DE102005020593A1 - Unmanned observation helicopter has three or more rotors and a variable attitude camera - Google Patents

Abstract

An unmanned helicopter has three or more thrusters each with a rotor and with no tail rotor. The rotors are electrically powered and the remote control aircraft is fitted with a tilt mounted camera. The camera can be tilted into any suitable direction, e.g. forward flight, vertical hovering etc.

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 win in airborne observation (Observation from the air, extraction of optical information from an aircraft from) increasingly important. It dominates the classic embodiment with a main rotor, primarily for lift generation, and a Tail rotor for the torque compensation.

disadvantage this concept: about 20% of the drive power will be for the tail rotor needed and do not stand for the buoyancy available (reduced energy efficiency). Furthermore, the mechanics of the control is relative costly and complicated (collective & cyclic pitch, stabilization systems Etc.). Furthermore feature Helicopters of this type over a rather low flight stability.

at the propulsion technology of helicopters for airborne observation You can find the most common internal combustion engines. The electric drive is on the rise, however. Some advantages: quiet, reliable, weather-independent operating behavior, fine controllability, low vibration. The trend towards electric drive is forced by the continuous development of electrical energy storage, towards ever higher Energy and power density.

nevertheless is far from reaching the level of fossil fuels here, therefore the energetic efficiency in the development of electric helicopters always a big one Role plays to sufficiently long flight times and sufficient payloads to achieve. Above all, consistent lightweight construction is important.

to Obtaining the image information will be in the airborne observation Cameras of different types used. High picture quality was so far associated with relatively high weight, which prohibited the use in particularly compact helicopters. With the progressive miniaturization of camera technology can also this field of application will be tapped.

The Practicality of helicopters for airborne observation depends essentially on the type of flight guidance from. Two approaches So far, the focus has been on:

a) Manual control on sight (like model helicopter)

One Pilot standing on the ground sees and assesses attitude and movement of the helicopter and controls the device manually with a remote control transmitter.

Advantages:

• • Relative low technical effort
• • Great variability in the Flight movements - fast changes possible. Also sudden Obstacles can be avoided. Target tracking possible.
• • Fast Commissioning (no flight planning at a ground station)

Disadvantage:

• • Difficult service It requires special flying skills, which severely restricts the users of this type of control. difficulties Above all, the detection of the attitude as well as the sense-corrective activity the control functions in different flight situations. flies the helicopter z. B. on the pilot, are "reversed right and left": Controls the pilot to the right, the helicopter flies as seen from the pilot Left.
• • Range of application is limited The range is limited by the visibility, in which the attitude can still be reliably detected. It is depending on the size and geometry of the helicopter only about 50 to several hundred meters, at üb Overall dimensions of about 0.5 to about 3 m. An interruption of the line of sight usually leads to a crash after a short time, because necessary tax corrections do not occur. For the airborne observation in urban terrain (between buildings, vegetation) therefore only conditionally suitable (line of sight interrupted more often).

b) Automatic flight guidance

Of the Flight is at a ground station, z. A special computer, planned. For this purpose, path coordinates are typically specified, the the aircraft subsequently without manual control interventions automatically.

Advantages:

• • None flying skills required
• • Works also without line of sight

Disadvantage:

• • loss of time until use by previous flight planning
• • higher technical effort, expensive
• • (Yet) rather larger helicopters reserved (elaborate, heavier technology needed higher Payload)
• • low variability in the flight movements - no fast changes possible. A new route requires new time-consuming inputs. obstacles Dodge hardly possible. Too inflexible for target tracking. For the airborne Observation in urban terrain - between Obstacles - therefore poorly suited.
• • Mobility of the operator limited by bulky ground station.

One central problem of airborne Observation is the orientation of the camera on the observed Target object (scenery, building, Vehicle, human, etc.). With cameras mounted rigidly on the helicopter is the desired one Picture adjustment often not possible. Depending on the flight situation wishes you look at a different camera orientation. Particularly tricky is the Tracking of moving targets.

Of the Invention is based on the object, an improved preferred manually remotely controlled, electrically driven, easily manageable and energy efficient helicopters for airborne observation, where the visibility is not limiting, the all-round view including Looking down allows and for the observation in urban terrain is suitable for the pursuit of moving goals. The invention is also the task an improved method for airborne observation provide.

Short outline the invention

According to the invention Task solved with an unmanned, radio controlled, airborne observation provided helicopter with three or more lifting units, respectively at least one rotor and at least one rotor driving the Electric motor, with at least one remote controlled helicopter pivotable camera is provided with a transmitter for radio transmission the camera pictures.

The Pivotability of a camera can be designed differently. A camera may preferably pivot about an axis on the helicopter be appropriate, the approximate parallel to the transverse axis of the helicopter. The optical axis a camera (axis of the camera optics, shooting direction) can in one Camera position in the hover of the helicopter approximately lie horizontally, z. For example the camera view to the front ("cockpit view"). The optical axis can be approximately parallel in a camera position to the longitudinal axis of the helicopter. The camera can preferably be pivoted in such a way accomplished be that the optical axis in a camera position down obliquely is directed, or vertically downwards.

During the pivoting movement of a camera different degrees of freedom can be used. Or even a single one.

To a further embodiment According to the invention, a camera may be a so-called board camera or include such. Here is the camera optics directly a (small) evaluation electronics (board) connected - a compact Lightweight construction.

Further Is it possible, a vibration-proof camera to attach the helicopter to for example, image blurs to prevent by mechanical vibrations.

at The mechanics for panning a camera are many design variants. The swivel mechanism may include a rowing machine. The rotation axis the output of a rowing machine can simultaneously also a rotation axis represent a pivoting movement of a camera. The storage of the The output of a rowing machine and the bearing of the swivel mechanism of a camera can be identical be. A camera can be mounted on the output of a rowing machine be.

It can at least two cameras be provided on the helicopter. The optical Axes of both cameras can approximately be oriented in the same direction and the pivoting movements of both cameras can coupled, z. B. logical, electrical or mechanical. The two Cameras can Furthermore, be arranged at a distance of 5 cm to 50 cm, preferably at a distance of 7 cm to 20 cm.

For transmission The camera images to the viewer, there are various options. According to another embodiment the invention can for two cameras each one transmitter for wireless transmission of the camera images be provided. With that you can the picture information for get each camera separately to the ground, received there separately and provided to a viewer as a three-dimensional image.

Weight and size of the helicopter can vary. Preferably a take-off mass is below about 5 kg, more preferably below about 1 kg. The largest dimensions may preferably be below about 1.2 m.

• • Ubertragung der Kamerabilder per Funk zum Boden;
• • Darstellen der Kamerabilder mit einem bildgebenden System im Blickfeld eines Betrachters, z. B. einer speziellen Brille;
• • Anfliegen eines zu beobachtenden Zielobjekts mithilfe von Kamerabildern; und
• • Ausrichten wenigstens einer ferngesteuert schwenkbaren Kamera auf ein Zielobjekt per Fernsteuerung.

The invention further provides a method for airborne observation using a radio-controlled helicopter with three or more lifting units each having at least one rotor and at least one electric motor driving the rotor. The method is characterized by the following steps:

• • transmission of the camera images by radio to the ground;
• • Display the camera images with an imaging system in the field of view of a viewer, eg. B. a special glasses;
• • approaching a target object to be observed using camera images; and
• • Aligning at least one remote-controlled swivel camera to a target object remotely.

The camera images of two displayed by an imaging system Cameras can create a three-dimensional image impression in the viewer.

To a first embodiment of the method two cameras are aligned together on a target object.

The Method can be used in urban environment, preferably in a radius of about 1 km.

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 four-rotor helicopter with two cameras according to a first embodiment of the invention;

2 shows a longitudinal sectional view of the helicopter after 1 ;

3 shows an enlarged section of 1 ;

4 shows an enlarged section of 2 ;

5 shows a representation like 4 but with a different camera position;

6 shows a representation like 4 but with another camera position;

7 shows an enlarged section like 3 according to a second embodiment of the invention; and

8th shows a viewer of the camera images.

description preferred embodiments the invention

For airborne observation according to this Patent application is a specific type of helicopters provided namely those with three or more lifting units (so-called multi-rotor helicopters). 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 of one Lifting unit. The axes of the rotors are typically (approximately) vertical. The rotors serve primarily the lift generation - therefore the name lifting unit.

• Anmerkung: Im Beispiel laut Tabelle liegen die 4 Rotoren "auf Achse", im Ausführungsbeispiel nach 1 um 45 Grad versetzt.

Particularly noteworthy is the 4-rotor helicopter, which has system-related advantages and whose economic benefits increase, accelerated by recent developments of improved attitude stabilization techniques, which can be implemented particularly effective in this helicopter type. Among the advantages of the 4-rotor concept is the possibility of controlling all axes solely via the speed of four rigid rotors, ie without mechanics except rotating shafts, in particular without collective and cyclic rotor blade adjustment (see table below). 4-rotor helicopters can therefore be constructed very mechanically minimalist.

• Note: In the example according to the table, the 4 rotors are "on axis", in the exemplary embodiment 1 offset by 45 degrees.

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). This requirement competes with the pursuit of compact dimensions.

The 1 and 2 show a speed-controlled, 4-rotor helicopter 1 , which is suitable for aerial observation in urban terrain. The helicopter 1 comprises a total of four lifting units 2 , The lifting units 2 each have one in the embodiment zweiblättrigen rotor 3 and an electric motor driving the rotor 4 , The lifting units 2 are on a support frame 11 attached and connected by this. The shoring 11 also carries a central control unit 12 and two cameras 5 ,

In the control unit 12 integrated are two (logically separated) transmitters for the radio transmission of the camera images to the ground, a receiver for receiving the remote control signals from the ground, electronics for stabilizing the attitude and the control of the lifting units and the central power supply (battery).

The technical data of the helicopter 1 are as follows:

Rotor diameter: 380 mm power requirement (Hover): 25 W Flight time: 20 min Take-off weight: 350 G Dimensions over everything (Length, Width): 800 mm camera distance s: 130 mm

With the two cameras 5 These are board cameras. The camera optics are each directly on the board 6 attached ( 3 ), which houses the electronics belonging to the camera. Such a unit weighs only about 20 g, depending on the quality.

The board 6 turn is directly on the rotary drive 8th the rowing machine 7 (Servo) held.

The rowing machines 7 are about the vibration isolation 13 on the support frame 11 attached. The vibration isolation 13 are made of a soft, vibration-damping material. This disturbing vibrations are kept away from the cameras.

With rotation of the output 8th the rowing machine 7 is also the attached camera 5 pivoted. Thus, the camera is pivotable about an axis that is oriented parallel to the transverse axis of the helicopter. The arrangement allows depending on the position of the rotary drive 8th a camera view horizontally forward, ie in the direction of the longitudinal axis of the helicopter (cockpit view, 4 ), sloping downwards ( 5 ), or vertically downwards ( 6 ). Optionally, other camera positions are possible, for. B. Look up.

The pivot bearing of camera 5 and downforce 8th are identical. For storage of the camera 5 No effort is required because the storage with the rowing machines 7 already included. The solution is mechanically simple, low-friction and low-weight at the same time.

With the flexible electrical wires 14 are the cameras 5 and the rowing machines 7 with the central control unit 12 electrically connected. The cables are inside the shoring 11 laid.

The horizontal opening angle of the camera optics in the exemplary embodiment is 40 degrees, the vertical 30 degrees. This data becomes the viewer on the ground 9 provided a realistic cockpit view from the helicopter ("natural image").

In the embodiment, two cameras are present to the viewer 9 ( 8th ) to convey a three-dimensional impression. For this purpose, the optical axes of the two cameras are parallel, with a distance of 130 mm. The parallelism is ensured even when the cameras are rotated, because the rowing machines are moved synchronously. Both cameras thus take (almost) the same picture, but from a slightly different perspective. The viewer 9 carries an imaging system 17 at the head. The right eye of the viewer is offered the image of the right camera, the left eye of the left camera. The result is a three-dimensional image impression in the viewer, with which he can estimate distances much better. He can control the helicopter safer, especially obstacles easier to detect and avoid.

The provided in the embodiment distance of the two cameras of 130 mm is slightly larger than the human eye distance. This enhances the 3D effect over normal vision. The bigger the distance between the cameras, the easier it is to differentiate between different, larger distances. However, if the camera distance is too great, there are unpleasant "distortions" in the near vision - sometimes the 3D image impression is lost 130 mm is a good value, but other values may be useful depending on the distance of the target objects and viewing habits.

at Abandoning three-dimensional vision can be on the second camera be omitted (weight and cost savings).

optional a camera can also be provided with a housing. The housing can also surrounded several cameras. It can, for example, two cameras combined into a "stereo camera" be.

7 shows a variant of the camera pivoting mechanism. Compared to the solution 3 is a rowing machine 7 saved. Both cameras 5 are moved with a single steering machine. The cameras 5 with the boards 6 are on the pipe 16 attached and connected. The right end of the tube is at the output 8th the rowing machine 7 held, the left in the camp 15 rotatably guided. The weight of the complete swing mechanism after 7 amounts to 8 g including rowing machine ( 3 : 11 g).

The airborne observation with the presented system may look like this: the operator and the viewer 9 ( 8th ) controls the aircraft manually with a remote control transmitter on the basis of the camera images, which are constantly in real-time close to the imaging system 17 be fed. He sees the surroundings of the helicopter as if he were sitting in it. For normal flight operations, the camera is oriented horizontally (as in 4 ) or (slightly) downwards ( 5 ).

Because the camera is not tilted to the right or left, just to is an axis parallel to the transverse axis can be pivoted is the operator always in the picture, where the helicopter is in front, namely in the middle of the picture. This considerably simplifies the control.

One Control command "after for example, fly in the front always leads that the helicopter on the target object shown in the picture too moved. Control command "right" executes View of the operator always to a flight movement to "right". With the other Functions it is analog. A "reversal" from right / left or front / back does not take place.

For the look to the right and left is the whole helicopter around its vertical axis rotated (yaw function). In this way, the operator can be at any time provide a 360 ° view without the need for an additional swivel mechanism for the Camera would be required (Implementation of the minimal principle by combination of functions).

Just In this control function, the benefits of the 4-rotor helicopter come to carry. The yaw function is decoupled from the other control functions. For any control command (pitch, roll, yaw or up / down) the helicopter does not need any other control command for compensation triggered by side effects become. (The conventional helicopter, however, are such undesirable Couplings known. Example: Up / Down changes torque compensation required by tail rotor.) Also has the 4-rotor helicopter no preferential flight direction like conventional types. He can go after front / back, right / left alike. This is it is possible the helicopter at any time in such a position about its vertical axis to turn that desired Scenery in the camera image can be seen. The helicopter can do this lingering in one place (hover), forward, back or be moved to the side, with always neutral tax behavior, especially without self-acting in the direction of flight to the front. (The inclination "with the Nose to fly ahead "knows one of conventional Helicopters. Reason is the wind vane effect of tail boom and tail rotor.)

This special flight behavior of 4-Rotorenhubschraubern remains at Wind received (assuming the flow velocity at the helicopter is below the design airspeed). The hover is possible in any wind direction, without disturbing moments around the vertical axis. (Conventional helicopters are spinning more or less in the wind.) As a flight maneuver of the helicopter of the invention may be mentioned as an example: persecution of a fugitive bank robber in the city (forward flight). "Flying off" the park rows of a Parking garage with identification of the license plates (cross-flight). Circle of a target object, e.g. B. a burning building that is permanently in the picture remains (cross flight with rotation).

In the embodiment, the pivotability of the camera with only a single freedom degree, namely pivoting about a transverse axis. With this degree of freedom alone - in combination with the yaw function of the helicopter - the camera can be rotated in every possible attitude in any direction (implementation of the minimum principle by dispensing with unnecessary degrees of freedom).

Opposite the Alternative, several (rigidly mounted) cameras for different To use directions, the concept presented has with swiveling Cameras advantages in costs and weight.

The Cameras are mounted close to the helicopter (important because of inertia, Overall center of gravity and flight behavior), with virtually unlimited visibility in all relevant directions. (Only the rotor blades comb the picture at certain Camera positions.)

The Pivoting the cameras makes valuable service in flight operations. For the Cruise flight (forward), the cameras are preferably horizontal Align to the front, at high airspeed possibly to the longitudinal axis slightly upward to the "tilt" of the helicopter in the high-speed flight too compensate. Some target objects can only be viewed from above, for example, a courtyard between buildings. Here you become the cameras temporarily put in a vertical position. A cheap camera position for many Flight situations is slightly inclined downwards. You can see in the bottom Picture part of the underground (important when landing) and in the upper just the horizon (helpful for orientation).

Of the Operator controls a total of 5 functions: roll, pitch, yaw, Up / down and the swivel angle of the camera (s). These functions can be found in 2 classes are divided:

• a) Roll, pitch and up / down serve primarily the movement of the aircraft in the room.
• b) With yaw and swivel angle in the room "optically navigates "and that focused on each target object (yaw for "right-left-scroll", swivel angle for "scrolling down").

The Experience has shown that these 5 functions of a single Operators can be controlled simultaneously, especially if the two functional classes are distributed to different controls. Would be more Functions implemented (eg additional camera adjustment options) would be the Operator overwhelmed, depending on the flight task. The operability is decisively influenced by the Flight characteristics and the helicopter's control behavior. With 4-rotor helicopters have achieved the best results.

The Work of the operator may be through additional equipment and electronic Helps (advanced attitude stabilization, GPS, zoom function on cameras etc.) and be relieved.

at many uses in urban terrain allowed by the aircraft no danger, neither to persons nor to things (Vehicles, buildings, etc.). Also in this point impresses the presented in the embodiments Helicopter. The kinetic energy in a crash is small, because of the low take-off weight of only 350 g.

Also at the risk potential Due to the rotating rotors, the presented concept has advantages. 4 small rotors are less dangerous as a big one like the conventional helicopter. The respective drive power (here about 6 W) is much smaller and the rotors are much lighter (here about 7 g). Both together causes the rotors without serious Injuries can be stopped by hand. (In the conventional Helicopters, on the other hand, are at considerable risk from the main rotor out. Rotor mass and mass moment of inertia rise disproportionately with the diameter. In addition, conventional rotors often very targeted with higher Moment of inertia be designed to improve the autorotation properties. Sometimes even more Weights attached.) The hazard potential in the helicopter of the invention can be further reduced by collision protection systems (eg with on the support frame retained protective rings or protective straps on the rotors).

Conclusion: The multi-rotor helicopter according to the invention with remote-controlled swivel camera meets the requirements of a aircraft for obtaining optical information from the air in an ideal way. round visibility is possible in all directions and in every flight situation. Of the Helicopter is manageable, light, energy efficient, inexpensive, reliable, quiet and safe. It is universally applicable, even in urban areas, on the narrowest Space, between obstacles, over Crowds and inside buildings. Moving targets can be tracked become.

1

helicopter

2

lifting unit

3

rotor

4

electric motor

5

camera

6

circuit board

7

rowing machine

8th

output

9

observer

11

shoring

12

control unit

13

vibration isolation

14

electrical management

15

camp

16

pipe

17

imaging system

Claims (23)

Unmanned, radio-controlled helicopter intended for airborne observation ( 1 ) with three or more lifting units ( 2 ) each having at least one rotor ( 3 ) and at least one rotor ( 3 ) driving electric motor ( 4 ), whereby the helicopter ( 1 ) at least one remotely pivotable camera ( 5 ) is provided with a transmitter for radio transmission of the camera images. Helicopter according to claim 1, characterized in that a camera ( 5 ) pivotable about an axis on the helicopter ( 1 ) which is approximately parallel to the transverse axis of the helicopter ( 1 ) lies. Helicopter according to claim 1 or 2, characterized in that the optical axis of a camera ( 5 ) in a camera position in the hover of the helicopter ( 1 ) is arranged approximately horizontally. Helicopter according to one of claims 1 to 3, characterized in that the optical axis of a camera ( 5 ) is arranged in a camera position approximately parallel to the helicopter longitudinal axis. Helicopter according to one of claims 1 to 4, characterized in that the optical axis of a camera ( 5 ) in a camera position in the hover of the helicopter ( 1 ) is arranged obliquely downwards. Helicopter according to one of claims 1 to 5, characterized in that the optical axis of a camera ( 5 ) in a camera position in the hover of the helicopter ( 1 ) is arranged approximately vertically. Helicopter according to one of claims 1 to 6, characterized in that for the pivoting movement of a camera ( 5 ) a single degree of freedom is provided. Helicopter according to one of claims 1 to 7, characterized in that a camera ( 5 ) is a board camera or contains such. Helicopter according to one of claims 1 to 8, characterized in that a camera ( 5 ) isolated from the helicopter ( 1 ) is attached. Helicopter according to one of claims 1 to 9, characterized in that the mechanism for pivoting a camera ( 5 ) a rowing machine ( 7 ) contains. Helicopter according to claim 10, characterized in that the axis of rotation of the output ( 8th ) of a rowing machine ( 7 ) at the same time a rotation axis of a pivoting movement of a camera ( 5 ). Helicopter according to claim 10 or 11, characterized in that the bearing of the output ( 8th ) of a rowing machine ( 7 ) at the same time a bearing of the pivot mechanism 'of a camera ( 5 ). Helicopter according to one of claims 1 to 12, characterized in that a camera ( 5 ) at the output ( 8th ) of a rowing machine ( 7 ) is attached. Helicopter according to one of claims 1 to 13, characterized in that at least two cameras ( 5 ) on the helicopter ( 1 ) are provided. Helicopter according to claim 14, characterized in that the optical axes of the two cameras ( 5 ) are oriented approximately in the same direction and the pivoting movements of the two cameras ( 5 ) are coupled. Helicopter according to claim 14 or 15, characterized in that the two cameras ( 5 ) are arranged at a distance of 5 cm to 50 cm, preferably at a distance of 7 cm to 20 cm. Helicopter according to one of claims 14 to 16, characterized in that for two cameras ( 5 ) a transmitter is provided for radio transmission of the camera images. Helicopter according to one of claims 1 to 17, characterized in that the take-off mass of the helicopter ( 1 ) does not exceed about 5 kg, more preferably does not exceed about 1 kg. Helicopter according to one of claims 1 to 18, characterized in that the largest dimension of the helicopter ( 1 ) does not exceed about 1.2 m. Airborne observation method using a radio-controlled helicopter ( 1 ) with three or more lifting units ( 2 ) each having at least one rotor ( 3 ) and at least one rotor ( 3 ) driving electric motor ( 4 ), characterized by the following steps: • transmission of the camera images by radio to the ground; • Display the camera images with an imaging system ( 17 ) in the field of vision of a viewer ( 9 ); • approaching a target object to be observed using camera images; and aligning at least one remote-controlled camera ( 5 ) to a target object by remote control. Method according to claim 20, characterized in that two cameras ( 5 ) be aligned together. Method according to claim 20 or 21, characterized that the method is used in an urban environment. Method according to one of claims 20 to 22, characterized in that the helicopter ( 1 ) no more than about 1 km from the viewer ( 9 ) flies away.