A multi-rotor aircraft comprising a controller, an annular airframe, at least two first rotor units and at least two actuation components. Wherein, the annular airframe comprises at least two frames and at least two connecting units, the adjacent frames are movably connected by the connecting unit; the first rotor units are arranged on the annular airframe and are electrically connected with the controller, the first rotor units are used to provide lift for the multi-rotor aircraft to fly; the actuation components are arranged on the annular airframe and are electrically connected with the controller; when the multi-rotor aircraft flies, the actuation components are used for driving the adjacent frames to move away from each other or to move close to each other, so as to enlarge or reduce the enclosed area of the annular airframe respectively.

TECHNICAL FIELD

The present disclosure belongs to the technical field of aircraft, and particularly relates to multi-rotor aircraft.

BACKGROUND

At present, a large multi-rotor aircraft is increasingly for civil use, however, the large multi-rotor aircraft needs a large-area site in the process of taking-off and landing, which makes the application scope of the large multi-rotor aircraft limited.

If an automatic storage apparatus is used for accommodating the large multi-rotor aircraft, that is, the automatic storage apparatus is used for the large multi-rotor aircraft to take off and to lands on, and is also used for automatically storing and charging the large multi-rotor aircraft, accordingly, the automatic storage apparatus also needs to be a large one, thus significantly increasing the cost of designing and manufacturing the automatic storage apparatus, and also increasing the difficulty of transporting and installing the automatic storage apparatus.

SUMMARY

As such, the present disclosure proposes a multi-rotor aircraft, the multi-rotor aircraft comprises a controller, an annular airframe, at least two first rotor units and at least two actuation components. Wherein, the annular airframe comprises at least two frames and at least two connecting units, the adjacent frames are movably connected by the connecting unit; the first rotor units are arranged on the annular airframe and are electrically connected with the controller, the first rotor units are used to provide lift for the multi-rotor aircraft to fly; the actuation components are arranged on the annular airframe and are electrically connected with the controller; when the multi-rotor aircraft flies, the actuation components are used for driving the adjacent frames to move away from each other or to move close to each other, so as to enlarge or reduce the enclosed area of the annular airframe respectively.

Details of one or more embodiments of the invention are provided in the following drawings and description. Other features, objects and advantages of the invention will become obvious from the description, the drawings and the claims.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to help understanding of the present disclosure, the present disclosure will be described more comprehensively hereinafter with reference to the relevant accompanying drawings.

Referring toFIGS. 1-3, the multi-rotor aircraft1comprises a controller (not shown in the figure), an annular airframe11, at least two first rotor units12and at least two actuation components13. Wherein, the controller is a conventional flight controller in the art, which is arranged on the annular airframe11. The annular airframe11comprises at least two frames111and at least two connecting units112, the adjacent frames111are movably connected by at least one connecting unit112. At least two first rotor units12are arranged on the annular airframe11, that is, the first rotor units12may be arranged on the frame111or on the connecting unit112. The first rotor units12are electrically connected with the controller, and are used to provide lift for the multi-rotor aircraft1to fly. At least two actuation components13are arranged on the annular airframe11, and are electrically connected with the controller. When the multi-rotor aircraft1flies, the actuation components13are used for making the adjacent frames111move away from each other or move close to each other, so as to enlarge or reduce the enclosed area of the annular airframe11respectively.

It can be understood that the multi-rotor aircraft1further comprises a power component (not shown in the figure). The power component is arranged on the annular airframe11and is electrically connected with the controller. The power component is used for providing electric power to the controller, the first rotor unit12and the actuation component13, wherein the power component is a conventional battery module in the art.

Optionally, when the multi-rotor aircraft1flies forward, the thrust of the first rotor unit12is further used to provide driving force for the multi-rotor aircraft1to fly forward.

Further, referring toFIG. 3, in the illustrated implementation, each actuation component13comprises a second rotor unit130and a resilient member (not shown in the figure). Wherein, the second rotor unit130is arranged on the frame111or on the connecting unit112, and is electrically connected with the controller. The second rotor unit130is used for providing driving force to make the adjacent frames111move away from each other, specifically, the thrust of the second rotor unit130is towards the outer side of the annular airframe11or is inclined towards the outer side of the annular airframe11. Two opposite ends of the resilient member are respectively connected to two adjacent frames111, or are respectively connected to the frame111and the connecting unit112connected with the frame111. The resilient force of the resilient member is used for driving the adjacent frames111to move close to each other. In the case that the connecting unit112is extendable, the two opposite ends of the resilient member may be both arranged on the connecting unit112, which provides driving force to make the connecting unit112contract. Preferably, the resilient member is a spring; when the two adjacent frames111are closest, the spring is at its shortest length.

When the second rotor unit130starts and increases thrust, the adjacent frames111move away from each other, so that the distance between the adjacent frames111gradually increases, thereby significantly expanding the enclosed area of the annular airframe11, accordingly, the spring is stretched until the frame111reaches the maximum mechanical displacement relative to the connecting unit112, or until the thrust of the second rotor unit130and the resilient force of the spring are in equilibrium, then the second rotor unit130maintains a certain thrust output to keep the adjacent frames111away from each other, in this case, it can be understood that, the controller may adjust the magnitude of the thrust of the second rotor unit130to keep the adjacent frames away at various distances, enabling the enclosed area of the annular airframe11to be adjusted as various sizes. When the second rotor unit130stops or decreases thrust, the adjacent frames111move close to each other under the action of the resilient force of the spring, so that the distance between the adjacent frames gradually decreases until the enclosed area of the annular airframe11returns to the minimum size, then the resilient force of the spring may be none-zero to keep the adjacent frames111in the closest state. In this way, when the multi-rotor aircraft1flies, the purpose of making the adjacent frames111move away from each other or close to each other can be achieved by means of the second rotor unit130and the resilient member.

The resultant thrust of the whole second rotor units130may be set to be zero, so as to prevent the resultant thrust from affecting the motion control of the multi-rotor aircraft1. Alternatively, the resultant thrust may be set to be non-zero, and may be used for driving the multi-rotor aircraft1to move in a direction same as the resultant thrust or in other specified direction. For example, the resultant thrust is in horizontal direction, while the lift provided by the first rotor units12and the gravity of the multi-rotor aircraft1are in equilibrium, so that the multi-rotor aircraft1can be driven to fly in horizontal direction, which helps to improve the maneuverability of the multi-rotor aircraft1.

It should be noted that, the side at which the enclosed area of the annular airframe is disposed is the inner side of the annular airframe, the side, opposite to the enclosed area, of the annular airframe is the outer side of the annular airframe.

Further, referring toFIG. 2andFIG. 3, in the illustrated implementation, the frame111includes a first frame body1111, a second frame body1112and a connecting portion1113, wherein the first frame body1111and the second frame body1112are connected by the connecting portion1113. The first frame body1111, the second frame body1112and the connecting portion1113may be connected to form U-shaped or L-shaped or V-shaped frame. The first frame body1111of the frame and the second frame body1112of the adjacent frame111are connected by the connecting unit112, that is, the first frame body1111of one of two adjacent frames111is connected with the second frame body1112of the other one of those two frames111by the connecting unit112.

Optionally, the connection unit112may be a linear guide structure, that is, the connection unit112may be a linear guide rail, a guide rod, a guide sleeve or the like, at least one end of the connection unit112is inserted or sleeved with the first frame body1111of the adjacent frame111, or is inserted or sleeved with the second frame body1112of the adjacent frame111. Alternatively, the connecting unit112may be an extendable structure, which is connected to the first frame body1111of one of two adjacent frames111and to the second frame body1112of the other one of those two adjacent frames111, for example, the connecting unit112may be a multi-bar linkage hinge extendable mechanism. Further, the connecting unit112may be a multi-section guide structure or a multi-section extendable structure, that is, the connecting unit112may be a multi-section linear slide rail, a multi-section telescopic sleeve or the like, enabling the adjacent frames111to move away from each other at a larger distance, thereby increasing the variation range of the enclosed area of the annular airframe11.

Optionally, the frame111may slide relative to the connecting unit112which is connected to the first frame body1111of the frame111and slide relative to the connecting unit112which is connected to the second frame body1112of the same frame at the same time, alternatively, the connecting unit112which is connected to the first frame body1111of the frame111and the connecting unit112which is connected to the second frame body1112of the same frame111may extend/contract at the same time.

Further, referring toFIG. 2andFIG. 3, in the illustrated implementation, the first frame body1111is provided with the first rotor unit111arranged on the first frame body1111, and the second frame body1112is provided with the first rotor unit111arranged on the second frame body1112; the connecting portion1113is provided with the second rotor unit130arranged on the connecting portion1113. The second rotor unit130can generate a non-zero component of the thrust along the length direction of the first frame body1111and generate another non-zero component of the thrust along the length direction of the second frame body1112at the same time, wherein the first frame body1111and the second frame body1112are part of the same frame111on which the second rotor unit130is disposed.

Optionally, the first frame body1111and the second frame body1112may be respectively sleeved on the connecting unit112, one second rotor unit130generates a non-zero component of the thrust along the length direction of the first frame body1111of the frame111on which the second rotor unit130is disposed, while another second rotor unit130on the adjacent frame111generates a non-zero component of the thrust along the length direction of the second frame body1112of the frame111on which the second rotor unit130is disposed, the non-zero thrust components of those two second rotor units130are opposite in directions, so as to drive those two frames111to move away from each other. When the second rotor unit130on each frame111of the annular airframe11generates or increases the thrust at the same time, the adjacent frames111move away from each other, thereby enlarging the enclosed area of the annular airframe11.

In another implementation, referring toFIG. 4andFIG. 5, at least one of the first frame body1111and the second frame body1112may be inserted into the connecting unit112, in this case, the first rotor unit12and the second rotor unit130may be arranged on the connecting unit112.

Further, referring toFIG. 3, the thrust of the second rotor unit130may have a non-zero component along the thrust direction of the first rotor unit12. After the second rotor unit130starts, this non-zero thrust component is used for increasing the lift of the multi-rotor aircraft1or increasing the driving force used for driving the multi-rotor aircraft1to fly forward.

Further, referring toFIG. 1toFIG. 3, in the illustrated implementation, the annular airframe11further comprises at least two landing legs14. The landing legs14may be respectively arranged on at least two frames111or at least two connecting units112, which helps the multi-rotor aircraft1land on the ground smoothly.

In order to describe the working principle of the multi-rotor aircraft1, a square annular airframe11is taken as an example. In this example, the annular airframe11comprises four L-shaped frames111and four connecting units112, the corner portion of each L-shaped frame111is provide with one second rotor unit130arranged on the corner portion, each side portion of the L-shaped frame111is provided with one or more first rotor units12arranged on the respective side portion, the resilient member is arranged between two adjacent L-shaped frames111and is connected to those two L-shaped frames. After the multi-rotor aircraft1takes off, the controller controls the four second rotor units130to start and increase the thrust at the same time. Under the action of the thrust of the four second rotor units130, the four L-shaped frames111move away from each other at the same time, thereby enlarging the enclosed area of the annular airframe11. Before the multi-rotor aircraft1lands, the controller controls the four second rotor units130to gradually reduce thrust or to stop at the same time. Under the action of the resilient force of the resilient members, the four L-shaped frames111move close to each other at the same time, thereby reducing the enclosed area of the annular airframe11.

It should be noted that, the annular airframe11is not limited to be square, for example, the annular airframe11may be triangular shaped (as shown inFIG. 6andFIG. 7) or other shapes, which is not limited herein.

It should be noted that the resilient member may be omitted. In one implementation, each actuation component13comprises two groups of second rotor units130, each group of second rotor unit130comprises at least one second rotor unit130, one group of second rotor unit130is used for providing driving force to make the adjacent frames111move away from each other, and the other group of second rotor unit130is used for providing driving force to make the adjacent frames111move close to each other, specifically, the thrust of the other group of second rotor unit130is towards the inner side of the annular airframe11or is inclined towards the inner side of the annular airframe11, so as to provide driving force to make the adjacent frames111move close to each other. When the enclosed area of the annular airframe11needs to be enlarged or to be reduced, one group of second rotor unit130starts or increases the thrust while the other group of second rotor unit130stops or reduces the thrust. For example, when the group of second rotor unit130which is used for providing driving force to make the adjacent frames111move close to each other starts or increases the thrust, and the other group of second rotor unit130stops or decreases the thrust, the enclosed area of the annular airframe11is reduced.

In another implementation, the second rotor unit130is used for providing driving force which makes the adjacent frames111move away from each other. In addition to providing the lift for the multi-rotor aircraft to fly1, the first rotor unit12is further used to provide driving force to make the adjacent frames111move close to each other. Specifically, the thrust of the first rotor unit12acting on the annular airframe11is inclined towards the inner side of the annular airframe11, so that part of the thrust of the first rotor unit12is used for driving the adjacent frames111to move close to each other, meanwhile the first rotor unit12still maintains the non-zero vertical component of the thrust acting on the annular airframe11, which serves as lift used for the multi-rotor aircraft1to fly.

The multi-rotor aircraft1is provided with an annular airframe11, which comprises at least two frames111and at least two connecting units112. The adjacent frames111are driven by the actuation component13to move away from each other or to move close to each other, so as to enlarge or reduce the enclosed area of the annular airframe11respectively. In this way, the multi-rotor aircraft1can actively change the overall size during flight. Specifically, at the take-off stage and at the landing stage, the multi-rotor aircraft reduces the enclosed area of the annular airframe11, which respectively helps the multi-rotor aircraft take off and land in a limited area site. At other stage of the flight, the multi-rotor aircraft1may enlarge the enclosed area of the annular airframe11for some special applications such as catching a drone2intruding into the no-fly airspace, aerial displaying a large advertisement banner, inspecting the structure of a tower-shaped building, etc.

Specifically, in the case that the multi-rotor aircraft1is used for aerial displaying the large advertisement banner, the advertisement banner is arranged on the annular airframe11, the multi-rotor aircraft1deploys the advertisement banner in the air by enlarging the enclosed area of the annular airframe11during flight. In the case that the multi-rotor aircraft1is used for inspecting the tower-shaped building such as a communication tower, a factory chimney tower and a blade of a wind turbine, the inner side of the annular airframe11is surrounded by sensors17(as shown inFIG. 7) used for inspection such as a camera. When performing the inspection, the multi-rotor aircraft1makes the tower-shaped building to penetrate the enclosed area of the annular airframe11, so as to improve the inspection efficiency.

Referring toFIG. 1toFIG. 3, the multi-rotor aircraft in this embodiment is basically the same as that in Embodiment 1. The difference is that, the actuation component13is a linear actuator, two opposite ends of the linear actuator are respectively connected to two adjacent frames111, or are respectively connected to the frame111and the connecting unit112connected with the frame111. In the case that the connecting unit112is extendable structure, the two opposite ends of the linear actuator may be both connected to the connecting unit112. Specifically, the linear actuator is a conventional mechanism that can realize linear motion of the load. The linear actuator may convert the rotary motion of the motor into linear motion of the load by means of a lead screw or a belt transmission; alternatively, the linear actuator may be a pneumatic slide or a hydraulic cylinder, etc. That is, the fixed end of the linear actuator is connected to one of two adjacent frames111, the movable end of the linear actuator is connected to the other one of those two adjacent frames111; alternatively, the fixed end of the linear actuator is connected to one of the frame111and the connecting unit112connected with the frame111, the movable end of the linear actuator is connected to the other one of the frame111and the connecting unit112; alternatively, both the fixed end and the movable end of the linear actuator are connected to the connecting unit112, so that the purpose of making the adjacent frames111move away from each other or close to each other can be achieved.

Referring toFIG. 8toFIG. 10, the multi-rotor aircraft in this embodiment is basically the same as that in Embodiment 1. The difference is that, the actuation component13is connected with the first rotor unit12in a transmission way, and the actuation component13is used for driving the first rotor unit12to change the direction of the thrust acting on the annular airframe11, so as to make the adjacent frames111move away from each other or move close to each other during flight of the multi-rotor aircraft1, thereby enlarging or reducing the enclosed area of the annular airframe11respectively.

Optionally, the actuation component13may comprise an actuation member and a transmission member, the actuation member is arranged on the frame111, one end of the transmission member is connected to the power output shaft of the actuation member, the other end of the transmission member is connected with the first rotor unit12, the actuation member may drive the first rotor unit12to rotate about the power output shaft of the actuation member via the transmission member, so as to change the direction of the thrust of the first rotor unit12acting on the annular airframe11.

Referring toFIG. 9, when the actuation component13drives the first rotor unit12to tilt the thrust acting on the annular airframe11towards the outer side of the annular airframe11at a certain angle, a portion of the thrust of the first rotor unit12is used for driving the adjacent frames111to move away from each other, meanwhile the first rotor unit12still maintains the non-zero vertical component of the thrust acting on the annular airframe11, which serves as lift used for the multi-rotor aircraft1to fly.

Referring toFIG. 8, when the actuation component13drives the first rotor unit12to tilt the thrust acting on the annular airframe11towards the inner side of the annular airframe11at a certain angle, a portion of the thrust of the first rotor unit12is used for driving the adjacent frames111to move close to each other, meanwhile the first rotor unit12still maintains the non-zero vertical component of the thrust acting on the annular airframe11, which serves as lift used for the multi-rotor aircraft1to fly.

In this way, the first rotor unit12can not only provide lift for the multi-rotor aircraft1to fly, but also provide driving force for the annular airframe11to enlarge/reduce the enclosed area.

It should be noted that, when the actuation member drives the first rotor unit12to rotate about the power output shaft of the actuation member, the controller is capable of controlling the first rotor unit12to dynamically change the magnitude of the thrust, making the lift of the multi-rotor aircraft1remain constant, which helps the multi-rotor aircraft1maintain the altitude.

In one implementation, the actuation member is arranged inside the frame111, a guide slot1110may be opened on the frame111, one end of the transmission member extends out from the guide slot1110and is connected with the first rotor unit12, the guide slot1110can guide the transmission member to sway along the cross section of the frame111, and prevent the transmission member from shaking along the length direction of the frame111.

Further, the number of the first rotor units12arranged on each frame111is not limited to one illustrated in the figure, for example, the multi-rotor aircraft comprises two frames111, and the two frames111are each provided with two first rotors12to jointly form a quad-rotor aircraft, the actuation component13arranged on each frame111is used for driving the two first rotors12arranged on the same frame111to synchronously change direction of the thrust acting on the annular airframe11.

Referring toFIG. 11toFIG. 13, the multi-rotor aircraft in this embodiment is basically the same as that in any one of Embodiment 1 to 3. The difference is that, the multi-rotor aircraft1further comprises a net15, the net may be arranged on the frame111or on the connecting unit112or on the landing leg14. The opening of the net15can be scaled up or down along with the enclosed area of the annular airframe11, that is, in the process that the enclosed area of the annular airframe111is enlarged or reduced, the annular airframe111respectively drives the opening of the net15to expand or to shrink at the same time. Optionally, the net15is detachably connected to the frame111or the connecting unit112or the landing leg14, so that the net15may be mounted on the annular airframe11as needed.

Further, the multi-rotor aircraft1is used for catching the drone2intruding into no-fly airspace. Specifically, when the multi-rotor aircraft1needs to catch the drone2, the multi-rotor aircraft1can expand the opening of the net15by enlarging the enclosed area of the annular airframe11, thereby improving the success rate that the drone2enters the net15, and meanwhile keeping the net15in a tensioned state, thus, when the multi-rotor aircraft1flies forward at high speed, a contact between the net15and the first rotor unit12due to shaking of the net15which is caused by air flow can be avoided.

One of implementations that the multi-rotor aircraft1catches the drone2is as shown inFIG. 12, the multi-rotor aircraft1approaches the drone2from behind the drone2, and tilts the annular airframe11in the flight direction, making the drone2finally caught into the net15, which not only enables the first rotor unit12and/or the second rotor unit130to provide driving force for the multi-rotor aircraft1to fly forward, so as to accelerate the multi-rotor aircraft1, but also orientates the opening of the net15towards the drone2, so as to make the drone2caught into the net15once the multi-rotor aircraft1catches up with the drone2. After the drone2enters the net15, the multi-rotor aircraft1can shrink the opening of the net15by reducing the enclosed area of the annular airframe11, thereby lowering the risk that the caught drone2escapes out of the net15via the opening, and meanwhile making the net15slack to trap the caught drone2.

Referring toFIG. 1,FIG. 2,FIG. 3,FIG. 11,FIG. 12andFIG. 13, the multi-rotor aircraft in this embodiment is basically the same as that in Embodiment 4. The difference is that, the frame111is provided with a protective structure16arranged on the frame111; alternatively, the connecting unit112is provided with a protective structure16arranged on the connecting unit112. The protective structure16extends to the inner side of the annular airframe11, and is used for blocking the net15from contacting the propeller of the first rotor unit12. Specifically, the protective structure16is composed of a plurality of protective barriers160. The plurality of the protective barriers are respectively arranged on the frames111or the connecting units112, and are disposed between the propeller of the first rotor unit12and the net15.

When the enclosed area of the annular airframe11is enlarged, the plurality of protective barriers160move away from each other, which avoids blocking the opening of the net15and allows the drone2to enter the net15. When the enclosed area of the annular airframe11is reduced, the plurality of protective barriers160move close to each other, which can partially or completely close the opening of the net15, so as to prevent the caught drone2from escaping out of the net15via the opening of the net15.

The multi-rotor aircraft in this embodiment is basically the same as that in Embodiment 1. The difference is that, the resilient member is replaced with a vectoring mechanism. The vectoring mechanism is electrically connected with the controller, and is connected with the second rotor unit130in a transmission way. The vectoring mechanism is used for driving the second rotor unit130to change the direction of the thrust acting on the annular airframe11, so that, in addition to being used for driving the adjacent frames111to move far away from each other, the second rotor unit130is further used for driving the adjacent frames111to move close to each other.

The method that the vectoring mechanism drives the second rotor unit130to change the direction of the thrust acting on the annular airframe11is substantially the same as the method that the actuation component13drives the first rotor unit130to change the direction of the thrust acting on the annular airframe11in Embodiment 3. However, in this embodiment, the second rotor unit130may only provide driving force for driving the adjacent frames111to move away from each other and to move close to each other, but does not provide lift for the multi-rotor aircraft1to fly. That is, when the thrust of the second rotor unit130acting on the annular airframe11is towards the outer side of the annular airframe11and is perpendicular to the direction of the thrust of the first rotor unit12, the second rotor unit130is only used for driving the adjacent frames111to move away from each other; when the thrust of the second rotor unit130acting on the annular airframe11is towards the inner side of the annular airframe11and is perpendicular to the direction of the thrust of the first rotor unit12, the second rotor unit130is only used for driving the adjacent frames111to move close to each other.

The technical features of the above-mentioned embodiments can be combined. In order to simplify the description, not all possible combinations of the technical features of the above-mentioned embodiments have been provided. It can be appreciated that, as long as no contradiction is concluded from these combinations, all reasonable combinations of the features should be considered as the scope recorded in the description.

The present disclosure mainly presents several embodiments with their descriptions more specific and detailed than others, but they should not be construed as limiting the scope of the present disclosure. It should be noted that for persons skilled in the art, several modifications and improvements can be made without departing from the conception of the present disclosure, which shall all fall within the scope of the present disclosure. Therefore, the scope of the present disclosure shall be subject to the appended claims.