WO2017141154A1

WO2017141154A1 - Retractable camera for fixed wing uav

Info

Publication number: WO2017141154A1
Application number: PCT/IB2017/050805
Authority: WO
Inventors: Ankit Mehta; Santosh MORE
Original assignee: Ideaforge Technology Pvt. Ltd.
Priority date: 2016-02-18
Filing date: 2017-02-14
Publication date: 2017-08-24
Also published as: WO2017141154A9

Abstract

Embodiments of the present disclosure relate to a belly-mounted retraction mechanism for a payload in a fixed wing UAV. The retractable payload can be a two-axis camera system designed to fit inside the aircraft fuselage cross section. The disclosed retraction mechanism is a servo driven direct link mechanism configured to drive the payload between its retracted/stowed position & projected position by pivotally moving the payload about a horizontal axis. The retraction mechanism gets mechanically locked in retracted and projected positions and can only be moved when driven by the servo thus preventing any unintended movements due to inertia or gravitational forces. The retraction mechanism further comprises a spring to bias the payload against gravitational force for smooth descent of the payload and a slider flap to close the opening when the payload is moved to deployed position.

Description

RETRACTABLE CAMERA FOR FIXED WING UAV

TECHNICAL FIELD

[0001] The present disclosure relates to retractable payloads for various platforms such as UAVs, other Aerial and ground vehicles, fixed hidden cameras, etc. In particular, the present disclosure relates to a retractable camera system that can be housed within the UAV body at zero position.

DESCRIPTION OF THE RELATED ART

[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] Unmanned aerial vehicles (UAVs) or drones as commonly known, are pilot-less airplanes controlled from a ground station using RF signals. Unmanned aerial vehicles (UAVs) have much usage such as surveillance, reconnaissance, product delivery and exploration of a designated site. UAVs may be outfitted with a functional payload, such as sensors for collecting data from the surrounding environment. Remote-controlled UAVs or drones, which include fixed-wing aircraft and rotary-wing aircraft, are also used to provide aerial imagery of otherwise inaccessible environments. It is desired that a payload dispensing system supporting imaging device be provided that is particularly suited to be mounted on an unmanned aerial vehicle and that allows the payload to be accurately dispensed from the unmanned aerial vehicle.

[0004] Weight and size are important considerations in the design of small UAVs and the vehicle design should provide sufficient functional space for the payload to operate. The design of such unmanned vehicles involves trade-offs between vehicle size, weight, payload capacity, energy consumption, and cost. The payload forms a bulk of the overall size of the belly of a fixed wing aircraft. A camera system that needs to be attached with the payload requires considerable space while performing tilt and pan rotations for imaging applications. This makes the UAV belly bulky in size. A retractable mechanism allows for a compact camera to be fitted into the UAV fuselage, while performing tilt and pan operations in the downward direction perpendicular to the UAV body and exterior to it. In some cases, existing unmanned aerial vehicle designs can be less than ideal for providing unobstructed viewing angles for a payload camera, such as when the visual space is obscured by the vehicle frame. It has become necessary to improve the structure/design and systems of UAVs and drones.

[0005] Therefore there is requirement of a retractable camera system attached with a UAV that can be in retracted position while the camera is not in use and in projected position while the camera needs to be used. The retractable camera system needs to be positioned in such a way as to provide unobstructed view when deployed for operation.

[0006] United States patent application US 20130193269 Al discloses one such camera retraction system for retracting or deploying a camera in an UAV. The disclosed system incorporates a camera payload pivotally attached to housing, a biasing member that is configured to bias the payload out of the housing and a winch attached to the payload. An elongated flexible drawing member such as a cable/rope is coupled between the housing and the winch and can be drawn by the winch to retract the payload within the housing. Alternatively when the cable is released by the winch the biasing member pivotally rotates the camera payload by 90 degrees and deploys it out of UAV in vertically downward position. However the disclosed arrangement suffers from deficiency that the cable being flexible cannot hold the camera payload rigidly in deployed and retracted positions. Moreover, it is not practically possible to provide a biasing member that can hold the camera payload with enough force to prevent unintended movements of the camera due to inertia forces encountered during landing and take-off.

[0007] Therefore there is a need in the art to provide a retraction system that can lock the camera payload in retracted and deployed position so as to prevent its unintended movements due to inertia forces especially during landing and take-off.

[0008] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

[0009] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term "about." Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0010] As used in the description herein and throughout the claims that follow, the meaning of "a," "an," and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.

[0011] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0012] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

OBJECTIVE OF INVENTION

[0013] An object of the present disclosure is to provide a retraction mechanism for a payload for various platforms such as UAVs, other Aerial and ground vehicles, fixed hidden cameras, etc.

[0014] Another object of the present disclosure is to provide a retraction mechanism based on linkages that occupy less space. [0015] Yet another object of the present disclosure is to provide a payload retraction system that mechanically gets locked in retracted and deployed positions to prevent unintended movements of the payloaddue to gravitational pull or inertia forces.

[0016] Still another object of the present disclosure is to provide a payload retraction system that allows movement only when corresponding servo is operated.

[0017] Another object of the present disclosure is to provide a retractable payload comprising a two-axis camera designed to fit inside the aircraft fuselage cross section.

[0018] Yet another object of the present disclosure is to provide a system for the camera to be oriented vertically downward during its deployed position, perpendicular to the fuselage, during flight.

[0019] Still another object of the present disclosure is to provide a retractable camera system to be housed within the UAV fuselage cross-section so that it withstands high-impact situations of landing and take-off.

SUMMARY

[0020] Aspects of the present disclosure relate to a retraction mechanism for a payload for various platforms such as UAVs, other Aerial and ground vehicles, fixed hidden cameras, etc. In particular, the present disclosure relates to a retractable payload that can be belly- mounted within a UAV body (also referred to as aircraft and the two terms used interchangeably hereinafter) at zero position.

[0021] The retractable payload may comprise a two-axis camera designed to fit inside the aircraft fuselage cross section. It is to be appreciated that while the embodiments of the disclosed retraction system have been described with reference to a camera system as pay load in a UAV, they can equally well be applied without any limitation to any other payload in any other platform such as any of the Aerial and ground vehicles, fixed hidden cameras, etc. where the payload may need to be deployed and retracted.

[0022] In particular, embodiments of the present disclosure relate to a retractable camera system/payload that can be housed at zero position within the UAV fuselage cross-section so that it can withstand high-impact situations of landing and take-off. During flight, the camera can be oriented vertically downward in a zero retracted position, perpendicular to the fuselage.

[0023] In an aspect, the two-axis camera payload with a belly mount arrangement can be designed to be as compact as possible to fit inside the aircraft fuselage cross section wherein the cross-section may be a 4-cell standard battery size to be used for aircraft operations. The payload mechanism can comprise three servos to actuate each operation of the camera payload - retraction, pan and tilt.

[0024] In an aspect, the retraction mechanism for the payload is a servo driven direct link and spring operated mechanism configured to drive the complete camera payload between its retracted/stowed position & projected position. In another aspect, the retraction mechanism can pivotally move the camera system about a horizontal axis to position the camera at 90 degrees from the stowed position and hold it thereto allow further camera operations.

[0025] In an aspect, the retraction mechanism is so designed that it is mechanically locked in retracted and projected positions and can only be moved when driven through a slot in the hinge. Thus the camera is prevented from unintended movement due to inertia or gravitational forces or any other reasons in both these positions. In an aspect, the retraction mechanism can include a servo driven pulley, a link rod, a bell crank shaped arm and a slotted hinged part. The bell crank shaped arm can incorporate two pins at its two ends. The mechanism may have a timing pulley which can move the link rod that can further drive the bell crank shaped arm through the first pin and the second pins of the arm travels in the slot of slotted hinge part so as to pivotally move the payload from retracted position to project it in the downward direction position (referred interchangeably as projected position) or retract it from projected position back to stowed/retracted position.

[0026] In an aspect, the slotted hinge part and the bell crank shaped arm are so configured that the second pin travelling in the slot of the hinge blocks any movement of the hinge in the retracted and the deployed positions. Thus the hinge can be moved only when driven by the second pin in the slot i.e. by the bell crank shaped arm (which in turn is driven by the link road and the pulley mechanism) ensuring that is the mechanism is mechanically locked in retracted & projected positions.

[0027] In an aspect, the retraction mechanism further incorporates means to close the opening space created within the fuselage where the payload rests at stowed position when the payload is moved to deployed position. The space if left open can accumulate dust and other foreign materials that can damage the payload as well as electronic components of the aircraft.

[0028] In an aspect, the means to close the opening can be a slider flap configured at the bottom face of fuselage and can be driven by a rack and pinion mechanism that slides the flap to and fro when the camera is moved from its retracted position to projected position and from retracted position to projected position. The slider mechanism can be driven by the retraction servo that drives the retraction system through a pulley belt. The servo, pulley belt and rack-pinion combination assembly can be configured to ensure precise and timely deployment of slider flap to close and open the camera system compartment when the camera gets projected and retracted respectively.

[0029] In an aspect, the camera system can incorporate servo operated pan and tilt mechanisms. In another aspect, the pan & tilt mechanisms can function only when the payload is in projected position.

[0030] In an aspect, the tilt rotation sub-system and corresponding servo can be placed on the top of the camera. Thus when the camera payload is in retracted position the tilt rotation sub-system and corresponding servo are placed longitudinally relative to the camera along the length of the aircraft. Thus the overall width of the camera tilt mechanism is saved by placing the tilt servo on top of the camera and being indirectly driven by gear mechanism instead of placing tilt servo on the side of camera as a direct driven system enabling reduction in width of the aircraft.

[0031] The servos used in both pan & tilt mechanism are high speed & high torque servos with a custom programmable digital circuit. As the standard servo rotates 0-90degrees and has custom programmable digital circuit, the servos of the invention are programmed to rotate 0-180degrees. This configuration is used for tilt mechanism, while using a gear ratio of 1 : 1.6 to achieve 0-270 degree rotation for pan rotation.

[0032] In an aspect, the pan mechanism can provide pan rotation of the camera where the camera can be rotated by 270° along a vertical pan axis. The pan mechanism can be a servo driven step-up gear mechanism and can be configured to provide 270° pan rotation to the camera as the servo gear can moves by 90°. The camera can pan 0° to +90° towards right and 0° to -180° towards left wherein 0°represents forward looking position (in the direction of flight) of the camera.

[0033] In another aspect, the present disclosure provides a stable retraction mechanism of payload, while reducing dimensions of the aircraft belly, contributing to an overall decrease in size and cost. Other features of embodiments of the present disclosure will be apparent from accompanying drawings and from detailed description that follows.

[0034] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred

embodiments, along with the accompanying drawing figures in which like numerals represent like components BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0036] FIG. 1 illustrates an exemplary view of payload in stowed position in aircraft installed at the fuselage belly in accordance with an embodiment of the present disclosure.

[0037] FIG. 2A illustrates an exemplary view of payload in projected position perpendicular to aircraft installed at the fuselage belly in accordance with an embodiment of the present disclosure.

[0038] FIG. 2B illustrates an exemplary view of rack and pinion combination assembly in accordance with an embodiment of the present disclosure.

[0039] FIG. 3 A to 3C illustrates an exemplary view of payload in projected position installed at the fuselage belly, tilted at different angles in accordance with an embodiment of the present disclosure.

[0040] FIG. 4A and FIG. 4B illustrates exemplary mechanical components that enables the payload to be in retracted position and projected position in accordance with embodiments of the present disclosure.

[0041] FIG. 5 illustrates front view of payload in projected position in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

[0042] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0043] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims. [0044] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

[0045] If the specification states a component or feature "may", "can", "could", or "might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.

[0046] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the disclosure to those of ordinary skill in the art. Moreover, all statements herein reciting embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure).

[0047] Thus, for example, it will be appreciated by those of ordinary skill in the art that the diagrams, schematics, illustrations, and the like represent conceptual views or processes illustrating systems and methods embodying this disclosure. The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing associated software. Their function may be carried out through the operation of program logic, through dedicated logic, through the interaction of program control and dedicated logic, or even manually, the particular technique being selectable by the entity implementing this disclosure. Those of ordinary skill in the art further understand that the exemplary hardware components, software, processes, methods, and/or systems described herein are for illustrative purposes and, thus, are not intended to be limited to any particular named.

[0048] Aspects of the present disclosure relate to a belly-mounted retraction mechanism for a payload such as a camera in a fixed wing UAV/aircraft. Particularly the camera can be housed in a retracted/stowed position within the UAV fuselage cross-section so that it can withstand high-impact situations of landing and take-off. During flight, using the disclosed retraction mechanism, the camera can be deployed vertically downward from its retracted/stowed position, perpendicular to the fuselage to carry out its assigned functions. [0049] In an aspect, the retraction mechanism for the payload can be a servo driven direct link and spring operated mechanism configured to drive the complete camera subsystem between its retracted/stowed position & projected position. In another aspect, the retraction mechanism can pivotally move the camera system about a horizontal axis to position the camera at 90 degrees from the stowed position and hold it therein vertically projecting position to allow further camera operations.

[0050] In an aspect, the disclosed retraction mechanism can comprise a pulley driven by a retraction servo; a link rod in operational engagement with the pulley and configured to move when the pulley is driven by the retraction servo; an bell crank shaped arm that comprises two pins, wherein the arm is configured to be driven by the link rod through the first pin; and a slotted hinge wherein the second pin of the arm engages in slot of the slotted hinge and moves the slotted hinge to pivotally move the payload by 90 degrees between the retracted and the deployed positions.

[0051] In an aspect, the slotted hinge is operable only at an angle obtained when driven by the link and pulley mechanism to ensure that the mechanism is mechanically locked in retracted & projected positions to ensure that the camera is prevented from unintended movements due to inertia or gravitational forces or any other reasons in both these positions.

[0052] In an aspect, the retraction mechanism further comprises a spring configured to bias the payload against gravitational force to counterbalance the weight of the payload during projection. Thus the spring enables smooth descent of the payload.

[0053] In an aspect, the retraction mechanism further incorporates means to close the opening space created within the fuselage where the payload rested at stowed position when the payload is moved to deployed position. The space if left open can accumulate dust and other foreign materials that can damage the payload as well as electronic components of the aircraft.

[0054] In an aspect, the means to close the opening can be a slider flap configured at the bottom face of fuselage and can be driven by a rack and pinion mechanism that slides the flap to and fro when the camera is moved from its retracted position to projected position and from projected position to retracted position. The slider mechanism can be driven by the retraction servo that drives the retraction system through a pulley belt. The servo, pulley belt and rack-pinion combination assembly can be configured to ensure precise and timely deployment of slider flap to close and open the camera system compartment when the camera gets projected and retracted respectively. [0055] The retractable payload may comprise a two-axis camera designed to fit inside the aircraft fuselage cross section. In particular, embodiments of the present disclosure relate to a retractable camera system that can be housed at zero position within the UAV fuselage cross- section so that it can withstand high-impact

[0056] During flight, the camera can be deployed vertically downward from its retracted/stowed position, perpendicular to the fuselage. In an aspect, the two-axis camera payload with a belly mount arrangement is designed to be as compact as possible to fit inside the aircraft fuselage cross section wherein the cross-section may be a 4-cell standard battery size to be used for aircraft operations. The payload can comprise three servos to actuate each operation of the camera payload - retraction, pan and tilt. In another aspect, the pan & tilt mechanisms can function only when the payload is in projected position.

[0057] In an aspect, the tilt rotation sub-system and corresponding servo can be placed on the top of the camera, instead of placing it along the frame/casing, thus saving space and simplifying the layout.

[0058] In an aspect, the pan mechanism can provide pan rotation of the camera where the camera can be rotated by 270° along a vertical pan axis. The pan mechanism can be a servo driven step-up gear mechanism and can be configured to provide 270° pan rotation to the camera as the servo gear moves by 90°. The camera can pan 0° to +90° towards right and 0° to 180° towards left wherein 0° represents front looking position (in the direction of flight) of the camera.

[0059] In an aspect, the tilt mechanism can be configured to tilt the camera by 180° along a horizontal axis by means of atilt servo driven gear mechanism. The camera tilt motion can be 0°to 180° wherein 0°represents front looking position and 180° is rear looking position (in the direction of flight) of the camera(with pan angle being 0°)

[0060] In another aspect, the present disclosure provides a stable retraction mechanism of payload, while reducing dimensions of the aircraft belly, contributing to an overall decrease in size and cost. Other features of embodiments of the present disclosure will be apparent from accompanying drawings and from detailed description that follows.

[0061] FIG. 1 illustrates an exemplary view of payload in stowed position in aircraft installed at the fuselage belly in accordance with an embodiment of the present disclosure. As shown in FIG. 1, the retractable payload of the disclosure can be a two-axis camera payload 102 with a belly mount arrangement designed to be as compact as possible to fit inside the aircraft fuselage cross section 104. The cross-section may be a 4-cell standard battery size to be used for aircraft operations. The payload mechanism can comprise three servos to actuate each operation of payload - retraction, pan and tilt.

[0062] In an embodiment, the camera payload 102 can be moved to deployed position from the stowed position shown in FIG 1 by projecting the camera payload 102 vertically down through an opening 108 on the underside of the fuselage cross section 104 by moving it pivotally along a horizontal axis by 90 degrees.

[0063] FIG. 2A illustrates an exemplary view of the camera payload 102 in vertically projected position perpendicular to aircraft fuselage belly in accordance with an embodiment of the present disclosure. The movement of the camera pay load from stowed position of FIG. 1 to deployed position of FIG. 2A or vice versa can be achieved by a retraction mechanism. In an aspect, the retraction mechanism for the payload can be a servo driven direct link and spring operated mechanism configured to drive the complete camera payload 102 between its retracted/stowed position & projected position wherein the retraction mechanism can pivotally move the camera payload 102 about a horizontal axis to position the camera at 90 degrees from the stowed position projecting vertically down from the bottom of the fuselage of the aircraft and hold it thereto allow further camera operations.

[0064] In an embodiment, the disclosed retraction mechanism can comprise a servo drive (also referred to as retraction servo) 202, a pulley 204 driven by the retraction servo 202, a link rod 210 in operational engagement with the pulley 204 and configured to move when the pulley 204 is driven by the retraction servo 202; a bell crank shaped arm (also referred to as bell crank or arm and the terms used interchangeably) comprising two pins (not shown) wherein the arm is configured to be driven by the link rod 210 engaging with the arm through the first pin; and a slotted hinge wherein the second of the two pins of the arm engages in slot of the slotted hinge and move the slotted hinge (not shown) to pivotally move the payload by 90 degrees between the retracted and the deployed positions.

[0065] In an aspect, the slotted hinge and the bell crank shaped arm are so configured that the pin travelling in the slot of the hinge blocks any movement of the hinge in the retracted and the deployed positions. Thus the hinge can be moved only when driven by the pin in the slot i.e. by link rod 210 and pulley 204 ensuring that is the mechanism is mechanically locked in retracted & projected positions and the camera is prevented from unintended movement due to inertia or gravitational forces or any other reasons in both these positions.

[0066] In an aspect, the retraction mechanism further comprises a spring (not shown) configured to bias the camera payload 102 against gravitational force to counterbalance the weight of the payload during projection. Thus the spring enables smooth descent of the payload.

[0067] In order to ensure compactness of retraction mechanism, the tilt rotation subsystem and corresponding servo can be placed on the top of the camera, instead of placing it along the frame/casing, thus saving space and simplifying the layout.

[0068] In an embodiment, to avoid damage caused to electronic components of the aircraft and the retractable payload assembly due to collection of foreign objects such as sand, dust, stones, etc. in the space that holds the stowed camera payload 102, through the opening 108 after the camera payload 102 is moved to the deployed position, a slider flap 108 can be provided at the bottom face of the fuselage as means to close the opening and prevent debris from entering into the compartment.

[0069] In an embodiment, the slider flap can be driven by a rack and pinion mechanism that can slide the flap to and fro when the camera payload 102 is moved from its retracted position to projected position and from projected position to retracted position. The slider mechanism can be driven by the retraction servo 202 that drives the retraction system through the pulley 204. A pulley belt can connect the pulley 204 to a pinion pulley to drive the pinion 206. The pulley 204, the pulley belt and the rack-pinion combination 206/208 (refer FIG. 2B) can be configured in a specific ratio with respect to each other in order to ensure precise and timely deployment of slider flap to close and open the camera payload compartment when the camera gets projected and retracted respectively.

[0070] In an exemplary configuration, the pulley 204 can be connected to the pinion pulley of the rack and pinion combination 206/208 through the pulley belt in 1 :3.4 ratio, while the pinion pulley 206 can be connected to the pinion gear in a 1: 1.46 ratio. In the exemplary configuration, the rack can get displaced by 187 mm when the pulley 204 gets rotated by 90°.

[0071] In an embodiment, the retractable camera payload can be a two-axis camera designed to fit inside the aircraft fuselage cross section. In particular, embodiments of the present disclosure relate to a retractable camera system that can be housed at zero position within the UAV fuselage cross-section so that it can withstand high-impact situations of landing and take-off. During flight, the camera can be deployed vertically downward from its retracted/stowed position, perpendicular to the fuselage. In an aspect, the two-axis camera payload with a belly mount arrangement designed to be as compact as possible to fit inside the aircraft fuselage cross section wherein the cross-section may be a 4-cell standard battery size to be used for aircraft operations. The payload can comprise three servos to actuate each operation of the camera payload - retraction, pan and tilt. In another aspect, the pan & tilt mechanisms can function only when the payload is in projected position.

[0072] In an aspect, the pan mechanism can provide pan rotation of the camera where the camera can be rotated by 270° along a vertical pan axis. The pan mechanism can be a servo driven step-up gear mechanism and can be configured to provide 270° pan rotation to the camera as the servo gear moves by 90°. The camera can pan 0° to +90° towards right and 0° to 180° towards left wherein 0°represents front looking position (in the direction of flight) of the camera.

[0073] In an exemplary embodiment, 270° pan rotation of camera system along the vertical pan axis is provided through an indirect driven step-up gear mechanism that provides 270° pan rotation for 90° rotation of the pan servo gear. A dual gear mechanism comprising the pan servo gear and pan action gears are designed to be of a specific size, with a ratio of 1 : 1.16 with respect to each other.

[0074] In an embodiment, the tilt mechanism can be configured to tilt the camera by 180° along a horizontal axis by means of atilt servo driven gear mechanism. The camera tilt motion can be 0° to 180° wherein 0° represents front looking position and 180° is rear looking position (in the direction of flight) of the camera(with pan angle being 0°)

[0075] In an exemplary embodiment, tilt mechanism can be an indirect driven gear mechanism. A dual gear mechanism comprising tilt servo and tilt gears which are of equal size, rotate the payload in tilt axis, from 0° to 180°.

[0076] FIG. 3A to 3C illustrates exemplary views of the camera payload in projected position installed at the fuselage belly, tilted and panned at different angles in accordance with an embodiment of the present disclosure. As shown in FIG. 3 A, the camera payload 102is projected vertically down from fuselage of the aircraft and panned at 90°to right (i.e. +90°) along the vertical pan axis and tilted at 45° along the horizontal tilt axis.

[0077] FIG. 3B shows the camera payload 102 panned at 90°to left (i.e. -90°) along the vertical pan axis without any tilt in rightward looking position whereas FIG. 3C shows the camera payload 102 panned at 180° to right (i.e. +180°) along the vertical pan axis without any tilt. In this position the camera payload 102 is in rearward looking position.

[0078] FIG. 4A and FIG. 4B illustrate exemplary mechanical linkages that enable the camera payload 102 to be in moved between the retracted and projected positions in accordance with embodiments of the present disclosure. FIG. 4A shows retracted position 400 of the payload 102 and FIG. 4B shows projected position 450 of the payload 102. The retraction and projection mechanism can be enabled with locking feature with help of mechanical linkages as show in FIG. 4A and FIG. 4B. The mechanism can include a servo driven pulley 204, a link rod 210, a bell crank shaped arm 402 comprising of two pins such as first pin (not shown here) and second pin 408 and a slotted hinged 404 that can pivot about pivot point 406. The servo driven pulley 204 can move the link rod 210 to further drives the bell crank shaped arm 402 to make it pivot about its pivot point. Pivotal movement of the arm 402 makes the second pin 408 to travel in the slot of the slotted hinge 406 so as to pivotally move the slotted hinge 406 thereby the payload 102 from retracted position to project the payload in the downward direction position. Likewise reverse rotation of the pulley 204 can make the payload 102 move from the deployed position to the retracted position.

[0079] In an aspect, the disclosed linkages mechanism also locks the payload in the two positions to prevent any unwanted movement of the pay load due to inertia and gravitational forces. As can be seen from FIG. 4A and FIG. 4B, The second pin 408 is configured in the slot of the slotted hinge 406 such that the arm 402 is perpendicular to the direction of the slot therefore the second pin 408 prevents any unintended movement of the slotted hinge 406. The hinge 406 can be moved only by movement of the arm 402 which can make the second pin to travel in the slot to make the hinge 406 move.

[0080] FIG. 5 illustrates front view of payload in projected position. As shown in FIG. 5, the tilt servo enable along with the gear mechanism 502 can provide tilt motion to the camera and the pan servo can enable pan rotation. In an exemplary embodiment, 270° pan rotation of camera system along the vertical pan axis is provided through an indirect driven step-up gear mechanism that provides 270° pan rotation for 90° rotation of the pan servo gear. A dual gear mechanism comprising the pan servo gear and pan action gears are designed to be of a specific size, with a ratio of 1: 1.16 with respect to each other. In an embodiment, the tilt mechanism can be configured to tilt the camera by 180° along a horizontal axis by means of atilt servo driven gear mechanism. The camera tilt motion can be 0° to 180° wherein 0° represents front looking position and 180° is rear looking position (in the direction of flight) of the camera (with pan angle being 0°) In an exemplary embodiment, tilt mechanism can be an indirect driven gear mechanism. A dual gear mechanism comprising tilt servo and tilt gears which are of equal size, rotate the payload in tilt axis, from 0° to 180°.

[0081] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION

[0082] The present disclosure provides a retraction mechanism for a payload for various platforms such as UAVs, other Aerial and ground vehicles, fixed hidden cameras, etc.

[0083] The present disclosure provides a retraction mechanism based on linkages that occupy less space.

[0084] The present disclosure provides a payload retraction system that mechanically gets locked in retracted and deployed positions to prevent unintended movement of the payloadduring landing or due to gravitational pull.

[0085] The present disclosure provides a payload retraction system that allows movement only when corresponding servo is operated.

[0086] The present disclosure provides a retractable payload comprising a two-axis camera designed to fit inside the aircraft fuselage cross section.

[0087] The present disclosure provides a system for the camera to be oriented vertically downward during its deployed position, perpendicular to the fuselage, during flight.

[0088] The present disclosure provides a retractable camera system to be housed within the UAV fuselage cross-section so that it withstands high-impact situations of landing and take-off.

Claims

We Claim:

1. A retraction mechanism for moving a payload between a retracted position and a deployed position, the retraction mechanism comprising:

a retraction servo drive, and

at least one set of linkages configured between the payload and the servo drive to move the payload between the retracted position and the deployed position when driven by the retraction servo drive;

wherein, in the retracted and the deployed positions of the payload, the set of linkages are moved only when driven by the retraction servo drive to ensure that the payload is mechanically locked in these positions.

2. The retraction mechanism of claim 1, wherein the at least one set of linkages comprise:

a pulley driven by the retraction servo drive;

a link rod in operational engagement with the pulley and configured to move when the pulley is driven by the retraction servo drive;

a bell crank shaped arm configured to be driven by the link rod; and

a slotted hinge wherein the arm engages the slotted hinge through slot in the slotted hinge and moves the slotted hinge to pivotally move the payload between the retracted position and the deployed position;

wherein, in the retracted and a deployed positions of the payload, the slotted hinge is moved only when driven by the link and pulley mechanism to ensure that it is mechanically locked in these positions.

3. The retraction mechanism of claim 2, wherein the bell crank shaped arm comprises a first pin and a second pin, wherein the link rod engages with the bell crank shaped arm through the first pin; and wherein the arm engages with the slot of the slotted hinge through the second pin.

4. The retraction mechanism of claim 2, wherein the pivotal movement of the payload between a retracted and a deployed position is 90 degrees along a horizontal axis and the payload projects vertically down in the deployed position.

5. The retraction mechanism of claim 1, wherein the retraction mechanism further comprises a spring wherein the spring biases the payload against gravitational force to counterbalance the weight of the payload and enable a smooth descent of the payload.

6. The retraction mechanism of claim 1, wherein the retraction mechanism further comprises means to close opening of chamber where the payload is stowed in retracted position; and wherein the means to block opening of chamber is a sliding flap.

7. The retraction mechanism of claim 1, wherein the sliding flap is moved to and fro to open and close the chamber opening wherein the to and fro movement of the sliding flap is provided by a rack and pinion arrangement; and wherein the rack and pinion arrangement is driven by the retraction servo drive.

8. The retraction mechanism of claim 6, wherein the retraction mechanism is positioned on side of the chamber that stows the payload in the retracted position.

9. The retraction mechanism of claim 1, wherein the payload is a camera payload mounted in belly of a UAV.

10. The retraction mechanism of claim 9, wherein the camera payload, in its deployed position, pans along a vertical pan axis by 180 degrees to right and by 90 degrees to left from its forward looking position.

11. The retraction mechanism of claim 9, wherein the camera payload, in its deployed position, tilts along a horizontal axis by 180 degrees.

12. The retraction mechanism of claim 11, wherein the pan and tilt movement of the camera is provided by a pan servo drive and a tilt servo drive respectively and wherein the tilt servo drive is placed on top of the camera payload to reduce width of the UAV.