Patent Description:
A drone, which started in the military industry, refers to an airplane or helicopter-shaped vehicle that flies by induction of radio waves without a person riding the drone, and recently the drone has been widely used in military and commercial applications, and research on the drone is also being actively conducted.

However, due to an increasing demand for drones, a landing device capable of accommodating and transporting a plurality of drones at once is required. In this case, the possibility of collision between drones is increasing due to the lack of space to accommodate a plurality of drones.

Accordingly, when accommodating and transporting a plurality of drones, the need for a system capable of preventing collisions between drones and safely accommodating and transporting the plurality of drones is increasing.

<CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT> disclose flying devices.

According to its abstract, <CIT> discloses a variable torque compensator and a robot arm using the same.

The presently claimed invention provides a drone according to appended claim <NUM> and a drone anti-torque compensation method according to appended claim <NUM>.

Example embodiments provide a drone and a drone anti-torque compensation method capable of stabilizing a posture of the falling drone by preventing tumbling that occurs when the drone falls due to a failure in the drone during flight.

Example embodiments provide a drone and a drone anti-torque compensation method capable of inducing a soft landing of the drone by slowing down fall speed when the drone falls due to a failure in the drone during flight.

Example embodiments provide a drone and a drone anti-torque compensation method capable of securing the time required for expansion of a parachute or airbag by slowing down the fall speed when the drone falls due to a failure in the drone during flight.

According to example embodiments, a drone and a drone anti-torque compensation method may maintain hovering by executing the rotation stabilization mode of the drone using the anti-torque compensator.

According to example embodiments, a drone and a drone anti-torque compensation method may stabilize the posture of the falling drone by preventing tumbling that occurs when the drone falls due to a failure in the drone during flight.

According to example embodiments, a drone and a drone anti-torque compensation method may secure, when the drone falls due to a failure in the drone during flight, time required for expansion of a parachute or airbag by slowing down the fall speed.

Effects of a drone and a drone anti-torque compensation method according to an example embodiment are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

These and/or other aspects, features, and advantages of the invention will become apparent and more readily appreciated from the following description of example embodiments, taken in conjunction with the accompanying drawings of which:.

Hereinafter, example embodiments will be described in detail with reference to the accompanying drawings. Various modifications may be made to the example embodiments. Here, the example embodiments are not construed as limited to the disclosure and should be understood to include all changes and replacements which fall within the scope of the claims.

The terminology used herein is for the purpose of describing particular example embodiments only and is not to be limiting of the example embodiments. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components or a combination thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined herein, all terms used herein including technical or scientific terms have the same meanings as those generally understood by one of ordinary skill in the art. Terms defined in dictionaries generally used should be construed to have meanings matching contextual meanings in the related art and are not to be construed as an ideal or excessively formal meaning unless otherwise defined herein.

Hereinafter, example embodiments will be described in detail with reference to the accompanying drawings. When describing the example embodiments with reference to the accompanying drawings, like reference numerals refer to like components and a repeated description related thereto will be omitted. In describing example embodiment, when it is determined that a specific description of a related known technology may unnecessarily obscure the gist of the example embodiments, a detailed description thereof will be omitted.

In addition, although terms of "first," "second," "A," "B," "(a)," "(b)," and the like may be used to explain various components, the components are not limited to such terms. These terms are used only to distinguish one component from another component. When it is mentioned that one component is "connected" or "accessed" to another component, it may be understood that the one component is directly connected or accessed to another component or that still other component is interposed between the two components.

Components included in one example embodiment and components of another example embodiment having a common function will be described using the same name. Unless otherwise stated, descriptions of one example embodiment may be applied to other embodiments as well, and detailed descriptions within the overlapping range will be omitted.

<FIG> illustrates a front view of a drone <NUM> according to a first example embodiment. <FIG> shows an anti-torque compensator of the drone according to the first example embodiment.

The drone <NUM> according to the first example embodiment includes a main body <NUM>, a propulsor <NUM> provided on an outside of the main body <NUM> and configured to generate thrust, and an anti-torque compensator <NUM> configured to compensate for anti-torque of the main body <NUM> generated by the propulsor <NUM>.

The propulsor <NUM> includes a propeller and a motor for driving the propeller. The anti-torque compensator <NUM> maintains constant a yaw-axis angular velocity of the main body <NUM> within a predetermined target range through tilting of the propulsor <NUM>.

In addition, the drone <NUM> according to the first example embodiment further includes a controller <NUM> configured to control driving of the anti-torque compensator <NUM>. When a failure occurs in the propulsor <NUM>, the controller <NUM> maintains constant the yaw axis angular velocity of the main body <NUM> by driving the anti-torque compensator <NUM> to tilt the propulsor <NUM>.

The anti-torque compensator <NUM> of the drone <NUM> according to the first example embodiment includes a fixed joint <NUM> connected to any one of the main body <NUM> or the propulsor <NUM>, a rotation joint <NUM> connected to the other one of the main body <NUM> or the propulsor <NUM>, and a spring <NUM> connecting the fixed joint <NUM> and the rotation joint <NUM>. When the yaw axis angular velocity of the main body <NUM> exceeds a predetermined target value, the controller <NUM> tilts the propulsor <NUM> through the rotation joint <NUM> and the spring <NUM>.

The anti-torque compensator <NUM> further includes a spring extension switch and a spring extension angle stopper. When the controller <NUM> transmit an extension command to the spring extension switch, the spring <NUM> rotates the rotation joint <NUM> to form a tilt angle between the main body <NUM> and the propulsor <NUM>, and a tilt angle of the rotation joint <NUM> is set by the spring extension angle stopper.

The spring <NUM> may include a torsion spring as shown in <FIG>, and tilting of the propulsor may be implemented by the elastic restoring force of the torsion spring according to the extension command of the spring extension switch. For example, the spring <NUM> may be a wire-shaped torsion spring of <FIG> or a plate-shaped torsion spring of <FIG>.

<FIG> is a diagram illustrating a configuration of the propulsor <NUM> and propeller rotation directions of the drone <NUM> according to the first example embodiment. The propulsor <NUM> includes a plurality of propellers. Here, as an example, the propulsor <NUM> may include four propellers <NUM>, <NUM>, <NUM>, and <NUM>.

When a failure occurs in any one of the propellers <NUM>, <NUM>, <NUM>, and <NUM> of the propulsor <NUM>, the controller <NUM> may stop driving of another propeller, which is disposed symmetrically with the propeller in which the failure occurs with respect to the main body <NUM>.

Here, as an example, referring to the perspective view of <FIG>, the drone <NUM> according to the first example embodiment may include four propellers <NUM>, <NUM>, <NUM>, and <NUM> of the propulsor <NUM> spaced apart from each other around the main body <NUM>. As shown in <FIG>, in the four propellers <NUM>, <NUM>, <NUM>, and <NUM> of the propulsor <NUM>, each of the propellers <NUM> and <NUM> in one line symmetry direction rotates in the clockwise (CW) direction, and each of the propellers <NUM> and <NUM> in a different line-symmetric direction may rotate in the counterclockwise (CCW) direction.

<FIG> is a diagram illustrating an operation sequence according to a failure response of the drone <NUM> according to the first example embodiment. <FIG> is a diagram illustrating a response of the propulsor <NUM> according to a failure of the drone <NUM> according to the first example embodiment. <FIG> is a diagram illustrating anti-torque generation according to a failure of the drone <NUM> according to the first example embodiment. <FIG> is a diagram illustrating a response of the anti-torque compensator <NUM> according to a failure of the drone <NUM> according to the first example embodiment. <FIG> is a diagram illustrating a rotation stabilization mode after a failure of the drone <NUM> occurs according to the first example embodiment.

First, the propulsor <NUM> of the drone <NUM> according to the first example embodiment may be operating normally as shown in <FIG>. Here, referring to the perspective view of <FIG>, F is thrust generated by rotation of a single propeller (Force), and T is anti-torque generated by the rotation of the single propeller (Torque). As shown in <FIG>, when all four propellers <NUM>, <NUM>, <NUM>, and <NUM> of the propulsor <NUM> are in normal operation, the total torque may satisfy zero (Ttotal = <NUM>).

At this time, a malfunction of some of the propellers <NUM>, <NUM>, <NUM>, and <NUM> of the propulsor <NUM>, for example the first propeller <NUM> of <FIG>, may occur. A propeller failure may be detected by a sensor mounted on the drone <NUM> detecting a propeller speed, a drone position and posture, and the like.

When a failure of some propellers is detected, the rotation stabilization mode of the drone <NUM> according to the first example embodiment may be started. Hereinafter, the rotation stabilization mode will be described later.

When a failure occurs in the plurality of propellers <NUM>, <NUM>, <NUM>, and <NUM> of the propulsor <NUM>, the controller <NUM> may stop driving of another propeller, which is disposed symmetrically with some propellers having the failure with respect to the main body <NUM>. For example, as shown in <FIG>, the first propeller <NUM> in which a failure occurs may be powered off, and at the same time, another third propeller <NUM> disposed symmetrically with the first propeller <NUM> in which the failure occurs with respect to the main body <NUM> may be powered off to be stopped to drive.

At this time, referring to <FIG>, only the remaining propellers <NUM> and <NUM> other than the third propeller <NUM> disposed symmetrically with the first propeller <NUM> in which the failure occurred may be operating. The remaining propellers <NUM> and <NUM> may be rotationally driven in the same rotational direction(CW), and at this time, the yaw axis angular velocity may continuously increase in the CCW direction by the anti-torque (Ttotal = 2T).

A rotation speed of the yaw axis of the main body <NUM> may be detected and checked by a sensor or the like. Referring to <FIG>, when the rotation speed of the yaw axis of the main body <NUM> increases by more than a target spin rate, the controller <NUM> of the drone <NUM> according to the first example embodiment may transmit an extension command to the anti-torque compensator <NUM> to generate a tilt angle α in the remaining propellers <NUM> and <NUM> of the propulsor <NUM>.

Referring to <FIG>, the compensation torque (2dFsinα) may compensate the anti-torque (2Tcosα) generated by the remaining propellers <NUM> and <NUM> to maintain constantly the yaw axis angular velocity as the target value. Here, the tilt angle α* may be determined by the following equations. <MAT>
<MAT>.

Then, the posture stability of the roll axis and the pitch axis of the main body <NUM> may be checked.

Thereafter, a landing mode of the drone <NUM> according to the first example embodiment may be started to be executed.

As an example of the landing mode, the drone <NUM> in which a failure occurred may be induced to land softly. As shown in <FIG>, the drone <NUM> may maintain a hovering state by maintaining the rotation stabilization mode after a failure occurs. In the simulation for <NUM> sec, the drone <NUM> was able to maintain the hovering state while maintaining the altitude of <NUM>. Thereafter, while the drone <NUM> is switched from the rotation stabilization mode to the landing mode, the controller <NUM> may transmit an altitude command for inducing a soft landing of the drone <NUM>. As shown in <FIG>, in the simulation for <NUM> sec, the drone <NUM> was able to land by stably descending to an altitude of <NUM>. Alternatively, as another example of the landing mode, the drone <NUM> may land with a parachute or an airbag expanded.

As such, the anti-torque compensation method of the drone <NUM> according to an example embodiment includes providing a drone according to the presently claimed invention i.e. according to appended claim <NUM>, detecting, by the controller <NUM>, a failure of the propulsor <NUM>, stabilizing, by controller <NUM>, rotation of the main body <NUM> by blocking power of a part of the propulsor <NUM>, checking, by controller <NUM>, a rotation speed of the yaw axis of the main body <NUM>, and, when the yaw axis angular velocity of the main body <NUM> reaches a target value, driving, by controller <NUM>, the anti-torque compensator <NUM> to maintain constantly the yaw axis angular velocity of the main body <NUM> by tilting the propulsor <NUM>.

The propulsor <NUM> includes a plurality of propellers <NUM>, <NUM>, <NUM>, and <NUM>, and the stabilizing, by the controller <NUM>, of the rotation of the main body <NUM> by blocking the power of the part of the propulsor <NUM> may include, when a failure occurs in any one of the propellers <NUM>, <NUM>, <NUM>, and <NUM> of the plurality of propellers, stopping, by the controller <NUM>, driving of another propeller <NUM>, which is arranged symmetrically with the propeller <NUM> in which the failure occurs with respect to the main body <NUM>.

The driving, by controller <NUM>, of the anti-torque compensator <NUM> when the yaw axis angular velocity of the main body <NUM> reaches a target value may include transmitting, by the controller <NUM>, an extension command to the anti-torque compensator <NUM> to generate tilt angles to the remaining propellers <NUM> and <NUM>, when the yaw axis angular velocity reaches the target value due to the remaining propellers <NUM> and <NUM> other than the propeller <NUM> in which the failure occurs and the other propeller <NUM> that is symmetrically arranged and stopped.

Example embodiments of the drone and the drone anti-torque compensation method are not limited to the first example embodiment of the drone <NUM> described above. Hereinafter, other embodiments will be described, and differences from the drone <NUM> of the first example embodiment will be mainly described.

<FIG> illustrates a schematic front view of a drone <NUM> according to a first example not covered by the presently claimed invention.

Referring to <FIG>, the drone <NUM> according to the first example may include a main body <NUM>, a propulsor <NUM>, and an anti-torque compensator <NUM>, and the anti-torque compensator <NUM> may be disposed within the main body <NUM>. The anti-torque compensator <NUM> may include a rotation joint <NUM> connected to the propulsor <NUM>, a rotation force transmission member <NUM> configured to transmit a rotation force to the rotation joint <NUM>, and a gear box <NUM> connected to the rotation force transmission member <NUM> and disposed in the main body <NUM>. The rotation force is transmitted from the gear box <NUM> to the rotation joint <NUM> through the rotation force transmission member <NUM>, so that the propulsor <NUM> may be tilted.

The gear box <NUM> may be connected to the propulsor <NUM> to tilt the propulsor <NUM>. The gear box <NUM> is a bevel gear type, and may include a ring gear disposed in the main body <NUM>, and a pinion gear engaging with the ring gear and connected to the rotation force transmission member <NUM>.

<FIG> illustrates a schematic front view of a drone <NUM> according to a second example not covered by the presently claimed invention. <FIG> illustrates a schematic front view of a drone <NUM> according to a third example not covered by the presently claimed invention.

In the drone <NUM> according to the second example and the drone <NUM> according to the third example, a motor may be applied instead of a torsion spring.

Referring to <FIG>, the drone <NUM> according to the second example may include a main body <NUM>, a propulsor <NUM>, and an anti-torque compensator <NUM>, and the anti-torque compensator <NUM> may include a fixed joint connected to any one of the main body <NUM> or the propulsor <NUM>, a rotation joint connected to the other one of the main body <NUM> or the propulsor <NUM>, and a motor having a housing fixedly disposed on the fixed joint and a motor shaft connected to the rotation joint. When the yaw-axis angular velocity of the main body <NUM> exceeds a predetermined target value, the controller may tilt the propulsor <NUM> through the motor.

The drone <NUM> according to the second example may precisely adjust the tilt angle by feedback control through a motor. However, a controller may be additionally required for the motor, and a gear box <NUM> may need to be added to implement an example embodiment of the drone <NUM> according to the fourth example embodiment.

Referring to <FIG>, the drone <NUM> according to the third example may include a main body <NUM>, a propulsor <NUM>, and an anti-torque compensator <NUM>, the anti-torque compensator <NUM> may include a rotation joint <NUM> connected to the propulsor <NUM>, a rotation force transmission member <NUM> configured to transmit a rotation force to the rotation joint <NUM>, and a gear box <NUM> connected to the rotation force transmission member <NUM>, the gear box <NUM> may be implemented as a bevel gear type, and the anti-torque compensator <NUM> may include a bevel gear rotation motor in which a rotation shaft is additionally connected to the ring gear.

<FIG> is a diagram illustrating a anti-torque generator <NUM> of a drone <NUM> according to a fourth example. <FIG> is a diagram illustrating a response of the anti-torque generator <NUM> in response to a failure of the drone <NUM> according to the fourth example.

The anti-torque compensator <NUM> may be of a fixed type and configured such that a tilting angle is formed between a main body and a propulsor. As shown in <FIG>, the anti-torque compensator <NUM> may include a fixed joint connected to any one of the main body or the propulsor, and a rotation joint connected to the other one of the main body or the propulsor, and the fixed joint and the rotation joint may be connected and fixed with a tilting angle formed between the propulsor and the main body.

The drone <NUM> according to the fifth example embodiment may generate a null space in which Ttotal=<NUM> by symmetrically applying a tilt angle before the flight. Referring to <FIG>, when the propulsor is driven, in other words, propellers of the propulsor, for example, when all of four propellers <NUM>, <NUM>, <NUM>, and <NUM> are driven, a mating force occurs among the propellers <NUM>, <NUM>, <NUM>, and <NUM> of the propulsor due to the propulsor already forming a tilt angle with respect to the main body. As shown in <FIG>, when the drone <NUM> is viewed from the front, the Fx mating force between the second propeller <NUM> and the fourth propeller <NUM> on the horizontal plane, and a Fy mating force between the first propeller <NUM> and the third propeller <NUM> occur, and equilibrium may be achieved.

Due to this fixed anti-torque compensator <NUM>, in the event of a fall accident, referring to <FIG>, the compensation torque of the remaining propeller may automatically compensate for the anti-torque. In other words, even if the yaw axis is driven by the remaining propeller and rotation of the yaw axis occurs, a compensation torque opposite to the yaw axis rotation direction may be generated. Accordingly, there is no need to additionally provide an extension or driving device. However, it may be necessary to increase the power to generate additional propeller thrust to compensate for loss of the mating force.

As described above, the drone <NUM> according to the presently claimed invention uses an anti-torque compensator to stabilize the posture of the drone even in a fall accident.

The method according to the above-described example embodiments may be recorded in non-transitory computer-readable media including program instructions to implement various operations which may be performed by a computer. The program instructions recorded on the media may be those specially designed and constructed for the purposes of the example embodiments, or they may be of the well-known kind and available to those having skill in the computer software arts. Examples of non-transitory computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM discs and DVDs; magneto-optical media such as optical discs; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like. Examples of program instructions include both machine code, such as code produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations of the above-described example embodiments, or vice versa.

The software may include a computer program, a piece of code, an instruction, or some combination thereof, to independently or collectively instruct or configure the processing device to operate as desired.

Claim 1:
A drone comprising:
a main body (<NUM>, <NUM>, <NUM>, <NUM>);
a propulsor (<NUM>, <NUM>, <NUM>, <NUM>) provided on an outside of the main body and configured to generate thrust, wherein the propulsor comprises a plurality of propellers; and
an anti-torque compensator (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) configured to compensate for anti-torque of the main body generated by the propulsor when a failure occurs in the propulsor,
wherein the anti-torque compensator is configured to maintain constant a yaw axis angular velocity of the main body within a predetermined target range through tilting of the propulsor, the drone (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) further comprising:
a controller (<NUM>) configured to control driving of the anti-torque compensator,
wherein, when the failure occurs in the propulsor, the controller is configured to drive the anti-torque compensator to tilt the propulsor to maintain constant the yaw axis angular velocity of the main body,
wherein the anti-torque compensator comprises:
a fixed joint (<NUM>) connected to any one of the main body or the propulsor;
a rotation joint (<NUM>, <NUM>, <NUM>) connected to the other one of the main body or the propulsor;
characterized in that the anti-torque compensator comprises:
a spring (<NUM>) configured to connect the fixed joint and the rotation joint, in that
the controller is configured to tilt the propulsor through the rotation j oint and the spring when the yaw axis angular velocity of the main body exceeds a predetermined target value, further characterized in that the anti-torque compensator further comprises:
a spring extension switch; and
a spring extension angle stopper, and in that
when the controller transmits an extension command to the spring extension switch, the spring is configured to rotate the rotation j oint to form a tilt angle between the main body and the propulsor, and the tilt angle of the rotation joint is set by the spring extension angle stopper.