Novel wide-range box type piezoelectric six-component balance and calibration method thereof

Abstract

The invention discloses a novel wide-range box-type piezoelectric six-component balance and a calibration method thereof.The novel wide-range box-type piezoelectric six-component balance comprises a base, a second sensor, a fourth sensor, a sixth sensor and an eighth sensor are arranged at the four corners of the interior of the base respectively, and the second sensor, the fourth sensor, the sixth sensor and the eighth sensor are arranged in a rectangular shape; and a sensor I, a sensor III, a sensor V and a sensor VII are respectively arranged among the sensor II, the sensor IV, the sensor VI and the sensor VIII. In the measuring process, all the measuring sites participate in torque measurement and stress measurement, the defect of torque measurement of a diamond structure can be well overcome, the diamond structure layout is combined for excellent measurement of normal stress, the distances between the four measuring sites and the mechanical coordinate axis are the same, the calculated amount can be relatively reduced, and the measurement accuracy is improved. And the eight sensors are arranged, and the internal structures of the sensors are different, so that the calculation amount can be reduced, the inter-dimensional coupling can be reduced, and the error can be reduced.

Description

Technical Field

[0001] The invention relates to the field of wind power generation, and in particular to a novel large-range box-type piezoelectric six-component force balance and a calibration method thereof. Background Art

[0002] In the context of energy conservation and emission reduction, the wind power industry is developing rapidly. In order to simulate the uncertainty of wind direction and wind speed in the natural environment, large-load wind power equipment, complete machines and components need to be continuously tested in wind tunnels to detect their performance. Therefore, the demand for high-precision, high-sensitivity, high-speed and dynamic measurement six-component force balances has greatly increased.

[0003] Among the existing six-component force sensors, the measurement characteristics of the piezoelectric six-component force sensor are relatively consistent with these requirements, so the development of the six-component force box-type piezoelectric balance in the application field of wind tunnel balance has groundbreaking research significance.

[0004] The sensors of traditional force-measuring piezoelectric balances have exactly the same performance and manufacturing process, and the internal structure of the crystal group is exactly the same. The inter-dimensional coupling is large, the error is large, and a large amount of decoupling calculations are required later, which is costly and complicated. If the number of sensors in a six-component piezoelectric balance is too small, the span between sensors will become larger, resulting in a lack of rigidity in the balance system, excessive deformation of the sensors, and prominent problems of inter-dimensional interference; conversely, it will make the balance structure more complicated and increase the difficulty and cost of manufacturing.

[0005] The box-type piezoelectric six-component force balance designed by the present invention has made improvements in both the crystal structure and the layout of the sensor, and has well overcome the drawbacks of the traditional six-component force balance, so the research significance of the present invention is significant. Summary of the invention

[0006] The object of the present invention is to provide a novel large-range box-type piezoelectric six-component force balance and a calibration method thereof to solve the problems raised in the above-mentioned background technology.

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

[0008] A new large-range box-type piezoelectric six-component force balance, including

[0009] A base, wherein four inner corners of the base are respectively provided with sensor 2, sensor 4, sensor 6 and sensor 8, and the sensor 2, sensor 4, sensor 6 and sensor 8 are arranged in a rectangular shape;

[0010] Sensor 1, sensor 3, sensor 5 and sensor 7 are respectively arranged between sensor 2, sensor 4, sensor 6 and sensor 8, and sensor 1, sensor 3, sensor 5 and sensor 7 are arranged in a diamond shape;

[0011] A cover plate is arranged just above the top of the base, and the sensor 1, sensor 3, sensor 5, sensor 7, sensor 2, sensor 4, sensor 6 and sensor 8 are all fixedly connected to the cover plate and the base by countersunk screws.

[0012] In the present invention, the geometric center of the diamond structure formed by the sensor 1, the sensor 3, the sensor 5 and the sensor 7 coincides with the geometric center of the rectangular structure formed by the sensor 2, the sensor 4, the sensor 6 and the sensor 8.

[0013] In the present invention, the geometric center of the diamond structure formed by the sensor one, the sensor three, the sensor five and the sensor seven is set as the coordinate origin, and the axial diagonal of the diamond structure is set as the X-axis, and the longitudinal diagonal is set as the Y-axis. The sensor one, the sensor three, the sensor five and the sensor seven are respectively located on the X-axis and the Y-axis, and the sensor two, the sensor four, the sensor six and the sensor eight are respectively located on both sides of the X-axis and the Y-axis.

[0014] In the present invention, the sensor 1, sensor 3, sensor 5 and sensor 7 are composed of a group of X-cut crystal groups and two groups of Y-cut crystal groups stacked up and down, and one group of the X-cut crystal groups and the two groups of the Y-cut crystal groups are connected in parallel.

[0015] In the present invention, the sensor 2, sensor 4, sensor 6 and sensor 8 are composed of two groups of X-cut crystal groups and one group of Y-cut crystal groups stacked up and down, and the two groups of X-cut crystal groups and one group of Y-cut crystal groups are connected in parallel.

[0016] In the present invention, the X-cut crystal group and the Y-cut crystal group are both composed of two quartz wafers stacked up and down, an output electrode sheet is arranged between the two quartz wafers, the two quartz wafers of the X-cut crystal group are connected in series, and the two quartz wafers of the Y-cut crystal group are connected in series.

[0017] In the present invention, an isolation gasket is provided at the connection between the X-cut crystal group and the Y-cut crystal group, or at the connection between two X-cut crystal groups or two Y-cut crystal groups.

[0018] In the present invention, the quartz wafer is a square crystal ring with a thickness of 1 mm, and the four corners of the quartz wafer are cut off with a side length of 1 mm and a 45° round chamfer.

[0019] In the present invention, the four outer sides of the base are provided with wire outlet holes, and the four central corners of the upper end of the cover are provided with screw holes.

[0020] A new large-range box-type piezoelectric six-component force balance calibration method comprises the following steps:

[0021] Step S1, connecting each sensor to three charge amplifiers, and connecting each charge amplifier to a crystal group, to amplify the electrical signal of each crystal group;

[0022] Step S2, applying a known force to the box-type piezoelectric quartz balance, recording the electrical signal output values ​​of twenty-four charge amplifiers, and constructing an equation group including multiple equations;

[0023] Step S3, determining the linear relationship between the electrical signals of the twenty-four charge amplifiers and the six force components;

[0024] Step S4, solving the coefficient matrix by the least square method so as to minimize the residual sum of squares.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. In the measurement process of the present invention, the measurement sites are all involved in the measurement of torque and stress, which can well make up for the deficiency of the diamond structure in torque measurement, and combine the excellent measurement of normal stress by the diamond structure layout. In addition, the distances between the four measurement sites and the mechanical coordinate axis are the same, which can relatively reduce the amount of calculation. Moreover, by setting eight sensors, and each sensor has a different internal structure, the amount of calculation can be reduced, the inter-dimensional coupling can be reduced, and the error can be reduced.

[0027] 2. The measuring range of the balance of the present invention is about 16kN (2000N×8). By expanding the measuring range by more than ten times, the measuring range of the piezoelectric balance is greatly increased, which can adapt to a wider range of wind tunnel test conditions and models, and help to capture the dynamic changes under more complex and extreme working conditions, such as high speed and strong wind conditions, and can improve the precision and accuracy of the measurement, enhance the research capabilities of new and large aircraft structures, and provide strong support for research and development;

[0028] 3. The present invention uses the idea and framework of multivariate linear regression statistical analysis and the calculation method of least squares method to determine the relationship between electrical signals and force signals, thereby achieving accurate measurement of force and torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the overall structure of a novel large-range box-type piezoelectric six-component force balance of the present invention;

[0030] Figure 2 This is a sensor arrangement diagram of a novel large-range box-type piezoelectric six-component force balance of the present invention;

[0031] Figure 3 It is a structural schematic diagram of a sensor of a novel large-range box-type piezoelectric six-component force balance of the present invention;

[0032] Figure 4The present invention is a schematic diagram of the structure of sensor 2 of a novel large-range box-type piezoelectric six-component force balance.

[0033] In the figure: 1. Sensor 1; 2. Sensor 2; 3. Sensor 3; 4. Sensor 4; 5. Sensor 5; 6. Sensor 6; 7. Sensor 7; 8. Sensor 8; 9. Base; 10. Cover; 11. Countersunk screw; 12. X-cut crystal group; 13. Y-cut crystal group; 14. Quartz wafer; 15. Isolation gasket; 16. Wire outlet hole; 17. Screw hole. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1-Figure 4 , the present invention provides a technical solution:

[0036] A novel large-range box-type piezoelectric six-component force balance, comprising a base 9, the four outer sides of the base 9 are provided with outlet holes 16, the upper center four corners of the cover plate 10 are provided with screw holes 17, the inner four corners of the base 9 are respectively provided with sensor 2 2, sensor 4 4, sensor 6 6 and sensor 8 8, the sensor 2 2, sensor 4 4, sensor 6 6 and sensor 8 8 are arranged in a rectangular shape, and sensor 1 1, sensor 3 3, sensor 5 5 and sensor 7 7 are respectively provided between the sensor 2 2, sensor 4 4, sensor 6 6 and sensor 8 8, and the sensor 1 1, sensor 3 3, sensor 5 5 and sensor 8 8 are respectively provided between the sensor 1 The sensors 7 are arranged in a diamond shape, and a cover plate 10 is arranged just above the top of the base 9. The sensors 1, 3, 5, 7, 2, 4, 6, and 8 are all fixedly connected to the cover plate 10 and the base 9 by countersunk screws 11. The geometric center of the diamond structure formed by the sensors 1, 3, 5, and 7 coincides with the geometric center of the rectangular structure formed by the sensors 2, 4, 6, and 8. The geometric center of the diamond structure formed by the sensors 1, 3, 5, and 7 coincides with the geometric center of the rectangular structure formed by the sensors 2, 4, 6, and 8. The center is set as the coordinate origin, and the axial diagonal of the diamond structure is set as the X-axis, and the longitudinal diagonal is set as the Y-axis. Sensor 1 1, sensor 3 3, sensor 5 and sensor 7 7 are respectively located on the X-axis and the Y-axis. Sensor 2 2, sensor 4 4, sensor 6 6 and sensor 8 8 are respectively located on both sides of the X-axis and the Y-axis. Sensor 1 1, sensor 3 3, sensor 5 and sensor 7 7 are composed of a group of X-cut crystal groups 12 and two groups of Y-cut crystal groups 13 stacked up and down. One group of X-cut crystal groups 12 and two groups of Y-cut crystal groups 13 are connected in parallel. Sensor 2 2, sensor 4 4, sensor 6 6 and sensor The sensor 88 is composed of two groups of X-cut crystal groups 12 and one group of Y-cut crystal groups 13 stacked up and down, the two groups of X-cut crystal groups 12 and one group of Y-cut crystal groups 13 are connected in parallel, the X-cut crystal groups 12 and the Y-cut crystal groups 13 are each composed of two quartz wafers 14 stacked up and down, an output electrode sheet is arranged between the two quartz wafers 14, the two quartz wafers 14 of the X-cut crystal group 12 are connected in series, and the two quartz wafers 14 of the Y-cut crystal group 13 are connected in series, and an isolation gasket 15 is arranged at the connection between the X-cut crystal group 12 and the Y-cut crystal group 13, and at the connection between the two X-cut crystal groups 12 or the two Y-cut crystal groups 13.

[0037] In this embodiment, sensor 1, sensor 3, sensor 5, and sensor 7 are arranged in a diamond structure, the geometric center of the diamond is set as the coordinate origin, the axial diagonal is set as the X axis, and the longitudinal diagonal is set as the Y axis, then sensor 1, sensor 3, sensor 5, and sensor 7 are all located on the coordinate axis, and sensor 1, sensor 3, sensor 5, and sensor 7 are composed of a group of X-cut crystal groups 12 and two groups of Y-cut crystal groups 13, which can ensure the optimal measurement of stress load, but it will make only two measurement sites perform measurement work and output valid measurement data in the process of measuring the torque, while the other two measurement sites are on their coordinate axes. , it is impossible to output valid data, thereby affecting the measurement accuracy of the torque; sensor two 2, sensor four 4, sensor six 6 and sensor eight 8 are arranged on both sides of the coordinate axis in a rectangular structure, and the geometric center is set to coincide with the coordinate origin. Sensor two 2, sensor four 4, sensor six 6 and sensor eight 8 are composed of two groups of X-cut crystal groups 12 and one group of Y-cut crystal group 13. In this layout, during the measurement process, the measurement sites are all involved in the measurement of torque and stress, which can well make up for the shortcomings of the diamond structure for torque measurement, and combined with the excellent measurement of normal stress by the diamond structure layout, and the distances between the four measurement sites and the mechanical coordinate axis are the same, which can relatively reduce the amount of calculation.

[0038] It can be understood that the sensors of traditional force-measuring piezoelectric balances have exactly the same performance and manufacturing process, and the internal structure of the crystal group is exactly the same. The inter-dimensional coupling is large, the error is relatively large, and a large amount of decoupling calculations are required later, which is costly and complex. The eight sensors in the present invention have different internal structures, which can reduce the amount of calculation, reduce the inter-dimensional coupling, and reduce the error.

[0039] Specifically, the device is composed of eight three-axis force sensors, each of which is composed of an X-cut crystal group 12 and a Y-cut crystal group 13. Figure 3 and Figure 4 As shown, two quartz wafers 14 of the same cut shape form a group, with a total of three groups. Output electrode sheets are installed between each quartz wafer 14 to lead out electrical signals. Isolation gaskets 15 are installed between each group. The sensor at each measurement site has corresponding measurement outputs for tangential loads and normal loads based on the polarization direction.

[0040] like Figure 3-Figure 4As shown, in sensor 1, sensor 3, sensor 5 and sensor 7, the wafers of the crystal group have the same structure and are arranged in a diamond structure. Since they are all located on the coordinate axis, the error of torque measurement is relatively large, so sensor 1, sensor 3, sensor 5 and sensor 7 are mainly used for three-dimensional stress measurement. Sensor 1, sensor 3, sensor 5 and sensor 7 are two X-cut wafers arranged horizontally on the upper layer to form the first quartz crystal group. The electric axis direction of the quartz wafer 14 is set to be consistent with the Z direction. The longitudinal piezoelectric effect is applied. The two quartz wafers 14 are connected in series to be responsible for the Z-axis. The force component in the direction is measured; two Y-cut wafers are arranged horizontally in the middle layer to form a second quartz crystal group, and the electric axis direction is consistent with the X direction, and the shear piezoelectric effect is applied. The two quartz wafers 14 are connected in series, which is responsible for measuring the force component in the X-axis direction; two Y-cut quartz wafers 14 are arranged horizontally in the lower layer to form a third quartz crystal group, and the electric axis direction is consistent with the Y direction, and the shear piezoelectric effect is applied. The two quartz wafers 14 are connected in series, which is responsible for measuring the force component in the Y-axis direction; the three groups of sensors are connected in parallel, and the total output charge increases at this time, and the corresponding voltage sensitivity also increases accordingly.

[0041] Furthermore, sensor 2 2, sensor 4 4, sensor 6 6 and sensor 8 8 are arranged in a rectangular structure, and mainly measure three-dimensional torque. The upper and middle layers of the wafers of sensor 2 2, sensor 4 4, sensor 6 6 and sensor 8 8 crystal groups have the same composition structure. The upper layer is horizontally arranged with two X-cut quartz wafers 14, and the direction of the electric axis setting is consistent with the Z axis, which is responsible for measuring the force component in the Z axis direction; two X-cut quartz wafers are arranged in the middle, and the direction of the electric axis is consistent with the Z axis, which is responsible for measuring the force component in the Z axis direction. Among them, the bottom layer of sensor 2 2 and sensor 6 6 is arranged with Y-cut wafers, and the direction of the electric axis is consistent with the Y direction, which is responsible for measuring the force component in the Y axis direction. The bottom layer of sensor 4 4 and sensor 8 8 is horizontally arranged with two Y-cut crystal groups 13, and the direction of the electric axis is consistent with the X direction, which is responsible for measuring the force component in the X axis direction. Among them, the two electrode sheets of the upper, middle and lower layers are connected in series, and the three groups of wafer groups are connected in parallel.

[0042] It is understandable that since the charge signal output by the piezoelectric quartz sensor is extremely weak, a charge amplifier is required before the signal input. Since the manufacturing process of each quartz sensor is slightly different and affects each other, each sensor outputs three electrical signals and transmits them to the charge amplifier corresponding to each sensor to reduce the error, a total of 24 charge amplifiers.

[0043] The static equilibrium equation of the six-dimensional force sensor with the above eight-point layout is as follows:

[0044] F x = F x1 + F x3 + F x5 + F x7 + F x4 + F x8

[0045]

[0046] F z = F z1 + F z3 + F z5 + F z7 + F z2 + F z4 + F z6 + F z8 + F z2′ + F z4′ + F z6′ + F z8′

[0047] M x = (F z5 - F z1 + F z4 + F z6 - F z2 - F z8 + F z4′ + F z6′ - F z2′ - F z8′ ) × a

[0048] M y = (F z3 - F z7 + F Z2 + F Z4 - F Z6 - F Z8 + F z2′ + F z4′ - F z6′ - F z8′ ) × a

[0049] M z = (F x1 - F x5 + F x4 - F x8 + F y3 - F y7 + F y2 - F y6 ) × a

[0050] As Figure 3 and Figure 4As shown, the quartz wafer 14 is a square crystal ring with a thickness of 1 mm, and the four corners of the quartz wafer 14 are cut off with a side length of 1 mm and a 45° round chamfer.

[0051] In this embodiment, the size of the quartz crystal is usually restricted by two factors. First, the quartz crystal has size restrictions due to the cut type; second, the sensor housing has some restrictions on it, and the space for installing the crystal group is limited. Therefore, the size of the chip needs to ensure that it is easy to cut, and the assembly of the crystal group and the installation in the sensor housing must be as convenient as possible to reduce the difficulty in the sensor manufacturing process, and the size of the crystal must ensure that the load-bearing capacity, insulation impedance, and natural frequency meet the requirements of use. Based on the above conditions, the thickness of the quartz chip 14 in this device is set to 1mm, and the shape of the quartz chip 14 is set to a square crystal group ring, in which the four corners are cut off with a side length of 1mm, and the chamfer is 45°. When the square crystal group is under load, the deformation is small, the maximum equivalent stress is small, and the maximum stress distribution area is relatively small. The shear stress generated when the axial stress acts is also small, which will reduce the interference between unit crystal groups during measurement;

[0052] The optimal size of the quartz wafer 14 is obtained by the following calculation:

[0053] Calculated area of ​​a single chip:

[0054]

[0055] The formula for the limit load borne by a single sensor is expressed as:

[0056] F l =ε×F m +F p +Δ

[0057] F l =σ p ×s

[0058] in:

[0059] F l -The maximum load that a single sensor can withstand;

[0060] ε-overload factor, select 1.5;

[0061] F m -The maximum load acting on the sensor bearing surface;

[0062] F p -Sensor preload, select 1 / 10F m ;

[0063] Δ-force loss caused by chamfering of the combined crystal group. The chip chamfer is 45°, with a total of four chamfers. Δ is selected as 200N.

[0064] σ p -Quartz chip compressive strength limit, select 120N / mm 2 ;

[0065] Design the maximum measured load F m is 2000N, then F P =200N,

[0066] F l =1.5×2000+200+400=3600N

[0067] Where d = 2 mm,

[0068] Then a is obtained as 5.9mm.

[0069] Through the above calculations, it is determined that the side length a of the quartz wafer 14 in the present device is 5.9 mm, the inner circular hole diameter d is 2 mm, and the thickness h is 1 mm.

[0070] Based on the optimal size determined above, the following conclusions are drawn:

[0071] The load of the traditional box-type piezoelectric balance used in wind tunnels ranges from several hundred N to several thousand N. The balance range of the present invention is about 16kN (2000N×8). By expanding the range by more than ten times, the range of the piezoelectric balance is greatly increased, which can adapt to a wider range of wind tunnel test conditions and models, and help capture dynamic changes under more complex and extreme working conditions, such as high speed and strong wind conditions. It can improve the precision and accuracy of measurements, enhance the research capabilities of new and large aircraft structures, and provide strong support for research and development.

[0072] The charge sensitivity in the shear direction is higher than that in the normal stress direction, about twice that in the normal stress direction, because its piezoelectric constant is twice that of the normal stress. When the force measuring range in the normal stress direction is within the measuring range, the force measuring range of the shear force is definitely within the measuring range, which can ensure the safe use of the entire balance. The shear direction is mainly used for the measurement of torque, and the force variation amplitude is relatively small relative to the normal stress.

[0073] A new large-range box-type piezoelectric six-component force balance calibration method comprises the following steps:

[0074] Step S1, connecting each sensor to three charge amplifiers, and connecting each charge amplifier to a crystal group, to amplify the electrical signal of each crystal group;

[0075] Step S2, applying a known force to the box-type piezoelectric quartz balance, recording the electrical signal output values ​​of twenty-four charge amplifiers, and constructing an equation group including multiple equations;

[0076] Step S3, determining the linear relationship between the electrical signals of the twenty-four charge amplifiers and the six force components;

[0077] Step S4, solving the coefficient matrix by the least square method so as to minimize the residual sum of squares.

[0078] In this method, each sensor is connected to three charge amplifiers, and the electrical signal of the corresponding crystal group in the sensor is amplified. Substituting the corresponding electrical signal value into the linear relationship formula, the numerical value corresponding to the six components can be calculated. However, various system and process errors may be introduced during the manufacturing and use process, and considering the influence between the sensors, it is necessary to calibrate the balance system again. It is necessary to calibrate the relationship between the electrical signals of the twenty-four charge amplifiers and the six force components. The linear regression method can predict the value of the dependent variable based on the known independent variable data, thereby realizing the calibration, as follows:

[0079] A series of known forces are applied to the device, including fifteen groups of different forces in the positive X direction, which are -12000N, -10000N, -8000N, -6000N, -4000N, -2000N, 0N, 2000N, 4000N, 6000N, 8000N, 10000N, and 12000N. Each group of forces generates twenty-four electrical signals, and the electrical signal output values ​​of twenty-four charge amplifiers are recorded at the same time. Then, a set of equations containing 15×6 equations can be constructed. By solving this set of equations, the A and B matrices can be obtained to achieve the calibration of the balance.

[0080] The specific calculation formula is as follows:

[0081] There is a linear relationship between the electrical signals based on the twenty-four charge amplifiers and the six force components, which can be expressed as:

[0082]

[0083] Among them, F X 、F Y 、F Z are the three force components, M X 、M Y 、M Z There are three torque components. Q1 to Q 24 It is the electrical signal output by the twenty-four charge amplifiers, which are arranged in sequence and correspond to the electrical signals output by the charge amplifiers of the three groups of double-layer quartz crystals of the eight sensors falling from the top. ijare coefficients, a total of twenty-four, among which, b ij is the coefficient.

[0084] Then convert the above expression into a simple form: AQ+B=F, where A is the coefficient matrix to be calculated, Q is the known output value of the 24 charge amplifiers, B is the vector to be calculated, and F is the known force and torque vector. Solve it by the least squares method to minimize the residual sum of squares, that is: (AU+BF) T (AU+BF)minimum.

[0085] It is necessary to solve the above coefficients by constructing a set of equations containing 25×6 equations, and the output parameters must be repeated multiple times in the loop to fit the multiple linear regression model. Through the above method, using the ideas and framework of statistical analysis of multiple linear regression method, and utilizing the calculation means of least squares method, the relationship between electrical signals and force signals can be determined, thereby achieving accurate measurement of force and torque.

[0086] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0087] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new type of large-range box-type piezoelectric six-component force balance, characterized by: include A base (9), wherein four corners of the base (9) are respectively provided with a second sensor (2), a fourth sensor (4), a sixth sensor (6) and an eighth sensor (8), wherein the second sensor (2), the fourth sensor (4), the sixth sensor (6) and the eighth sensor (8) are arranged in a rectangular shape; A sensor 1 (1), a sensor 3 (3), a sensor 5 (5) and a sensor 7 (7) are respectively arranged between the sensor 2 (2), the sensor 4 (4), the sensor 6 (6) and the sensor 8 (8), and the sensor 1 (1), the sensor 3 (3), the sensor 5 (5) and the sensor 7 (7) are arranged in a diamond shape; A cover plate (10) is arranged just above the top of the base (9), and the sensor 1 (1), sensor 3 (3), sensor 5 (5), sensor 7 (7), sensor 2 (2), sensor 4 (4), sensor 6 (6) and sensor 8 (8) are all fixedly connected to the cover plate (10) and the base (9) by countersunk screws (11).

2. A novel large-range box-type piezoelectric six-component force balance according to claim 1, characterized in that: The geometric center of the diamond structure formed by the sensor one (1), the sensor three (3), the sensor five (5) and the sensor seven (7) coincides with the geometric center of the rectangular structure formed by the sensor two (2), the sensor four (4), the sensor six (6) and the sensor eight (8).

3. According to claim 1, a novel large-range box-type piezoelectric six-component force balance is characterized in that: The geometric center of the diamond structure formed by the sensor 1 (1), the sensor 3 (3), the sensor 5 (5) and the sensor 7 (7) is set as the coordinate origin, and the axial diagonal of the diamond structure is set as the X axis, and the longitudinal diagonal is set as the Y axis. The sensor 1 (1), the sensor 3 (3), the sensor 5 (5) and the sensor 7 (7) are respectively located on the X axis and the Y axis, and the sensor 2 (2), the sensor 4 (4), the sensor 6 (6) and the sensor 8 (8) are respectively located on both sides of the X axis and the Y axis.

4. According to claim 1, a novel large-range box-type piezoelectric six-component force balance is characterized in that: The sensor one (1), the sensor three (3), the sensor five (5) and the sensor seven (7) are composed of a group of X-cut crystal groups (12) and two groups of Y-cut crystal groups (13) stacked up and down, and the group of X-cut crystal groups (12) and the two groups of Y-cut crystal groups (13) are connected in parallel.

5. A novel large-range box-type piezoelectric six-component force balance according to claim 4, characterized in that: The sensor 2 (2), the sensor 4 (4), the sensor 6 (6) and the sensor 8 (8) are composed of two groups of X-cut crystal groups (12) and one group of Y-cut crystal groups (13) stacked up and down, and the two groups of X-cut crystal groups (12) and one group of Y-cut crystal groups (13) are connected in parallel.

6. A novel large-range box-type piezoelectric six-component force balance according to claim 4, characterized in that: The X-cut crystal group (12) and the Y-cut crystal group (13) are both composed of two quartz wafers (14) stacked up and down, with output electrode sheets arranged between the two quartz wafers (14), the two quartz wafers (14) of the X-cut crystal group (12) being connected in series, and the two quartz wafers (14) of the Y-cut crystal group (13) being connected in series.

7. A novel large-range box-type piezoelectric six-component force balance according to claim 4, characterized in that: An isolation gasket (15) is provided at the connection between the X-cut crystal group (12) and the Y-cut crystal group (13), or at the connection between two X-cut crystal groups (12) or two Y-cut crystal groups (13).

8. A novel large-range box-type piezoelectric six-component force balance according to claim 6, characterized in that: The quartz wafer (14) is a square crystal ring with a thickness of 1 mm, and the four corners of the quartz wafer (14) are all cut off with a side length of 1 mm and a 45° round chamfer.

9. A novel large-range box-type piezoelectric six-component force balance according to claim 1, characterized in that: The four outer sides of the base (9) are all provided with wire outlet holes (16), and the four central corners of the upper end of the cover plate (10) are all provided with screw holes (17).

10. A calibration method for a novel large-range box-type piezoelectric six-component force balance according to claims 1-9, characterized in that: The following steps are involved: Step S1, connecting each sensor to three charge amplifiers, and connecting each charge amplifier to a crystal group, to amplify the electrical signal of each crystal group; Step S2, applying a known force to the box-type piezoelectric quartz balance, recording the electrical signal output values ​​of twenty-four charge amplifiers, and constructing an equation group including multiple equations; Step S3, determining the linear relationship between the electrical signals of the twenty-four charge amplifiers and the six force components; Step S4, solving the coefficient matrix by the least square method so as to minimize the residual sum of squares.

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