Low-frequency micro-vibration sensing and actuating integrated device

Abstract

The application discloses a low-frequency micro-vibration sensing and actuating integrated device, which comprises a top component, a voice coil actuator, a low-frequency dynamic force sensor and a bottom component, the voice coil actuator comprises a magnetic steel and a voice coil, the voice coil is installed on the bottom component, the magnetic steel is installed on the top component, one end of the low-frequency dynamic force sensor is connected with the voice coil, and the other end of the low-frequency dynamic force sensor is connected with the magnetic steel; the low-frequency dynamic force sensor is coaxially connected with the voice coil actuator; the low-frequency dynamic force sensor comprises a semiconductor strain gauge as a measuring element, a polyurethane material as an elastic element and a composite full-bridge circuit as a measuring circuit. The low-frequency micro-vibration sensing and actuating integrated device effectively combines the low-frequency dynamic force sensor and the voice coil actuator together, can simultaneously provide two functions of low-frequency vibration measurement and actuating force output, improves sensor performance and actuator stability, thereby improves isolation performance of the device, can meet severe environmental requirements in space and has low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of spatial low-frequency measurement and active vibration isolation, and in particular relates to a low-frequency micro-vibration sensing and actuating integrated device. Background Art

[0002] During spacecraft in-orbit operations, the payloads carried by them are subject to the effects of space microvibration disturbances. Low-frequency microvibrations, such as those of flexible attachments, flexible solar panels, and optical camera sweeps, typically range in frequency from 0.01 to 10 Hz. These low-frequency microvibrations significantly impact key performance indicators of precision space payloads, including pointing accuracy, stability, and resolution. Therefore, research into low-frequency microvibration measurement and active vibration isolation technologies is crucial for ensuring the reliable operation of precision payloads.

[0003] Low-frequency dynamic force sensors are an important method for measuring low-frequency micro-vibrations. At present, low-frequency dynamic force sensors mainly include piezoelectric and resistive strain sensors. The signal generated by the piezoelectric sensor is weak and the output impedance is high. The high output impedance needs to be converted into a low output impedance and then amplified by charge before it can be collected. When performing static measurements, the amount of charge is easily lost, and after a period of time, the functional relationship between the amount of charge and pressure will change. Therefore, the lower the measured frequency, the more the output voltage sensitivity deviates from the ideal state, and the greater the error in sensitivity and phase angle. Strain sensors are mainly used to measure static and quasi-static forces, and are widely used because of their simple design and stable and reliable performance. However, there is still a problem of insufficient sensitivity in measuring dynamic forces. Therefore, there is an urgent need in this field for a device suitable for low-frequency micro-vibration measurement and active vibration isolation in space to ensure the reliable operation of precision loads in space. Summary of the Invention

[0004] In view of this, the present invention proposes a low-frequency micro-vibration sensing and actuation integrated device. The low-frequency dynamic force sensor adopts the strain measurement principle to convert the low-frequency dynamic force received into an electrical signal for strain acquisition. A semiconductor strain gauge with a higher sensitivity coefficient than an ordinary strain gauge is used as a measuring element, a polyurethane material with an elastic modulus much lower than that of metal is used as an elastic element, and a composite full-bridge circuit is used as a measuring circuit, which can effectively improve the sensitivity of the sensor and achieve accurate measurement of low-frequency signals of 0.01-10Hz. The voice coil actuator outputs the corresponding force according to the signal provided by the controller. The voice coil actuator has the advantages of fast response, high precision, low energy consumption, etc., and can achieve precise control of the force value. The present invention integrates the low-frequency dynamic force sensor with the voice coil actuator to achieve accurate measurement and response to the low-frequency dynamic force of the installation platform.

[0005] On the one hand, the present invention provides a low-frequency micro-vibration sensing and actuation integrated device, characterized in that it includes: a top component, a voice coil actuator, a low-frequency dynamic force sensor and a bottom component, the voice coil actuator includes a magnet and a voice coil, the voice coil is installed on the bottom component, the magnet is installed on the top component, one end of the low-frequency dynamic force sensor is connected to the voice coil, and the other end is connected to the magnet; the low-frequency dynamic force sensor is coaxially connected to the voice coil actuator; the low-frequency dynamic force sensor includes a semiconductor strain gauge as a measuring element, a polyurethane material as an elastic element, and a composite full-bridge circuit as a measuring circuit.

[0006] Furthermore, the voice coil is mounted on the bottom member via bolts, the magnet is mounted on the top member via bolts, one end of the low-frequency dynamic force sensor is connected to the voice coil via bolts, and the other end is connected to the magnet via epoxy glue.

[0007] Furthermore, the semiconductor strain gauge is a TP-5 semiconductor strain gauge made of single crystal silicon.

[0008] Furthermore, the outer diameter of the semiconductor strain gauge is 15 mm and the height is 30 mm.

[0009] Furthermore, the elastic modulus of the polyurethane material is 4.1×10 7 Pa.

[0010] Furthermore, the composite full-bridge circuit uses eight semiconductor strain gauges symmetrically pasted around the elastic element.

[0011] Furthermore, the magnetic steel includes a permanent magnet and a stator core, the permanent magnet is a NiFeB permanent magnet N42SH, and the stator core is stainless steel, steel grade 2Cr13.

[0012] Furthermore, the voice coil includes a coil and a voice coil frame. The coil adopts an annular multi-layer winding and is wound with high-strength enameled wire QY-2 / 220. The voice coil frame material is 6061 aluminum alloy.

[0013] Furthermore, the coil is connected to the magnet through the low-frequency dynamic force sensor, and the height H of the voice coil and the gap h between the voice coil and the magnet are designed according to vibration isolation requirements, thereby ensuring that the movement stroke of the voice coil actuator is h.

[0014] On the other hand, the present invention also provides an active vibration isolation device, which includes the low-frequency micro-vibration sensing and actuating integrated device of the present invention, a power supply, a signal conditioner, a real-time controller and a voice coil driver, wherein the power supply is used to provide power to the active vibration isolation device, the signal conditioner is data-connected to the low-frequency micro-vibration sensing and actuating integrated device and the real-time controller, the real-time controller is further electrically connected to the voice coil driver, and the voice coil driver is further electrically connected to the low-frequency micro-vibration sensing and actuating integrated device;

[0015] The working process of the active vibration isolation device is as follows: when the top component is disturbed by the dynamic force F, the low-frequency dynamic force sensor is deformed by the force, and the force value signal is converted into a voltage and transmitted to the signal conditioner; the signal conditioner outputs the signal to the real-time controller to collect the information of the force value F applied to the low-frequency dynamic force sensor in real time; the real-time controller outputs the control current to the voice coil driver through the calculation of the control algorithm, thereby driving the voice coil actuator to output the control force to control the vibration of the top component, so as to achieve a stable state of the top component.

[0016] A sensing and vibration isolation system consists of a sensor for measurement and an actuator for force output. Designing a vibration isolation system requires not only the structural design of each sensor and actuator, but also the design of their mounting locations. The present invention's integrated low-frequency micro-vibration sensing and actuation device effectively combines the sensor and actuator, providing both low-frequency vibration measurement and force output, facilitating the development of vibration isolation systems.

[0017] The low-frequency micro-vibration sensor and actuator designed in this invention can accurately measure low-frequency force information in the 0.01-10 Hz range and control the vibration of the mounting platform. This makes the invention have the following advantages in practical applications compared to existing technologies:

[0018] 1. Improve sensor performance: The device uses semiconductor strain gauges as measuring elements, polyurethane materials as elastic elements, and composite full-bridge circuits as measuring circuits, making the sensor sensitivity reach 0.33V / N and the measurement frequency reach 0.01Hz.

[0019] 2. Improve the vibration isolation performance of the device: The device can not only measure the force information of the installation platform, but also output the force value to actively isolate the installation platform from vibration. The polyurethane material connecting the sensor and the actuator has spring and damping characteristics, and can also perform passive vibration isolation on the installation platform.

[0020] 3. Improve the stability of the actuator: The magnet and coil parts of the voice coil actuator are connected by the elastic element of the sensor, which has great damping. It can improve the passive vibration isolation performance, reduce the difficulty of active vibration isolation algorithm design, and reduce the possibility of failure.

[0021] 4. Improve the environmental adaptability of the device: All materials in the device can adapt to the environmental requirements of -45 to +100 ° C and can meet the severe environmental requirements of space.

[0022] 5. Reduce costs: The semiconductor strain gauges used in the sensor are similar in price to ordinary strain gauges. The material and processing costs of polyurethane elastic elements are much lower than those of metal elastic elements. The magnets and coils used in the voice coil actuator are both made with mature processes. Therefore, the cost of the low-frequency micro-vibration sensing and actuation integrated device can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a perspective view of the composition and connection method of the low-frequency sensing and actuating integrated device of the present invention.

[0024] Figure 2 It is a structural schematic diagram of the low-frequency sensing and actuating integrated device of the present invention.

[0025] Figure 3 These are the front view and sectional view of the low-frequency sensing and actuating integrated device of the present invention.

[0026] Figure 4 It is a structural schematic diagram of the low-frequency dynamic force sensor of the present invention.

[0027] Figure 5 It is a schematic diagram of the elastic element in the low-frequency dynamic force sensor of the present invention.

[0028] Figure 6 This is a schematic diagram of the pasting position of the semiconductor strain gauge in the present invention.

[0029] Figure 7 This is a schematic diagram of the semiconductor strain gauge wiring circuit in the present invention.

[0030] Figure 8 It is a structural diagram of the magnetic steel in the present invention.

[0031] Figure 9 These are the main view and cross-sectional view of the magnetic steel in the present invention.

[0032] Figure 10 It is a structural schematic diagram of the voice coil in the present invention.

[0033] Figure 11 2 are the front view and cross-sectional view of the voice coil in the present invention.

[0034] Figure 12 It is a design position diagram of the voice coil actuator of the present invention.

[0035] Figure 13 It is a schematic diagram of the working process of the active vibration isolation device including the low-frequency micro-vibration sensing and actuating integrated device of the present invention.

[0036] In the figure: 1-stator core, 2-permanent magnet, 3-coil, 4-voice coil frame, 5-bottom member, 6-elastic element, 7-semiconductor strain gauge, 8-top member. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in more detail below with reference to the accompanying drawings, but the present invention is not limited thereto.

[0038] The present invention designs a low-frequency dynamic force sensor based on the strain measurement principle and a voice coil actuator based on the electromagnetic principle. The low-frequency dynamic force sensor and the voice coil actuator are designed as an integrated structure, which can also provide force value output during the dynamic force measurement process.

[0039] The structural perspective diagram of the low-frequency micro-vibration sensing and actuating integrated device designed by the present invention is as follows: Figure 1 As shown. The low-frequency micro-vibration sensing and actuation integrated device includes a voice coil actuator and a low-frequency dynamic force sensor. The voice coil actuator includes a magnet and a voice coil, and the magnet mainly includes a stator core 1 and a permanent magnet 2. The voice coil mainly includes a coil 3 and a voice coil frame 4. The voice coil frame is mounted on the bottom component 5 by bolts, and the stator core of the magnet is mounted on the top component 8 by bolts. The low-frequency dynamic force sensor mainly includes an elastic element 6 and a semiconductor strain gauge 7. One end of the elastic element 6 is connected to the voice coil frame by bolts, and the other end is connected to the magnet permanent magnet by epoxy glue. The voice coil actuator is coaxially connected to the force sensor. The force sensor can measure the dynamic force F exerted on the top component. The elastic element of the force sensor has the characteristics of a spring and damping, and can provide passive vibration isolation for the top plate. The voice coil actuator can actively isolate the top component from vibration. The structure of the low-frequency sensing and actuation integrated device is shown as follows. Figure 2-3 shown.

[0040] In one embodiment, the main structure of the low-frequency dynamic force sensor is a cylindrical elastic element, and a strain gauge is attached to the surface of the elastic element. As the elastic element is deformed by force, the sensitive grid of the strain gauge also undergoes the same deformation, causing its resistance to change accordingly. This resistance change is proportional to the strain of the elastic element. This resistance change is converted into a voltage change through a bridge measurement circuit, thereby obtaining the magnitude of the strain of the elastic element. Finally, the magnitude of the force applied to the elastic element is calculated using Hooke's law. The structure of the low-frequency dynamic force sensor and the elastic element entity are as follows: Figure 4-5 shown.

[0041] In order to improve the sensitivity of the low-frequency dynamic force sensor, polyurethane material is used as the elastic element of the low-frequency dynamic force sensor, and its elastic modulus is 4.1×10 7 Pa is one thousandth of the elastic modulus of metal. Polyurethane material has higher elasticity and greater damping than metal material, which can effectively provide passive vibration isolation performance. In order to facilitate the attachment of strain gauges, the outer diameter is designed to be 15mm and the height is designed to be 30mm. Elastomers processed by polyurethane materials such as Figure 4 shown.

[0042] Traditional strain sensors primarily use metal strain gauges as measuring elements, which have low sensitivity coefficients, long response times, and are incapable of dynamic measurements. In a preferred embodiment, a low-frequency dynamic force sensor uses a TP-5 semiconductor strain gauge made of single-crystal silicon. Detailed parameters are shown in Table 1. Semiconductor strain gauges are sensitive elements made using the piezoresistive effect of semiconductor single-crystal silicon. They offer the advantages of low mechanical hysteresis, small size, and low power consumption. Compared to traditional metal strain gauges, semiconductor strain gauges have better temperature stability and a wider operating temperature range, operating within a range of -55°C to 200°C. Semiconductor strain gauges have a faster response time than metal strain gauges and can reflect strain changes in an object within microseconds. They also have a high sensitivity coefficient, which is 50 times that of ordinary metal strain gauges.

[0043] Table 1 Parameters of TP-5 semiconductor strain gauge

[0044]

[0045] The measurement circuit adopts a composite full-bridge connection method, using 8 semiconductor strain gauges symmetrically pasted around the elastic body. This bridge circuit can maximize the sensitivity of the sensor and effectively reduce the strain error caused by eccentric load, and also has a temperature compensation function. The strain gauge pasting position and wiring method are as follows Figure 6-7 shown.

[0046] It can be seen from the strain measurement principle that the strain ε of a single strain gauge is 11 The total strain measured using a full-bridge circuit is consistent with The relationship between them is:

[0047]

[0048] Among them, ε 11 ,ε 12 ,ε 21 ,ε 22 ,ε 31 ,ε 32 ,ε 41 ,ε 42 They are strain gauge R 11 ,R 12 ,R 21 ,R 22 ,R 31 ,R 32 ,R 41 ,R 42 The strain value; ε T is the strain value corresponding to the temperature; is the measured value of the full bridge; μ is the Poisson's ratio of the elastic material of the low-frequency dynamic force sensor. From formula (1), it can be seen that the strain value ε corresponding to the temperature isT With full bridge measurement Don't care, full bridge measurement value Much larger than the value measured using a single strain gauge ε 11 Therefore, the measurement value obtained by using the composite full-bridge connection method can not only effectively improve the sensitivity of the sensor but also suppress the influence of the ambient temperature.

[0049] The voice coil actuator adopts a cylindrical linear voice coil motor solution, which mainly consists of two parts: magnet and voice coil. Its structure is as follows Figure 5-7 As shown. The magnetic steel adopts an inner cylindrical magnetic steel structure, which mainly includes permanent magnets and stator cores. The cylindrical permanent magnets are glued to the magnetic steel slots with epoxy resin glue. They are characterized by axial magnetization, compact structure, and firmness, which is beneficial to improving the structural strength of the magnetic steel. The permanent magnet adopts high-performance NiFeBo permanent magnet N42SH, which has a high magnetic energy product and is beneficial to improving the power density of the motor. The magnetic steel core adopts magnetic conductive stainless steel, steel grade 2Cr13, which can ensure both magnetic conductivity and structural strength. The structure of the magnetic steel is as shown Figure 8-9 shown.

[0050] The voice coil mainly consists of a coil and a voice coil frame. The coil adopts a toroidal multi-layer winding, which is wound with high-strength enameled wire QY-2 / 220, and the voice coil frame material is 6061 aluminum alloy. The voice coil is connected to the magnet through a force sensor. The height H of the voice coil part and the gap h between the voice coil and the magnet can be designed according to the vibration isolation requirements to ensure the movement range of the voice coil actuator is h. The structure of the voice coil is as follows Figure 10-11 As shown, the design position of the voice coil actuator is as follows Figure 12 shown.

[0051] The working process of the low-frequency micro-vibration sensing and actuation integrated device is as follows: Figure 13 As shown in the figure, when the top member is disturbed by a dynamic force F, the low-frequency dynamic force sensor deforms, converting the force signal into a voltage and transmitting it to the signal conditioner. The signal conditioner outputs the signal to the real-time controller, which collects information about the force F applied to the low-frequency dynamic force sensor in real time. The real-time controller, through calculations using a control algorithm, outputs a control current to the voice coil actuator, which drives the voice coil actuator to output a control force to control the vibration of the top member, thereby achieving a stable state for the top member.

[0052] The present invention also provides an active vibration isolation device, comprising the above-mentioned low-frequency micro-vibration sensing and actuating integrated device, a power supply, a signal conditioner, a real-time controller, and a voice coil driver. The power supply is used to provide power to the active vibration isolation device. The signal conditioner is data-connected to the low-frequency micro-vibration sensing and actuating integrated device and the real-time controller. The real-time controller is further electrically connected to the voice coil driver, and the voice coil driver is further electrically connected to the low-frequency micro-vibration sensing and actuating integrated device.

[0053] The working process of the active vibration isolation device is as follows: when the top component is disturbed by the dynamic force F, the low-frequency dynamic force sensor is deformed by the force, and the force value signal is converted into a voltage and transmitted to the signal conditioner; the signal conditioner outputs the signal to the real-time controller to collect the information of the force value F applied to the low-frequency dynamic force sensor in real time; the real-time controller outputs the control current to the voice coil driver through the calculation of the control algorithm, thereby driving the voice coil actuator to output the control force to control the vibration of the top component, so as to achieve a stable state of the top component, such as Figure 13 shown.

[0054] It should be noted that the above-described embodiments are merely preferred embodiments of the present invention. Persons skilled in the art will appreciate that various modifications, improvements, and equivalent substitutions may be made to the present invention without departing from the principles of the present invention, and such modifications, improvements, and equivalent substitutions are deemed to fall within the scope of protection of the claims of the present invention.

Claims

1. A low-frequency micro-vibration sensing and actuating integrated device, characterized in that: include: A top member, a voice coil actuator, a low-frequency dynamic force sensor, and a bottom member. The voice coil actuator includes a magnet and a voice coil. The voice coil is mounted on the bottom member, and the magnet is mounted on the top member. One end of the low-frequency dynamic force sensor is connected to the voice coil, and the other end is connected to the magnet. The low-frequency dynamic force sensor is coaxially connected to the voice coil actuator. The low-frequency dynamic force sensor includes a semiconductor strain gauge as a measuring element, a polyurethane material as an elastic element, and a composite full-bridge circuit as a measuring circuit. The magnetic steel includes a stator core (1) and a permanent magnet (2); the voice coil includes a coil (3) and a voice coil frame (4); the voice coil frame is mounted on a bottom member (5) by bolts, and the stator core of the magnetic steel is mounted on a top member (8) by bolts; one end of the elastic element (6) is connected to the voice coil frame by bolts, and the other end is connected to the permanent magnet of the magnetic steel by epoxy glue; The main structure of the low-frequency dynamic force sensor is a cylindrical elastic element, and the strain gauge is attached to the surface of the elastic element; The voice coil actuator uses a cylindrical linear voice coil motor; The magnetic steel adopts an inner cylindrical magnetic steel structure, and the cylindrical permanent magnet is glued into the magnetic steel slot with epoxy resin glue; The coil is connected to the magnet through the low-frequency dynamic force sensor. The height H of the voice coil and the gap h between the voice coil and the magnet are designed according to vibration isolation requirements to ensure that the movement stroke of the voice coil actuator is h.

2. The low-frequency micro-vibration sensing and actuating integrated device according to claim 1, characterized in that: The voice coil is mounted on the bottom member via bolts, the magnet is mounted on the top member via bolts, one end of the low-frequency dynamic force sensor is connected to the voice coil via bolts, and the other end is connected to the magnet via epoxy glue.

3. The low-frequency micro-vibration sensing and actuating integrated device according to claim 1, characterized in that: The semiconductor strain gauge is a TP-5 semiconductor strain gauge made of single crystal silicon.

4. The low-frequency micro-vibration sensing and actuating integrated device according to claim 1, characterized in that: The semiconductor strain gauge has an outer diameter of 15 mm and a height of 30 mm.

5. The low-frequency micro-vibration sensing and actuating integrated device according to claim 1, characterized in that: The elastic modulus of the polyurethane material is 4.1×10 7 Pa.

6. The low-frequency micro-vibration sensing and actuating integrated device according to claim 1, characterized in that: The composite full-bridge circuit uses eight semiconductor strain gauges symmetrically pasted around the elastic element.

7. The low-frequency micro-vibration sensing and actuating integrated device according to claim 1, characterized in that: The magnetic steel includes a permanent magnet and a stator core. The permanent magnet is a NiFeB permanent magnet N42SH, and the stator core is stainless steel with a steel grade of 2Cr13.

8. The low-frequency micro-vibration sensing and actuating integrated device according to claim 1, characterized in that: The voice coil includes a coil and a voice coil frame. The coil adopts an annular multi-layer winding and is wound with high-strength enameled wire QY-2 / 220. The voice coil frame material is 6061 aluminum alloy.

9. An active vibration isolation device, comprising the low-frequency micro-vibration sensing and actuating integrated device according to claim 1, a power supply, a signal conditioner, a real-time controller, and a voice coil driver, wherein the power supply is used to provide power to the active vibration isolation device, the signal conditioner is data-connected to the low-frequency micro-vibration sensing and actuating integrated device and the real-time controller, the real-time controller is further electrically connected to the voice coil driver, and the voice coil driver is further electrically connected to the low-frequency micro-vibration sensing and actuating integrated device; The working process of the active vibration isolation device is as follows: when the top component is disturbed by the dynamic force F, the low-frequency dynamic force sensor is deformed by the force, and the force value signal is converted into a voltage and transmitted to the signal conditioner; the signal conditioner outputs the signal to the real-time controller to collect information on the force value F applied to the low-frequency dynamic force sensor in real time; the real-time controller outputs the control current to the voice coil driver through the calculation of the control algorithm, thereby driving the voice coil actuator to output the control force to control the vibration of the top component, so as to achieve a stable state of the top component.

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