmission component 73 in this embodiment includes a fourth motor (not shown), a fourth worm 731, and a fourth worm wheel 732. The multi-dimensional force detection structure also includes a third rotating shaft 64. The fourth worm wheel 732 is fixed on the third rotating shaft 64 and meshes with the fourth worm 731. The third rotating shaft 64 can drive the outer cylinder 1 and the inner shaft 2 to rotate. The fourth motor can drive the fourth worm 731 to rotate, causing the fourth worm wheel 732 meshing with the fourth worm 731 to rotate. The fourth worm wheel 732 drives the outer cylinder 1 and the inner shaft 2 to rotate through the third rotating shaft 64.

[0062] It should be noted that, in other embodiments of the present invention, the structures of the first transmission component 71, the second transmission component 72, and the third transmission component 73 are not limited to the motor, worm gear, and worm structure of this embodiment, and can also be other drive structures such as motors and gear sets, depending on actual needs.

[0063] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A multidimensional force detection structure, characterized in that, include: outer cylinder; An inner shaft extends into the outer cylinder at one end. A support boss is provided on one of the inner walls of the outer cylinder and the outer wall of the inner shaft, and an abutment groove corresponding to the support boss is provided on the other. The support boss can contact the abutment groove, and the point of contact is the contact area. The outer cylinder or the inner shaft can rotate a preset angle around any point in the contact area. The support boss is located on the inner wall of the outer cylinder and includes a first rotating boss and a second rotating boss. A receiving groove is formed between the first rotating boss and the second rotating boss. The abutment groove is located on the inner shaft and includes a first abutment sub-groove and a second abutment sub-groove. The first rotating boss extends into the first abutment sub-groove, and their bottom ends contact to form a first contact sub-region. The second rotating boss extends into the second abutment sub-groove, and their bottom ends contact to form a second contact sub-region. The first contact sub-region and the second contact sub-region form the contact area. A force detection component includes a first MEMS force sensor, a second MEMS force sensor, a third MEMS force sensor, and a fourth MEMS force sensor. The first MEMS force sensor, the second MEMS force sensor, and the fourth MEMS force sensor are all located between the inner shaft and the outer cylinder. The third MEMS force sensor is located at the end of the inner shaft. The first MEMS force sensor can detect the force in a first direction, the second MEMS force sensor can detect the force in a second direction, the third MEMS force sensor can detect the force in a third direction, and the fourth MEMS force sensor can detect the tangential force when the inner shaft and the outer cylinder rotate along the third direction. The first direction, the second direction, and the third direction are all perpendicular to each other. The pressure block assembly and the fourth MEMS force sensor are both disposed in the receiving groove, with one of them fixed on the support boss and the other disposed on the inner shaft. The pressure block assembly includes a first pressure block and a second pressure block. The number of fourth MEMS force sensors is at least two. Both the first pressure block and the second pressure block can abut against at least one of the fourth MEMS force sensors. The first MEMS force sensor, the second MEMS force sensor, the third MEMS force sensor, and the fourth MEMS force sensor are all chip-type force sensors. The chip-type force sensor includes a top cover, a base, a sealing film, and a force measuring chip. The sealing film covers the base and the two form a hydraulic cavity. The top cover is fixed on the sealing film. The force measuring chip is disposed on the base and can detect the hydraulic pressure of the liquid in the hydraulic cavity.

2. The multidimensional force detection structure according to claim 1, characterized in that, The base is provided with a liquid protrusion, and the chip-type force sensor also includes a pressure ring. The sealing membrane is a metal membrane. The pressure ring is fixed on the metal membrane and is positioned directly opposite the liquid protrusion, so that the metal membrane is sandwiched between the pressure ring and the base. The top cover plate is spaced apart from the pressure ring and has an avoidance notch. The metal membrane includes a metal corrugated sheet and a metal flat sheet. The top cover plate is fixed on the metal flat sheet, and the top cover plate and the sealing membrane form a deformable gap at the avoidance notch.

3. The multidimensional force detection structure according to claim 1, characterized in that, The outer wall of the inner shaft and the inner wall of the outer cylinder are provided with two first mounting grooves on one of them and two third pressure blocks on the other. The two first mounting grooves are distributed on both sides of the inner shaft along the first direction. Each first mounting groove is provided with a first MEMS force sensor, and each first MEMS force sensor corresponds to one of the third pressure blocks.

4. The multidimensional force detection structure according to claim 1, characterized in that, The outer wall of the inner shaft and the inner wall of the outer cylinder are provided with two second mounting grooves on one of them and two fourth pressure blocks on the other. The two second mounting grooves are distributed on both sides of the inner shaft along the second direction. Each second mounting groove is provided with a second MEMS force sensor, and each second MEMS force sensor corresponds to one of the fourth pressure blocks.

5. The multidimensional force detection structure according to claim 1, characterized in that, The multidimensional force detection structure further includes a connecting assembly, which includes a connecting cylinder and an axial pressure seat. The connecting cylinder is connected to the outer cylinder, and the axial pressure seat is disposed inside the connecting cylinder and can move relative to the connecting cylinder along the third direction. The connecting cylinder is also provided with a third mounting groove, in which two third MEMS force sensors are disposed. The inner shaft and the axial pressure seat are respectively located on both sides of the two third MEMS force sensors along the third direction.

6. The multidimensional force detection structure according to claim 5, characterized in that, The axial pressure seat is provided with a positioning hole, and the connecting cylinder is provided with a positioning groove corresponding to the positioning hole. The connecting assembly also includes a connecting shaft. One end of the connecting shaft is interference-fitted into the positioning hole, and the other end can contact the positioning groove to limit the connecting cylinder. The connecting cylinder can move axially along the connecting shaft.

7. The multidimensional force detection structure according to claim 6, characterized in that, The supporting boss is a semi-annular boss, and the positioning groove is a semi-annular groove. The semi-annular groove is disposed on the outer cylinder, and the semi-annular boss is disposed on the inner shaft. The semi-annular boss and the semi-annular groove form two installation gaps at their two ends along the circumference. Each installation gap contains the fourth MEMS force sensor disposed on the semi-annular boss or the semi-annular groove.

8. The multidimensional force detection structure according to claim 1, characterized in that, The multidimensional force detection structure further includes a rotating column, a connecting arm, a first transmission assembly, a second transmission assembly, and a third transmission assembly. The rotating column is rotatably connected to the connecting arm, and the connecting arm is rotatably connected to the inner shaft or the outer cylinder. The first transmission assembly can drive the rotating column to rotate the connecting arm, the inner shaft, and the outer cylinder along a fourth direction, so that the inner shaft and the outer cylinder move along a second direction and a third direction, wherein the fourth direction is parallel to the axial direction of the rotating column. The second transmission assembly can drive the connecting arm to rotate the inner shaft and the outer cylinder along a fifth direction, so that the inner shaft and the outer cylinder move along the first direction and the third direction, wherein the fifth direction is perpendicular to the fourth direction. The third transmission assembly can drive the inner shaft and the outer cylinder to rotate along the fifth direction, so that the inner shaft and the outer cylinder move along the first direction and the third direction.

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