CN105700108A - Piezoelectric ceramic micro actuator for controlling vibration of optical mirror - Google Patents

Abstract

The invention relates to the technical field of active vibration control, and provides a piezoelectric ceramic micro-driver for optical mirror vibration control, which is used to solve the problem of high power consumption in the active control of beam pointing existing in the prior art when common actuators are used to control the optical system , Technical issues with complex structures. The piezoelectric ceramic micro-driver includes a front cover, a piezoelectric stack for controlling the position of the optical mirror in its pitch and yaw direction, and a sleeve for accommodating the piezoelectric stack. One end of the front cover abuts against the optical mirror surface, the other end is connected with one end of the piezoelectric stack and accommodated in the sleeve; the other end of the piezoelectric stack is accommodated in the sleeve with pretension. The invention provides a piezoelectric ceramic micro-driver for vibration control of an optical mirror. The micro-driver is easy to use and easy to adjust, and can directly control optical elements to realize active control of beam pointing.

Description

Piezoceramic microactuators for optical mirror vibration control

technical field

The invention relates to the technical field of active vibration control, in particular to a piezoelectric ceramic micro-driver used for optical mirror vibration control.

Background technique

With the continuous advancement of optical technology, the application fields of optical systems have been continuously expanded, and the precision requirements of optical systems have also been continuously improved. However, the application environment of the optical system is becoming more and more complex, and disturbances such as environmental vibrations have an increasing impact on the imaging of the optical system. The problem of beam pointing instability caused by environmental vibrations is common in all kinds of optical systems and has a significant impact on their performance.

However, at present, actuators are often used to achieve better imaging of optical systems in vibration environments. The role of actuators is to exert control forces on the control objects according to certain control laws. In recent years, on the basis of traditional fluid actuators, gas actuators and electrical actuators, a variety of intelligent actuators have been researched and developed, such as piezoelectric ceramic actuators, piezoelectric film actuators, Electrostrictive actuators, etc. However, these existing actuators generally have the problems of high power consumption and complex structures.

Contents of the invention

The purpose of the present invention is to provide a piezoelectric ceramic micro-driver for optical mirror vibration control, which solves the problem of high power consumption and complex structure of the active control of beam pointing that exists when the commonly used actuators are used to control the optical system in the prior art difficult technical problems.

The invention provides a piezoelectric ceramic micro-driver for optical mirror vibration control, which includes a front cover, a piezoelectric stack for controlling the position of the optical mirror in its pitch and yaw direction, and a sleeve for accommodating the piezoelectric stack , one end of the front cover abuts against the optical mirror surface, the other end is connected with one end of the piezoelectric stack and accommodated in the sleeve; the other end of the piezoelectric stack is accommodated in the sleeve in a pre-tightened manner.

Further, one end of the front cover is provided with a round end, and the round end abuts against the optical mirror surface.

Further, the other end of the front cover is provided with an inverted groove for inserting the piezoelectric stack, the inverted groove is arranged in the other end of the front cover, and chamfers are provided in the inverted groove.

Further, it also includes a linear bearing and an inner sleeve, the front cover and the piezoelectric stack are lubricated and connected through the linear bearing; the inner sleeve is sleeved on the linear bearing, and is accommodated and fixedly connected in the sleeve.

Further, it also includes a rear cover for resisting the piezoelectric stack, one end of the rear cover is inserted into the piezoelectric stack, and the other end is slidably disposed in the sleeve.

Further, the rear cover includes an upper cylinder and a lower cylinder connected, the upper cylinder is inserted into the piezoelectric stack, and the lower cylinder is slidably disposed in the sleeve.

Further, it also includes a top wire for fixing the position of the piezoelectric stack, one end of the top wire is connected to the sleeve through threads, and the other end extends out of the sleeve.

Further, the inner section of the sleeve is sequentially provided with a first fixing groove, a second sliding groove and a third abutting groove, and the inner sleeve is accommodated in the first fixing groove; the rear cover is slidably accommodated in the second sliding groove ; The top wire is threadedly connected in the third abutting groove.

Another aspect of the present invention also provides an optical mirror fine-tuning device, including an optical mirror device, at least two piezoelectric ceramic micro-drivers as described above for optical mirror vibration control, a micro-drive bracket and a mirror base body, for One end of the piezoelectric ceramic micro-driver for optical mirror vibration control is installed in the micro-driver bracket, and the other end abuts against the optical mirror surface of the optical mirror device. On two opposite sides of the lower part of the optical mirror.

Further, the optical mirror device includes a mirror base, a mirror base plate installed on the mirror base, a lens mounted on the mirror base plate, and a mirror base body installed at intervals opposite to the mirror base, and the outer lower part of the mirror base body is installed at intervals for installation. Microdrive holder for microdrives.

Technical effect of the present invention:

The invention provides a piezoelectric ceramic micro-driver for vibration control of an optical mirror. The micro-driver is easy to use and easy to adjust, and can directly control optical elements to realize active control of beam pointing.

The optical mirror surface fine-tuning device provided by the present invention is small in size, can realize accurate control of the lens with the existing control method, is smaller in size than the existing actuator, and can better meet the needs on the planet.

The above and other aspects of the present invention will be apparent with reference to the following description of various embodiments of the piezoelectric ceramic micro-actuator for optical mirror vibration control according to the present invention.

Description of drawings

Fig. 1 is the explosive decomposition schematic diagram of the preferred embodiment of the piezoelectric ceramic micro-driver used for optical mirror vibration control provided by the present invention;

Fig. 2 is the assembly schematic diagram of the preferred embodiment of the piezoelectric ceramic micro-driver that is used for optical mirror vibration control provided by the present invention;

Fig. 3 is a front view partial sectional schematic diagram of the front cover of the preferred embodiment of the present invention;

Fig. 4 is a partial cross-sectional schematic diagram of a sleeve of a preferred embodiment of the present invention;

Fig. 5 is a schematic diagram of the installation state of the preferred embodiment of the piezoelectric ceramic micro-driver for optical mirror vibration control provided by the present invention;

Fig. 6 is a partial enlarged schematic diagram of the piezoelectric ceramic micro-driver for adjusting the angle of the Z-axis or/and the X-axis in a preferred embodiment of the present invention for optical mirror vibration control;

Fig. 7 is a schematic diagram of a control effect curve in a preferred embodiment of the present invention under the condition of 10Hz excitation;

Figure 8 is a partially enlarged schematic diagram of the total displacement in Figure 7

Fig. 9 is a schematic diagram of the control effect curve in the case of 50Hz excitation in the preferred embodiment of the present invention;

Fig. 10 is a partial enlarged schematic diagram of the total displacement in Fig. 9;

Fig. 11 is a schematic diagram of the control effect curve under the condition of 150Hz excitation in the preferred embodiment of the present invention;

Fig. 12 is a partial enlarged schematic diagram of the total displacement in Fig. 11;

Fig. 13 is a schematic diagram of the control effect curve in the case of random excitation in the preferred embodiment of the present invention;

Fig. 14 is a partial enlarged schematic diagram of the total displacement in Fig. 13;

Fig. 15 is a schematic diagram of the optical path of the vibration control experiment of the optical adjustment mount used in the verification test in the preferred embodiment of the present invention.

illustration:

100, optical mirror device; 110, mirror base; 120, mirror base plate; 130, lens; 140, mirror base body; 150, micro-drive bracket; 210, front cover; , linear bearing; 230, inner sleeve; 240, piezoelectric stack; 250, back cover; 260, sleeve; 261, first fixing groove; 262, second sliding groove; 263, third abutting groove; 270, top Silk.

detailed description

The accompanying drawings constituting a part of this application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention.

1-2, the present invention provides a piezoelectric ceramic micro-driver for optical mirror vibration control, including a front cover 210, a piezoelectric stack 240 for controlling the position of the optical mirror in its pitch and yaw direction and The sleeve 260 for accommodating the piezoelectric stack 240, one end of the front cover 210 abuts against the optical mirror surface, the other end is connected with one end of the piezoelectric stack 240 and accommodated in the sleeve 260; the other end of the piezoelectric stack 240 Preloaded is contained within the sleeve 260 . The micro-driver utilizes the ability of the piezoelectric stack 240 to be driven by voltage to expand and contract, so that the optical mirror can rotate in its pitch and yaw direction, thereby realizing the adjustment of the optical mirror. The existing actuator is replaced, the size is small, and the control of the optical mirror surface can be realized by using the existing control method. The control method used here can be but not limited to such as fuzzy control method, PID control method and so on. The components that can realize these control algorithms can be provided on the device that is electrically connected to the components to be controlled. The components containing each control algorithm can be replaced with each other.

Further, it includes a front cover 210, a linear bearing 220, an inner sleeve 230, a piezoelectric stack 240 for controlling the optical mirror, a rear cover 250 for resisting the piezoelectric stack 240, and a housing for accommodating the piezoelectric stack 240. A sleeve 260 and a top wire 270 for fixing the position of the piezoelectric stack 240 . The front cover 210 is connected to the piezoelectric stack 240 through a linear bearing 220 . The inner sleeve 230 is sleeved on the outside of the linear bearing 220 and is fixedly connected with the sleeve 260 . Thus, the front end of the front cover 210 protrudes out of the sleeve 260 , and the piezoelectric stack 240 connected to the front cover 210 , the inner sleeve 230 and the linear bearing 220 are all accommodated in the sleeve 260 . The back cover 250 is accommodated in the sleeve 260 , and one end thereof abuts against the bottom surface of the piezoelectric stack 240 . One end of the top wire 270 extends into the sleeve 260 and abuts against the other surface of the back cover 250 , and the other end of the top wire 270 extends out of the sleeve 260 . The top wire 270 can be used to adjust the preload of the entire piezoelectric ceramic micro-driver used for optical mirror vibration control.

Preferably, referring to FIG. 3 , the front cover 210 includes a round end 211 and a chamfered end. The round end 211 is provided with a hemispherical head, which can effectively prevent the optical mirror from exerting shear force on the top of the front cover 210 . An inverted groove 212 is provided in the chamfered end. The piezoelectric stack 240 can be inserted into the inverted groove 212 . More preferably, the round end 211 is a hemispherical head with a radius of 4mm. The use of the round end 211 of this size can effectively reduce the excessive friction force generated when the front cover 210 contacts the mirror surface, thereby causing wear on the mirror surface. At the same time, it can also achieve precise control and avoid excessive movement during the control process.

Preferably, the inverted groove 212 is an inverted groove 212 with a depth of 8 mm and a diameter of 5 mm, and chamfers are provided at the ports to improve the connection tightness with the piezoelectric stack 240 .

More preferably, the front cover 210 is a cylindrical structure with a length of 37 mm and a diameter of 8 mm, and is made of stainless steel. At this point the stiffness can meet the requirements.

The linear bearing 220 used can be a common linear bearing 220, preferably with an outer diameter of 15mm, an inner diameter of 8mm, and a length of 17mm. Using a linear bearing 220 of this size can effectively realize the expansion and contraction of the piezoelectric stack 240, making it and the front cover 210 in a lubricated Under the circumstances, push the front cover 210 to guide the movement.

The inner sleeve 230 is a cylindrical structure, more preferably, a cylindrical structure with a length of 17 mm, an outer diameter of 22 mm and an inner diameter of 15 mm. Used to fix the linear bearing 220 on the inner wall of the sleeve 260 . Thus, it is helpful to realize the lubricating and guiding function of the linear bearing 220 . More preferably, it is made of stainless steel.

The piezoelectric stack 240 may be a commercially available product. For example, it may be P-843.60, a product of Puai Nanometer Displacement Technology (Shanghai) Co., Ltd. (PI). Under the action of the driving voltage, the piezoelectric stack 240 can realize the elongation or shortening of the predetermined length in combination with common algorithm control, so as to realize the precise control of the optical mirror surface to be adjusted.

Preferably, the rear cover 250 includes two stacked coaxial cylinders. The diameter of these two cylinders increases from top to bottom. With this structure, the pressing effect on the piezoelectric stack 240 can be effectively realized. More preferably, the lower cylinder of the rear cover 250 has a length of 15 mm and a diameter of 16 mm. The upper cylinder is 6mm long and 8mm in diameter. The lower cylinder is provided with an inverted groove 212 with a length of 1.5 mm and a depth of 1 mm near the upper cylinder, and the upper cylinder is fixed with the piezoelectric stack 240 by threads. Using the rear cover 250 of this mechanism can minimize the overall size of the micro-driver while maintaining the required rigidity.

Preferably, referring to Fig. 4, the inner section of the sleeve 260 is provided with a first fixing groove 261, a second sliding groove 262 and a third abutment groove 263 in sequence, and the first fixing groove 261 is used for installing the inner sleeve 230, in order to realize alignment For the fixing of the inner sleeve 230 , the diameter of the first fixing groove 261 is close to the inner sleeve 230 . The second sliding groove 262 is used to accommodate the piezoelectric stack 240 and the rear cover 250 , and the rear cover 250 can slide in the second sliding groove 262 as the piezoelectric stack 240 expands and contracts. The third abutting groove 263 is used for accommodating the top wire 270 . Preferably, the lower cylinder can slide in the second receiving groove in the sleeve 260 . Since the diameter of the second receiving groove is different from that of the third abutting groove 263 , the movement of the rear cover 250 can be restricted. Preferably, in order to reduce the overall size, wire installation grooves are opened on the inner wall of the sleeve 260 to arrange the wires that energize the piezoelectric stack 240 . Specifically, wires such as driving voltage signal wires may be provided.

Preferably, one end of the jacking wire 270 extends into the third abutting groove 263 and is threadedly connected thereto, so that the jacking wire 270 can be pushed against the rear cover 250 . The other end of the jacking wire 270 protrudes out of the sleeve 260 for easy operation and adjustment of the jacking wire 270 . It is used to adjust the pretension degree of the piezoelectric stack 240 to realize fast and accurate correction.

5-6, another aspect of the present invention also provides an optical mirror fine-tuning device, an optical mirror device 100, at least two piezoelectric ceramic micro-drivers as described above for optical mirror vibration control, a micro-driver bracket 150 and Mirror base body 140, one end of the piezoelectric ceramic micro-driver used for optical mirror vibration control is installed in the micro-drive bracket 150, and the other end is abutted on the optical mirror surface of optical mirror device 100, and two are used for optical mirror vibration control. The piezoelectric ceramic micro-drivers are respectively abutted on two opposite sides of the lower part of the optical mirror. The control and adjustment of the position of the mirror 130 in the pitch and yaw directions can be realized by arranging at least two aforementioned micro-actuators respectively on two opposite sides of the lower part of the mirror 130 .

The optical mirror device 100 can be various commonly used optical mirror devices 100 . Preferably, the optical mirror device 100 includes a mirror base 110 , a mirror base plate 120 mounted on the mirror base 110 , a lens 130 mounted on the mirror base plate 120 , and a mirror base body 140 mounted opposite to the mirror base 110 at intervals. One side of the mirror base body 140 is provided with a micro-actuator bracket 150 for installing a piezoelectric ceramic micro-actuator for optical mirror vibration control. One end of the piezoelectric ceramic micro-driver used for optical mirror vibration control is installed in the micro-driver bracket 150 , and the other end passes through the mirror base body 140 and abuts on the mirror base plate 120 . The device can be used to adjust the angle of the mirror seat plate 120 in the pitch direction (such as rotating around the X axis) and the yaw direction (such as rotating around the Z axis).

During use, the piezoelectric ceramic micro-actuator provided by the present invention is installed on the rear side of the mirror base body 140, and its front cover 210 is supported on the mirror base plate 120, and the depth and thickness of the insertion degree are adjusted. Adjust the degree of support of the micro-driver to the mirror seat plate 120, namely, as shown in FIG. After coarse adjustment, tighten the top wire 270 to fix the initial position of the micro-driver provided by the present invention, and then turn the rear end of the top wire 270 to realize fine adjustment of the preload of the piezoelectric stack 240 . All kinds of electric wires required by the piezoelectric stack 240 are connected to the piezoelectric stack 240 , and the driving voltage is input to control the expansion and contraction of the piezoelectric stack 240 to realize the attitude adjustment of the mirror base plate 120 in the pitch direction and yaw direction.

The following control experiments prove that the piezoelectric ceramic micro-actuator provided by the present invention for optical mirror vibration control has better control accuracy. The comparative experiment is the control result obtained by similar control under the same conditions without using the driver provided by the present invention.

At the three frequency points of 10Hz, 50Hz, and 150Hz simple harmonic excitation with the same amplitude, the base platform of the optical adjustment frame provided by the micro-driver provided by the present invention is installed to vibrate, and the laser beam emitted by the laser emitter is excited. After the galvanometer surface is reflected, a laser spot is formed on the screen of the optically sensitive detector. The micro-driver provided by the present invention controls the offset of the laser spot on the screen of the optically sensitive detector by controlling the pitch and yaw attitude of the mirror seat plate 120. Realize laser beam pointing control.

The experimentally obtained control effect curves of the offset of the light spot on the optical sensitive detector after being reflected by the excited mirror are shown in Figures 7-14, and the control effect curves under random excitation are shown in Figures 13-14. The ordinates in FIGS. 7 to 14 are the offset of the laser spot on the photosensitive sensor screen, and the unit is mm.

It can be seen from Figures 7 to 14 that the offset of the laser spot after vibration control basically does not exceed 0.05mm. The optical path diagram of the vibration control experiment of the optical adjustment frame is shown in Figure 15, in which the optical sensitive detector screen is perpendicular to the laser target pointing direction, and the distance between the center of the screen and the optical center of the excited mirror is L=10m, and the beam deflection can be obtained by calculation The relationship between the angle θ and the total offset a of the laser spot on the optically sensitive detector screen is shown in the following formula:

$\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; a</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}$

It can be obtained from the above formula that the piezoelectric ceramic micro-driver provided by the present invention can control the light beam pointing stability under the vibration environment of the lens system to the micro-arc level (read the ordinate, then explain the reflected light path, and finally Converted into an angle to obtain the micro-rad scale), it is verified that the micro-driver provided by the present invention can effectively realize control. The comparison is the displacement before and after the control. After the piezoelectric ceramic micro-driver provided by the present invention is used for control, the total displacement of the controlled object is suddenly reduced to no more than 0.05mm, which proves that the device provided by the present invention has an obvious effect.

The invention has simple structure, flexible and convenient control, and is suitable for vibration control of various optical elements and active control of beam pointing.

It will be clear to a person skilled in the art that the scope of the present invention is not limited to the examples discussed above, but that several changes and modifications are possible without departing from the scope of the invention as defined in the appended claims. While the invention has been illustrated and described in detail in the drawings and description, such illustration and description are illustrative or exemplary only and not restrictive. The invention is not limited to the disclosed embodiments.

Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the invention, from a study of the drawings, the specification and the claims. In the claims, the term "comprising" does not exclude other steps or elements, while the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims shall not be construed as limiting the scope of the invention.

Claims (10)

1. A piezoelectric ceramic micro-driver for optical mirror vibration control is characterized in that it includes a front cover, a piezoelectric stack for controlling the position of the optical mirror in its pitching and yaw direction, and a piezoelectric stack for accommodating the piezoelectric ceramic. The sleeve of the electric stack, one end of the front cover abuts against the optical mirror surface, the other end is connected with one end of the piezoelectric stack and accommodated in the sleeve; the other end of the piezoelectric stack Preloaded within the sleeve. 2. The piezoelectric ceramic micro-driver for optical mirror surface vibration control according to claim 1, characterized in that, one end of the front cover is provided with a round end, and the round end abuts against the optical mirror surface superior. 3. The piezoelectric ceramic micro-driver for optical mirror vibration control according to claim 2, characterized in that, the other end of the front cover is provided with an inverted groove for inserting the piezoelectric stack, the An inverted groove is arranged in the other end of the front cover, and chamfers are provided in the inverted groove. 4. The piezoelectric ceramic micro-driver for optical mirror vibration control according to claim 3, further comprising a linear bearing and an inner sleeve, and the front cover and the piezoelectric stack are lubricated and connected by a linear bearing; The inner sleeve is sleeved on the linear bearing, and accommodated and fixedly connected in the sleeve. 5. The piezoelectric ceramic micro-driver for optical mirror vibration control according to claim 4, further comprising a rear cover for resisting the piezoelectric stack, a section of the rear cover is inserted into the In the piezoelectric stack, the other end is slidably disposed in the sleeve. 6. The piezoelectric ceramic micro-driver for optical mirror vibration control according to claim 5, characterized in that, the back cover includes a connected upper cylinder and a lower cylinder, and the upper cylinder is inserted into the In the piezoelectric stack, the lower cylinder is slidably disposed in the sleeve. 7. The piezoelectric ceramic micro-driver for optical mirror vibration control according to claim 6, further comprising a top wire for fixing the position of the piezoelectric stack, one end of the top wire is threaded and The sleeves are connected, and the other end extends out of the sleeves. 8. The piezoelectric ceramic micro-actuator for optical mirror vibration control according to claim 7, characterized in that, the inner section of the sleeve is sequentially provided with a first fixing groove, a second sliding groove and a third resisting groove. The top groove, the inner sleeve is accommodated and clamped in the first fixing groove; The rear cover is slidably accommodated in the second sliding groove; The jacking wire is screwed into the third abutting groove. 9. An optical mirror fine-tuning device, characterized in that it comprises an optical mirror device, at least two piezoelectric ceramic micro-drivers and micro-drive brackets for optical mirror vibration control according to any one of claims 1 to 8 And the mirror base body, one end of the piezoelectric ceramic micro-driver used for optical mirror vibration control is installed in the micro-drive bracket, and the other end abuts against the optical mirror surface of the optical mirror device, the optical The piezoelectric ceramic micro-actuators controlled by the vibration of the mirror surface are arranged in pairs and abut against two opposite sides of the lower part of the optical mirror surface respectively. 10. The optical mirror fine-tuning device according to claim 9, characterized in that, the optical mirror device comprises a mirror base, a mirror base plate mounted on the mirror base, a lens mounted on the mirror base plate, and a The mirror base body is installed at intervals, the outer lower part of the mirror base body is installed at intervals with a micro-driver bracket for installing the micro-driver.