A two-axis four-frame optoelectronic pod inner frame heteroaxial mechanism

Abstract

The present invention relates to an inner frame heteroaxial mechanism of a two-axis four-frame optoelectronic pod, comprising an outer azimuth base, an outer azimuth axis system, an outer pitch U-shaped frame, an outer pitch left axis end, an outer pitch right axis end, an outer pitch ball frame, and an inner pitch left axis end; the centerline of the outer azimuth axis system coincides with the outer azimuth axis, the outer pitch U-shaped frame is connected to the outer azimuth base via the outer azimuth axis system and can rotate about the outer azimuth axis; the centerline of the outer pitch left axis end and the outer pitch right axis end forms an outer pitch axis, the outer pitch ball frame can rotate about the outer pitch axis relative to the outer pitch U-shaped frame; the centerline of the inner pitch left axis end and the inner pitch right axis end forms an inner pitch axis, the inner pitch frame can rotate about the inner pitch axis relative to the outer pitch ball frame; the centerline of the inner azimuth upper axis end and the inner azimuth lower axis end forms an inner azimuth axis, the load frame can rotate about the inner azimuth axis relative to the inner pitch frame; the load is mounted on the load frame. The present invention improves the overall performance of the optoelectronic pod.

Description

Technical Field

[0001] The invention relates to an inner-frame different-axis mechanism of a two-axis four-frame photoelectric pod, belonging to the technical field of photoelectric pods. Background Art

[0002] The existing two-axis four-frame optoelectronic pod is increasingly used in UAVs. Due to the limitations of the payload and flight time of UAVs, on the one hand, the performance indicators of the optoelectronic pod are sought to be improved, and on the other hand, the optoelectronic pod is hoped to be light and small.

[0003] The axis system of the traditional two-axis four-frame optoelectronic pod adopts a coaxial design of the inner frame rotating axis and the outer frame rotating axis, which strictly limits the position of the inner frame axis system. Due to the limitation of the load installation space, the center of mass of the load cannot be on the rotating axis. In order to strictly ensure the stability accuracy of the inner frame, the inner frame needs to be precisely balanced. It is often necessary to add a large amount of counterweight mass to achieve precise balancing, thereby increasing the overall weight.

[0004] The inner frame shaft system includes a supporting frame, bearings, rotor shaft and many other structures, which requires a lot of space. Due to the limitation of position, the load space is limited, and it is impossible to give the load more free space, which limits the improvement of optical load performance. Summary of the Invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology and propose an inner frame heteroaxial mechanism of a two-axis four-frame optoelectronic pod, which breaks the limitation of the inner frame axis system. The inner frame axis system can be designed according to the installation form and center of gravity position of the inner frame load, which can effectively utilize the internal space and reduce the mass of the inner frame counterweight. Under a given external size and weight, the design space and weight of the load are increased, and the overall performance of the optoelectronic pod is further improved.

[0006] The solution of the present invention is:

[0007] A two-axis four-frame optoelectronic pod inner frame different-axis mechanism, comprising an outer azimuth base, an outer azimuth axis system, an outer pitch U-shaped frame, an outer pitch left axis end, an outer pitch right axis end, an outer pitch ball frame, an inner pitch left axis end, an inner pitch right axis end, an inner pitch frame, an inner azimuth upper axis end, an inner azimuth lower axis end and a load frame;

[0008] The center line of the external orientation axis coincides with the external orientation axis, and the external pitch U-shaped frame is connected to the external orientation base through the external orientation axis and can rotate around the external orientation axis;

[0009] The center lines of the outer pitch left axis end and the outer pitch right axis end form an outer pitch axis, and the outer pitch ball frame can rotate around the outer pitch axis relative to the outer pitch U-shaped frame;

[0010] The inner pitch axis is formed by the centerline of the inner pitch left axis end and the inner pitch right axis end, and the inner pitch frame can rotate relative to the outer pitch ball frame around the inner pitch axis;

[0011] The inner orientation axis is formed by the center lines of the inner orientation upper axis end and the inner orientation lower axis end, and the load frame can rotate relative to the inner pitch frame around the inner orientation axis;

[0012] The payload is mounted on a payload frame.

[0013] Furthermore, the inner pitch axis formed by the center lines of the inner pitch left axis end and the inner pitch right axis end is not coaxial with the outer pitch axis and has a fixed offset.

[0014] Furthermore, the inner orientation axis formed by the center lines of the inner orientation upper shaft end and the inner orientation lower shaft end is not coaxial with the outer orientation axis and has a fixed offset.

[0015] Furthermore, the position of the inner pitch axis is determined by the position of the load center of mass and the load installation form.

[0016] Furthermore, the position of the inner azimuth axis is determined by the position of the load's center of mass and the load's installation form.

[0017] Furthermore, the external orientation base is a circular structure with a hole in the center. The axis of the center hole is the external orientation axis, and the external orientation axis is fixedly connected to the external orientation axis stator.

[0018] Furthermore, the bottom and two side vertical plates of the outer pitch U-shaped frame are opened with holes, and the vertical plate holes are coaxial holes; the azimuth shaft system rotor is coaxially fixedly connected to the U-shaped frame with the bottom holes, and the U-shaped frame can rotate around the azimuth base.

[0019] Furthermore, the holes on both sides of the U-shaped frame are coaxially installed with the stators at the right end of the outer pitch axis and the left end of the outer pitch axis to achieve relative rotation.

[0020] Furthermore, the outer pitch ball frame, inner pitch frame and load frame are rectangular structures; the outer pitch ball frame has positioning holes at the centers of both sides, and the axis of the positioning holes is the outer pitch axis, which is connected to the rotors at the outer pitch right axis end and the outer pitch left axis end to realize rotation around the U-shaped frame.

[0021] Furthermore, holes are opened at the centers of the upper and lower surfaces of the load frame, and the axis of the hole is the inner orientation axis. The upper and lower holes are positioned and connected to the rotors at the inner orientation upper shaft end and the inner orientation lower shaft end.

[0022] The beneficial effects of the present invention compared with the prior art are:

[0023] (1) The present invention can design the position of the inner frame's rotation axis according to the load's center of mass position, thereby achieving static balance of the inner frame and reducing the mass of the inner frame's counterweight;

[0024] (2) The present invention can design the position of the inner frame rotation axis according to the load size, which is flexible in design and can reasonably allocate space so that the optical load index is more matched;

[0025] (3) Under given external dimensions and weight, the design space and weight of the payload are increased to further improve the overall performance of the optoelectronic pod. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of a two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to the present invention;

[0027] Figure 2 This is a schematic diagram of the shafting relationship described in the present invention;

[0028] Figure 3 This is a cross-sectional view of a two-axis four-frame inner-frame hetero-axis optoelectronic pod described in the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the embodiments.

[0030] like Figure 1-3 As shown, it includes an external azimuth base 1, an external azimuth axis system 2, an external pitch U-shaped frame 3, an external pitch right axis end 4, an external pitch left axis end 5, an external pitch ball frame 6, an internal pitch left axis end 7, an internal pitch right axis end 8, an internal pitch frame 9, an internal azimuth upper axis end 10, an internal azimuth lower axis end 11, a load frame 12 and an optical load 13.

[0031] The center line of the external azimuth axis system 2 coincides with the external azimuth axis, and the external pitch U-shaped frame 3 is connected to the external azimuth base 1 through the external azimuth axis system 2 and rotates around the external azimuth axis; the center line of the external pitch right axis end 4 and the external pitch left axis end 5 forms an external pitch axis, and the external pitch ball frame 6 can rotate around the external pitch axis relative to the external pitch U-shaped frame 3; the center line of the inner pitch left axis end 7 and the inner pitch right axis end 8 forms an inner pitch axis, and the inner pitch frame can rotate around the inner pitch axis relative to the outer pitch ball frame; the center line of the inner azimuth upper axis end 10 and the inner azimuth lower axis end 11 forms an inner azimuth axis, and the load frame 12 can rotate around the inner azimuth axis relative to the inner pitch frame; the optical load 13 is installed on the load frame 12.

[0032] The optical payload 13 weighs 6 kg, with its center of mass offset by 1.5 mm from the outer azimuth axis and 7 mm from the outer pitch axis. The inner azimuth and inner pitch axes are designed to be coaxial with the optical payload's center of mass, offset by 1.5 mm and 7 mm from the outer azimuth and outer pitch axes, respectively. The optoelectronic pod has a spherical diameter of 280 mm. Assuming a trim radius of 100 mm, a coaxial design would require at least 0.51 kg of counterweight. Using an off-axis mechanism saves at least 0.51 kg of counterweight.

[0033] The external orientation base is a circular structure with a hole in the center. The axis of the center hole is the external orientation axis, which is fixedly connected to the external orientation shaft system stator. The shaft system structure is generally composed of a stator, a rotor, bearings, a motor, an angle measuring element, etc. The rotor can rotate around the axis relative to the stator.

[0034] The external pitch U-frame is U-shaped, with holes cut into the bottom and two side panels. The holes in the panels are coaxial. The azimuth shafting rotor is coaxially connected to the U-frame through the holes at the bottom, allowing the U-frame to rotate around the azimuth base.

[0035] The holes on both sides of the U-shaped frame are coaxially installed with the stators at the right and left ends of the external pitch axis to achieve relative rotation;

[0036] The outer pitch ball frame, inner pitch frame and load frame are rectangular structures; the outer pitch ball frame has a first positioning hole at the center of both sides. The axis of this first positioning hole is the outer pitch axis, which is connected to the rotors at the outer pitch right axis end and the outer pitch left axis end to realize rotation around the U-shaped frame.

[0037] Second positioning holes are opened on both sides of the outer pitch ball frame, offset from the first center hole. The distance that the second positioning holes offset from the first positioning holes depends on the distance that the center of gravity position of all structures in the inner pitch frame offsets from the outer pitch axis.

[0038] The stators at the left and right inner pitch shafts are positioned and connected to the second positioning holes on either side of the outer pitch ball frame. A hole is opened at the center of each side of the inner pitch frame, and the axis of the hole is the inner pitch axis. The two side holes are positioned and connected to the rotors at the left and right inner pitch shafts, enabling rotation around the inner pitch axis, with a rotation angle of generally ±3°.

[0039] A third positioning hole is opened at the center of the upper and lower surfaces of the inner pitch frame. The offset center distance of the third positioning hole is determined by the center of gravity of all structures within the load frame. The stators at the inner upper shaft end and the inner lower shaft end are respectively positioned and connected to the third positioning holes on the upper and lower surfaces of the inner pitch frame.

[0040] Holes are drilled in the center of the upper and lower surfaces of the load frame. The axis of the holes is the inner azimuth axis. The upper and lower holes are connected to the rotors at the inner azimuth upper and lower ends of the shaft. This allows the load frame to rotate around the inner azimuth axis relative to the inner pitch frame. The rotation angle is generally ±3°.

[0041] Restrictions:

[0042] Second positioning holes are opened on both sides of the outer pitch ball frame, offset from the first center hole. The distance that the second positioning holes offset from the first positioning holes depends on the distance that the center of gravity position of all structures in the inner pitch frame offsets from the outer pitch axis.

[0043] A third positioning hole is opened at the center of the upper and lower surfaces of the inner pitch frame, and the offset center distance of the third positioning hole is determined by the center of gravity position of all structures within the load frame.

[0044] Due to the limitations of the outer pitch ball frame, inner pitch frame structural dimensions, and rotation space, the offset distance is generally between 0 and 50 mm.

[0045] Working Principle: The electro-optical pod payload generally includes a visible light camera, an infrared thermal imager, and a laser light finder. These are installed on the innermost payload frame to achieve high stability of the line of sight relative to the inertial coordinate system. A three-axis gyroscope, sensitive to inertial information, is installed on the payload frame, sensing angular motion around the azimuth and pitch axes. A stabilization loop achieves a compensation rate to offset interference and stabilize the inner frame's line of sight. The outer frame follows the inner frame and is also used to isolate interference from external wind resistance. By utilizing the range of motion of the inner and outer frames, the azimuth and pitch of the inner frame can be kept perpendicular to each other, eliminating the blind spot problem of the self-locking ring frames of the two frames.

[0046] Unlike the coaxial inner frame mechanism of a conventional two-axis, four-frame optoelectronic pod, this invention achieves a skewed design by offsetting the inner frame's rotation axis from the outer frame's according to actual needs. This solves the problem of poor flexibility and low space utilization caused by the inner frame's axis system being constrained by the outer frame's axis system. Compared to conventional coaxial mechanisms of a two-axis, four-frame optoelectronic pod, this invention can design the inner frame's axis system based on the inner frame's load installation form and center of gravity position, effectively utilizing internal space and reducing the mass of the inner frame's counterweight. This increases the design space and weight of the payload within a given overall size and weight, further improving the overall performance of the optoelectronic pod.

[0047] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A two-axis four-frame optoelectronic pod inner frame different-axis mechanism, characterized in that: It comprises an external azimuth base (1), an external azimuth axis system (2), an external pitch U-shaped frame (3), an external pitch left axis end (4), an external pitch right axis end (5), an external pitch ball frame (6), an internal pitch left axis end (7), an internal pitch right axis end (8), an internal pitch frame (9), an internal azimuth upper axis end (10), an internal azimuth lower axis end (11) and a load frame (12); The center line of the external orientation axis system (2) coincides with the external orientation axis, and the external pitch U-shaped frame (3) is connected to the external orientation base (1) via the external orientation axis system (2) and can rotate around the external orientation axis; The center lines of the outer pitch left axis end (4) and the outer pitch right axis end (5) form an outer pitch axis, and the outer pitch ball frame (6) can rotate around the outer pitch axis relative to the outer pitch U-shaped frame (3); The inner pitch axis is formed by the center line of the inner pitch left axis end (7) and the inner pitch right axis end (8), and the inner pitch frame (9) can rotate relative to the outer pitch ball frame (6) around the inner pitch axis; The center lines of the inner azimuth upper shaft end (10) and the inner azimuth lower shaft end (11) form an inner azimuth axis, and the load frame (12) can rotate relative to the inner pitch frame (9); The load is mounted on a load frame (12).

2. The two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to claim 1 is characterized in that: The inner pitch axis formed by the center lines of the inner pitch left axis end (7) and the inner pitch right axis end (8) is not coaxial with the outer pitch axis and has a fixed offset.

3. The two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to claim 1, characterized in that: The inner orientation axis formed by the center lines of the inner orientation upper shaft end (10) and the inner orientation lower shaft end (11) is not coaxial with the outer orientation axis and has a fixed offset.

4. A two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to claim 1 or 2, characterized in that: The position of the inner pitch axis is determined by the position of the load's center of mass and the load's installation form.

5. A two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to claim 1 or 3, characterized in that: The position of the inner azimuth axis is determined by the position of the load's center of mass and the load's installation form.

6. The two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to claim 1, characterized in that: The external orientation base is a circular structure with a hole in the center. The axis of the center hole is the external orientation axis, and the external orientation axis is fixedly connected to the external orientation axis stator.

7. The two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to claim 1, characterized in that: The bottom and both side vertical plates of the external pitch U-shaped frame are opened with holes, and the vertical plate holes are coaxial holes; the azimuth shaft system rotor is coaxially fixedly connected to the U-shaped frame with the same bottom holes, and the U-shaped frame can rotate around the azimuth base.

8. The two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to claim 7, characterized in that: The holes on both sides of the U-shaped frame are coaxially installed with the stators at the right end of the outer pitch axis and the left end of the outer pitch axis to achieve relative rotation.

9. The two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to claim 1, characterized in that: The outer pitch ball frame, inner pitch frame and load frame are rectangular structures; the outer pitch ball frame has positioning holes at the center of both sides. The axis of this positioning hole is the outer pitch axis, which is connected to the rotors at the outer pitch right axis end and the outer pitch left axis end to realize rotation around the U-shaped frame.

10. The two-axis four-frame optoelectronic pod inner frame different-axis mechanism according to claim 1, characterized in that: Holes are opened at the centers of the upper and lower surfaces of the load frame, and the axis of the holes is the inner orientation axis. The upper and lower holes are positioned and connected with the rotors at the inner orientation upper shaft end and the inner orientation lower shaft end.

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