Self-adaptive adjusting device capable of buffering torsional vibration frequency drift for scanning grating micromirror
By using adaptive adjustment devices with components such as weight rods and bending stiffness adjustment rods in scanning grating micromirrors, the torsion frequency drift problem caused by the degradation of the system's torsional stiffness is solved, ensuring that the micromirror is in a high-frequency working state. Torsional stiffness and impact resistance.
Patent Information
- Application Number
- CN202421091399.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-20
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-05-20
AI Technical Summary
In the high-frequency torsional resonance working environment, the system's torsional stiffness will deteriorate seriously, resulting in a drop in the torsional resonance frequency. The frequency tracking circuit is required to adjust the current frequency of the electromagnetic drive to track the torsional vibration frequency, but this may lead to electromagnetic force. The excitation frequency approaches the first-order main vibration model, affecting the impact vibration resistance of the structure.
Design an adaptive adjustment device including a weight rod, a bending stiffness adjustment rod, an elliptical hole support and a high-damping shrapnel. Through the cooperation of the bending stiffness adjustment rod and a high-damping shrapnel, the anti-torsion of the micromirror system is automatically adjusted. Inertia and bending stiffness avoid the frequency tracking circuit adjusting the electromagnetic excitation frequency, thereby buffering the torsional vibration frequency drift.
Without changing the torsional stiffness, the bending stiffness and torsional moment of inertia of the micromirror system are improved, and the first-order main vibration mode is adjusted to the desired torsional resonant vibration mode, and the frequency of the first-order and second-order vibration modes is opened. , prevent the frequency tracking circuit from failing after changing frequency, automatically buffer torsional frequency drift, and enhance the impact vibration resistance.
Smart Images
Figure CN222213071U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of spectrum analysis, in particular to an adaptive regulating device for a scanning grating micromirror capable of buffering torsional vibration frequency drift. Background Art
[0002] A scanning grating micromirror is a miniature optical spectroscopic device that integrates a grating on a scanning micromirror and has both spectroscopic and scanning functions. Usually, the central mirror plate of the scanning grating micromirror integrates a driving coil and an angle sensing coil, and is suspended to a fixed frame by a pair of folded beams. The coils are respectively led out to corresponding pads through the folded beams to achieve electrical connection with the outside. Therefore, the resonant frequency and scanning angle of the entire device are related to the torsional stiffness of the system (i.e., the torsional stiffness of the folded beam). In theory, the realization of its function requires that the torsional vibration be the first-order principal vibration mode. However, the current structural feature often results in the torsional vibration of the device not being its first-order principal vibration mode, and the up and down translation becoming its first-order principal vibration mode. At the same time, because the frequencies of the first-order and second-order torsional vibrations are close to each other, there is also a probability of vibration mode jumping.
[0003] When the scanning micromirror is in a high-frequency torsional resonance working environment for a long time, the torsional stiffness of the system will seriously degrade, causing its torsional resonance frequency to decrease. Therefore, it is necessary to design a special frequency tracking circuit. According to the frequency drift, the current frequency of the electromagnetic drive is adjusted, that is, the electromagnetic force excitation frequency is changed to make it consistent with the decreasing torsional vibration mode frequency. However, this also means that the electromagnetic force excitation frequency is further approaching the first-order principal vibration mode, and the residual resultant force in the translational direction of the electromagnetic force may induce resonance under the first-order translational vibration mode, which has a great adverse effect on the structure's ability to resist impact vibration.
[0004] Therefore, it is necessary to design an adaptive buffer device for the resonant frequency drift of the scanning grating micromirror to avoid designing a frequency tracking circuit to adjust the electromagnetic force excitation frequency in order to solve the above technical problems. Utility Model Content
[0005] The utility model aims to provide an adaptive adjustment device for a scanning grating micromirror which can buffer the torsional vibration frequency drift, adjust the vibration mode distribution of each order of the scanning grating micromirror system, and ensure that the micromirror can automatically buffer the possible torsional vibration frequency drift when the torsional stiffness decays under the high-frequency torsional long-term working state.
[0006] To achieve the above-mentioned purpose, the utility model provides an adaptive adjustment device for a scanning grating micromirror that can buffer torsional vibration frequency drift, comprising an attached weight rod, a bending stiffness adjustment rod, an elliptical hole support, a fixed frame and a high-damping spring piece, the attached weight rod and the bending stiffness adjustment rod are fixedly connected via the high-damping spring piece, the bending stiffness adjustment rod is plug-connected to the elliptical hole support, the elliptical hole support is arranged at the center position of the lower edge of the fixed frame, and the bending stiffness adjustment rod is fixed to the back of the central mirror plate.
[0007] Preferably, the end of the bending stiffness adjustment rod is a round rod, the elliptical hole support is provided with an elliptical hole for allowing the round rod to pass through and rotate, and the diameter of the round rod matches the minor axis length of the elliptical hole.
[0008] Preferably, the high damping spring sheet is repeatedly folded in one dimension to form a folded sheet, and damping material is smeared and adhered between the folded sheets.
[0009] Preferably, torsion beams are provided on both sides of the interior of the fixed frame, and the torsion beams are sleeved on the back side of the central mirror plate.
[0010] Preferably, the major axis of the elliptical hole is parallel to the fixed frame.
[0011] Therefore, the utility model adopts the above-mentioned scanning grating micromirror to buffer the torsional vibration frequency drift adaptive adjustment device, which has the following beneficial effects:
[0012] (1) The utility model can improve the bending stiffness of the micromirror system in the vertical direction without changing the torsional stiffness of the micromirror system by constraining the bending stiffness adjustment rod in the vertical direction; by setting the additional weight rod, the torsional moment of inertia is increased, thereby adjusting the first-order main vibration mode of the system to the desired torsional resonance vibration mode, and widening the frequencies of the first-order and second-order vibration modes, thereby preventing the risk of failure of the frequency tracking circuit after the frequency is changed to be closer to the translation vibration mode;
[0013] (2) The utility model provides an auxiliary weight rod that can adaptively change its position through a high-damping spring sheet. The rotational inertia of the auxiliary weight rod is automatically adjusted through the change of centrifugal force during frequency drift, thereby offsetting the attenuation effect of torsional stiffness during long-term high-frequency operation and buffering possible frequency drift of the micromirror system.
[0014] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a structural schematic diagram of an adaptive adjustment device for a scanning grating micromirror capable of buffering torsional vibration frequency drift in the utility model;
[0016] Figure 2This is a connection diagram of a fixed bracket of an adaptive adjustment device for a scanning grating micromirror capable of buffering torsional vibration frequency drift according to the utility model;
[0017] Figure 3 This is a schematic diagram of the connection between the weight-attached rod and the bending stiffness adjustment rod of an adaptive adjustment device for a scanning grating micromirror capable of buffering torsional vibration frequency drift according to the utility model;
[0018] Figure 4 It is a schematic diagram of an elliptical hole support of an adaptive adjustment device for a scanning grating micromirror capable of buffering torsional vibration frequency drift according to the utility model;
[0019] Reference numerals:
[0020] 1. Attached weight rod; 2. Bending stiffness adjustment rod; 3. Elliptical hole support; 31. Elliptical hole; 4. High damping spring; 5. Fixed frame; 6. Torsion center axis; 7. Torsion beam; 8. Center mirror plate. DETAILED DESCRIPTION
[0021] The technical solution of the utility model is further described below through the accompanying drawings and embodiments.
[0022] Unless otherwise defined, technical or scientific terms used in the present invention should have the common meanings understood by persons having ordinary skills in the field to which the present invention belongs.
[0023] The words "include" or "comprises" and the like used in the present invention mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of also including other elements. The orientation or position relationship indicated by the terms "inside", "outside", "upper", "lower", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. When the absolute position of the described object changes, the relative position relationship may also change accordingly. In the present invention, unless otherwise clearly specified and limited, the terms "attachment" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.
[0024] As attached Figures 1 to 4As shown, the utility model discloses that the utility model provides an adaptive adjustment device for a scanning grating micromirror that can buffer the torsional vibration frequency drift, including a weight-attached rod 1, a bending stiffness adjustment rod 2, an elliptical hole support 3, a fixed frame 5 and a high-damping spring 4. The weight-attached rod 1 is fixedly connected to the bending stiffness adjustment rod 2 through the high-damping spring 4, the bending stiffness adjustment rod 2 is plug-connected to the elliptical hole support 3, the elliptical hole support 3 is arranged at the center of the lower edge of the fixed frame 5, and the bending stiffness adjustment rod 2 is fixed to the back of the central mirror plate 8 of the micromirror system. The high-damping spring 4 realizes the spring function in a single-dimensional repeated folding form, and the high-frequency dynamic response is suppressed by applying and pasting damping material between the folded pieces; the inner sides of the fixed frame 5 are provided with torsion beams 7, and the torsion beams 7 are sleeved on the back of the central mirror plate 8 of the micromirror system.
[0025] The end of the bending stiffness adjustment rod 2 is a round rod, and the elliptical hole support 3 is provided with an elliptical hole 31 for the round rod to pass through and rotate. The diameter of the round rod matches the length of the minor axis of the elliptical hole 31, and the length of the major axis of the elliptical hole 31 is greater than the diameter of the round rod. The major axis of the elliptical hole 31 is parallel to the fixed frame 5. Therefore, the round rod can rotate freely in the elliptical hole 31, and the elliptical hole 31 provides stable support in the up and down translation direction; the elliptical hole 31 constrains the vertical direction of the round rod, increases the bending stiffness of the micromirror system without changing its torsional stiffness, and the weighted rod 1 increases the torsional moment of inertia of the micromirror system, so that the torsional vibration mode is adjusted to the desired first-order main vibration mode, and the up and down translation vibration mode is adjusted to the second-order vibration mode, while pulling apart the frequencies of the first-order and second-order vibration modes to prevent frequency transitions, and also avoid the risk of unexpected resonance that may occur when the electromagnetic excitation frequency is correspondingly lowered after the torsional stiffness is degraded due to the long-term high-frequency operation of the original micromirror structure and the frequency drift of the related torsional vibration mode occurs.
[0026] At the same time, the weight rod 1 can adjust its position based on the high damping spring 4, and adaptively change the moment of inertia of the micromirror system to resist torsion. When the weight rod 1 deviates from the resonant state, the centrifugal force peak value automatically decreases, and the high damping spring 4 pulls it back toward the central torsion axis 6. The high damping spring 4 has a large damping, which will absorb and block the high-frequency dynamic response of the weight rod 1 (the centrifugal force fluctuates in each torsion cycle, and the high-frequency dynamic response will be damped and filtered), but it will not affect the rebound of the weight rod 1 caused by the decrease in the amplitude and mean of the centrifugal force. The calculation formula of the torsional resonance frequency f of the micromirror system is as follows:
[0027]
[0028] Where, f is the torsional resonance frequency of the micromirror system formed by the grating device connected to the frame through the torsion beam, K m —The torsional stiffness of the micromirror system is mainly related to the torsional stiffness of the torsional beam, which can be calculated by looking up the shape and size of the torsional beam. As the high-frequency working time of the system accumulates, this value will decay due to material fatigue degradation.m —The moment of inertia of the micromirror system. The moment of inertia of the micromirror system generally ignores the contribution of the torsion beam between the micromirror and the outer frame, that is, it is mainly composed of the moment of inertia J of the central grating mirror plate. F and the moment of inertia of the weighted rod J r The relationship between them is:
[0029] J m =J F +J r
[0030] If the central grating mirror plate is a rectangular plate with a thickness of t, a length of l and a width of w, and a density of ρ F , the moment of inertia of the central grating mirror plate around the torsion axis J F It can be calculated by the following formula:
[0031]
[0032] If the mass of a single weight rod 1 is m and the distance from the central torsion axis 6 of the micromirror is r, then the total moment of inertia of the two weight rods 1 relative to the central torsion axis 6 is J r =2mr 2 .
[0033] In general, when the system torsional stiffness K m When the attenuation is very large, the torsional resonance frequency f of the micromirror system will deviate from the frequency of the torsional excitation force. Since torsional resonance no longer occurs, the torsional vibration amplitude of the overall structure that deviates from the resonant response will be sharply weakened. Due to the change in the amplitude and mean of the centrifugal force, the weight rod 1 rebounds to a new position to achieve balance, which will shorten the distance r from the torsional axis 6 of the micromirror center, and the moment of inertia J of the weight rod r is related to the square of r, so J r will be significantly reduced. Compared with the case where the moment of inertia of the micromirror system is fixed, the moment of inertia J of the micromirror system with the adjustable weight rod 1 is m Will follow K m The attenuation also decreases synchronously. Therefore, in the long-term torsional resonance high-frequency working environment of the system, the torsional stiffness K m After obvious attenuation, the designed adaptive weight rod 1 adjustment device will automatically reduce the system rotation inertia, thereby buffering the excessive drift of the torsional resonance frequency that may occur.
[0034] Therefore, the utility model adopts the above-mentioned adaptive adjustment device for scanning grating micromirror to buffer torsional vibration frequency drift, adjusts the vibration mode distribution of each order of scanning grating micromirror system, and ensures that the micromirror can automatically buffer the possible torsional vibration frequency drift when the torsional stiffness decays under high-frequency torsion long-term working state.
[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that they can still modify or replace the technical solution of the utility model with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the utility model.
Claims
1. An adaptive adjustment device for a scanning grating micromirror capable of buffering torsional vibration frequency drift, comprising a weight rod, a bending stiffness adjustment rod, an elliptical hole support, a fixed frame and a high damping spring, characterized in that: The additional weight rod is fixedly connected to the bending stiffness adjustment rod through the high damping spring piece, the bending stiffness adjustment rod is plug-connected to the elliptical hole support, the elliptical hole support is arranged at the center position of the lower edge of the fixed frame, and the bending stiffness adjustment rod is fixed on the back of the central mirror plate.
2. The adaptive adjustment device for a scanning grating micromirror capable of buffering torsional vibration frequency drift according to claim 1, characterized in that: The end of the bending stiffness adjustment rod is a round rod, and the elliptical hole support is provided with an elliptical hole for the round rod to pass through and rotate, and the diameter of the round rod matches the minor axis length of the elliptical hole.
3. The adaptive adjustment device for a scanning grating micromirror capable of buffering torsional frequency drift according to claim 1, characterized in that: The high damping spring sheet is repeatedly folded in one dimension to form a folded sheet, and damping material is smeared and pasted between the folded sheets.
4. The adaptive adjustment device for a scanning grating micromirror capable of buffering torsional frequency drift according to claim 1, characterized in that: Torsion beams are arranged on both sides of the interior of the fixed frame, and the torsion beams are sleeved on the back side of the central mirror plate.
5. The adaptive adjustment device for a scanning grating micromirror capable of buffering torsional frequency drift according to claim 2, characterized in that: The major axis of the elliptical hole is parallel to the fixed frame.