NL2035392B1

NL2035392B1 - Robotic bird

Info

Publication number: NL2035392B1
Application number: NL2035392A
Authority: NL
Inventors: Van Den Eijkel Jan-Willem
Original assignee: Cfs Greenx Holding B V
Priority date: 2023-07-14
Filing date: 2023-07-14
Publication date: 2025-01-28
Also published as: WO2025016948A1

Abstract

A robotic bird comprising: a body, wherein the body is bird—shaped, and wherein the body comprises: a head; a tail; a torso extending along a Iongitudinal axis between the head and the tail; a first wing extending in a first lateral direction away from the torso; a second wing extending in a second lateral direction away from the torso; . propulsion means configured to enable at least a forward movement of the robotic bird 10 along the longitudinal axis; a control system configured to control the propulsion means.

Description

ROBOTIC BIRD

Field of the invention

The present invention relates to a robotic bird. In particular, the present invention relates to a robotic bird comprising detachable wings and/or foldable blades.

Background of the invention

Robotic birds are e.g. used to monitor and/or influence the behavior of living birds. Often, robotic birds are designed to resemble a predatory species. Due to their convincing visual appearance and precise control over flight and hunting behavior living birds recognize them as natural adversaries. Typical non-bird drones, such as e.g. quadcopter or airplanes, prove inadequate as birds quickly grow accustomed to them. Robotic birds are especially valuable in locations such as airports, harbors, landfills, and agricultural fields, where individual or groups of birds can create significant issues.

In the state of the art various robotic birds are known. For example, EP4061709A1 discloses a robotic bird, comprising a body, extending along a longitudinal axis between a head and a tail, two fixed wings, connected to the body on opposite sides of the body, wherein each wing has a vertical cross-sectional shape along the longitudinal axis of the body, which gradually transforms in a direction away from the body, from a first shape which is convex at an upper side and concave at a lower side to a second shape which is convex at an upper side and convex at a lower side.

Summary of the invention lt is an object of the present invention to provide an improved, or at least an alternative, robotic bird. In particular, it is an object of the present invention to provide a robotic bird that may be transported easier than existing robotic birds, while ensuring a stable flight behavior.

In a first aspect of the invention a robotic bird is provided, comprising: e a body, wherein the body is bird-shaped, and wherein the body comprises: o ahead; o atail; o a torso extending along a longitudinal axis between the head and the tail; o a first wing extending in a first lateral direction away from the torso; o asecond wing extending in a second lateral direction away from the torso; e propulsion means configured to enable at least a forward movement of the robotic bird along the longitudinal axis; 1 e a control system configured to control the propulsion means.

The robotic bird is a type of unmanned aerial vehicle (UAV), wherein the body is designed to resemble a bird in its appearance. Therefore, the robotic bird comprises typical body parts such as a head, a tail, a torso and two wings. A flying movement of the robotic bird may also resemble a bird.

An angle between the first lateral direction and the longitudinal axis may be 90 degrees or less than 90 degrees. Similarly, an angle between the second lateral direction and the longitudinal axis may be 90 degrees or less than 90 degrees. Less may be understood here that the first wing and/or second wing extend slightly oblique with respect to the longitudinal axis in the direction of the tail. An angle between the first lateral direction and the second lateral direction may be 180 degrees or less than 180 degrees. To enable a forward movement of the robotic bird, the robotic bird comprises propulsion means. Typically, the propulsion means comprise one or more propellors. A propellor may be arranged at a front or tip of the head. Alternatively, or additionally, a propeller may be arranged at each of the two wings. The control system is configured to control the propulsion means. For example, the control system is configured to control a rotational speed of the propellors. The control system may comprise a communication module to send and/or receive information from a remote, which may be operated by a user. The information may comprise speed and/or steering information.

In an embodiment, the first wing is detachable with respect to the torso and/or the second wing is detachable with respect to the torso.

To improve the transportation of the robotic bird, the first wing and/or the second wing may be detached from the torso. Furthermore, the first wing may be attachable with respect to the torso, and/or the second wing may be attachable with respect to the torso. In other words, the first wing and/or the second wing may be attached to the torso in a use state of the robotic word and detached from the torso in a transportation state of the robotic bird.

In an embodiment, the first wing comprises a first main spar extending towards a root of the first wing and extending beyond the root of the first wing with a first connecting part, wherein, if the first wing is attached to the torso, the first connecting part is within the torso, and/or the second wing comprises a second main spar extending towards a root of the second wing and extending beyond the root of the second wing with a second connecting part, wherein, if the second wing is attached to the torso, the second connecting part is within the torso.

The first main spar and/or the second main spar provide stability and/or rigidity to the first and/or second wing, respectively. The first main spar and/or the second main spar may be a beam, a rod, or any other suitable element. The main spars may support the wings and/or provide structural stability. The first main spar may be within the first wing for at least 60% of its length, preferably for 2 at least 80%. Similarly, the second main spar may be within the second wing for at least 60% of its length, preferably for at least 80%. A part of the first and/or second main spar that is not within the first or second wing, respectively, and thus extends out of the first and second wing, respectively, especially beyond the root of the first and second wing, respectively, may be used for connecting the first and second wing, respectively, to the torso and is as such referred to as the first and second connecting part, respectively. At least part of the root of a wing may touch and/or connect to the torso if the wing is attached to the torso. The first connecting part is at least partly within the torso if the first wing is attached to the torso. Similarly, the second connecting part is at least partly within the torso if the second wing is attached to the torso. As a result, both the first and second connecting part are within the torso if both wings are attached, such that the first and second main spar may be connected to the torso, and/or connected to each other. Each wing may further comprise another spar. The another spar may be elongated, and may be arranged at least partly within a respective wing. The another spar may be connected to a main spar. The another spar may arranged at an angle with respect to the main spar. The angle may be between 30 and 60 degrees. In particularly, the another spar may extend from the main spar to a tip of the respective wing. For example, a first another spar may extend from the first main spar to the tip of the first wing. Similarly, a second another spar may extend from the second main spar to the tip of the second wing. The another spar may have a thickness between 1 and 3 mm, preferably around or exactly 2 mm. The another spar may be thinner than the main spar. The another spar in the wing may add an additional structural stability to the wing and to the robotic bird. The another spar may comprise carbon. in an embodiment, the robotic bird comprises a locking mechanism configured to engage, if the first wing is attached to the torso, the first connecting part and/or to engage, if the second wing is attached to the torso, the second connecting part, to prevent a movement of the first wing with respect to the torso in the first lateral direction, and/or a movement of the second wing with respect tothe torso in the second lateral direction.

The locking mechanism engages the first connecting part and/or the second connecting part.

The locking mechanism may connect to the first connecting part and/or to the second connecting part. The locking mechanism prevents, if it engages the connecting parts, that the wings may be pulled out or detached from the torso. The locking mechanism may comprise a plurality of parts that may interact with each other in order to engage the first and second connecting parts. The locking mechanism may be designed in various ways, wherein the design may in particular be adapted to the design of the connecting parts. 3 in an embodiment, the first main spar and the second main spar are rigidly connected to each other if the locking mechanism engages the first connecting part and the second connecting part.

The locking mechanism may provide, directly or indirectly, a rigid connection between the first connecting part and the second connecting part. Such rigid connection may be provided by a rigid connection between the locking mechanism and the first main spar, and simultaneously a rigid connection between the locking mechanism and the second main spar.

In an embodiment the first connecting part comprises a first hook configured to hook around part of the locking mechanism to prevent a movement of the first wing in the first lateral direction, and/or the second connecting part comprises a second hook configured to hook around part of the locking mechanism to prevent a movement of the second wing in the second lateral direction.

The first and second connecting part may comprise a hook. The first and/or second hook may alternatively also be referred to as a hook-shaped part. The first hook may be at an end of the first connecting part. The second hook may be at an end of the second connecting part. in particular, the end of the first connecting part and/or second connecting part that comprises the first and second hook, respectively, may be a free end of the first and second connecting part, i.e. the end that is facing away from the respective wing. The locking mechanism may comprise a hooking part around which the first hook and/or second hook may hook around. Said hooking part may be moveable into and out of a locking position. If the locking part is in the locking position, the first hook and the second hook hook around the hooking part comprised by the locking mechanism.

In an embodiment, the locking mechanism comprises a pin, wherein the pin is arranged to be movable into and out of a locking position, wherein the first hook hooks around the pin if the pin is in the locking position, and/or the second hook hooks around the pin if the pin is in the hooking position.

The locking part comprised by the locking mechanism may be a pin. The pin may be an elongated object. The pin may comprise two or more sub-pins, which in themselves may be elongated objects. The outline of a transverse cross section of the pin, perpendicular to the elongated direction, may have a substantially round, oval, square, rectangular, or any other shape. A provided pin or sub-pin may substantially have a shape of a cylinder, beam, or nail. The pin may comprise a metal or carbon. The pin may slide along part of the locking mechanism to move in and out of the locking position. The pin may be connected to the torso and may be moveable with respect to the torso to be able to move in and out of the locking position. Alternatively, the pin may be a loose object that may be removed from the robotic bird if the pin is out of the locking position. 4 in an embodiment, the first connecting part comprises a first hole and/or the second connecting part comprises a second hole, and wherein the locking mechanism comprises at least one pin, wherein the at least one pin is arranged to be movable into and out of a locking position, wherein the at least one pin forms a pin-hole connection with the first hole and/or the second hole, ifthe at least one pin is in the locking position, to prevent a movement of the first wing in the first lateral direction and/or to prevent a movement of the second wing in the second lateral direction.

In an embodiment, the first hole and the second hole are at least partly overlapping, or the first hole and the second hole are not overlapping and/or spaced apart. if the first hole and the second hole are overlapping, a single pin may be used, which single pin extends through both the first and second hole in order to lock the first and second connecting part. In such a case the first and second connecting part partly overlap, such that the holes thereof may also overlap. if the first hole and the second hole are spaced apart, the pin may comprise at least two sub-pins, wherein a first sub-pin forms a pin-hole connection with the first hole, and a second sub-pin forms a pin-hole connection with the second hole. The sub-pins are an integral part of one pin.

In an embodiment, the first connecting part and the second connecting part are configured to engage each other if the first wing and the second wing are attached to the torso, to at least limit a movement of the first wing in a rotational direction with respect to the longitudinal direction of the torso and/or to at least limit a movement of the second wing in a rotational direction with respect to the longitudinal direction of the torso.

In use of the robotic bird according to the invention it is preferred that the wings do not move and in particular do not rotate with respect to the torso. This may be achieved by having the first and second connecting part engage each other, which engagement limits and preferably even prevents the rotation of the wings with respect to the longitudinal direction of the torso.

The longitudinal direction may be a direction along the longitudinal axis.

In an embodiment, the first connecting part and the second connecting part are complementary shaped.

By having the first connecting part and the second connecting part complementary shaped, both parts may engage each other to limit or even prevent the rotation of one connecting part with respect to the other connecting part in a rotational direction with respect to the longitudinal direction of the torso. 5

The complementary shapes may be any suitable shapes. Practically one of the first and second connecting parts comprises a recess and the other of the first and second connecting parts comprises a projection, such that the projection of the one connecting part may be arranged in the recess of the other connecting part, thereby providing the engagement between the connecting parts. In an embodiment, the torso is arranged to engage, if the first wing is attached to the torso, a first edge of the first wing located at the root of the first wing to prevent a movement of the first wing with respect to the torso in the longitudinal direction of the torso and/or in a rotational direction with respect to the longitudinal direction of the torso, and/or engage, if the second wing is attached to the torso, a second edge at the root of the second wing to prevent a movement of the second wing with respect to the torso in the longitudinal direction of the torso and/or in a rotational direction with respect to the longitudinal direction of the torso.

In an embodiment, the torso comprises a first recess and/or first opening arranged to receive the first edge in a form-fitting manner, and/or a second recess and/or second opening arranged to receive the second edge in a form-fitting manner.

Said recesses and/or openings provide limitation to the movements of the wings. In particular, the first recess and/or first opening prevents a movement of the first wing with respect to the torso in the longitudinal direction of the torso and/or in a rotational direction with respect to the longitudinal direction of the torso. Similarly, the second recess and/or second opening prevents a movement of the second wing with respect to the torso in the longitudinal direction of the torso and/or in a rotational direction with respect to the longitudinal direction of the torso.

In an embodiment, the torso comprises limitation means for limiting an insertion depth of the first wing and/or an insertion depth of the second wing into the torso.

The torso may comprise limitations means to prevent that the wings are inserted too far into the torso. For example, the torso may comprise at a suitable position one or more vertical bars that engage with a root of a wing.

In an embodiment, the first wing comprises a first aileron, and wherein the second wing comprises a second aileron, wherein the first aileron and the second aileron are connected with the control system, wherein the control system is configured to control a movement of the robotic bird by adjusting a position of the first aileron and/or by adjusting a position of the second aileron.

By moving the ailerons up and down, the robotic may move to the right or the left, as well as possibly up and down.

In an embodiment, the propulsion means comprise: 6 e an electric motor, comprising a motor shaft, wherein the electric motor is connected to the control system, and wherein a rotation of the motor shaft is based on a motor control signal received from the control system; e a propellor, comprising: o a propellor shaft, mechanically coupled to the motor shaft, and wherein a rotation of the propellor shaft is associated with the rotation of the motor shaft; o blades, wherein the blades are mechanically coupled to the propellor shaft, and wherein a rotation of the blades is associated with the rotation of the propellor shaft.

The electric motor may be powered by a power sources, for example by a battery. The present invention is not limited to a particular type of propellor or electric motor.

In an embodiment, the blades are foldable between an unfolded state and a folded state, wherein, in the folded state of the blades, the blades are extending along the head.

The blades may be unfolded or folded. In the unfolded state the blades may rotate around the longitudinal axis, resulting in an at least partially forward movement of the robotic bird. In case the blades are in the folded state, the robotic bird may be more easily stored in e.g. a case in comparison with the blades being in the unfolded state. Furthermore, when the robotic bird is moving in the air, i.e. it is flying, it may be beneficial to have the blades in a folded state to improve a gliding of the robotic bird through the air. in an embodiment, the blades are configured to unfold into the unfolded state if a rotational speed of the propellor shaft is above a first threshold value.

The rotational speed of the propellor shaft is associated with the rotational speed of the blades. An increase of the rotational speed of the propellor shaft is associated with an increase of the rotational speed of the blades. Due to a centrifugal force, the blades unfold if the rotational speed of the propellor shaft is sufficiently high, and at least as high as the first threshold value. For example, the first threshold value may be 1000 rpm.

In an embodiment, the blades are configured to fold into the folded state if the blades engage with an object and/or due to air resistance, for example if the air resistance is above a second threshold value.

In particular the blades may be configured to fold into the folded state force associated with the engaging of the object or the air resistance is sufficiently high to overcome the centrifugal force biasing the blades to be in the unfolded state. In case the centrifugal force is zero due to the 7 propellor shaft not being driven by the electric motor, the blades may fold if the air resistance is sufficiently high, for example above the second threshold value. In case the blades engage with an object, the blades may fold into the folded position to avoid damage to the object and/or to the propulsion means, in particular to the blades themselves. in an embodiment, a height of the head is larger than a width of the head, and wherein preferably the head is shaped as a head of a peregrine falcon.

In particular the height of the head is larger than a width of the head at a small distance from the tip or front of the head towards the tail, along the longitudinal axis. The small distance may be 1 cm. The blades are configured to fold along a side wherein the blades may fold most. Since the width of the head is smaller than the height of the head, the blades are configured to fold along the sides of the head, instead of along the top and bottom of the head. The propellor may comprise two blades such that each of the blades fold along one of the two sides of the head.

In an embodiment, the robotic bird further comprises a camera placed on top or at the bottom of the head, and wherein the blades are configured to extend in the folded state along a side of the head such that the blades do not block a view of the camera.

The camera may be configured to send images, possibly via a communication module, to a user positioned remotely from the robotic bird. Alternatively or additionally, the camera may be configured to store images on a storage medium comprised by the robotic bird. Due to the shape of the head, the blades may be configured to extend in the folded state along a side of the head. By placing the camera on top of at the bottom of the head, it may be ensured that in the folded state, the blades to not block the view of the camera. in an embodiment, the robotic bird further comprises a GPS sensor configured to determine a current location of the robotic bird.

A GPS sensor may transmit, possibly via a communication module, to a user positioned remotely form the robotic bird. The GPS sensor may determine the current position of the robotic bird and may send said location to the user. The user may control a movement of the robotic bird based on the received current location of the robotic bird.

In an embodiment, the GPS sensor is connected to the control system, and wherein the control system is configured to control a movement of the robotic bird based on a GPS signal received from the GPS sensor. 8

Based on the determined current position of the robotic bird the control system may autonomously, without user intervention, control the movement of the robotic bird.

In an embodiment, the robotic bird is configured to fly autonomously based on the current location of the robotic bird and based on a desired location and/or a desired trajectory of the robotic bird. in case the desired location and/or the desired trajectory are stored in the control system, the control system may be configured to steer the robotic bird to said desired location, preferably along the desired trajectory.

In an embodiment, the first wing and the second wing comprises polystyrene, and/or the first wing and the second wing are coated with lacquer.

Besides the wings being preferably detachable and the blades being preferably foldable, also materials of component comprised by the robotic bird may enhance the portability and/or stability.

For example, the first wing and the second wing may comprise polystyrene which is a lightweight material. Additionally, the first and the second wing may be coated by preferably lacquer to improve stability and/or rigidity of the robotic bird.

In an embodiment, the first main spar and the second main spar comprise carbon.

Carbon may provide sufficient structural stability and is on the other hand relatively lightweight in comparison to alternative materials that may provide a similar structural stability, such as metals. in an embodiment, the torso comprises PA11 and/or PA12.

Said polymers or nylons may be used for 3D printing of the torso. Generally, PA11 has a higher ductility and impact resistance, whereas PA12 may be stiffer and may withstand higher temperature changes. The torso may comprise both PA11 and PA12. The PA11 and/or PA12 may be selective laser sintered PA11 and/or PA12. The torso may be thicker at the bottom part and/or belly part with respect to other torso areas, to increase impact stability during landing.

In an embodiment, the tail is V-shaped, and/or the tail comprises Kevlar and/or a coating of the tail comprises carbon. The tail may comprise an elevator. In case the tail is V-shaped the tail may comprise two elevators, each arranged on a respective side of the ‘V’. The ratio between the body and tail length may be between 1.5:1 and 2.5:1, preferably 2:1. In comparison to other robotic birds the tail of the robotic bird according to the present invention may be relatively short. An inner angle at the bottom of the robotic bird between the tail and the torso may be less than 180 degrees, preferably less than 170 degrees. l.e., the tail and the torso may not form a straight line at the 9 bottom of the robotic bird. The elevators in the tail may enable to control the robotic bird with only the elevators, such that additional ailerons arranged at the wings may not be needed to control a flying direction of the robotic bird.

The tail may be V-shaped for an improved flying stability. However, other shapes may be possible as well.

These and other aspects of the invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols designate like parts.

Brief descriptions of the drawings

Figure 1 schematically shows an embodiment of a robotic bird according to the invention in a perspective view, comprising a first wing and a second wing.

Figure 2 schematically shows the embodiment of figure 1, wherein the first wing and the second wing are detached.

Figures 3a and 3b schematically show a second embodiment of a robotic bird according to the invention in a transverse cross-sectional view, wherein figure 3b is a detail of figure 3a.

Figures 4a, 4b, 4c and 4d schematically show the second embodiment of figures 3a, 3b, wherein a locking mechanism is applied.

Figure 5 schematically shows another embodiment of a locking mechanism.

Figure 6 schematically shows yet another embodiment of a locking mechanism.

Figure 7 schematically shows an further embodiment of the robotic bird, wherein the first wing comprises a first aileron, and wherein the second wing comprises a second aileron.

Figure 8 schematically shows an embodiment of the propulsion means, comprising a propellor with blades, wherein the blades are foldable.

Figure 9 schematically shows an embodiment of the robotic bird, wherein a camera is placed on top of the head, and wherein the robotic bird further comprising a GPS sensor.

Detailed description of embodiments

In the figures, elements of the further embodiment that are substantially unchanged with respect to the first embodiment, will not be described again. Like elements retain like numbering. 10

Figure 1 schematically shows an embodiment of a robotic bird 101 according to the present invention. The body of the robotic bird 101 is bird-shaped. In this embodiment, the shape of the body of the robotic bird 101 resembles at least partly a shape of a peregrine falcon. The present invention is not limited to a particular shape of bird. However, the present invention is particular useful robotic birds resembling predatory species, as such species are often large and therefore more difficult to transport than robotic birds resembling smaller species The robotic bird 101 comprises besides the body, also propulsion means 103 and a control system 105. The body of the robotic bird further comprises a battery 107 for powering the control system 105 and the propulsion means 103.

Typically for a bird, the body of the robotic bird 101 comprises a head 109, a tail 111, a torso 113 extending along a longitudinal axis 115 between the head 109 and the tail 111, a first wing 117 extending in a first lateral direction 121 away from the torso 113, and a second wing 119 extending in a second lateral direction 123 away from the torso 113. The first wing 117 and the second wing 119 comprise polystyrene. The first 117 and second 119 wing contains for at least 90% of its total mass polystyrene. The wings may contain different materials in different embodiments. Optionally, the first wing 117 and the second wing 119 are coated with lacquer. The tail 109 in this embodiment is V-shaped. The V-shaped tail provides good flight stability. Parts of the body may comprise various materials. For example, in the current embodiment, the torso 113 comprises polymer PA11 and/or

PA12. In this embodiment, the tail 109 comprises Kevlar. Furthermore, a coating of the tail 109 comprises carbon. The propulsion means 103 are configured to enable at least a forward movement of the robotic bird 101 along the longitudinal axis 115. in this embodiment, the propulsion means 113 comprise a propellor located at the front or tip of the head 109. In different embodiments, one or more propellors may be placed at different locations, for example at the wings 117, 119. To control the propulsion means 113, a control system 105 is comprised by the robotic bird 101.

Typically, at least part of the control system 101 is placed in the torso 113, and connected with the propulsion means 103. Furthermore, the control system 101 may be wirelessly connected to a remote controller which may be operated by a user. The robotic bird 101 may comprise a cover 125 which may be opened to provide access to components inside of the robotic bird 101, such as a pin 407, 507. The first wing 117 and/or the second wing 119 may be permanently fixed to the torso 113, or may be detachable. By detaching the wings 117, 119, the robotic bird 101 is easier to transport.

The wings 117, 119 can also be attached to the robotic bird 101.

Figure 2 schematically shows an embodiment wherein the first wing 117 is detachable with respect to the torso 113 and wherein the second wing 119 is detachable with respect to the torso 113. Specifically, Figure 2 depicts a situation wherein the first wing 117 and the second wing 119 are detached and therefore are in a detached state. In case the first wing 117 and the second wing 119 11 are attached to the torso 113, which is in a use state of the robotic bird 101, the robotic bird 101 will have the appearance as the robotic bird 101 depicted in Figure 1. The torso 113 is arranged to engage, if the first wing 117 is attached to the torso 113, a first edge 201 of the first wing 117 located at the root 203 of the first wing 117 to prevent a movement of the first wing with respect to the torso 113 along the longitudinal axis 115. Furthermore, a movement in the rotational direction 207 with respect to the longitudinal axis 115 is prevented. The torso 113 is further configured to engage, if the second wing 119 is attached to the torso 113, a second edge 209 at the root 211 of the second wing 119 to prevent a movement of the second wing 119 with respect to the torso 113 along the longitudinal axis 115. Furthermore, a movement in the rotational direction 207 with respect to the longitudinal axis 115 is prevented. To achieve this, the torso 113 depicted in Figure 2 comprises a first opening 215 to receive the first edge 201 in a form-fitting manner and a second opening 217 arranged to receive the second edge 211 in a form-fitting manner. Alternatively, or additionally the torso 113 may comprise a first recess 205 arranged to receive the first edge 201 in a form-fitting manner and a second recess 213 arranged to receive the second edge 211 in a form-fitting manner.

Form-fitting refers to the recesses 205, 213 and/or opening 215, 217 being arranged to match the shape of the wings 117, 119, in particular the shape of the wings 117, 119 at the roots 203, 211. In an attached state, said form-fitting manner limits possible movements of the wings 117, 119, with respect to the torso 113. For example, the first wing 117 may only be moveable in the first lateral direction 121 if the first wing 117 is attached to the torso 113. Similarly, the second wing 119 may only be moveable in the second lateral direction 123 if the second wing 119 is attached to the torso 113. The locking mechanism 401, 501, 601 further limits or preferably prevents in use a movement of the wings 117, 119 in the lateral directions 121, 123. A further advantage of the torso 113 receiving the wings 117, 119 in a form fitting manner is that it is prevented that water may enter the torso 113 at the wings 117,119. The wings 117, 119 may move inward of the torso 113 until such inward movement is stopped or prevented by limitation means 219. Therefore, the torso 113 comprises limitation means 219 for limiting an insertion depth of the first wing 117 and/or an insertion depth of the second wing 119 into the torso 113.

Figures 3a and 3b show a second embodiment of a robotic bird according to the invention in a transverse cross-sectional view, wherein figure 3b is a detail of figure 3a. The transverse cross- sectional view in Figure 3a includes a transverse cross-sectional view of parts of the wings. In particular, Figure 3b provides a zoomed in view of part of Figure 3a. The first wing 117 comprises a first main spar 301 extending towards a root 203 of the first wing 117 and extending beyond the root 203 of the first wing 117 with a first connecting part 303. Similarly, the second wing 119 comprises a second main spar 305 extending towards a root 211 of the second wing 119 and extending beyond 12 the root 211 of the second wing with a second connecting part 307. The first main spar and the second main spar are in this embodiment made of carbon. The thickness of both spars is in this embodiment 15 mm. However, in other embodiments the thickness may be different, for example between 5 and 20 mm. The main spar may be substantially as thick as the wing. If the first wing 117 is attached to the torso 113, the root 203 of the first wing 117 is at or inside of the torso 113.

Consequently, if the first wing 117 is attached to the torso 113, the first connecting part 303 is within the torso 113. Similarly, if the second wing 119 is attached to the torso 113, the second connecting part 307 is within the torso 113. If the first connecting part 303 engages the second connecting part 307, a hole 309 is created or provided. The first main spar 301 and the second main spar comprise carbon 305. Generally, the first main spar 301 and the second main spar 305 are sufficient to provide sufficient stability to the robotic bird 101, and in particular to the wings 117, 119. However, in embodiments of the invention, additional spars may be present. It is noted that in the embodiment of figures 3a and 3b the wings 117, 119 are not inserted into any opening of the torso 113. instead, in this embodiment the roots 203, 211 of the first and second wing 117, 119, respectively, abut the torso 113. However, it will be clear for the skilled person that alternatively the roots 203, 211 of the first and second wing 117, 119, respectively may be inserted into a respective opening or recess of the torso 113,

Figures 4a, 4b, 4c and 4d show an embodiment of a locking mechanism 401. The locking mechanism comprises a pin 407. The pin 407 is moveable along longitudinal direction axis 115, as is particularly shown in Figure 4d. The locking mechanism 401 is configured to engage, if the first wing 117 is attached to the torso 113, the first connecting part 303 and/or to engage, if the second wing 119 is attached to the torso 113, the second connecting part 307. By doing so, the locking mechanism 401 prevents a movement of the first wing 117 with respect to the torso in the first lateral direction 121. The locking mechanism furthermore prevents a movement of the second wing 119 with respect to the torso in the second lateral direction 123. The first main spar 301 and the second main spar 305 are rigidly connected if the locking mechanism 401 engages the first connecting part 303 and the second connecting part 307. In this embodiment, the first connecting part 303 comprises a first hook 403 configured to hook around part of the locking mechanism 401 to prevent a movement of the first wing 117 in the first lateral direction 121. Similarly, the second connecting part 307 comprises a second hook 405 configured to hook around part of the locking mechanism 401 to prevent a movement of the second wing 119 in the second lateral direction 123. The locking mechanism comprises a pin 407, wherein the pin 407 is arranged to be movable into and out of a locking position, wherein the first hook 403 hooks around the pin 407 if the pin 407 is in the locking position and the second hook 405 hooks around the pin 407 if the pin 407 is in the hooking position. To 13 arrange the pin 407 in the locking position, the pin 407 is moved through the hole 309. In particular,

Figure 4a depicts the pin 407 not being in the locking position, i.e. hooks 403, 405 do not hook around the pin 407. Figure 4b depicts the pin 407 in the locking position, wherein the hooks 403, 405 hook around the pin 407. Figure 4c shows the pin 407 from the same perspective as the perspectives in Figures 4a and 4b. Figure 4d shows the pin 407 in a different perspective wherein it is clear that the pin 407 is an elongated object. it is noted that in particular in this embodiment hooking around occurs by first bringing the first connecting part 303 and second connecting part 307 into a position wherein the connecting parts 303, 307 engage each other and as a next step bringing the pin 407 into the locking position. The pin 407 is shown as a loose object, i.e. as an object that can be removed from the torso 113. However, it is also possible that the pin 407 is connected to a rail or guiding system that provides an easy alignment of the pin 407 with the hole 309. In another embodiment, the pin 407 may have a head such that the complete pin 407 cannot be pushed through the hole 309.

Figure 5 schematically shows another embodiment of a locking mechanism 501. in this alternative embodiment the first connecting 303 part comprises a first hole 503 and the second connecting part 307 comprises a second hole 505. The locking mechanism 501 comprises in this embodiment one pin 507, wherein the pin 507 is arranged to be movable into and out of a locking position, wherein the pin 507 forms a pin-hole connection with the first hole 503 and the second hole 505, if the pin 507 is in the locking position, to prevent a movement of the first wing 117 in the first lateral direction 121 and to prevent a movement of the second wing 119 in the second lateral direction 123. In the embodiment of Figure 5, the first hole 503 and the second hole 505 are not overlapping and are spaced apart. Pin 507 comprises two sub-pins 507a. 507b, i.e., two elongated parts. The first sub-pin 507a is configured to form a pin-hole connection with the first hole 501, and the second sub-pin 507b is configured to form a pin-hole connection with the second hole 505.

Alternatively, the first hole 503 and the second hole 505 are at least partly overlapping, i.e. aligned, such that one pin may be sufficient to form a pin-hole connection with both holes. In such an embodiment one pin, or one sub-pin thereof, may be inserted into both holes.

Figure 6 schematically shows another embodiment of the robotic bird. In particular, embodiments of a locking mechanism 601 and of the main spars are shown. The first wing 117 comprises, besides first and second main spars, a first secondary spar 609 and a second secondary spar 611, each comprising a respective connecting part. The working principles of locking the first secondary connecting part 609a of the first secondary spar 609 and the second secondary connecting part 611a of the second secondary spar 611 follow, mutatis mutandis, the working principles of locking the first spar 301 comprising the first connecting part 303 and the second spar 305 14 comprising the second connecting part 307. It is noted that the first connecting 303 part comprises a first hole 603 and the second connecting part 307 comprises a second hole 605. The locking mechanism 601 comprises in this embodiment two pins 607, 613. In the embodiment of Figure 6, the first hole 603 and the second hole 605 overlap if both wings 117 and 119 are attached to the torso 113, such that a first pin 607 of the two pins 607, 613 can form a pin-hole connection with the first hole 603 and with the second hole 605. Likewise, the second pin 613 can form a pin-hole connection with the overlapping holes 613, 615 of the connecting parts of the first secondary spar 609 and second secondary spar 611. If pins 607, 613 are in the locking position a movement of the first wing 117 in the first lateral direction 121 and a movement of the second wing 119 in the second lateral direction 123 is limited and preferably prevented. The locking position refers to a situation in which pins 607, 613 extend through the respective holes of the connecting parts of the spars. Connecting parts 303 and 307 are complementary shaped. The hook-shaped end part or projection of the first connecting part 303 is arranged to fit in the recess of the second connecting part 307. Similarly, the hook-shaped end part or projection of the second connecting part 307 is arranged to fit in the recess of the first connecting part 303. In contrast to embodiments shown in Figures 3a, 3b, 4a, 4b and 5, wherein the pin 407, 507 moves substantially horizontal in and out of the locking position, the embodiment shown in Figure 6 shows a locking mechanism 601 wherein pins 607, 613 move substantially vertical in and out of the locking position.

As is shown in Figures 3a, 3b, 4a, 4b, 4c, 4d, 5 and 6, the first connecting part 303 and the second connecting part 307 are configured to engage each other if the first wing 117 and the second wing 119 are attached to the torso 113, to prevent a movement of the first wing 117 in a rotational direction 207 with respect to the longitudinal direction 115 of the torso 113 and/or to prevent a movement of the second wing 119 in a rotational direction 207 with respect to the longitudinal direction 115 of the torso 113. This may for example be achieved by designing the first connecting part 303 and the second connecting part 307 such that these are complementary shaped. As is in particular visible in for example figure 4a, because of the complementary shape of the first connecting part 303 and the second connecting part 307 the connecting parts 303, 307 hook into each other, such that rotation with respect or about the longitudinal direction 115 of the torso 113 is prevented. The shapes as shown are only exemplary, other shapes may provide this advantage as well

Figure 7 schematically shows an embodiment wherein the first wing 117 comprises a first aileron 701, and wherein the second wing 119 comprises a second aileron 703. The first aileron 701 and the second aileron 703 are connected 705 with the control system 105, wherein the control 15 system 105 is configured to control a movement of the robotic bird 101 by adjusting a position of the first aileron 701 and/or by adjusting a position of the second aileron 703.

Figure 8 schematically shows an embodiment of the propulsion means 103. In Figure 8, the propulsion means 103 comprise an electric motor 801, comprising a motor shaft, wherein the electric motor is connected to the control system 105. A rotation of the motor shaft is based on a motor control signal received from the control system 105. The propulsion means further comprises a propellor 803, comprising a propellor shaft 805, mechanically coupled to the motor shaft, and wherein a rotation of the propellor shaft 805 is associated with the rotation of the motor shaft. The propellor 803 further comprises blades 807, wherein the blades 807 are mechanically coupled to the propellor shaft 805, and wherein a rotation of the blades 807 is associated with the rotation of the propellor shaft 805. The blades 807 are foldable between an unfolded state 809 and a folded state 811, wherein, in the folded state 811 of the blades 807, the blades 807 are extending along the head 109. in particular, the blades 807 are configured to unfold into the unfolded state 809 if a rotational speed of the propellor shaft 805 is above a first threshold value. In the unfolded state the blades can rotate around the longitudinal axis, resulting in an at least partially forward movement of the robotic bird. In case the blades are in the folded state, the robotic bird can be stored easily. Furthermore, when the robotic bird is moving in the air, i.e. it is flying, it is beneficial to have the blades in a folded state to improve a gliding of the robotic bird through the air. Furthermore, the blades 807 are configured to fold into the folded state 811 if the blades 807 engage with an object and/or due to air resistance, for example if the air resistance is above a second threshold value. In particular the blades are configured to fold into the folded state if a force associated with the engaging of the object or the air resistance is sufficiently high to overcome the centrifugal force biasing the blades to be in the unfolded state. In case the centrifugal force is zero due to the propellor shaft not being driven by the electric motor, the blades fold if the air resistance is sufficiently high, for example above the second threshold value. In case the blades engage with an object, the blades fold into the folded position to avoid damage to the object and/or to the propulsion means, in particular to the blades themselves,

Figure 9 schematically shows the head 109 wherein a camera 901 is placed on top of the head 109. The blades 807 are configured to extend in the folded state 811 along a side of the head 109 such that the blades 807 do not block a view of the camera 901. See the description of Figure 8 on details of the folding of the blades 807. The robotic bird 101 also comprising a GPS sensor 903 configured to determine a current location of the robotic bird 101. The GPS sensor 903 is connected 905 to the control system 105. The control system 105 is configured to control a movement of the robotic bird 101 based on a GPS signal received from the GPS sensor 903. The robotic bird 101 is 16 configured to fly autonomously based on the current location of the robotic bird 101 and based on a desired location and/or a desired trajectory of the robotic bird 101.

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as basis for the claims and as representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention.

The terms "a" or "an", as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language, not excluding other elements or steps). Any reference signs in the claims should not be construed as limiting the scope of the claims or the invention.

The mere fact that certain measures are recited in mutually different dependent claims does not indicate that combination of these measures cannot be used to advantage. 17

Claims

Conclusions

1. A robotic bird comprising: e a body, the body being bird-shaped, and the body comprising: o a head; o a tail; o a torso extending along a longitudinal axis between the head and the tail; o a first wing extending in a first lateral direction from the torso; o a second wing extending in a second lateral direction from the torso; e propulsion means adapted to enable at least a forward movement of the robotic bird along the longitudinal axis; e a control system adapted to control the propulsion means.

2. Robot bird according to claim 1, wherein the first wing is detachable from the fuselage and/or wherein the second wing is detachable from the fuselage.

3. A robotic bird according to any preceding claim, wherein e the first wing comprises a first main spar extending to a root of the first wing and extending beyond the root of the first wing with a first connecting portion, wherein, when the first wing is attached to the fuselage, the first connecting portion is located within the fuselage; and/or e the second wing comprises a second main spar extending to a root of the second wing and extending beyond the root of the second wing with a second connecting portion, wherein, when the second wing is attached to the fuselage, the second connecting portion is located within the fuselage.

4. A robotic bird according to claim 3, comprising a locking mechanism adapted to engage, if the first wing is attached to the fuselage, the first connecting part and/or engage, if the second wing is attached to the fuselage, the second connecting part, for preventing: e. a movement of the first wing relative to the fuselage in the first lateral direction; and/or e. a movement of the second wing relative to the fuselage in the second lateral direction. 18

5. The robotic bird of claim 4, wherein the first main spar and the second main spar are rigidly connected to each other when the locking mechanism engages the first connecting part and the second connecting part.

6. A robot bird according to claim 4 or 5, wherein: e the first connecting portion comprises a first hook adapted to hook around a portion of the locking mechanism to prevent the first wing from moving in the first lateral direction; and/or e the second connecting portion comprises a second hook adapted to hook around a portion of the locking mechanism to prevent the second wing from moving in the second lateral direction.

7. The robotic bird of claim 6, wherein the locking mechanism comprises a pin, the pin being adapted to be moved into and out of a locking position, wherein: e the first hook engages the pin when the pin is in the locking position; and/or e the second hook engages the pin when the pin is in the locking position.

8. A robot bird according to claim 4 or 5, wherein the first connecting part comprises a first hole and/or the second connecting part comprises a second hole, and wherein the locking mechanism comprises at least one pin, the at least one pin being adapted to be moved into and out of a locking position, the at least one pin forming a pin-hole connection with the first hole and/or the second hole when the at least one pin is in the locking position to prevent movement of the first wing in the first lateral direction and/or movement of the second wing in the second lateral direction.

9. A robotic bird according to claim 8, wherein: e the first hole and the second hole at least partially overlap; or e the first hole and the second hole do not overlap and/or are spaced apart.

10. A robotic bird according to claim 10, wherein the first connecting part and the second connecting part are adapted to engage each other when the first wing and the second wing are attached to the fuselage, to at least restrict a movement of the first wing in a rotational direction relative to the longitudinal direction of the fuselage and/or to at least restrict a movement of the second wing in a rotational direction relative to the longitudinal direction of the fuselage.

11. Robot bird according to one or more of claims 3 to 10, wherein the first connecting part and the second connecting part have complementary shapes.

12. A robotic bird according to any one or more of the preceding claims, wherein the fuselage is adapted to: e. engage, if the first wing is attached to the fuselage, a first edge of the first wing at the root of the first wing to prevent the first wing from moving relative to the fuselage in the longitudinal direction of the fuselage and/or in a rotational direction relative to the longitudinal direction of the fuselage; and/or e. engage, if the second wing is attached to the fuselage, a second edge of the second wing at the root of the second wing to prevent the second wing from moving relative to the fuselage in the longitudinal direction of the fuselage and/or in a rotational direction relative to the longitudinal direction of the fuselage.

13. Robot bird according to claim 12, wherein the body comprises: e a first recess and/or first opening adapted to receive the first edge in a form-fitting manner; and/or e a second recess and/or second opening adapted to receive the second edge in a form-fitting manner.

14. Robot bird according to one or more of the preceding claims, wherein the fuselage comprises limiting means for limiting an insertion depth of the first wing and/or an insertion depth of the second wing in the fuselage.

15. A robotic bird according to any one or more of the preceding claims, wherein the first wing comprises a first aileron, and wherein the second wing comprises a second aileron, wherein the first aileron and the second aileron are coupled to the control system, wherein the control system is adapted to control a movement of the robotic bird by adjusting a position of the first aileron and/or a position of the second aileron.

16. A robotic bird according to any preceding claim, wherein the propulsion means comprise: e an electric motor having a motor shaft, wherein the electric motor is coupled to the control system and wherein a rotation of the motor shaft is based on a motor control signal received from the control system; e a propeller, comprising: o a propeller shaft, mechanically coupled to the motor shaft, and wherein the rotation of the propeller shaft is related to the rotation of the motor shaft; o blades, wherein the blades are mechanically coupled to the propeller shaft and wherein the rotation of the blades is related to the rotation of the propeller shaft.

17. A robotic bird according to claim 16, wherein the blades are foldable between an unfolded and a folded state, the blades extending along the head in the folded state.

18. The robotic bird of claim 17, wherein the blades are configured to unfold to the unfolded state when a rotational speed of the propeller shaft is higher than a first threshold value.

19. A robotic bird according to claim 17 or 18, wherein the blades are adapted to fold to the folded position when the blades come into contact with an object and/or as a result of air resistance, for example when the air resistance is above a second threshold value.

20. A robotic bird according to any one or more of the preceding claims, wherein a height of the head is greater than a width of the head, and wherein the head preferably has the shape of a peregrine falcon head.

21. A robotic bird according to any one of claims 16 to 20, further comprising a camera mounted above or below the head, and wherein the blades are arranged to extend along one side of the head in the folded state, such that the blades do not block the view of the camera.

22. Robot bird according to one or more of the preceding claims, further comprising a GPS sensor adapted to determine a current location of the robot bird.

23. Robot bird according to claim 22, wherein the GPS sensor is coupled to the control system, and wherein the control system is arranged to control a movement of the robot bird based on a GPS signal received from the GPS sensor.

24. A robotic bird according to claim 23, wherein the robotic bird is configured to fly autonomously based on the current location of the robotic bird and on a desired location and/or a desired trajectory of the robotic bird.

25. Robot bird according to one or more of the preceding claims, wherein the first wing and the second wing comprise polystyrene and/or the first wing and the second wing are provided with a lacquer layer. 21

26. A robotic bird according to any one of claims 3 to 25, wherein the first main spar and the second main spar comprise carbon.

27. Robot bird according to one or more of the preceding claims, wherein the torso comprises PA11 and/or PA12.

28. A robotic bird according to any preceding claim, wherein the tail is V-shaped, and/or wherein the tail comprises Kevlar and/or wherein a coating of the tail comprises carbon. 22