CN113917642B - A series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform - Google Patents

Abstract

The invention discloses a series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform, which solves the problems that the traditional optical element adjustment platform cannot simultaneously take into account the multi-degree-of-freedom precision adjustment, and the adjustment platform itself has low complexity and high reliability. , the platform includes a support base, a first-level adjustment mechanism and a second-level adjustment mechanism; the optical element can be driven to translate along the Z direction and rotate around the X and Y directions through the first micro-nano-level driving component in the first-level adjustment mechanism. The second micro-nano-level driving component in the secondary adjustment mechanism can drive the optical element to translate along the X and Y directions, so as to realize the multi-dimensional and high-precision adjustment of the spatial position of the optical element in the optical system, thereby improving the performance index of the optical system.

Description

A series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform

technical field

The invention relates to an adjustment platform for optical elements, in particular to a series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform.

Background technique

The photoelectric measurement system/equipment is an important support in the fields of national defense, scientific exploration, and social and people's livelihood, and the optical system is the eye of the photoelectric measurement device, and its performance indicators determine the efficiency of the photoelectric measurement system/equipment. In essence, the optical system controls and redistributes light energy through the precise layout of different forms of optical components. The realization of its performance indicators depends on the high-precision (um, nm) spatial arrangement of the optical components.

The complexity and motorization of non-cooperative space targets require a relatively larger field of view and higher line-of-sight (LOS) stabilization accuracy of the optical system; air-to-ground target search requires a more efficient large-scale push-broom; public transportation records Surveillance requires high-resolution imaging and detection of more targets. The realization of the above-mentioned optical-related performance indicators such as larger field of view, higher scanning efficiency, and higher resolution is achieved by precise control of the spatial position of optical components.

The continuous progress of science and technology has put forward increasingly high performance index requirements for optical systems, and traditional optical component adjustment platforms have been unable to meet the current requirements for precise adjustment of optical components.

Traditional fast mirrors can usually only adjust two-dimensional rotational degrees of freedom, and cannot do anything for the need for focusing action (usually along the optical axis translation direction);

The typical scanning mechanism can only achieve two-dimensional translation in the plane, and cannot adjust the amount of rotation;

The mature commercial Stewart six-degree-of-freedom adjustment table can realize multi-degree-of-freedom adjustment, but due to its highly coupled dynamic model, it leads to singular characteristics such as dead point and instability, which requires complex and precise kinematics solutions. Higher requirements are put forward, and the system complexity is higher.

SUMMARY OF THE INVENTION

In order to solve the problems that the traditional optical element adjustment platform cannot take into account the precise adjustment of multiple degrees of freedom at the same time, as well as the low complexity and high reliability of the adjustment platform itself, the present invention provides a series-parallel coupled multi-degree-of-freedom optical element precise adjustment platform. .

The basic realization principle of the present invention is:

The micro-nano linear motor is selected as the driving element, and the compliant unit is used as the supporting and guiding mechanism of the load to realize the multi-dimensional and high-precision adjustment of the optical element.

The technical scheme adopted by the present invention to solve its technical problems is:

A series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform is characterized by comprising a support base, a primary adjustment mechanism and a secondary adjustment mechanism;

The support base is used to install the adjusted optical element;

The first-level adjustment mechanism includes a first-level frame and a first micro-nano-level driving component;

The first-level frame includes an upper-layer guide piece, a support column and a lower-layer base plate; the upper-layer guide piece and the lower-layer base plate are arranged in parallel, and the upper-layer guide piece and the lower-layer base plate are connected by three support columns; a support seat is installed on the upper-layer guide piece;

There are at least three first micro-nano-level driving components, and they are evenly installed on the lower bottom plate of the primary frame, and the flexible driving ends of the at least three first micro-nano level driving components are connected to the support seat through the upper guide plate ;

The secondary adjustment mechanism includes a second micro-nano-level driving component, a flexible guide rod and a base;

There are two second micro-nano-level driving components, and both are fixedly installed on the base, and the driving ends of the second micro-nano-level driving components are all connected to the lower bottom plate,

There are at least three flexible guide rods and they are evenly distributed; one end of the flexible guide rod is fixedly connected with the base, and the other end is fixedly connected with the side ear of the support column after passing through the lower bottom plate;

Under the driving of at least three first micro-nano-level driving components, under the constraint of the upper guide plate, and under the guiding action of the flexible guide rod, the support seat has the degrees of freedom of rotation around the X and Y axes and translation along the Z direction;

Under the driving of the two second micro-nano-level driving components and the action of the flexible guide rod, the support base has the freedom of translation along the X and Y axes.

Further, the above-mentioned upper-layer guide piece adopts the integrated processing and molding of slow-moving wire, and the rigidity of the upper-layer guide piece in six directions needs to meet the following conditions:

Among them, k _x1 , k _y1 , k _z1 represent the translation stiffness of the upper guide piece along the X, Y, Z directions, respectively; k _Rx1 , k _Ry1 , k _Rz1 represent the upper guide piece around the X, Y, Z directions, respectively the rotational stiffness;

Further, the thickness of the upper guide sheet is less than 1.5mm.

Further, the above-mentioned first micro-nano-level driving assembly includes a first micro-nano-level linear motor and a flexible rod; the lower end of the flexible rod is connected with the displacement output end of the first micro-nano-level linear motor, and the upper end of the flexible rod passes through the upper guide plate after the Connect to the support base.

Further, the above-mentioned flexible rod includes a top, a deforming part and a fixing part arranged in sequence from top to bottom; the top is used for connecting with the support base, and the deforming part is used for providing the displacement amount of Z-direction translation, and around the The rotation amount of X and Y axis rotation, and the fixed part is used to connect with the displacement output end of the micro-nano linear motor.

Further, the conditions that the length L ₁ and diameter φd ₁ of the above-mentioned deformed portion need to meet are:

Further, the above-mentioned flexible guide rod includes a guide section, a deformation section and a fixed section arranged in sequence from top to bottom; the guide section is fixedly connected with the side ears of the support column, and the deformation section is used to provide X and Y directions. The amount of translation displacement, the fixed segment is used to be fixedly connected with the base.

Further, the conditions that the length L ₂ and the diameter φd ₂ of the above-mentioned deformed section need to meet are:

Further, the above-mentioned second micro-nano-level driving component is a second micro-nano-level linear motor.

Further, the above-mentioned support base is a triangular structure provided with hollow weight-reducing holes, and the optical element to be adjusted is fixed by means of gluing.

The beneficial effects of the present invention are:

1. The present invention is based on the upper guide plate and flexible rod of the primary adjustment mechanism, and the flexible guide rod of the secondary adjustment mechanism, combined with the micro-nano linear motor to form a series-parallel adjustment platform with a flexible configuration. Bearings, guide rails, hinges and other structural forms, the deformation is mainly based on the elastic deformation of the weak links of the structural parts, which completely eliminates friction and sticking during movement, and at the same time, it is maintenance-free and can be used in vacuum, high and low temperature and other environments. In use, there is no special lubrication requirement, and interference and contamination of the optical system are completely avoided.

2. The primary adjustment mechanism and the secondary adjustment mechanism adopted in the present invention basically realize a frictionless configuration, have high motion resolution, and can realize high-frequency, high-precision, and high-resolution motion adjustment within the elastic deformation range.

3. Compared with the classic Stewart platform, the present invention uses a two-stage adjustment structure in the form of series and parallel, which greatly simplifies its modeling and drive control, and is especially suitable for occasions with a high degree of customization of indicators.

4. The adjusting platform of the present invention has few parts and components, simple and compact structure, adopts integrated processing and manufacture, has no light blocking effect, is easy to assemble and debug, and can be flexibly customized for the interface with the optical element.

5. The micro-nano linear motor of the present invention is used as the driving source, which can achieve nano-level adjustment accuracy within the millimeter-level adjustment range. Compared with traditional adjustment methods such as lead screws with gaps, the accuracy is significantly improved.

Description of drawings

FIG. 1 is a schematic structural diagram of the present invention.

FIG. 2 is a cross-sectional view of FIG. 1 .

FIG. 3 is an assembly perspective view when the optical element is not mounted.

Figure 4 is a structural diagram of the primary frame.

5 is a schematic top view of a first-level adjustment structure;

6 is a schematic top view of a secondary adjustment structure;

Figure 7 is a schematic diagram of a flexible rod.

Figure 8 is a schematic diagram of a flexible guide rod.

The reference numbers are as follows:

1-optical element, 2-support base, 3-first-level adjustment mechanism, 4-secondary adjustment mechanism, 5-level-1 frame, 6-first micro-nano-level drive assembly, 7-upper guide plate, 8-support column, 9-lower bottom plate, 10-first micro-nano linear motor, 11-flexible rod, 111-top, 112-deformation part, 113-fixed part, 12-second micro-nano-level drive assembly, 13-flexible guide rod, 131-guide segment, 132-deformation segment, 133-fixed segment, 14-base.

Detailed ways

In order to make the above objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Example. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Many specific details are set forth in the following description to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can do so without departing from the connotation of the present invention. Similar promotion, therefore, the present invention is not limited by the specific embodiments disclosed below.

At the same time, in the description of the present invention, it should be noted that the orientation or positional relationship indicated in terms such as "upper, lower, inner and outer" is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention. The invention and simplified description do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first, second or third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

Unless otherwise expressly specified and limited in the present invention, the term "installation, connection, connection" should be understood in a broad sense, for example: it may be a fixed connection, a detachable connection or an integral connection; it may also be a mechanical connection, an electrical connection or a direct connection. The connection can also be indirectly connected through an intermediate medium, or it can be the internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

The series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform provided by the present invention is divided into a series-connected primary adjustment mechanism and a secondary adjustment mechanism, and the optical element can be driven by the first micro-nano-level driving component in the primary adjustment mechanism Translate along the Z direction, and rotate around the X and Y directions. The second micro-nano-level driving component in the secondary adjustment mechanism can drive the optical element to translate along the X and Y directions, so as to realize the optical element space in the optical system. Position multi-dimensional high-precision adjustment, thereby improving the performance index of the optical system.

It should be noted that: in this embodiment, the Z direction is the optical axis direction of the optical element, and the X and Y directions are the two directions perpendicular to the optical axis direction;

As shown in Figures 1-3, the specific structure of a series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform is: including a support base 2, a primary adjustment mechanism 3 and a secondary adjustment mechanism 4;

The support base 2 is used to install the adjusted optical element 1, and together with the optical element 1 constitute the adjustment object of the precision adjustment platform. The triangular structure with hollow weight-reducing holes is used as a lightweight design, and the adjusted optical element and the support base use a ring. Oxygen glue is reliably fixed and ensures the accuracy of the optical surface.

The first-level adjustment mechanism 3 includes a first-level frame 5 and a first micro-nano-level drive assembly 6;

As shown in FIG. 4 , the primary frame 5 includes an upper guide piece 7 , a support column 8 and a lower floor 9 ; the upper guide piece 7 is arranged in parallel with the lower floor 9 , and there are three supports between the upper guide piece 7 and the lower floor 9 The column 8 is connected; the support seat 2 is installed on the upper guide plate 7;

In this embodiment, the upper layer guide piece 7 is formed by integrated processing of slow-moving wires. Generally, the thickness of the upper layer guide piece 7 is less than 1.5mm, and its rigidity in 6 degrees of freedom needs to meet the following conditions:

Among them, k _x1 , k _y1 , k _z1 represent the translation stiffness of the upper guide piece along the X, Y, Z directions, respectively; k _Rx1 , k _Ry1 , k _Rz1 represent the upper guide piece around the X, Y, Z directions, respectively the rotational stiffness;

There are three first micro-nano-level driving components 6, and they are evenly installed on the lower bottom plate 9 of the primary frame. Seat 2 connection;

Specifically, as shown in FIG. 7 , the first micro-nano-level driving assembly 6 includes a first micro-nano-level linear motor 10 and a flexible rod 11 ; the flexible rod 11 includes a top 111 , a deformation portion 112 and a The fixed part 113; the top part 111 is used for connecting with the support base 2; The displacement output end of the stage linear motor 10 is connected, and the conditions that the length L ₁ and the diameter φd ₁ of the deformed portion 112 of the flexible rod 11 must meet are:

Since the flexible guide rod has greater flexibility in bending around the X-axis and Y-axis, and has greater rigidity along the Z-direction tension and compression, combined with the stiffness characteristics of the upper guide sheet 3, its release around the X, Y-axis and the Z-axis release Translation degrees of freedom.

The secondary adjustment mechanism 4 includes a second micro-nano-level drive assembly 12 , a flexible guide rod 13 and a base 14 ;

There are two second micro-nano-level driving components 12 , and they are both fixedly installed on the base 14 , and the driving ends of the second micro-nano level driving components 12 are all connected to the lower base plate 9 ; The stage driving component 12 is a second micro-nano linear motor;

Specifically, as shown in FIG. 8 , there are three flexible guide rods 13 , which are evenly distributed; the flexible guide rods 13 include a guide section 131 , a deformation section 132 and a fixed section 133 arranged in sequence from top to bottom; The side ears 81 of the support column 8 are fixedly connected, the deformation section 132 is used to provide translation displacement in the X and Y directions, the fixed section 133 is used to be fixed with the base 14, and the deformation section 132 of the flexible guide rod has a length L ₂ and a diameter The conditions to be satisfied by φd ₂ are:

The flexural section coefficient and tensile and compressive stiffness EA of the flexible guide rod can be described as:

Due to the large bending flexibility of the flexible guide rod in the X and Y directions, it releases the translational degrees of freedom in the X and Y directions and constrains the remaining degrees of freedom.

Based on the above description of the overall structure of the adjustment platform and its various components, the adjustment process of the adjustment platform is now introduced:

Assembly process

First, the support base 2 is fixedly connected to the corresponding position of the upper guide sheet 7, and the three flexible rods 11 are respectively connected with the three first micro-nano linear motors 10 to form three first micro-nano driving assemblies 6, and the three A first micro-nano-level driving assembly 6 is installed on the lower bottom plate 9, and corresponds to the position of the three connection points on the support base 2. Connect, and finally use epoxy glue to fasten the optical element 1 to the support base 2;

Then install the two second micro-nano linear motors 12 on the base 14, as shown in the right side of FIG. Correspondingly, finally, the three flexible guide rods 13 are fixedly connected to the side ears 81 of the support column 8 to form a multi-degree-of-freedom precision adjustment platform coupled in series and parallel.

Use process

The process of the first-level adjustment agency is as follows:

The coordinated driving of the first micro-nano linear motors 10 evenly distributed on the three circumferences can realize the adjustment of the three degrees of freedom of the optical element 1 through the combined deformation of the upper guide sheet 7 and the flexible rod 11 . The process is as follows: referring to FIG. 1 and FIG. 5 , two first micro-nano-level linear motors 10 (A motor and B motor in the figure) are driven in the same direction and equal value, and another first micro-nano-level linear motor 10 (in the figure) C motor) reverse drive, which can realize the rotation around the X axis; or two first micro-nano linear motors 0 (A motor and C motor in the figure) are driven in reverse and equivalently, and the other first micro-nano linear motor The motor 10 (the B motor in the figure) does not participate in the movement, and can realize the rotation around the Y axis; the three first micro-nano linear motors 10 are driven in the same direction and equivalently, and can realize the translation along the Z axis;

The process of the secondary adjustment agency is as follows:

Through the driving of the second micro-nano linear motor, combined with the deformation of the flexible guide rod 13, the two-degree-of-freedom movement of the secondary adjustment mechanism 4 is realized. Driven, the first-level adjustment mechanism 3, the support base 2 and the optical element 1 can all be adjusted in translation along the X direction. Driven by another second micro-nano linear motor, the first-level adjustment mechanism 3, the support base 2 can be realized. and the translation adjustment of optical element 1 along the Y direction;

It can be seen from the above that the first and second-stage adjustment mechanisms of the present invention both belong to parallel coupling adjustment within this stage, and belong to series connection between the two-stage adjustment mechanisms. The coupling motion within the stage can be precisely controlled by the decoupling algorithm, and the series connection between the stages has a one-to-one decoupling relationship, which is simple and easy to control. The integrated adjustment stage coupled in series and parallel, on the premise of ensuring accurate adjustment of multiple degrees of freedom, requires a more concise control system.

Claims (10)

1. A series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform is characterized in that: comprising a support base, a first-level adjustment mechanism and a second-level adjustment mechanism; The support base is used to install the adjusted optical element; The first-level adjustment mechanism includes a first-level frame and a first micro-nano-level driving component; The first-level frame includes an upper-layer guide piece, a support column and a lower-layer base plate; the upper-layer guide piece and the lower-layer base plate are arranged in parallel, and the upper-layer guide piece and the lower-layer base plate are connected by three support columns; a support seat is installed on the upper-layer guide piece; There are at least three first micro-nano-level driving components, and they are evenly installed on the lower bottom plate of the primary frame, and the flexible driving ends of the at least three first micro-nano level driving components are connected to the support seat through the upper guide plate ; The secondary adjustment mechanism includes a second micro-nano-level driving component, a flexible guide rod and a base; There are two second micro-nano-level driving components, and both are fixedly installed on the base, and the driving ends of the second micro-nano-level driving components are all connected to the lower bottom plate, There are at least three flexible guide rods and they are evenly distributed; one end of the flexible guide rod is fixedly connected with the base, and the other end is fixedly connected with the side ear of the support column after passing through the lower bottom plate; Under the driving of at least three first micro-nano-level driving components, under the constraint of the upper guide plate, and under the guiding action of the flexible guide rod, the support seat has the degrees of freedom of rotation around the X and Y axes and translation along the Z direction; Under the driving of the two second micro-nano-level driving components and the action of the flexible guide rod, the support base has the freedom of translation along the X and Y axes. 2. The multi-degree-of-freedom optical element precision adjustment platform for series-parallel coupling according to claim 1, wherein the upper guide piece is integrally processed and formed by slow-moving wires, and the rigidity of the upper guide piece in six directions is required. The following conditions:

Among them, k _x1 , k _y1 , k _z1 represent the translation stiffness of the upper guide piece along the X, Y, Z directions, respectively; k _Rx1 , k _Ry1 , k _Rz1 represent the upper guide piece around the X, Y, Z directions, respectively rotational stiffness. 3 . The series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform according to claim 1 or 2 , wherein the thickness of the upper guide plate is less than 1.5 mm. 4 . 4. The multi-degree-of-freedom optical element precision adjustment platform coupled in series and parallel according to claim 3, characterized in that: the first micro-nano-level driving component comprises a first micro-nano-level linear motor and a flexible rod; The lower end is connected with the displacement output end of the first micro-nano linear motor, and the upper end of the flexible rod is connected with the support seat after passing through the upper guide piece. 5 . The multi-degree-of-freedom optical element precision adjustment platform for series-parallel coupling according to claim 4 , wherein the flexible rod comprises a top, a deformation part and a fixing part arranged in sequence from top to bottom; In connection with the support base, the deformation portion is used to provide the displacement amount of Z-direction translation and the rotation amount of rotation around the X and Y axes, and the fixed portion is used to connect with the displacement output end of the micro-nano linear motor. 6. The multi-degree-of-freedom optical element precision adjustment platform for series-parallel coupling according to claim 5, characterized in that: the conditions that the length L ₁ and the diameter φd ₁ of the deformed portion need to satisfy are:

7 . The multi-degree-of-freedom optical element precision adjustment platform coupled in series and parallel according to claim 1 , wherein the flexible guide rod comprises a guide section, a deformation section and a fixed section arranged in sequence from top to bottom; the The guide section is fixedly connected with the side ears of the support column, the deformation section is used for providing translational displacement in the X and Y directions, and the fixed section is used for fixed connection with the base. 8. The multi-degree-of-freedom optical element precision adjustment platform for series-parallel coupling according to claim 7, wherein the conditions that the length L ₂ and the diameter φ d ₂ of the deformed section need to meet are:

9 . The series-parallel coupled multi-degree-of-freedom optical element precision adjustment platform according to claim 1 , wherein the second micro-nano-level driving component is a second micro-nano-level linear motor. 10 . 10. The multi-degree-of-freedom optical element precision adjustment platform for series-parallel coupling according to claim 1, wherein the support base is a triangular structure provided with hollow weight-reducing holes, which are fixed and adjusted by means of gluing Optical element.

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