WO2018090300A1

WO2018090300A1 - A damping assembly

Info

Publication number: WO2018090300A1
Application number: PCT/CN2016/106290
Authority: WO
Inventors: Aibor HUANG
Original assignee: XDynamics Limited
Priority date: 2016-11-17
Filing date: 2016-11-17
Publication date: 2018-05-24

Abstract

A damping assembly for supporting a vibration sensitive component in an unmanned vehicle. The damping assembly(10) comprises at least one damping mass(20) arranged at a side of the vibration sensitive component(2); a housing(30) adapted to accommodate the damping mass(20) and the vibration sensitive component(2); wherein one or more damping means(40) are arranged in the housing(30) for isolating the damping mass(20) and the vibration sensitive component(2) from contacting the housing(30). An unmanned vehicle comprising the described damping assembly(10).

Description

A Damping Assembly

The invention relates to a damping assembly for use in an unmanned vehicle, and particularly, but not exclusively, to a damping assembly for use in an unmanned aerial vehicle such as a multi-copter.

There has been a rapid development in the field of unmanned vehicles and particularly, in the technology of unmanned aerial vehicles (UAV) such as multi-copters and drones. A conventional UAV may comprise one or more propellers controlled by a flight control computer having one or more controllers and/or sensors. These components are often sensitive to shocks and/or vibrations, which might generally be caused by intrinsic factors such as operation of the motors and/or propellers, as well as external factors such as wind buffeting and shocks resulting from landing and/or collisions with foreign objects. Particularly, it is common for the state of the art UAV to be equipped with one or more digital cameras or video cameras for taking aerial images and/or videos, and in this connection, it will be readily understandable that stability offered by shock absorbing and/or vibration damping functionality to the UAV will be of the essence.

Objects of the Invention

An object of the present invention is to provide a novel damping assembly for use in an unmanned aerial vehicle such as a multi-copter.

Another object of the present invention is to mitigate or obviate to some degree one or more problems associated with known unmanned aerial vehicles, or at least to provide a useful alternative.

The above objects are met by the combination of features of the main claim; the sub-claims disclose further advantageous embodiments of the invention.

One skilled in the art will derive from the following description other objects of the invention. Therefore, the foregoing statements of object are not exhaustive and serve merely to illustrate some of the many objects of the present invention.

In a first main aspect, the invention provides a damping assembly for supporting a vibration sensitive component in an unmanned vehicle, the damping assembly comprising: at least one damping mass arranged at a side of the vibration sensitive component; a housing adapted to accommodate the damping mass and the vibration sensitive component; wherein one or more damping means are arranged in the housing for isolating the damping mass and the vibration sensitive component from contacting the housing.

In a second main aspect, the invention provides an unmanned vehicle comprising a damping assembly according to the first main aspect.

In a third main aspect, the invention provides a damping assembly for supporting a printed circuit board carrying one or more vibration sensitive sensors in an electronic device, the damping assembly comprising: at least one damping means adapted to at least partially support the printed circuit board via at least one damping mass, a housing adapted to accommodate the printed circuit board and the at least one damping mass supported by the at least one damping means, wherein the at least one damping means is formed of a resilient material.

The summary of the invention does not necessarily disclose all the features essential for defining the invention; the invention may reside in a sub-combination of the disclosed features.

The foregoing and further features of the present invention will be apparent from the following description of preferred embodiments which are provided by way of example only in connection with the accompanying figure, of which:

Fig.1

is a top perspective view showing a damping assembly in accordance with one embodiment of the present invention;

Fig.2

is a bottom perspective view showing the damping assembly of Fig.1; and

Fig.3

is an exploded, bottom perspective view showing the damping assembly of Fig.1.

Description of Preferred Embodiments

The following description is of preferred embodiments by way of example only and without limitation to the combination of features necessary for carrying the invention into effect.

Reference in this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not other embodiments.

Referring to Figs. 1 to 3, shown is a damping assembly 10 in accordance with an embodiment of the present invention for supporting a vibration sensitive component 2 in an unmanned vehicle. The damping assembly 10 is adapted to be mounted on, for example, a printed circuit board (not shown) of an unmanned vehicle such as an unmanned aerial vehicle (UAV) which may be a multi-copter or a drone. A multi-copter is generally considered to be a remotely controlled unmanned aerial vehicle normally having four or more propellers, but having at least one pair of counter-rotating propellers thus negating the need for a tail rotor as required in most helicopters. In the context of the present description, the vibration sensitive component 2 may comprise a printed circuit board (PCB) having one or more electronic components which are sensitive to vibration. The vibration sensitive component 2 may further comprise a sensor chip or a sensor printed circuit board. In an embodiment where the damping assembly 10 is used in a multi-copter, the sensors may comprise one or more of a pressure sensor, a gyroscope, an accelerometer, a temperature sensor and/or a motion sensor, etc.

The damping assembly 10 may comprise at least one damping mass 20 arranged at a side of the vibration sensitive component 2. Preferably, the at least one damping mass 20 may comprise a first damping mass 21 and a second damping mass 22 arranged at opposing sides of the vibration sensitive component 2 such that the vibration sensitive component 2 is snugly sandwiched between the two damping

masses

21, 22. More preferably, the oppositely arranged first and

second damping masses

21, 22 are substantially aligned and are parallel to each other.

The at least one damping mass 20 is preferred to be formed of one or more non-magnetic materials to provide a counter weight for damping. More preferably, the damping mass 20 is formed of brass or austenitic stainless steel, or any non-magnetic alloy of brass or austenitic stainless steel, although other dense, non-magnetic and non-metallic materials may be used in some embodiments. It is preferred for the damping mass 20 to be formed of a non-magnetic material so as to avoid or at least reduce interference with any magnetic field-sensitive components in the vehicle.

Preferably, the damping mass 20 is provided with a weight in the range of about 5g to 20g, and more preferably in the range of about 8g to 15g. In the preferred embodiment as shown in the figures, the first damping mass 21 can be provided with a weight of about 10g and that the second damping mass 22 can be provided with a weight of about 8g, for example.

The damping assembly 10 may further comprise a housing 30 adapted to accommodate the

damping masses

21, 22 and the vibration sensitive component 2 therein. The housing 30 is preferred to be formed of any rigid, light weight, non-magnetic and non-metallic materials such as plastics. In one embodiment, the housing 30 may comprise a cover portion 32 and a base portion 34 cooperatively connectable to define an internal cavity 35 for accommodating the

damping masses

21, 22 and the vibration sensitive component 2. The cover portion 32 and the base portion 34 can be connected via one or more fastening means 39 such as via one or more screw connections. It is important to note that all the connection means or connection members such as screws and/or other mechanical fixings being used in the present invention should be non-magnetic and are preferably formed of a non-magnetic material such as brass, austenitic stainless steel or plastics to thereby avoid interference with any magnetic field-sensitive sensors such as a magnetometer.

As shown in the figures, one or more damping means 40 can be arranged in the housing 30 for supporting the

damping masses

21, 22 and the vibration sensitive component 2 and for isolating the

damping masses

21, 22 and the vibration sensitive component 2 from contacting the housing 30. Particularly, the damping means 40 is capable of providing damping to any vibrations transmitted from the unmanned vehicle to the supported component 2. The damping means 40 is preferred to be formed of one or more resilient materials such as, but not limited to: elastic polymers such as ethylene propylene diene monomer (EPDM) foam or rubber materials, silicone and/or thermoplastic elastomers (TPE), etc. In one preferred embodiment, the resilient material may comprise one or more of the following physical properties, including a density of about 50 kg/m3 to about 110 kg/m3; a tensile strength of more than or equal to about 0.1 MPa; a fracture strain of more than or equal to about 150%; a tear strain of more than or equal to about 0.5 KN/m; a heat shrink rate of less than or equal to about 3%; a 25% compression deformation load of about 40 kg/100cm2 to about 70 kg/100cm2, for example.

Preferably, the one or more damping means 40 may comprise at least one first damping means 41 and at least one second damping means 42, with the at least one first damping means 41 being arranged between the first damping mass 21 and a first inner wall 36 of the housing 30, and the at least one second damping means 42 being arranged between the second damping mass 22 and a second, opposing inner wall 38 of the housing 30. More preferably, the first inner wall 36 can be provided at the cover portion 32 and that the second inner wall 38 can be provided at the base portion 34 of the housing 30.

Specifically, the at least one first damping means 41 is adapted to at least partially support the vibration sensitive component 2 via the first damping mass 21, and that the at least one second damping means 42 is adapted to at least partially support the vibration sensitive component 2 via the second damping mass 22. Preferably, one or more of the at least one first damping means 41 and the at least one second damping means 42 are arranged to partially support the vibration sensitive component 2 via one or more of the respective first and

second damping masses

21, 22 at one or more peripheral edges of the support surfaces of the

corresponding damping masses

21, 22. For example, the at least one first damping means 41 and the at least one second damping means 42 are arranged to partially support the vibration sensitive component 2 via the respective first and

second damping masses

21, 22 at one or more corners thereof. More preferably, the at least one first damping means 41 and the at least one second damping means 42 may comprise four pairs of oppositely arranged and substantially aligned first and second damping means 41, 42 located at four respective corners of the corresponding

quadrilateral damping masses

21, 22, as shown in the figures.

In use, the first and the second damping means 41, 42 are subjected to compression by and between the

corresponding damping masses

21, 22 and the respective

inner walls

36, 38 of the housing 30. Preferably, the damping assembly 10 is configured to allow no more than 50% of compression of the first and the second damping means 41, 42 to thereby allow a sufficient damping effect by the

damping masses

21, 22 to the supported vibration sensitive component 2. For example, in one specific embodiment, the first and the second damping means 41, 42 may each be provided in the shape of a cubic prism, with the first damping means 41 having a dimension of about 6mm in length, about 6mm in width and about 5mm in height, and the second damping means 42 having a dimension of about 6mm in length, about 6mm in width, and about 3 mm in height at their relaxed, non-compressed conditions. Upon being positioned in the housing 30, it is preferred that the first damping means 41 and the second damping means 42 be compressed such that the respective height be reduced from about 5mm to about 2.5mn, and from about 3mm to about 1.5mm, respectively. Nevertheless, a person skilled in the art will appreciate that the degree of compression of a resilient material is highly dependent on its specific physical properties such as resiliency and hardness, and therefore, the described degree of compression and thus the reduction in dimension of the damping means may serve only as an example of a specific embodiment. It will be understandable that any other types or forms of resilient materials which demonstrate different compression or damping behaviors shall also be encompassed by the present invention, as long as they are capable of preventing or reducing vibrations from the vehicle to be transmitted to the supported vibration sensitive component 2.

In one embodiment, the area of contact between the first and second damping means 41, 42 and the corresponding first and

second damping masses

21, 22 is preferred to be less than 50% of the area of the support surface of the

corresponding damping masses

21, 22, and more preferably, less than 30%. The reduced contact area is beneficial in reducing the transmission of any generated vibrations from the unmanned vehicle via the damping means to the supported component 2.

In another embodiment, one or more of the damping

masses

21, 22 may further comprise a cavity (not shown) at a side facing the vibration sensitive component 2, with the cavity being configured to accommodate one or more parts arranged at the side of the vibration sensitive component 2 facing the cavity. The first and the second damping

masses

21, 22 may cooperatively define an enclosure to thereby substantially enclose the one or more parts of the vibration sensitive component 2. The one or more parts can be one or more sensors electrically mounted on one side of the sensor chip or the sensor printed circuit board of the vibration sensitive component 2 arranged to face into the cavity and/or the enclosure to thereby prevent any adverse effects to the detection or other functions of the sensors by external factors such as air turbulence, as well as to allow physical protection of these sensitive parts. Yet at least one of the first and the second damping

masses

21, 22 may optionally be provided with one or more aperture to thereby allow fluid communication between an interior and an exterior of the cavity and/or the enclosure and thus to equalize the atmospheric conditions, e.g. pressure, between the exterior and the interior of the cavity and/or the enclosure in which the sensors are substantially enclosed, for example, for the purpose of pressure sensing during a flight, etc.

In one further embodiment, one or more of the damping

masses

21, 22 can be configured to comprise an opening 44 which allows one or more electronic connections such as a ribbon cable 70 to connect one or more enclosed parts of the vibration sensitive component 2 with one or more other electronic components outside the damping assembly 10 such as another printed circuit board of the vehicle. The ribbon cable 70 can be allowed to exit the housing 30 via, for example, an outlet 53 of the housing 30.

In yet a further embodiment, the damping assembly 10 can be mounted at a part of the unmanned vehicle via at least one mount 50 provided at the housing 30 or preferably, the base portion 34 of the housing 30. The at least one mount 50 may comprise at least one connection portion 52 configured with a height to thereby lift the assembly 10 sufficiently above a surface of the part of the unmanned vehicle. This arrangement is beneficial to reduce or minimize direct contact between the assembly 10 and the part of the vehicle and thus, further prevent or reduce vibrations from the vehicle being transmitted to the supported component 2. The housing 30 may further comprise one or more recesses or protrusions 37 adapted to receive or engage at least partially the one or more damping means 41, 42 to thereby position the damping means 41, 42 at housing 30, as shown in Fig. 3.

The present invention also relates to an unmanned vehicle which comprises the damping assembly 10 as described above. The unmanned vehicle can be a multi-copter having at least one pair of counter-rotating propellers, and preferably, the multi-copter is provided in the form of a drone configured for remotely piloted and/or autonomous flight.

The present invention is advantageous in that it provides a simple, compact and light-weighted damping assembly adapted to substantially reduce or prevent the transmission of mechanical vibrations generated by an unmanned aerial vehicle during a flight to one or more vibration sensitive components carried by the vehicle. Particularly, the resilient damping means of the present invention, when cooperating with one or more of the damping masses having certain counter balance weights, allows an effective damping to mechanical vibrations. More particularly, the resiliency of the damping means and/or the weight of one or more of the damping masses can be adjusted or customized to offer damping or preferably critical damping for different ranges of vibration frequencies including the mechanical vibrations typically generated by one or more of the propellers, the motor and/or other movable parts of the multi-copter or drone, as well as the frequencies of vibrations experienced by the aerial vehicle due to the exterior conditions such as vibrations generated by wind during a flight. Furthermore, the damping masses define an enclosure which substantially shields the sensors provided at the supported printed circuit board from the effect of air turbulence, with the outer housing being capable of further reducing any interfering direct air current as well as providing physical protection to the enclosed printed circuit board. The damping to vibrations and the air-turbulence shielding function allow improved data to be collected by the unmanned aerial vehicle, with the noise component of the data being substantially reduced or minimized.

In an unmanned vehicle in accordance with the invention, the vehicle will typically be provided with a camera. The camera is typically mounted to the vehicle by a separate, independent vibration suppression or damping system to that hereinbefore described. An unexpected advantage of substantially reducing the transmission of vibrations to the sensors of the vehicle using the damping system hereinbefore described is that this results in improved flight control as the sensors readings are also more stable and reliable being less affected by vibrations than typically encountered in prior art vehicles. Such improved flight control improves the flight stability of the vehicle as a whole and consequently lessens vibrations affecting the vehicle. This in turn improves the quality of images captured by the camera and also allows the separate damping system of the camera to more readily dampen or suppress any vibrations that may be transmitted to the camera.

The present description illustrates the principles of the present invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope.

Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only exemplary embodiments have been shown and described and do not limit the scope of the invention in any manner. It can be appreciated that any of the features described herein may be used with any embodiment. The illustrative embodiments are not exclusive of each other or of other embodiments not recited herein. Accordingly, the invention also provides embodiments that comprise combinations of one or more of the illustrative embodiments described above. Modifications and variations of the invention as herein set forth can be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated by the appended claims.

In the claims hereof, any element expressed as a means for performing a specified function is intended to encompass any way of performing that function. The invention as defined by such claims resides in the fact that the functionalities provided by the various recited means are combined and brought together in the manner which the claims call for. It is thus regarded that any means that can provide those functionalities are equivalent to those shown herein.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

It is to be understood that, if any prior art is referred to herein, such prior art does not constitute an admission that the prior art forms a part of the common general knowledge in the art.

Claims

A damping assembly for supporting a vibration sensitive component in an unmanned vehicle, the damping assembly comprising:
at least one damping mass arranged at a side of the vibration sensitive component;
a housing adapted to accommodate the damping mass and the vibration sensitive component;
wherein one or more damping means are arranged in the housing for isolating the damping mass and the vibration sensitive component from contacting the housing.
The damping assembly according to claim 1, wherein the at least one damping mass comprises a first damping mass and a second damping mass arranged at opposing sides of the vibration sensitive component.
The damping assembly according to claim 2, wherein the one or more damping means comprise at least one first damping means and at least one second damping means, with the at least one first damping means being arranged between the first damping mass and a first inner wall of the housing, and the at least one second damping means being arranged between the second damping mass and a second, opposing inner wall of the housing.
The damping assembly according to claim 3, wherein the housing comprises a cover portion and a base portion, with the first inner wall being provided at the cover portion and the second inner wall being provided at the base portion.
The damping assembly according to claim 2, wherein the at least one first damping means is adapted to at least partially support the vibration sensitive component via the first damping mass.
The damping assembly according to claim 2, wherein the at least one second damping means is adapted to at least partially support the vibration sensitive component via the second damping mass.
The damping assembly according to claim 5 or 6, wherein one or more of the at least one first damping means and the at least one second damping means are arranged to support the vibration sensitive component via one or more of the respective first and second damping masses at one or more peripheral edges thereof.
The damping assembly according to claim 5 or 6, wherein one or more of the at least one first damping means and the at least one second damping means are arranged to support the vibration sensitive component via one or more of the respective first and second damping masses at one or more corners thereof.
The damping assembly according to claim 1, wherein the one or more damping means is formed of a resilient material.
The damping assembly according to claim 1, wherein the damping mass comprises a cavity at a side facing the vibration sensitive component, the cavity is adapted to accommodate one or more parts arranged at a side of the vibration sensitive component facing the cavity.
The damping assembly according to claim 2, wherein the first and the second damping masses cooperatively define an enclosure to thereby substantially enclose one or more parts arranged at the vibration sensitive component.
The damping assembly according to claim 4, wherein the base portion comprises at least one mount for mounting the assembly at a part of the unmanned vehicle.
The damping assembly according to claim 12, wherein the at least one mount comprises at least one connection portion configured with a height to thereby lift the assembly above a surface of the part of the unmanned vehicle.
The damping assembly according to claim 11, further comprising an aperture provided at at least one of the first and the second damping masses to thereby allow fluid communication between an interior and an exterior of the enclosure.
The damping assembly according to claim 4, wherein the cover portion and the base portion are connected via one or more fastening means.
An unmanned vehicle, comprising a damping assembly according to claim 1.
The unmanned vehicle according to claim 16, wherein the unmanned vehicle is a multi-copter having at least one pair of counter-rotating propellers.
The unmanned vehicle according to claim 17, wherein the multi-copter is configured for autonomous flight.
A damping assembly for supporting a printed circuit board carrying one or more vibration sensitive sensors in an electronic device, the damping assembly comprising:
at least one damping means adapted to at least partially support the printed circuit board via at least one damping mass,
a housing adapted to accommodate the printed circuit board and the at least one damping mass supported by the at least one damping means,
wherein the at least one damping means is formed of a resilient material.