JP2007155091A - Double gimbal mechanism with triaxial dynamic damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double gimbal mechanism with a triaxial dynamic damper, wherein the vibration control performance and stability of a pay-load part is improved by absorbing vibration applied to an outside gimbal as much as possible. <P>SOLUTION: A dynamic damper module 10 has a module frame 27 arranged in a EL support mounting frame 26. An EL rotation mechanism 3 is stored in an center space 27a of the module frame 27, and the triaxial dynamic damper is arranged therearound. The triaxial dynamic damper consists of a dynamic damping weight 28 as an auxiliary mass vibrative in triaxial directions, a plate spring 29 vibrative in a Y-axial direction, a hinge spring 32 vibrative in 360° directions including X-axial and Z-axial directions, a damping material 31 connecting the dynamic damping weight 28 to the module frame 27, and a damping material 33 connecting the module frame 27 to the EL support mounting frame 26. The dynamic damper module 10 is mounted concentrically with the EL axis of a supporting portion 6b of an EL supporting frame member 6 rotatably supporting an EL shell. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention stabilizes the visual axis and controls the vibration of the EL shell in all directions as much as possible by controlling the orientation of the imaging device in an imaging system mounted on a moving body such as an aircraft, ship, or vehicle in two directions. The present invention relates to a double gimbal mechanism with a three-axis dynamic vibration absorber that stabilizes the posture by absorbing it.

  In general, cameras and other equipment in imaging systems mounted on moving bodies such as aircraft, ships, and vehicles are subjected to vibration-proof support for cameras and other equipment because various vibrations originating from the moving body are applied through the mounting base. Therefore, it is necessary to stabilize the space with high accuracy.

  As a method of supporting mechanism to achieve such high-accuracy space stabilization, a dual structure gimbal (support rotation) that can easily change the visual axis of the camera etc. in all directions (from the center of the sphere to all radiation directions) Stand device).

Usually, the double gimbal is composed of an outer gimbal and an inner gimbal supported by a payload portion built in the outer gimbal.
The inner gimbal is a device that finely moves a device such as a camera mounted on the payload portion in the XYZ three-axis directions together with the circuit portion. That is, it is a support unit that shares the stabilization of the camera image space and prevents camera shake.

  The outer gimbal is a support unit that shares the directivity control in all directions of the camera visual axis. When changing the viewing axis direction of a camera or the like, the payload portion that supports the inner gimbal on which the camera is directly mounted can be turned in various directions by the outer gimbal.

  That is, the payload portion can be turned in all directions including an AZ (azimuth) direction and an EL (elevation) direction. Therefore, vibrations, shocks, and other accelerations caused by changing the viewing axis direction of the camera or the like are applied to the payload portion in all directions.

  In this case, there is a stabilization mechanism that supports the internal equipment to prevent vibrations and the internal camera and other devices collide with the inner frame that supports the reaction unit and damage the camera and peripheral devices. Various considerations have been made.

As such a stabilization mechanism, a long-focus camera is held by a two-axis gimbal capable of rotating around the AZ axis and rotating around the EL axis perpendicular to the AZ axis, and a mounting portion to the movable body An isotropic anti-vibration mechanism is known as a structure that obtains high-precision stabilization of the camera visual axis against disturbances such as vibration, impact, and inertial load received from the camera. (For example, refer to Patent Document 1.)
JP-A-2004-232688 (see paragraphs [0018] to [0030], FIGS. 2, 3, and 4)

  By the way, the vibration isolating mechanism of the above-mentioned Patent Document 1 is based on the vibration isolating element strut using the spring element and the dash pot using the cylinder and the piston, thereby isolating and stabilizing the payload portion in the EL shell, that is, the inner gimbal. I am trying.

  However, in this anti-vibration mechanism, adjustment of the vibration transmission characteristic is left to the spring damper element alone, and the amplitude damping ratio of the vibration applied to the outer gimbal to the inner gimbal is determined by the spring constant of the internal anti-vibration element strut.

  Therefore, in order to increase the vibration damping effect, it is necessary to reduce the spring constant of the anti-vibration element strut, that is, to design the natural frequency of the built-in anti-vibration module as low as about several Hz.

  However, the outer diameter of the outer gimbal cannot be easily increased due to restrictions on the operation of the platform on which the outer gimbal is mounted. Therefore, there is a limit to the amount of movement of the inner gimbal in the EL shell of the outer gimbal up and down, front, rear, left and right.

  In other words, there is a limit to the size of the vibration isolation mechanism disposed in the EL shell, and thus, the spring constant of the vibration isolation element strut reaches a limit to be reduced to a certain extent. As described above, it is difficult to greatly improve the vibration proofing property of the photographing device or the like in the inner gimbal because of its design specifications.

Then, it is necessary to reduce the vibration itself that enters the vibration isolation mechanism by another method. That is, a mechanism for damping the natural vibration of the outer gimbal itself is required.
The technique of the above-mentioned Patent Document 1 is intended to prevent vibration of a photographing device or the like in the inner gimbal in the EL shell, and does not consider the vibration isolation of the outer gimbal itself on the mounting base portion.

  According to actual measurements, in the outer gimbal of the double gimbal, the effective value of vibration generated on the AZ axis of the mounting base portion of the moving body is 10 times the effective vibration value of the EL axis that is the EL shell support portion of the outer gimbal. It has been found that

  Therefore, if the effective vibration value at the EL axis with respect to the mounting base portion can be further reduced, it is considered that the vibration isolation and stability of the payload portion in the EL shell can be further enhanced.

  In view of the above-described conventional situation, the object of the present invention is to provide a double with a three-axis vibration absorber that absorbs as much as possible the vibration applied to the outer gimbal from the mounting base to improve the vibration isolation and stability of the payload. It is to provide a gimbal mechanism.

  The double gimbal mechanism with a three-axis dynamic vibration absorber of the present invention includes an outer gimbal that can rotate in any direction with two axes of AZ (azimuth) and EL (elevation) with respect to the mounting base, and an EL shell of the outer gimbal. A payload portion supported, an inner gimbal having a triaxial support portion that is supported by the payload portion and directs the visual axis of the imaging device in an arbitrary direction, and a vibration isolation mechanism for the payload portion provided in the EL shell A three-axis dynamic vibration absorber that suppresses resonance of the outer gimbal with respect to the mounting base in an EL support portion that rotatably supports the EL shell on the EL shaft. It has a module.

  In this double gimbal mechanism with a three-axis vibration absorber, for example, the three-axis vibration absorber module has an EL support portion mounting structure comprising a disk portion and an annular portion standing perpendicular to the edge of the disk portion. And a module frame disposed in the EL support part mounting frame in a shape along the inner diameter of the EL support part mounting frame, the module frame having a center part for accommodating the EL shell rotating device, And a peripheral portion in which a triaxial vibration absorber is disposed. The triaxial vibration absorber absorbs vibration in at least the X-axis direction and the Z-axis direction and absorbs vibration in the Y-axis direction. Plate springs, a dynamic vibration absorbing weight that absorbs vibration in the G direction, a damping material provided between the support frame and the member, and another damping material provided between the support frame and the other support frame. Configured.

  According to the present invention, a three-axis dynamic vibration absorber module that attenuates vibration disturbance from the mounting environment including the resonance of the outer gimbal is installed in the dual structure gimbal, so that the vibration applied to the outer gimbal is absorbed as much as possible. It is possible to provide a double gimbal mechanism with a three-axis dynamic vibration absorber that can increase the amplitude attenuation rate against the input vibration to the outer gimbal and thereby improve the vibration isolation and stability of the payload. It becomes.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 (a) is a schematic front view showing the internal structure of a camera directing device having a dual structure gimbal mechanism, with the front cover and rear cover removed, and FIG. It is the side view which attached the cover.

As shown in FIGS. 2A and 2B, the camera directing apparatus 1 includes an outer gimbal 4 having a biaxial rotating mechanism including an AZ rotating mechanism 2 and an EL rotating mechanism 3.
The outer gimbal 4 includes an EL support frame member 6 that is rotatably attached to the attachment base 5 of the moving body via the AZ rotation mechanism 2 as shown by an arrow a in the figure, and an EL support frame member 6 that has an EL. As shown by an arrow b in the figure, an EL assembly 8 is rotatably supported via an EL rotating shaft 7 of the rotating mechanism 3.

  The AZ rotation mechanism 2 includes a motor, an angle sensor, and the like inside, and an upper portion 6a of the EL support frame member 6 is attached to the rotation output side. From the upper part 6a of the EL support frame member 6, support parts 6b extending downward at right angles from two opposite sides are formed, and the above-described EL rotation mechanism 3 is provided in each support part 6b.

The EL rotation mechanism 3 also includes a motor, an angle sensor, and the like, and the EL assembly 8 is attached to the rotation output side so as to be rotatable around the EL rotation shaft 7.
Further, although described in detail later, the EL rotation mechanism 3 is integrated into the dynamic vibration absorber module 10 including the three-axis dynamic vibration absorber according to the present invention and is disposed concentrically.

  The EL assembly 8 has an outer shell of an EL shell formed by an EL shell center cover 11, an EL shell front cover 12, and an EL shell rear cover 13, and the EL shell center cover 11 includes the EL rotation mechanism 3. It is supported by the support portion 6 b of the EL support frame member 6 through the dynamic vibration absorber module 10.

  Inside the EL assembly 8, the anti-vibration modules 14 (14a, 14b) are arranged above and below in the frame axis direction concentric with the AZ rotating shaft 2a. The upper and lower two anti-vibration modules 14 each have an outer plate 15 (15a, 15b) and an inner plate 16 (16a, 16b). The outer plate 15 is bolted to the inner upper and lower sides of the EL shell center cover 11, and the EL The position is fixed in the shell.

  Between the outer plate 15 and the inner plate 16, six struts 17 with springs that can be expanded and contracted within a certain range are arranged along the circumference of the plate. Two spring-loaded struts 17 form a V-shape, and each spring-loaded strut 17 has one end engaged with the inner plate 16 by a spherical joint and the other end locked to the outer plate 15 by a spherical joint. .

  Further, between the outer plate 15 and the inner plate 16, three air dampers 18 are arranged at equal intervals on the inner side of the arrangement position of the spring-equipped struts 17. Each air damper 18 has one end in the longitudinal direction engaged with the inner plate 16 by a spherical joint, and the other end engaged with the outer plate 15 by a spherical joint.

  The vibration of the anti-vibration module 14, that is, the force that the anti-vibration module 14 receives from the outside is elastically buffered by the spring-loaded strut 17 and further absorbed by the air damper 18.

  That is, the anti-vibration module 14 exhibits an anti-vibration function with six degrees of freedom by six struts 17 with springs and three air dampers 18 sandwiched between two plates (outer plate 15 and inner plate 16). To do.

  A payload portion 19 is disposed between the inner plates 16 (16a, 16b) of these two vibration isolation modules 14. The main part of the reaction unit 19 includes a support column 21, a spherical bearing 22, and a payload frame 23.

  The struts 21 of the payload portion 19 are fixed by attaching their upper and lower ends to the inner plate 16 (16a, 16b) of the vibration isolation module 14. Thereby, the position of the entire payload portion 19 is fixed so as to be sandwiched between the image stabilization module 14a and the image stabilization module 14b.

  In addition, the payload frame 23 of the payload portion 19 is held by the support column 21 via the spherical bearing 22. Although not particularly illustrated, the payload frame is rotatably held on the support column 21 by an inner shaft composed of a triaxial actuator that advances and retreats in three directions XYZ.

  For example, a camera 24 is mounted on one side of the payload frame 23, and a wiring unit 25 including, for example, a circuit board is mounted together on the other side. The camera 24 is, for example, a visible camera or an IR camera (infrared night vision camera).

The orientation of the visual axis of the camera 24 can be stabilized by controlling the posture of the payload frame 23 by the inner shaft.
Accordingly, the payload portion 19 (or the payload frame 23) forms an internal gimbal with respect to the camera 24.

  As described above, the outer gimbal 4 exhibits the above-described six-degree-of-freedom anti-vibration function by the anti-vibration modules 14 (14a and 14b) provided above and below the EL shell. The outer gimbal 4 is further provided with a dynamic vibration absorbing function with respect to the vibration external pressure received from the mounting base 5 by the dynamic vibration absorber module 10 shown in FIG.

Hereinafter, the dynamic vibration absorber module 10 of the present invention provided on the outer gimbal 4 and exhibiting the dynamic vibration absorption function will be described.
FIG. 2 is a cross-sectional view showing an example of the dynamic vibration absorber module 10 provided in the outer gimbal 4. 1 shows the dynamic vibration absorber module 10 shown on the left side of FIG. 1 (a). However, the dynamic vibration absorber module 10 is connected to the outer gimbal 4 as shown in FIG. 1 (a). Are arranged symmetrically with respect to the AZ rotation shaft 2a.

FIG. 3A is a front view of a leaf spring disposed in the dynamic vibration absorber module 10, and FIG. 3B is a front view of a dynamic vibration absorber weight similarly disposed in the dynamic vibration absorber module 10. is there.
The leaf spring 29 shown in the dynamic vibration absorber module 10 of FIG. 2 shows a cross-sectional view taken along the line AA ′ in FIG. 3A, and the dynamic vibration damping weight 28 shown in FIG. The BB 'cross-sectional arrow figure in is shown.

  The portion where the dynamic vibration absorber module 10 shown in FIG. 2 is attached to the outer gimbal 4 responds at the lowest order of the outer gimbal 10 regardless of the direction of the EL assembly 8 (hereinafter simply referred to as EL shell). This is the part where the peak of magnification appears.

By installing the dynamic vibration absorber module 10 in this part, the maximum amplitude magnification reduction effect can be obtained.
As shown in FIGS. 2 and 3A and 3B, the dynamic vibration absorber module 10 has a module frame 27 disposed in an EL support mounting frame 26. In the central space 27a of the module frame 27, the EL rotation mechanism 3 shown in FIG.

  The triaxial dynamic vibration absorber of the present invention is disposed around the central space 27 a of the module frame 27. The triaxial dynamic vibration absorber includes a dynamic vibration weight 28, a leaf spring 29, a damping material 31, and a hinge spring 32.

The dynamic vibration absorbing weight 28 is used as an auxiliary mass for the outer gimbal 4. As the material, for example, a donut-shaped member made of a relatively heavy metal or the like is used.
As shown in FIG. 3B, the dynamic vibration absorber weight 28 is formed with four bolt screw holes 34 at intervals of 90 degrees. Further, on the back surface, there is provided an attenuation material engaging portion which is engaged with one end of the attenuation material 31 although it is not visible in the figure.

  The plate spring 29 is made of a rigid elastic member. As shown in FIG. 3 (a), four bolt insertion holes 35 are formed at intervals of 90 degrees outward from the circumference. Four other bolt insertion holes 36 are formed at intervals of 90 degrees (in the middle and between bolt insertion holes 35 and 35).

  The bolt 37 shown in FIG. 2 is inserted into the bolt insertion hole 36 of the leaf spring 29 and is screwed into the bolt screw hole 34 of the dynamic vibration absorbing weight 28 to be fixed, whereby the leaf spring 29 and the dynamic vibration absorbing weight 28 are connected. Connected.

  2 is inserted into the bolt insertion hole 35 of the leaf spring 29 and the bolt insertion hole (not shown) of the module frame 27, and is screwed and fixed to one end of the hinge spring 32.

  Thus, the dynamic vibration absorbing weight 28 is connected to the module frame 27 via the bolt 37, the leaf spring 29, and the bolt 38 in the Z-axis direction, and connected to the module frame 27 via the damping material 31 in the Y-axis direction. It will be in the state.

  The hinge spring 32 has both end portions 32a formed thick and the center portion 32b formed thin. The hinge spring 32 is interposed between the peripheral end surface of the module frame 27 and the peripheral end surface of the EL support mounting frame 26 with the axial direction parallel to the Y-axis direction.

  As described above, the bolt 38 is inserted into the bolt insertion hole 35 of the leaf spring 29 and the bolt insertion hole (not shown) of the module frame 27, and is screwed and fixed to one end of the hinge spring 32. Thus, the module frame 27 is connected to the EL support mounting frame 26 in the Y-axis direction via the hinge spring 32.

  Further, the module frame 27 is coupled to the EL support mounting frame 26 in the Z-axis direction via a damping material 33 interposed between the outer peripheral surface of the module frame 27 and the inner peripheral surface of the EL support mounting frame 26. As the damping materials 31 and 33, for example, silicon gel or the like is used.

The EL support attachment frame 26 is finally attached to the support portion 6 a of the EL support frame member 6 by a bolt screw 39 protruding from the other end of the hinge spring 32.
The hinge spring 32 can absorb and vibrate flexibly in all directions perpendicular to the EL axis (360-degree direction including the X-axis and Z-axis) with the thin central portion 32b as the center. The leaf spring 29 is capable of absorbing vibration in the EL axis direction (Y axis direction).

  As a result, the dynamic vibration absorbing weight 28 absorbs vibrations in all three axial directions. The dynamic vibration absorbing weight 28 as the auxiliary mass uses the auxiliary mass supported by the support portion 6b of the EL support frame member 6 as a reaction force and causes a relative displacement between the EL support frame member 6 of the outer gimbal 4 and the EL. The vibration energy of resonance with respect to the mounting base 5 of the support frame member 6 is absorbed.

That is, the dynamic vibration absorber module 10 is in the form of a three-axis dynamic vibration absorber module that absorbs vibrations in all three axial directions.
The spring constant value of the leaf spring 29, the damping coefficient of the damping material 31 or 33, and the spring constant of the hinge spring 32 are optimized, for example, as shown in the optimum tuning condition shown in Equation 50 and the optimum damping as shown in Equation 51. By doing so, it is possible to effectively reduce the vibration transmission magnification to the payload portion 19 from the input vibration to the outer gimbal 4.

FIG. 4 is a diagram showing the effect of the three-axis dynamic vibration absorber module of the present invention. In the figure, the horizontal axis indicates the frequency (Hz) on a logarithmic scale, and the vertical axis indicates the transmission magnification (times) on a logarithmic scale.
For comparison, the vibration transmission magnification without the dynamic vibration absorber is indicated by a solid line, and the vibration transmission magnification with the dynamic vibration absorber is indicated by a broken line in FIG.

  In the example shown in the figure, the vibration transmission magnification with no dynamic vibration absorber is 10 times, and the vibration transmission magnification with a dynamic vibration absorber is 3.3 times. That is, in the case of the presence of the dynamic vibration absorber, the vibration transmission magnification is reduced to 1/3 than in the case of the absence of the dynamic vibration absorber.

  Thus, according to the double gimbal mechanism with a three-axis dynamic vibration absorber module of the present invention, in addition to the spatial stabilization of the conventional double structure gimbal with a built-in vibration isolation mechanism, further spatial stabilization can be achieved. .

In addition to the above reduction in vibration transmission magnification, although not particularly shown, M.M. S. It has also been found that the (effective value) acceleration is reduced from 6.1 Grms to 4.0 Grms.
FIG. 5 is a cross-sectional view showing another example of the dynamic vibration damper module as described above. In the figure, the same components as in FIG. 2 are given the same reference numerals as in FIG.

  As shown in FIG. 5, in this dynamic vibration absorber module 40, a round bar bending spring 41 is used instead of the hinge spring 32 shown in FIG. The round bar bending spring 41 shown in FIG. 5 has a thick connecting portion 42 with the module frame 27 and a thin connecting portion 53 with the EL support mounting frame 26.

  Even if comprised in this way, the function equivalent to the case of FIG. 2 can be given. In addition, the round bar bending spring 41 may be formed so that the connecting portion 42 with the module frame 27 is narrow and the connecting portion 53 with the EL support mounting frame 26 is thick, contrary to FIG.

  As described above, in the present invention, in the dual structure gimbal, the three-axis vibration absorber module that attenuates the vibration disturbance from the mounting environment including the resonance of the outer gimbal is used to reduce the amplitude magnification of the center of gravity of the entire apparatus. Because it is installed in an effective place, it can absorb the vibration applied to the outer gimbal as much as possible and increase the amplitude attenuation rate with respect to the input vibration to the outer gimbal. It is possible to provide a double gimbal mechanism with a three-axis dynamic vibration absorber that improves stability.

(a) is a schematic front view showing the camera directing device having a double structure gimbal mechanism with the front cover and the rear cover removed, and (b) is a side view with the two covers attached. . It is sectional drawing which shows an example of the dynamic vibration damper module with which an outer side gimbal is equipped. (a) is a plan view of a leaf spring provided in the dynamic vibration absorber module, and (b) is a plan view of a dynamic vibration absorber weight provided in the dynamic vibration absorber module. It is a figure which shows the effect by the triaxial dynamic vibration damper module of this invention. It is sectional drawing which shows the other example of the dynamic vibration damper module with which an outer side gimbal is equipped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera directivity apparatus 2 AZ rotating mechanism 2a AZ rotating shaft 3 EL rotating mechanism 4 Outer gimbal 5 Mounting base 6 EL support frame member 6a Upper part 6b Supporting part 7 EL rotating shaft 8 EL assembly 10 Dynamic vibration absorption module 11 EL shell center cover 12 EL shell front cover 13 EL shell rear cover 14 (14a, 14b) Anti-vibration module 15 (15a, 15b) Outer plate 16 (16a, 16b) Inner plate 17 Strut with spring 18 Air damper 19 Reaction part 21 Post 22 Spherical bearing 23 Payload frame 24 Camera 25 Wiring part 26 EL support mounting frame 27 Module frame 27a Central space 28 Dynamic vibration weight 29 Leaf spring 31 Damping material 32 Hinge spring 32a Both ends 32b Central part 33 Damping material 34 Bolt screw Hole 35, 36 Bolt insertion hole 37, 38 Bolt 39 Bolt screw 40 Dynamic vibration absorption module 41 Round bar bending spring 42, 43 Connecting portion

Claims (2)

An outer gimbal that can rotate in any direction with two axes of AZ (azimuth) and EL (elevation) with respect to the mounting base, a reaction unit supported in the EL shell of the outer gimbal, and an imaging device supported by the reaction unit In a double gimbal mechanism having a payload portion having a triaxial support portion that directs the visual axis of the optical axis in an arbitrary direction, and a vibration isolation mechanism and a posture stabilization mechanism of the reaction portion provided in the EL shell,
With a three-axis vibration absorber, the EL support portion that rotatably supports the EL shell on the EL shaft has a three-axis vibration absorber module that suppresses resonance of the outer gimbal with respect to the mounting base. Double gimbal mechanism. The three-axis dynamic vibration absorber module includes an EL support portion mounting frame including a disc portion and an annular portion standing perpendicularly from an edge of the disc portion, and a shape along the inner diameter of the EL support portion mounting frame. And a module frame disposed in the EL support part mounting frame.
The module frame has a central part that houses the EL shell rotating device, and a peripheral part in which a triaxial vibration absorber is arranged,
The three-axis vibration absorber includes a bending spring that absorbs vibration in at least the X-axis direction and the Z-axis direction, a leaf spring that absorbs vibration in the Y-axis direction, a dynamic vibration absorber weight that absorbs vibration in the G direction, and a support 2. A double with a three-axis vibration absorber according to claim 1, further comprising: a damping material provided between the frame and the member; and another damping material provided between the support frame and another support frame. Gimbal mechanism.