Six-dimensional force sensor, torque force sensor and preparation method thereof

Abstract

The invention relates to the technical field of sensors, and provides a six-dimensional force and torque force sensor and a preparation method thereof.The six-dimensional force sensor is of a disc-shaped structure and comprises an outer supporting ring, an inner mass block and eight elastic beams connected between the outer supporting ring and the inner mass block; wherein the eight elastic beams comprise a first elastic beam and a second elastic beam which are alternately arranged around the inner mass block, the first elastic beam is a straight beam, the second elastic beam is a special-shaped beam, and a strain gauge preset on the main surface of each elastic beam responds to the strain of the elastic beam to generate a measurement signal; and the force and / or the torque applied to the inner mass block or the outer support ring can be determined according to the measurement signal. Due to the fact that the different elastic beams are different in shape and structure, the strain gauges are preset on the elastic beams of different types and positions, and the bridging mode is set, the output of each Wheatstone bridge is only sensitive to the force or the moment of force in the changed direction and is not sensitive to the force or the moment of force applied in other directions, and the decoupling capacity of the sensor structure is improved to the maximum degree.

Description

Technical Field

[0001] This application relates to the field of sensor technology, specifically to a six-dimensional force sensor, a torque force sensor, and a method for their fabrication. Background Technology

[0002] Existing six-dimensional force sensors are based on physical deformation and electrical signal conversion, and can simultaneously measure all forces and torques acting on an object in three-dimensional space, i.e., forces in three directions (F). x F y F z ) and torque in three directions (M) x M y M z Physical deformation can refer to the deformation that occurs when an elastic material is subjected to external force. This deformation causes a change in the resistance value of a strain gauge attached to the elastic material. By measuring the change in resistance value, the total force and torque of the applied external force can be calculated.

[0003] Existing technical solutions propose various different calculation methods, attempting to decouple the value of each measurement dimension from multiple sets of measurement signals, thereby estimating all forces and torques, but it is difficult to prove the accuracy of the calculation results. Summary of the Invention

[0004] This application proposes a six-dimensional force sensor, a torque force sensor, and methods for preparing the two sensors. The aim is to make each measurement signal reflect a single measurement dimension as much as possible, thereby reducing the difficulty of decoupling the measurement dimensions of the six-dimensional force from the measurement signals. This simplifies the complexity of the decoupling algorithm and calibration process, and improves the accuracy of the measurement results.

[0005] In a first aspect, embodiments of this application provide a six-dimensional force sensor, which has a disk-shaped structure and includes an outer support ring, an inner mass block, and eight elastic beams connecting the outer support ring and the inner mass block. The eight elastic beams include first and second elastic beams alternately arranged around the inner mass block. The first elastic beam is a straight beam; the second elastic beam is an irregularly shaped beam. Two straight beams are arranged along the X-axis direction of the sensor coordinate system, and the other two straight beams are arranged along the Y-axis direction of the sensor coordinate system. Each irregularly shaped beam includes a horizontal arm along the X-axis direction of the sensor coordinate system and a vertical arm connected to the horizontal arm along the Y-axis direction of the sensor coordinate system. Strain gauges pre-set on the main surface of each elastic beam generate measurement signals in response to the strain of the elastic beam, and the force and / or torque acting on the inner mass block or the outer support ring can be determined based on the measurement signals.

[0006] In this embodiment, since different elastic beams have different shapes and structures, the measurement signals of strain gauges pre-placed on elastic beams of different types and in different positions are sensitive to different forces / torques. Therefore, different combinations of multiple strain gauges can measure different forces / torques respectively, thereby accurately estimating each force and torque on the inner mass block or the outer support ring.

[0007] This application provides different ways of setting strain gauges on a straight beam (including the direction of adhesion of strain gauges, the position of adhesion, and the method of bridging), so that different Wheatstone bridges for measuring axial force, lateral force, and vertical force can respectively reflect the axial force, lateral force, and vertical force that the sensor needs to sense.

[0008] This application also provides different ways of setting strain gauges on irregularly shaped beams (including the bonding direction, bonding position, and bridge assembly method of the strain gauges), so that different Wheatstone bridges can respectively reflect the torque to be sensed by the sensor, wherein M x M y M z These represent the torques around the X, Y, and Z axes of the measurement sensor coordinate system, respectively.

[0009] The six-dimensional force sensor of this application can have strain gauges attached to two main surfaces of a disk-shaped structure, or only to one of the main surfaces, which reduces the difficulty of the attachment operation. In particular, it helps to improve the efficiency and accuracy of the attachment, especially in cases where it is difficult to attach strain gauges to the side in existing solutions.

[0010] Secondly, embodiments of this application provide a torque force sensor, which has a disk-shaped structure and includes an outer support ring, an inner mass block, and four elastic beams connected between the outer support ring and the inner mass block. Each elastic beam includes a horizontal arm along the X-axis direction in the sensor coordinate system and a vertical arm connected to the horizontal arm along the Y-axis direction in the sensor coordinate system. Strain gauges preset on the main surface of each elastic beam generate measurement signals in response to the strain of the elastic beam, and the torque and / or torque force on the inner mass block or the outer support ring can be determined based on the measurement signals.

[0011] Since the six-dimensional force sensor of this application can sense a single dimension of the six-dimensional force / torque through different Wheatstone bridges, the torque force sensor proposed in this application separates the Wheatstone bridge used to sense the torque of the rotating shaft in the six-dimensional force sensor, as well as the sensor structure on which the Wheatstone bridge depends, as a separate sensor for sensing torque M. z And / or a torque force sensor.

[0012] The strain gauges of this Wheatstone bridge can be attached to only one main surface of the disk-shaped structure, reducing the difficulty of traditional side-mounting strain gauge operations and improving the efficiency and accuracy of the attachment. Furthermore, the specific bridging method of the strain gauges ensures that the measurement signal of the Wheatstone bridge is only relevant to M.z The sensor is sensitive to changes in force, thereby improving its measurement accuracy and minimizing the complexity of signal decoupling calculations. Thirdly, this application provides a method for fabricating a six-dimensional force sensor, used to prepare the six-dimensional force sensor of this application embodiment.

[0013] Fourthly, this application provides a method for preparing a torque force sensor, which is used to prepare the torque force sensor of this application embodiment. Attached Figure Description

[0014] To more clearly illustrate this embodiment or existing technical solution, the drawings used in the description of the embodiment or existing technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A schematic diagram of a six-dimensional force sensor provided in an embodiment of this application;

[0016] Figure 2 for Figure 1 A schematic diagram of the arrangement scheme of each strain gauge on different elastic beams in the embodiment;

[0017] Figure 3 for Figure 2 A schematic diagram of the strain gauge resistance connection of a Wheatstone bridge for measuring six-dimensional forces.

[0018] Figure 4 for Figure 1 A schematic diagram of another arrangement scheme of strain gauges on different elastic beams in the embodiment;

[0019] Figure 5 for Figure 1 A schematic diagram of the force deformation of the six-dimensional force sensor in the embodiment;

[0020] Figure 6 A schematic diagram of a torque force sensor provided in an embodiment of this application;

[0021] Figures 7 to 9 for Figure 6 Schematic diagrams of different strain gauge configurations for the Wheatstone bridge in the torque force sensor of the embodiment;

[0022] Figure 10 for Figures 7 to 9 A schematic diagram of the strain gauge resistor connections for each Wheatstone bridge. Detailed Implementation

[0023] The term "and / or" used in this article describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. The symbol " / " in this article indicates that the related objects are in an "or" relationship; for example, A / B means A or B.

[0024] The terms "first" and "second," etc., used in the specification and claims herein are used to distinguish different objects, not to describe a specific order of objects. For example, "first procedure" and "second procedure," etc., are used to distinguish different procedures, not to describe a specific order of procedures.

[0025] To facilitate understanding of the solutions in the embodiments of this application, the technical terms involved in this document will be explained first.

[0026] A six-dimensional force sensor measures a complete load applied to it, which consists of a force vector and a torque vector. Each vector is further decomposed along three coordinate axes (X, Y, Z). Therefore, the output of a six-dimensional force sensor is six components F. x F y F z M x M y M z A set of.

[0027] F x Axial force refers to the force acting along the X-axis direction calibrated by the sensor.

[0028] F y Lateral force refers to the force acting along the Y-axis direction calibrated by the sensor.

[0029] F z Vertical force refers to the force acting along the Z-axis direction calibrated by the sensor. In many installation scenarios, the Z-axis is parallel to the direction of gravity, hence it is often called "vertical force".

[0030] M x The torque generated by rotation around the X-axis is similar to the torque generated by an airplane rolling or the inward / outward flicking of the wrist.

[0031] M y This refers to the torque generated by rotation around the Y-axis, similar to the torque generated by the pitching or nodding motion of an aircraft.

[0032] M z This refers to the torque generated by rotation around the Z-axis. It's similar to the torque generated by the yaw or pitching motion of an aircraft.

[0033] It is important to note that the definitions of the above terms all rely on the coordinate system defined by the six-dimensional force sensor itself. The user manual for a six-dimensional force sensor will clearly state its coordinate origin and the directions of the X, Y, and Z axes (usually indicated by arrows or colors, e.g., red for X, green for Y, and blue for Z). When using a six-dimensional force sensor, or when mentioning the force F measured by the six-dimensional force sensor... x F y F z M x M y M z When calculating the numerical values, it must be clear that the values ​​are based on the coordinate system defined by the six-dimensional force sensor itself.

[0034] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0035] This application provides a six-dimensional force sensor, which has a disk-shaped structure. Figure 1 The diagram shows a front view of the disk-shaped structure. The six-dimensional force sensor includes an outer support ring 1, an inner mass block 2, and eight elastic beams connecting the outer support ring 1 and the inner mass block 2. The eight elastic beams include four straight beams and four L-shaped beams alternately arranged around the inner mass block 2. Multiple sets of strain gauges (not shown) are pre-installed on the main surface of each elastic beam. Each set of strain gauges is used to measure one dimension of the six-dimensional force. Each strain gauge generates a measurement signal in response to the strain at its location on the elastic beam, and the force and / or torque values ​​for each measurement dimension are determined based on the measurement signals from each set of strain gauges.

[0036] To decouple the measurement signals of each set of strain gauges as much as possible, the position of each set of strain gauges on each elastic beam is determined so that the measurement signal is sensitive to the stress / torque in the measured dimension, but insensitive to the stress / torque in each other measurement dimension. Thus, the measurement signal of each measurement dimension in the six-dimensional force is obtained through the corresponding set of strain gauges.

[0037] In this embodiment, the measurement signal for each measurement dimension of the six-dimensional force is obtained through a Wheatstone bridge composed of a corresponding set of strain gauges. That is, six sets of strain gauges are pre-set on eight elastic beams, each set forming a Wheatstone bridge. The detection value of this Wheatstone bridge is used to estimate F. x F y F z M x M y M z The value of one of the measurement dimensions.

[0038] When measuring force using this six-dimensional force sensor, the external load (i.e., including F) is... x F y Fz M x M y M z The combined force and torque act on the force-receiving end of the six-dimensional force sensor, namely the internal mass block 2; the external load is transmitted to the core component of the sensor, namely the elastic body structure in this embodiment; the elastic body structure can decouple the complex external load as much as possible into multiple simple, measurable local strains; the strain gauges set on the elastic body structure convert the local strains into measurable electrical signals; the electrical signals are processed by analog-to-digital conversion, amplification, conditioning, filtering and other processes and then sent to the microprocessor (not shown) for calculation and output.

[0039] The difference between this embodiment and the prior art lies in the fact that the prior art requires complex mathematical decoupling of the electrical signal after analog-to-digital conversion, amplification, conditioning, and filtering before outputting the results for each measurement dimension. Specifically, the original digital voltage readings of each bridge channel read by the microprocessor are a mixture of the combined effects of all six-dimensional loads. This mixture needs matrix operations to decouple and obtain the force / torque values ​​for each independent dimension. This matrix operation essentially uses mathematical methods to solve inversely, precisely separating the force / torque values ​​for each independent dimension from the mixed original signal, thereby compensating for crosstalk that cannot be completely eliminated physically. In this embodiment, however, the original digital voltage readings of each bridge channel are themselves approximately decoupled, corresponding to F... x F y F z M x M y M z This reduces the complexity of decoupling algorithms and calibration by introducing one measurement dimension, thereby improving the accuracy of measurement results.

[0040] Specifically, this embodiment employs the following... Figure 1 The elastic body structure consisting of 8 elastic beams and the 6 Wheatstone bridges consisting of 6 sets of strain gauges on the elastic body structure obtained the values ​​corresponding to each measurement dimension.

[0041] like Figure 1 As shown, the eight elastic beams of this elastomeric structure are, in sequence, a first straight beam 10, a first L-shaped beam, a second straight beam 30, a second L-shaped beam, a third straight beam 50, a third L-shaped beam, a fourth straight beam 70, and a fourth L-shaped beam. Each L-shaped beam includes a horizontal arm and a vertical arm. Specifically, the first L-shaped beam includes a horizontal arm 21 and a vertical arm 22, the second L-shaped beam includes a horizontal arm 41 and a vertical arm 42, the third L-shaped beam includes a horizontal arm 61 and a vertical arm 62, and the fourth L-shaped beam includes a horizontal arm 81 and a vertical arm 82.

[0042] For example, such as Figure 2 As shown, the direction of the first straight beam 10 from the inner mass block 2 to the outer support ring 1 is the positive X-axis direction calibrated by the sensor, and the direction of the second straight beam 30 from the inner mass block 2 to the outer support ring 1 is the positive Y-axis direction calibrated by the sensor.

[0043] The measurement signals for axial force, lateral force, and vertical force are obtained by using different Wheatstone bridges set on the straight beam. Each Wheatstone bridge includes four strain gauges. Each strain gauge measures the radial deformation of the straight beam it is on, and each strain gauge is set along the centerline of the surface of the straight beam it is on.

[0044] Different measurement signals of torque around the X-axis, Y-axis, and Z-axis in the sensor coordinate system are measured by different Wheatstone bridges set on the L-shaped beam. Different strain gauges of the same Wheatstone bridge are on the same main surface. Each Wheatstone bridge includes four strain gauges. Each strain gauge is set along the centerline of the surface of the transverse / longitudinal arm and measures the deformation in the extension direction of the transverse / longitudinal arm.

[0045] Therefore, different forces / torques can be detected using six specific Wheatstone bridges. The position, orientation, and bridging method of the strain gauges in each specific Wheatstone bridge will have different effects on the detection results.

[0046] The following combination Figures 1-2 Explain how strain gauges are specifically arranged on the eight elastic beams of the above-mentioned elastic structure so that each group of strain gauges forms a different Wheatstone bridge.

[0047] Used to detect F x F y F z The Wheatstone bridge is mounted on a straight beam, as described below. x F y F z How should the strain gauges be set in the detection bridge?

[0048] Detecting axial force F x The Wheatstone bridge includes four strain gauges, two of which, R01 and R02, are located at the midpoint of the centerlines of the two surfaces of the first straight beam 10, and R03 and R04 are located at the midpoint of the centerlines of the two surfaces of the third straight beam 50, respectively. Furthermore, R01 and R03... Figure 2 On the main surface visible in the front view, R02 and R04 are on another main surface that is opposite to the aforementioned main surface.

[0049] Detecting lateral force F y The Wheatstone bridge includes four strain gauges, two of which, R05 and R06, are located at the midpoints of the centerlines of the two surfaces of the second straight beam 30, respectively. R07 and R08 are located at the midpoints of the centerlines of the two surfaces of the fourth straight beam 70, respectively. Furthermore, R05 and R07 are located at... Figure 2On the main surface visible in the front view, R06 and R08 are on another main surface that is opposite to the aforementioned main surface.

[0050] It should be noted that the lateral force F is detected. y Wheatstone bridge and detection of axial force F x The bridge configuration is similar to that of the Wheatstone bridge, the difference being that they are set on different straight beams along the Y-axis / X-axis directions in the sensor coordinate system.

[0051] Detecting vertical force F z The Wheatstone bridge includes four strain gauges, two of which, R09 and R10, are located at the midpoint of the centerlines of the two surfaces of the first straight beam 10, and R11 and R12 are located at the midpoint of the centerlines of the two surfaces of the third straight beam 50, respectively. Furthermore, R09 and R11... Figure 2 On the main surface visible in the front view, R10 and R12 are on another main surface that is opposite to the aforementioned main surface.

[0052] It should be noted that the vertical force F is being detected. z The Wheatstone electric bridge can also be positioned at the midpoint between the second straight beam 30 and the fourth straight beam 70, and refer to... Figure 2 The four strain gauges R09-R12 can be rotated 90 degrees counterclockwise. The measurement principle can be found in the above description. Figure 2 The descriptions of the medium strain gauges R09-R12 will not be repeated here.

[0053] It should also be noted that, Figure 2 R01 and R03 are both located on the inner part of the mass block 2 in the middle of the first straight beam 10 and the third straight beam 50, while R09 and R11 are both located on the outer part of the support ring 1 in the middle of the first straight beam 10 and the third straight beam 50. This is because adjacent R09 and R01, and adjacent R03 and R11 cannot simultaneously occupy the exact center of their respective straight beams. If the vertical force F is measured... z If the Wheatstone bridge is set on the second straight beam 30 and the fourth straight beam 70, then R01 and R03 can be set in a more central position on the straight beam, while R09 and R11 will cause R05 and R07 to be off-center.

[0054] It should be noted that for the Wheatstone bridge used to measure axial and lateral forces, each pair of arms is mounted on the same straight beam, while for the Wheatstone bridge used to measure vertical forces, each pair of adjacent arms is mounted on the same straight beam.

[0055] The above explanation Figure 2 The specific arrangement of strain gauges R01-R12 is shown, but this application is not limited thereto. Detection of axial force F xThe Wheatstone bridge includes four strain gauges that can also be positioned at other locations along the centerline of the straight beam surface, with R01 and R03, R02 and R04 being symmetrical about the YOZ plane in pairs; to detect the lateral force F. y The Wheatstone bridge includes four strain gauges that can also be positioned at other locations along the centerline of the straight beam surface, with R05 and R07, R06 and R08 each symmetrical about the XOZ plane; to detect the vertical force F. z The Wheatstone bridge can be used as a reference for testing F. x or F y The Wheatstone bridge is configured accordingly. These methods can largely eliminate interference from other measurement dimensions.

[0056] Used to detect M x M y M z The Wheatstone bridge is installed on an L-shaped beam. The following describes M. x M y M z How should the strain gauges be set in the detection bridge?

[0057] Detecting the torque M around the X-axis in the sensor coordinate system x The Wheatstone bridge includes four strain gauges R13-R16, which are sequentially positioned on the outermost support ring 1 at the middle of the horizontal arm 21 of the first L-shaped beam, the horizontal arm 41 of the second L-shaped beam, the horizontal arm 61 of the third L-shaped beam, and the horizontal arm 81 of the fourth L-shaped beam. Figure 2 The main surface visible in the front view.

[0058] Detecting the torque M along the Y-axis in the sensor coordinate system y The Wheatstone bridge includes four strain gauges R17-R20, which are respectively positioned at the intersection of the horizontal and vertical arms of the four L-shaped beams, and are all located at... Figure 2 The main surface visible in the front view.

[0059] Detecting the torque M around the Z-axis in the sensor coordinate system z The Wheatstone bridge includes four strain gauges R21-R24, which are positioned on the vertical arms of the four L-shaped beams adjacent to the inner mass block 3, and are all located at... Figure 2 The main surface visible in the front view is the opposite of the main surface.

[0060] The above explanation Figure 2 The specific arrangement of strain gauges R13-R24 is shown, but this application is not limited thereto. The torque M is measured. x Wheatstone bridge, torque detection M y Wheatstone bridge, torque detection M zThe strain gauges of the Wheatstone bridge can be located at any other effective position on the surface centerline of the four L-shaped beams, as long as the four strain gauges constituting the same Wheatstone bridge are symmetrical about the XOZ and YOZ planes in pairs. Figure 3 The bridge configuration shown can achieve decoupling of the torque measurement dimension, reducing the need for signal decoupling calculations. At the same time, it allows the four strain gauges of each Wheatstone bridge to be set only on the main surface, reducing the difficulty of the pasting operation and helping to improve the efficiency and accuracy of pasting.

[0061] The following combination Figure 2 and Figure 3 Note that the output of each Wheatstone bridge in this application is only sensitive to force or torque in one direction, and is not sensitive to force or torque in other directions.

[0062] Figure 3 The arrows marked on the strain gauge indicate the direction of resistance change; an upward arrow indicates increasing resistance, and a downward arrow indicates decreasing resistance. Among these, "F" indicates... x The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauges R01-R04 in response to stress deformation in the positive X-axis direction; "F" y The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauges R05-R08 in response to stress deformation in the positive Y-axis direction; "F" z The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauges R09-R12 in response to stress deformation in the negative Z-axis direction; "M" x The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauges R13-R16 in response to torque stress deformation in the negative X-axis direction; "M" x The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauges R01-R04 in response to torque stress deformation in the negative Y-axis direction; "M" z The "Wheatstone bridge" shows the increase / decrease in resistance of strain gauges R01-R04 in response to torque stress deformation in the negative Z-axis direction.

[0063] F x F y F z M x M y M z The working process of each corresponding Wheatstone bridge is as follows: in each pair of adjacent arms of the four strain gauges, one strain gauge is subjected to tension and the other to compression. The resistance of the strain gauges in the two pairs of arms changes simultaneously, and the changes in the adjacent arms are opposite, which together generate a large output signal. And through simulation verification, the position of the strain gauges and the specific bridge arrangement proposed in the above description can be sensitive only to the force or torque of the measured dimension, and not sensitive to other measurement dimensions.

[0064] It should be noted that this application does not limit the strain gauges in the six Wheatstone bridges to be configured as described in the above embodiments. Figure 2 The main surface visible in the front view, or Figure 2 The main surface visible in the front view is opposite to the main surface, and it is not limited to following the main surface. Figure 3 The resistor arrangement shown can be such that the upper left arm and the lower right arm are subjected to tension and compression respectively, while the upper right arm and the lower left arm are subjected to compression and tension respectively, with the resistance of the two opposing arms changing simultaneously and the adjacent arms changing in opposite directions.

[0065] It should also be noted that the references in this application apply only to F. x F y F z M x M y M z Sensitivity in one dimension does not mean that the amplitude of the measurement signal in other measurement dimensions is 0. Rather, it means that the amplitude of the measurement signal in other measurement dimensions is negligible compared to the amplitude in the corresponding measurement dimension. This is equivalent to or close to achieving decoupling of measurement signals in different measurement dimensions of six-dimensional force, thereby simplifying the decoupling algorithm and calibration complexity and improving the accuracy of measurement results.

[0066] Figure 4 This illustrates another arrangement of the strain gauges in the six Wheatstone bridges, compared to... Figure 2 Similar to the previous embodiment, each Wheatstone bridge meets the following requirements: in one pair of arms (upper left arm and lower right arm), one strain gauge is under tension and the other is under compression; in another pair of arms (upper right arm and lower left arm), one strain gauge is under compression and the other is under tension; the resistance of the strain gauges in both pairs of arms changes simultaneously, and the changes in adjacent arms are opposite. However, unlike the previous embodiment, in this example, strain gauges R01-R24 are all arranged on one main surface of the six-dimensional force sensor of the disk-shaped structure. It is not necessary to attach strain gauges to preset positions on the two main surfaces of the disk-shaped structure, thereby reducing the implementation steps and complexity of attaching strain gauges.

[0067] Specifically, Figure 4 and Figure 2 The difference in the arrangement of the strain gauges lies in the placement of strain gauges R01-R12. Specifically, R01-R04 are used to detect the axial force F. x The four strain gauges are still attached to the middle of straight beams 10 and 50, but no longer as... Figure 2 Instead of setting R01-R04 on different main surfaces of straight beam 10 and straight beam 50 respectively, the example is changed to the same main surface; R05-R08 are used to detect lateral force F. yThe four strain gauges are still attached to the middle positions of straight beams 30 and 70, and are also changed to be on the same main surface; R09-R12 are used to detect the vertical force F. z The four strain gauges were moved from L-shaped beams 20 and 80 to the two ends of straight beams 10 and 50, and were also moved to the same main surface.

[0068] For measuring vertical force F z The strain gauges R09-R12, due to Figure 2 In the example, the strain gauges to be installed on L-shaped beams 20 and 80 already occupy a significant amount of space, thus lacking the space to unfold R09-R12 onto the same main surface of L-shaped beams 20 and 80. Therefore, this application proposes as follows: Figure 4 As shown, strain gauges R09-R12 are positioned at both ends of the same main surface on straight beams 10 and 50. Figure 4 The working process of the Wheatstone bridge composed of medium strain gauges R09-R12 and Figure 2 The basic structure is the same as in the previous section, and simulations have verified that this position only applies to vertical force F. z Sensitive, therefore, Figure 4 The R09-R12 positions shown are also for detecting the vertical force F. z The preferred positions of a set of strain gauges in a Wheatstone bridge. For example, R10 and R12 are both located on the straight beam, between the inner mass block 2 and the outer support ring 1, and slightly off the position of the outer support ring 1; R09 and R11 are both located on the straight beam, between the inner mass block 2 and the outer support ring 1, and slightly off the position of the inner mass block 2.

[0069] Measurement M z The preferred position is the vertical beam near the mass block.

[0070] Combination Figure 2 and Figure 4 As the example shows, it is used to measure torque M x M y M z The Wheatstone bridge is mounted on four L-shaped beams. Each L-shape has a transverse arm along the X-axis and a longitudinal arm along the Y-axis. Each of the four transverse / longitudinal arms is equipped with a strain gauge, and the four strain gauges together form a structure for measuring the torque M. x M y M z A Wheatstone bridge.

[0071] Measuring torque M x M y M z Each Wheatstone bridge can use strain gauges. Figure 2 / Figure 4The various locations shown can be connected in a manner that... Figure 3 M shown x / M y / M z Wheatstone bridge, so that it is respectively for torque M x M y M z It is sensitive to one of the measurement dimensions, but insensitive to the other measurement dimensions.

[0072] It should also be noted that, to decouple the output signal of the Wheatstone bridge corresponding to each measurement dimension from other measurement dimensions as much as possible, the adjacent arm resistors (strain gauges) constituting the same Wheatstone bridge should be pairwise symmetrical about the YOZ plane in the sensor coordinate system, or pairwise symmetrical about the origin of the sensor coordinate system. Similarly, the opposite arm resistors (strain gauges) constituting the same Wheatstone bridge should be pairwise symmetrical about the YOZ plane in the sensor coordinate system, or pairwise symmetrical about the origin of the sensor coordinate system. That is, as... Figure 3 As shown, each Wheatstone bridge outputs a differential voltage at its two output terminals ("+" and "-" terminals), and each output terminal is connected to ground via a strain gauge. The two strain gauges connected to ground for different Wheatstone bridges are positioned either on the two horizontal / vertical arms within the positive X half-space, or on the two horizontal / vertical arms within the negative X half-space, or on the two horizontal / vertical arms within the XY half-spaces of the same sign, or on the two horizontal / vertical arms within the XY half-spaces of opposite signs. The XY half-spaces of the same sign refer to the space of the first, third, fifth, and seventh octaves of the sensor coordinate system, while the XY half-spaces of opposite signs refer to the space of the second, fourth, sixth, and eighth octaves of the sensor coordinate system.

[0073] In some examples, the strain gauges mounted on the elastic beam are either resistance strain gauges or charge strain gauges. In this example, due to the strain of the elastic beam, the resistance / charge of the strain gauge changes, which in turn changes the measurement signal. Since the strain gauge's measurement signal has different sensitivities to different forces / torques, it is possible to estimate the values ​​of each measurement dimension based on changes in resistance / charge.

[0074] In some examples, strain gauges are positioned on the elastic beam at predetermined locations using a glass micro-fusion process or a patch process. In this example, the strain gauges are securely mounted on the elastic beam, minimizing the possibility of measurement deviations caused by minute displacements between the strain gauges and the elastic beam.

[0075] In some examples, the L-shaped beams among the eight elastic beams of the six-dimensional force sensor are arranged symmetrically at the center. Based on the requirement of decoupling the measurement dimensions of each group of strain gauges as much as possible, and with the principle that each group of strain gauges corresponds to a single direction of force or torque sensitivity, the positions of various strain gauges are set to improve the accuracy of the measurement results.

[0076] This application provides a method for fabricating a six-dimensional force sensor, which includes the following steps:

[0077] Fabricate and connect the components of a six-dimensional force sensor;

[0078] Multiple strain gauges are installed at preset positions on the main surface of each elastic beam;

[0079] By connecting each strain gauge to the calculation circuit, a six-dimensional force sensor is obtained.

[0080] In some examples, the fabrication method of this six-dimensional force sensor also includes the following steps:

[0081] The six-dimensional force sensor was sealed and inspected as a finished product.

[0082] Performance testing of the finished product of the six-dimensional force sensor;

[0083] After the finished product passes the performance test, the six-dimensional force sensor is packaged.

[0084] It should be noted that this application does not limit the irregular beam to the L-shaped beam shown in the attached drawings, but only requires that the irregular beam include the L-shaped structure of the embodiment of this application, and that strain gauges be attached to the straight beam and the L-shaped structure to reduce interference between measurement signals in various measurement dimensions and effectively reduce F x F y F z M x M y M z The measured values ​​should be decoupled from the actual measured signals as much as possible.

[0085] This application provides a torque force sensor, such as... Figure 6 The structure is disc-shaped, comprising an outer support ring 1, an inner mass block 2, four L-shaped elastic beams connecting the outer support ring 1 and the inner mass block 2, and strain gauges positioned at predetermined locations on the main surface of the disc-shaped structure along the four L-shaped elastic beams. Each L-shaped elastic beam includes a horizontal arm along the X-axis of the sensor coordinate system and a vertical arm connected to the horizontal arm along the Y-axis of the sensor coordinate system. The measurement signal generated by the strain gauge in response to the deformation of the elastic beam is the measurement signal of a torque force sensor.

[0086] Figure 6One arrangement of the longitudinal arms 01-04 and the transverse arms 01'-04' is shown, but this application is not limited thereto. The longitudinal arms 01, 02, 03, and 04 can each be rotated 90° to become transverse arms extending from the inner mass block 2, thereby converting the transverse arms 01'-04', which are perpendicular to the longitudinal arms 01, 02, 03, and 04, into longitudinal arms connected to the outer support ring 1. Alternatively, an L-shaped beam can be constructed between the outer support ring 1 and the inner mass block 2, and the L-shaped transverse and longitudinal arms can be arranged along the X and Y axes of the sensor coordinate system, respectively.

[0087] Figures 7 to 9 The optional positions of strain gauges R1-R4 on the four L-shaped elastic beams are shown. Figure 10 It shows Figures 7-9 Each strain gauge R1-R4 in the circuit forms a Wheatstone bridge, with the power supply applied between VDD and GND, and the measurement signal is output through the + / - output terminals. Under the applied rotational torque M... z At this time, R1 and R2 form one pair of adjacent arms, and R3 and R4 form another pair of adjacent arms. In both pairs of adjacent arms, one strain gauge is subjected to compression and the other to tension, and the directions of change are opposite. This ensures that the output measurement signal is consistent with M. z It is sensitive to changes.

[0088] The working principle and technical effects of the Wheatstone bridge described above, as well as the orientation and specific location of the strain gauges, can be found in the above description. Figure 2 , Figure 4 In the embodiment, M is measured z The details of the Wheatstone bridge and the arrangement of strain gauges R21-R24 in constructing the Wheatstone bridge will not be elaborated upon in this application.

[0089] This application provides a method for fabricating a torque force sensor, which includes the following steps:

[0090] Fabricate and connect the various components of the torque force sensor;

[0091] Multiple strain gauges are installed at preset positions on the main surface of each elastic beam;

[0092] Connect each strain gauge to the calculation circuit to obtain the torque force sensor.

[0093] In some examples, the fabrication method of this torque force sensor further includes the following steps:

[0094] The torque force sensor is sealed and inspected as a finished product.

[0095] Perform finished product performance testing on the torque force sensor;

[0096] After the finished product passes the performance test, the torque force sensor is packaged.

[0097] It should be noted that this application does not limit the irregular beam to the L-shaped beam shown in the attached drawings, but only requires that the irregular beam include the L-shaped structure of the torque force sensor embodiment of this application, and that strain gauges be attached to the straight beam and the L-shaped structure to reduce interference between measurement signals in various measurement dimensions and effectively reduce the interference between the measurement signals in various measurement dimensions. z The measured values ​​should be decoupled from the actual measured signals as much as possible.

[0098] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A six-dimensional force sensor, which has a disk-shaped structure, characterized in that, include: Outer support ring; Internal mass block; Eight elastic beams are connected between the outer support ring and the inner mass block, and the eight elastic beams generate strain when the inner mass block is displaced relative to the outer support ring; as well as Multiple strain gauges are disposed at predetermined positions on the main surfaces of the eight elastic beams and are configured to generate measurement signals in response to the strain. The main surface is a surface that is parallel or substantially parallel to the disk surface of the disk-shaped structure. The eight elastic beams include four first elastic beams and four second elastic beams; the first elastic beams are straight beams; the second elastic beams are irregularly shaped beams; the first elastic beams and the second elastic beams are alternately arranged around the inner mass block; the two straight beams are arranged along the X-axis direction in the sensor coordinate system, and the other two straight beams are arranged along the Y-axis direction in the sensor coordinate system; each irregularly shaped beam includes a horizontal arm along the X-axis direction in the sensor coordinate system, and a vertical arm connected to the horizontal arm along the Y-axis direction in the sensor coordinate system.

2. The six-dimensional force sensor according to claim 1, characterized in that, The measurement signals for axial force, lateral force, and vertical force are obtained by using different Wheatstone bridges set on the straight beam. Each Wheatstone bridge includes four strain gauges. Each strain gauge measures the radial deformation of the straight beam it is on, and each strain gauge is set along the centerline of the surface of the straight beam it is on.

3. The six-dimensional force sensor according to claim 2, characterized in that, Two straight beams are set along the X-axis direction in the sensor coordinate system, and a first Wheatstone bridge is set to measure the axial force. A second Wheatstone bridge is set up to measure lateral force on two straight beams positioned along the Y-axis in the sensor coordinate system. as well as A third Wheatstone bridge is set up to measure vertical force using two straight beams positioned along the X-axis of the sensor coordinate system or two straight beams positioned along the Y-axis of the sensor coordinate system.

4. The six-dimensional force sensor according to claim 1, characterized in that, The four horizontal arms are symmetrical about the YOZ plane in the sensor coordinate system in pairs, and also symmetrical about the XOZ plane in the sensor coordinate system in pairs. The four longitudinal arms are symmetrical about the YOZ plane in the sensor coordinate system in pairs, and also symmetrical about the XOZ plane in the sensor coordinate system in pairs.

5. The six-dimensional force sensor according to any one of claims 1 to 4, characterized in that, Different measurement signals of torque around the X-axis, Y-axis, and Z-axis in the sensor coordinate system are obtained by measuring different Wheatstone bridges set on the irregular beam; different strain gauges of the same Wheatstone bridge are on the same main surface; Each Wheatstone bridge includes four strain gauges; each strain gauge is positioned along the centerline of the surface of the transverse / longitudinal arm and measures the deformation in the direction of extension of the transverse / longitudinal arm.

6. The six-dimensional force sensor according to claim 5, characterized in that, The four strain gauges of each Wheatstone bridge are positioned as follows: in the middle of each of the four horizontal arms, with the four horizontal arms connected to the connection points of the four vertical arms, or in the position of each of the four vertical arms close to the inner mass block.

7. The six-dimensional force sensor according to claim 5 or 6, characterized in that, The torque about the X-axis in the sensor coordinate system is measured by the fourth Wheatstone bridge; The two strain gauges of each pair of arms of the fourth Wheatstone bridge are symmetrical about the YOZ plane in the sensor coordinate system. The two strain gauges of each pair of adjacent arms of the fourth Wheatstone bridge are symmetrical about the origin of the sensor coordinate system; The fourth Wheatstone bridge outputs a differential voltage between its first and second terminals; The first strain gauge is connected between the first terminal and the ground terminal; the second strain gauge is connected between the second terminal and the ground terminal; the first strain gauge and the second strain gauge are disposed on two horizontal / vertical arms in the positive X half-space, or the first strain gauge and the second strain gauge are disposed on two horizontal / vertical arms in the negative X half-space.

8. The six-dimensional force sensor according to any one of claims 5 to 7, characterized in that, The torque about the Y-axis in the sensor coordinate system was measured using a fifth Wheatstone bridge; and The two strain gauges of each pair of adjacent arms of the fifth Wheatstone bridge are symmetrical about the YOZ plane in the sensor coordinate system. The two strain gauges of each pair of arms of the fifth Wheatstone bridge are symmetrical about the origin of the sensor coordinate system; The fifth Wheatstone bridge outputs a differential voltage between the third and fourth terminals; the third strain gauge is connected between the third terminal and the ground terminal; the third strain gauge and the fourth strain gauge are disposed on two horizontal / vertical arms in the XY half-space with the same sign, or the third strain gauge and the fourth strain gauge are disposed on two horizontal / vertical arms in the XY half-space with opposite signs.

9. The six-dimensional force sensor according to any one of claims 5 to 8, characterized in that, The torque about the Z-axis in the sensor coordinate system is measured by the sixth Wheatstone bridge; The two strain gauges of each pair of adjacent arms of the sixth Wheatstone bridge are symmetrical about the YOZ plane in the sensor coordinate system. The two strain gauges of each pair of arms of the sixth Wheatstone bridge are symmetrical about the origin of the sensor coordinate system; The sixth Wheatstone bridge outputs a differential voltage between its fifth and sixth terminals; The fifth strain gauge is connected between the fifth terminal and the ground terminal; the sixth strain gauge is connected between the sixth terminal and the ground terminal; the fifth strain gauge and the sixth strain gauge are disposed on two horizontal / vertical arms in the positive X half-space, or the fifth strain gauge and the sixth strain gauge are disposed on two horizontal / vertical arms in the negative X half-space.

10. The six-dimensional force sensor according to any one of claims 1 to 9, characterized in that, The plurality of strain gauges are resistive strain gauges or charge strain gauges.

11. The six-dimensional force sensor according to any one of claims 1 to 10, characterized in that, Each strain gauge is placed at a predetermined position on the elastic beam using a glass micro-melting process or a patching process.

12. A method for preparing a six-dimensional force sensor as described in any one of claims 1 to 11, characterized in that, Includes the following steps: Fabricate and connect the components of the six-dimensional force sensor; The plurality of strain gauges are set at predetermined positions on the main surface of each elastic beam; Connect each strain gauge to the calculation circuit to obtain the six-dimensional force sensor.

13. A torque force sensor, which has a disk-shaped structure, characterized in that, include: Outer support ring; Internal mass block; Four elastic beams are connected between the outer support ring and the inner mass block, and these four elastic beams generate strain when the inner mass block is displaced relative to the outer support ring; and A set of strain gauges are disposed at predetermined positions on the main surfaces of the four elastic beams and are configured to generate measurement signals in response to the strain. The main surface is a surface that is parallel or substantially parallel to the disk surface of the disk-shaped structure. Each elastic beam includes a horizontal arm along the X-axis in the sensor coordinate system and a vertical arm connected to the horizontal arm along the Y-axis in the sensor coordinate system.

14. The torque force sensor according to claim 13, characterized in that, The four horizontal arms are symmetrical about the YOZ plane in the sensor coordinate system in pairs, and also symmetrical about the XOZ plane in the sensor coordinate system in pairs. The four longitudinal arms are symmetrical about the YOZ plane in the sensor coordinate system in pairs, and also symmetrical about the XOZ plane in the sensor coordinate system in pairs.

15. The torque force sensor according to claim 13, characterized in that, The torque of the rotating shaft is measured by a Wheatstone bridge consisting of four strain gauges in the set of strain gauges; the four strain gauges are on the same main surface. Each of the four strain gauges is positioned along the centerline of the horizontal / vertical arm and measures the deformation in the direction of extension of the horizontal / vertical arm.

16. The torque force sensor according to any one of claims 13 to 15, characterized in that, The four strain gauges are positioned as follows: in the middle of each of the four horizontal arms, with each of the four horizontal arms connected to the connection point of the four vertical arms, or in a position close to the inner mass block of each of the four vertical arms.

17. The torque force sensor according to claim 16, characterized in that, The two strain gauges of each pair of adjacent arms of the Wheatstone bridge are symmetrical about the YOZ plane in the sensor coordinate system. The two strain gauges of each pair of arms of the Wheatstone bridge are symmetrical about the origin of the sensor coordinate system; The Wheatstone bridge outputs a differential voltage between the seventh and eighth terminals; the voltage at the seventh terminal is the voltage of the seventh strain gauge relative to the ground terminal; the voltage at the eighth terminal is the voltage of the eighth strain gauge relative to the ground terminal; the seventh and eighth strain gauges are disposed on two horizontal / vertical arms in the positive X half-space, or the seventh and eighth strain gauges are disposed on two horizontal / vertical arms in the negative X half-space.

18. The torque force sensor according to any one of claims 13 to 17, characterized in that, The plurality of strain gauges are resistive strain gauges or charge strain gauges.

19. The torque force sensor according to any one of claims 13 to 18, characterized in that, Each strain gauge is placed at a predetermined position on the elastic beam using a glass micro-melting process or a patching process.

20. A method for manufacturing a torque force sensor as described in any one of claims 13 to 19, characterized in that, Includes the following steps: Prepare and connect the components of the torque force sensor; The plurality of strain gauges are set at predetermined positions on the main surface of each elastic beam; Connect each strain gauge to the calculation circuit to obtain the torque force sensor.

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