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The present disclosure relates to a gimbal photographing technology field and, more particularly, to a vibration reduction device and a gimbal system.
A gimbal is a supporting device to fix an image acquisition device such as a camera, a video recorder, etc., and is used to improve a stability of the image acquisition device. The gimbal has a multi-frame tandem structure and has many vibration modes (i.e., resonance points). A mechanical response of the gimbal is quite different from a theoretical rigid body response due to the existing vibration modes, which leads to a difficulty in control design. These vibration modes also cause the mechanical system to multiply an interference on the gimbal when an external disturbance is near a modal frequency, so that the vibration of the gimbal increases and photographing quality of the image acquisition devices is affected.
In accordance with the disclosure, there is provided a vibration reduction device including a bracket configured to be mounted at a gimbal, a counterweight component movably connected to the bracket, and a damping material arranged between the bracket and the counterweight component. The counterweight component and the bracket are configured to move relative to each other when the bracket is subject to vibration, to drive the damping material to flow.
In addition, the respective figures are not necessarily drawn to scale, but are shown illustratively in a manner that does not affect the reader's understanding.
The embodiments of the present disclosure are described in detail in connection with the drawings. Other aspects, advantages, and prominent features of the present disclosure are apparent to one of ordinary skill in the art.
In the present disclosure, the following various embodiments describing the principles of the present disclosure are only illustrative, and should not be construed as limiting the scope of the present disclosure in any way. The following description with reference to the accompanying drawings is used to assist in a comprehensive understanding of example embodiments of the present disclosure. The following description includes a plurality of specific details to help understand, and these details should be only construed as illustrative. One of ordinary skill in the art should realize that the described embodiments may be changed or modified without departing from the scope and spirit of the present disclosure. In addition, the description of the well-known functions and structures is omitted for clarity and simplicity. The same reference numerals are used for the same or similar functions and operations throughout the drawings. Although schemes with different features are described in different embodiments, those of ordinary skill in the art should understand that all or a part of features of different embodiments may be combined to form new embodiments without departing from the spirit and scope of this disclosure.
One of ordinary skill in the art should understand, “vibration mode” is an inherent vibration characteristic of a structure or a component, and each mode has a specific natural frequency, a damping ratio, and a modal shape. When a vibration frequency of an external vibration or a vibration frequency of an excitation vibration is equal to the natural frequency of the structure or the component, a resonance will happen. An amplitude is amplified during the resonance. In this context, the amplitude at which the structure or the component resonates is described as a “resonant amplitude.”
In the context, “broadband” or “broadband range” indicate a frequency range formed by natural frequencies of a plurality of vibration modes, rather than a single natural frequency of a certain vibration mode.
In the present disclosure, a “movement plane” of a component indicates a plane of the component moving relative to an adjacent component.
In the context, when describing a vibration reduction device, X-Y-Z coordinate system is established to describe different directions. The directional expression is for convenience of description only, rather than for restriction of the embodiments in the present disclosure. X direction, Y direction and Z direction may be any directions, as long as they are perpendicular to each other. For example, when the vibration reduction device is mounted at a gimbal, X direction may be parallel to the pitch axis of the gimbal, Y direction may be parallel to the roll axis of the gimbal, and Z direction may be parallel to the yaw axis of the gimbal.
The technology described in the present disclosure may be implemented on a gimbal. Generally, the gimbal can be configured to carry a load, such as an imaging device. The imaging device may be a camera, a video recorder, or a lens, etc. The gimbal may be mounted at a moving object, for example, an unmanned aerial vehicle (UAV), a movable rail car, or an unmanned vehicle. When the gimbal is held by a user, the gimbal becomes a handheld device.
Refer to
In the embodiments, when the vibration reduction device 10 is mounted at the vibrating component, for example, when the bracket 12 of the vibration reduction device 10 is mounted at a place with a relatively high or a highest resonance amplitude of the vibrating component and the vibrating component vibrates, the bracket 12 will vibrate with the vibrating component. Since the counterweight component 14 and the bracket 12 are movably connected and the counterweight component 14 is heavy, the counterweight component 14 tends to keep still due to the inertial effect of the counterweight component 14. Therefore, relative movement occurs between the bracket 12 and the counterweight component 14, causing the damping material 16 between counterweight component 14 and bracket 12 to flow. The damping material 16 may absorb vibration energy to reduce and even eliminate the vibration of the vibrating component at this place. The heavier the counterweight component 14 is, the stronger is the ability of the counterweight component 14 to keep still due to the inertial effect, and the more possibly the relative movement between the bracket 12 and the counterweight component 14 would occur.
On the other hand, a conventional dynamic vibration absorber generally includes at least a mass block and a spring. Through a dynamic function of the mass block, the force generated by the spring of the vibration absorber on a main system can offset a part or most of the external excitation force applied to the main system to reduce the vibration of the main system, which is equivalent to transferring the vibration energy of the main system to the dynamic vibration absorber. Due to the reliance on the function of the spring, the conventional dynamic vibration absorber is usually configured to absorb the vibration of the natural frequency under a certain vibration mode, i.e., the vibration reduction is restricted to a single vibration mode. In comparison, in a vibration reduction device based on the principles of the present disclosure, the damping material is between the counterweight component and the bracket that can move relative to each other, which allows the vibration reduction device to absorb vibrations of a broadband. In the embodiments of the present disclosure, the vibration reduction device does not need to include a spring and is not restricted to only absorbing or reducing the vibration of the natural frequency under a certain single vibration mode.
In an example embodiment, the vibration reduction device 10 further includes a gap maintaining component 18, the bracket 12 includes at least one first movement plane 121, and the counterweight component 14 includes at least one second movement plane 141. The gap maintaining component 18 allows the first movement plane 121 of the bracket 12 to move relative to the second movement plane 141 of the counterweight component 14 with a pre-set gap. The gap maintaining component 18 is configured to maintain the pre-set gap between the first movement plane 121 of the bracket 12 and the second movement plane 141 of the counterweight component 14, when the first movement plane 121 of the bracket 12 moves relative to the second movement plane 141 of the counterweight component 14.
In an embodiment, the damping material 16 may include a semi-liquid damping material, e.g., a damping grease. The damping material 16 may be between the first movement plane 121 of the bracket 12 and the second movement plane 141 of the counterweight component 14.
In some embodiments, as shown in
In some embodiments, the gap maintaining component 18 may be a rolling component or an elastic component. For example, the rolling component may include at least one of a ball, a needle, or a roller. The elastic component may include a spring or a thin steel sheet, etc.
In the embodiment shown in
In some other embodiments, the mounting slot may be arranged to one of the first movement plane 121 of the bracket 12 and the second movement plane 141 of the counterweight component 14 for accommodating the rolling component, i.e., the mounting slot 123 is only arranged at the first movement plane 121 of the bracket 12 for accommodating the rolling component, or the mounting slot 143 is only arranged at the second movement plane 141 of the counterweight component 14 for accommodating the rolling component. The rolling component may be arranged in the mounting slot 123 or the mounting slot 143, and the first thickness of the rolling component is larger than the first depth of the mounting slot 123 or the second depth of the mounting slot 143. The gap 15 may still be formed between the first movement plane 121 and the second movement plane 141 through this manner, and the difference between the first thickness of the rolling component and the first depth or the second depth forms the pre-set dimension of the gap 15.
When the pre-set dimension (i.e., pre-set gap) of the gap 15 falls in the range of 0.2-2 mm, the damping material 16 in the gap 15 may provide the damping force that satisfies pre-set requirements. Further, to precisely control the damping force generated by the damping material 16, the damping material 16 may be filled merely in the gap 15 between the bracket 12 and the counterweight component 14 along the Z direction.
In some embodiments, the gap maintaining component 18 may be arranged between the bracket 12 and the counterweight component 14. For example, when the gap maintaining component 18 is the rolling component, the rolling component may be between the first movement plane 121 of the bracket 12 and the second movement plane 141 of the counterweight component 14.
In some other embodiments, for example, when the gap maintaining component 18 is the elastic component (e.g., springs, or thin steel sheet), the elastic component may be arranged in positions other than the position between the first movement plane 121 of the bracket 12 and the second movement plane 141 of the counterweight component 14, as long as the elastic component can maintain the gap 15 between the first movement plane 121 and the second movement plane 141. Similar to the rolling component described above, the elastic component is configured to maintain the gap 15 between the first movement plane 121 and the second movement plane 141 to ensure the damping force provided by the damping material 16 in the gap 15 satisfies the pre-set requirements.
With further reference to
The first movement plane 121 may be formed at the protrusion 122 of the bracket 12, the second movement plane 141 may formed at the inner wall of the chamber of the counterweight component 14, and the gap maintaining component 18 allows the first movement plane 122 formed at the protrusion 122 and the second movement plane 144 formed at the inner wall of the chamber to move relative to each other with the pre-set gap. The bracket 12 further includes a mounting member 124 connected to the protrusion 122 and is mounted at the vibrating component through the mounting member 124.
In some embodiments, as shown in
Each protrusion 122 forms a cantilever structure and, as shown in the figure, each protrusion 122 has two first movement planes 121. Each counterweight component 14 includes the first counterweight member 142 and the second counterweight member 144. The surface of the first counterweight member 142 facing the first movement plane 121 forms a second movement plane 141, and the surface of the second counterweight member 144 facing the other first movement plane 121 forms another second movement plane 141. A gap 15 is formed between one first movement plane 121 and one corresponding second movement plane 141, and the damping material 16 is filled in the gap 15. Another gap 15 is formed between the other first movement plane 121 and the corresponding second movement plane 141, and the damping material 16 is also filled in the other gap 15. With the damping material 16 filled to both sides of the protrusion 122, the damping force may be better provided for the relative movement of the bracket 12 and the counterweight component 14 to achieve the better effect of vibration reduction.
The mounting member 124 of the bracket 12 may be formed with various structures that can appropriately match the vibrating component. In the embodiment shown in the figure, the mounting member 124 is formed as a closed structure with a rounded triangle shape to surround and be connected with the vibrating component.
In some other embodiments, the vibration reduction device 10 may include more (e.g., more than two) counterweight components 14. The plurality of counterweight components 14 are symmetrically distributed and movably connected to the bracket 12. For example, as shown in
Referring again to
In one embodiment, the engagement component 1264 may have an arc shape to be suitable for engaging with a shaft of the vibrating component.
As shown in
In an example embodiment, the vibration reduction device 20 further includes a gap maintaining component 28. The bracket 22 includes at least one first movement plane 221, the counterweight component 24 include at least one second movement plane 241, and the gap maintaining component 28 allows the first movement plane 221 of the bracket 22 to move relative to the second movement plane 241 of the counterweight component 24 with a pre-set gap.
In the embodiment shown in the figure, the first movement plane 221 is formed at the inner wall of the receiving chamber of the bracket 22, the second movement plane 241 is formed at the surface of the counterweight component 24 facing the inner wall, and the gap maintaining component 28 allows the first movement plane 221 at the inner wall of the receiving chamber to move relative to the second movement plane 241 at the counterweight component 24 with the pre-set gap.
In one embodiment, the damping material 26 may include a semi-liquid damping material, e.g., a damping grease. The damping material 26 may be between the first movement plane 221 of the bracket 22 and the second movement plane of the counterweight component 24.
In some embodiments, the bracket 22 may include a first cover 2251 and a second cover 2252, where the first cover 2251 and the second cover 2252 are connected to form a receiving chamber. The bracket 22 may further include a sealing component, so that the counterweight component 24 may be sealed and accommodated in the receiving chamber to prevent the damping material 26 from contamination of external moisture, dust, etc.
In one embodiment, the first cover 2251 and the second cover 2252 may be connected removably, for example, connected through bolts, screws, etc., so that the first cover 2251 and the second cover 2252 may be separated to open the receiving chamber, or be engaged to close the receiving chamber.
The bracket 22 may include a mounting member 224, which is configured to mount the bracket 22 at the vibrating component. The second cover 2252 may include at least one support arm, for example, two support arms 2281 and 2282, and both support arms 2281 and 2282 are connected to the mounting member 224.
The shape of the mounting member 224 may be similar with the shape of the mounting member 124, which is not described in detail here.
In one embodiment, the second cover 2252 and the support arms 2281 and 2282 may be integrated into one, the support arms 2281 and 2282 are connected to the mounting member 224 with bolts, etc. As shown in the figure, the second cover 2252 and two support arms 2281 and 2282 may form a “C” shape structure, the mounting member 224 may be sandwiched between the openings of the “C” shape structure.
In the embodiment, the gap maintaining component 28 may be a rolling component or an elastic component. For example, the rolling component may include at least one of a ball, a needle, and a roller. The elastic component may include a spring or a thin steel sheet, etc.
In the embodiment, shown in the figure, the gap maintaining component 28 is the rolling component, the first movement plane 221 of the bracket is configured with a mounting slot to accommodate the rolling component, the second movement plane 241 of the counterweight component 24 is configured with a mounting slot to accommodate the rolling component. The mounting slot at the first movement plane 221 and the mounting slot at the second movement plane 241 corporate to form a receiving component to receive or accommodate the one rolling component. To form the gap 25, along the Z direction, the mounting slot at the first movement plane 221 has a first depth (i.e., recessed dimension), the mounting slot at the second movement plane 241 has a second depth (i.e., recessed dimension), the rolling component may have a first thickness, the first thickness of the rolling component is larger than the sum of the first depth and the second depth. The difference between the first thickness of the rolling component and the sum of the first depth and the second depth forms the pre-set dimension of the gap 25.
In some other embodiments, the mounting slot may be arranged at one of the first movement plane 221 of the bracket 22 and the second movement plane 241 of the counterweight component 24 for accommodating the rolling component, i.e., the mounting slot is only arranged at the first movement plane 221 of the bracket 22 for accommodating the rolling component, or the mounting slot is only arranged at the second movement plane 241 of the counterweight component 24 for accommodating the rolling component. The rolling component may be arranged in the mounting slot at the bracket or in the mounting slot at the counterweight component, and the first thickness of the rolling component is larger than the first depth of the mounting slot at the bracket or the second depth of the mounting slot at the counterweight component. The gap 25 may still be formed between the first movement plane 221 and the second movement plane 241 through this manner, and the difference between the first thickness of the rolling component and the first depth or the second depth forms the pre-set dimension of the gap 25.
When the pre-set dimension (i.e., pre-set gap) of the gap 25 falls in the range of 0.2-2 mm, the damping material 26 in the gap 25 may provide the damping force to satisfy the pre-set requirements. To precisely control the damping force generated by the damping material 26, the damping material 26 may only be filled in the gap 25 between the bracket 22 and the counterweight component 24 along the Z direction, but not filled in the other gaps between the bracket 22 and the counterweight component 24.
In some embodiments, the gap maintaining component 28 may be between the bracket 22 and the counterweight component 24. For example, when the gap maintaining component 28 is the rolling component, the rolling component may be between the first movement plane 221 at the bracket 22 and the second movement plane 241 at the counterweight component 24.
In some other embodiments, for example, when the gap maintaining component 28 is the elastic component (e.g., spring, or thin steel sheet), the elastic component may be arranged in positions other than the position between the first movement plane 221 at the bracket 22 and the second movement plane 241 at the counterweight component 24, as long as the elastic component may maintain the gap 25 between the first movement plane 221 and the second movement plane 241.
In some embodiments, the two first movement planes 221 at the bracket 22 are formed at the inner surface of the first cover 2251 facing the counterweight component 24 and at the inner surface of the second cover 2252 facing the counterweight component 24, respectively. The two surfaces of counterweight component 24 facing the two first movement planes 221 (i.e., as shown in
In some embodiments, when the gap maintaining component 28 is a ball, at least three balls may be arranged between the first movement plane 221 and the corresponding second movement plane 241. Since three balls can determine a plane, a consistent gap between the whole first movement plane 221 and the corresponding second movement plane 241 can be ensured. In the embodiment shown in the figure, for example, eight balls are arranged between the first movement plane 221 and the corresponding second movement plane 241. When the gap maintaining component 28 is the needle or the roller, at least three needles or rollers may be provided, and the consistent gap between the whole first movement plane 221 and the corresponding second movement plane 241 may still be ensured to be formed.
Referring again to
The vibration reduction devices 10 and 20 consistent with embodiments of the disclosure are described above in connection with the figures. Hereinafter, the embodiments of the disclosure are further described in connection with specific application scenarios.
In embodiments of the present disclosure, the vibration reduction device 10 is mounted at the gimbal 100, as shown in
When the gimbal 100 is used for photographing, the yaw axis arm 1002 has large vibration amplitude, and the phenomena with large vibration amplitude is especially obvious at an end 1002A of the yaw axis arm 1002 away from the load support component. In some embodiments of the present disclosure, as shown in
Since the gimbal has the multi-frame tandem structure and the gimbal has many vibration modes, in embodiments of the present disclosure, the vibration reduction device is especially suitable for the gimbal. The vibration reduction device may reduce the resonance amplitude of the natural frequencies under the plurality of vibration modes to provide an effective vibration reduction effect for the gimbal.
In some embodiments, the gimbal 100 further includes a balance adjustment device 1012 at the yaw axis arm. In some embodiments, the balance adjustment device at the yaw axis arm 1012 may be configured to mount batteries, i.e., to form a battery station. The vibration reduction device 10 arranged at the yaw axis arm 1002 and the balance adjustment device 1012 may be arranged at two sides of the yaw axis arm, respectively, i.e., two sides of the yaw axis. The balance of the yaw axis arm is better achieved, and the balance of the gimbal is better ensured.
In another embodiment, the vibration reduction device 20 is mounted at a gimbal 200, as shown in
When the gimbal 200 is used for photographing, the vibration amplitude of the yaw axis arm 2002 is relatively large, and the phenomena of the large vibration amplitude is obvious at an end 2002A of the yaw axis arm 2002 away from the load support component. In some embodiments of the present disclosure, as shown in
Since the gimbal has the multi-frame tandem structure and the gimbal has many vibration modes, in embodiments of the present disclosure, the vibration reduction device is especially suitable for the gimbal to reduce the resonance amplitude of the natural frequencies under the plurality of vibration modes and provide an effective effect for the vibration reduction.
In some embodiments, the gimbal 200 further includes a yaw axis arm balance adjustment device 2012. In some embodiments, the yaw axis arm balance adjustment device 2012 may also be configured to mount batteries, i.e., to form a battery station. The vibration reduction device 20 arranged at the yaw axis arm 2002 and the balance adjustment device 2012 may be arranged at the two sides of the yaw axis arm, respectively, i.e., the two sides of the axis of the yaw axis arm. In this way, the balance of the yaw axis arm may be better achieved, and the balance of the gimbal is better ensured.
In accordance with some other embodiments, there is provided a gimbal system, and the gimbal system includes the gimbal 100, 200 described above and the vibration reduction device 10, 20 described above.
In one embodiment, the gimbal system may include at least two of the vibration reduction device 10, 20, and at least one of the at least two of the vibration reduction device 10, 20 is mounted at the yaw axis arm 1002, 2002.
In another embodiment, the gimbal system may include three of the vibration reduction device 10, 20, and the three of the vibration reduction device 10, 20 are mounted at the yaw axis arm 1002/2002, the roll axis arm 1004/2004, and the pitch axis arm 1006/2006, respectively.
In accordance with the embodiments above, with the vibration reduction device mounted at the gimbal, the vibration amplitudes of the plurality of vibration modes may be reduced in the broadband range, the active vibration suppression performance of the gimbal is improved, and the sensitivity to the vibration disturbance of the gimbal is reduced.
Although the present disclosure is described with reference to the specific example embodiments, one of ordinary skill in the art should understand that various changes to the form and the detail of the present disclosure may be implemented without departing from the spirit and scope of the disclosure. The scope of the present disclosure is not limited to the embodiments above. A true scope and spirit of the invention is indicated by the following claims and their equivalents.
This application is a continuation of International Application No. PCT/CN2017/099933, filed Aug. 31, 2017, the entire content of which is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2017/099933 | Aug 2017 | US |
Child | 16801979 | US |