A multi-dimensional force measurement device that takes into account both static and dynamic measurements

Abstract

The present invention relates to the technical field of measuring electrical variables, and in particular to a multi-dimensional force measurement device that takes into account both static and dynamic measurements. This device solves the technical problems of traditional six-dimensional force sensors, such as complex and cumbersome structures, overall weight, inability to take into account both static and dynamic measurements, and low measurement accuracy. The device comprises a measurement component and a vibration isolation component; the measurement component comprises a base plate, a top plate, and a cantilever beam; the cantilever beam is connected to the base plate, and the cantilever beam is inserted into a limit groove of the top plate through a support arm. The cantilever beam is provided with 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; the vibration isolation component comprises a first horizontal support plate, a second horizontal support plate, a multi-layer isolation sleeve, and a support column, and the adjacent isolation sleeve interlayers are filled with elastic material. The device realizes the combination of static and dynamic measurements, and can capture rapidly changing torques and forces while maintaining high accuracy.

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 that takes both static and dynamic measurements into consideration. 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 crucial to ensuring the success of the mission. The aerospace field faces complex working environments and extreme operating conditions, which place 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 specific aerospace environments still face challenges.

[0003] Six-axis force sensors are widely used in various scientific and technological fields due to their highly integrated structure and excellent measurement performance. They typically consist of highly sensitive force sensors and complex signal processing circuits, converting mechanical forces into electrical signals for further analysis and application. However, conventional six-axis force sensors, both domestically and internationally, are complex and cumbersome, are relatively heavy, and cannot accommodate both static and dynamic measurements. Furthermore, they suffer from low measurement accuracy. 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 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 and dynamic measurements, including a measuring component and a vibration isolation component; the measuring component includes a base plate, a top plate and a cantilever beam; the two ends of the cantilever beam are fixedly connected to the base plate by two support rods, a support arm extends upward from the middle of the cantilever beam, a limiting groove is provided on the bottom surface of the top plate, and the top end of the support arm is clamped into the limiting groove, and a uniaxial strain gauge, a first biaxial strain gauge and a second biaxial strain gauge for static measurement are provided on the cantilever beam on the right side of the support arm, and 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 provided on the cantilever beam on the left side of the support arm, and 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 assembly 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 the interlayers of adjacent isolation sleeves are filled with elastic material, and the top and bottom of the isolation sleeve 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 assembly is fixedly connected to the first horizontal support plate.

[0006] The device comprises a measuring assembly in the upper half and a vibration isolation assembly in the lower half. The measuring assembly is fixed to the top of the vibration isolation assembly to ensure unaffected force transmission. The second horizontal support plate of the vibration isolation assembly is fixed to the base or mounting platform of the device, effectively reducing the impact of environmental vibration on the measuring assembly and improving the measurement accuracy and stability of the measuring assembly. Within the measuring assembly, the uniaxial strain gauge, the first biaxial strain gauge, and the second biaxial strain gauge are responsible for static measurement, while 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 each have their own sensitive measurement directions and only respond to forces in their most sensitive directions. Furthermore, 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 a force acts on the top plate of the measuring device, the cantilever beam bends and deforms under 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 changes. By measuring the corresponding change in resistance, the magnitude of the strain can be determined, which can then be used to measure the forces and moments 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 directions. Based on the piezoelectric effect, an electric charge is generated. The change in charge is converted into a voltage signal, which is then used to calculate the forces and moments 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 individually processed and output 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 X-type piezoelectric crystal, the first Y-type piezoelectric crystal, and the second Y-type piezoelectric crystal have relatively fast responses, typically in the microsecond range. The uniaxial strain gauge, the first biaxial strain gauge, and the second biaxial strain gauge have relatively slow responses, typically in the millisecond range. 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, while 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 shortcomings 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 shortcomings 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, realizing the combination of static measurement and dynamic measurement. While maintaining high precision, it can also capture rapidly changing torque and force; the structure is safe and reliable, the size of each component can be reasonably adjusted, and replacement is convenient; the vibration isolation component effectively reduces the influence of external vibration on the measurement accuracy of the measuring device, further ensuring the reliability of the measurement results; and ultimately, accurate measurement and output of six-dimensional force are achieved 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 torque 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 torque 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 torque in the Y direction 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. The X-direction, Y-direction, and Z-direction are mutually perpendicular. This structural 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 as needed. Taking the uniaxial strain gauge as an example, mechanical stress applied in the Z-direction will cause the resistance of the uniaxial strain gauge to change. By measuring the corresponding change in resistance, the magnitude of the strain can be determined, which is 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, 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, ensuring 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 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, and 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 then 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 via 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. The Wheatstone bridge can convert the resistance change of the strain gauge into a voltage change. A Wheatstone bridge typically consists of four resistors: R1, R2, R3, and R4. Strain gauges replace R1 and R2 and are connected to one diagonal of the Wheatstone bridge. The other two resistors, R3 and R4, are connected to the other diagonal of the bridge. When an external force acts on the strain gauge, causing the resistance to change, the Wheatstone bridge loses balance, generating a nonzero output voltage. This output voltage is proportional to the change in the strain gauge's resistance and can therefore be used to measure force and torque. Because the piezoelectric crystal directly generates a charge signal, it 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 amplifies the signal, increasing its amplitude and making it easier for subsequent circuitry to process. A low-pass filter removes high-frequency noise and interference from the signal. A high-pass filter removes low-frequency noise, such as static interference from the strain gauge, while retaining the high-frequency dynamic signal. The digital signal is processed by a 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 measurement assembly further includes a protective sleeve, which is mounted on the outside 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 preventing 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, bottom plate, first horizontal support plate, and second horizontal support plate are all circular plate-shaped structures, and the axes of the top plate, bottom plate, first horizontal support plate, second horizontal support plate, protective sleeve, isolation sleeve, and support arm are collinear. The upper surface of the top plate is marked with a detection contact area for the force to be measured. This arrangement is structurally sound, and the detection contact area is generally located in the center 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 easy to replace; the vibration isolation component effectively reduces the influence of external vibration on the measurement accuracy of the measuring device, further ensuring the reliability of the measurement results; and finally, accurate 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 A schematic diagram of the external structure of a multi-dimensional force measurement device that takes into account both static and dynamic measurements according to an embodiment of the present invention;

[0018] Figure 2 An exploded schematic diagram of a multi-dimensional force measurement device that takes into account both static and dynamic measurements according to an embodiment of the present invention;

[0019] Figure 3 A cross-sectional view of a multi-dimensional force measurement device that takes into account both static and dynamic measurements according to an embodiment of the present invention;

[0020] Figure 4 Schematic diagram of the structure of the cantilever beam in one embodiment of the present invention;

[0021] Figure 5 Schematic diagram of the structure of the measurement component in an embodiment of the present invention.

[0022] In the figure: 1. Base plate; 2. Top plate; 3. Cantilever beam; 4. Support rod; 5. Support arm; 6. Limiting 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

[0023] 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, in the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other.

[0024] In the description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance. It should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, removable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms based on specific circumstances.

[0025] 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 the embodiments.

[0026] The following is combined with Figures 1 to 5 Specific embodiments of the present invention are described in detail.

[0027] In one embodiment, a multi-dimensional force measurement device that takes into account both static and dynamic measurements 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 by two support rods 4, a support arm 5 extends upward from the middle of the cantilever beam 3, a limiting groove 6 is provided on the bottom surface of the top plate 2, and the top end of the support arm 5 is clamped into the limiting 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 provided 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 provided on the cantilever beam 3 on the left side of the support arm 5 The polarization directions are perpendicular to each other and are used to detect forces and moments in corresponding directions respectively; a signal processing circuit board 13 is provided on the base 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 assembly includes 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 sleeves 16 are collinear, and 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 base plate 1 of the measuring assembly is fixedly connected to the first horizontal support plate 14.

[0028] In this device, the upper half is a measuring component, and the lower half is a vibration isolation component. The measuring component is fixed to the top of the vibration isolation component to ensure that the transmission of force is not affected. The second horizontal support plate 15 of the vibration isolation component is fixed to the base or mounting 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 each have their own sensitive measurement direction and only respond to forces in their most sensitive direction. In addition, 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.

[0029] When a force acts on the top plate 2 of the measuring device, the cantilever beam 3 bends and deforms under the force. 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 changes. By measuring the corresponding resistance change, the magnitude of the strain can be determined, and then 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. Based on the piezoelectric effect, an electric charge is generated. The change in charge is converted into a voltage signal, which is then used to calculate the force and torque in the 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 individually processed and output through the signal processing circuit board 13, thereby obtaining independent output signals. The signal processing circuit board 13 is a highly integrated PCB board. 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.

[0030] The response time 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 at 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 at 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.

[0031] Specifically, the measurement assembly's base plate 1 is directly connected to the first horizontal support plate 14 of the vibration isolation assembly via multiple bolts. Four support columns 17 are located between a multi-layered isolation sleeve 16. The isolation sleeve 16 comprises three layers, separated by two interlayers of elastic material 18. These elastic materials can be silicone rubber or fluororubber. The elastic material 18 has a certain degree of viscosity, which strengthens the connection between the isolation sleeve 16 and the first and second horizontal support plates 14, 15. The cantilever beam 3 and support arm 5 can be made of stainless steel.

[0032] 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, realizing the combination of static measurement and dynamic measurement. While maintaining high precision, it can also capture rapidly changing torque and force; the structure is safe and reliable, the size of each component can be reasonably adjusted, and replacement is convenient; the vibration isolation component effectively reduces the influence of external vibration on the measurement accuracy of the measuring device, further ensuring the reliability of the measurement results; and ultimately, accurate measurement and output of six-dimensional force are achieved in an aerospace environment.

[0033] On the basis of the above embodiment, in a preferred embodiment, the direction of the cantilever beam 3 is parallel to the plane of the base 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. Measuring the force and torque 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, Y, and Z directions are mutually perpendicular. This arrangement is structurally 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, mechanical stress applied in the Z direction causes the resistance of the uniaxial strain gauge 7 to change. By measuring the corresponding change in resistance, the magnitude of the strain can be determined, which can then be 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, mechanical stress applied in the X direction causes the first Y-type piezoelectric crystal 11 to generate an electric charge. By measuring the corresponding change in charge, the force and torque in the X direction can be determined. 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 determines the polarization direction. The piezoelectric crystal is placed between electrodes, ensuring that the electrode arrangement generates 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. A power supply applies an appropriate voltage to the electrodes to generate a sufficiently strong electric field within 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 .

[0034] Based on 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, and the charge amplifier and the high-pass filter are connected in series to form a piezoelectric sheet signal conditioning subcircuit. The output of the strain gauge signal conditioning subcircuit and the output of the piezoelectric sheet signal conditioning subcircuit are connected in parallel to the input 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 then connected to the output interface. The outputs 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 of the strain gauge signal conditioning subcircuit via corresponding Wheatstone bridges. The outputs 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 of the piezoelectric sheet signal conditioning subcircuit. The outputs 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. The Wheatstone bridges can convert the resistance changes of the strain gauges into voltage changes. A Wheatstone bridge typically consists of four resistors: R1, R2, R3, and R4. Strain gauges replace R1 and R2 and are connected to one diagonal of the Wheatstone bridge. The other two resistors, R3 and R4, are connected to the other diagonal. When the strain gauges are subjected to an external force, causing their resistance to change, the Wheatstone bridge becomes unbalanced, generating a non-zero output voltage. This output voltage is proportional to the change in the strain gauge's resistance and can therefore be used to measure force and torque. Because the piezoelectric crystal directly generates a charge signal, this signal is very weak and susceptible to noise interference. Therefore, a charge amplifier is required for amplification. The amplifier amplifies the signal, increasing its amplitude and making it easier for subsequent circuitry to process. A low-pass filter removes high-frequency noise and interference from the signal, while a high-pass filter removes low-frequency noise, such as static interference from the strain gauges, while retaining the high-frequency dynamic signal. The digital signal is processed by a data acquisition system to obtain more accurate force and torque information. An RS485 interface is available as an output interface for transmitting the processed digital signal to external devices or systems.

[0035] Based on the above embodiment, in a preferred embodiment, the measuring assembly further includes a protective sleeve 19, which is mounted on the outside of the bottom plate 1 and the top plate 2, and has an 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. This configuration is structurally sound and improves the stability of the overall structure.

[0036] Based on the above embodiments, in a preferred embodiment, the top plate 2, bottom plate 1, first horizontal support plate 14, and second horizontal support plate 15 are all circular plate-like structures, and the axes of the top plate 2, bottom plate 1, first horizontal support plate 14, second horizontal support plate 15, protective sleeve 19, isolation sleeve 16, and support arm 5 are collinear; the upper surface of the top plate 2 is marked with a detection contact area for the force to be measured. This structural arrangement is reasonable. The detection contact area is generally located in the center area of ​​the top plate 2 and can be set as a scale line, a marking coil, or positioned and marked through a circle of positioning holes 20.

[0037] The above description is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions have been made with reference to the aforementioned embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents; and such modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments, and they should all be included in the scope of protection of the claims.

Claims

1. A multi-dimensional force measurement device that takes into account both static and dynamic measurements, 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); both ends of the cantilever beam (3) are fixedly connected to the bottom plate (1) through two support rods (4); a support arm (5) extends upward from the middle of the cantilever beam (3); a limiting groove (6) is provided on the bottom surface of the top plate (2); the top end of the support arm (5) is engaged with the limiting groove (6); a uniaxial strain gauge (7), a first biaxial strain gauge (8) and a second biaxial strain gauge (9) for static measurement are provided on the cantilever beam (3) on the right side of the support arm (5); the uniaxial strain gauge ( 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 the force and torque in the 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 provided on the cantilever beam (3) on the left side of the support arm (5), and 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 the force and torque in the corresponding directions; A signal processing circuit board (13) is provided on the bottom plate (1); a uniaxial strain gauge (7), a first biaxial strain gauge (8), a second biaxial strain gauge (9), an X-type piezoelectric crystal (10), a first Y-type piezoelectric crystal (11), and a second Y-type piezoelectric crystal (12) are respectively connected to the signal processing circuit board (13); The vibration isolation assembly 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 support plate (14).

2. The multi-dimensional force measurement device capable of both static 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 torque 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 torque 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 torque 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 capable of both static and dynamic measurement according to claim 2, characterized in that: 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 processed by the 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 and dynamic measurements 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 capable of 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 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 for the force to be measured.

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