CN106608350B

CN106608350B - Multi-rotor aircraft

Info

Publication number: CN106608350B
Application number: CN201510690611.8A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Shenzhen Kuang Chi Hezhong Technology Ltd
Current assignee: Foshan Shunde Guangqi Advanced Equipment Co ltd
Priority date: 2015-10-22
Filing date: 2015-10-22
Publication date: 2024-03-15
Anticipated expiration: 2035-10-22
Also published as: CN106608350A; WO2017067412A1

Abstract

A multi-rotor aircraft is disclosed. The multi-rotor aircraft comprises: an air bag comprising a bag body; a multi-rotor system including a main support located in an inner space of the air bag, a plurality of motors and a plurality of propellers located outside the air bag, and a plurality of connection brackets for connecting the main support and the plurality of motors, the plurality of motors driving the plurality of propellers, respectively; a driving circuit for driving the plurality of motors and adjusting the rotational speeds thereof; and a power supply including a photovoltaic module and a rechargeable battery for supplying power to the driving circuit. The multi-rotor aircraft utilizes a multi-rotor system and an air bag as dual lift sources, and adopts a photovoltaic assembly and a rechargeable battery as dual power sources, thereby being capable of prolonging the dead time.

Description

Multi-rotor aircraft

Technical Field

The present invention relates to the field of aeronautics, and more particularly to a multi-rotor aircraft.

Background

Aerostatics have been widely used for air transportation. Aerostat refers to an aircraft that utilizes lighter-than-air gases to provide lift. According to the working principle, aerostats can be classified into airships, tethered balloons and hot air balloons. The aerostat includes a bladder for containing a gas having a specific gravity less than that of air (e.g., hot air, hydrogen, or helium) to obtain lift. The aerostat has simple structure, low cost and long residence time in the air. However, precise control of the aerostat is difficult. In the vertical direction, the aerostat can be controlled to rise or fall by the inflation and deflation gas. However, in the horizontal direction, the movement of the aerostat depends on natural wind or an additional power device, and not only the movement speed is slow but also the operation is difficult.

In recent years, multi-rotor aircraft have attracted more and more attention. Existing multi-rotor aircraft employ multiple propellers to provide lift and power for horizontal movement, each propeller driven by a respective one of the motors. Fig. 1 is a schematic block diagram of a control system for a multi-rotor aircraft according to the prior art. The control system includes a main control module 101. The main control module 101 is powered by a rechargeable battery 102, such as a lithium battery. The main control module 101 receives remote control instructions or feedback data from the receiver 103 and generates control signals that are provided to the electronic governor modules 104a-104d, respectively, to control the rotational speed of the motors M1-M4. The rotation speed of each propeller is controlled to realize free orbit and posture adjustment in all directions.

The multi-rotor aircraft adopts a single lithium battery power supply system, and realizes the driving of a multi-axis rotor system by using high-rate discharge. Due to the capacity limitation of lithium batteries, the achievable flight time of the multi-rotor aircraft is only about 15-30 minutes, thereby restricting the application range.

Accordingly, it is desirable to develop long-term airborne aircraft that combine the advantages of aerostats and multi-rotor aircraft.

Disclosure of Invention

The invention aims to provide a multi-rotor aircraft which adopts a multi-rotor system and an air bag as dual lift force sources and adopts a photovoltaic assembly and a rechargeable battery as dual power sources so as to prolong the dead time.

According to an aspect of the present invention, there is provided a multi-rotor aircraft comprising: an air bag comprising a bag body; a multi-rotor system including a main support located in an inner space of the air bag, a plurality of motors and a plurality of propellers located outside the air bag, and a plurality of connection brackets for connecting the main support and the plurality of motors, the plurality of motors driving the plurality of propellers, respectively; a driving circuit for driving the plurality of motors and adjusting the rotational speeds thereof; and a power supply including a photovoltaic module and a rechargeable battery for supplying power to the driving circuit.

Preferably, the power supply further includes a dc voltage conversion module, and the photovoltaic module is connected to the dc voltage conversion module, so that after the current generated by the photovoltaic module is converted by the dc voltage conversion module, the rechargeable battery is continuously float charged to supplement electric energy, or directly supplies power to the driving circuit.

Preferably, the multi-rotor aircraft further comprises a battery box at the bottom of the capsule for accommodating the rechargeable battery and the direct-current voltage conversion module.

Preferably, the photovoltaic module is a monocrystalline silicon photovoltaic module or a flexible film photovoltaic module.

Preferably, the top middle surface of the capsule is a plane or a curved surface.

Preferably, the photovoltaic module is mounted on top of the capsule.

Preferably, the photovoltaic module conforms to the top of the capsule.

Preferably, the capsule is formed from one selected from the following materials: high-strength reinforced fiber cloth, PVC film, polyester film and polyester fiber film.

Preferably, the multi-rotor aircraft further comprises: and the plurality of pull belts are used for connecting the inner surface of the bag body with the plurality of connecting brackets, and the lengths of the plurality of pull belts are arranged according to the shape of the air bag, so that the shape of the air bag is maintained in an inflated state.

Preferably, the plurality of connection brackets are respectively hollow tubular, and lead wires are used from the driving circuit, pass through the plurality of connection brackets to reach the plurality of motors, and are used for providing driving voltages for the plurality of motors.

Preferably, the multi-rotor aircraft further comprises: sealant for filling the inner spaces of the plurality of connection brackets; and a flange structure for connection between the plurality of connection brackets and the bladder, wherein the sealant and the flange structure together maintain the air tightness of the bladder.

Preferably, the number of the plurality of propellers is 4 or more.

Preferably, the main support and the plurality of connection supports form an axisymmetric pattern with a central axis of the balloon, wherein the plurality of connection supports are equiangularly distributed in a plane perpendicular to the central axis.

Preferably, the plurality of connection brackets have equal lengths, and the plurality of motors and the plurality of propellers are respectively installed at ends such that the plurality of propellers are equidistant from a central axis of the capsule.

Preferably, the central axes of the plurality of motors and the plurality of propellers are respectively parallel to the central axis of the capsule body, so that air flow in the vertical direction is generated during operation, and lift force is formed.

In the multi-rotor aircraft according to the embodiment of the invention, not only the gas contained in the air bag is used as a lift force source, but also a multi-rotor system is used for providing the lift force source and realizing the movement control in the horizontal direction. Because the air bags provide at least a portion of the lift required for the multi-rotor aircraft to stagnate, the multi-rotor system is capable of achieving hover, vertical movement, and horizontal movement of the multi-rotor aircraft even when operating at lower rotational speeds. Multi-rotor systems provide power for horizontal movement and vertical movement for multi-rotor aircraft. The multi-rotor aircraft adopts the combination of the air bags and the multi-rotor system, so that the energy consumption of the multi-rotor system can be reduced, and the dead time can be prolonged.

Further, the multi-rotor aircraft adopts a combination of a rechargeable battery and a photovoltaic module, and the top of the air bag is utilized to provide an installation space of the photovoltaic module. The photovoltaic module can generate enough electric energy output, continuously float-charge the rechargeable battery to supplement electric energy, or directly supply power to the system. Due to the additional source of electrical energy, the dead time can be further prolonged.

In addition, since a plurality of connection brackets are used to connect the components inside and outside the airbag, a compact external shape can be achieved, improving the handling performance.

The multi-rotor aircraft can be applied to various occasions requiring long-time air stagnation and horizontal mobility. For example, the multi-rotor aircraft may carry communication equipment for emergency rescue and relief work as a transfer station for communication, or collection equipment for climate monitoring, data collection, or monitoring equipment for long-term monitoring.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:

FIG. 1 is a schematic block diagram of a drive circuit for a multi-rotor aircraft according to the prior art;

FIG. 2 is a schematic block diagram of a drive circuit for a multi-rotor aircraft according to an embodiment of the invention;

figure 3 is a schematic perspective view of a multi-rotor aircraft according to an embodiment of the invention;

figures 4a and 4b are top and cross-sectional views of a multi-rotor aircraft according to an embodiment of the present invention.

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings. Like elements are denoted by like reference numerals throughout the various figures. For clarity, the various features of the drawings are not drawn to scale. Furthermore, some well-known portions may not be shown. The structure obtained after several steps may be depicted in one figure for simplicity.

It will be understood that when a layer, an area, or a structure of a device is described as being "on" or "over" another layer, another area, it can be referred to as being directly on the other layer, another area, or further layers or areas can be included between the other layer, another area, etc. And if the device is flipped, the one layer, one region, will be "under" or "beneath" the other layer, another region.

If, for the purposes of describing a situation directly on top of another layer, another region, the expression "a directly on top of B" or "a directly on top of B and adjoining it" will be used herein. In this application, "a is directly in B" means that a is in B, and not a is in the doped region formed in B.

Numerous specific details of the invention, such as materials, dimensions, processing and techniques, are set forth in the following description in order to provide a thorough understanding of the invention. However, as will be understood by those skilled in the art, the present invention may be practiced without these specific details.

The invention may be embodied in various forms, some examples of which are described below.

Fig. 2 is a schematic block diagram of a drive circuit for a multi-rotor aircraft according to an embodiment of the invention. The drive circuit includes a main control module 101. The main control module 101 is powered by a rechargeable battery 102, such as a lithium battery. The main control module 101 receives remote control instructions or feedback data from the receiver 103 and generates control signals that are provided to the electronic governor modules 104a-104d, respectively, to control the rotational speed of the motors M1-M4. The rotation speed of each propeller is controlled to realize free orbit and posture adjustment in all directions.

The driving circuit further includes a photovoltaic module 201 and a direct-current voltage conversion module 202, thereby employing the photovoltaic module and a rechargeable battery as dual power sources.

The photovoltaic module 201 includes various types of monocrystalline silicon, polycrystalline silicon, copper indium gallium selenide, gallium arsenide, dye sensitized batteries, and the like, and can convert solar energy into electric energy to provide energy for electronic equipment. The photovoltaic module can provide additional energy source supplement for the whole system to a certain extent. Photovoltaic modules are difficult to achieve instantaneous high-current power supply under a limited size and a specific voltage regime, and therefore cannot be used alone as a power supply source for a system, and are required to be used together with a battery having high-rate discharge capability.

As will be described below, the multi-rotor system according to embodiments of the present invention also includes an air bag, thereby providing space for installation of large-area photovoltaic modules. Therefore, in the driving circuit of the present invention, the photovoltaic module 201 can provide sufficient energy source supplement, and even can be used as an independent power supply source.

In the embodiment shown in fig. 2, a rechargeable battery 102, such as a lithium battery, is used that supports float operation. The photovoltaic module 201 continuously supplies power to the rechargeable battery 102 through the direct-current voltage conversion module 202, and the rechargeable battery 102 supplies power to the high-current system components such as the electronic speed regulation modules 104a-104d and the like through the main control module 101.

Monocrystalline silicon and flexible thin film photovoltaic modules are the two most cost effective candidates in the choice of photovoltaic modules 201. Monocrystalline silicon has high conversion efficiency, but has larger weight after encapsulation. The efficiency of the flexible battery piece is only about half that of monocrystalline silicon, but the flexible battery piece is light in weight, easy to conform and good in comprehensive effect.

Fig. 3 is a schematic perspective view of a multi-rotor aircraft according to an embodiment of the invention, and fig. 4a and 4b are a top view and a cross-sectional view of a multi-rotor aircraft according to an embodiment of the invention, wherein the cross-sectional view shown in fig. 4b is taken along the centerline AA of the top view shown in fig. 4 a.

The multi-rotor aircraft 500 employs a multi-rotor system and an air bag as dual lift sources. The balloon includes an inflatable balloon body 510. The balloon shape is shown in the inflated state. As shown, in the inflated state, the bladder 510 is cylindrical in shape with a flat top to facilitate installation of the photovoltaic module.

By way of example, capsule 510 is shown as circular in the top view of fig. 4a, and as approximately rectangular in the cross-sectional view of fig. 4b, taken through capsule 510 in a plane parallel to the central axis of capsule 510. However, the cross-sectional shape of the capsule 510 is not limited thereto, and may be elliptical, or the outer contour may be a closed shape composed of a curve selected from at least one of a parabolic arc, a hyperbolic arc, and a piecewise curve.

The air bags are used for providing at least a portion of the lift required for the multi-rotor aircraft to stagnate. For this, the capsule 510 contains a gas having a specific gravity smaller than that of air, such as hydrogen or helium, to provide lift. The material of the capsule 510 should be airtight. For example, the bladder 510 is made of high strength reinforcing fiber cloth. Alternatively, the material of the capsule 510 may be a PVC film, a polyester fiber film if the mechanical strength of the capsule is not required.

A photovoltaic module 201 is mounted on top of the capsule 510. Advantageously, the capsule 510 has a flat top so that either of monocrystalline silicon and flexible thin film photovoltaic modules can be mounted. In an alternative embodiment, if the top of the capsule 510 is curved, a flexible thin film photovoltaic module may be mounted that conforms to the top of the capsule 510.

A battery case 570 is mounted at the bottom of the pouch 510. The battery compartment 570 is configured to house the rechargeable battery 102 and the dc voltage conversion module 202. Inside the battery case 570, the rechargeable battery 102 and the dc voltage conversion module 202 are connected by a wire 206. The bottom of the battery compartment 570 is opened or closed by a valve structure to facilitate replacement and charging of the rechargeable battery 2102.

A shock absorbing bracket 580 is also designed at the bottom of the bag body 510 to play a role in taking off and landing protection. The shock mount 580 is mounted, for example, on the lower surface of the battery case 570. Outside the capsule 510, the photovoltaic module 201 is connected to the direct-current voltage conversion module 202 in the battery case 570 via the wire 205.

A main support 520, for example, composed of metal or alloy, is provided inside the balloon 510. A main circuit board 590 is provided on the main support 520. The main circuit board 590 includes, for example, the main control module 101, the receiver 103, and the electronic governor modules 104a-104d as shown in fig. 2. The main circuit board 590 and the rechargeable battery 102 are connected by the wire 207, so that the main circuit board 590 is supplied with power by the rechargeable battery 102.

A hanger bar 522, for example, composed of carbon fiber, is provided at the bottom of the main support 520 for hanging the battery case 570 under the main support 520.

Preferably, a plurality of pull straps 521 are used to connect the inner wall of bladder 510 and main support 520. In the inflated state, the surface shape of the balloon 510 is maintained by the pulling force of the pull tape to achieve the shape retention of the balloon 510. In addition, a multilayer drawstring arrangement may be employed. The multi-layer drawstring can better maintain the contours of the high volume airbag and can better conform the actual contours of the airbag to the design contours.

Each of the four connection brackets 530 has one end rigidly connected to the main bracket 520, and the other end extending to the outside through the balloon 510 for mounting the respective motor 550 and propeller 560. The attachment bracket 530 passes through the bladder 510 via a sealing flange structure 540.

Preferably, the main support 520 and the four connection supports 530 form a central symmetrical pattern, for example, an axisymmetrical pattern formed by the central axis of the balloon 510, wherein the four connection supports 530 are equiangularly distributed in a plane perpendicular to the central axis. Further preferably, the four connection brackets 530 have the same length, and the ends of the four connection brackets 530 are respectively mounted with the respective motors 550 and propellers 560 so as to be equidistant from the central axis of the balloon. The central axes of the motor 550 and the propeller 560 are parallel to the central axis of the bladder, so that in operation the propeller 560 generates an air flow in a vertical direction, creating a lift.

In another alternative embodiment, the four connecting brackets 530 may be disposed obliquely to the central axis of the capsule 510, and preferably the four connecting brackets 530 are at equal angles to the central axis of the capsule 510.

The connection bracket 530 may be hollow tubular, and a driving circuit for driving the motor 550 is provided in the main circuit board 590. The wires 208 start from the main circuit board 590, pass through the connection bracket 530 to the motor 550, and are used to supply a driving voltage to the motor 550. Inside the connection bracket 530, after the wire 208 is placed, the inner space is filled with sealant.

Due to the sealing with the sealant and the flange structure 540, the gas in the bladder 510 can be prevented from leaking through the inner space of the connection bracket 530 or the joint between the connection bracket and the bladder 510, thereby maintaining the air tightness of the bladder 510.

In operation, the multi-rotor system varies rotor speed by adjusting the speed of the 4 motors 550 to achieve lift variation and control of flight direction. In the hover state, the 4 motors 550 are maintained at an equilibrium rotational speed such that the lift generated by the rotor and the net buoyancy provided by the capsule 510 are equal to the deadweight of the aircraft. While moving in the vertical direction, the vertical ascent is achieved by simultaneously increasing the rotational speeds of the 4 motors 550, and the vertical descent is achieved by simultaneously decreasing the rotational speeds of the 4 motors 550. When moving in the horizontal direction, the rotation speed of the first motor in front along the movement direction is reduced, the rotation speed of the second motor in rear along the movement direction is increased, and the balance rotation speeds of the other two motors are maintained, so that the aircraft tilts to a certain degree first and then generates thrust for forward movement.

The balloon 510 is designed to have a certain aerodynamic shape. By design of the material, shape, size, and fill gas, bladder 510 is capable of providing an effective net buoyancy after inflation. Therefore, the following relationship needs to be satisfied among the parameters of the volume V, the surface area S, the material density D1, the filling gas density D2, the air density D3, the weight M of other parts of the whole machine, and the like of the capsule 510:

M＞V×(D3-D2)-S×D1＞0，

i.e., the net buoyancy provided by bladder 510 must be greater than zero, but not greater than the sum of the weights of the other components of the system, except bladder 510.

Under this design, the buoyancy that the capsule 510 provided can effectively offset the partial weight of other parts of system, lighten the departure weight of system, reduce the requirement to the screw thrust, and then reduce the consumption of during operation, realize the extension of flight time.

The effects of the multi-rotor aircraft of the present invention on the drag are analyzed as follows. As shown in table 1, the bare weight of multi-rotor aircraft 500 was about 6kg (including the battery) and the effective flight time was about 25 minutes without the inclusion of airbags and photovoltaic modules. In accordance with an embodiment of the present invention, multi-rotor aircraft 500 is combined with an airbag, and CIGS flexible thin film photovoltaic module 201 is mounted on top of the airbag body 510. As a result, the hover time of the multi-rotor aircraft is obviously prolonged, reaches a value of about 57 minutes, is doubled compared with the original system, and has obvious effect.

Table 1: hover time analysis for multi-rotor aircraft

Frame weight (kg)	4.2
		Rechargeable electric powerPool weight (kg)	1.8
Rechargeable battery model	6S 16000mAh
		Rechargeable battery electric quantity (Wh)	355
Weight of air bag (kg)	1.7
		Balloon volume (m) ³ )	5.3
Buoyancy gas	Helium gas
		Total buoyancy (kg)	5.9
CIGS photovoltaic module weight (kg)	3.3
		CIGS photovoltaic module power (W)	750
Additional structural weight (kg)	2.0
		Net weight (kg)	7.1
Hover net power consumption (W)	374
		Hover time (min)	57.0

In the above-described embodiments, a multi-rotor system for a multi-rotor aircraft is described that includes 4 propellers. It will be appreciated that a multi-rotor system may include more propellers to achieve more complex flight attitudes.

The embodiments of the present invention are described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be made by those skilled in the art without departing from the scope of the invention, and such alternatives and modifications are intended to fall within the scope of the invention.

Claims

1. A multi-rotor aircraft, comprising:

an air bag comprising a bag body;

a photovoltaic module conformal with the top of the capsule;

a multi-rotor system including a main support located in an inner space of the air bag, a plurality of motors and a plurality of propellers located outside the air bag, and a plurality of connection supports for connecting the main support and the plurality of motors, the plurality of motors driving the plurality of propellers, respectively, the plurality of connection supports being hollow tubular, respectively, and starting from a driving circuit using wires, passing through the plurality of connection supports to the plurality of motors for providing driving voltages to the plurality of motors;

a driving circuit provided on the main frame for driving the plurality of motors and adjusting the rotational speeds thereof; and

the power supply is positioned at the bottom of the bag body and comprises a photovoltaic module and a rechargeable battery for supplying power to the driving circuit,

a plurality of pull straps for connecting the inner surface of the balloon body with the plurality of connection brackets, the plurality of pull straps having lengths arranged in accordance with the outer shape of the balloon so as to maintain the outer shape of the balloon in an inflated state;

sealant for filling the inner spaces of the plurality of connection brackets; and

a flange plate structure for connecting the plurality of connecting brackets with the bag body,

the sealing glue and the flange plate structure together maintain the air tightness of the capsule body, the main support and the plurality of connecting supports form axisymmetric patterns with the central shaft of the capsule body, wherein the plurality of connecting supports are distributed in a plane perpendicular to the central shaft at equal angles, the lengths of the plurality of connecting supports are equal, and the plurality of motors and the plurality of propellers are respectively arranged at the end parts, so that the distances between the plurality of propellers and the central shaft of the capsule body are equal.

2. The multi-rotor aircraft of claim 1, wherein the power supply further comprises a dc voltage conversion module, the photovoltaic assembly being connected to the dc voltage conversion module such that after the current generated by the photovoltaic assembly is converted by the dc voltage conversion module, the rechargeable battery is continuously recharged to supplement the electrical energy or directly power the drive circuit.

3. The multi-rotor aircraft of claim 2, further comprising a battery compartment at a bottom of the pocket for housing the rechargeable battery and the dc voltage conversion module.

4. The multi-rotor aircraft of claim 2, wherein the photovoltaic module is a monocrystalline silicon photovoltaic module or a flexible thin film photovoltaic module.

5. The multi-rotor aircraft of claim 2, wherein the top mid-surface of the bladder is planar or curved.

6. The multi-rotor aircraft of claim 5, wherein the photovoltaic assembly is mounted on top of the bladder.

7. The multi-rotor aircraft of claim 1, wherein the bladder is formed from one selected from the group consisting of: high-strength reinforced fiber cloth, PVC film, polyester film and polyester fiber film.

8. The multi-rotor aircraft of claim 1, wherein the number of the plurality of propellers is 4 or more.

9. The multi-rotor aircraft of claim 1, wherein the central axes of the plurality of motors and the plurality of propellers are each parallel to the central axis of the bladder, such that in operation a vertical direction of airflow is generated, creating lift.