Multi-dimensional force measuring device

Abstract

A multi-dimensional force measuring device provided by the present invention comprises a fixed part and a loading part which are coaxially arranged, and a composite beam structure between the fixed part and the loading part, the composite beam structure comprises a circumferential beam and a radial beam, the radial beam is vertically connected to the width center of the circumferential beam to form a core sensing unit, and the circumferential beam is provided with symmetrical first strain structures with specific directions. The device is used for high-sensitivity radial force measurement. The device also comprises a selectable support beam as an independent rigidity and measurement module, and the spatial decoupling of signals is realized by physically separating sensitive areas of different force components to the roots of the circumferential beam and the radial beam and the support beam. The problems that rigidity and sensitivity are difficult to consider and inter-dimension crosstalk is serious are solved, and the machining manufacturability and the dynamic performance are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a multidimensional force measurement device. Background Technology

[0002] Multidimensional force sensors are precision measuring devices capable of simultaneously detecting force / torque components in multiple directions, widely used in robotics, high-end equipment, aerospace, and other fields. As application scenarios place increasingly higher demands on sensor performance, sensor design faces a challenging balance between high load-bearing capacity, high stiffness, high sensitivity, and good isotropy. On one hand, increasing the load-bearing capacity and the structure's natural frequency requires increasing the stiffness of the elastic body, but this often leads to a decrease in sensitivity. On the other hand, obtaining high-sensitivity signals typically requires designing strain concentration structures on the elastic body, but this may weaken the overall stiffness and introduce complex interdimensional coupling, reducing measurement accuracy and decoupling performance. Furthermore, traditional elastic body structures are complex to manufacture, especially designs with complex three-dimensional hollows or irregular surfaces, requiring extremely high machining precision; even small machining errors can significantly affect the sensor's static and dynamic performance indicators. Therefore, a novel multidimensional force measurement device structure is urgently needed that can achieve high sensitivity and low interdimensional coupling while ensuring high stiffness and a large range, and possesses excellent manufacturability. Summary of the Invention

[0003] This invention provides a multi-dimensional force measurement device to solve technical problems such as the difficulty in balancing the stiffness and sensitivity of elastomer structures, severe signal crosstalk between measurement dimensions, and difficulty in ensuring processing accuracy.

[0004] The multidimensional force measuring device provided by the present invention includes a fixed part, a loading part, and a composite beam structure connected between the two coaxially arranged. The composite beam structure includes a beam body, which includes a circumferential beam arranged around the periphery and a radial beam arranged radially. One end of the radial beam is perpendicularly connected to the center position of the circumferential beam, and the other end is connected to the fixed part or the loading part. On the circumferential beam, corresponding to the connection position of each radial beam, at least one pair of first strain holes or first strain grooves penetrating along its height direction are provided.

[0005] The first strain hole is symmetrical about the centerline of the circumferential beam in the width direction and the central radial plane of the corresponding radial beam, and the major axis of the first strain hole is consistent with the length direction of the circumferential beam. The first strain groove is symmetrical about the centerline of the circumferential beam in the width direction and the central radial plane of the corresponding radial beam, and its extension direction is consistent with the length direction of the circumferential beam.

[0006] In an optional embodiment of the present invention, the beam body includes a support beam disposed between adjacent radial beams, one end of the support beam being connected to the fixing part and the other end being connected to the loading part; The support beam is provided with a second strain hole or a second strain groove extending through its height at one end where it is connected to the loading part. The second strain hole or the second strain groove is arranged symmetrically about the central radial plane of the support beam.

[0007] In an optional embodiment of the present invention, radial force measuring elements are provided on the two side planes corresponding to the first strain hole or the first strain groove, the radial force measuring elements are arranged along the width direction of the circumferential beam, and axial force measuring elements are provided on the surface of the support beam, the axial force measuring elements are arranged along the height direction of the support beam.

[0008] In an optional embodiment of the present invention, a bending moment measuring element is provided on the surface of the radial beam, the bending moment measuring element is arranged along the height direction of the radial beam, and a torque measuring element is provided on the two side planes corresponding to the second strain hole or the second strain groove, the torque measuring element is arranged along the width direction of the support beam.

[0009] In an optional embodiment of the present invention, the radial beam includes an I-beam segment disposed on one side close to or away from the circumferential beam and symmetrically disposed about the central radial plane and the central height plane of the radial beam. The I-beam segment includes an upper flange and a lower flange that are parallel to each other, and a web connecting the upper flange and the lower flange.

[0010] In an optional embodiment of the present invention, an axial force measuring element is provided on the side of the web of the I-beam segment, the axial force measuring element is at a 45° angle with the neutral axis of the I-beam segment, and a bending moment measuring element is provided on the upper surface of the upper flange and the lower surface of the lower flange of the I-beam segment, and is located at the center line position of the upper surface of the upper flange and the lower surface of the lower flange. Radial force measuring elements are provided on the two side planes corresponding to the first strain hole or the first strain groove, and the radial force measuring elements are arranged along the width direction of the circumferential beam.

[0011] In an optional embodiment of the present invention, at least one pair of third strain holes are provided on the radial beam, extending through its width direction, and the third strain holes are arranged symmetrically about the center height plane of the radial beam.

[0012] In an optional embodiment of the present invention, the radial beam is further provided with an axial force measuring element, which is arranged on both sides of the third strain hole along the height direction of the radial beam, and a bending moment measuring element, which is arranged on both sides of the third strain hole along the height direction of the radial beam. Radial force measuring elements are provided on the two side planes corresponding to the first strain hole or the first strain groove, and the radial force measuring elements are arranged along the width direction of the circumferential beam.

[0013] In an optional embodiment of the present invention, a fourth strain hole is provided on the radial beam, which extends through the beam along its height direction. The fourth strain hole is an elliptical hole, a waist-shaped hole, or a rectangular hole.

[0014] In an optional embodiment of the present invention, torque measuring elements are provided on the two side planes corresponding to the fourth strain hole, and the torque measuring elements are arranged along the width direction of the radial beam.

[0015] The beneficial effects of the present invention are as follows: The multi-dimensional force measuring device proposed in this invention forms a core sensing unit by vertically connecting a radial beam to the center of the width of a circumferential beam, and symmetrically opening a first strain hole / groove in a specific direction on the circumferential beam. It can be formed by simple processing from the upper and lower surfaces, which significantly reduces the difficulty and cost of high-precision processing. At the same time, the high-rigidity structure effectively improves the overall natural frequency of the sensor and ensures the measurement stability under dynamic load. By introducing a support beam that connects the fixed part and the loading part at both ends as an independent auxiliary stiffness and measurement module, and opening a second strain hole / groove at its end, the synergistic improvement of structural stiffness enhancement and local measurement sensitivity adjustment function is achieved, enabling the sensor to finely optimize measurement sensitivity while ensuring high stiffness and large range. By providing a variety of radial beam variant structures, including I-beam segments and third strain holes, and combining them with the corresponding strain measurement element layout strategy, a set of flexibly configurable elastomer design systems has been formed, which can select the optimal sensor configuration according to different needs and have a wide range of engineering adaptability. By arranging the sensitive elements separately in different beams or in different locations on the same beam, the six-dimensional force signal is decoupled at the physical structure level, which fundamentally reduces mechanical and electrical signal crosstalk between measurement channels and significantly improves the purity and overall accuracy of the original measurement signal. This invention systematically solves the multiple contradictions between stiffness, sensitivity, accuracy, manufacturability and dynamic performance in the design of multidimensional force sensors, and provides a complete solution that combines high performance, high reliability, excellent manufacturability and high configurability. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] In the attached diagram: Figure 1 This is a front view of a multi-dimensional force measuring device provided in an embodiment of the present invention; Figure 2 This is a front view of a multi-dimensional force measuring device provided in another embodiment of the present invention; Figure 3 This is a three-dimensional structural schematic diagram of a multi-dimensional force measuring device provided in one embodiment of the present invention; Figure 4 This is a three-dimensional structural schematic diagram of a multi-dimensional force measuring device provided in another embodiment of the present invention; Figure 5 This is a front view of a multidimensional force measuring device provided in another embodiment of the present invention.

[0018] The attached figures are labeled as follows: 100. Fixing part; 200. Loading part; 300. Circumferential beam; 400. Radial beam; 500. Support beam; 310, First strain gauge hole; 320, First strain groove; 410, I-beam segment; 420, Third strain gauge hole; 430, Fourth strain gauge hole; 510, Second strain gauge hole; 520, Second strain groove. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0022] Multidimensional force sensors are core components in modern precision measurement. Their elastic structure directly determines key indicators such as stiffness, sensitivity, decoupling performance, and dynamic response. Most existing multidimensional force sensors employ slender beams or complex hollow structures in pursuit of high sensitivity, resulting in limited stiffness and measurement range, poor dynamic performance, or increased cross-sectional dimensions to improve stiffness, leading to decreased sensitivity, bulky size, and difficulty in achieving effective signal decoupling within a compact space. Furthermore, traditional designs often have fixed structures for specific applications, lacking flexibility and adaptability.

[0023] Please see Figures 1 to 5 This invention proposes a multidimensional force measurement device, comprising a fixed part 100, a loading part 200, and a composite beam structure connected between them, all arranged coaxially. The composite beam structure includes a beam body and strain measuring elements disposed thereon. The beam body includes a circumferential beam 300 arranged around the beam and a radial beam 400 arranged radially. One end of the radial beam 400 is perpendicularly connected to the center of the circumferential beam 300, and the other end is connected to either the fixed part 100 or the loading part 200. At least one strain measuring element is provided on the circumferential beam 300 corresponding to the connection position of each radial beam 400. The first strain hole 310 or the first strain groove 320 extends along its height direction; wherein the first strain hole 310 is symmetrical about the center line of the circumferential beam 300 in the width direction and the central radial plane of the corresponding radial beam 400, and the long axis direction of the first strain hole 310 is consistent with the length direction of the circumferential beam 300, and the first strain groove 320 is symmetrical about the center line of the circumferential beam 300 in the width direction and the central radial plane of the corresponding radial beam 400, and its extension direction is consistent with the length direction of the circumferential beam 300.

[0024] Please see Figures 1 to 5, in the multi-dimensional force measurement device of the present invention, the first strain hole 310 or the first strain groove 320 is only a simple geometric feature that penetrates along the height direction, and only needs to be formed by drilling or milling from the upper and lower surfaces of the blank, without complex side processing or three-dimensional special-shaped contour processing, greatly reducing the dependence on precision machining and reducing the risk of structural asymmetry caused by cumulative errors in complex processes. Therefore, it can better ensure the dimensional consistency and machining accuracy in mass production, and guarantee the measurement accuracy and reliability of the sensor from the manufacturing source. The radial beam 400 is vertically connected to the center position of the width of the circumferential beam 300, forming a "dry" - shaped (with the vertical bar in the middle) core sensing unit with excellent mechanical symmetry. As a high - stiffness design itself, it avoids the defect that the floating beam design significantly reduces the overall natural frequency of the sensor. The core unit of the present invention has a higher local stiffness, thus effectively improving the overall natural frequency of the sensor, making it less likely to occur structural resonance when a large - mass load is introduced at the end, ensuring the measurement accuracy and stability under dynamic loads, and solving the contradiction that it is difficult to have both high sensitivity and excellent dynamic performance. At the same time, this core unit constitutes a basic sensing module, stably providing excellent radial force decoupling measurement ability, which is the starting point for sensor performance expansion and configuration. Through further optimization of the beam body, flexible configuration of the sensor can be achieved.

[0025] Please refer to Figures 1 to 5In an optional embodiment of the present invention, the fixing part 100 and the loading part 200 are coaxially arranged annular or disc-shaped structures. The fixing part 100 is used to install the entire measuring device onto an external base, and the loading part 200 is used to bear external multidimensional loads. The corresponding ends of the composite beam structure are connected to the fixing part 100 and the loading part 200, thereby forming a stable force transmission path. It is understood that in practical applications, the roles of the fixing part 100 and the loading part 200 can be interchanged according to installation requirements, that is, to realize two basic force transmission modes: "internal fixing-external loading" or "external fixing-internal loading", so that the device can flexibly adapt to different installation spaces and stress scenarios. The structural strength and connection rigidity of the fixing part 100 and the loading part 200 are specially designed to ensure that the external load can be transmitted to the core composite beam structure completely and with low loss, avoiding measurement errors caused by deformation of the installation interface. It should be noted that, in order to facilitate the analysis and measurement of forces or moments, a three-dimensional Cartesian coordinate system is established with the geometric center point of the structure as the origin. In this design, the axis perpendicular to the horizontal plane of the fixing part 100 is defined as the Z-axis, representing the direction of the axial force component Fz and the torque component Mz about the Z-axis. Within the horizontal plane of the fixing part 100, two mutually perpendicular axes are defined as the X-axis and Y-axis, representing the radial force components Fx and Fy, and the directions of the bending moment component Mx about the X-axis and the bending moment component My about the Y-axis. By concentrating the force or torque on the loading part 200, the stress response of each part of the subsequent elastic body can be ensured to have good predictability and symmetry, laying the foundation for accurate measurement and theoretical decoupling.

[0026] Please see Figures 1 to 5 In an optional embodiment of the present invention, one or more pairs of first strain holes 310 or first strain grooves 320 extending along the height direction are provided on the circumferential beam 300. Each pair of strain holes or strain grooves is strictly symmetrical about the centerline of the width direction of the circumferential beam 300. When a radial force is applied to the device, the force flow is transmitted to the circumferential beam 300 through the radial beam 400, causing the circumferential beam 300 to bend. Since the long axis or extension direction of the first strain hole 310 or first strain groove 320 is parallel to the bending neutral layer of the beam, significant bending stress concentration will occur in the areas on both sides due to the weakening of the cross-section, while the stress concentration effect at the end of the hole / groove is relatively weak. This design achieves high strain amplification while minimizing the weakening of the overall axial stiffness of the circumferential beam 300. This structure enables radial force measurement to have high sensitivity and high linearity. Due to its symmetry, it can achieve a nearly consistent mechanical response in the X and Y directions (radial). It can also largely offset the interference strain caused by loads in non-target directions, significantly improving the purity and decoupling performance of radial force measurement and laying the structural foundation for the isotropic performance of the sensor.

[0027] Please see Figures 1 to 2In an optional embodiment of the present invention, the beam body further includes a support beam 500, which is disposed between adjacent radial beams 400. One end of the support beam 500 is connected to the fixing part 100, and the other end is connected to the loading part 200. A second strain hole 510 or a second strain groove 520 is provided at the end of the support beam 500 connected to the loading part 200, which extends through the support beam 500 along its height direction. The second strain hole 510 or the second strain groove 520 are symmetrically arranged about the central radial plane of the support beam 500. In this embodiment, by introducing a support beam 500 as an auxiliary stiffness and measurement unit, its two ends are directly and rigidly connected between the fixed part 100 and the loading part 200, which can provide additional stiffness support, especially improving the overall structural stiffness and stability of the lifting device when subjected to large axial loads or overturning moments, thereby expanding the range of the sensor and increasing its natural frequency. Through the different settings of the structure and size of the support beam 500 and the radial beam 400, the measurement requirements of the range, sensitivity and dynamic performance of forces and moments in different directions can be better adapted. Moreover, as an auxiliary measurement component, some strain measurement elements can be arranged on the support beam 500, thereby avoiding positional interference and signal crosstalk with the strain measurement elements on the radial beam 400.

[0028] Please see Figures 1 to 2 In an optional embodiment of the present invention, a second strain hole 510 or a second strain groove 520 is provided on the support beam 500 and located at the end of the support beam 500 near the loading part 200. Its design, extending through the height direction, selectively weakens the cross-section of this local area without significantly affecting the main bending stiffness of the support beam 500. This optimizes the impact of this area on measurement sensitivity when subjected to loads (radial forces Fx, Fy, and torque Mz), effectively balancing the contradiction between the overall stiffness increase brought about by increasing the support beam 500 and the local measurement sensitivity requirements. When the sensor is subjected to torque around the axial direction (Z-axis), torsional deformation occurs at the root of the support beam 500, and significant shear strain concentration occurs on both sides of the second strain hole 510 or the second strain groove 520. By precisely designing the size and position of the second strain hole 510 or the second strain groove 520, while ensuring that the support beam 500 provides sufficient stiffness support, its strain response sensitivity to axial force and torque can be finely adjusted, thereby achieving a synergy and balance between high stiffness support and high sensitivity measurement.

[0029] It is understood that the number of support beams 500 is not limited. For example, one or more support beams 500 can be set between two adjacent radial beams 400, and they are uniformly distributed axially with the radial beams 400. It should be noted that the support beams 500 serve as auxiliary stiffness elements to enhance the structural stiffness of the elastomer in a specific dimension. Their specific structure, such as cross-sectional dimensions, can be configured according to the sensor's range and the stiffness distribution requirements in each dimension. The independent adjustability of the support beam 500's dimensions also allows the elastomer's structure to flexibly adapt to various application requirements from small to large ranges, possessing extremely high engineering application value. By adjusting the size and position of the first strain hole 310 or first strain groove 320 on the circumferential beam 300 and the second strain hole 510 or second strain groove 520 on the support beam 500, the stiffness and sensitivity of the elastomer in each dimension can be balanced, ensuring the isotropic measurement of the sensor. In other embodiments, when the overall design of the radial beams 400 and the circumferential beams 300 meets the performance requirements, the support beams 500 may not be provided.

[0030] Please see Figures 1 to 2In an optional embodiment of the present invention, radial force measuring elements are provided on the two side planes corresponding to the first strain hole 310 or the first strain groove 320. The radial force measuring elements are arranged along the width direction of the circumferential beam 300, and axial force measuring elements are provided on the surface of the support beam 500. The axial force measuring elements are arranged along the height direction of the support beam 500. The strain measuring elements can be, for example, resistance strain gauges. The radial force measuring elements are precisely attached to the two side planes of the first strain hole 310 or the first strain groove 320 along the width direction of the circumferential beam 300. Since this location is the area where bending stress concentration is most significant, the bending strain caused by the radial force can be converted into resistance change with the highest efficiency, thereby obtaining a radial force measurement signal with a high signal-to-noise ratio. Specifically, for example, strain gauges for measuring the radial force component Fx are arranged on the circumferential beam 300 in the Y direction. On each of the two Y-direction circumferential beams 300 located in the positive and negative X-axis directions, a radial force measuring element is attached to both sides of the first strain hole 310 (or first strain groove 320), forming a Wheatstone full-bridge circuit for precise measurement of Fx. When the force Fx in the X-axis direction acts on the loading part 200, the circumferential beam 300 in the Y direction will undergo bending deformation along the X-axis direction, and the stress will concentrate on both sides of the first strain hole 310 (or first strain groove 320). Attaching the radial force measuring element at this location allows for precise capture of the strain caused by Fx, thereby accurately measuring the magnitude of Fx. Similarly, strain gauges for measuring the radial force component Fy are arranged on the circumferential beam 300 in the X direction. On the two X-direction circumferential beams 300 located in the positive and negative Y-axis directions, another Wheatstone full-bridge circuit is formed for precise measurement of Fy. This symmetrical, intersecting arrangement utilizes the stress concentration effect to position the strain gauges, improving measurement sensitivity. Due to the symmetry of the strain gauge positions, interference from other force / moment components can be eliminated, achieving better decoupling. Each Fx or Fy measurement typically requires four or eight strain gauges, forming a Wheatstone full-bridge circuit to achieve temperature compensation, decoupling, and improved measurement accuracy.

[0031] Please see Figures 1 to 2 In an optional embodiment of the present invention, the axial force measuring element is arranged on the surface of the support beam 500 and in its root region along the height direction of the support beam 500. When the axial force Fz acts on the sensor, the root of the support beam 500 (the end near the fixing part 100) generates the maximum bending strain. The strain gauge is attached to the side of the support beam 500 along the height direction, and its sensitive direction is consistent with the bending strain direction, allowing for sensitive detection of tensile and compressive strain caused by the axial force. This arrangement achieves physical separation of the measurement functions: radial force is sensitive to the slotted area on the circumferential beam 300, and axial force is sensitive to the root region of the support beam 500. The two are structurally independent, reducing mechanical coupling and electrical crosstalk between the two types of signals from the source, facilitating subsequent signal decoupling processing.

[0032] Please see Figures 1 to 2 In an optional embodiment of the present invention, a bending moment measuring element is provided on the surface of the radial beam 400, and the bending moment measuring element is arranged along the height direction of the radial beam 400. Torque measuring elements are provided on the two side planes corresponding to the second strain hole 510 or the second strain groove 520, and the torque measuring elements are arranged along the width direction of the support beam 500. The bending moment measuring element is arranged on the surface of the radial beam 400 along the height direction, preferably located in the root region of the radial beam 400 near the fixing part 100. When the sensor is subjected to bending moments Mx and My around the X-axis or Y-axis, the root of the radial beam 400 will generate the largest bending strain. Attaching the strain gauge along the height direction at this location can effectively capture the bending moment signal. The torque measuring element is attached to the two side planes of the second strain hole 510 or the second strain groove 520 along the width direction of the support beam 500. When a torque Mz around the Z-axis acts on the sensor, the largest shear strain will be generated at the edges of the second strain hole 510 or the second strain groove 520, especially on its two side sides. By setting the torque measurement point on the support beam 500 and utilizing the stress concentration effect formed by the slots, the torque measurement area is spatially separated from other force measurement areas. This allows for sufficiently high torque measurement sensitivity within a compact structure. Simultaneously, the radial beam 400 can be shorter, resulting in increased stiffness. This embodiment distributes the sensitive areas of radial force, axial force, bending moment, and torque to four different structural locations: the side of the slot in the circumferential beam 300, the side of the root of the support beam 500, the root of the radial beam 400, and the side of the slot in the support beam 500. This achieves physical spatial decoupling of the six-dimensional force signals on the elastic body, avoiding signal interference caused by all strain gauges crowding onto a single beam. Crosstalk between the measurement bridges is significantly reduced, and high-precision raw signals can be obtained without relying on extremely complex subsequent decoupling algorithms, improving the overall measurement accuracy and stability of the sensor.

[0033] Please see Figure 3In an optional embodiment of the present invention, the radial beam 400 includes an I-beam segment 410 disposed on one side near or away from the circumferential beam 300, and symmetrically arranged about the central radial plane and the central height plane of the radial beam 400. The I-beam segment 410 includes a mutually parallel upper flange and a lower flange, and a web connecting the upper flange and the lower flange. The cross-sectional characteristics of the I-beam make it highly efficient in terms of bending and shear resistance. In this embodiment, by integrating the I-beam segment 410 into the radial beam 400, it can typically be disposed at the end of the radial beam 400 away from the circumferential beam 300. The symmetrical arrangement about the two planes ensures the balance of mechanical response. The introduction of the I-beam segment 410 significantly enhances the bending stiffness of the radial beam 400 in the vertical plane, thereby improving the stiffness and natural frequency of the entire sensor under bending moment loads. Simultaneously, the I-shaped cross-section naturally decomposes the stress, with the upper and lower flanges primarily bearing the normal tensile and compressive stresses caused by the bending moment, while the web primarily bears the shear stress. This allows for the simultaneous but independent measurement of different force components (such as axial force and bending moment) on the same beam segment. The shear strain characteristics of the web region under axial force can be used to measure axial force, while the upper and lower surfaces of the flanges are the optimal locations for measuring bending strain. This structure, through optimization of the cross-sectional shape of a single beam, achieves the integration and separation of some mechanical functions. The strain gauges used to measure Mx, My, and Fz are independent, and the length of the radial beam 400 can be shortened, resulting in an increased natural frequency of the elastic body and improved dynamic response characteristics. This makes it particularly suitable for applications requiring higher structural compactness and stiffness.

[0034] Please see Figure 3In an optional embodiment of the present invention, an axial force measuring element is provided on the side of the web of the I-beam segment 410. The axial force measuring element forms a 45° angle with the neutral axis of the I-beam segment 410. A bending moment measuring element is provided on the upper surface of the upper flange and the lower surface of the lower flange of the I-beam segment 410, and is located at the center line of the upper surface of the upper flange and the lower surface of the lower flange. A radial force measuring element is provided on the two side planes corresponding to the first strain hole 310 or the first strain groove 320. The radial force measuring element is arranged along the width direction of the circumferential beam 300. The axial force measuring element is attached to both sides of the web of the I-beam segment 410, at a 45° angle to the neutral axis of the web (i.e., the centerline in the height direction). When the axial force acts on the sensor, the web of the I-beam segment 410 mainly bears shear stress. In the pure shear stress state, there are principal tensile and principal compressive stresses in the direction at a 45° angle to the axis. Therefore, attaching the strain gauge along the 45° direction can most effectively detect the shear strain caused by the axial force, thereby achieving high sensitivity and low coupling measurement of the axial force. The bending moment measuring element is attached along the height direction of the radial beam 400 on the centerline of the upper surface of the upper flange and the centerline of the lower surface of the lower flange of the I-beam segment 410. When the bending moment acts on the sensor, the I-beam bends, and the upper and lower surfaces of the flange bear the maximum tensile and compressive stresses, respectively. Attaching the strain gauge at this location can most directly and effectively capture the bending strain signal. The radial force measurement is still completed by strain gauges arranged on both sides of the first strain hole 310 or the first strain groove 320 of the circumferential beam 300. Utilizing the mechanical properties of an I-beam cross-section, the axial force and bending moment measurement areas can be separated on the I-beam segment 410 of a single radial beam 400 (axial force is measured at 45° in the web direction, and bending moment is measured on the upper and lower surfaces of the flanges). This, combined with the radial force measurement area on the circumferential beam 300, forms a complete multi-dimensional force measurement network. Even without an independent supporting beam 500, good signal spatial separation is still achieved.

[0035] Specifically, when a moment Mx is applied in the X-axis direction, the radial beam 400 in the Y-axis direction will undergo bending deformation. The upper surface of the upper flange and the lower surface of the lower flange of its I-beam segment 410 will bear a large normal stress. By attaching a moment measuring element at this location, the strain caused by Mx can be accurately captured, thus accurately measuring the magnitude of Mx. Similarly, when a moment My is applied in the Y-axis direction, the radial beam 400 in the X-axis direction will undergo bending deformation. The upper surface of the upper flange and the lower surface of the lower flange of its I-beam segment 410 will also generate a large normal stress. By attaching a moment measuring element at this location, the magnitude of My can be accurately measured. Each measurement of Mx or My typically requires four strain gauges to form a Wheatstone full-bridge circuit. Utilizing the special structure of the I-beam, the decoupled measurement of Mx and My is effectively achieved.

[0036] Please see Figure 4In another optional embodiment of the invention, at least one pair of third strain holes 420 are provided on the radial beam 400, extending through its width direction. The third strain holes 420 are symmetrically arranged about the center height plane of the radial beam 400. The third strain holes 420 extend through the width direction of the radial beam 400 and are symmetrically arranged about the center plane of the thickness direction (height direction) of the radial beam 400. The horizontal through-hole design creates a local strain-sensitive region on the radial beam 400. When the sensor is subjected to axial force or radial bending moment, the radial beam 400 will undergo bending or tensile / compressive deformation. The horizontally arranged third strain holes 420 alter the stress distribution in their surrounding area, generating stress concentration at the upper and lower edges of the holes (along the height direction of the radial beam 400). This stress concentration effect can amplify the micro-strain in this region, thereby improving the measurement sensitivity. The symmetrical arrangement ensures a symmetrical strain response under tension and compression, which is beneficial for forming a differential bridge to eliminate common-mode interference and improve output. This structure is simpler and easier to manufacture than the I-beam segment 410, making it suitable for applications requiring a specific trade-off between sensitivity and manufacturing costs. The third strain gauge 420 can be circular, elliptical, or oblong, or it can be a horizontal double-through-hole formed by two parallel cylindrical through-holes connected to each other in a horizontal plane, to optimize stress concentration.

[0037] Please see Figure 4 In an optional embodiment of the present invention, an axial force measuring element is provided on the radial beam 400, which is arranged on both sides of the third strain gauge 420 along the height direction of the radial beam 400; a bending moment measuring element is also arranged on both sides of the third strain gauge 420 along the height direction of the radial beam 400. Radial force measuring elements are provided on the corresponding sides of the first strain gauge 310 or the first strain groove 320, and these radial force measuring elements are arranged along the width direction of the circumferential beam 300. The two sides of the third strain gauge 420 refer to the upper and lower surfaces along the height direction of the radial beam 400. The axial force measuring element and the bending moment measuring element are arranged in different regions of these planes along the height direction of the radial beam 400. By connecting the strain gauges at different positions in a specific manner to form a Wheatstone full-bridge circuit, the difference in their output signals can be used to separate the axial force (Fz) and bending moment (Mx, My) signals. The measurement of the radial force is still independently handled by the strain gauges on the circumferential beam 300. Thus, even on the relatively simple radial beam 400, multiple force components can be independently measured by combining the third strain gauge 420 with a bridge design.

[0038] Specifically, when a torque Mx is applied in the X-axis direction, the radial beam 400 in the Y-axis direction will undergo bending deformation, with strain concentrated on the upper and lower surfaces of its third strain gauge 420. By attaching a moment measuring element at this location, the strain caused by Mx can be accurately captured, thus accurately measuring the magnitude of Mx. Similarly, when a torque My is applied in the Y-axis direction, the radial beam 400 in the X-axis direction will undergo bending deformation, with strain concentrated on the upper and lower surfaces of its third strain gauge 420. By attaching a moment measuring element at this location, the magnitude of My can be accurately measured. Each measurement of Mx or My typically requires four strain gauges, forming a Wheatstone full-bridge circuit. The strain gauges for Fz and Mx / My can be arranged separately by differentiating the position of the third strain gauge 420 near or far from the circumferential beam 300. This differentiated placement design allows for effective decoupling of the measurement of these force / moment components.

[0039] Please see Figures 3 to 5 In an optional embodiment of the present invention, a fourth strain gauge hole 430 extending along its height direction is further provided on the radial beam 400. The fourth strain gauge hole 430 is an elliptical hole, a waist-shaped hole, or a rectangular hole. When the radial beam 400 is provided with an I-beam segment 410 or a third strain gauge hole 420, the fourth strain gauge hole 430 can be located on the side of the radial beam 400 away from the I-beam segment 410 or the third strain gauge hole 420. Furthermore, the long axis direction of this hole is generally consistent with the width direction of the radial beam 400, which can provide an optimized sensitive area for torque measurement. When the sensor is subjected to a torque about the axial direction, the radial beam 400 will undergo torsional deformation. The presence of the fourth strain gauge hole 430, especially its elliptical or waist-shaped shape, can generate significant shear stress concentration in the regions on both sides along its width direction. This structure can effectively concentrate the shear strain caused by the torque to specific regions on both sides of the hole, thereby improving the sensitivity and signal-to-noise ratio of torque Mz measurement. Furthermore, since its major axis is aligned with the width of the radial beam 400, the key features of this through-hole as a local strain concentration area, such as its minor axis dimension, remain relatively independent. When adjusting the dimensions of the radial beam 400 to meet overall stiffness or range requirements, the dimensions of this hole can be optimized relatively independently to finely adjust the strain concentration coefficient and measurement sensitivity of this local area without worrying about drastic and uncontrollable changes in the feasibility of the hole's construction or stress concentration effect due to changes in the main beam dimensions. This provides greater flexibility and convenience for subsequent structural optimization and parameter adjustment, making it easier to achieve optimal performance during the design phase, and offering more flexible optimization space and stronger engineering adaptability.

[0040] Please see Figures 3 to 5In an optional embodiment of the present invention, torque measuring elements are disposed on the two side planes corresponding to the fourth strain gauge 430, and the torque measuring elements are arranged along the width direction of the radial beam 400. The torque measuring elements are attached to the two side planes of the fourth strain gauge 430 along the width direction of the radial beam 400. When a torque load is applied to the sensor, the radial beam 400 deforms, generating strains in opposite directions on both sides of the fourth strain gauge 430. By attaching strain gauges along the width direction of the radial beam 400, this strain change can be directly and efficiently sensed. By connecting the strain gauges at corresponding positions on multiple radial beams 400 into a differential bridge, the torque signal can be effectively extracted and interference from other force components (such as axial force and bending moment) can be suppressed.

[0041] In summary, the multidimensional force measurement device provided by this invention lays the foundation for high-sensitivity, isotropic radial force measurement by designing the core sensing structure beam body and the first strain holes 310 or first strain grooves 320 arranged in a specific and symmetrical direction, and significantly improves the manufacturability. By adding the support beam 500 structure, the contradiction between high-rigidity support and high-sensitivity measurement is resolved, and the physical spatial decoupling of the measurement signal on the circumferential beam 300, radial beam 400 and support beam 500 is realized, greatly reducing interdimensional coupling. The size, position and hole and groove features of the support beam 500 can be designed independently, and various radial beam 400 variant structures including I-beam segment 410, third strain hole 420, and fourth strain hole 430 are provided. Combined with a detailed strain measurement element layout scheme, a complete, flexible and scalable system is formed. It can flexibly adapt to various differentiated application requirements from small range to large range, from static precision measurement to dynamic high-speed response through parameter adjustment, and solve multiple contradictions between stiffness and sensitivity, accuracy and crosstalk, performance and manufacturability.

[0042] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

[0043] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the invention. However, those skilled in the art will recognize that embodiments of the invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention.

[0044] Throughout this specification, the terms "an embodiment," "embodiment," or "specific embodiment" refer to a particular feature, structure, or characteristic described in connection with an embodiment that is included in at least one embodiment of the invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the invention.

[0045] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0046] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0047] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0048] The above description of the embodiments shown in this invention (including the content set forth in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the invention to the precise forms disclosed herein. Although specific embodiments and examples of the invention have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the invention, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the invention in accordance with the above description of the embodiments described herein, and such modifications will be within the spirit and scope of the invention.

[0049] This document has generally described the systems and methods in detail to aid in understanding the invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the invention. However, those skilled in the art will recognize that embodiments of the invention can be practiced without one or more specific details, or using other means, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention.

[0050] Therefore, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the scope of the foregoing disclosure, and it should be understood that in some cases, certain features of the invention may be adopted without departing from the scope and spirit of the invention and without corresponding use of other features. Thus, many modifications can be made to adapt a particular environment or material to the essential scope and spirit of the invention. The invention is not intended to be limited to the specific terminology used in the following claims and / or the specific embodiments disclosed as the best mode for carrying out the invention, but the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Therefore, the scope of the invention will be defined only by the appended claims.

Claims

1. A multidimensional force measuring device, characterized in that, The system includes a fixed part, a loading part, and a composite beam structure connected between them, all arranged coaxially. The composite beam structure includes a beam body, which includes a circumferential beam and a radial beam arranged radially. One end of the radial beam is perpendicularly connected to the center of the circumferential beam, and the other end is connected to the fixed part or the loading part. On the circumferential beam, corresponding to the connection position of each radial beam, at least one pair of first strain holes or first strain grooves penetrating along its height direction are provided. The first strain hole is symmetrical about the centerline of the circumferential beam in the width direction and the central radial plane of the corresponding radial beam, and the major axis of the first strain hole is consistent with the length direction of the circumferential beam. The first strain groove is symmetrical about the centerline of the circumferential beam in the width direction and the central radial plane of the corresponding radial beam, and its extension direction is consistent with the length direction of the circumferential beam.

2. The multidimensional force measuring device according to claim 1, characterized in that, The beam body includes a support beam disposed between adjacent radial beams, one end of the support beam being connected to the fixing part and the other end being connected to the loading part; The support beam is provided with a second strain hole or a second strain groove extending through its height at one end where it is connected to the loading part. The second strain hole or the second strain groove is arranged symmetrically about the central radial plane of the support beam.

3. The multidimensional force measuring device according to claim 2, characterized in that, Radial force measuring elements are provided on both sides of the first strain hole or the first strain groove. The radial force measuring elements are arranged along the width direction of the circumferential beam. An axial force measuring element is provided on the surface of the support beam. The axial force measuring element is arranged along the height direction of the support beam.

4. The multidimensional force measuring device according to claim 3, characterized in that, A bending moment measuring element is provided on the surface of the radial beam, and the bending moment measuring element is arranged along the height direction of the radial beam. Torque measuring elements are provided on the two side planes corresponding to the second strain hole or the second strain groove, and the torque measuring elements are arranged along the width direction of the support beam.

5. The multidimensional force measuring device according to claim 1, characterized in that, The radial beam includes an I-beam segment disposed on one side near or away from the circumferential beam and symmetrically arranged about the central radial plane and the central height plane of the radial beam. The I-beam segment includes an upper flange and a lower flange that are parallel to each other, and a web connecting the upper flange and the lower flange.

6. The multidimensional force measuring device according to claim 5, characterized in that, An axial force measuring element is provided on the side of the web of the I-beam segment. The axial force measuring element is at a 45° angle to the neutral axis of the I-beam segment. A bending moment measuring element is provided on the upper surface of the upper flange and the lower surface of the lower flange of the I-beam segment, and is located at the center line of the upper surface of the upper flange and the lower surface of the lower flange. Radial force measuring elements are provided on the two side planes corresponding to the first strain hole or the first strain groove, and the radial force measuring elements are arranged along the width direction of the circumferential beam.

7. The multidimensional force measuring device according to claim 1, characterized in that, At least one pair of third strain holes are provided on the radial beam, extending through its width direction. The third strain holes are arranged symmetrically about the center height plane of the radial beam.

8. The multidimensional force measuring device according to claim 7, characterized in that, The radial beam is also provided with an axial force measuring element, which is arranged on both sides of the third strain hole along the height direction of the radial beam, and a bending moment measuring element, which is arranged on both sides of the third strain hole along the height direction of the radial beam. Radial force measuring elements are provided on the two side planes corresponding to the first strain hole or the first strain groove, and the radial force measuring elements are arranged along the width direction of the circumferential beam.

9. The multidimensional force measuring device according to claim 6 or 8, characterized in that, A fourth strain hole is provided on the radial beam, which extends through the beam along its height direction. The fourth strain hole is an elliptical hole, a waist-shaped hole, or a rectangular hole.

10. The multidimensional force measuring device according to claim 9, characterized in that, Torque measuring elements are provided on the two planes corresponding to the fourth strain hole, and the torque measuring elements are arranged along the width direction of the radial beam.

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