Multi-dimensional force measuring device giving consideration to static measurement and dynamic measurement

Abstract

The invention relates to the technical field of electrical variable measurement, in particular to a multi-dimensional force measurement device giving consideration to static measurement and dynamic measurement, and solves the technical problems that a traditional six-dimensional force sensor is complex and tedious in structure, relatively heavy in overall weight, incapable of giving consideration to static measurement and dynamic measurement and relatively low in measurement precision, and the multi-dimensional force measurement device comprises a measurement assembly and a vibration isolation assembly; the measuring assembly comprises a bottom plate, a top plate and a cantilever beam; the cantilever beam is connected to the bottom plate, the cantilever beam is clamped into a limiting groove of the top plate through a supporting arm, and a uniaxial strain gauge, a first biaxial strain gauge, a second biaxial strain gauge, an X-type piezoelectric crystal, a first Y-type piezoelectric crystal and a second Y-type piezoelectric crystal are arranged on the cantilever beam; the vibration isolation assembly comprises a first horizontal supporting plate, a second horizontal supporting plate, multiple layers of isolation sleeves and supporting columns, and an interlayer between every two adjacent isolation sleeves is filled with an elastic material. The device realizes the combination of static measurement and dynamic measurement, and can capture quickly changing torque and force while keeping high precision.

Description

Technical Field

[0001] The present invention relates to the technical field of measuring electrical variables, and in particular to a multi-dimensional force measuring device taking into account both static measurement and dynamic measurement. Background Art

[0002] With the development of science and technology, the technology of six-dimensional force sensors is constantly improving and its application scope is constantly expanding. In the field of modern aerospace, the requirements for operational accuracy and safety performance are becoming increasingly stringent, especially in critical missions such as satellite deployment, space station maintenance, and launch vehicle launches. In these applications, accurate measurement and control of the applied forces and the torques they generate are essential to ensure the success of the mission. The aerospace field faces a complex working environment and extreme operating conditions, which places high demands on the design and performance of six-dimensional force measurement technology. Traditional technologies such as force sensors, strain sensors, piezoelectric sensors, and inertial measurement units are widely used in the aerospace field, but the needs of aerospace-specific environments are still challenging.

[0003] Six-axis force sensors are widely used in many scientific and technological fields due to their highly integrated structure and excellent measurement performance. Their structure usually includes highly sensitive force sensing elements and complex signal processing circuits, which can convert mechanical forces into electrical signals for further analysis and application. However, the structure of traditional six-axis force sensors at home and abroad is complex and cumbersome, and the overall weight is relatively heavy. They cannot take into account both static and dynamic measurements, and the measurement accuracy is low. Summary of the invention

[0004] In order to overcome the technical defects of traditional six-dimensional force sensors, such as complex and cumbersome structure, overall heavy weight, inability to take into account both static and dynamic measurements and low measurement accuracy, the present invention provides a multi-dimensional force measurement device that takes into account both static and dynamic measurements.

[0005] The present invention provides a multi-dimensional force measuring device that takes into account both static measurement and dynamic measurement, including a measuring component and a vibration isolation component; the measuring component includes a bottom plate, a top plate and a cantilever beam; the two ends of the cantilever beam are fixedly connected to the bottom plate through two supporting rods, a supporting arm is extended upward from the middle of the cantilever beam, a limiting groove is provided on the bottom surface of the top plate, the top end of the supporting arm is inserted into the limiting groove, a uniaxial strain gauge, a first biaxial strain gauge and a second biaxial strain gauge for static measurement are arranged on the cantilever beam on the right side of the supporting arm, the sensitive grid directions of the uniaxial strain gauge, the first biaxial strain gauge and the second biaxial strain gauge are perpendicular to each other and are respectively used to detect forces and moments in corresponding directions; an X-type piezoelectric crystal, a first Y-type piezoelectric crystal and a second Y-type piezoelectric crystal for dynamic measurement are arranged on the cantilever beam on the left side of the supporting arm, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second The polarization directions of the Y-type piezoelectric crystals are perpendicular to each other and are used to detect forces and moments in corresponding directions respectively; a signal processing circuit board is arranged on the bottom plate, and a uniaxial strain gauge, a first biaxial strain gauge, a second biaxial strain gauge, an X-type piezoelectric crystal, a first Y-type piezoelectric crystal and a second Y-type piezoelectric crystal are respectively connected to the signal processing circuit board; the vibration isolation component includes a first horizontal support plate, a second horizontal support plate, a multi-layer isolation sleeve and at least one support column, the support column is fixedly connected between the first horizontal support plate and the second horizontal support plate, the support column is located at the center of the multi-layer isolation sleeve, the axes of the multi-layer isolation sleeves are collinear, and elastic materials are filled in the interlayers of adjacent isolation sleeves, and the top and bottom of the isolation sleeves are respectively abutted against the bottom surface of the first horizontal support plate and the top surface of the second horizontal support plate; the bottom plate of the measuring component is fixedly connected to the first horizontal support plate.

[0006] In the device, the upper part is the measuring component, and the lower part is the vibration isolation component. The measuring component is fixed to the top of the vibration isolation component to ensure that the force transmission is not affected. The second horizontal support plate of the vibration isolation component is fixed to the base or installation platform of the equipment, which effectively reduces the impact of environmental vibration on the measuring component and improves the measurement accuracy and stability of the measuring component. In the measuring component, the uniaxial strain gauge, the first biaxial strain gauge and the second biaxial strain gauge are responsible for static measurement, and the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal are responsible for dynamic measurement. The uniaxial strain gauge, the first biaxial strain gauge, the second biaxial strain gauge, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal have their own sensitive measurement directions, and only respond to the force in their most sensitive direction. Moreover, the uniaxial strain gauge, the first biaxial strain gauge, the second biaxial strain gauge, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal do not affect each other.

[0007] When force acts on the top plate of the measuring device, the cantilever beam is bent and deformed by the force. The uniaxial strain gauge, the first biaxial strain gauge, and the second biaxial strain gauge can detect the strain in the corresponding direction, and their resistance values ​​change. By measuring the change in the corresponding resistance value, the magnitude of the strain can be determined, and then it can be used to measure the force and torque in three mutually perpendicular directions. Similarly, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal, and the second Y-type piezoelectric crystal can detect the strain in the corresponding direction. Based on the piezoelectric effect, electric charges will be generated, and the change in charge is converted into a voltage signal, which is then used to calculate the force and torque in three mutually perpendicular directions. The uniaxial strain gauge, the first biaxial strain gauge, the second biaxial strain gauge, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal, and the second Y-type piezoelectric crystal can be processed and output separately through the signal processing circuit board, thereby obtaining independent output signals. The signal processing circuit board is a highly integrated PCB board. Its main function is to collect the resistance or voltage changes of the uniaxial strain gauge, the first biaxial strain gauge, the second biaxial strain gauge, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal, thereby generating changes in electrical signals, and then decoupling the digital signals for external transmission.

[0008] The response of the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal is relatively fast, usually at the microsecond level; the response time of the uniaxial strain gauge, the first biaxial strain gauge and the second biaxial strain gauge is relatively slow, usually at the millisecond level. The X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal can be used to capture rapidly changing dynamic forces; the uniaxial strain gauge, the first biaxial strain gauge and the second biaxial strain gauge can be used to monitor continuous static forces. Therefore, the device of the present invention can achieve full-band force measurement from static low frequency to dynamic high frequency. The uniaxial strain gauge, the first biaxial strain gauge and the second biaxial strain gauge compensate for the deficiencies of the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal in static and low-frequency measurements, while the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal compensate for the deficiencies of the uniaxial strain gauge, the first biaxial strain gauge and the second biaxial strain gauge in high-frequency and dynamic measurements.

[0009] The measuring device described in the present invention combines the stability of strain-type force measurement and the rapid response capability of piezoelectric force measurement, realizes the combination of static measurement and dynamic measurement, and can capture rapidly changing torque and force while maintaining high precision; the structure is safe and reliable, the size of each component can be reasonably adjusted, and the replacement is convenient; the vibration isolation component effectively reduces the influence of external vibration on the measurement accuracy of the measuring device, and further ensures the reliability of the measurement results; and finally realizes the precise measurement and output of six-dimensional force in an aerospace environment.

[0010] Preferably, the direction of the cantilever beam is parallel to the plane of the bottom plate, the sensitive grid direction of the uniaxial strain gauge is parallel to the Z direction, the uniaxial strain gauge is arranged on the top surface of the cantilever beam and is used to measure the force and moment in the Z direction, the sensitive grid direction of the first biaxial strain gauge is parallel to the X direction, the first biaxial strain gauge is arranged on the front side wall of the cantilever beam and is used to measure the force and moment in the X direction, the sensitive grid direction of the second biaxial strain gauge is parallel to the Y direction, the second biaxial strain gauge is arranged on the rear side wall of the cantilever beam and is used to measure the force and moment in the Y direction. Torque; the polarization direction of the X-type piezoelectric crystal is parallel to the Z direction, the X-type piezoelectric crystal is arranged on the top surface of the cantilever beam and is used to measure the force and torque in the Z direction, the polarization direction of the first Y-type piezoelectric crystal is parallel to the X direction, the first Y-type piezoelectric crystal is arranged on the front side wall of the cantilever beam and is used to measure the force and torque in the X direction, the polarization direction of the second Y-type piezoelectric crystal is parallel to the Y direction, the second Y-type piezoelectric crystal is arranged on the rear side wall of the cantilever beam and is used to measure the force and torque in the Y direction, and the X direction, Y direction and Z direction are perpendicular to each other. This arrangement is reasonable, and the specific arrangement of the uniaxial strain gauge, the first biaxial strain gauge, the second biaxial strain gauge, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal can be adjusted appropriately as needed. Taking the uniaxial strain gauge as an example, the mechanical stress applied in the Z direction will cause the resistance value of the uniaxial strain gauge to change. By measuring the corresponding change in resistance value, the magnitude of the strain can be determined, and then used to measure the force and torque in the Z direction. The measurement principle of the first biaxial strain gauge and the second biaxial strain gauge is the same as that of the uniaxial strain gauge. Taking the first Y-type piezoelectric crystal as an example, the mechanical stress applied in the X direction will cause the first Y-type piezoelectric crystal to generate an electric charge. By measuring the change in the corresponding charge, the force and torque in the X direction can be determined. Among them, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal can be polarized in the corresponding direction by applying an electric field, and the direction of the electric field will determine the polarization direction. The piezoelectric crystal is placed between the electrodes to ensure that the arrangement of the electrodes can generate an electric field parallel to the corresponding direction. The electrodes need to be placed along this direction and in close contact with the crystal surface. Appropriate voltage is applied to the electrodes through a power supply to generate a sufficiently strong electric field inside the piezoelectric crystal to induce polarization. The detection principle of the X-type piezoelectric crystal and the second Y-type piezoelectric crystal is the same as that of the first Y-type piezoelectric crystal.

[0011] Preferably, the signal processing circuit board includes an amplifier, a low-pass filter, a charge amplifier, a high-pass filter, an analog-to-digital conversion module and an output interface. The amplifier and the low-pass filter are connected in series to form a strain gauge signal conditioning subcircuit. The charge amplifier and the high-pass filter are connected in series to form a piezoelectric sheet signal conditioning subcircuit. The output end of the strain gauge signal conditioning subcircuit and the output end of the piezoelectric sheet signal conditioning subcircuit are connected in parallel to the input end of the analog-to-digital conversion module. The output signal of the analog-to-digital conversion module is processed by the data acquisition system and connected to the output interface. The output ends of the uniaxial strain gauge, the first biaxial strain gauge and the second biaxial strain gauge are respectively connected to the input end of the strain gauge signal conditioning subcircuit through corresponding Wheatstone bridges. The output ends of the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal are respectively connected to the input end of the piezoelectric sheet signal conditioning subcircuit. The output ends of the uniaxial strain gauge, the first biaxial strain gauge and the second biaxial strain gauge correspond to three Wheatstone bridges respectively, and the Wheatstone bridge can convert the resistance change of the strain gauge into a voltage change. Usually, the Wheatstone bridge consists of four resistors: R1, R2, R3 and R4. The strain gauge replaces R1 and R2 and is connected to one diagonal of the Wheatstone bridge. The other two R3 and R4 are connected to the other diagonal of the Wheatstone bridge. When the strain gauge is subjected to an external force and causes the resistance to change, the Wheatstone bridge loses balance, resulting in a non-zero output voltage. The output voltage is proportional to the resistance change of the strain gauge, so it can be used to measure force and torque. Since the piezoelectric crystal directly generates a charge signal, the charge signal is very weak and susceptible to noise interference. Therefore, a charge amplifier is required for amplification. The amplifier in the strain gauge signal conditioning subcircuit is used to amplify the signal, enhance the amplitude of the signal, and make the signal easy to be processed by the subsequent circuit. The low-pass filter is used to remove high-frequency noise and interference in the signal; the high-pass filter is used to remove low-frequency noise, such as static signal interference from the strain gauge, and retain high-frequency dynamic signals. The digital signal is processed by the data acquisition system to obtain more accurate force and torque information. The output interface can use RS485 interface to transmit the processed digital signal to external equipment or system.

[0012] Preferably, the measuring assembly further comprises a protective sleeve, which is sleeved on the outer sides of the bottom plate and the top plate, and has an interference fit with the bottom plate and the top plate. The protective sleeve can prevent debris from falling onto the cantilever beam, thereby avoiding interference with the measurement of the uniaxial strain gauge, the first biaxial strain gauge, the second biaxial strain gauge, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal, and the second Y-type piezoelectric crystal.

[0013] Preferably, the top plate, the bottom plate, the first horizontal support plate, and the second horizontal support plate are all circular plate structures, and the axes of the top plate, the bottom plate, the first horizontal support plate, the second horizontal support plate, the protective sleeve, the isolation sleeve, and the support arm are collinear; and the detection contact area of ​​the force to be measured is marked on the upper surface of the top plate. This arrangement is structurally reasonable, and the detection contact area is usually located in the center area of ​​the top plate.

[0014] Compared with the prior art, the technical solution provided by the present invention has the following technical effects: the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal in the measuring device of the present invention can be used to capture rapidly changing dynamic forces; the uniaxial strain gauge, the first biaxial strain gauge and the second biaxial strain gauge can be used to monitor continuous static forces, so the device of the present invention can achieve full-band force measurement from static low frequency to dynamic high frequency; the combination of static measurement and dynamic measurement is realized, and while maintaining high precision, rapidly changing torque and force can be captured; and the uniaxial strain gauge, the first biaxial strain gauge, the second biaxial strain gauge, the X-type piezoelectric crystal, the first Y-type piezoelectric crystal and the second Y-type piezoelectric crystal are arranged on the same cantilever beam, which minimizes the weight of the overall device, makes the structure simple, safe and reliable, and the size of each component can be reasonably adjusted, and is easy to replace; the vibration isolation component effectively reduces the influence of external vibration on the measurement accuracy of the measuring device, and further ensures the reliability of the measurement results; and finally, the precise measurement and output of six-dimensional force are achieved in an aerospace environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of the external structure of a multi-dimensional force measurement device that takes both static measurement and dynamic measurement into consideration in an embodiment of the present invention; Figure 2 It is an exploded schematic diagram of a multi-dimensional force measurement device that takes into account both static measurement and dynamic measurement according to an embodiment of the present invention; Figure 3 A cross-sectional view of a multi-dimensional force measurement device for taking both static measurement and dynamic measurement into consideration according to an embodiment of the present invention; Figure 4 It is a structural schematic diagram of the cantilever beam described in a certain embodiment of the present invention; Figure 5 Schematic diagram of the structure of the measuring component in an embodiment of the present invention.

[0018] In the figure: 1. bottom plate; 2. top plate; 3. cantilever beam; 4. support rod; 5. support arm; 6. limit groove; 7. uniaxial strain gauge; 8. first biaxial strain gauge; 9. second biaxial strain gauge; 10. X-type piezoelectric crystal; 11. first Y-type piezoelectric crystal; 12. second Y-type piezoelectric crystal; 13. signal processing circuit board; 14. first horizontal support plate; 15. second horizontal support plate; 16. isolation sleeve; 17. support column; 18. elastic material; 19. protective sleeve; 20. positioning hole. DETAILED DESCRIPTION

[0019] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0020] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0021] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0022] The following is combined with Figures 1 to 5 The specific embodiments of the present invention are described in detail.

[0023] In one embodiment, a multi-dimensional force measurement device that takes into account both static measurement and dynamic measurement includes a measurement component and a vibration isolation component; the measurement component includes a base plate 1, a top plate 2 and a cantilever beam 3; the two ends of the cantilever beam 3 are fixedly connected to the base plate 1 through two support rods 4, a support arm 5 extends upward from the middle of the cantilever beam 3, a limit groove 6 is opened on the bottom surface of the top plate 2, and the top end of the support arm 5 is inserted into the limit groove 6, and a uniaxial strain gauge 7, a first biaxial strain gauge 8 and a second biaxial strain gauge 9 for static measurement are arranged on the cantilever beam 3 on the right side of the support arm 5, and the sensitive grid directions of the uniaxial strain gauge 7, the first biaxial strain gauge 8 and the second biaxial strain gauge 9 are perpendicular to each other and are respectively used to detect forces and moments in corresponding directions; an X-type piezoelectric crystal 10, a first Y-type piezoelectric crystal 11 and a second Y-type piezoelectric crystal 12 for dynamic measurement are arranged on the cantilever beam 3 on the left side of the support arm 5, and the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 The polarization directions are perpendicular to each other and are used to detect the forces and moments in the corresponding directions respectively; a signal processing circuit board 13 is arranged on the bottom plate 1, and the uniaxial strain gauge 7, the first biaxial strain gauge 8, the second biaxial strain gauge 9, the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 are respectively connected to the signal processing circuit board 13; the vibration isolation component comprises a first horizontal support plate 14, a second horizontal support plate 15, a multi-layer isolation sleeve 16 and at least one support column 17, the support column 17 is fixedly connected between the first horizontal support plate 14 and the second horizontal support plate 15, the support column 17 is located at the center of the multi-layer isolation sleeve 16, the axes of the multi-layer isolation sleeve 16 are collinear, the interlayers of adjacent isolation sleeves 16 are filled with elastic materials 18, and the top and bottom of the isolation sleeve 16 are respectively abutted against the bottom surface of the first horizontal support plate 14 and the top surface of the second horizontal support plate 15; the bottom plate 1 of the measuring component is fixedly connected to the first horizontal support plate 14.

[0024] In the device, the upper part is a measuring component, and the lower part is a vibration isolation component. The measuring component is fixed to the top of the vibration isolation component to ensure that the force transmission is not affected. The second horizontal support plate 15 of the vibration isolation component is fixedly installed on the base or installation platform of the device, effectively reducing the impact of environmental vibration on the measuring component and improving the measurement accuracy and stability of the measuring component. In the measuring component, the uniaxial strain gauge 7, the first biaxial strain gauge 8 and the second biaxial strain gauge 9 are responsible for static measurement, and the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 are responsible for dynamic measurement. The uniaxial strain gauge 7, the first biaxial strain gauge 8, the second biaxial strain gauge 9, the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 have their own sensitive measurement directions, and only respond to the force in the most sensitive direction. Moreover, the uniaxial strain gauge 7, the first biaxial strain gauge 8, the second biaxial strain gauge 9, the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 do not affect each other.

[0025] When force acts on the top plate 2 of the measuring device, the cantilever beam 3 is bent and deformed by the force, and the uniaxial strain gauge 7, the first biaxial strain gauge 8, and the second biaxial strain gauge 9 can detect the strain in the corresponding direction, and their resistance values ​​change. By measuring the change in the corresponding resistance value, the magnitude of the strain can be determined, and then it is used to measure the force and torque in three mutually perpendicular directions. Similarly, the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11, and the second Y-type piezoelectric crystal 12 can detect the strain in the corresponding direction, and charges will be generated based on the piezoelectric effect. The change in charge is converted into a voltage signal, which is then used to calculate the force and torque in three mutually perpendicular directions. The uniaxial strain gauge 7, the first biaxial strain gauge 8, the second biaxial strain gauge 9, the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11, and the second Y-type piezoelectric crystal 12 can be processed and output separately through the signal processing circuit board 13, so that independent output signals are obtained. The signal processing circuit board 13 is a highly integrated PCB board, and its main function is to collect the resistance or voltage changes of the uniaxial strain gauge 7, the first biaxial strain gauge 8, the second biaxial strain gauge 9, the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12, thereby generating changes in electrical signals, and then decoupling the digital signals for external transmission.

[0026] The response of the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 is relatively fast, usually in the microsecond level; the response time of the uniaxial strain gauge 7, the first biaxial strain gauge 8 and the second biaxial strain gauge 9 is relatively slow, usually in the millisecond level. The X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 can be used to capture rapidly changing dynamic forces; the uniaxial strain gauge 7, the first biaxial strain gauge 8 and the second biaxial strain gauge 9 can be used to monitor continuous static forces. Therefore, the device described in the present invention can achieve full-band force measurement from static low frequency to dynamic high frequency. The uniaxial strain gauge 7, the first biaxial strain gauge 8 and the second biaxial strain gauge 9 compensate for the deficiencies of the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 in static and low-frequency measurements, while the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 compensate for the deficiencies of the uniaxial strain gauge 7, the first biaxial strain gauge 8 and the second biaxial strain gauge 9 in high frequency and dynamic measurements.

[0027] Specifically, the bottom plate 1 of the measuring assembly is directly fixedly connected to the first horizontal support plate 14 of the vibration isolation assembly by multiple bolts. The number of support columns 17 is four, and they are located in the middle of the multi-layer isolation sleeve 16. The isolation sleeve 16 is provided with three layers, and two layers of elastic material 18 are provided between the three layers of isolation sleeves 16. The elastic material 18 can be selected from silicone rubber or fluororubber. The elastic material 18 has a certain viscosity, which can make the isolation sleeve 16 and the first horizontal support plate 14 and the second horizontal support plate 15 more firmly connected. The material of the cantilever beam 3 and the support arm 5 can be selected from stainless steel.

[0028] The measuring device described in the present invention combines the stability of strain-type force measurement and the rapid response capability of piezoelectric force measurement, realizes the combination of static measurement and dynamic measurement, and can capture rapidly changing torque and force while maintaining high precision; the structure is safe and reliable, the size of each component can be reasonably adjusted, and the replacement is convenient; the vibration isolation component effectively reduces the influence of external vibration on the measurement accuracy of the measuring device, and further ensures the reliability of the measurement results; and finally realizes the precise measurement and output of six-dimensional force in an aerospace environment.

[0029] On the basis of the above embodiments, in a preferred embodiment, the direction of the cantilever beam 3 is parallel to the plane of the bottom plate 1, the sensitive grid direction of the uniaxial strain gauge 7 is parallel to the Z direction, the uniaxial strain gauge 7 is arranged on the top surface of the cantilever beam 3 and is used to measure the force and moment in the Z direction, the sensitive grid direction of the first biaxial strain gauge 8 is parallel to the X direction, the first biaxial strain gauge 8 is arranged on the front side wall of the cantilever beam 3 and is used to measure the force and moment in the X direction, the sensitive grid direction of the second biaxial strain gauge 9 is parallel to the Y direction, the second biaxial strain gauge 9 is arranged on the rear side wall of the cantilever beam 3 and is used to measure the force and moment in the X direction. Measure the force and moment in the Y direction; the polarization direction of the X-type piezoelectric crystal 10 is parallel to the Z direction, the X-type piezoelectric crystal 10 is arranged on the top surface of the cantilever beam 3 and is used to measure the force and moment in the Z direction, the polarization direction of the first Y-type piezoelectric crystal 11 is parallel to the X direction, the first Y-type piezoelectric crystal 11 is arranged on the front side wall of the cantilever beam 3 and is used to measure the force and moment in the X direction, the polarization direction of the second Y-type piezoelectric crystal 12 is parallel to the Y direction, the second Y-type piezoelectric crystal 12 is arranged on the rear side wall of the cantilever beam 3 and is used to measure the force and moment in the Y direction, and the X direction, Y direction and Z direction are perpendicular to each other. Such a structure is reasonable, and the specific arrangement of the uniaxial strain gauge 7, the first biaxial strain gauge 8, the second biaxial strain gauge 9, the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 can be appropriately adjusted as needed. Taking the uniaxial strain gauge 7 as an example, the mechanical stress applied in the Z direction will cause the resistance of the uniaxial strain gauge 7 to change. By measuring the change in the corresponding resistance, the magnitude of the strain can be determined, and then used to measure the force and torque in the Z direction. The measurement principle of the first biaxial strain gauge 8 and the second biaxial strain gauge 9 is the same as that of the uniaxial strain gauge 7. Taking the first Y-type piezoelectric crystal 11 as an example, the mechanical stress applied in the X direction will cause the first Y-type piezoelectric crystal 11 to generate a charge. By measuring the change in the corresponding charge, the force and torque in the X direction can be determined. Among them, the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 can be polarized in the corresponding direction by applying an electric field, and the direction of the electric field will determine the polarization direction. The piezoelectric crystal is placed between the electrodes to ensure that the arrangement of the electrodes can generate an electric field parallel to the corresponding direction. The electrodes need to be placed along this direction and in close contact with the crystal surface. An appropriate voltage is applied to the electrodes through a power supply to generate a sufficiently strong electric field inside the piezoelectric crystal to induce polarization. The detection principle of the X-type piezoelectric crystal 10 and the second Y-type piezoelectric crystal 12 is the same as the detection principle of the first Y-type piezoelectric crystal 11 .

[0030] On the basis of the above embodiments, in a preferred embodiment, the signal processing circuit board 13 includes an amplifier, a low-pass filter, a charge amplifier, a high-pass filter, an analog-to-digital conversion module and an output interface. The amplifier and the low-pass filter are connected in series to form a strain gauge signal conditioning subcircuit. The charge amplifier and the high-pass filter are connected in series to form a piezoelectric sheet signal conditioning subcircuit. The output end of the strain gauge signal conditioning subcircuit and the output end of the piezoelectric sheet signal conditioning subcircuit are connected in parallel to the input end of the analog-to-digital conversion module. The output signal of the analog-to-digital conversion module is connected to the output interface after being processed by the data acquisition system. The output ends of the uniaxial strain gauge 7, the first biaxial strain gauge 8 and the second biaxial strain gauge 9 are respectively connected to the input end of the strain gauge signal conditioning subcircuit through corresponding Wheatstone bridges. The output ends of the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11 and the second Y-type piezoelectric crystal 12 are respectively connected to the input end of the piezoelectric sheet signal conditioning subcircuit. The output ends of the uniaxial strain gauge 7, the first biaxial strain gauge 8 and the second biaxial strain gauge 9 correspond to three Wheatstone bridges respectively, and the Wheatstone bridge can convert the resistance change of the strain gauge into a voltage change. Usually the Wheatstone bridge consists of four resistors: R1, R2, R3 and R4. The strain gauge replaces R1 and R2 and is connected to one diagonal of the Wheatstone bridge. The other two R3 and R4 are connected to the other diagonal of the Wheatstone bridge. When the strain gauge is subjected to external force and the resistance changes, the Wheatstone bridge loses balance, thereby generating a non-zero output voltage. The output voltage is proportional to the resistance change of the strain gauge, so it can be used to measure force and torque. Since the piezoelectric crystal directly generates a charge signal, the charge signal is very weak and susceptible to noise interference. Therefore, a charge amplifier is required for amplification. The amplifier is used to amplify the signal and enhance the amplitude of the signal so that the signal can be easily processed by the subsequent circuit. The low-pass filter is used to remove high-frequency noise and interference in the signal; the high-pass filter is used to remove low-frequency noise, such as static signal interference from the strain gauge, and retain high-frequency dynamic signals. The digital signal is processed by the data acquisition system to obtain more accurate force and torque information. The output interface can use the RS485 interface, and the processed digital signal is transmitted to the external device or system through the output interface.

[0031] On the basis of the above embodiments, in a preferred embodiment, the measuring assembly further includes a protective sleeve 19, which is mounted on the outer sides of the bottom plate 1 and the top plate 2, and the protective sleeve 19 is interference fit with the bottom plate 1 and the top plate 2. The protective sleeve 19 can prevent debris from falling onto the cantilever beam 3, thereby avoiding interference with the measurement of the uniaxial strain gauge 7, the first biaxial strain gauge 8, the second biaxial strain gauge 9, the X-type piezoelectric crystal 10, the first Y-type piezoelectric crystal 11, and the second Y-type piezoelectric crystal 12. In a specific embodiment, the outer wall of the protective sleeve 19 is flush with the outer circumferential surface of the first horizontal support plate 14, the outermost isolation sleeve 16, and the second horizontal support plate 15, so that the structure is reasonable and the stability of the overall structure is better.

[0032] On the basis of the above embodiments, in a preferred embodiment, the top plate 2, the bottom plate 1, the first horizontal support plate 14 and the second horizontal support plate 15 are all circular plate structures, and the axes of the top plate 2, the bottom plate 1, the first horizontal support plate 14, the second horizontal support plate 15, the protective sleeve 19, the isolation sleeve 16 and the support arm 5 are collinear; the upper surface of the top plate 2 is marked with a detection contact area to be measured. Such a structure is reasonably set. The detection contact area is usually located in the central area of ​​the top plate 2, and the detection contact area can be set as a scale line, a marking coil, or positioned and marked through a circle of positioning holes 20.

[0033] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A multi-dimensional force measurement device that takes into account both static measurement and dynamic measurement, characterized in that: Includes measurement components and vibration isolation components; The measuring assembly comprises a bottom plate (1), a top plate (2) and a cantilever beam (3); the two ends of the cantilever beam (3) are fixedly connected to the bottom plate (1) via two support rods (4); a support arm (5) extends upward from the middle of the cantilever beam (3); a limit groove (6) is provided on the bottom surface of the top plate (2); the top end of the support arm (5) is inserted into the limit groove (6); a uniaxial strain gauge (7), a first biaxial strain gauge (8) and a second biaxial strain gauge (9) for static measurement are arranged on the cantilever beam (3) on the right side of the support arm (5); the uniaxial strain gauge (7) is provided on the bottom surface of the top plate (2); and the first biaxial strain gauge (8) and the second biaxial strain gauge (9) are provided on the cantilever beam (3) on the right side of the support arm (5). 7), the sensitive grid directions of the first biaxial strain gauge (8) and the second biaxial strain gauge (9) are perpendicular to each other and are respectively used to detect forces and moments in corresponding directions; an X-type piezoelectric crystal (10), a first Y-type piezoelectric crystal (11) and a second Y-type piezoelectric crystal (12) for dynamic measurement are arranged on the cantilever beam (3) on the left side of the support arm (5); the polarization directions of the X-type piezoelectric crystal (10), the first Y-type piezoelectric crystal (11) and the second Y-type piezoelectric crystal (12) are perpendicular to each other and are respectively used to detect forces and moments in corresponding directions; A signal processing circuit board (13) is arranged on the bottom plate (1); the uniaxial strain gauge (7), the first biaxial strain gauge (8), the second biaxial strain gauge (9), the X-type piezoelectric crystal (10), the first Y-type piezoelectric crystal (11) and the second Y-type piezoelectric crystal (12) are respectively connected to the signal processing circuit board (13); The vibration isolation component comprises a first horizontal support plate (14), a second horizontal support plate (15), a multi-layer isolation sleeve (16) and at least one support column (17), wherein the support column (17) is fixedly connected between the first horizontal support plate (14) and the second horizontal support plate (15), the support column (17) is located at the center of the multi-layer isolation sleeve (16), the axes of the multi-layer isolation sleeve (16) are collinear, the interlayers of adjacent isolation sleeves (16) are filled with elastic material (18), and the top and bottom of the isolation sleeve (16) are respectively abutted against the bottom surface of the first horizontal support plate (14) and the top surface of the second horizontal support plate (15); The bottom plate (1) of the measuring assembly is fixedly connected to the first horizontal supporting plate (14).

2. A multi-dimensional force measurement device that takes into account both static measurement and dynamic measurement according to claim 1, characterized in that: The direction of the cantilever beam (3) is parallel to the plane of the bottom plate (1), the sensitive grid direction of the uniaxial strain gauge (7) is parallel to the Z direction, the uniaxial strain gauge (7) is arranged on the top surface of the cantilever beam (3) and is used to measure the force and moment in the Z direction, the sensitive grid direction of the first biaxial strain gauge (8) is parallel to the X direction, the first biaxial strain gauge (8) is arranged on the front side wall of the cantilever beam (3) and is used to measure the force and moment in the X direction, the sensitive grid direction of the second biaxial strain gauge (9) is parallel to the Y direction, the second biaxial strain gauge (9) is arranged on the rear side wall of the cantilever beam (3) and is used to measure the force and moment in the Y direction The polarization direction of the X-type piezoelectric crystal (10) is parallel to the Z direction, the X-type piezoelectric crystal (10) is arranged on the top surface of the cantilever beam (3) and is used to measure the force and torque in the Z direction; the polarization direction of the first Y-type piezoelectric crystal (11) is parallel to the X direction, the first Y-type piezoelectric crystal (11) is arranged on the front side wall of the cantilever beam (3) and is used to measure the force and torque in the X direction; the polarization direction of the second Y-type piezoelectric crystal (12) is parallel to the Y direction, the second Y-type piezoelectric crystal (12) is arranged on the rear side wall of the cantilever beam (3) and is used to measure the force and torque in the Y direction; the X direction, the Y direction and the Z direction are perpendicular to each other.

3. The multi-dimensional force measurement device for both static and dynamic measurement according to claim 2, characterized in that: The signal processing circuit board (13) comprises an amplifier, a low-pass filter, a charge amplifier, a high-pass filter, an analog-to-digital conversion module and an output interface. The amplifier and the low-pass filter are connected in series to form a strain gauge signal conditioning subcircuit. The charge amplifier and the high-pass filter are connected in series to form a piezoelectric sheet signal conditioning subcircuit. The output end of the strain gauge signal conditioning subcircuit and the output end of the piezoelectric sheet signal conditioning subcircuit are connected in parallel to the input end of the analog-to-digital conversion module. The output signal of the analog-to-digital conversion module is processed by a data acquisition system and then connected to the output interface. The output ends of the uniaxial strain gauge (7), the first biaxial strain gauge (8) and the second biaxial strain gauge (9) are respectively connected to the input end of the strain gauge signal conditioning subcircuit through corresponding Wheatstone bridges. The output ends of the X-type piezoelectric crystal (10), the first Y-type piezoelectric crystal (11) and the second Y-type piezoelectric crystal (12) are respectively connected to the input end of the piezoelectric sheet signal conditioning subcircuit.

4. A multi-dimensional force measurement device that takes into account both static measurement and dynamic measurement according to any one of claims 1 to 3, characterized in that: The measuring assembly further comprises a protective sleeve (19), which is sleeved onto the outer sides of the bottom plate (1) and the top plate (2), and the protective sleeve (19) is interference fit with the bottom plate (1) and the top plate (2).

5. The multi-dimensional force measurement device for both static and dynamic measurement according to claim 4, characterized in that: The top plate (2), the bottom plate (1), the first horizontal support plate (14) and the second horizontal support plate (15) are all circular plate-shaped structures; the axes of the top plate (2), the bottom plate (1), the first horizontal support plate (14), the second horizontal support plate (15), the protective sleeve (19), the isolation sleeve (16) and the support arm (5) are collinear; and a detection contact area for the force to be measured is marked on the upper surface of the top plate (2).

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