A flexible design based visual axis vibration reduction stable platform

Abstract

The application discloses a line-of-sight vibration reduction stable platform based on flexible design, which comprises a gimbal, a flexible connection array, a damper array, a central bearing assembly and a support disc assembly; the gimbal comprises an outer pitching frame and an inner frame, the inner frame is arranged inside the outer pitching frame and coaxial with the outer pitching frame; the support disc assembly has two groups, which are arranged between the side walls of the outer pitching frame and the inner frame respectively; the central bearing assembly has two groups, which are connected with the outer pitching frame, the support disc assembly and the inner frame respectively; the flexible connection array is divided into two groups, an outer group and an inner group, the outer group is connected with the outer pitching frame and the support disc assembly, and the inner group is connected with the inner frame and the support disc assembly; the damper array has two groups, which are connected with the two outer walls of the inner frame and the opposite support disc assembly respectively. The application saves internal space, simplifies the system and enhances reliability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of airborne optoelectronic technology, and relates to a line-of-sight vibration reduction stable platform based on flexible design, which is used for isolating an effective load from translation, rotation and angular vibration of a support structure. BACKGROUND

[0002] An airborne optoelectronic stable platform is an important task equipment integrating visible light television, infrared thermal imaging and laser measuring illuminator and other optoelectronic precision sensors, and realizes accurate movement of the optoelectronic stable platform through servo software control, so as to realize functions such as "searching, detecting and positioning" of the carrier aircraft, and has the advantages of small size, light weight and high precision. Due to the influence of the working environment of the carrier aircraft, vibration phenomenon of the platform is inevitable, and the vibration reduction system is the only vibration reduction and buffering device in the optoelectronic stable platform, which is used for reducing the influence of the vibration or impact of the carrier aircraft platform on the performance of the optoelectronic sensor, especially the stable precision.

[0003] In the existing technology, the mainstream structure form of the optoelectronic stable platform is composed of two inner and outer gimbals, each gimbal has two rotation axes of azimuth and elevation, the azimuth and elevation structures of the outer gimbal are followed by the system, and the azimuth and elevation structures of the inner gimbal are core components, the overall rigidity is high, and the final image stabilization effect can be realized. The rotation shafts of the gimbals are driven by electromagnetic torque motors, and the torque motors need to be installed at the axial positions of the gimbals, so that the left and right spaces for installing the effective load are limited. The stable platform needs to avoid interference between the vibration reduction device or the gimbal, and the problem brought by the above structure is that when the stable platform tracks the target movement beyond the control limit, the self-locking phenomenon of the gimbal will be caused. In addition, the traditional two-axis four-frame structure form has only two degrees of freedom of stabilization function of elevation and azimuth, while the new type of flexible stable platform can realize multi-degree-of-freedom (including roll direction) stabilization function. SUMMARY

[0004] (I) Invention purpose

[0005] The purpose of the present application is to provide a line-of-sight vibration reduction stable platform suitable for the field of airborne optoelectronic technology, to connect the traditional outer elevation frame and the inner frame by using a flexible connection array, to realize multi-degree-of-freedom rotation of the effective load including azimuth, elevation and roll direction through the combination of the flexible connection array and the damper array, and to isolate the effective load from translation, rotation and angular movement of the support structure, so as to solve the interference problem between the stable platform and the vibration reduction device or the gimbal, and the self-locking phenomenon of the gimbal when over-the-top tracking.

[0006] (II) Technical scheme

[0007] In order to solve the above technical problems, the application provides a boresight vibration reduction stable platform, which comprises a gimbal, a flexible connection array 3, a damper array 4, a central bearing assembly 5 and a support disc assembly 7; the gimbal comprises an outer tilt frame 1 and an inner frame 2, the inner frame 2 is arranged inside the outer tilt frame 1 and coaxial with the outer tilt frame 1; the support disc assembly 7 has two groups, which are arranged between the side walls of the outer tilt frame 1 and the inner frame 2 respectively; the central bearing assembly 5 has two groups, which are connected with the outer tilt frame 1, the support disc assembly 7 and the inner frame 2 respectively; the flexible connection array 3 is divided into two groups, an outer group and an inner group, the outer group is connected with the outer tilt frame 1 and the support disc assembly 7, and the inner group is connected with the inner frame 2 and the support disc assembly 7; the damper array 4 has two groups, which are connected with the two outer walls of the inner frame 2 and the opposite support disc assembly 7 respectively.

[0008] (Three) beneficial effects

[0009] The boresight vibration reduction stable platform based on the flexible design has the following beneficial effects:

[0010] (1) The combination of the flexible connection structure and the damper array can not only provide the multi-degree-of-freedom rotation of the azimuth, the tilt and the roll of the payload relative to the frame, but also complete the passive vibration isolation of the high-frequency disturbance without adding the isolation structure. The stable platform in this form does not need to avoid the interference between the traditional damper and the gimbal, which has the advantages of saving the internal space, simplifying the system and enhancing the reliability.

[0011] (2) The flexible connection structure is composed of eight pairs of flexible connection structure monomers, and the vibration reduction array layout structure after the arrangement of the eight pairs of flexible connection structure monomers is in a circular shape. Each pair of flexible connection structure monomers is arranged in a conical shape. This arrangement can make the elastic support point center coincide with the mass center of the payload, ensure the linear-angular vibration decoupling, avoid causing large angular disturbance, make the trimming more simple and accurate, and thus more easily obtain good imaging effect.

[0012] (3) The use of more than three electromagnetic torque motors instead of the single-degree-of-freedom torque motor can avoid the installation of these torque motors on the axis of the gimbal, release the layout limitation of the motor and reduce the use space of the load, and when the stable platform tracks the target, the movement in the azimuth direction beyond the control limit will not cause the self-locking phenomenon of the gimbal, which creates convenience for the automatic tracking and identification of the target. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is the front view of the boresight vibration reduction stable platform.

[0014] Figure 2 is the sectional view of the boresight vibration reduction stable platform.

[0015] Figure 3is the schematic diagram of explosion of the boresight vibration reduction stable platform.

[0016] Figure 4 is the sectional view of the flexible spring.

[0017] Figure 5 is the schematic diagram of circular layout of the flexible connection array of the boresight vibration reduction stable platform.

[0018] Figure 6 is the schematic diagram of damper array of the boresight vibration reduction stable platform. DETAILED DESCRIPTION

[0019] In order to make the objects, contents and advantages of the present application more clear, the specific embodiments of the present application are described in further detail below in combination with the drawings and examples.

[0020] The embodiment is suitable for the boresight vibration reduction stable platform in the field of airborne photoelectric technology, which connects the traditional outer pitch frame and inner frame by the flexible connection array, and realizes the multi-degree-of-freedom rotation of the payload, including the azimuth, pitch and roll directions, through the combination of the flexible connection array and damper array. Meanwhile, the payload is isolated from the translation, rotation and angular motion of the support structure, which solves the interference problem between the stable platform and the vibration reduction device or gimbals, and the self-locking phenomenon of the gimbals during the over-the-top tracking.

[0021] As shown in Figures 1 to 6 , the boresight vibration reduction stable platform comprises gimbals, a flexible connection array 3, a damper array 4, a center bearing assembly 5 and a support disc assembly 7; the gimbals comprise an outer pitch frame 1 and an inner frame 2, the inner frame 2 is arranged inside the outer pitch frame 1 and coaxial with the outer pitch frame 1; the support disc assembly 7 has two groups, which are arranged between the side walls of the outer pitch frame 1 and the inner frame 2 respectively; the center bearing assembly 5 has two groups, which are connected with the outer pitch frame 1, the support disc assembly 7 and the inner frame 2 respectively; the flexible connection array 3 is divided into two groups, an outer group and an inner group, the outer group is connected with the outer pitch frame 1 and the support disc assembly 7, and the inner group is connected with the inner frame 2 and the support disc assembly 7; the damper array 4 has two groups, which are connected with the two outer walls of the inner frame 2 and the opposite support disc assembly 7 respectively.

[0022] Each group of support disc assembly 7 comprises a laminated support disc one 7a and a support disc two 7b, the support disc one 7a is coaxial with the support disc two 7b and connected by mounting screws, the support disc one 7a is close to the inner frame 2 and used for supporting the inner frame 2, and the support disc two 7b is close to the outer pitch frame 1 and used for supporting the outer pitch frame 1. The outer side wall of the support disc two 7b is provided with a support flange plate, and the support flange plate is in contact with the inner wall of the outer pitch frame 1.

[0023] Each center bearing assembly 5 includes a center bearing one 5a and a center bearing two 5b, the center bearing one 5a is connected with the inner frame 2 through the center through hole of the inner frame 2, and the other end is connected with the center of the center bearing two 5b through the center through hole of the support disc two 7b and the center member 6, and the center bearing two 5b is installed in the center through hole of the outer pitch frame 1. The center bearing one 5a and the center bearing two 5b are connected in clearance fit, the center bearing one 5a rotates with the inner frame 2, and the center bearing two 5b rotates with the outer pitch frame 1. The center member 6 is installed on the center through hole of the support disc one 7a.

[0024] The flexible connection array 3 is arranged between the outer pitch frame 1 and the inner frame 2 of the optoelectronic stable platform, and is used for realizing the multi-degree-of-freedom stability function of the optoelectronic stable platform; the outer pitch frame 1 is a first mounting member, can be angularly adjusted about a pitch axis relative to a member, and can be angularly adjusted about an azimuth axis. The inner frame 2 is used for mounting a sensor assembly, and a torque motor can be mounted on the inner frame 2, each torque motor has a movable axis, can apply a positioning force to the inner frame 2, and forms a main / passive damping function with the flexible connection structure.

[0025] In the flexible connection array 3, one end of the outer group is connected with the outer pitch frame 1 through a hinge, and the other end is connected with the support disc two 7b through a hinge; one end of the inner group is connected with the inner frame 2 through a hinge, and the other end is connected with the support disc one 7a through a hinge.

[0026] In the flexible connection array 3, the outer group and the inner group form sixteen pairs of flexible connection structure monomers, and eight pairs of flexible connection structure monomers are arranged between the two side inner walls of the outer pitch frame 1 and the two side outer walls of the inner frame 2. The eight pairs of flexible connection structure monomers on the same side are arranged to form a circular flexible connection array 3, each pair of flexible connection structure monomers includes two or more flexible springs arranged in a conical shape or at an angle of 120°. In each pair of flexible connection structure monomers, one end of the spring is connected with the corresponding inner side wall of the outer pitch frame 1 or the outer side wall of the inner frame 2, and the other end is connected with the corresponding support disc assembly 7; each flexible connection structure monomer enables the inner frame 2 to perform linear translation in three degrees of freedom and rotation in three degrees of freedom relative to the outer pitch frame 1 in the pitch, azimuth and roll directions.

[0027] The two springs of each pair of flexible connection structure monomers include a flexible spring body 3-2 and a rotating end cover 3-1 connected at both ends thereof; the flexible spring body 3-2 has a spherical hinge structure at both ends, and the rotating end cover 3-1 is connected with the spherical hinge structure at one end and has a hook structure at the other end connected with the mounting hole of the corresponding inner side wall of the outer pitch frame 1, the mounting hole of the corresponding outer side wall of the inner frame 2 and the support disc assembly 7, so as to ensure that the characteristics of the flexible spring body 3-2 remain unchanged when the outer pitch frame 1 rotates about the pitch axis.

[0028] The inner frame 2 is provided with a motor array, and the flexible connection array 3 is driven by the motor array to realize rotation. The motor array comprises a plurality of torque motors, each torque motor has a movement direction along which the flexible connection array 3 can be freely moved. In this way, the motor array comprising a plurality of torque motors can freely rotate around any rotation axis.

[0029] The spring is a mechanical processed double-end spiral flexible spring, and the two ends are connected with the rotary end cover in the form of spherical hinge. Due to the rigidity of the inner frame 2 and the flexible connection array 3 itself, each spring will have a plurality of orders of inherent modal in the longitudinal and transverse directions, and the vibration amplification factor of the system with high-rigidity flexible spring at the resonance frequency will be large, which will cause fatigue damage of the flexible spring. Therefore, the amplification factor at the resonance is reduced by adding friction to the flexible spring, and the specific implementation is to add a sleeve with a diameter slightly larger than the inner diameter of the spring in the flexible spring. The radial pressure of the spring inner diameter is increased through interference fit, thereby increasing the service life of the spring.

[0030] The damper array 4 is connected with the support disc 1 7a at one end through a hinge link and connected with the inner frame 2 at the other end through a screw. Each group of damper array 4 comprises at least six dampers, which can be hydraulic or pneumatic. One end of the damper is connected with the support disc 1 7a through a spherical hinge structure, and the other end is connected with the inner frame 2 through a mounting screw. The motor array drives the flexible connection array 3 to freely move, so that the damper can rotate around the three orthogonal axes of X, Y and X without bending deformation of the damper.

[0031] In operation, the combination of the flexible connection array 3 and the damper array 4 can replace the passive vibration isolation function of the high-frequency disturbance of the vibration isolation mechanism in the two-axis four-frame structure, and provide a stable working environment for the line-of-sight platform. Further, a motor array can be arranged on the inner frame 2 to drive a kind of active / passive hybrid vibration isolation system, which comprises an array of at least four support motors. Each torque motor has a movement direction along which the flexible connection structure can be freely moved. In this way, the motor array comprising a plurality of torque motors can freely rotate around any rotation axis, realizing low-frequency disturbance suppression and active motion control of the effective load.

[0032] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present application. These improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A flexible design based visual axis vibration reduction stabilizing platform, characterized in that, The application relates to a gimbal mechanism, which comprises an outer tilt frame (1), an inner frame (2), a damping array (4), a center bearing assembly (5) and a support disc assembly (7); the inner frame (2) is arranged inside the outer tilt frame (1) and coaxial with the outer tilt frame (1); the support disc assembly (7) has two groups, which are arranged between the side walls of the outer tilt frame (1) and the inner frame (2) respectively; the center bearing assembly (5) has two groups, which are connected with the outer tilt frame (1), the support disc assembly (7) and the inner frame (2) respectively; the flexible connection array (3) is divided into two groups, an outer group and an inner group; the outer group is connected with the outer tilt frame (1) and the support disc assembly (7), and the inner group is connected with the inner frame (2) and the support disc assembly (7); the damping array (4) has two groups, which are connected with the two outer walls of the inner frame (2) and the opposite support disc assembly (7) respectively. Each group of the support disc assembly (7) comprises a support disc one (7a) and a support disc two (7b) which are coaxial and connected by mounting screws; the support disc one (7a) is close to the inner frame (2) and used for supporting the inner frame (2), and the support disc two (7b) is close to the outer tilt frame (1) and used for supporting the outer tilt frame (1); The outer side wall of the support disc two (7b) is provided with a support flange plate which is in contact with the inner wall of the outer tilt frame (1); Each group of the center bearing assembly (5) comprises a center bearing one (5a) and a center bearing two (5b); one end of the center bearing one (5a) is connected with the inner frame (2) through the center through hole of the inner frame (2), and the other end is connected with the center of the center bearing two (5b) through the center through hole of the support disc two (7b) and the center component (6), and the center bearing two (5b) is arranged in the center through hole of the outer tilt frame (1); the center component (6) is arranged on the center through hole of the support disc one (7a); The center bearing one (5a) and the center bearing two (5b) are connected in a clearance fit mode; the center bearing one (5a) rotates along with the inner frame (2), and the center bearing two (5b) rotates along with the outer tilt frame (1); In the flexible connection array (3), one end of the outer group is connected with the outer tilt frame (1) through a hinge, and the other end is connected with the support disc two (7b) through a hinge; one end of the inner group is connected with the inner frame (2) through a hinge, and the other end is connected with the support disc one (7a) through a hinge. ​ The flexible connection array (3) is formed by sixteen pairs of flexible connection structure monomers, eight pairs of which are arranged between the inner walls of the outer tilt frame (1) and the outer walls of the inner frame (2); the eight pairs of flexible connection structure monomers on the same side form a circular flexible connection array (3), each pair of flexible connection structure monomers includes two or more flexible springs arranged in a conical shape; in each pair of flexible connection structure monomers, one end of the spring is connected to the inner side wall of the corresponding outer tilt frame (1) or the outer side wall of the inner frame (2), and the other end is connected to the corresponding support disc assembly (7); each flexible connection structure monomer enables the inner frame (2) to perform linear translation in three degrees of freedom and rotation in three degrees of freedom relative to the outer tilt frame (1) in the pitch, azimuth and roll directions; Each pair of flexible connection structure monomers includes two springs, each including a flexible spring body (3-2) and a rotating end cover (3-1) connected to both ends of the flexible spring body (3-2); the two ends of the flexible spring body (3-2) are ball hinge structures, one end of the rotating end cover (3-1) is connected to the ball hinge structure, and the other end of the hook structure is connected to the mounting hole of the inner side wall of the corresponding outer tilt frame (1), the mounting hole of the outer side wall of the inner frame (2), and the support disc assembly (7); The inner frame (2) is provided with a motor array, and the flexible connection array (3) is driven by the motor array to rotate; the motor array includes a plurality of torque motors, each torque motor has a movement direction, and the flexible connection array (3) is moved freely along the movement direction; The damper array (4) is connected to the support disc one (7a) through a hinge link at one end and connected to the inner frame (2) through a screw at the other end; each group of damper array (4) includes at least six dampers, one end of the damper is connected to the support disc one (7a) through a ball hinge structure, and the other end is connected to the inner frame (2) through a mounting screw.

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