WO2018032425A1

WO2018032425A1 - Unmanned aerial vehicle, and unmanned aerial vehicle stability control method and control device

Info

Publication number: WO2018032425A1
Application number: PCT/CN2016/095723
Authority: WO
Inventors: 瞿宗耀; 吴韬
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2016-08-17
Filing date: 2016-08-17
Publication date: 2018-02-22
Also published as: CN107624171B; CN107624171A

Abstract

An unmanned aerial vehicle (1), comprising: a central portion (10); and a plurality of mechanical arms (20) extending outwards from the central portion (10), at least one power device (30) provided on each of the mechanical arms (20), wherein the power device (30) is used to move the unmanned aerial vehicle (1). A state of at least one of the mechanical arm (20) and the power device (30) provided thereon can be adjusted according to a change in a center of gravity of the unmanned aerial vehicle (1). Further provided is a stability control device and stability control method for the unmanned aerial vehicle (1).

Description

UAV and control method and control device for controlling the attitude of drone

Technical field

The invention relates to a drone, in particular to a drone capable of controlling its posture and a control method and a control device for controlling the posture of the drone.

Background technique

The drone generally includes a fuselage and a plurality of arms extending outward from the fuselage, and the arm is provided with one or more rotor blades away from the end of the fuselage, and the rotation of the rotor blades can drive the drone to fly. In a drone having a plurality of rotors such as an unmanned aerial vehicle, a posture such as movement or rotation of the drone is maintained by controlling the rotational speed of the rotor. When the drone equipped with equipment such as universal joints operates, the position of the center of gravity of the drone changes. Therefore, the attitude of the drone is maintained by controlling the rotational speed of each of the rotors provided on the drone.

However, there is an upper limit to the performance of the motor used to rotate the rotor or the current flowing from the driver that controls the motor. Therefore, when the center of gravity of the drone has a large change, the attitude of the drone will also change greatly. In order to overcome such a change in attitude, a higher current output is required. There may be cases where the attitude of the drone cannot be properly maintained.

Summary of the invention

In view of this, it is necessary to provide a drone that can properly maintain the attitude of the drone, its attitude control device, and a control method.

A drone comprising a central portion; a plurality of arms extending outwardly from the central portion; and at least one power device disposed on each of the arms, the power device for moving the The state of at least one of the manipulator, the arm and the power unit disposed thereon can be changed according to a change in the center of gravity of the drone.

A UAV attitude control method includes: determining a change in a center of gravity of the drone; and changing a state of at least one of a power device disposed on the arm and the arm to counteract a change in a center of gravity of the drone .

A control device for controlling a posture of a drone, the control device comprising a gravity center control portion, wherein the gravity center control portion is configured to change according to a gravity center of the drone when a gravity center of the drone changes Determining the change in state of the power unit provided on one or more of the arms or arms.

The above-mentioned drone and its attitude control method and attitude control device change the state of the power device provided on the arm or the arm when the center of gravity of the drone changes to counter the change of the center of gravity, avoiding only The use of rotor speed adjustment to maintain the speed limit of the drone attitude.

DRAWINGS

1 is a perspective view of a drone according to an embodiment of the present invention.

2 to 5 are perspective views of a drone with a load according to an embodiment of the present invention.

Fig. 6 is a flow chart showing a method of controlling the attitude of a drone according to an embodiment of the present invention.

7 through 10 are schematic views of adjusting the distance of the rotor blade axis to the center of the drone according to an embodiment of the present invention.

Fig. 11 is a partial functional block diagram of a drone according to an embodiment of the present invention.

Figure 12 is a schematic view of a carrier of a drone according to an embodiment of the present invention.

Main component symbol description

Drone 1

Central Department 10

Main control unit 11

Storage device 12

Rotor control unit 13

Communication module 14

Sensor 15

Arm control unit 16

Center of gravity control unit 17

Center of gravity determination unit 170

Arm selection unit 172

Arm length determining unit 174

Configuration determination section 176

Arm 20

Power unit 30

Motor 32

Rotor 34

Carrier 40

Carrier control unit 41

Drive 42

Drive motor 43

Support mechanism 44

Camera assembly 50

Prism assembly 51

Prism 510

Prism control unit 512

Shooting component 52

Shooting component 520

Shooting control unit 522

Memory 524

Center of gravity position adjustment unit 526

The invention will be further illustrated by the following detailed description in conjunction with the accompanying drawings.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

It should be noted that when a component is referred to as being "fixed" to another component, it can be directly on the other component or the component can be present. When a component is considered to "connect" another component, it can be directly connected to another component or possibly a central component. When a component is considered to be "set to" another component, it can be placed directly on another component or possibly with a centered component. The terms "vertical," "horizontal," "left," "right," and the like, as used herein, are for illustrative purposes only.

All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. The terminology used in the description of the present invention is for the purpose of describing particular embodiments and is not intended to limit the invention. This article The term "and/or" used includes any and all combinations of one or more of the associated listed items.

The present invention provides a drone that can be used in any suitable environment, such as in the air (eg, a rotorcraft, a fixed-wing aircraft, or a fixed-wing and rotor-mixed aircraft), in water (eg, a ship or submarine) ), on the ground (eg, motorcycles, cars, trucks, buses, trains, etc.), in space (eg, space shuttle, satellite or detector), or underground (eg subway), or any of the above environments combination. In this embodiment, the drone is a rotorcraft, wherein the rotors may be a single rotor, a double rotor, a triple rotor, a quadrotor, a six-rotor, and an eight-rotor. For convenience of description, the drone in the following embodiment is described by taking a quadrotor as an example.

Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. The features of the embodiments and examples described below can be combined with each other without conflict.

Referring to FIG. 1 , the drone 1 includes a center portion 10 , a plurality of arms 20 extending outward from the center portion 10 , and a power unit 30 disposed on the arm 20 . The power unit 30 is used to move the drone 1 . One end of each arm 20 connected to the body 10 is a proximal end portion of the arm 20, and the other end facing away from the proximal end is a distal end portion of the arm 20. In the present embodiment, a distal end portion of each arm 20 is provided with a power unit 30, and the power unit 30 includes a motor 32 and a rotor 34 that is driven to rotate by the motor. The rotation of the rotor 34 drives the movement of the drone 1. The movement may include takeoff, landing, hovering, and movement in the air with respect to three translational degrees of freedom and three degrees of rotational freedom. In some embodiments, the powerplant 30 can include one or more rotors 34. The rotor 34 can include one or more rotor blades coupled to a rotating shaft. The rotor blade or shaft can be rotated by the motor. Although the power unit 30 of the drone 1 is described as including four rotors 34 in the embodiment, other suitable numbers, types, or arrangements of the power unit 30 are implementable. For example, the rotors 34 can be one, two, three, four, five, six, seven, eight or more. The rotor 34 can be disposed horizontally, vertically, or at any suitable angle relative to the drone 1. The angle of the rotor may be fixed or variable. The distance between the oppositely disposed rotor shafts may be any suitable distance, such as less than or equal to 2 meters, or less than or equal to 5 meters. Alternatively, the distance may be between 40 cm and 1 meter, between 10 cm and 2 meters, or between 5 cm and 5 meters. The motor 32 can be a DC motor (for example: a brush motor or a brushless motor) or an AC motor. In some embodiments, the electric machine 32 can be assembled to drive a rotor blade.

In some embodiments, the drone 1 may further include a carrier 40 for carrying a load, and the carrier 40 may be a carrier mechanism such as a gimbal or the like that is rotatable about the central portion about one or more axes. For example, a carrier mechanism that is rotatable relative to the central portion 10 about a pitch axis and a roll axis as shown in FIG. The carrier mechanism is used to carry a functional load or a non-functional load. The functional load may be a load for performing a particular function, such as a sensor, transmitter, tool, instrument, manipulator, or other functional device. In the embodiment shown in FIG. 1, the load is a camera assembly 50. In some scenarios, the camera assembly 50 can be a camera located below the central portion 10. Through the carrier mechanism 10, the camera can be rotated about the central portion 10 about one or more axes to capture images of multiple viewing angles.

A control system (e.g., a flight control system) may be disposed on the center portion 10 to control the flight of the drone 1. In some embodiments, the control system is based on one or more of: the location of the drone 1, the orientation of the drone 1, the current state of the drone 1, time or said The acquired data is sensed by the sensor or load of the drone 1 to control the operation of the drone 1.

Alternatively or in combination, the control system may include a receiver or other communication module disposed on the drone 1 for receiving user instructions, such as receiving user instructions from a remote terminal. The user command received by the receiver is used to control the power unit 30, which is used to drive the drone to operate, such as take off, fly, hover or land, and the like.

In some embodiments, the drone 1 can carry a variety of different loads (eg, cleaning tools, fishing nets, picking tools, or cutting tools, etc.) through the accessory arm, and during load operation (eg, extending outward from the folded state) There may be a change in the center of gravity of the drone 1 .

Referring to FIG. 2 to FIG. 5, an exemplary unmanned aerial vehicle 1 with an auxiliary arm is used as a functional device (for example, the cleaning tool in FIG. 2, the fishing net in FIG. 3, The grasping tool of FIG. 4, the cutting tool of FIG. 5), when the functional device is extended outward from the carrier, the center of gravity of the drone 1 changes, possibly causing the attitude of the drone 1 A change occurs, such as tilting in the direction in which the functional device is extended. In order to avoid a change in the posture of the drone 1, it is necessary to increase the rotational speed of the rotor provided in the same direction as the extending direction of the functional device. However, the rotor speed is limited by an upper limit. Therefore, in order to prevent the rotor speed from reaching the upper limit, the posture of the drone 1 cannot be maintained, and the machine can be extended in the extending direction of the functional device. The distance from the axis of the rotor blade on the arm to the center of the drone or the distance from the axis of the rotor blade on the arm provided in the opposite direction of the direction in which the functional device is extended to the center of the drone.

When controlling the drone, the flight controller extracts the state parameter values of the unmanned aerial vehicle such as angular velocity, acceleration, direction and position from an inertial sensor (IMU), an accelerometer, a magnetometer and a GPS receiver. The rotational speed ω of each rotor controls the frame to reach a target attitude and a target speed.

How to calculate the rotor speed ω according to the obtained parameter values is part of the exclusive law of different companies, but the input and output are similar. The input is the state parameter value of the drone, including angular velocity, acceleration, direction and position, and the output is the rotational speed ω of the rotor. The calculation result of the present invention can output the length l of the arm in addition to the rotational speed ω of the rotor, wherein the length of the arm refers to the axis of the blade of the rotor provided on the arm to the drone. The distance of the center.

Assuming that the world coordinate system (World Coordinate) is W(x, y, z) and the UAV body coordinate system is B(x, y, z), the transformation matrix R(Φ, Θ, Ψ) of the two coordinate systems is satisfied.

Where Φ is the roll angle of the drone along the X axis; Θ is the pitch angle of the drone along the Y axis; Ψ is the yaw angle of the drone along the Z axis.

According to the coordinate system conversion matrix R, the basic dynamic formula of the drone can be obtained as follows:

Where k _m is the coefficient between the rotor output force and the rotational speed ω; k _d is the coefficient between the rotor output torque and the rotational speed ω; l ₁ ～ l ₄ is the distance from the rotor blade axis to the center of the drone. l _x , l _y , l _z are inertia along the X, Y, and Z axes.

Please refer to FIG. 6, which is a flowchart of a method for controlling the attitude of a drone according to an embodiment of the present invention.

Step 70: The controller of the drone acquires a drone state parameter. The state parameters include, but are not limited to, angular speed, direction, position, etc. of the drone. The status parameter of the drone may be derived from one or more sensors disposed on the drone. The one or more sensors may sense the spatial orientation, velocity, and/or acceleration of the drone 10 (eg, relative three-dimensional translational degrees of freedom and three-dimensional rotational degrees of freedom). The one or more sensors may include, but are not limited to, a Global Positioning System (GPS) sensor, a motion sensor, an inertial sensor, a gyroscope, an accelerometer, a magnetometer, a proximity sensor, or an image sensor. The data sensed by the one or more sensors can be used to control the flight of the aircraft (eg, spatial orientation, velocity, and/or direction). In some embodiments, the one or more sensors may also be used to provide information about the surrounding environment of the aircraft, such as weather conditions, proximity to potential obstacles, location of geographic features, location of artificial structures, and the like. Things. The one or more sensors may be disposed on a central portion of the drone or on a carrier or load.

In step 72, the controller of the drone calculates the rotational speed ω _i (i=1, 2, 3, 4) of each rotor according to the formula (1) and the received state parameters.

Step 74: The controller of the drone determines whether the rotational speed ω _{i of} the rotor is greater than a predetermined limit rotational speed value ω _t . The selection of the limit speed value ω _t depends on the characteristics of one or more electronic components of the drone, such as the current flowing through the one or more electronic components. In some embodiments, the limit speed value ω _t is determined to avoid placing an additional burden on the one or more electronic components. For example, the limit speed value ω _{t is} selected to ensure that the current of the rotor is below a maximum current limit. In some embodiments, the highest current limit value may be that one or more components of the UAV may be destroyed when the highest current limit value is exceeded. In some embodiments, the determination of the limit speed value ω _t requires consideration of the energy consumption of the battery. In some embodiments, the limit speed value ω _t may be set to about 500 rpm. In other embodiments, the limit speed value ω _t may also be set to be greater than or less than 500 rpm. If it is greater than the predetermined limit rotational speed value ω _t , the flow proceeds to step 76, otherwise, the flow proceeds to step 78.

In step 76, the controller of the drone sets the ω _i =ω _t .

Step 78, the controller of the drone calculates the distance l _i (i=1, 2, the axis of each rotor blade to the center of the drone according to the value of ω _i and the formula (2). 3, 4).

In step 710, the controller of the drone adjusts the rotational speed of the corresponding rotor and the distance of the axis of the rotor blade to the center of the drone based on the calculated values of ω _i and l _i . Specifically, when the current rotor rotational speed is set to the calculated rotational speed ω _i , ω _i = ω _t , the distance from the axis of the current rotor blade to the center of the drone is set to the calculated l _i ; if ω _i < ω _t keeps the distance of the current rotor blade axis from the center of the drone unchanged.

Changing the axis of the rotor blade on the arm to the center of the drone can be by linearly stretching or contracting the arm, folding the arm at a designated position on the arm, changing the position The position of the rotor on the arm or the angle of the rotor relative to the arm is achieved.

In the flowchart, before step 70, a step of sensing a change in the center of gravity of the drone may also be included. When the change in the center of gravity of the drone is due to a change in the configuration (ie, state) of the load, the configuration change of the load can be obtained by a sensor disposed on the load or disposed on a carrier carrying the load. In the embodiment shown in FIG. 2 to FIG. 5, when the functional device is extended outward from the carrier, a sensor disposed on the functional device or a sensor disposed on the carrier may acquire the The configuration of the functional device is changed to determine that the center of gravity of the drone has changed. In some embodiments, the change in configuration/status of the load includes, but is not limited to, linearly expanding, rotating, folding, installing, disassembling the load relative to a central portion of the drone.

It can be understood that the sensing of the offset of the center of gravity of the drone can also be determined based on the state parameters of the drone.

Please refer to FIG. 7 to FIG. 10, which are schematic diagrams showing changes in the distance from the axis of the rotor blade provided on the arm of the UAV to the center of the UAV. For example, in FIG. 7, the distance of the axis of the rotor blade of the rotor blade 34 to the center of the drone when the arm 20 linearly expands or contracts in the direction in which the arm extends (in the direction of the arrow in the figure) l _i is equal to the length d of the arm 20 (i.e., the distance from the position A of the rotor 34 to the center point O of the center portion 10; i is a positive integer representing the number of the arm) change. When the arm 20 linearly extends away from the central portion 10, the length d of the arm 20 becomes longer, that is, the axis of the rotor blade of the rotor 34 disposed on the arm to the unmanned The distance l _{i of the} machine center becomes longer; conversely, when the arm 20 linearly contracts toward the center portion 10, the length d of the arm 20 becomes shorter, that is, the rotor provided on the arm The distance l _i from the axis of the rotor blade of 34 to the center of the drone becomes shorter. The length of the arm that should be contracted or extended can be determined based on the determined l _i and the current length d of the arm. At least one of the arm 20 and the center portion 10 may be provided with a drive mechanism that drives the arm 20 to linearly expand or contract. The drive mechanism may include a motor and a meshing gear that drives the meshing gear by rotation of the motor such that the arm 20 linearly expands and contracts.

In Figure 8, the arm 20 can be folded at a designated point B to vary the distance l _i of the axis of the rotor blade of the rotor 34 to the center of the drone. The angle of folding is α, d1+d2=d, from which it can be seen that the smaller the angle α of the folding, the smaller the angle α of the folding, the axis of the rotor blade of the rotor 34 to the center of the drone. The distance l _{i is} smaller. The angle α of the fold can be calculated from the determined l _i and the known d1, d2. It can be understood that the specified folding points are not limited to one, and may be two or more. The folding of the arm 20 can be achieved by a drive mechanism provided on the central portion 10 or the arm 20.

In Fig. 9, the position of the rotor 34 disposed on the arm 20 can be changed, and can be changed along the extending direction of the arm (in the direction of the arrow in the figure), thereby changing the axis of the rotor blade of the rotor 34. The distance l _i to the center of the drone. Changing the position of the rotor on the arm is similar to the effect of extending or contracting the arm, and the distance d between the rotor and the center point of the drone, that is, the rotor blade of the rotor 34, may be changed. The distance from the axis to the center of the drone l _i . A sliding slot may be disposed on the arm 20, and the rotor 34 is slidably disposed on the arm 20, and the rotating wing 34 is driven by a driving mechanism disposed on the arm 20 or the rotor fixing seat. The arm 20 slides to change the distance l _i of the axis of the rotor blade of the rotor 34 to the center of the drone.

In FIG. 10, the rotor 34 disposed on the arm 20 is rotated relative to the arm 20 such that the angle β between the axis of the blade of the rotor 34 and the arm 20 is changed, and the smaller β, The smaller the distance l _i from the axis of the rotor blade of the rotor 34 to the center of the drone, and vice versa. The distance from the rotor setting position to the center point O of the central portion 10 is d, and the angle β can be determined by sinβ=l _i /d.

In some embodiments, the method for adjusting the distance l _i of the axis of the rotor blade of the rotor to the center of the drone described in FIG. 7 to FIG. 10 may be used alone or in combination, for example, by using a machine. The linear telescoping of the arm is combined with the rotation of the rotor to adjust the distance l _i of the axis of the rotor blade of the rotor to the center of the drone.

The change in the distance l _i from the axis of the rotor blade to the center of the drone is achieved during flight. In some embodiments, a change in the distance l _i of the axis of the rotor blade to the center of the drone may also occur prior to flight of the drone. When the drone is docked on a surface (such as the ground) before flight, the configuration of increasing or decreasing the load of the drone and changing the load of the drone may cause the center of gravity of the drone In order to ensure the balance of the drone during take-off, the distance l _i of the axis of the rotor blade of one or more arms of the drone to the center of the drone can be adjusted in advance. In this case, the connection or removal of the load or the change in the state of the load may be sensed by one or more sensors disposed on the drone, and then the unmanned person is calculated via the change Offset direction and offset of the center of gravity of the machine, and then calculating the axis of the rotor blade of one or more arms to the center of the drone according to the offset direction and the offset of the center of gravity of the drone Distance l _i . The calculation method is similar to the method in the above flight process, and will not be described again.

Please refer to FIG. 11 , which is a partial functional block diagram of a drone according to an embodiment of the invention. The drone 1 includes a main control unit 11, a storage device 12, a rotor control unit 13, a communication module 14, a sensor 15, a arm control unit 16, and a center of gravity control unit 17.

The main control unit 11 may include one or more processors, such as a programmable processor (for example, a central processing unit (CPU). The main control unit 11 is operatively connected to the storage device 12, the rotor One or more of the control unit 13, the communication module 14, the sensor 15, the arm control unit 16, and the center of gravity control unit 17. The storage device 12 may be a non-transitory computer readable medium. The computer readable medium can store logic, code, and/or program instructions of one or more steps executable by the processor. The non-transitory computer readable medium can include one or more memory units (eg, Removable medium or an external memory such as an SD card or random access memory (RAM). In some embodiments, the storage device 12 can be used to store processing results generated by the processing unit.

The rotor control unit 13 is for controlling the state of the drone 1 under the control of the main control unit 11. For example, the rotor control portion 13 can be used to control the power mechanism 30 of the drone 1 to adjust the orientation, velocity, and/or acceleration of the six-dimensional degrees of freedom of the drone 1 .

The communication module 14 is configured to transmit and/or receive data from one or more external devices (eg, a terminal, display device, or other remote controller). Any suitable means of communication may be employed, such as wired communication or wireless communication. For example, the communication module 14 can utilize one or more of a local area network (LAN), a wide area network (WAN), infrared, radio frequency, WiFi, point-to-point (P2P) networks, telecommunications networks, cloud communications, and other similar communication networks. Alternatively, a repeater station such as a tower, satellite or mobile workstation can be employed. Wireless communication can be distance-based or distance-independent. In some embodiments, the communication needs to be visible or not. The communication module 14 can transmit the processing result generated by the main control unit 11, predetermined control data, and receive a control command from a terminal or a remote controller.

In some cases, control commands from the terminal or remote controller may include relative position, movement, actuation, or control of the drone 1, carrier 40, and load. For example, the control command may change the position and/or direction of the drone 1 (eg, by controlling the power unit 30) or cause the load to move relative to the drone 1 (eg, by control) The carrier 40). Control commands from the terminal or remote controller can control the load, such as controlling the operation of a camera or other functional device (eg, acquiring a still or moving image, zooming in or zooming out the lens, turning it on or off, switching the image mode, Change the image resolution, focus, change the depth of field, change the exposure time, change the angle of view or field of view; stretch or shrink the functional device). In some cases, communication information from the drone 1, carrier 40, and load may include information from one or more sensors 15. The communication may include information sensed by one or more different types of sensors (eg, a GPS sensor, a motion sensor, an inertial sensor, a proximity sensor, or an image sensor). The information may be information about the orientation (eg, position, direction), movement or acceleration of the aircraft, carrier, and/or load. The load-derived information may include the load-sensed data or the sensed state of the load. The control commands provided and transmitted by the terminal or remote controller can be used to control the status of one or more of the drone 1, carrier 40, and load. Alternatively or in combination, the carrier 40 and the load may also respectively include a communication module in communication with the terminal or remote controller such that the terminal or remote controller may independently and the drone 1 , carrier 40, and load for communication and control.

The sensor 15 can include various types of sensors that can collect information about the drone 1 in a variety of different ways. A variety of different types of sensors can sense different types of signals or signals from different sources. For example, the sensor may include an inertial sensor, a GPS sensor, a proximity sensor (eg, a laser sensor), or a visual/image sensor (eg, a camera). In some embodiments, the sensor 15 is operatively coupled to a communication module (eg, a Wi-Fi transmission module) that can be used to directly transmit sensed data to a suitable external device or system.

The arm control unit 16 is configured to control the movement of the arm 20 relative to the central portion 10 under the control of the main control unit 11, including, but not limited to, linear stretching or contraction, folding, rotation, and the like. Thereby, the power unit 30 mounted on the arm 20 is moved relative to the center portion 10.

The center of gravity control unit 17 is configured to determine the state of one or more arms or the state change of the power unit provided on the arm according to the center change of the drone when the center of gravity of the drone changes. The central control unit 17 may be disposed in the central portion 10 of the drone 1 as part of the flight control system of the drone 1 or as a controller independent of the flight control system. The gravity center control unit may include a processor and a series of instruction codes executable by the processor, and the functions of the gravity center control unit 17 are implemented by the processor executing the series of instruction codes. Specifically, the center of gravity control unit 17 is configured to determine an arm of the UAV that is in a state of being changed against the center of gravity offset when the center of gravity of the UAV is offset or offset, and to determine the selected arm. The distance from the axis of the rotor blade of the power unit to the center of the drone, and the state changes that need to be made. The state change (also referred to as configuration change) includes, but is not limited to, linear extension and contraction of the arm, folding of the arm, linear movement or rotation of the rotor provided on the arm relative to the arm (see Figure 7- One or more of 10).

The gravity center control unit 17 includes a gravity center determination unit 170, an arm selection unit 172, an arm length determination unit 174, and an arrangement determination unit 176. The center of gravity determining unit 170 is configured to determine the offset of the center of gravity of the drone 1 . The arm selection unit 172 is configured to determine an arm that needs to be changed in accordance with the offset of the center of gravity. For example, when the center of gravity is shifted to one side, the length of the arm provided in the direction in which the center of gravity is shifted may be extended or the length of the arm provided in the opposite direction to the direction of the center of gravity offset may be shortened. The arm length determining portion 174 is for determining the distance from the axis of the rotor blade provided on the arm to the center of the drone based on the offset of the center of gravity. The arm length determining method is referred to the flow method. The configuration determining unit 176 is configured to determine a state change that needs to be made based on the arm length determined by the arm length determining unit 176. The state change may include one or more of the methods of varying the distance of the axis of the rotor blade to the center of the drone as described in Figures 7-10.

In the above embodiment, the determination of the offset of the center of gravity can be achieved by sensing the change in the state of the load. For example, in the embodiment illustrated in Figures 2 through 5, the drone 1 includes an accessory arm that can be sensed by a sensor disposed on the accessory arm to sense the offset of the center of gravity. In other embodiments, the offset of the center of gravity may also be determined by sensing a change in state of the load by a sensor disposed on the carrier or load. In some embodiments, the offset of the center of gravity may be adjusted by using the above-described change of the state of the arm and the rotor provided thereon to adjust the attitude change caused by the balance center of gravity shift, and the adjustment load or the carrier relative position may also be used. The position of the center Set to achieve the adjustment of the center of gravity.

For example, in Figure 11, the drone is coupled to a carrier 40 on which one or more loads can be carried. The carrier 40 may include a carrier control portion 41, a driver 42, a drive motor 43, and a support mechanism 44. The carrier control unit 41 controls the carrier to rotate about the yaw axis, the pitch axis, and the roll axis under the control of the main control unit 11. Correspondingly, the drivers 42 respectively include a yaw axis drive, a pitch axis drive and a roll axis drive; the drive motor 43 includes a yaw axis drive motor, a pitch axis drive motor and a roll axis drive motor. The support mechanism 44 includes a yaw axis rotation mechanism, a pitch axis rotation mechanism, and a roll axis rotation mechanism.

In the embodiment shown in FIG. 11, only one type of load is shown: camera assembly 50. The camera assembly 50 includes a prism assembly 51 and a photographing assembly 52. The prism assembly 51 includes a plurality of prisms 510 and a prism control unit 512. The imaging unit 52 includes an imaging element 520 and an imaging control unit 522. The imaging control unit 522 is configured to control the imaging element 520 to perform imaging under the control of the main control unit 11. In some embodiments, the photographing component 52 can also include a memory 524, which can be a removable memory card or a removable storage disc for storing images captured by the photographing element 520. In some embodiments, the imaging element 526 may further include a center of gravity position adjustment portion 526 for adjusting the center of gravity of the camera assembly under the control of the imaging control portion 522.

In some embodiments, the load or the carrier carrying the load is provided with a sensor capable of sensing a predetermined change in the state of the load, and when a predetermined change occurs in the state of the load, The center of gravity of the drone changes when a state of the load changes (a portion of the load moves away from or near the center of the drone in a direction away from the center of gravity of the drone, such as FIG. 2 - in the embodiment shown in Figure 5, the carrier control portion controls the carrier relative to the center when a portion of the functional device projects away from the central portion 10, causing the center of gravity of the drone to change The portion rotates to adjust the center of gravity of the drone to keep the drone in balance.

Referring to FIG. 12, it is a schematic diagram of an exemplary carrier 6 that can adjust the center of gravity of the drone by controlling the carrier or load. In this embodiment, the center of gravity of the drone coincides with the direction of the center of gravity of the carrier 6. The carrier 6 includes a base 60, a fixing member 61, and a movable member 62. The fixing member 61 is connected to the center portion of the drone through the base 60. The fixing member 61 is substantially spherical, and the movable member 62 is a frame that is disposed on the outer surface of the ball, and the frame is Can carry one or more loads. The movable member 62 is rotatable relative to the fixed member 61 about the pitch axis 63-2 and the roll shaft 63-3, thereby causing one or more loads carried thereon to rotate. The base 60 is rotatable relative to the drone about the yaw axis 63-1. When the state of one or more loads disposed on the movable member 62 changes, causing the center of gravity of the carrier 6 to deviate from the center of the sphere, the movable member 62 can be wound around the pitch axis 63-2 or the roll axis 63-3 is rotated such that the center of gravity of the carrier returns to the center of the sphere. The offset of the center of gravity of the carrier may be sensed by the sensor 64-1 disposed on the base 60 to sense the degree of rotation of the carrier about the yaw axis and one or both of the movable members 62 A plurality of sensors, such as sensors 64-2, 64-3, sense the extent to which the movable member 62 is rotationally rotated about the pitch axis 63-2 or the roll axis 63-3, and determine the degree of rotation according to the sensed degree of rotation. The offset of the center of gravity of the carrier.

In addition, those skilled in the art can make various other changes and modifications in accordance with the technical concept of the present invention, and all such changes and modifications are within the scope of the claims of the present invention.

Claims

A drone comprising a central portion; a plurality of arms extending outwardly from the central portion; and at least one power device disposed on each of the arms, the power device for moving the The human machine is characterized in that the state of at least one of the arm and the power device disposed thereon can be changed according to a change in the center of gravity of the drone.
The drone of claim 1 wherein said power unit includes a rotor blade that changes the axis of the rotor blade of the power unit disposed on one or more of said arms to said drone The distance of the center point is against the change in the center of gravity of the drone to maintain the attitude of the drone, wherein the center point of the drone is the center of gravity when the drone is in balance.
The drone according to claim 2, wherein the change in the distance of the axis of the rotor blade disposed thereon to the center of the drone is achieved by changing the state of one or more of said arms.
The drone of claim 3 wherein the change in state of the arm comprises linear extension or contraction of the arm in the direction of extension of the arm.
A drone according to claim 4, wherein when said center of gravity of said drone is changed, said change in said arm state includes linearly extending said center of gravity offset direction away from said central portion The arm provided above or the arm disposed in the opposite direction to the direction in which the center of gravity is offset is linearly contracted toward the center portion.
The drone according to claim 4, wherein the extent to which the arm extends or contracts is determined according to the offset of the center of gravity of the drone.
The drone of claim 3 wherein the change in state of the arm includes folding of the arm at at least one designated point on the arm.
The drone according to claim 7, wherein when the center of gravity of the drone is changed, the change in the state of the arm includes folding an arm provided in a direction opposite to a direction in which the center of gravity is shifted.
The drone according to claim 7, wherein the degree of folding of said arm is determined according to an offset of a center of gravity of said drone.
A drone according to claim 2, wherein the distance of the axis of the rotor blade to the center of the drone is achieved by changing the state of the power unit provided on one or more of said arms change.
The drone of claim 10 wherein the change in state of the power unit disposed on said arm includes changing the position of its rotor blade on the corresponding arm.
The drone according to claim 11, wherein when the center of gravity of the drone is changed, the change in the state of the power unit includes linearly moving the center of gravity offset direction away from the center portion The rotor blades on the upper arm provided or the rotor blades on the arm disposed in the opposite direction to the direction in which the center of gravity is shifted are linearly moved toward the center portion.
The drone according to claim 11, wherein the position of said rotor blade on the corresponding arm is determined based on said center of gravity offset.
The drone of claim 10 wherein the change in state of the power unit disposed on the arm includes rotation of the rotor blade relative to the arm in which the rotor blade is located.
A drone according to claim 14, wherein when said center of gravity of said drone is changed, said change in state of said power means includes rotating said center of gravity in a direction of approaching said center portion Set the rotor blades on the arm.
The drone of claim 14 wherein the angle at which said rotor blade rotates relative to its arm is determined based on said center of gravity offset.
The drone according to claim 2, wherein when the center of gravity of the drone is changed, the rotation speed of the rotor blades provided on one or more of the arms is also changed to counteract the drone The change of focus.
The drone according to claim 17, wherein the rotational speed of said rotor blade is determined according to the following formula (a):

Where x, y, z are the body coordinates of the drone, Φ is the roll angle of the drone along the X axis; Θ is the pitch angle of the drone along the Y axis; The yaw angle of the Z axis.

Where k m is the coefficient between the rotor output force and the rotational speed ω i , i is a positive integer representing the number of the rotor; m is the mass of the drone.
The drone according to claim 18, wherein said rotational speed is set to said predetermined rotational speed limit value when said rotational speed determined according to formula (a) is greater than a predetermined rotational speed limit value.
The drone according to claim 19, wherein the number of said rotors is four, and a distance between an axis of said rotor blade and a center of said center portion is determined according to the following formula (b):

Where ω i is the rotor speed determined according to formula (a), and ω i is not greater than the predetermined speed and limit; k d is a coefficient between the rotor output torque and the rotational speed ω i ; l 1 ～ l 4 The distance from the rotor blade axis to the center of the drone. l x , l y , l z are inertia along the X, Y, and Z axes.
The drone according to claim 2, wherein the change in the center of gravity of the drone is a result of a change in state of one or more loads provided on the drone.
The drone according to claim 21, wherein when the center of gravity of the drone is changed, the position of the load relative to the center of the drone can be changed in combination.
The drone according to claim 22, wherein the change in the position of the load relative to the center of the drone includes at least one of a load and a carrier carrying the load The center of the machine rotates.
A drone according to claim 23, wherein said carrier includes a base connecting said carrier to a center portion of said drone, a fixing member coupled to said base, and said a movable member on the fixing member, the movable member being rotatable about a pitch axis and a roll axis of the fixing member, the load being disposed on the movable member.
The drone according to claim 24, wherein said base is rotatable about a yaw axis with respect to a center portion of said drone.
The drone according to claim 25, wherein said base and said movable member are each provided with a sensor capable of sensing a rotation of said load relative to said central portion.
A drone according to claim 23, wherein said load or carrier carrying said load is provided with a sensor, said sensor being capable of sensing a predetermined change in the state of said load when said load When the state is changed, it is determined that the center of gravity of the drone has changed.
A drone according to claim 27, wherein said predetermined change in state of said load comprises a portion of said load moving away from or near said drone in a direction away from a center of gravity of said drone The center moves.
A UAV attitude control method, characterized in that:

Determining that the center of gravity of the drone has changed; and

The state of at least one of the power arm and the power device disposed on the arm is changed to counteract the center of gravity change of the drone.
The method of claim 29, wherein the method further comprises changing a rotational speed of the rotor blades of the power unit disposed on the arm to counteract a change in the center of gravity of the drone.
The method of claim 30 wherein: "changing the state of at least one of the power arm and the power device disposed on the arm to counteract the center of gravity change of the drone" includes:

Obtaining the flight status parameters of the drone;

When the center of gravity of the drone changes, the target rotational speed of the rotor blade of the drone is calculated according to the acquired parameters;

Determining whether the calculated target rotational speed is greater than a predetermined limit rotational speed value ω t ;

When the calculated target rotational speed is greater than the predetermined limit rotational speed value ω t , setting the target rotational speed to the limit rotational speed value ω t ;

Calculating a distance from a center of the drone to the rotor blade according to the determined target rotational speed; and

And adjusting a current speed of the drone and a distance from a center of the drone to the rotor blade according to a target rotational speed and a calculated distance from a center of the drone to the rotor blade.
The method of claim 31 wherein "adjusting the distance of the center of the current drone to the rotor blade" comprises changing the state of one or more of the arms.
32. The method of claim 32 wherein the change in state of the arm comprises linear extension or contraction of the arm in the direction of extension of the arm.
A method according to claim 33, wherein when said center of gravity of said drone is changed, said change in said arm state comprises linearly extending said center of gravity offset direction in a direction away from said central portion The arm or the arm disposed in the opposite direction to the direction in which the center of gravity is offset linearly in a direction toward the center portion.
The method of claim 32 wherein the changing of the state of the arm comprises folding of the arm at at least one designated point on the arm.
The method according to claim 35, wherein when the center of gravity of the drone is changed, the change in the state of the arm includes folding the arm disposed in the opposite direction of the direction of offset of the center of gravity.
The method of claim 31 wherein "adjusting the current distance of the center of the drone to the rotor blade" comprises changing a state of the power unit disposed on one or more of the arms.
38. The method of claim 37 wherein the changing of the state of the power unit disposed on the arm includes changing the position of its rotor blade on the corresponding arm.
A method according to claim 38, wherein when said center of gravity of said drone is changed, said change in state of said power means includes linearly moving said center of gravity offset direction in a direction away from said center portion Rotor blades on the arm or linearly move the rotor blades on the arm disposed in opposite directions of the center of gravity offset direction toward the center portion.
38. The method of claim 37 wherein the change in state of the power unit disposed on the arm includes rotation of the rotor blade relative to the arm in which the rotor blade is located.
A method according to claim 40, wherein when the center of gravity of said drone is changed, said change in state of said power means includes rotating said center of gravity offset direction in a direction close to said center portion Rotor blades on the arm.
The method of claim 31 wherein said rotational speed of said rotor blade is determined according to equation (a):

Where x, y, z are the body coordinates of the drone, Φ is the roll angle of the drone along the X axis; Θ is the pitch angle of the drone along the Y axis; The yaw angle of the Z axis.

Where k m is the coefficient between the rotor output force and the rotational speed ω i , i is a positive integer representing the number of the rotor; m is the mass of the drone.
The method according to claim 42, wherein said rotational speed is set to said predetermined rotational speed limit value when said rotational speed determined according to formula (a) is greater than a predetermined rotational speed limit value.
The method according to claim 43, wherein the number of said rotors is four, and the distance between the axis of said rotor blades and the center of said center portion is determined according to the following formula (b):

Where ω i is the rotor speed determined according to formula (a), and ω i is not greater than the predetermined speed and limit; k d is a coefficient between the rotor output torque and the rotational speed ω i ; l 1 ～ l 4 The distance from the rotor blade axis to the center of the drone. l x , l y , l z are inertia along the X, Y, and Z axes.
The method of claim 29 wherein the change in the center of gravity of the drone is a result of a change in state of one or more loads provided on the drone.
The method according to claim 45, wherein when the center of gravity of the drone is changed, the position of the load relative to the center of the drone can also be changed.
The method of claim 46 wherein said change in position of said load relative to said central portion of said drone includes at least one of a load and a carrier carrying said load relative to said drone The center rotates.
A method according to claim 47, wherein said carrier comprises a base connecting said carrier to a central portion of said drone, a fixing member coupled to said base, and a fixing member disposed at said fixing member The upper movable member is rotatable about a pitch axis and a roll axis of the fixing member, and the load is disposed on the movable member.
The method of claim 48 wherein said base is rotatable about a yaw axis relative to a central portion of said drone.
The method according to claim 49, wherein said base and said movable member are provided with sensors for sensing rotation of said carrier relative to said central portion.
A method according to claim 47, wherein said load or carrier carrying said load is provided with a sensor capable of sensing a predetermined change in the state of said load when said state of said load is predetermined When the change is made, it is determined that the center of gravity of the drone has changed.
A method according to claim 51, wherein the predetermined change in the state of the load includes a portion of the load moving away from or near the center of the drone in a direction away from the center of gravity of the drone mobile.
A control device for controlling a posture of a drone, characterized in that: the control device includes a gravity center control portion, and the gravity center control portion is configured to change according to a gravity center of the drone when a gravity center of the drone changes Determining the change in state of the power unit provided on one or more of the arms or arms.
The control device according to claim 53, wherein said center of gravity control portion comprises:

a gravity center determining unit configured to determine a change in a center of gravity of the drone;

An arm selection unit configured to determine an arm that needs to be changed according to a change in a center of gravity;

An arm length determining portion for determining a distance from an axis of the rotor blade provided on the arm to a center of the drone according to a change in the center of gravity; and

The configuration determining unit is configured to determine a state change of the arm or the power unit based on the distance determined by the arm length determining unit.
The control apparatus according to claim 54, wherein the change in the state of the arm includes linear extension or contraction of the arm in the extending direction of the arm.
A control apparatus according to claim 55, wherein when said center of gravity of said drone is changed, said change in said arm state includes linearly extending said center of gravity offset direction away from said center portion The disposed arm or the arm disposed in the opposite direction to the direction in which the center of gravity is offset is linearly contracted toward the center portion.
The control device of claim 53 wherein the change in state of the arm comprises folding of the arm at at least one designated point on the arm.
A control apparatus according to claim 56, wherein when said center of gravity of said drone is changed, said change of said arm state includes folding said arm provided in a direction in which said center of gravity is offset.
A control apparatus according to claim 54, wherein the change in the state of the power unit provided on said arm includes changing the position of its rotor blade on the corresponding arm.
A control apparatus according to claim 58, wherein when said center of gravity of said drone is changed, said change in state of said power means includes linearly moving said center of gravity in a direction away from said center portion The rotor blades on the provided arm or the rotor blades on the arm disposed in the opposite direction to the direction in which the center of gravity is displaced are linearly moved toward the center portion.
54. A control apparatus according to claim 54 wherein the change in state of the power unit disposed on the arm includes rotation of the rotor blade relative to the arm in which the rotor blade is located.
A control apparatus according to claim 60, wherein when said center of gravity of said drone is changed, said change in state of said power means includes rotating said opposite direction of the center of gravity offset in a direction toward said center portion Rotor blades on the arm that are oriented in the direction.
The control device according to claim 54, wherein when the center of gravity of the drone is changed, the rotational speed of the rotor blade provided on one or more of the arms can be changed to counter the center of gravity of the drone. Change.
A control device according to claim 62, wherein said rotor blade speed Determine according to the following formula (a):

Where x, y, z are the body coordinates of the drone, Φ is the roll angle of the drone along the X axis; Θ is the pitch angle of the drone along the Y axis; The yaw angle of the Z axis.

Where k m is the coefficient between the rotor output force and the rotational speed ω i , i is a positive integer representing the number of the rotor; m is the mass of the drone.
The control device according to claim 63, wherein said rotational speed is set to said predetermined rotational speed limit value when said rotational speed determined according to formula (a) is greater than a predetermined rotational speed limit value.
The control apparatus according to claim 64, wherein the number of said rotors is four, and a distance between an axis of said rotor blade and a center of said center portion is determined according to the following formula (b):

Where ω i is the rotor speed determined according to formula (a), and ω i is not greater than the predetermined speed and limit; k d is a coefficient between the rotor output torque and the rotational speed ω i ; l 1 ～ l 4 The distance from the rotor blade axis to the center of the drone. l x , l y , l z are inertia along the X, Y, and Z axes.
The control device according to claim 53, wherein the change in the center of gravity of said drone is a result of a change in state of one or more loads provided on said drone.
The control device according to claim 66, wherein when the center of gravity of the drone is changed, the position of the load relative to the center of the drone can be changed in combination.
A control apparatus according to claim 67, wherein said change in position of said load relative to said central portion of said unmanned aerial vehicle comprises at least one of a load and a carrier carrying said load relative to said drone The center of the rotation.
A control apparatus according to claim 68, wherein said carrier includes a base connecting said carrier to a center portion of said drone, a fixing member coupled to said base, and said fixing a movable member on the piece, the movable member being able to rotate around the pitch axis and the roll axis of the fixing member Turning, the load is placed on the movable member.
The control device according to claim 69, wherein said base is rotatable about a yaw axis with respect to a center portion of said drone.
A control apparatus according to claim 70, wherein said base and said movable member are provided with sensors for sensing rotation of said carrier with respect to said central portion.
A control apparatus according to claim 68, wherein said load or carrier carrying said load is provided with a sensor capable of sensing a predetermined change in the state of said load, when the state of said load When the change is scheduled, it is determined that the center of gravity of the drone has changed.
A control apparatus according to claim 72, wherein said predetermined change in state of said load comprises a portion of said load moving away from or near a center of said drone in a direction deviating from a center of gravity of said drone Department moves.