Fast reflecting mirror based on multi-degree-of-freedom displacement measurement

Abstract

The invention relates to the technical field of fast reflecting mirrors, in particular to a fast reflecting mirror based on multi-degree-of-freedom displacement measurement, and the fast reflecting mirror comprises a first sensor module which comprises at least two groups of first sensors and is used for collecting a plurality of inclination angle signals of a lens of the fast reflecting mirror; the second sensor module comprises at least two groups of second sensors, and the second sensors are used for collecting a plurality of translation quantity signals of the fast steering mirror lens; the fusion module obtains an inclination angle according to the plurality of inclination angle signals, and obtains a translation amount according to the plurality of translation amount signals; the control module generates a feedback item according to the inclination angle, generates a feed-forward item according to the translation amount, and obtains the angle correction amount according to the feedback item and the feed-forward item. Synchronous high-precision measurement of inclination and translation of the mirror surface is realized through multi-sensor layout, and the response speed and the control precision of the system are effectively improved by combining a signal fusion algorithm and a feedforward-feedback composite control strategy.

Description

Technical Field

[0001] This invention relates to the field of fast-reflection mirror technology, and more specifically to a fast-reflection mirror based on multi-degree-of-freedom displacement measurement. Background Technology

[0002] With the development of technologies such as lidar, adaptive optics, precision measurement, and high-end imaging, fast reflectors (or "fast mirrors") have become crucial actuators for achieving high-speed and precise beam deflection, and are widely used in laser scanning, beam stabilization, and galvanometer systems. To meet the application requirements of high-bandwidth and high-precision control, fast mirrors have gradually become the mainstream driving method for their fast response speed, simple structure, and lack of mechanical contact.

[0003] In existing technologies, the attitude control of fast-reflecting mirrors largely relies on feedback from a single sensor, typically using closed-loop control based on the measurement of the mirror's tilt angle. However, in actual operation, the motion of the mirror is not always purely rotational; it is often accompanied by minute translational motion. This translational motion can lead to inaccurate angle error identification, thus affecting the system's control accuracy and dynamic response performance. Furthermore, most existing systems lack effective compensation methods for translational disturbances, and the control algorithms do not fully utilize the multi-degree-of-freedom motion information of the mirror surface, limiting their application effectiveness in high-speed, high-precision control scenarios. Summary of the Invention

[0004] (I) Purpose of the Invention

[0005] The purpose of this invention is to provide a fast-reflecting mirror based on multi-degree-of-freedom displacement measurement that achieves synchronous high-precision measurement of mirror tilt and translation through a multi-sensor layout, and effectively improves the system's response speed and control accuracy by combining a signal fusion algorithm and a feedforward-feedback composite control strategy.

[0006] (2) Technical solution

[0007] To address the aforementioned problems, this invention provides a fast-reflecting mirror based on multi-degree-of-freedom displacement measurement, comprising: a first sensor module, a second sensor module, a fusion module, and a control module;

[0008] The first sensor module and the second sensor module are connected to the fusion module, and the fusion module is connected to the control module;

[0009] The first sensor module includes at least two sets of first sensors, and the first sensor module is used to acquire multiple tilt angle signals of the fast-reflecting mirror lens;

[0010] The second sensor module includes at least two sets of second sensors, which are used to acquire multiple translation signals of the fast-reflecting mirror lens;

[0011] The fusion module obtains the tilt angle based on multiple tilt angle signals and the translation amount based on multiple translation amount signals;

[0012] The control module generates a feedback term based on the tilt angle, generates a feedforward term based on the translation amount, and obtains the angle correction amount based on the feedback term and the feedforward term.

[0013] In another aspect of the present invention, preferably, the plurality of tilt angle signals include a first tilt angle signal, a second tilt angle signal, a third tilt angle signal, and a fourth tilt angle signal;

[0014] The fusion module obtains the tilt angle based on multiple tilt angle signals, including:

[0015] The difference between the first tilt angle signal and the second tilt angle signal is multiplied by a first adjustment coefficient to obtain the first signal difference.

[0016] The difference between the third tilt angle signal and the fourth tilt angle signal is multiplied by the second adjustment coefficient to obtain the second signal difference.

[0017] The tilt angle is obtained based on the first signal difference and the second signal difference.

[0018] In another aspect of the present invention, preferably, obtaining the tilt angle based on the first signal difference and the second signal difference includes calculating the tilt angle using the following formula:

[0019] θ = k1·(A1-A2) + k2·(A3-A4)

[0020] Where θ represents the tilt angle, k1 represents the first adjustment coefficient, k2 represents the second adjustment coefficient, and A1, A2, A3, and A4 represent the first tilt angle signal, the second tilt angle signal, the third tilt angle signal, and the fourth tilt angle signal, respectively.

[0021] In another aspect of the present invention, preferably, the plurality of translation signals include a first translation signal and a second translation signal, wherein the first translation signal and the second translation signal respectively come from two sets of second sensors;

[0022] The step of obtaining the translation amount based on multiple translation amount signals includes:

[0023] The translation amount is obtained by multiplying the third adjustment coefficient by the sum of the first and second translation signals.

[0024] In another aspect of the invention, preferably, the translation amount is calculated using the following formula:

[0025] d = k3·(B1+B2)

[0026] Where d represents the translation amount, k3 represents the third adjustment coefficient, and B1 and B2 represent the first translation amount signal and the second translation amount signal, respectively.

[0027] In another aspect of the present invention, preferably,

[0028] The control module generates a feedback term based on the tilt angle, generates a feedforward term based on the translation amount, and obtains an angle correction amount based on the feedback term and the feedforward term, including:

[0029] Feedback terms are generated based on the deviation between the target tilt angle and the current tilt angle of the fast-reflecting mirror lens;

[0030] Generate a feedforward term based on the translation amount;

[0031] Based on the feedback term and the feedforward term, a total control term is obtained, which represents the angle correction amount.

[0032] In another aspect of the present invention, preferably, the control module is based on a PID controller;

[0033] The feedback item is generated by the PID controller based on the deviation between the target tilt angle and the current fast-reflective mirror lens tilt angle;

[0034] The feedforward term is generated based on the translation amount and the feedforward gain;

[0035] The total control term is the sum of the feedback term and the feedforward term.

[0036] In another aspect of the present invention, preferably, the total control item is calculated using the following formula:

[0037] u(t)=PID(θ ref -θ)+k ff ·d

[0038] Where u(t) represents the total control term, PID represents the PID controller, and θ ref The target tilt angle is represented by θ, the tilt angle by d, and the translation amount by k. ff This represents the feedforward gain.

[0039] In another aspect of the present invention, preferably, the axis of the second sensor is parallel to the translation direction of the fast-reflecting mirror lens, the measurement point of the second sensor is the center of the fast-reflecting mirror lens, each group of second sensors is symmetrically arranged on the side of the fast-reflecting mirror lens, and the distance between the second sensor and the fast-reflecting mirror lens is greater than twice the maximum translational displacement of the fast-reflecting mirror lens.

[0040] In another aspect of the present invention, preferably, each group of first sensors is symmetrically arranged on the bottom surface of the fast-reflecting mirror lens.

[0041] (III) Beneficial Effects

[0042] The above-described technical solution of the present invention has the following beneficial technical effects:

[0043] This invention overcomes the limitations of traditional systems that rely solely on single-axis or single-probe feedback by using four symmetrically distributed first sensors and two sets of laterally positioned second sensors to acquire the tilt angle and translational information of the mirror surface. This significantly improves the accuracy and completeness of attitude sensing. The translational amount is fed forward as a disturbance prediction signal to the PID controller, and a translational compensation term is introduced into the controller output. This effectively reduces the impact of translational motion on angle control, significantly improving system response speed and reducing overshoot and steady-state error. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the overall structure of one embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of the structure of a first sensor module according to an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of the structure of the second sensor module according to an embodiment of the present invention;

[0047] Figure label:

[0048] 1: First sensor module; 110: First sensor;

[0049] 2: Second sensor module; 210: Second sensor. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0051] The accompanying drawings show structural schematic diagrams according to embodiments of the present invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0052] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0053] In the description of this invention, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0054] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0055] The invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0056] Example 1

[0057] A fast-reflecting mirror based on multi-degree-of-freedom displacement measurement, Figure 1 A schematic diagram of the overall structure of an embodiment of the present invention is shown, as follows. Figure 1 As shown, it includes: a first sensor module 1, a second sensor module 2, a fusion module, and a control module;

[0058] The first sensor module 1 and the second sensor module 2 are connected to the fusion module, and the fusion module is connected to the control module;

[0059] Figure 2 A schematic diagram of the structure of a first sensor module according to an embodiment of the present invention is shown, as follows: Figure 2 As shown, the first sensor 110 is mounted on the fast-reflecting mirror base. The first sensor module 1 includes at least two sets of first sensors 110, which are used to collect multiple tilt angle signals of the fast-reflecting mirror lens. Each set of first sensors 110 is symmetrically arranged on the bottom surface of the fast-reflecting mirror lens. Through symmetrically arranged multi-point angle measurements, the tilt attitude of the lens around two sets of vertical axes can be comprehensively reflected, achieving full-domain attitude perception. Here, the first sensor maintains a preset first distance from the fast-reflecting mirror lens.

[0060] Figure 3 This is a schematic diagram of the structure of the second sensor module according to an embodiment of the present invention, as shown below. Figure 3As shown, the second sensor module 2 includes at least two sets of second sensors 210. The second sensors 210 are used to acquire multiple translational signals of the fast-reflecting mirror lens. The axis of the second sensor 210 is parallel to the translational direction of the fast-reflecting mirror lens. The measurement point of the second sensor 210 is the center of the fast-reflecting mirror lens and is unaffected by the rotation of the mirror. Each set of second sensors is symmetrically arranged on the side of the fast-reflecting mirror lens. The distance between the second sensor and the fast-reflecting mirror lens is greater than twice the maximum translational displacement of the fast-reflecting mirror lens. The measurement axis of the second sensor 210 is strictly parallel to the translational direction of the fast-reflecting mirror lens to ensure accurate and reliable translational signals. The distance between the second sensor and the fast-reflecting mirror lens is greater than twice the maximum translational displacement of the fast-reflecting mirror lens.

[0061] The fusion module obtains the tilt angle based on multiple tilt angle signals and the translation amount based on multiple translation amount signals. The fusion module receives the real-time output signals of the first sensor module and the second sensor module, and calculates the current attitude parameters of the fast-reflecting mirror lens by combining the spatial distribution relationship between the sensors and using a weighted fusion algorithm or Kalman filtering method.

[0062] The control module generates a feedback term based on the tilt angle and a feedforward term based on the translation amount. Based on the feedback and feedforward terms, it obtains the angle correction amount. The control module adjusts the driving parameters in real time based on the attitude information provided by the fusion module to achieve closed-loop control of the lens in both tilt and translation degrees of freedom, thereby achieving fast, stable, and precise mirror motion control.

[0063] Furthermore, in this embodiment, the multiple tilt angle signals include a first tilt angle signal, a second tilt angle signal, a third tilt angle signal, and a fourth tilt angle signal; each is acquired by multiple first sensors symmetrically arranged on the bottom surface of the fast-reflecting mirror lens; the first sensors are arranged in different areas of the lens and can sense minute displacements or angle changes caused by the tilt of the lens, thereby providing multi-point angle measurement information.

[0064] The fusion module acquires the tilt angle based on multiple tilt angle signals, and processes these signals to deduce the actual tilt angle of the fast-reflecting mirror lens around two sets of orthogonal axes. This includes:

[0065] The difference between the first tilt angle signal and the second tilt angle signal is multiplied by the first adjustment coefficient to obtain the first signal difference. The difference between the first tilt angle signal and the second tilt angle signal is used as the basis for tilt change in a direction, and amplitude calibration is performed by multiplying by the first adjustment coefficient.

[0066] The difference between the third and fourth tilt angle signals is multiplied by a second adjustment coefficient to obtain the second signal difference. This difference is then used as the basis for tilt variation in another direction, and amplitude calibration is performed by multiplying it by the second adjustment coefficient.

[0067] The tilt angle is obtained based on the first signal difference and the second signal difference. The aforementioned first adjustment coefficient and second adjustment coefficient are set according to parameters such as the actual sensor deployment distance, sensitivity, and lens structure characteristics to ensure that the physical dimensions of the measurement result match the actual tilt angle.

[0068] Furthermore, based on the first signal difference and the second signal difference, the tilt angle is obtained, including calculating the tilt angle using the following formula:

[0069] θ = k1·(A1-A2) + k2·(A3-A4)

[0070] Where θ represents the tilt angle, k1 represents the first adjustment coefficient, and k2 represents the second adjustment coefficient; A1, A2, A3, and A4 represent the first tilt angle signal, the second tilt angle signal, the third tilt angle signal, and the fourth tilt angle signal, respectively. Compared to the traditional single-point sensor angle acquisition method, the multi-point differential fusion coefficient adjustment method improves the resolution and sensitivity of angle calculation; symmetrical layout effectively suppresses measurement deviations caused by environmental interference or asymmetric errors; it facilitates system calibration, and the system linearity or response range can be optimized as needed through adjustment coefficients.

[0071] Furthermore, in this embodiment, the multiple translation signals include a first translation signal and a second translation signal, and the first translation signal and the second translation signal respectively come from two sets of second sensors;

[0072] The step of obtaining the translation amount based on multiple translation amount signals includes:

[0073] The translation amount is obtained by multiplying the sum of the first and second translation signals by a third adjustment coefficient. In this embodiment, to achieve high-precision measurement of the translational motion of the fast-reflecting mirror lens, at least two sets of second sensors are set up to acquire the translational displacement signals of the lens in specific directions. Multiple translation signals, including the first and second translation signals, are acquired in real time by the second sensors respectively arranged on the sides of the lens. These sensors are arranged parallel to each other along the translational direction, and their spacing is designed to be greater than twice the maximum translational displacement of the fast-reflecting mirror lens to ensure the accuracy and stability of displacement acquisition throughout the entire stroke range and to prevent measurement blind spots.

[0074] The translation amount is calculated using the following formula:

[0075] d = k3·(B1+B2)

[0076] Where d represents the translation amount, and k3 represents the third adjustment coefficient, used for scale calibration of the sensor measurement signal to ensure consistency with the actual physical displacement. This coefficient can be set based on the sensor installation location, structural geometry, sensitivity, and system calibration results to ensure the final output translation amount has good accuracy and physical meaning. B1 and B2 represent the first and second translation signals, respectively. When the sensor is subject to local interference or has certain measurement errors, summing and averaging can effectively reduce the impact of these errors on the overall displacement measurement. High-precision displacement extraction can be achieved without complex sensor combinations or trigonometric function inversion, facilitating hardware implementation and signal processing optimization.

[0077] Furthermore, in this embodiment, the control module is based on a PID controller; the control module generates a feedback term based on the tilt angle, generates a feedforward term based on the translation amount, and obtains an angle correction amount based on the feedback term and the feedforward term, including:

[0078] Based on the deviation between the target tilt angle and the current tilt angle of the fast-reflecting mirror lens, a feedback term is generated. This feedback term is generated by the PID controller based on the deviation between the target tilt angle and the current tilt angle of the fast-reflecting mirror lens. The control module compares the target tilt angle with the actual tilt angle of the fast-reflecting mirror lens obtained by the first sensor in real time, forming a tilt angle error. The PID controller uses this error as input to calculate the feedback term, which includes a proportional term, an integral term, and a derivative term, which respectively adjust the transient response, steady-state error, and dynamic trend of the system.

[0079] Based on the translation amount, a feedforward term is generated, which is based on the translation amount and the feedforward gain. During actual operation, the translational motion of the fast-reflecting mirror lens may couple with the tilt angle, such as angular offsets caused by structural eccentricity or load disturbances. Therefore, the translation amount is introduced as the feedforward input, amplified or scaled by the feedforward gain, to calculate the feedforward term. This feedforward term has the ability to predict future system trends and can proactively compensate for displacement disturbances before they occur, improving the predictability and dynamic stability of the system response.

[0080] Based on the feedback and feedforward terms, a total control term is obtained, representing the angle correction amount. The total control term is the sum of the feedback and feedforward terms. Combining feedback control with feedforward compensation balances the system's response speed and steady-state accuracy.

[0081] Furthermore, the total control item is calculated using the following formula:

[0082] u(t)=PID(θ ref -θ)+k ff ·d

[0083] Where u(t) represents the total control term, PID represents the PID controller, and θ ref The target tilt angle is represented by θ, the tilt angle by d, and the translation amount by k. ff This represents the feedforward gain. While maintaining the steady-state accuracy advantages of traditional PID controllers, it can significantly improve dynamic response capabilities, making it particularly suitable for applications requiring high-frequency, high-acceleration operation, such as fast-reflecting mirrors. The feedforward term compensates for disturbances in advance, reducing system delay; feedback control provides steady-state correction capabilities, adapting to model uncertainties; both PID parameters and feedforward gain can be optimized through modeling or experimentation to suit different loads and structural parameters.

[0084] This invention overcomes the limitations of traditional systems that rely solely on single-axis or single-probe feedback by using four symmetrically distributed first sensors and two sets of laterally positioned second sensors to acquire the tilt angle and translational information of the mirror surface. This significantly improves the accuracy and completeness of attitude sensing. The translational amount is fed forward as a disturbance prediction signal to the PID controller, and a translational compensation term is introduced into the controller output. This effectively reduces the impact of translational motion on angle control, significantly improving system response speed and reducing overshoot and steady-state error.

[0085] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

[0086] The above description does not provide detailed explanations of the technical aspects of each layer's patterning and etching. However, those skilled in the art should understand that various methods existing in the prior art can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above.

[0087] The present invention has been described above with reference to embodiments thereof. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. The scope of the invention is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

[0088] Although embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and modifications can be made to the embodiments of the present invention without departing from the spirit and scope of the invention.

[0089] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A fast-reflecting mirror based on multi-degree-of-freedom displacement measurement, characterized in that, include: The system comprises a first sensor module (1), a second sensor module (2), a fusion module, and a control module; The first sensor module (1) and the second sensor module (2) are connected to the fusion module, and the fusion module is connected to the control module; The first sensor module (1) includes at least two sets of first sensors (110), and the first sensor module is used to collect multiple tilt angle signals of the fast-reflecting mirror lens; The second sensor module (2) includes at least two sets of second sensors (210), which are used to acquire multiple translation signals of the fast-reflecting mirror lens; The fusion module obtains the tilt angle based on multiple tilt angle signals and the translation amount based on multiple translation amount signals; The control module generates a feedback term based on the tilt angle, generates a feedforward term based on the translation amount, and obtains the angle correction amount based on the feedback term and the feedforward term.

2. The fast-reflecting mirror based on multi-degree-of-freedom displacement measurement according to claim 1, characterized in that, The plurality of tilt angle signals include a first tilt angle signal, a second tilt angle signal, a third tilt angle signal, and a fourth tilt angle signal; The fusion module obtains the tilt angle based on multiple tilt angle signals, including: The difference between the first tilt angle signal and the second tilt angle signal is multiplied by a first adjustment coefficient to obtain the first signal difference. The difference between the third tilt angle signal and the fourth tilt angle signal is multiplied by the second adjustment coefficient to obtain the second signal difference. The tilt angle is obtained based on the first signal difference and the second signal difference.

3. The fast-reflecting mirror based on multi-degree-of-freedom displacement measurement according to claim 2, characterized in that, The tilt angle is obtained based on the first signal difference and the second signal difference, including calculating the tilt angle using the following formula: θ = k1·(A1-A2) + k2·(A3-A4) Where θ represents the tilt angle, k1 represents the first adjustment coefficient, k2 represents the second adjustment coefficient, and A1, A2, A3, and A4 represent the first tilt angle signal, the second tilt angle signal, the third tilt angle signal, and the fourth tilt angle signal, respectively.

4. The fast-reflecting mirror based on multi-degree-of-freedom displacement measurement according to claim 1, characterized in that, The multiple translation signals include a first translation signal and a second translation signal, which are respectively from two sets of second sensors (210); The step of obtaining the translation amount based on multiple translation amount signals includes: The translation amount is obtained by multiplying the third adjustment coefficient by the sum of the first and second translation signals.

5. The fast-reflecting mirror based on multi-degree-of-freedom displacement measurement according to claim 4, characterized in that, The translation amount is calculated using the following formula: d = k3·(B1+B2) Where d represents the translation amount, k3 represents the third adjustment coefficient, and B1 and B2 represent the first translation amount signal and the second translation amount signal, respectively.

6. The fast-reflecting mirror based on multi-degree-of-freedom displacement measurement according to claim 1, characterized in that, The control module generates a feedback term based on the tilt angle, generates a feedforward term based on the translation amount, and obtains an angle correction amount based on the feedback term and the feedforward term, including: Feedback terms are generated based on the deviation between the target tilt angle and the current tilt angle of the fast-reflecting mirror lens; Generate a feedforward term based on the translation amount; Based on the feedback term and the feedforward term, a total control term is obtained, which represents the angle correction amount.

7. The fast-reflecting mirror based on multi-degree-of-freedom displacement measurement according to claim 6, characterized in that, The control module is based on a PID controller; The feedback item is generated by the PID controller based on the deviation between the target tilt angle and the current fast-reflective mirror lens tilt angle; The feedforward term is generated based on the translation amount and the feedforward gain; The total control term is the sum of the feedback term and the feedforward term.

8. The fast-reflecting mirror based on multi-degree-of-freedom displacement measurement according to claim 7, characterized in that, The total control item is calculated using the following formula: u(t)=PID(θ ref -θ)+k ff ·d Where u(t) represents the total control term, PID represents the PID controller, and θ ref The target tilt angle is represented by θ, the tilt angle by d, and the translation amount by k. ff This represents the feedforward gain.

9. The fast-reflecting mirror based on multi-degree-of-freedom displacement measurement according to claim 1, characterized in that, The axis of the second sensor (210) is parallel to the translation direction of the fast-reflecting mirror lens. The measurement point of the second sensor (210) is the center of the fast-reflecting mirror lens. Each group of second sensors (210) is symmetrically arranged on the side of the fast-reflecting mirror lens. The distance between the second sensor (210) and the fast-reflecting mirror lens is greater than twice the maximum translation displacement of the fast-reflecting mirror lens.

10. The fast-reflecting mirror based on multi-degree-of-freedom displacement measurement according to claim 1, characterized in that, Each group of first sensors (110) is symmetrically arranged on the bottom surface of the fast-reflecting mirror lens.

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