DE102005014949A1 - Multi-rotor helicopter e.g. reconnaissance drone for urban areas, has support frame divided into at least two groups of structures mechanically connected together as such that electrical connection between groups is possible - Google Patents

Abstract

A helicopter (30) has four propeller units (40) each with a rotor (1) and an electric motor (2) and a support frame (3) divided into at least two groups of structures (35) mechanically and foldably connected together via coupling (60). Electrical connection between the groups using e.g. electrical lines or contact elements, is enabled. The coupling used provides at least one degree of freedom for translatory movement. Parts of the coupling are of fiber-reinforced plastics. An independent claim is also included for a method of changing the dimensions of a helicopter.

Description

background the invention

helicopter are rotorcraft aircraft with at least a motor-driven rotor. There are numerous embodiments with different numbers of rotors in different arrangements.

little one and light helicopters, mainly with electric drive, win as an unmanned camera carrier, measuring platforms and reconnaissance drones increasingly important. The development is pushed through the continuous development of electrical energy storage, to always higher Energy and power density.

In this writing is about a specific type of helicopters, namely to those with three or more lifting units (so-called Mehrrotorenhubschrauber). Under lifting unit, the combination of at least one rotor with understood at least one motor driving the rotor. The lifting units can also contain other components, eg. B. gear or speed controller. The combination of exactly one rotor with exactly one motor is the most frequent execution a lifting unit. The axes of the rotors are typically (approximately) vertical. The rotors serve primarily the lift generation - therefore the Name lifting unit.

highlight is the 4-rotor helicopter, which has system-related advantages and whose economic benefits are increasing, accelerated by current ones Developments of improved attitude stabilization techniques, which are particularly effective in this helicopter type to let. Among the advantages of the 4-rotor concept is the possibility a controller to all axes alone about the speed of four rigid Rotors, so without mechanics except rotating shafts, in particular without collective and cyclic rotor blade adjustment. 4-rotor helicopters can Accordingly, be built mechanically very minimalist.

In the plan view are the lifting units of 4-rotor helicopters almost always arranged at the corners of a square, often at the corners a square. The center distances are usually so big that the circular surfaces defined by the rotors are straight do not overlap. With that you can the rotors are arranged on one level without touching each other.

Out establish For aerodynamic efficiency, the rotors should be rather large in diameter have (low circular surface load). With increasing diameter but also grow the outer dimensions of the helicopter. The big ones Disturb dimensions especially during storage and transport.

a Approach to miniaturization of 4-rotor helicopters supplies the German utility model no. 20 2004 016 509.0. After that are the center distances the rotors smaller, with overlap the rotor circuit surfaces accompanied. To avoid collisions, the rotors work here at different heights. Disadvantages of this solution: slightly reduced efficiency and a louder rotor noise through the (tightly) past each other Rotor blades. In a number of applications these disadvantages are unacceptable, z. B. in reconnaissance drones, which should remain undetected.

The Requirements for compact design are z. T. extremely strict. So should in the future Persons walking on foot are reconnaissance aircraft in backpacks or Carry handbags with you (eg for the search for survivors from earthquakes inside and outside in danger of collapsing Building). As Mehrrotorenhubschrauber has such a device with the currently available (camera) technology around one meter total size. (Background:

Of the Invention is therefore based on the object, an electrically driven Multi rotor helicopter with as possible to create small transport dimensions, at the same time high Efficiency, low noise, easy operation and short set-up time. The invention is Furthermore, the object of a method for change indicate the dimensions of a multi-rotor helicopter.

Short outline the invention

According to the invention Task solved by splitting the helicopter support frame. The shoring on which the lifting units are attached and connected together is on shared at least one place, so that the helicopter out at least consists of two modules. The individual modules are by at least a joint mechanically coupled. The helicopter is in it Size changeable, can zusammen- and be unfolded again. (The terms "combined" and unfold " synonymous here synonymous for "together and push apart ", So for rotational and translational joint movement alike.)

By the articulated version of the shoring The space required for storage and transport of the aircraft can be considerable be reduced, even if the center distances of the rotors are made so large, that the rotor circuit surfaces do not overlap in the top view (low noise).

Because the individual lifting units are supplied with electrical energy and must be controlled by a control unit, in addition to the mechanical Coupling of the assemblies also provided an electrical.

At least according to the invention an electrical connection exists between the assemblies, the electrical components of various modules electrically conductive connects. These electrical components include all devices that working with electric current (speed controller, electric motors, control electronics Etc.).

To a first embodiment of the invention the electrical connection electrical contacts. The contacts can (automatically) be closed when the aircraft is unfolded in flight position becomes.

The electrical connection may include an electrical wiring. This can preferably be made flexible. Due to their flexibility, a Movement of the joint allows be without disconnecting the line. The line can therefore preferably so arranged and misplaced that they are a movement of the joint can follow, so does not block the joint movement. agility in the joint is therefore given, even without the line disconnected is, for. B. by loosening a plug connection. In joint movement, the flexible, electrical Line to be subjected to bending and / or torsion.

The Line may preferably be guided in the immediate vicinity of the joint, be formed with or without plug connection.

typically, At least three individual electrical lines per lifting unit are provided (Plus, minus, signal), which combined to form a multi-core cable could be, with which the modules are electrically bridged.

If the lines at the joints of the shoring assemblies are designed without plug connection, also possible contact problems be excluded in principle on such plug contacts. Further Advantages: The workload for the assembly and disassembly is eliminated. A mating of Plug connections can not be forgotten - malfunction due to lack of contact locked out.

It but may also be useful to provide yet plug connections, z. B. to completely separate assemblies or exchange to be able to.

The electrical line may contain a strand, preferably one fine stranded copper wire with PVC or silicone sheath, which also after numerous bending changes does not tend to cable break.

According to one another embodiment of the invention Assemblies of the helicopter with at least one joint with a single degree of freedom.

One Joint can realize a translational movement. It can be axial movable articulated structures or sliding seats (sliding joint) get used for mechanical coupling of the modules. Components can be formed telescopically (telescopic joint).

The Movement of the joint may preferably be a rotary or pivoting movement be. Swivel joints have opposite Sliding joints usually have the advantage that the electrical connection be carried out with a shorter length of electric cable can.

The Joints can in different numbers and in different places of the helicopter to be appropriate. The spatial Orientation may vary, as well as the structural design. So can the Rotary axes of all joints lie on one axis. It may preferably a single, two or three joints may be provided.

The The axis of rotation of a joint can be approximately vertical or horizontal, depending on the desired degree of freedom. It can also be a single joint with approximately vertical axis to be used.

The Movement of a joint can be limited with a stop. The Flight position can be locked. The joint can also be self-locking remain in a (certain) position, without locking mechanism.

When Material for Joint components can fiber reinforced Plastics find use, preferably carbon fiber reinforced. These Materials are characterized by low weight and high strength out.

The Leaf number of (preferably rigid) rotors can vary. conventional Rotors have two or more rotor blades. Compact dimensions can be achieved when the rotor blades of a rotor in one Escape, as is typically the case with two-bladed rotors. The rotors can also only ever have one sheet, with a (short) counterweight on the other hand, as compensation for the rotating mass forces. The Counterweight may be formed as streamlined body (reduced Air resistance). With single-bladed rotors, the pack size can be changed on a case-by-case basis be reduced. The rotors can be turned into a space saving position in which the single Rotor blade protrudes less.

The Rotary planes formed by the rotors (turning planes) can have a (axial) distance from each other, preferably in the direction (vertical) axes of rotation of joints. With such a "height graduation" rotor blades in a collapsed position of the helicopter overlapping each other be pushed together even more narrowly and space-saving. A similar one Effect can with different distances of the lifting units to axes of rotation be achieved.

According to others Aspects of the invention may include the complete aircraft in one housed compact container be whose dimensions and / or volume are small.

The Take-off mass of the helicopter may be low, preferably below about 5 kg, more preferably less than about 1 kg.

• • Erzeugung einer Bewegung an einem Gelenk zwischen Baugruppen, einhergehend mit Vergrößerung oder Verkleinerung wenigstens einer Abmessung des Hubschraubers;
• • Drehung wenigstens eines Rotors in eine andere Position;
• • Sicherstellung einer elektrischen Verbindung zwischen Baugruppen in wenigstens einer Gelenkstellung.

Finally, the invention provides a method for changing the dimensions of a multi-rotor helicopter. The method contains the steps

• • generating motion at a joint between assemblies, accompanied by enlargement or reduction of at least one dimension of the helicopter;
• • rotation of at least one rotor to another position;
• • Ensuring an electrical connection between assemblies in at least one joint position.

at a preferred variant of the method may be a flexible, electrical Lead between assemblies follow a joint movement, without the line is disconnected (eg by loosening a plug connection).

In a (certain) joint position, all rotors can be free turn (preferred for Position "unfolded"). This position can be locked. It can also be the end position of a joint movement.

occasionally, a (further) reduction of the dimensions is possible if a rotor in one space-saving rotor position is turned.

any existing, electrical contacts between modules can with a joint movement (automatically) opened or closed.

Short description the drawings

Further Aspects and advantages of the invention will become apparent from the following Description of preferred embodiments, which will be explained with reference to the following figures.

1 shows a plan view of a 4-rotorigen helicopter in the unfolded state;

2 shows a side view of the helicopter according to 1 (simplistic without positions 40 right and left);

3 shows a top view of the helicopter after 1 in the folded state (variant 1 );

4 shows a top view of the helicopter after 1 in the folded state (variant 2 );

5 shows a plan view of the rotary joint of the helicopter after the 3 and 4 (simplistic without positions 4 and 70 );

6 shows a longitudinal sectional view of the rotary joint after 5 ;

7 shows a top view of the helicopter after 1 in the folded state (variant 3 );

8th shows a top view of the helicopter after 1 in the folded state (variant 4 );

9 shows a longitudinal sectional view of the three hinges of the helicopter after the 7 and 8th (simplistic without positions 70 ); and

the 10 to 31 show possible arrangements of joints in a schematic representation.

description preferred embodiments the invention

The 1 and 2 show a 4-rotor helicopter 30 in the unfolded state, which is suitable as a micro drone for aerial reconnaissance in urban terrain. The helicopter comprises a total of four lifting units 40 , The lifting units 40 each have one in the embodiment zweiblättrigen rotor 1 and an electric motor driving the rotor 2 , The lifting units 40 are on a support frame 3 attached and interconnected by this (core task of the framework, not only in this embodiment). The shoring 3 also carries a central control unit 4 , in which the power supply (battery) is housed, as well as a payload 5 , In the exemplary embodiment, this is a camera.

The technical data of the helicopter 30 are as follows: Rotor diameter: 380 mm Power requirement (hover): 16 W Flight time: 20 min Take-off weight: 300 g

Dimensions over everything:

On the support frame 3 Typically, the landing gear is also appropriate. In the present case, these are four stilt legs 10 , The shoring 3 can be composed of individual parts. Mechanically it represents - when unfolded - a (largely) rigid unit, which serves primarily to transmit forces and moments between the landing gear, the lifting units, the control unit and the payload.

The shoring 3 consists of a first embodiment (variant 1 ) essentially of two crossed tubes 6 and 7 made of carbon fiber reinforced plastic of dimension 8 × 0.5 mm, with a single hinge 60 are connected with a vertical axis of rotation. The helicopter 30 So it's in two assemblies 35 divided. The first assembly includes pipe 6 , the two lifting units connected to it 40 , the control unit 4 and the payload 5 , The second assembly consists of the tube 7 and the other two lifting units 40 ,

The 5 and 6 show details of the swivel ( 60 ) in the unfolded position. pipe 7 is on the journal 11 rotatable and low backlash. The pin 11 is with tube 6 firmly connected. It consists of carbon fiber plastic. From the control unit 4 lead two flexible, multi-core cable 70 in the pipe 7 , and from there to the two at Rohr 7 mounted lifting units 40 , The cables can follow the pivotal movement of the joint harmless. The swivel angle is 85 degrees. The hinge is unfolded with a magnet as a stop 9 locked and secured.

Alternatively, instead of the cable 70 electrical contacts are provided as electrical connections of the modules. These can be at the ready 9 be integrated.

3 shows the helicopter in the folded state. This situation is achieved by movement in the joint and by turning the rotors in certain positions. The dimensions in the y and z directions are particularly small (y ₂ = 50 mm, z ₂ = z ₁ = 70 mm). The helicopter can thereby z. B. in a slim tube (diameter about 80, length 950 mm) are stowed. The length x of the folded aircraft can be achieved by using rotors with a single rotor blade 8th be reduced to about 630 mm ( 4 , Variant 2 ). The same can be achieved with two-bladed rotors if the leaves are made foldable (increased effort). The rotors can also be disassembled by the lifting units to reduce (further) the dimensions.

Special advantages of the variants 1 and 2 are the simple structure (only one joint - extra weight about 2 g) and the quick, easy handling: collapse or unfolding in just about 3 seconds without tools.

After the 7 and 8th (Variants 3 and 4 ), the dimensions can be further reduced. Differences to the variants 1 and 2 : Pipe 6 is divided into the two outriggers 13 and 14 , Pipe 7 in the outrigger 15 and 16 ( 9 ). Thus, four modules are connected via three joints. The pipes 14 . 15 and 16 are on the common journal 11 rotatably mounted. The axes of rotation of all joints lie on a vertical axis. The cross-bores of the pipes used for storage 14 to 16 can with ver be provided wear-resistant sockets. The tubes may be reinforced in the area of storage in order to better isolate bearing forces. Loud 9 For this purpose balsa wood stoppers are provided (shown hatched), which can be soaked with thin adhesive for further reinforcement.

Also in this joint construction stops are provided (in 9 not shown). The pipes 13 to 16 can also be mechanically coupled so far that when moving from only two articulated assemblies, the others automatically follow (ease of use).

The Greater weight of the pictured joint design with three joints (across from the variant with only one joint) with about 6 g still in one very cheap Area.

The largest dimension (350 mm) of the folded helicopter after 8th is smaller than the rotor diameter (380 mm), although the rotors are rigid and can not be separated from the lifting units. The aircraft is so small that it can easily be stored in a small (hand) bag.

Interesting is also the option, the helicopter only about half as large as the to build shown examples (ie approx. 500 mm total size). The container for the folded helicopter can in this case to the size of a Spectacle cases (175 mm × 50 mm × 35 mm) can be reduced. Thus, the aircraft fits comfortably in a jacket or Coat pocket.

Further embodiments of the invention are shown schematically in the following tables. Note to the 10 to 25 : The axes of rotation are depicted as bold lines in the transverse views and as thick points in the front views.

Variants with swivel joints with axes of rotation in z-direction:

Variants with swivel joints with axes of rotation in x- and y-direction:

Further Variants arise by rotation of the axes of rotation about the z-axis.

Variants with sliding joints:

Both 26 to 29 the jibs of the shoring are telescopically variable in length. Both 30 and 31 they are axially displaceable against a central part.

There are also combinations of different joint types on an aircraft possible. Which of the numerous variants is to be preferred in individual cases, depends on geometric details, including the Geometry of the payload and its installation options.

In order to further reduce transport dimensions, the possibility of "nesting" of components in the folded state comes into consideration. So z. B. the dimension y ₅ after 8th even further reduced when the outriggers 13 to 16 be designed differently long. The booms can then be further pushed together. The same can be done with a skillful height graduation of the lifting units 40 to reach.

1

rotor

2

electric motor

3

shoring

4

headquarters control unit

5

payload

6

pipe (along)

7

pipe (Transverse)

8th

rotor blade

9

attack

10

stilt leg

11

pivot

12

counterweight

13

boom (Front)

14

boom (Rear)

15

boom (right)

16

boom (Left)

30

helicopter

35

module (of the helicopter)

40

lifting unit

60

joint

70

electrical management

Claims (37)

Helicopter ( 30 ) with three or more lifting units ( 40 ) each having at least one rotor ( 1 ) and at least one rotor ( 1 ) driving electric motor ( 2 ), characterized in that the helicopter ( 30 ) in two or more assemblies ( 35 ) is divided, the division on the supporting framework ( 3 ) of the helicopter ( 30 ), the assemblies ( 35 ) via at least one joint ( 60 ) are mechanically connected to each other, and at least one electrical connection between assemblies ( 35 ), the electrical components of various articulated assemblies ( 35 ) electrically conductively connects. Helicopter according to claim 1, characterized in that at least one electrical connection between the assemblies ( 35 ) contains electrical contacts. Helicopter according to claim 1 or 2, characterized in that at least one electrical connection between the assemblies ( 35 ) at least one electrical line ( 70 ) contains. Helicopter according to claim 3, characterized in that at least one electrical line ( 70 ) is flexible and whose flexibility is a movement of a two assemblies ( 35 ) connecting joint ( 60 ), without the line ( 70 ) is separated. Helicopter according to claim 3 or 4, characterized in that at least one two assemblies ( 35 ) connecting, electrical line ( 70 ) includes a strand. Helicopter according to one of claims 1 to 5, characterized in that at least one two assemblies ( 35 ) connecting joint ( 60 ) has a single degree of freedom. Helicopter according to one of claims 1 to 6, characterized in that at least one two assemblies ( 35 ) connecting joint ( 60 ) allows a translatory movement. Helicopter according to one of claims 1 to 7, characterized in that at least one two assemblies ( 35 ) connecting joint ( 60 ) allows a rotational movement. Helicopter according to claim 8, characterized in that the axes of rotation of all joints ( 60 ) lie on one axis. Helicopter according to claim 8 or 9, characterized in that the axis of rotation of at least one joint ( 60 ) is approximately vertical in hovering. Helicopter according to one of claims 8 to 10, characterized in that a single joint ( 60 ) is provided with in the hover flight approximately vertical axis of rotation. Helicopter according to one of claims 8 to 10, characterized in that the axis of rotation of at least one joint ( 60 ) is approximately horizontal in hover. Helicopter according to one of claims 1 to 12, characterized in that the assemblies ( 35 ) over a maximum of three joints ( 60 ) are interconnected. Helicopter according to claim 13, characterized in that the assemblies ( 35 ) over a maximum of two joints ( 60 ) are interconnected. Helicopter according to claim 13 or 14, characterized in that the assemblies ( 35 ) via a single joint ( 60 ) are interconnected. Helicopter according to one of claims 1 to 15, characterized in that at least one joint ( 60 ) with a stop ( 9 ) is provided. Helicopter according to one of claims 1 to 16, characterized in that at least one joint ( 60 ) is designed self-locking. Helicopter according to one of claims 1 to 17, characterized in that at least one joint ( 60 ) is locked in flight. Helicopter according to one of claims 1 to 18, characterized in that at least one joint ( 60 ) contains fiber reinforced plastic. Helicopter according to one of claims 1 to 19, characterized in that at least one rotor ( 1 ) a maximum of two rotor blades ( 8th ) having. Helicopter according to claim 20, characterized in that at least one rotor ( 1 ) a single rotor blade ( 8th ) having. Helicopter according to one of claims 1 to 21, characterized in that rotor planes of rotors ( 1 ) to each other in the direction of axes of rotation of joints ( 60 ) have a distance. Helicopter according to one of claims 1 to 22, characterized in that lifting units ( 40 ) different distances to axes of rotation of joints ( 60 ) exhibit. Helicopter according to one of claims 1 to 23, characterized in that the helicopter ( 30 ) folded into a cuboid container fits whose largest edge length is smaller than the average diameter of all rotors ( 1 ). Helicopter according to one of claims 1 to 24, characterized in that the helicopter ( 30 ) folded into a cuboid container whose volume is smaller than that of a cube with the edge length of the average diameter of all rotors ( 1 ). Helicopter according to one of claims 1 to 25, characterized in that the take-off mass of the helicopter ( 40 ) does not exceed about 5 kg. Method for changing the dimensions of a helicopter ( 30 ) with three or more strokes units ( 40 ) each having at least one rotor ( 1 ) and at least one rotor ( 1 ) driving electric motor ( 2 ), containing the steps: Generation of a movement on at least one joint ( 60 ), over which parts of the framework ( 3 ) and thus assemblies ( 35 ) of the helicopter ( 30 ) are hinged together, accompanied by enlargement or reduction of at least one dimension of the helicopter ( 30 ); Rotation of at least one rotor ( 1 ) in a different position relative to the non-rotating components of the rotor ( 1 ) driving electric motor ( 2 ); Ensuring an electrical connection between electrical components of at least two different assemblies ( 35 ) of the helicopter ( 30 ), which have a joint ( 60 ) in at least one position of the joint ( 60 ). Method according to claim 27, characterized in that at least one two assemblies ( 35 ) connecting, flexible, electrical line ( 70 ) a movement of the two assemblies ( 35 ) connecting joint ( 60 ), without the line ( 70 ) is separated. Method according to claim 27 or 28, characterized in that during a movement of at least one joint ( 60 ) a position of the lifting units ( 40 ), in which all rotors ( 1 ) of the lifting units ( 40 ) can rotate freely without removing components of the helicopter ( 30 ) to be blocked. Method according to claim 29, characterized that such a position is locked. A method according to claim 29 or 30, characterized in that such a position an end position of a movement of a joint ( 60 ). Method according to one of claims 27 to 31, characterized in that during a rotation of a rotor ( 1 ) at least one outer dimension of the helicopter ( 30 ) gets smaller. Method according to one of claims 27 to 32, characterized in that during a movement of a joint ( 60 ) at least one electrical contact between at least two modules ( 35 ) is closed. Method according to one of claims 27 to 33, characterized in that during a movement of a joint ( 60 ) at least one electrical contact between at least two modules ( 35 ) is opened.