Miniature six-dimensional force sensor for humanoid robot

Abstract

The utility model discloses a miniature six-dimensional force sensor for a humanoid robot. The miniature six-dimensional force sensor comprises an elastic body which is integrally disc-shaped, and an upper cover plate and a lower cover plate which are arranged at the upper end and the lower end of the elastic body, the elastic body comprises an elastic body hub, a stress table and four strain beams, and the cross section of each strain beam is rectangular; the stress table is hollow and is arranged at the central position of the elastomer hub, the four strain beams are uniformly distributed between the stress table and the elastomer hub, one end of each strain beam is connected with the elastomer hub, and the other end of each strain beam is connected with the stress table; the elastomer hub is provided with a cable outlet. A plurality of strain gauges are adhered to the four strain beams to form six Wheatstone bridges for respectively measuring forces and moments in six directions of Fx, Fy, Fz, Tx, Ty and Tz. The miniature six-dimensional force sensor has the advantages that the thickness of the miniature six-dimensional force sensor is very small, the thickness is only 9.2 mm, the diameter is 45 mm, and the miniature six-dimensional force sensor is suitable for the humanoid robot industry.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of sensor measurement, based on the resistance type strain principle, concretely is a kind of for humanoid robot micro six-dimensional force sensor, for humanoid robot industry. BACKGROUND

[0002] Six-dimensional force sensor is the core component for realizing high-precision force control and dynamic interaction of humanoid robot, is commonly used in hand or wrist, real-time detects the force and torque of grasping object, realizes adaptive gripping, although limited by cost and technical complexity, but with the progress of material innovation and AI algorithm, future will be more intelligent, flexible direction development, promote the scale application of humanoid robot in industry, service field, to adapt to the rapid development of humanoid robot, it is imperative to develop humanoid robot micro six-dimensional force sensor, especially as thin as possible. SUMMARY

[0003] The utility model aims at providing a kind of for humanoid robot micro six-dimensional force sensor, according to the needs of the development of humanoid robot, design and adapt the micro six-dimensional force sensor of humanoid robot, especially as thin as possible.

[0004] The technical method adopted is as follows:

[0005] A kind of for humanoid robot micro six-dimensional force sensor, including the elastic body of whole round disc shape, the upper cover plate and lower cover plate being set in the upper and lower ends of elastic body;The elastic body includes elastic body hub, force receiving platform and four strain beams, the cross section of the strain beam is rectangular;Force receiving platform is hollow, and is placed at the central position of elastic body hub, four strain beams are evenly distributed between force receiving platform and elastic body hub, and one end of strain beam is connected with elastic body hub, and the other end is connected with force receiving platform;Cable outlet is provided on the elastic body hub;The four strain beams paste multiple strain gauges, to form six wheatstone bridges, measure the force and torque of six directions Fx, Fy, Fz, Tx, Ty, Tz respectively.

[0006] Further optimization of the utility model technical scheme, force receiving platform upper end face is 1.7mm higher than elastic body hub upper end face, force receiving platform lower end face is 1.2mm lower than elastic body hub lower end face, leave certain safety space, guarantee six direction measurement accuracy of sensor.

[0007] Further optimization of the utility model technical scheme, the thickness of micro six-dimensional force sensor is 9.2mm, and the diameter is 45mm.

[0008] Further optimization of the technical scheme of the utility model, 28 pieces of strain gauges are pasted on the four strain beams, and are pasted on the four surfaces of the four strain beams respectively. On the upper surface, the lower surface, the left side and the right side of the strain beam, according to the relevant principle in material mechanics, the 28 pieces of strain gauges are pasted on certain positions of the strain beam, which guarantees that the six directions can realize structure decoupling in principle.

[0009] Further optimization of the technical scheme of the utility model, the 28 pieces of strain gauges are R1~R28, wherein, R1~R4 constitute full-bridge measurement Tx, R5~R8 constitute full-bridge measurement Ty, R9~R12 constitute full-bridge measurement Tz, R13~R16 constitute full-bridge measurement Fx, R17~R20 constitute full-bridge measurement Fy, and R21~R28 constitute full-bridge measurement Fz. Other bridge circuits only paste 4 pieces of strain gauges, and 8 pieces of strain gauges are pasted in the Fz direction. The reason why 8 pieces of strain gauges are pasted in the Fz direction is that the measurement error caused by the bending moment Tx or Ty in the Fz direction is reduced, and the measurement accuracy of Fz when eccentric loading is guaranteed.

[0010] Further optimization of the technical scheme of the utility model, the material of the elastic body is stainless steel material, and the stainless steel material selected in the utility model is 17-4 PH. After the stainless steel material is subjected to certain heat treatment process, the yield strength is high, and the overload capacity of the sensor is enhanced.

[0011] Further optimization of the technical scheme of the utility model, the upper cover plate and the lower cover plate are respectively embedded in the grooves on the upper and lower end faces of the elastic body and are fixed, and the periphery is coated with sealing glue; the protection grade of the sensor is guaranteed to reach IP65.

[0012] Further optimization of the technical scheme of the utility model, the inner wall of the elastic body hub is provided with a wire pressing block at the cable outlet port, and a cable groove is arranged on the wire pressing block and communicates with the cable outlet port.

[0013] Further optimization of the technical scheme of the utility model, the cable is led out from the cable outlet port, and the cable outlet port is coated with sealing glue, so that the protection grade of the sensor is also guaranteed to reach IP65.

[0014] Further optimization of the technical scheme of the utility model, the miniature six-dimensional force sensor is an analog output.

[0015] Further optimization of the technical scheme of the utility model.

[0016] Compared with the prior art, the utility model has the beneficial effects that:

[0017] 1. The miniature six-dimensional force sensor for a humanoid robot of the utility model has the most prominent advantage that the thickness of the sensor is very small, the thickness is only 9.2mm, the diameter is 45mm, and the sensor is suitable for the humanoid robot industry.

[0018] 2. The present invention relates to a micro six-dimensional force sensor for humanoid robots. The elastic body is the core component of the sensor. Due to its small spatial volume, a simple four-beam structure is adopted.

[0019] 3. The miniature six-dimensional force sensor for humanoid robots of this invention, after modal analysis of the elastic body using ANSYS Workbench, shows that the natural frequency of the elastic body is 12845Hz, thus exhibiting good dynamic performance.

[0020] 4. The miniature six-dimensional force sensor for humanoid robots of this utility model has been calibrated and has excellent performance, low coupling, and overload exceeding 200%.

[0021] 5. The novel micro six-dimensional force sensor for humanoid robots of this utility model has the advantages of small size, light weight, good dynamic performance, high output sensitivity, and high measurement accuracy. Attached Figure Description

[0022] Figure 1 This is a three-dimensional schematic diagram of the front of a miniature six-dimensional force sensor for a humanoid robot according to this embodiment;

[0023] Figure 2 This is a three-dimensional schematic diagram of the back of a miniature six-dimensional force sensor for a humanoid robot according to this embodiment;

[0024] Figure 3 This is a three-dimensional schematic diagram of an elastomer;

[0025] Figure 4 is a schematic diagram of the bridging principle for a miniature six-dimensional force sensor for a humanoid robot in this embodiment. Figure 4a The upper part is based on the fracture line aa. Figure 4b A mid-section diagram based on fracture lines aa and bb. Figure 4c (The upper view is based on the fracture line bb).

[0026] Figure 5 This is a top view of the elastomeric patch in this embodiment;

[0027] Figure 6 for Figure 5 AA cross-section view;

[0028] Figure 7 for Figure 5 BB cross-section;

[0029] Figure 8 for Figure 5 CC cross-section;

[0030] Figure 9 forFigure 5 DD cross-section;

[0031] Figure 10 This is the equivalent stress cloud diagram calculated by ANSYS Workbench when the loading Fx=1200N is applied to the micro six-dimensional force sensor for the humanoid robot in this embodiment.

[0032] Figure 11 This is the displacement cloud diagram calculated by ANSYS Workbench when the loading Fx=1200N is applied to the micro six-dimensional force sensor for the humanoid robot in this embodiment.

[0033] Figure 12 This is the equivalent stress cloud diagram calculated by ANSYS Workbench when the loading Fy=1200N is applied to the micro six-dimensional force sensor for the humanoid robot in this embodiment.

[0034] Figure 13 This is the displacement cloud map calculated by ANSYS Workbench when the loading Fy=1200N is applied to the micro six-dimensional force sensor for the humanoid robot in this embodiment.

[0035] Figure 14 This is the equivalent stress cloud diagram calculated by ANSYS Workbench when the loading Fz=2000N is applied to the micro six-dimensional force sensor for humanoid robots in this embodiment.

[0036] Figure 15 This is the displacement cloud diagram calculated by ANSYS Workbench when the loading Fz=2000N is applied to the micro six-dimensional force sensor for the humanoid robot in this embodiment.

[0037] Figure 16 This is the equivalent stress cloud diagram calculated by ANSYS Workbench when the loading Tx=27Nm is used for the micro six-dimensional force sensor of the humanoid robot in this embodiment;

[0038] Figure 17 This is the displacement cloud diagram calculated by ANSYS Workbench when the loading Tx=27Nm is applied to the micro six-dimensional force sensor for the humanoid robot in this embodiment;

[0039] Figure 18 This is the equivalent stress cloud diagram calculated by ANSYS Workbench when the loading Ty=27Nm is used for the micro six-dimensional force sensor of the humanoid robot in this embodiment;

[0040] Figure 19 This is the displacement cloud map calculated by ANSYS Workbench when the loading Ty=27Nm is applied to the micro six-dimensional force sensor for the humanoid robot in this embodiment;

[0041] Figure 20 is the equivalent stress nephogram of the human-shaped robot micro six-dimensional force sensor of the embodiment when a load Tz=27Nm is applied, calculated by ANSYS Workbench;

[0042] Figure 21 is the displacement nephogram of the human-shaped robot micro six-dimensional force sensor of the embodiment when a load Tz=27Nm is applied, calculated by ANSYS Workbench;

[0043] Figure 22 is a structural schematic view of the strain gauge;

[0044] wherein 1 is an upper cover plate, 2 is an elastic body, 3 is a lower cover plate, 4 is a first strain beam, 5 is a second strain beam, 6 is a third strain beam, 7 is a fourth strain beam, and R1-R28 are strain gauges. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the utility model more clearly and clearly, the following will be combined with the accompanying drawings to further describe the utility model. It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model. In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as they do not conflict with each other. Figure 1 - the accompanying drawings Figure 22 and embodiments, the utility model will be further described in detail. It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model. In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0046] As shown in Figure 1 and 2 , the embodiment is a micro six-dimensional force sensor for human-shaped robot, which is used in human-shaped robot industry. The micro six-dimensional force sensor for human-shaped robot is based on the principle of resistance strain.

[0047] The micro six-dimensional force sensor for human-shaped robot comprises an upper cover plate 1, an elastic body 2 and a lower cover plate 3, three components.

[0048] The most prominent advantage of the micro six-dimensional force sensor of the embodiment is that the thickness of the sensor is very small, only 9.2mm, and the diameter is 45mm, which is suitable for human-shaped robot industry. The second is that the elastic body 2 is the core component of the sensor, and due to the small space volume, a simple 4-beam structure is adopted. The third is that the modal analysis of the elastic body is carried out by ANSYS Workbench, and the natural frequency of the elastic body is 12845Hz, so it has good dynamic performance. The fourth is that the performance of the micro six-dimensional force sensor of the embodiment is good, the coupling is small, and the overload is more than 200%. The micro six-dimensional force sensor has the advantages of small size, light weight, good dynamic performance and high measurement accuracy.

[0049] As shown in Figure 3As shown, the three-dimensional model of the core component elastomer 2 is shown. The upper cover plate 1 is connected to the elastomer 2 with screws, and the lower cover plate 3 is connected to the elastomer 2 with screws. The perimeter is sealed with glue. The cable exits through the cable outlet and is sealed with glue to ensure that the sensor's protection level reaches IP65.

[0050] like Figure 1 and 2 As shown, grooves are provided on the upper and lower end faces of the elastomer 2, and the upper cover plate 1 and the lower cover plate 3 are respectively embedded in the grooves and fixed with bolts. The periphery is coated with sealant.

[0051] like Figure 3 As shown, the elastic body 2 includes an elastic body hub, a force-bearing platform, and four strain beams. The cross-section of the strain beams is rectangular. The force-bearing platform is hollow and is placed at the center of the elastic body hub. The four strain beams are evenly distributed between the force-bearing platform and the elastic body hub. One end of each strain beam is connected to the elastic body hub, and the other end is connected to the force-bearing platform. A cable outlet 21 is provided on the elastic body hub.

[0052] In this embodiment, the upper surface of the force-bearing platform of the elastomer 2 is 1.7 mm higher than the upper surface of the elastomer hub, and the lower surface of the force-bearing platform is 1.2 mm lower than the lower surface of the elastomer hub.

[0053] In this embodiment, the elastomer 2 is made of stainless steel, 17-4PH, heat-treated, with a hardness of HRC38-40 and a yield strength of not less than 1300 MPa. Sensors all have overload capacity requirements; when the full-scale load Tx / Ty = 27 Nm, the equivalent stress is 513 MPa. To meet the requirement of sensor overload capacity ≥ 200%,...

[0054] In this embodiment, as Figure 3 As shown, a wire clamping block 22 is provided on the inner wall of the elastic body hub of the elastic body 2 at the cable outlet 21. A cable groove is provided on the wire clamping block 22, which communicates with the cable outlet 21. The cable inside the elastic body 2 is placed on the cable groove on the wire clamping block 22. Specifically:

[0055] A cable clamping block 22 is installed on the inner wall of the elastomer hub at the cable outlet 21. A cable clamping plate is installed on the cable clamping block 22 and fixed with two M1.6 screws to fix the cable in the cable groove and prevent it from moving. The cable exits from the cable outlet 21 and is first fixed by the cable clamping block 22 and the cable clamping plate before being sealed with sealant.

[0056] like Figure 5 As shown, four strain beams are symmetrically arranged on the elastic body 2, namely the first strain beam 4, the second strain beam 5, the third strain beam 6, and the fourth strain beam 7. One end of each strain beam is connected to the central force-bearing platform, and the other end is connected to the hub of the elastic body.

[0057] likeFigure 5 As shown in the figure, 28 pieces of strain gauges are pasted on the four strain beams, respectively on the four faces of the four strain beams, to form six Wheatstone bridges for measuring forces and moments in the six directions of Fx, Fy, Fz, Tx, Ty and Tz.

[0058] As shown in FIG. 4, the six measurement directions of Fx, Fy, Fz, Tx, Ty and Tz adopt a full-bridge measurement scheme, in which bridge 1 measures Tx, bridge 2 measures Ty, bridge 3 measures Tz, bridge 4 measures Fx, bridge 5 measures Fy, and bridge 6 measures Fz.

[0059] As shown in the figure, the 28 pieces of strain gauges are R1-R28, in which R1-R4 form a full bridge to measure Tx, R5-R8 form a full bridge to measure Ty, R9-R12 form a full bridge to measure Tz, R13-R16 form a full bridge to measure Fx, R17-R20 form a full bridge to measure Fy, and R21-R28 form a full bridge to measure Fz. Figure 5 As shown in the figure, the 28 pieces of strain gauges are R1-R28, in which R1-R4 form a full bridge to measure Tx, R5-R8 form a full bridge to measure Ty, R9-R12 form a full bridge to measure Tz, R13-R16 form a full bridge to measure Fx, R17-R20 form a full bridge to measure Fy, and R21-R28 form a full bridge to measure Fz.

[0060] Figure 22 As shown in the figure, the 28 pieces of strain gauges are R1-R28, in which R1-R4 form a full bridge to measure Tx, R5-R8 form a full bridge to measure Ty, R9-R12 form a full bridge to measure Tz, R13-R16 form a full bridge to measure Fx, R17-R20 form a full bridge to measure Fy, and R21-R28 form a full bridge to measure Fz.

[0061] As shown in FIG. 4, bridge 1 measures Tx, bridge 2 measures Ty, bridge 3 measures Tz, bridge 4 measures Fx, bridge 5 measures Fy, and bridge 6 measures Fz. The six bridges are connected in parallel, and in the bridge diagram of FIG. 4, R1-R28 represent the strain gauges, and R represents the resistance value of the selected strain gauge, which is 350Ω.

[0062] The micro six-dimensional force sensor for humanoid robots in this embodiment has a range of Fx=Fy=1200N; Fz=2000N; Tx=Ty=Tz=27Nm.

[0063] The pasting positions of the 28 pieces of strain gauges in the micro six-dimensional force sensor for humanoid robots in this embodiment are as follows:

[0064] As shown in FIG. 4, the four strain beams are defined as first strain beam 4, second strain beam 5, third strain beam 6 and fourth strain beam 7, and the first strain beam 4 and the third strain beam 6 are located on the same straight line, and the second strain beam 5 and the fourth strain beam 7 are located on the same straight line.

[0065] ​On the left and right sides of the first strain beam 4, strain gauges R13 and R14 are pasted near the end of the elastic body hub, the strain gauges R13 and R14 are arranged symmetrically along the Y axis, and the welding points of the strain gauges R13 and R14 are directed to the force table direction, that is, the -Y direction; on the left and right sides of the third strain beam 6, strain gauges R15 and R16 are pasted near the end of the elastic body hub, and the strain gauges R15 and R16 are also arranged symmetrically along the Y axis, and the welding points of the strain gauges R15 and R16 are directed to the force table direction, that is, the +Y direction; the strain gauges R14 and R15 are arranged symmetrically along the X axis, and the strain gauges R13 and R16 are also arranged symmetrically along the X axis; through ANSYS Workbench calculation, the wire grid positioning mark distance L1 of the two strain gauges R14 and R15 is 31.2 mm, and the wire grid positioning mark distance of the two strain gauges R13 and R16 is also 31.2 mm. As shown in Figure 6 、 7 and 8.

[0066] On the left and right sides of the first strain beam 4, strain gauges R13 and R14 are pasted near the end of the elastic body hub, the strain gauges R13 and R14 are arranged symmetrically along the Y axis, and the welding points of the strain gauges R13 and R14 are directed to the force table direction, that is, the -Y direction; on the left and right sides of the third strain beam 6, strain gauges R15 and R16 are pasted near the end of the elastic body hub, and the strain gauges R15 and R16 are also arranged symmetrically along the Y axis, and the welding points of the strain gauges R15 and R16 are directed to the force table direction, that is, the +Y direction; the strain gauges R14 and R15 are arranged symmetrically along the X axis, and the strain gauges R13 and R16 are also arranged symmetrically along the X axis; through ANSYS Workbench calculation, the wire grid positioning mark distance L1 of the two strain gauges R14 and R15 is 31.2 mm, and the wire grid positioning mark distance of the two strain gauges R13 and R16 is also 31.2 mm. As shown in Figure 5 、 6 and 7.

[0067] On the left and right sides of the first strain beam 4, strain gauges R13 and R14 are pasted near the end of the elastic body hub, the strain gauges R13 and R14 are arranged symmetrically along the Y axis, and the welding points of the strain gauges R13 and R14 are directed to the force table direction, that is, the -Y direction; on the left and right sides of the third strain beam 6, strain gauges R15 and R16 are pasted near the end of the elastic body hub, and the strain gauges R15 and R16 are also arranged symmetrically along the Y axis, and the welding points of the strain gauges R15 and R16 are directed to the force table direction, that is, the +Y direction; the strain gauges R14 and R15 are arranged symmetrically along the X axis, and the strain gauges R13 and R16 are also arranged symmetrically along the X axis; through ANSYS Workbench calculation, the wire grid positioning mark distance L1 of the two strain gauges R14 and R15 is 31.2 mm, and the wire grid positioning mark distance of the two strain gauges R13 and R16 is also 31.2 mm. As shown in Figure 5 、 6 and 7.

[0068] On the upper and lower surfaces of the first strain beam 4, strain gauges R21 and R22 are pasted near one end of the force platform, and the strain gauges R21 and R22 are symmetrically arranged upward and downward, and the welding points of the strain gauges R21 and R22 are away from the direction of the force platform, that is, the +Y direction; on the upper and lower surfaces of the third strain beam 6, strain gauges R23 and R24 are pasted near one end of the force platform, and the strain gauges R23 and R24 are also symmetrically arranged upward and downward, and the welding points of the strain gauges R23 and R24 are away from the direction of the force platform, that is, the -Y direction; the strain gauges R21 and R24 are symmetric about the X axis, and the strain gauges R22 and R23 are also symmetric about the X axis; through ANSYS Workbench calculation, the wire grid positioning mark distance of the two strain gauges R21 and R24 is 23.8mm, and the wire grid positioning mark distance of the two strain gauges R22 and R23 is also 23.8mm. As shown in Figure 5 、 6 and 7.

[0069] On the left and right sides of the second strain beam 5, strain gauges R17 and R18 are pasted near one end of the elastic body hub, and the strain gauges R17 and R18 are symmetric about the X axis, and the welding points of the strain gauges R17 and R18 are toward the direction of the force platform, that is, the -X direction; on the left and right sides of the fourth strain beam 7, strain gauges R19 and R20 are pasted near one end of the elastic body hub, and the strain gauges R19 and R20 are also symmetric about the X axis, and the welding points of the strain gauges R19 and R20 are toward the direction of the force platform, that is, the +X direction; the strain gauges R18 and R19 are symmetric about the Y axis, and the strain gauges R17 and R20 are also symmetric about the Y axis; through ANSYS Workbench calculation, the wire grid positioning mark distance L3 of the two strain gauges R18 and R19 is 31.2mm, and the wire grid positioning mark distance of the two strain gauges R17 and R20 is also 31.2mm. As shown in Figure 5 、 8 and 9.

[0070] On the upper and lower surfaces of the second strain beam 5, strain gauges R7 and R8 are pasted near one end of the elastic body hub, and the strain gauges R7 and R8 are symmetrically arranged upward and downward, and the welding points of the strain gauges R7 and R8 are toward the direction of the force platform, that is, the -X direction; on the upper and lower surfaces of the fourth strain beam 7, strain gauges R5 and R6 are pasted near one end of the elastic body hub, and the strain gauges R5 and R6 are also symmetrically arranged upward and downward, and the welding points of the strain gauges R5 and R6 are toward the direction of the force platform, that is, the +X direction; the strain gauges R8 and R6 are symmetric about the Y axis, and the strain gauges R7 and R5 are also symmetric about the Y axis, and through ANSYS Workbench calculation, the wire grid positioning mark distance of the two strain gauges R8 and R6 is 31.2mm, and the wire grid positioning mark distance of the two strain gauges R7 and R5 is also 31.2mm. As shown in Figure 5 、 8 and 9.

[0071] The strain gauges R27 and R28 are pasted on the upper and lower surfaces of the second strain beam 5 near one end of the force receiving platform, and the strain gauges R27 and R28 are symmetrically arranged upward and downward, and the welding points of the strain gauges R27 and R28 are away from the force receiving platform, that is, in the +X direction. The strain gauges R25 and R26 are pasted on the upper and lower surfaces of the fourth strain beam 7 near one end of the force receiving platform, and the strain gauges R25 and R26 are also symmetrically arranged upward and downward, and the welding points of the strain gauges R25 and R26 are away from the force receiving platform, that is, in the -X direction. The strain gauges R28 and R25 are symmetrically arranged along the Y axis, and the strain gauges R27 and R26 are also symmetrically arranged along the Y axis. Through ANSYS Workbench calculation, the distance between the wire grids of the strain gauges R28 and R25 is 23.8 mm, and the distance between the wire grids of the strain gauges R27 and R26 is also 23.8 mm. As shown in Figure 5 、 8 and 9.

[0072] The micro six-dimensional force sensor for a humanoid robot in the embodiment is shown in Figure 6 、 7 , 8 and 9, and all the strain gauges pasted on the side surfaces of the four strain beams have a distance L4 of 5.45 mm from the force receiving platform.

[0073] The micro six-dimensional force sensor for a humanoid robot in the embodiment is subjected to modal analysis of the elastic body by ANSYS Workbench, and the natural frequency of the micro six-dimensional force sensor for a humanoid robot is 12845 Hz, which has good dynamic performance.

[0074] The specific strength analysis process of the elastic body by ANSYS Workbench is as follows:

[0075] As described above, the six measurement directions Fx, Fy, Fz, Tx, Ty and Tz adopt the measurement scheme of six Wheatstone bridges, and the simulation calculation is performed by ANSYS Workbench. Each direction is separately subjected to full-scale loading, and the strength and output sensitivity of each direction under full-scale loading are calculated. The material is stainless steel 17-4PH. When calculating the bridge sensitivity, the bridge excitation voltage is calculated as 5V.

[0076] When Fx=1200N is loaded; as shown in Figure 10 and 11 ;

[0077] The first strain beam 4 and the third strain beam 6 are bent, as shown in Figure 5 、 6and 7, strain gauges R13 and R14 are pasted on the side of the first strain beam 4, and strain gauges R15 and R16 are pasted on the side of the third strain beam 6, wherein the strain gauges R13 and R16 are subjected to tensile strain, and the strain gauges R14 and R15 are subjected to compressive strain, forming bridge four as in Fig. 4. Through ANSYS Workbench calculation, the equivalent stress is 62.212 Mpa, the deformation is 0.0033353 mm, the strain measured by R13 is , the strain measured by R14 is , the strain measured by R15 is , and the strain measured by R16 is , then:

[0078]

[0079] represents the output voltage value in the Fx direction when the full scale of Fx is loaded;

[0080] represents the sensitivity coefficient of the strain gauge, and the average value is usually taken, and k = 2 is taken;

[0081] represents the strain measured by the strain gauge R13 in the pasted area;

[0082] represents the strain measured by the strain gauge R14 in the pasted area;

[0083] represents the strain measured by the strain gauge R15 in the pasted area;

[0084] represents the strain measured by the strain gauge R16 in the pasted area;

[0085] represents the excitation voltage of the bridge, and here V = 5V is taken;

[0086]

[0087] then the output sensitivity in the Fx direction is:

[0088] When Fy = 1200N is loaded, as shown in Figure 12 and 13 ;

[0089] The second strain beam 5 and the fourth strain beam 7 are bent, as shown in Figure 5 , 8As shown in Figure 9, strain gauges R17 and R18 are attached to the side of the second strain beam 5, and strain gauges R19 and R20 are attached to the side of the fourth strain beam 7. Strain gauges R17 and R20 are subjected to tensile strain, while strain gauges R19 and R20 are subjected to compressive strain, forming bridge circuit five as shown in Figure 4. ANSYS Workbench calculations show an equivalent stress of 63.69 MPa and a deformation of 0.0039524 mm. The strain measured at R17 is... The dependent variable measured by R18 is The dependent variable measured by R19 is The dependent variable measured by R20 is ,but:

[0090]

[0091] —This indicates the output voltage value in the Fy direction when Fy is fully loaded;

[0092] — This represents the sensitivity coefficient of the strain gauge. In calculations, the average value is usually taken, with k=2.

[0093] —This represents the strain measured in the R17 patch area of ​​the strain gauge;

[0094] —This represents the strain measured in the R18 patch area of ​​the strain gauge;

[0095] —This represents the strain measured in the R19 patch area of ​​the strain gauge;

[0096] —This represents the strain measured in the R20 strain gauge patch area;

[0097] —This represents the excitation voltage of the bridge circuit, which is taken here.

[0098] The output sensitivity in the Fy direction is: The sensitivity is:

[0099] When loading Fz=2000N, such as Figure 14 and 15 As shown;

[0100] All four strain beams bent, such as Figure 5 , 6, 7, 8 and 9, strain gauges R21 and R22 are pasted on the upper side and the lower side of the first strain beam 4 respectively, strain gauges R24 and R23 are pasted on the upper side and the lower side of the third strain beam 6 respectively, strain gauges R25 and R26 are pasted on the upper side and the lower side of the fourth strain beam 7 respectively, and strain gauges R28 and R27 are pasted on the upper side and the lower side of the second strain beam 5 respectively, wherein R21, R24, R25 and R28 are subjected to tensile strain, and R22, R23, R26 and R27 are subjected to compressive strain, and the bridge circuit is VI in FIG. 4. After ANSYS Workbench calculation, the equivalent stress is 238.62 Mpa, the deformation is 0.020561 mm, the measured strain of R21 is , the measured strain of R22 is , the measured strain of R23 is , the measured strain of R24 is , the measured strain of R25 is , the measured strain of R26 is , the measured strain of R27 is , and the measured strain of R28 is , then:

[0101]

[0102] represents the output voltage value in the direction of Fz when Fz is fully loaded;

[0103] represents the sensitivity coefficient of the strain gauge, and the average value is usually taken in calculation, and k=2 is taken;

[0104] represents the measured strain of the strain gauge R21;

[0105] represents the measured strain of the strain gauge R22;

[0106] represents the measured strain of the strain gauge R23;

[0107] represents the measured strain of the strain gauge R24;

[0108] represents the measured strain of the strain gauge R25;

[0109] represents the measured strain of the strain gauge R26;

[0110] — represents the strain value measured by the strain gauge R27 in the patch area;

[0111] — represents the strain value measured by the strain gauge R28 in the patch area;

[0112] — represents the excitation voltage of the bridge, here

[0113] The output sensitivity in the Fz direction is:

[0114] When Tx = 27 Nm is loaded, as shown in Figure 16 and 17 ;

[0115] The first strain beam 4 and the third strain beam 6 are bent, as shown in Figure 5 , 6 and 7, the strain gauges R1 and R2 are pasted on the lower side and the upper side of the first strain beam 4, and the strain gauges R13 and R4 are pasted on the lower side and the upper side of the third strain beam 6, wherein the strain gauges R1 and R4 are subjected to tensile strain, and the strain gauges R2 and R3 are subjected to compressive strain, which constitute bridge one as shown in FIG. 4. Through ANSYS Workbench calculation, the equivalent stress is 457.44 Mpa, the deformation amount is 0.026347 mm, the strain value measured by the strain gauge R1 is , the strain value measured by the strain gauge R2 is , the strain value measured by the strain gauge R3 is , and the strain value measured by the strain gauge R4 is , then:

[0116]

[0117] — represents the output voltage value in the Tx direction when the Tx is full-scale loaded;

[0118] — represents the sensitivity coefficient of the strain gauge, which is usually taken as an average value, and k = 2 is taken;

[0119] — represents the strain value measured by the strain gauge R1 in the patch area;

[0120] — represents the strain value measured by the strain gauge R2 in the patch area;

[0121] — represents the strain value measured by the strain gauge R3 in the patch area;

[0122] — represents the strain value measured by the strain gauge R4 in the patch area;

[0123] — represents the excitation voltage of the bridge, here take

[0124] Then the output sensitivity of Tx direction is:

[0125] Load Ty=27Nm, as shown in Figure 18 and 19 ;

[0126] The fourth strain beam 7 and the second strain beam 5 are bent, as shown in Figure 5 , 8 and 9, strain gauges R5 and R6 are pasted on the lower side and the upper side of the fourth strain beam 7, and strain gauges R7 and R8 are pasted on the lower side and the upper side of the second strain beam 5, wherein the strain gauges R5 and R8 are subjected to tensile strain, and the strain gauges R6 and R7 are subjected to compressive strain, which constitute bridge two as shown in FIG. 4. Through ANSYS Workbench calculation, the equivalent stress is 513.09Mpa, the deformation amount is 0.026721mm, the strain amount measured by R5 is , the strain amount measured by R6 is , the strain amount measured by R7 is , and the strain amount measured by R8 is , then:

[0127]

[0128] — represents the output voltage value of Ty direction when Ty is full-scale loaded;

[0129] — represents the sensitivity coefficient of the strain gauge, usually take the average value, take k=2;

[0130] — represents the strain amount measured by the strain gauge R5 patch area;

[0131] — represents the strain amount measured by the strain gauge R6 patch area;

[0132] — represents the strain amount measured by the strain gauge R7 patch area;

[0133] — represents the strain amount measured by the strain gauge R8 patch area;

[0134] — represents the excitation voltage of the bridge, here take

[0135] Then the output sensitivity of Ty direction is:

[0136] Load Tz=27Nm, as shown in Figure 20 and 21 ;

[0137] Four strain beams are bent, as shown in Figure 5 , 6 , 7, 8 and 9, strain gauges R9 and R10 are respectively pasted on the side of the first strain beam 4, strain gauges R11 and R12 are respectively pasted on the side of the third strain beam 6, wherein strain gauges R9 and R12 are subjected to tensile strain, strain gauges R10 and R11 are subjected to compressive strain, and the bridge circuit three is composed as shown in Fig. 4. Through ANSYS Workbench calculation, the equivalent stress is 234.71Mpa, the deformation is 0.010398mm, the strain measured by R9 is , the strain measured by R10 is , the strain measured by R11 is , and the strain measured by R12 is , then:

[0138]

[0139] — represents the output voltage value in the direction of Tz when Tz is fully loaded;

[0140] — represents the sensitivity coefficient of the strain gauge, usually take the average value, take k=2;

[0141] — represents the strain measured by the strain gauge R9 in the pasted area;

[0142] — represents the strain measured by the strain gauge R10 in the pasted area;

[0143] — represents the strain measured by the strain gauge R11 in the pasted area;

[0144] — represents the strain measured by the strain gauge R12 in the pasted area;

[0145] — represents the excitation voltage of the bridge circuit, here take

[0146] , then the output sensitivity in the direction of Ty is:

[0147] The micro six-dimensional force sensor for a humanoid robot in the embodiment has the advantages of small volume, light weight, good dynamic performance, high measurement accuracy and the like.

[0148] The micro six-dimensional force sensor for a humanoid robot in the embodiment is externally connected with a data collector of model NST2000 developed by Nanjing Shenyuan Life Intelligence Technology Co., Ltd., UDP communication is performed, the sensor is calibrated according to the Multi-component force sensor calibration specification (standard number: JJF 1560-2016), and the calibration calculation results are shown in Table 1 below.

[0149] Table 1

[0150]

[0151] In summary, according to the calibration data in Table 1, it is shown that the micro six-dimensional force sensor for a humanoid robot in the embodiment has high precision and good performance, and is suitable for use in the robot industry.

[0152] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the utility model, and is not intended to limit the utility model, and any modification, equivalent replacement and improvement made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A micro six-axis force sensor for a humanoid robot, characterized by, The elastic body (2) is in the shape of a whole disc, and the upper cover plate (1) and the lower cover plate (3) are arranged at the upper and lower ends of the elastic body (2); The elastic body (2) comprises an elastic body hub, a stress platform and four strain beams, the cross section of the strain beam is rectangular, the stress platform is hollow and arranged at the center of the elastic body hub, the four strain beams are arranged between the stress platform and the elastic body hub, and one end of the strain beam is connected to the elastic body hub and the other end is connected to the stress platform; the cable outlet (21) is arranged on the elastic body hub; the four strain beams are pasted with multiple strain gauges to form six Wheatstone bridges for measuring the forces and torques in the six directions of Fx, Fy, Fz, Tx, Ty and Tz.

2. The micro six-axis force sensor for humanoid robots according to claim 1, wherein, The upper end surface of the stress platform is 1.7mm higher than the upper end surface of the elastic body hub, and the lower end surface of the stress platform is 1.2mm lower than the lower end surface of the elastic body hub.

3. The micro six-axis force sensor for humanoid robots according to claim 1 or 2, characterized in that, The thickness of the micro six-dimensional force sensor is 9.2mm, and the diameter is 45mm.

4. The micro six-axis force sensor for humanoid robots according to claim 1, wherein, A total of 28 strain gauges are pasted on the four strain beams, respectively on the four surfaces of the four strain beams.

5. The micro six-axis force sensor for humanoid robots according to claim 4, wherein, The 28 strain gauges are R1-R28, wherein R1-R4 form a full bridge to measure Tx, R5-R8 form a full bridge to measure Ty, R9-R12 form a full bridge to measure Tz, R13-R16 form a full bridge to measure Fx, R17-R20 form a full bridge to measure Fy, and R21-R28 form a full bridge to measure Fz.

6. The micro six-axis force sensor for humanoid robots according to claim 1, wherein, The material of the elastic body (2) is stainless steel.

7. The micro six-axis force sensor for humanoid robots according to claim 1, wherein, The upper cover plate (1) and the lower cover plate (3) are respectively embedded in the grooves on the upper and lower end surfaces of the elastic body (2) and fixed, and the periphery is coated with sealant.

8. The micro six-axis force sensor for humanoid robots according to claim 1, wherein, The inner wall of the elastic body hub is provided with a wire pressing block (22) at the cable outlet (21), and the wire pressing block (22) is provided with a cable groove in communication with the cable outlet (21).

9. The micro six-axis force sensor for humanoid robots according to claim 8, wherein, The cable is led out of the cable outlet (21), and the cable outlet (21) is coated with sealant.

10. The micro six-axis force sensor for humanoid robots according to claim 1, wherein, The micro six-dimensional force sensor is an analog output.

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