Wideband-domain six-dimensional force sensor, broadband design and use method

Abstract

The invention belongs to the technical field of multi-dimensional force sensors, and particularly relates to a wide-frequency-domain six-dimensional force sensor and a broadband design and use method.The sensor comprises an upper connecting platform and a lower connecting platform which are coaxially arranged, and the upper connecting platform and the lower connecting platform are connected through composite measuring branches arranged at equal intervals in the circumferential direction; the composite measurement branch is electrically connected with a signal amplification device; the signal amplification device is arranged between the upper connection platform and the lower connection platform; the composite measuring branch is of a V-shaped structure, a piezoelectric assembly and a sensitive strain structure are arranged in the composite measuring branch, the piezoelectric assembly is arranged close to the upper connecting platform, the sensitive strain structure is arranged close to the lower connecting platform, and the piezoelectric assembly and the sensitive strain structure are connected through a decoupling structure; the decoupling structure comprises a first decoupling structure and a second decoupling structure, and the sensitive strain structure is connected between the small end face of the second decoupling structure and the first decoupling structure. The invention further discloses a design and use method of the sensor.

Description

Technical Field

[0001] The present invention belongs to the technical field of multi-dimensional force sensors, and particularly relates to a broadband six-dimensional force sensor, a broadband design and a usage method. Background Art

[0002] With the development of robot technology, the demand for high-precision and high-reliability force perception of humanoid robots is becoming increasingly urgent. The six-dimensional force sensor has become the most important force perception component of humanoid robots because it can effectively provide real-time and complete spatial force / moment information.

[0003] When the six-dimensional force sensor serves in the daily operations of humanoid robots, such as in the fields of handling, assembly, grinding, etc., it often faces harsh environmental conditions such as vibration, shock, and collision. Therefore, in addition to having the ability to detect conventional continuous loads (with frequencies from a few to several hundred hertz), the six-dimensional force sensor should also be able to accurately detect high-frequency and transient loads (with frequencies from several hundred hertz to several tens of kilohertz).

[0004] According to the measurement principle, six-dimensional force sensors are mainly divided into strain type, piezoelectric type, capacitive type, optical type, and magnetostrictive type. The strain-type six-dimensional force sensor has the most mature technology and has become the most widely used type of six-dimensional force sensor due to its good low-frequency characteristics and excellent static measurement performance. However, it is limited by the natural frequency of the elastic body and the response speed of the strain gauge and cannot accurately measure high-frequency impacts and vibrations. The piezoelectric six-dimensional force sensor, on the other hand, has become the first choice for measuring high-frequency impacts and vibrations due to its fast high-frequency response and excellent dynamic measurement performance. However, the charge of the piezoelectric material will dissipate over time and the low-frequency signal is easily interfered by the noise of the charge amplifier. Therefore, it cannot accurately measure low-frequency continuous loads. The capacitive six-dimensional force sensor can detect displacements at the nanometer level and has high resolution, but it is also limited by the mechanical resonance frequency of the structure and cannot accurately measure high-frequency impacts and vibrations. The optical six-dimensional force sensor has excellent anti-electromagnetic interference performance, but there is serious high-frequency signal aliasing and it cannot accurately measure high-frequency impacts and vibrations. The magnetostrictive type has extremely excellent load-bearing capacity, but due to the response hysteresis of the magnetic material, there is also a serious problem of high-frequency signal aliasing and it cannot accurately measure high-frequency impacts and vibrations.

[0005] Therefore, how to meet the high-precision force perception requirements of humanoid robots during low-frequency and high-frequency operations and design a broadband six-dimensional force sensor has become an urgent technical problem to be solved. Summary of the Invention

[0006] The purpose of the present invention is to provide a broadband six-dimensional force sensor, a broadband design and a usage method to solve the above problems.

[0007] To achieve the above purpose, the present invention provides the following solutions:

[0008] A broadband six-dimensional force sensor, comprising:

[0009] An upper connection platform and a lower connection platform are coaxially arranged. The upper connection platform and the lower connection platform are connected by composite measurement branches arranged at equal intervals in the circumferential direction. The composite measurement branches are electrically connected to a signal amplification device, and the signal amplification device is arranged between the upper connection platform and the lower connection platform;

[0010] The composite measurement branch has a V-shaped structure. A piezoelectric component and a sensitive strain structure are arranged inside the composite measurement branch. The piezoelectric component is arranged close to the upper connection platform, and the sensitive strain structure is arranged close to the lower connection platform. The piezoelectric component and the sensitive strain structure are connected by a decoupling structure;

[0011] The decoupling structure includes a decoupling structure one and a decoupling structure two. The decoupling structure one has two layers of I-shaped structures, and the included angle between the straight lines where the webs of the two layers of I-shaped structures are located is 90°;

[0012] The decoupling structure two is a wedge-shaped prism. The decoupling structure two has three self-rotation axes that are perpendicular to each other and share an intersection point. The large end face of the decoupling structure two is connected to the lower connection platform, and the sensitive strain structure is connected and arranged between the small end face of the decoupling structure two and the decoupling structure one.

[0013] Optionally, the composite measurement branch includes an upper connection seat. The upper connection seat has a V-shaped structure. The first end of the upper connection seat is fixed to the upper connection platform. One ends of vibration isolators are fixedly connected to the second end and the third end of the upper connection seat respectively, and the other ends of the vibration isolators are fixedly connected to one ends of the corresponding decoupling structure one;

[0014] The other end of the decoupling structure one is fixedly connected to one end of the corresponding sensitive strain structure. The other end of the sensitive strain structure is fixedly connected to the small end face of the decoupling structure two. One end of a lower connection seat is fixedly connected to the large end face of the decoupling structure two, and the other end of the lower connection seat is fixedly connected to the lower connection platform;

[0015] The piezoelectric component is embedded and fixed in the upper connection seat.

[0016] Optionally, the vibration isolator includes a support column body. One side of the support column body is fixedly connected to the second end / third end of the upper connection seat, and the other side of the support column body is fixedly connected to the decoupling structure one. Flexible silicone damping bodies are filled between the support column body and the second end / third end of the upper connection seat, and between the support column body and the decoupling structure one.

[0017] Optionally, a plurality of force application holes are provided at equal intervals in the circumferential direction on the top of the upper connection platform, and two positioning pin holes 1 are provided on the top of the upper connection platform. The included angle between the two positioning pin holes 1 and the center line of the top of the upper connection platform is 90°.

[0018] Optionally, a plurality of mounting holes are provided at equal intervals in the circumferential direction on the bottom of the lower connection platform, and two positioning pin holes 2 are provided on the bottom of the lower connection platform. The included angle between the two positioning pin holes 2 and the center line of the bottom of the lower connection platform is 90°.

[0019] Optionally, the piezoelectric component includes:

[0020] Mounting cabins, which are provided on the upper connection seat and are symmetrically arranged in two;

[0021] A single-dimensional force-sensing crystal group composed of several stacked cut-type quartz wafers, which is installed in the mounting cabin;

[0022] A cover, which is sleeved outside the single-dimensional force-sensing crystal group. The cover is used to fix the single-dimensional force-sensing crystal group in the mounting cabin, and the cover and the mounting cabin are fixed by pre-tightening screws.

[0023] Optionally, the signal amplification device includes a piezoelectric acquisition and amplification device and a strain acquisition and amplification device. The piezoelectric acquisition and amplification device is fixed on the upper connection platform and is electrically connected to the piezoelectric component. The strain acquisition and amplification device is fixed on the lower connection platform and is electrically connected to the sensitive strain structure.

[0024] Optionally, the sensitive strain structure includes parallel beams. The parallel beams are hollow structures, strain gauges are pasted on the top and bottom walls of the inner cavity of the parallel beams, and a bridge-forming plate is fixedly connected to the outer wall surface of the parallel beams;

[0025] The parallel beam is composed of two cross beams and two vertical beams to form a rectangular frame structure. The strain gauges are fixed on the inner walls of the cross beams, the bridge-forming plate is fixedly connected to the outer walls of the vertical beams, and two semicircular removal grooves are provided on the outer walls of the vertical beams. The bridge-forming plate is located between the two semicircular removal grooves.

[0026] A design method for a broadband six-dimensional force sensor, which is used for the above-mentioned broadband six-dimensional force sensor, includes the following steps:

[0027] Taking the ratio of the upper limit value of the strain channel bandwidth to the lower limit value of the piezoelectric channel bandwidth being greater than 1 as the optimization goal;

[0028] Obtaining the main structural parameters of the composite measurement branch, the upper connection platform, and the lower connection platform;

[0029] Set the optimization constraint conditions for the composite measurement branch, the upper connection platform, and the lower connection platform;

[0030] Model based on the main structural parameters and analyze the model to obtain optimization data;

[0031] Obtain the final design parameters according to the optimization data, and fabricate the broadband six - dimensional force sensor according to the final design parameters.

[0032] A usage method of a broadband six - dimensional force sensor, which is used for the above - mentioned broadband six - dimensional force sensor, includes the following steps:

[0033] Take the lower limit value of the piezoelectric channel bandwidth as the low - pass filter cut - off frequency of the strain acquisition and amplification device, and take the upper limit value of the strain channel bandwidth as the high - pass filter cut - off frequency of the piezoelectric acquisition and amplification device to design the amplification device;

[0034] Obtain the measured values of the strain channel and the piezoelectric channel through conventional calibration and decoupling;

[0035] Design the regulation function with the external load frequency as a parameter, and set the weight coefficients of the static output force of the strain channel and the dynamic output force of the piezoelectric channel based on the regulation function;

[0036] Set the fusion output of the measured values of the strain channel and the piezoelectric channel with the weight coefficients as the distribution ratio.

[0037] Compared with the prior art, the present invention has the following advantages and technical effects:

[0038] Compared with the traditional technology, the six - dimensional force sensor designed by the present invention has a highly symmetric parallel structure, and the force mapping relationship is clear and easy to solve. The piezoelectric component is located in the upper connection seat with high stiffness. The strain gauge is located on the parallel beam with low stiffness, between the vibration isolator, decoupling structure one, and decoupling structure two. The vibration isolator, decoupling structure one, and decoupling structure two form a double - ball - hinge structure, which not only has the function of structural decoupling but also can fully absorb the interference of high - frequency vibration on the static strain signal. Cooperating with the modular - designed amplification device, the compactness of the six - dimensional force sensor is realized, forming a dual - measurement state where the piezoelectric component has a good high - frequency dynamic measurement environment and the strain gauge has a stable and good low - frequency static measurement environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings:

[0040] Figure 1Top view of a broadband six - dimensional force sensor disclosed by the present invention;

[0041] Figure 2 Bottom view of a broadband six - dimensional force sensor disclosed by the present invention;

[0042] Figure 3 Position definition diagram of the composite measurement branch of a broadband six - dimensional force sensor disclosed by the present invention on the upper and lower connection platforms;

[0043] Figure 4 Schematic diagram of the local structure of the composite measurement branch of a broadband six - dimensional force sensor disclosed by the present invention Figure 1 ;

[0044] Figure 5 Schematic diagram of the local structure of the composite measurement branch of a broadband six - dimensional force sensor disclosed by the present invention Figure 2 ;

[0045] Figure 6 Main structure schematic diagram of the piezoelectric component of a broadband six - dimensional force sensor disclosed by the present invention;

[0046] Figure 7 Vibration isolation structure schematic diagram of a broadband six - dimensional force sensor disclosed by the present invention;

[0047] Figure 8 Broadband design method flow of a broadband six - dimensional force sensor disclosed by the present invention;

[0048] Among them, 1. Upper connection platform; 11. Force application hole; 12. Positioning pin hole 1; 2. Lower connection platform; 21. Mounting hole; 22. Positioning pin hole 2; 3. Composite measurement branch; 31. Upper connection seat; 32. Lower connection seat; 33. Piezoelectric component; 331. Single - dimensional force - measuring crystal group; 332. Sealing cover; 333. Pre - tightening screw; 334. Installation cabin; 34. Vibration isolation body; 341. Support column; 342. Flexible silicone damping body; 35. Decoupling structure 1; 36. Sensitive strain structure; 361. Parallel beam; 3611. Cross beam; 3612. Vertical beam; 3613. Semi - circular removal groove; 362. Strain gauge; 363. Group - bridge plate; 37. Decoupling structure 2; 4. Piezoelectric acquisition and amplification device; 5. Strain acquisition and amplification device. Detailed implementation manners

[0049] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] Refer to Figures 1 to 8 , the present invention discloses a broadband six-dimensional force sensor, including:

[0052] An upper connection platform 1 and a lower connection platform 2 arranged coaxially, the upper connection platform 1 and the lower connection platform 2 are connected by a plurality of composite measurement branches 3 arranged at equal intervals circumferentially, and the composite measurement branches 3 are electrically connected to a signal amplification device, and the signal amplification device is arranged between the upper connection platform 1 and the lower connection platform 2;

[0053] The composite measurement branch 3 has a V-shaped structure, and a piezoelectric component 33 and a sensitive strain structure 36 are arranged inside the composite measurement branch 3. The piezoelectric component 33 is arranged close to the upper connection platform 1, and the sensitive strain structure 36 is arranged close to the lower connection platform 2. The piezoelectric component 33 and the sensitive strain structure 36 are connected by a decoupling structure;

[0054] The decoupling structure includes a decoupling structure one 35 and a decoupling structure two 37. The decoupling structure one 35 has two layers of I-shaped structures, and the included angle between the straight lines where the webs of the two layers of I-shaped structures are located is 90°;

[0055] The decoupling structure two 37 is a wedge-shaped prism, which has three mutually perpendicular and collinear self-rotation axes. The large end face of the decoupling structure two 37 is connected to the lower connection platform 2, and the sensitive strain structure 36 is connected and arranged between the small end face of the decoupling structure two 37 and the decoupling structure one 35.

[0056] Compared with the traditional technology, the six-dimensional force sensor designed by the present invention is a highly symmetric parallel structure, and the force mapping relationship is clear and easy to solve. The piezoelectric component 33 is located in the upper connection seat 31 with high stiffness. The strain gauge 362 is on the parallel beam 361 with low stiffness, and is located between the vibration isolation body 34, the decoupling structure one 35 and the decoupling structure two 37. The vibration isolation body 34, the decoupling structure one 35 and the decoupling structure two 37 form a double ball hinge structure, which not only has the function of structural decoupling but also can fully absorb the interference of high-frequency vibration on the static strain signal and realize the compactness of the six-dimensional force sensor. At the same time, the piezoelectric component has a good high-frequency dynamic measurement environment, and the strain gauge also has a stable and good low-frequency static measurement environment.

[0057] A broadband six-dimensional force sensor provided by the present invention includes: an upper connection platform 1, a lower connection platform 2, a plurality of composite measurement branches 3 and a signal amplification device.

[0058] The lower connection platform 2 is arranged below the upper connection platform 1.

[0059] A plurality of composite measurement branches 3 are fixedly installed between the upper connection platform 1 and the lower connection platform 2.

[0060] Further, both the upper connection platform 1 and the lower connection platform 2 are cylinders with an annular cross-section and have comparable dimensions.

[0061] As an alternative implementation, the composite measurement branch 3 includes an upper connection seat 31. The upper connection seat 31 has a V-shaped structure. The first end of the upper connection seat 31 is fixed to the upper connection platform 1. Both the second end and the third end of the upper connection seat 31 are fixedly connected to one end of the vibration isolation body 34. The other end of the vibration isolation body 34 is fixedly connected to one end of the corresponding decoupling structure 1 35.

[0062] The other end of the decoupling structure 1 35 is fixedly connected to one end of the corresponding sensitive strain structure 36. The other end of the sensitive strain structure 36 is fixedly connected to the small end face of the decoupling structure 2 37. The large end face of the decoupling structure 2 37 is fixedly connected to one end of the lower connection seat 32. The other end of the lower connection seat 32 is fixedly connected to the lower connection platform 2.

[0063] The piezoelectric component 33 is embedded in the upper connection seat 31.

[0064] Further, a plurality of composite measurement branches 3 are installed between the upper connection platform 1 and the lower connection platform 2. Refer to Figure 3 , the connection position points of the V-shaped branches of the composite measurement branch 3 with the upper connection platform 1 are u1, u2, u3, u4, u5, u6, and the connection position points are located on the same positioning circle line. The radius of the positioning circle is R2. The included angle between the two connection lines formed by the two position points on the same V-shaped branch connected to the upper connection platform 1 and the center point of the top surface of the upper connection platform 1 is the positioning angle The connection position points of the V-shaped branches of the composite measurement branch 3 with the lower connection platform 2 are U1, U2, U3, U4, U5, U6, and the connection position points are located on the same positioning circle line. The radius of the positioning circle is R1. The included angle between the two connection lines formed by the two position points on the same V-shaped branch connected to the bottom surface of the lower connection platform 2 and the center point of the lower connection platform 2 is the positioning angle The distance between the upper and lower connection platforms is H c , and the composite measurement branches 3 are evenly connected between the upper connection platform 1 and the lower connection platform 2.

[0065] Specifically, during use, the position definition of the composite measurement branch 3 performed by the above method facilitates the calculation of the position and force mapping relationship of the composite measurement branch 3.

[0066] Further, the decoupling structure 2 37 is a wedge-shaped prism with three mutually perpendicular and co-intersecting self-rotation axes. The small end face of the wedge-shaped prism 37 is connected to the lower end face of the sensitive strain structure 36, and the large end face is connected to the lower connection seat 32.

[0067] Specifically, during use, the decoupling structure two 37 can provide the composite measurement branch 3 with three rotational degrees of freedom that are perpendicular to each other and share an intersection point along the axes.

[0068] As an alternative implementation, the vibration isolation body 34 includes a support column 341. One side of the support column 341 is fixedly connected to the second end / third end of the upper connecting seat 31, and the other side of the support column 341 is fixedly connected to the decoupling structure one 35. Flexible silicone damping bodies 342 are filled between the support column 341 and the second end / third end of the upper connecting seat 31, and between the support column 341 and the decoupling structure one 35.

[0069] Furthermore, the composite measurement branch 3 includes an upper connecting seat 31, a lower connecting seat 32, a piezoelectric component 33, a vibration isolation body 34, a decoupling structure one 35, a sensitive strain structure 36, and a decoupling structure two 37.

[0070] One end of the upper connecting seat 31 is connected to the upper connecting platform 1, and the other end is connected to the vibration isolation body 34; the piezoelectric component 33 is embedded in the upper connecting seat 31; the decoupling structure one 35 is arranged on the side of the vibration isolation body 34 away from the upper connecting seat 31; the sensitive strain structure 36 is arranged on the side of the decoupling structure one 35 away from the upper connecting seat 31; the decoupling structure two 37 is arranged at the lower end of the sensitive strain structure 36 away from the upper connecting seat 31 and is connected to the lower connecting seat 32; the lower connecting seat 32 is arranged on the lower connecting platform 2.

[0071] Specifically, during use, the force is transmitted from the upper connecting platform 1 to the upper connecting seat 31. The upper connecting seat 31 undergoes tensile and compressive deformation, forcing the piezoelectric component 33 to generate a piezoelectric effect. The generated electrical signal is processed by the piezoelectric acquisition and amplification device 4 and transmitted to the host computer. At the same time, the force is transmitted from the upper connecting seat 31 to the vibration isolation body 34, the decoupling structure one 35, the sensitive strain structure 36, and the decoupling structure two 37 in sequence, and finally transmitted to the lower connecting platform 2 through the lower connecting seat 32. When the force is transmitted to the sensitive strain structure 36, it causes tensile and compressive deformation, and then is processed by the signal amplification device and transmitted to the host computer, completing the measurement of the piezoelectric and strain dual-channel signals.

[0072] Furthermore, the upper end of the upper connecting seat 31 is connected to the lower end face of the upper connecting platform 1, and the lower end face of the upper connecting seat 31 is connected to the upper end face of the vibration isolation body 34. The upper connecting seat 31 is in an inverted V shape, with a rectangular cross-section and a volume much larger than that of the vibration isolation body 34, the decoupling structure one 35, the sensitive strain structure 36, and the decoupling structure two 37.

[0073] Specifically, during use, through the above structural design, it is used to provide a high-stiffness measurement environment for the piezoelectric component 33.

[0074] Further, the upper end surface of the vibration isolator 34 is connected to the lower end of the upper connection base 31, and the lower end surface is connected to the upper end surface of the decoupling structure 1 35. The vibration isolator 34 is composed of three-layer support columns 341 with a rectangular cross-section and a flexible silicone damping body 342 wrapped and adhered to the outer side surface of the support columns.

[0075] Specifically, during use, through the above structural design, the support columns 341 can provide a torsional degree of freedom for the composite measurement branch 3 along its axis direction. At the same time, combined with the flexible silicone damping body 342, it can fully absorb high-frequency vibrations and eliminate static strain measurement interference.

[0076] Further, the upper end surface of the decoupling structure 1 35 is connected to the lower end surface of the vibration isolator 34, and the lower end surface is connected to the upper end surface of the sensitive strain structure 36.

[0077] The decoupling structure 1 35 is a double-layer structure. Both the upper and lower layers are I-shaped structures, and the included angle between the straight lines where the webs of the two I-shaped structures are located is 90°.

[0078] Specifically, during use, through the above structural design, it is used to provide two rotational degrees of freedom with mutually perpendicular axes for the composite measurement branch 3, absorb the bending deformations generated in two mutually perpendicular directions within the plane perpendicular to the axis of the composite measurement branch 3, and assist in eliminating the interference of high-frequency vibrations on static strain measurement.

[0079] As an alternative implementation manner, a plurality of force application holes 11 are circumferentially and equally spaced on the top of the upper connection platform 1. Two positioning pin holes 1 12 are provided on the top of the upper connection platform 1, and the included angle between the two positioning pin holes 1 12 and the center line of the top of the upper connection platform 1 is 90°.

[0080] As an alternative implementation manner, a plurality of mounting holes 21 are circumferentially and equally spaced on the bottom of the lower connection platform 2. Two positioning pin holes 2 22 are provided on the bottom of the lower connection platform 2, and the included angle between the two positioning pin holes 2 22 and the center line of the bottom of the lower connection platform 2 is 90°.

[0081] Twelve force application holes 11 and two positioning pin holes 1 12 are evenly distributed on the upper end surface of the upper connection platform 1. The two pin holes 12 are located on the concentric circles of the upper end surface of the upper connection platform 1 and the included angle is 90°, which is used to mark the X-axis and Y-axis directions of the upper end surface of the upper connection platform 1.

[0082] Twelve mounting holes 21 and two positioning pin holes 2 22 are evenly distributed on the lower end surface of the lower connection platform 2. The two pin holes 22 are located on the concentric circles of the lower end surface of the lower connection platform 2 and the included angle is 90°, which is used to mark the X-axis and Y-axis directions of the lower end surface of the lower connection platform 2.

[0083] Specifically, during use, through the design of connecting the upper connecting platform 1 and the lower connecting platform 2 on the circular cylindrical body with the same above-mentioned dimensions, it is used to provide a vertically symmetric and consistent structure for the sensor. The external force / moment acts on the upper connecting platform 1 through the force application hole 11 and is transmitted to the lower connecting platform 2, and then is transmitted out through the uniformly distributed mounting holes 21 on the lower end surface of the lower connecting platform 2, effectively realizing uniform force conduction.

[0084] As an alternative implementation, the piezoelectric component 33 includes:

[0085] The mounting compartments 334 are opened on the upper connecting seat 31, and there are two mounting compartments 334 which are symmetrically arranged;

[0086] The single-dimensional force-sensing crystal group 331 composed of several stacked cut-type quartz wafers is installed in the mounting compartment 334;

[0087] The cover 332 is sleeved outside the single-dimensional force-sensing crystal group 331. The cover 332 is used to fix the single-dimensional force-sensing crystal group 331 in the mounting compartment 334, and the cover 332 and the mounting compartment 334 are fixed by the pre-tightening screw 333.

[0088] The mounting compartments 334 of the piezoelectric component 33 are symmetrically arranged at the centers of the outer surfaces on both sides of the inverted V shape of the upper connecting seat 31.

[0089] Furthermore, the piezoelectric component 33 mainly consists of a single-dimensional force-sensing crystal group 331 composed of several xy (x0°) cut-type quartz wafers, a cylindrical structure cover 332 with a countersunk threaded hole, and a columnar mounting compartment 334. Electrodes are arranged on both sides of the x-axis of the single-dimensional force-sensing crystal group 331, and the y and z axes are designed as shielding layers. The pre-tightening screw 333 can install the single-dimensional force-sensing crystal group 331 in the mounting compartment 334 at the centers of the outer surfaces on both sides of the inverted V shape of the upper connecting seat 31 through the cover 332.

[0090] Specifically, during use, through the above-mentioned structural design, it is used to make the piezoelectric component 33 sensitive only in one direction and in a compressed state.

[0091] As an alternative implementation, the signal amplification device includes a piezoelectric acquisition and amplification device 4 and a strain acquisition and amplification device 5. The piezoelectric acquisition and amplification device 4 is fixed on the upper connecting platform 1 and is electrically connected to the piezoelectric component 33, and the strain acquisition and amplification device 5 is fixed on the lower connecting platform 2 and is electrically connected to the sensitive strain structure 36.

[0092] Furthermore, several piezoelectric acquisition and amplification devices 4 are uniformly installed on the lower end surface of the upper connecting platform 1, and several strain acquisition and amplification devices 5 are also uniformly installed on the upper end surface of the lower connecting platform 2. The piezoelectric acquisition and amplification device 4 and the strain acquisition and amplification device 5 have the same shell shape and equivalent mass.

[0093] Specifically, during use, when an external force is transmitted to the upper connection platform 1 and the lower connection platform 2 with high rigidity, the platforms only produce extremely small deformations, avoiding deformation of the piezoelectric acquisition and amplification device 4 and the strain acquisition and amplification device 5 housing, which may affect the normal operation of the measurement circuit and making the sensor structure compact.

[0094] As an alternative embodiment, the sensitive strain structure 36 includes parallel beams 361. The parallel beams 361 are hollow structures. Strain gauges 362 are pasted on the top and bottom walls of the inner cavity of the parallel beams 361, and a bridge-forming plate 363 is fixedly connected to the outer wall surface of the parallel beams 361.

[0095] As an alternative embodiment, the parallel beam 361 is composed of two cross beams 3611 and two vertical beams 3612 to form a rectangular frame structure. The strain gauges 362 are fixed on the inner walls of the cross beams 3611, and the bridge-forming plate 363 is fixedly connected to the outer walls of the vertical beams 3612. Two semi-circular removal grooves 3613 are formed on the outer walls of the vertical beams 3612, and the bridge-forming plate 363 is located between the two semi-circular removal grooves 3613.

[0096] The strain gauges 362 are pasted inside the sensitive strain structure 36.

[0097] Furthermore, the sensitive strain structure 36 includes parallel beams 361 disposed between the decoupling structure one 35 and the decoupling structure two 37, strain gauges 362 pasted on the inner walls of the upper and lower cross beams 3611 of the parallel beams 361, and a bridge-forming plate 363 pasted on the outer sides of the parallel beams 361.

[0098] The parallel beam 361 is a rectangular frame structure composed of a cross beam 3611 and a vertical beam 3612. Semi-circular removal grooves 3613 with a semi-circular longitudinal section are symmetrically arranged on the left and right sides of the connection positions between the cross beam 3611 and the vertical beam 3612. The cross-sectional area of the longitudinal section of the cross beam 3611 is smaller than the cross-sectional area of the vertical beam 3612.

[0099] Specifically, during use, the sensitive strain structure 36 is located between the decoupling structure one 35 and the decoupling structure two 37 and the main structure is a parallel beam. Combined with the semi-circular removal grooves 3613, it absorbs the small bending and torsional deformations of the composite measurement branch 3, and helps to eliminate the interference of high-frequency vibrations on static strain measurement.

[0100] Furthermore, a set of strain gauges 362 are fixedly connected to the inner walls of the upper and lower cross beams 3611 of the parallel beam 361 respectively. The strain gauges 362 are located on the central axes of the inner walls of the cross beams 3611 and are distributed along the beam direction.

[0101] Specifically, during use, two sets of biaxial strain gauges 362 that are symmetric in position and equal in resistance value are pasted on the area with the largest deformation on the inner surface of the sensitive strain structure 36. The two biaxial strain gauges 362 are connected in sequence and form a full-bridge circuit with the bridge-forming plate 363 by welding.

[0102] Specifically, during use, the vibration isolation body 34, decoupling structure I 35, sensitive strain structure 36, and decoupling structure II 37 cooperate to enable the composite measurement branch 3 to fully absorb the interference of high-frequency vibration on static strain measurement and have two spherical hinge rotation characteristics. The parallel beam 361 can be equivalent to a two-force member and is in a stable and good low-frequency static measurement environment.

[0103] Furthermore, the piezoelectric acquisition and amplification device 4 consists of a constant-current power supply module, a charge amplifier, a signal conditioning circuit, and an output interface. The common-mode rejection ratio of the constant-current power supply module is greater than 120 dB, the bandwidth of the charge amplifier is greater than or equal to 100 kHz, the conversion rate is greater than 1 mV / pC, the signal conditioning circuit includes a high-pass filter module with an adjustable cut-off frequency range of 300 Hz to 30 kHz, and the signal conditioning circuit has a signal amplification function with an adjustable gain range of 100 to 1000. Each piezoelectric acquisition and amplification device 4 is only used to acquire the piezoelectric output signal of one composite measurement branch 3.

[0104] Specifically, during use, it is convenient to output reliable high-frequency piezoelectric signals. The piezoelectric acquisition and amplification device 4 corresponds to the composite measurement branch 3 one by one, which is convenient for the modular design of piezoelectric measurement of the broadband six-dimensional force sensor.

[0105] Furthermore, the strain acquisition and amplification device 5 consists of a constant-current power supply module, an instrumentation amplifier, a signal conditioning circuit, and an output interface. The common-mode rejection ratio of the constant-current power supply module is greater than 120 dB, the gain range of the instrumentation amplifier is 100 to 1000, the bandwidth is greater than or equal to 10 kHz, and the signal conditioning circuit includes a low-pass filter with an adjustable cut-off frequency range of 1 Hz to 500 Hz. The signal conditioning circuit has a temperature compensation function to correct the temperature drift in real time. Each strain acquisition and amplification device 5 is only used to acquire the strain output signal of one composite measurement branch 3.

[0106] Specifically, during use, it is convenient to output reliable low-frequency strain signals. The strain acquisition and amplification device 5 corresponds to the composite measurement branch 3 one by one, which is convenient for the modular design of strain measurement of the broadband six-dimensional force sensor.

[0107] Specifically, during use, the output voltage of the piezoelectric channel after being processed by the piezoelectric acquisition and amplification device 4 and the strain acquisition and amplification device 5 is u = [u1, u2, u3,... u6] T and the output voltage of the strain channel is U = [U1, U2, U3,... U6] T , then the input force F = [F x , F y , F z , M x , M y , M z T The relationship between the input force F and the output of the piezoelectric channel is F = C p ​·u, C p is the decoupling matrix of the piezoelectric channels; then the input force F = [F x , F y , F z , M x , M y , M z T The relationship with the strain channel output is F = C s ·U, C s is the decoupling matrix of the strain channels. The outputs of the piezoelectric channels and the strain channels are proportional to the axial force of the composite measurement branch, f = k·u, f = K·U. The axial force f = {f1, f2, f3, f4, f5, f6} T , where k is the coefficient of the piezoelectric channel and K is the coefficient of the strain channel.

[0108] Then the decoupling matrix C p = (kG) -1 , C s = (KG) -1 It can be seen from the following formula that the structural characteristics of the broadband six - dimensional force sensor are mainly determined by the parameters R2, R1 and H c , where the G matrix is the force influence coefficient matrix of the sensor.

[0109]

[0110] The present invention also proposes a broadband design method for the broadband six - dimensional force sensor.

[0111] A design method for a broadband six - dimensional force sensor, used to design the above - mentioned broadband six - dimensional force sensor, includes the following steps:

[0112] Taking the ratio of the upper limit value of the strain channel bandwidth to the lower limit value of the piezoelectric channel bandwidth being greater than 1 as the optimization goal;

[0113] Obtaining the main structural parameters of the composite measurement branch 3, the upper connection platform 1, and the lower connection platform 2;

[0114] Setting the optimization constraint conditions for the composite measurement branch 3, the upper connection platform 1, and the lower connection platform 2;

[0115] Modeling according to the main structural parameters and analyzing the model to obtain the optimization data;

[0116] Obtaining the final design parameters according to the optimization data, and manufacturing the broadband six - dimensional force sensor according to the final design parameters.

[0117] The specific implementation includes the following steps:

[0118] Step 1) Establishing the optimization goal;

[0119] ​Step 2) Selection of design variables;

[0120] Step 3) Setting of constraint conditions;

[0121] Step 4) Parametric modeling;

[0122] Step 5) Simulation analysis modeling;

[0123] Step 6) Result processing setting;

[0124] Step 7) Automatic analysis integration.

[0125] Step 1) Establishment of optimization objective:

[0126] As a preferred implementation, taking the ratio of the upper limit value s of the strain channel bandwidth s and the lower limit value s of the piezoelectric channel bandwidth p being greater than 1 as the optimization objective, that is:

[0127] As an additional implementation, in use, the ratio range of the upper limit value of the strain channel bandwidth to the lower limit value of the piezoelectric channel bandwidth is set to 1.1 - 1.2, which is convenient for realizing the connection between the upper limit of the strain channel bandwidth and the lower limit of the piezoelectric channel bandwidth.

[0128] Step 2) Selection of design variables:

[0129] Select the positioning angle of the upper connection platform the positioning angle of the lower connection platform the positioning circle radius R2 of the upper connection platform, the positioning circle radius R1 of the lower connection platform, and the distance H between the upper and lower connection platforms c the thickness of the upper / lower connection platforms, the cross-sectional area and height of the upper / lower connection seats, the cross-sectional area and height of the vibration isolation body support columns, the cross-sectional area and height of the decoupling structure one rotating shaft, the cross-sectional area and height of the parallel beams, and the cross-sectional area and height of the decoupling structure two as design variables, and use the above design variables as structural parameters;

[0130] As an additional implementation, the value range of the structural parameters is 70% - 150% of the initial value of the variable.

[0131] Step 3) Setting of constraint conditions:

[0132] Taking the isotropy, sensitivity, stiffness, and strength indexes of the sensor as constraints.

[0133] Step 4) Parametric modeling:

[0134] Use SOLIDWORKS to establish a parametric model of the initial structure of the broadband six-dimensional force sensor. With the positioning angle of the upper connection platform the positioning angle of the lower connection platform The radius R2 of the positioning circle of the upper connection platform, the radius R1 of the positioning circle of the lower connection platform, and the distance H between the upper and lower connection platforms c The thickness of the upper / lower connection platforms, the cross-sectional area and height of the upper / lower connection seats, the cross-sectional area and height of the support columns of the vibration isolation body, the cross-sectional area and height of the rotating shaft of the decoupling structure I, the cross-sectional area and height of the parallel beams, and the cross-sectional area and height of the decoupling structure II are used as design parameters. The model is saved in a parametric format, preferably as an.sldprt file, and the model is exported in a format supported by ABAQUS, preferably as a.step file. At the same time, the model automatic update setting is performed, a VBA macro is written, and it is saved as an.swp script file.

[0135] Step 5) Simulation analysis and modeling:

[0136] ABAQUS is used for finite element simulation calculation of the parametric model. The.step file exported from SOLIDWORKS is imported into ABAQUS for assembly generation, material property setting, mesh division, and boundary condition setting.

[0137] As an additional implementation method, the steps of simulation analysis and modeling include:

[0138] 1. Define static general analysis: Calculate the strain in the strain channel patch area, the maximum stress of the structure, the displacement and rotation angle at the connection position between the upper connection platform and the outside.

[0139] 2. Define linear perturbation analysis to calculate the strain channel response curve.

[0140] 3. Define a linear perturbation analysis step to calculate the piezoelectric channel response curve. The strain in the patch area, the maximum stress of the structure, the displacement and rotation angle at the connection position between the upper connection platform and the outside, the strain channel response curve, and the piezoelectric channel response curve are set as field outputs, and the analysis results are output as an.odb file.

[0141] At the same time, the parametric model automatic update and analysis task automatic operation settings are performed, and a PYTHON.py script file for ABAQUS is written.

[0142] Step 6) Result processing settings:

[0143] MATLAB is used for setting the objective function. By using MATLAB to read the.odb file output by ABAQUS, the strain in the patch area, the maximum stress of the structure, the displacement and rotation angle at the connection position between the upper connection platform and the outside, the strain channel response curve, and the piezoelectric channel response curve are extracted.

[0144] Set the ratio of the upper limit value of the strain channel bandwidth to the lower limit value of the piezoelectric channel bandwidth to be greater than 1 as the objective function Calculate the isotropy, sensitivity, stiffness, and strength values of the objective function and constraint indicators. And save them as a.m script file for automated result processing.

[0145] Step 7) Automatic analysis integration:

[0146] Use ISIGHT for optimization integration settings. Create a new optimization project in ISIGHT and set the design variables: the positioning angle of the upper connecting platform the positioning angle of the lower connecting platform the positioning circle radius R2 of the upper connecting platform, the positioning circle radius R1 of the lower connecting platform, and the distance H between the upper and lower connecting platforms c and the thickness of the upper / lower connecting platforms, the cross-sectional area and height of the upper / lower connecting seats, the cross-sectional area and height of the vibration isolation body support columns, the cross-sectional area and height of the rotation axis of the decoupling structure I, the cross-sectional area and height of the parallel beams, and the cross-sectional area and height of the decoupling structure II as design variables, and the variable space is 70% - 150% of the variable initial value.

[0147] Set the constraint conditions: Take the isotropy, sensitivity, stiffness, and strength as the constraint conditions. Set the objective function: The ratio of the upper limit value of the strain channel bandwidth to the lower limit value of the piezoelectric channel bandwidth is greater than 1 as the objective function It can be taken as 1.2.

[0148] Call the.swp script file of the SOLIDWORKS script interface, the.py script file of the ABAQUS PYTHON interface, and the.m script file of the MATLAB engine interface through the Simcode component to integrate SOLIDWORKS, ABAQUS, and MATLAB. Set the standard particle swarm optimization algorithm as the optimization analysis driver in ISIGHT, and set the initial algorithm parameters: the particle population size (80 - 120), the maximum number of iterations (100 - 200).

[0149] Specifically, when in use, ISIGHT first calls the particle swarm optimization algorithm for particle swarm initialization settings. Secondly, call SOLIDWORKS and ABAQUS to create a parametric model and perform finite element calculations, and extract the strain in the bonding area, the maximum stress of the structure, the displacement, rotation angle, strain channel response curve, and piezoelectric channel response curve at the connection position between the upper connecting platform and the outside. Finally, call MATLAB to solve the objective function, isotropy, sensitivity, and stiffness, and supply the particle swarm optimization algorithm for individual and population extreme value updates to realize particle velocity and position updates. Through continuous cycling, until the termination condition is met, the optimal Pareto solution set is obtained. The constructed integrated automated analysis system can reduce the error rate of manual operations and save the cost of optimal design.

[0150] The present invention discloses a broadband design method for a six - dimensional force sensor based on structural optimization design. By integrating SOLIDWORKS, ABAQUS, and MATLAB based on the particle swarm optimization algorithm in ISIGHT, it effectively solves the problem of connecting the frequency domains of the strain channels and the piezoelectric channels in the strain - piezoelectric hybrid measurement of the six - dimensional force sensor. The automated analysis process reduces manual operation errors and improves the optimization analysis efficiency. The parametric analysis system is easy to modify and can conveniently achieve the multi - objective engineering design of strain - piezoelectric hybrid six - dimensional force sensors with various structures.

[0151] A method for using a broadband six - dimensional force sensor includes the following steps:

[0152] 1) Cut - off frequency setting;

[0153] 2) Sensor calibration;

[0154] 3) Decoupling of calibration data;

[0155] 4) Fusion of measured values of strain - piezoelectric channels.

[0156] 1) Cut - off frequency setting:

[0157] Take the lower limit value of the piezoelectric channel bandwidth as the low - pass filter cut - off frequency of the strain acquisition and amplification device, and the upper limit value of the strain channel bandwidth as the high - pass filter cut - off frequency of the piezoelectric acquisition and amplification device.

[0158] Specifically, when in use, when the actual frequency of the external load is lower than the lower limit value of the piezoelectric channel bandwidth, only the strain channel of the broadband six - dimensional force sensor has a voltage signal output. When the actual frequency of the external load is higher than the upper limit value of the strain channel bandwidth, only the piezoelectric channel of the broadband six - dimensional force sensor has a voltage signal output. When the actual frequency of the external load is between the lower limit value of the piezoelectric channel bandwidth and the upper limit value of the strain channel bandwidth, both the strain channel and the piezoelectric channel of the broadband six - dimensional force sensor have voltage signal outputs.

[0159] 2) Sensor calibration:

[0160] Adopt the common six - dimensional force sensor calibration method, which is well - known to those of ordinary skill in the art. Briefly describe the implementation process here: For six directions (along the x, y, z axes and rotation around the x, y, z axes), complete the loading and recording. Three effective loadings and recordings need to be completed in each direction.

[0161] Specifically, the loading method in each direction is to gradually load the load from zero to the full scale at the measurement point, then reduce it to zero, then gradually increase it to the negative - direction full scale, and then reduce it to zero, completing a test cycle. Record the corresponding output data of the strain channel and the piezoelectric channel. (Three pre - loadings need to be carried out in accordance with the above method before the formal calibration in each direction).

[0162] 3) Decoupling of calibration data:

[0163] Using methods such as the least squares method and RBF neural network (well-known to those of ordinary skill in the art, the implementation process description is omitted here), decouple the output voltage signal to obtain the measurement values of the strain channels and piezoelectric channels of the broadband six-dimensional force sensor in the broadband frequency domain.

[0164] 4) Fusion of measurement values of strain and piezoelectric channels:

[0165] The fused output of the designed measurement values of strain and piezoelectric channels is

[0166] F total =W low (v)·F strain +W high (v)·F piezoelectricity

[0167] Where F total is the actual output force value of the broadband six-dimensional force sensor, F strain is the static output force of the strain channel, F piezoelectricity is the dynamic output force of the piezoelectric channel, W low (v) is the weight coefficient of the static output force of the strain channel, W high (v) is the weight coefficient of the dynamic output force of the piezoelectric channel, and v represents the actual frequency of the external load.

[0168] Specifically, during use, the change of the weight coefficient is regulated by the HanningWindow function, and W high (v) is

[0169]

[0170] W low (v)=1 - W high (v)

[0171] Where λ1 and λ2 are frequency domain segmentation control parameters, λ1 ranges from 0.8 to 0.9, and λ2 ranges from 1.1 to 1.2. v plow is the lower limit frequency value of the bandwidth of the piezoelectric channel, and v shigh is the upper limit frequency value of the bandwidth of the strain channel.

[0172] Further, during use, when a low-frequency load (with a frequency less than or equal to λ1 times the lower limit frequency value of the piezoelectric channel bandwidth) acts on the sensor, only the strain channel of the broadband six-dimensional force sensor outputs a voltage signal, and the static measurement value of the strain channel is used as the output of the broadband six-dimensional force sensor. When a high-frequency load (with a frequency greater than or equal to λ2 times the upper limit frequency value of the strain channel bandwidth) acts on the sensor, only the piezoelectric channel of the broadband six-dimensional force sensor outputs a voltage signal, and the dynamic measurement value of the piezoelectric channel is used as the output of the broadband six-dimensional force sensor. When a medium-frequency load (with a frequency greater than λ1 times the lower limit frequency value of the piezoelectric channel bandwidth and less than λ2 times the upper limit frequency value of the strain channel bandwidth) acts on the sensor, both the strain channel and the piezoelectric channel of the broadband six-dimensional force sensor output voltage signals. In cooperation with a standard piezoelectric acceleration sensor (the ideal working frequency measurement range of the piezoelectric acceleration sensor is greater than or equal to λ1 times the lower limit value of the piezoelectric channel bandwidth), the external load frequency is measured, and the static measurement value of the strain channel and the dynamic measurement value of the piezoelectric channel are calculated through the above HanningWindow function and combined in a certain proportion as the output of the broadband six-dimensional force sensor, realizing accurate measurement of force values in the low-frequency band, medium-frequency band, and high-frequency band.

[0173] The present invention discloses a method for using a broadband six-dimensional force sensor. Through multiple-step designs such as cut-off frequency setting, sensor calibration, decoupling of calibration data, and fusion of measurement values of the strain and piezoelectric channels, multi-mode use under low-frequency loads, medium-frequency loads, and high-frequency loads based on the fusion of the output of the strain channel and the output of the piezoelectric channel of the broadband six-dimensional force sensor is achieved.

[0174] Further, the upper connection platform 1, the lower connection platform 2, and the composite measurement branch 3 in the present invention can be formed by integrated wire cutting, overcoming the problems of zero-crossing and hysteresis caused by assembly, and improving the bearing capacity and measurement accuracy of the sensor. Taking the lower limit of the piezoelectric channel bandwidth as the low-pass filter cut-off frequency of the strain acquisition and amplification device of the strain channel, and the upper limit of the strain channel bandwidth as the high-pass filter cut-off frequency of the piezoelectric acquisition and amplification device, through the high-pass filtering of the piezoelectric channel and the low-pass filtering of the strain channel, multiple measurement forms such as low-frequency band force strain measurement, medium-frequency band force strain and piezoelectric hybrid measurement, and high-frequency band force piezoelectric measurement are realized, integrating the advantages of high low-frequency measurement accuracy of strain measurement and high high-frequency measurement accuracy of piezoelectric measurement, and completing high-precision measurement of broadband six-dimensional force based on the strain measurement principle and the piezoelectric measurement principle.

[0175] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0176] The above embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A broadband six-dimensional force sensor, characterized in that, Comprising: An upper connection platform (1) and a lower connection platform (2) which are coaxially arranged. The upper connection platform (1) and the lower connection platform (2) are connected by composite measurement branches (3) arranged at equal intervals circumferentially. The composite measurement branches (3) are electrically connected to a signal amplification device, and the signal amplification device is arranged between the upper connection platform (1) and the lower connection platform (2); The composite measurement branch (3) has a V-shaped structure. A piezoelectric component (33) and a sensitive strain structure (36) are arranged inside the composite measurement branch (3). The piezoelectric component (33) is arranged close to the upper connection platform (1), and the sensitive strain structure (36) is arranged close to the lower connection platform (2). The piezoelectric component (33) and the sensitive strain structure (36) are connected by a decoupling structure; The decoupling structure includes a first decoupling structure (35) and a second decoupling structure (37). The first decoupling structure (35) has two layers of I-shaped structures, and the included angle between the straight lines where the webs of the two layers of I-shaped structures are located is 90°; The second decoupling structure (37) is a wedge-shaped prism. The second decoupling structure (37) has three mutually perpendicular and co-intersecting self-rotation axes. The large end face of the second decoupling structure (37) is connected to the lower connection platform (2), and the sensitive strain structure (36) is connected and arranged between the small end face of the second decoupling structure (37) and the first decoupling structure (35).

2. The six-axis force sensor with a wide frequency domain according to claim 1, characterized in that The composite measurement branch (3) includes an upper connection seat (31). The upper connection seat (31) has a V-shaped structure. The first end of the upper connection seat (31) is fixed to the upper connection platform (1). One end of a vibration isolation body (34) is fixedly connected to both the second end and the third end of the upper connection seat (31). The other end of the vibration isolation body (34) is fixedly connected to one end of the corresponding first decoupling structure (35); The other end of the first decoupling structure (35) is fixedly connected to one end of the corresponding sensitive strain structure (36). The other end of the sensitive strain structure (36) is fixedly connected to the small end face of the second decoupling structure (37). One end of a lower connection seat (32) is fixedly connected to the large end face of the second decoupling structure (37), and the other end of the lower connection seat (32) is fixedly connected to the lower connection platform (2); The piezoelectric component (33) is embedded and fixed in the upper connection seat (31).

3. The six-axis force sensor with a wide frequency domain according to claim 2, characterized in that: The vibration isolation body (34) includes a support column body (341). One side of the support column body (341) is fixedly connected to the second end / third end of the upper connection seat (31), and the other side of the support column body (341) is fixedly connected to the first decoupling structure (35). Flexible silicone damping bodies (342) are filled between the support column body (341) and the second end / third end of the upper connection seat (31), and between the support column body (341) and the first decoupling structure (35).

4. A broadband six - dimensional force sensor according to claim 1, characterized in that: The top of the upper connection platform (1) is provided with a number of force application holes (11) arranged at equal intervals circumferentially. The top of the upper connection platform (1) is provided with two first positioning pin holes (12), and the included angle between the center line of the top of the upper connection platform (1) and the two first positioning pin holes (12) is 90°.

5. The six-dimensional force sensor with a wide frequency domain according to claim 1, characterized in that: The bottom of the lower connection platform (2) is provided with a number of mounting holes (21) arranged at equal intervals circumferentially. The bottom of the lower connection platform (2) is provided with two second positioning pin holes (22), and the included angle between the center line of the bottom of the lower connection platform (2) and the two second positioning pin holes (22) is 90°.

6. The six-axis force sensor with a wide frequency domain according to claim 2, characterized in that, The piezoelectric component (33) includes: Mounting cabins (334) are opened on the upper connection seat (31), and there are two mounting cabins (334) which are symmetrically arranged; A single-dimensional force measuring crystal group (331) composed of a number of stacked cut-type quartz wafers is installed in the mounting cabin (334); A cover (332) is sleeved outside the single-dimensional force measuring crystal group (331). The cover (332) is used to fix the single-dimensional force measuring crystal group (331) in the mounting cabin (334), and the cover (332) and the mounting cabin (334) are fixed by pre-tightening screws (333).

7. The six-axis force sensor in a wide frequency domain according to claim 1, characterized in that: The signal amplification device includes a piezoelectric acquisition and amplification device (4) and a strain acquisition and amplification device (5). The piezoelectric acquisition and amplification device (4) is fixed on the upper connection platform (1) and is electrically connected to the piezoelectric component (33), and the strain acquisition and amplification device (5) is fixed on the lower connection platform (2) and is electrically connected to the sensitive strain structure (36).

8. The six-dimensional force sensor with a wide frequency domain according to claim 1, characterized in that: The sensitive strain structure (36) includes a parallel beam (361). The parallel beam (361) is a hollow structure. Strain gauges (362) are pasted on the top wall and the bottom wall of the inner cavity of the parallel beam (361), and a bridge plate group (363) is fixedly connected to the outer wall surface of the parallel beam (361); The parallel beam (361) is composed of two cross beams (3611) and two vertical beams (3612) to form a rectangular frame structure. The strain gauges (362) are fixed on the inner walls of the cross beams (3611), the bridge plate group (363) is fixedly connected to the outer walls of the vertical beams (3612), and two semi-circular removal grooves (3613) are opened on the outer walls of the vertical beams (3612). The bridge plate group (363) is located between the two semi-circular removal grooves (3613).

9. A design method for a broadband six - dimensional force sensor, which is used to design a broadband six - dimensional force sensor according to any one of claims 1 - 8, characterized in that, It includes the following steps: Taking the ratio of the upper limit value of the strain channel bandwidth to the lower limit value of the piezoelectric channel bandwidth being greater than 1 as the optimization goal; Obtaining the main structural parameters of the composite measurement branch (3), the upper connection platform (1), and the lower connection platform (2); Setting the optimization constraint conditions for the composite measurement branch (3), the upper connection platform (1), and the lower connection platform (2); Modeling according to the main structural parameters and analyzing the model to obtain optimization data; Obtaining the final design parameters according to the optimization data, and manufacturing the broadband six-dimensional force sensor according to the final design parameters.

10. A method for using a broadband six - dimensional force sensor, which is used for using a broadband six - dimensional force sensor according to any one of claims 1 - 8, characterized in that, It includes the following steps: Take the lower limit value of the piezoelectric channel bandwidth as the low-pass filter cut-off frequency of the strain acquisition and amplification device, and take the upper limit value of the strain channel bandwidth as the high-pass filter cut-off frequency of the piezoelectric acquisition and amplification device to design the amplification device; Obtain the measured values of the strain channel and the measured values of the piezoelectric channel through conventional calibration and decoupling; Design the regulation function with the external load frequency as a parameter, and set the weight coefficients of the static output force of the strain channel and the dynamic output force of the piezoelectric channel based on the regulation function; Set the fusion output of the measured values of the strain channel and the measured values of the piezoelectric channel with the weight coefficients as the distribution ratio.

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