WO2011005851A2

WO2011005851A2 - Aerostat assembly

Info

Publication number: WO2011005851A2
Application number: PCT/US2010/041197
Authority: WO
Inventors: Harry M. Capper
Original assignee: Capper Harry M
Priority date: 2009-07-08
Filing date: 2010-07-07
Publication date: 2011-01-13
Also published as: WO2011005851A3

Abstract

The invention is an aerostat assembly, specifically an aerostats assembly including a camera for aerial photography. The aerostat assembly includes a boom assembly joined to a buoyant aerostat balloon. The boom assembly includes a pivot assembly joined to the tether line and booms. Thrusters at the ends of the booms allow an operator to maneuver the assembly to desired positions as well as rotate the booms about the pivot assembly.

Description

Aerostat Assembly

Field of the Invention

The invention relates to aerostat assemblies, in particular, aerostats assemblies having a camera for aerial photography.

Background of the Invention

It is known to use aerostat aircraft or model helicopter aircraft having a mounted camera to capture aerial photographic and video images . Aerostats are aircraft that remain aloft primarily by lift provided by a buoyant balloon and/or by aerodynamic lift provided by the contoured shape of the balloon. Conventional aerostats are moored to the ground by a tether line to prevent escape from the operator. Helicopters remain aloft through lift provided by an engine driven rotor.

Using conventional aerostats for aerial photography is difficult. Aerostats allow little operator control. Positioning the camera to maintain a picture frame is difficult as aerostat position is affected by wind. The ability to maneuver and rotate an aerostat is limited. Shifting winds require repositioning of the aerostat and tether line to maintain a picture frame. Much operator effort is required to keep the tether line and other aerostat components from blocking or falling into the picture frame.

Additionally, balloons used with conventional aerostats must be very large to provide sufficient lift to raise the aerostat to a desired elevation. Trucks or like large vehicles are needed to transport the balloon and tanks containing appropriate amounts of the expensive lighter-than-air gasses required to fill the balloon.

While helicopters offer an improved degree of positional control over conventional aerostats, constant use of rotors transmits vibrations to attached cameras, resulting in impaired image quality. Constant rotor operation to maintain lift consumes large amounts of energy and limits fight times, limiting the amount of time a camera can maintain a desired aerial picture frame. If rotors or other mechanical components fail, helicopter control becomes impossible. The helicopter will crash to the ground, damaging the helicopter and attached camera equipment and risking injury to bystanders .

Thus, there is a need for an improved aerostat assembly for taking aerial pictures . The aerostat assembly should allow the operator to maintain precise control over camera position regardless of wind shifts or aircraft position, should be easy to transport with reduced use of expensive lighter-than-air gasses, should transmit minimal vibrations to camera equipment, allow prolonged flight times and reduce injury risk to equipment and by-standers in case of control or power failure .

Summary of the Invention

The disclosed invention is an improved aerostat assembly for taking aerial pictures. The assembly allows an operator to have precise control over aerostat camera position regardless of wind shifts, is easy to transport, uses smaller quantities of expensive lighter-than-air gasses than conventional aerostats, transmits minimal vibrations to camera equipment, allows greatly prolonged flight times over helicopter-type aircraft and reduces injury risk to equipment and by-standers in case of control or power failure.

The assembly includes a boom assembly joined to a buoyant aerostat balloon by a tether line. The boom assembly includes a pivot assembly joined to the tether line and booms extending away from the pivot assembly. A camera is mounted to a boom to capture aerial pictures. Fan thrusters located at the ends of the booms allow an operator to maneuver the assembly to a desired position, position the booms about the pivot assembly independently of the assembly's position and rotate the assembly about its yaw, pitch or roll axes as desired. The ability to freely position the assembly allows an operator to maintain a desired picture frame in shifting wind conditions .

The assembly also allows an operator to apply additional lift force to the assembly using the thrusters. This permits use of smaller balloons containing smaller quantities of expensive lighter-than- air gasses than conventional aerostats. These balloons can be transported using a station wagon or van rather than a truck or other larger vehicle. Smaller balloons are easier to transport to a launch site and require less time and effort to prepare for launch. The use of a balloon in the assembly as a lift source removes the need to use large lift rotors found in model helicopters. This reduces vibrations that disturb camera use and allows for greatly prolonged flight times over helicopter-type aircraft. Additionally, in case of partial or total thruster failure, the balloon prevents the assembly from crashing to the ground, greatly reducing the risk of equipment damage or by-standard injury.

The aerostat assembly may be tethered to the ground or used in an untethered embodiment that allows the operator greater freedom in maneuvering the assembly.

The assembly may be adapted to indoor use in arenas, stadiums and other large structures .

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawing sheets illustrating the invention.

Description of the Drawings

Figure 1 is a perspective view of a tethered aerostat assembly;

Figure 2 is a perspective view of a boom assembly;

Figure 3 is a top view of a boom assembly;

Figure 4 is perspective view of a center support frame; Figure 5 is a perspective view of a center support;

Figures 6 and 7 are perspective views of a center support pivot assembly;

Figure 8 is a partial sectional view of the center support pivot assembly of Figure 7; Figure 9 is a sectional view of the center support pivot assembly of Figure 6;

Figures 10 and 11 are perspective views of booms;

Figure 12 is a perspective view of a thruster assembly;

Figures 13 and 14 are other perspective views of tethered aerostat assemblies;

Figure 15 is a perspective view of an untethered aerostat assembly; and

Figure 16 is a representational view of the aerostat assembly superimposed over a coordinate system.

Detailed Description of the Invention

Figure 1 is a perspective view of an aerostat assembly 10 of the present invention tethered to ground 12.

Assembly 10 is made up of an aerostat balloon 14 jointed to a boom assembly 16 by a tether line 18. Boom assembly 16 hangs freely under balloon 14 and is supported by tether line 18.

The tether line 18 joining boom assembly 16 to aerostat balloon 14 may be a length of flexible conventional cord or line used to tether aerostat assemblies or may be a short linkage made of metal or other study, inflexible material. If desired, the tether line 18 joining the boom assembly 16 to aerostat balloon 14 may include multiple lines as shown in Figure 14.

Aerostat balloon 14 may be any conventionally known balloon used for moored balloons, blimps or other free flying airships. Balloon 14 is filled with a buoyant, lighter-than-air gas 20 that provides lift to assembly 10. If desired, balloon 14 may be a kite-type aerostat that provides aerodynamic lift though an oblate body shape, fins or other appropriately shaped surfaces.

Boom assembly 16 has a center support 22 and opposed booms 24 and 26 extending to either side of support 22.

Center support 22 is made up of frame 28 and pivot assembly 30. See Figures 4 through 6.

Frame 28 has top and bottom plates 32 and 34. Top plate 32 has an aperture 36 and bottom plate 34 has an aperture 38. Frame plates 32 and 34 are joined together by support walls 40 and 42 located at either end of frame 28. Each support wall 40 may include a hole 44 to reduce frame weight. The plates and walls define boom arm mounting apertures 46 located at either end of frame 28.

Pivot assembly 30 is attached to frame 28. Pivot assembly 30 may be a gimbal assembly 48. Gimbal assembly 48 includes a mounting plate 50, a rolling element assembly 52 and a pivot ball 54.

Mounting plate 50 includes a number of mounting holes 56 and a mounting plate aperture 58.

Rolling element assembly 52 is located within mounting plate aperture 58 and includes an assembly ring 60 rotatably joined to plate 50. Ball bearings 62 seated in plate groove 64 and ring groove 66 allow free rotation of assembly ring 60 relative to mounting plate 50.

Assembly ring 58 has a ring aperture 68. Pivot ball 54 is seated within ring aperture 68 and includes a ball aperture 70. Pivot ball 54 rotates and pivots freely relative to assembly ring 60.

Tether line mounting tube 72 is connected to ball 54, extends through ball aperture 70 and includes an engagement end or plate 74 at the lower end of the tube. Plate 74 includes a central aperture 76.

Pivot assembly 30 is joined to frame 28 to form center support 22. Pivot assembly 30 is secured to frame 28 by extending fasteners through mounting holes 56 and into like mounting holes in top plate 32 to secure mounting plate 50 to frame top plate 32.

Tether line 18 includes a stop or knot 78 that engages mounting tube plate 74 at aperture 76 to secure center support 22 and boom assembly 16 to tether line 18. See Figure 9.

Pivot assembly 30 may be the gimbal assembly 48 described above, a pivot ball alone, or any pivot assembly known in the art that allows free rotation and pivoting of boom assembly 16 about tether line 18. Pivot assembly 30 may include a rotational swivel coupling.

Gimbal assembly 48 may be a swash plate assembly from a model helicopter. The swash plate assembly may be Thunder Tiger Raptor brand swash plate assembly, part number PVOOlO.

Pivot assembly 30 allows boom assembly 16 to rotate freely about center support 22 and allows the operator to rotate the assembly about its yaw, pitch or roll axes as explained in detail below.

If desired, pivot assembly 30 may include a gimbal lock. When activated, the gimbal lock prevents the assembly from rotating about a yaw or roll rotational axis as selected by the operator. If desired, the gimbal lock may prevent assembly rotation about more than one rotational axis. This allows the operator improved control of the assembly in certain wind conditions.

The boom assembly rests in mechanical equilibrium. In the absence of thrust or wind forces acting on the boom assembly, the boom assembly remains in a horizontal position regardless of the angle of tether line 18, tether line mounting tube 72 and pivot ball 54 within the angular tolerance of the assembly. The angular tolerance of pivot assembly 30 shown in shown in Figures 6 and 7 is about 45 degrees, but may vary depending on the pivot assembly in center support 22.

Booms 24 and 26 each have an elongate arm 80 extending from an arm inner end 82 to an arm outer end 84.

Each arm 80 is jointed to center support 22 by placing an arm inner end 82 into a mounting aperture 46. Adhesive is used to secure each arm inner end in a mounting aperture 46.

A fan thruster assembly 86 is jointed to arm outer end 84. Thruster assembly 86 includes thruster assembly base 88 joined to a rotational assembly 90 and a fan thruster 92 joined to the rotational assembly.

Rotational assembly 90 allows an operator to rotate fan thruster 92 relative to the boom arm. Rotational assembly 90 may include a servomotor 94.

Fan thruster 92 includes a motor attached to a number of fan blades 96 in a guard collar 97 surrounding the fan blades. Fan thruster 92 is activated so that the motor turns the fan blades at a desired speed to provide a desired amount thrust to maintain or change the position of the aerostat assembly. Rotational assembly 90 is activated to allow the operator to control thrust direction by rotating fan thruster 92 relative to the boom arm .

Thruster 92 may include an electrically powered motor, a liquid fuel powered motor or another motor known in the art to rotate thruster fan blades .

Rotational assembly 90 may include one servomotor 94 as shown in Figures 2 and 3.

In alternate embodiments, rotational assembly 90 may include more than one servomotor 94. See Figures 10, 11 and 12. Rotational assembly 90 includes a first servomotor 94' joined to base 88 and one end of an L- shaped bracket 98 and a second servomotor 94'' joined to the other end of bracket 98 and thruster 92.

A multiple servomotor rotational assembly allows an operator greater control over thrust direction than a single rotational assembly. Boom 24 includes a support 100 having a single T- shaped support arm 102. Support 100 includes a control module 104 mounted to arm 102. Module 104 receives thrust and positioning signals from a remote control device and relays the signals to thruster assemblies 86 through wires mounted to the boom or by wireless means . Module 104 includes an antenna 106 for receiving radio signals from the control device actuated by the on-ground operator of the assembly 10.

Support 100 also includes energy source 108. Source 108 stores electrical power or fuel for the thruster assemblies. Electrical power or fuel is distributed to the thrusters by wires or fuel lines leading from tank 108 to each thruster assembly (not shown) . If desired, tethered embodiments of the aerostat assembly may include a power or fuel line that extends from the ground and along the tether line to the boom assembly to provide power or fuel to the thruster assemblies.

If desired, center support 22 may also include one or more tilt sensors 110. Tilt sensor 110 may be a gyroscopic device adapted to measure the assembly's angular velocity around its yaw or roll axes. Sensor 110 automatically sends thrust and positioning signals to control module 104 to maintain a given assembly position about its yaw or roll axes and allows the operator to override these signals when desired to change assembly position.

Boom 26 includes a camera support 112 having a pair of support arms 114 and 116 and a support base 118 pivotally attached to arms 114 and 116 at pivot joints 120 and 122. A camera 124 is mounted on support base 118. A rotational assembly 126 located at pivot joint 120 allows an operator to adjust the position of support base 118 relative to support arms 114 and 116. This allows an operator to adjust camera tilt position. Rotational assembly 126 may include a servomotor.

If desired, camera support 112 may include a pitch sensor 127. Pitch sensor 127 may be a gyroscopic device adapted to measure the assembly's motion about its pitch axis. Sensor 127 automatically sends signals to actuate rotational assembly 126 to compensate for undesired motion about the pitch axis to maintain a desired camera tilt position and picture frame.

Rotational assembly 126 is activated by module 104 to adjust the position of support base 118 relative to arms 114 and 116. This allows an operator additional control of a camera picture frame.

Camera 124 may be a conventional analog or digital camera. Camera 124 is actuated by module 104 to activate the camera's shutter trigger and control other camera functions such as zoom, aperture and so forth. Digital camera 124 may include a memory storage device for storing large digital files of high-quality still or video images. Camera 124 may be capable of capturing infrared or ultraviolet radiation.

Camera 124 may be a digital camera capable of transmitting video and audio information received by the camera and relayed through module 104 to an operator. The video and audio information assists the operator in controlling the aerostat assembly. Camera 124 may contain an integrated power supply or may obtain power from energy source 108.

As stated above, pivot assembly 30 allows free rotation and pivoting of boom assembly 16 about tether line 18. Boom assembly 16 is constructed so that the weight of booms 24 and 26 are balanced about center support 22 so that boom assembly is in mechanical equilibrium and boom assembly remains generally parallel to the ground. Thrust forces or winds change the rotational position of the boom assembly about its pitch axis. The boom assembly returns to a position generally parallel to the ground when the thrust forces or winds cease .

An alternate embodiment of the invention is contemplated wherein the boom assembly includes only a single thruster assembly. This embodiment allows an operator to control the rotational position of the boom assembly while reducing boom assembly weight.

Alternate embodiments of the invention are contemplated wherein boom assembly 16 includes more than two boom arms balanced about center support 22 so that boom assembly is in mechanical equilibrium.

An aerostat assembly of the present invention may be operated in either a tethered embodiment having a tether line extending to a ground anchor or in an untethered embodiment that allows free-flight of the assembly. The tethered embodiment of aerostat assembly 10 is shown in Figures 1, 13 and 14. Tether line 18 extends from balloon 14 and through tether line mounting tube 68 at center support 22 to an anchor point 128 on the ground 12.

Figures 1 and 13 show a tethered aerostat assembly 10 at the end of a taut tether line 18. Tether line 18 is taut when the aerostat assembly has reached a maximum height. The tether line may also become taut when wind exerts force against the aerostat assembly to push the assembly in the direction of the wind until the tether line becomes taut as shown in Figure 13.

Figure 14 shows a tethered aerostat assembly 10 at the end of a slack tether line 18. Tether line 18 is slack when the aerostat assembly has not reached a maximum height as allowed by the length of the tether line or wind has not pushed the aerostat assembly to the limit of tether line length. The slack tether line allows some assembly maneuverability within the limits of the tether line.

The tethered embodiments of aerostat assembly 10 are conventionally used for outdoor applications. As stated above, the tethered embodiment of aerostat assembly 10 may include a power or fuel line that extends from the ground and along the tether line to the boom assembly to provide power or fuel to the thruster assemblies.

If desired, the tethered embodiment of aerostat assembly 10 may also include a data cable. The data cable extends from the ground and along the tether line to the boom assembly and transmits operator instructions to the thruster assemblies.

Figure 15 illustrates an untethered embodiment aerostat assembly 130. Aerostat assembly 130 tether line 18 does not extend to ground 12.

Untethered aerostat assembly 130 allows free-flight of the assembly without restriction from a ground- anchored tether line.

Untethered aerostat assembly 130 may be used for outdoor or indoor applications. When used for indoor applications, the balloon 14 is filled with a quantity of lighter-than-air gas sufficient to provide an upward lift force greater than the weight of the aerostat assembly. This allows the assembly to rest against the ceiling of the indoor space when not in use. If desired, the appearance of the aerostat assembly may be further masked by coloring the aerostat assembly an identical color as the ceiling.

Aerostat assembly 130 may include a spool or winch

132. Spool 132 may be electrically powered and is actuated by signals from control module 104. Spool 132 allows an operator to adjust the length of tether line 18 between the balloon and the boom assembly. This allows the operator to change the vertical position the boom assembly without activating the thruster assemblies and permits additional operator control over the camera position and camera's picture frame. Figure 16 is a representational view of aerostat assembly 10 superimposed over three-dimensional Cartesian system 134. Taut tether line 18 extends along Z-axis 136 from balloon 14 to boom assembly 16. Boom assembly 16 extends along X-axis 138 to center support 22. Center support 22 is located at system origin 140. The assembly faces forward in the direction of Y-axis 142.

Z-axis or yaw axis 136 is the vertical axis for the assembly. Assembly yaw motion about yaw axis 136 is illustrated by dashed arrow 144.

X-axis or pitch axis 138 is the lateral axis for the assembly. Pitch axis 138 extends along boom assembly 16. Assembly pitch motion about the pitch axis is illustrated by dashed arrow 146.

Y-axis or roll axis 142 is the longitudinal axis for the assembly. Assembly roll motion about the roll axis is illustrated by dashed arrow 148.

In the absence of wind or thrust forces acting on the assembly, the assembly rests in stable static equilibrium about it yaw, pitch and roll axes. When the assembly is in stable static equilibrium, pitch axis 138 and roll axis 142 are generally parallel to the ground.

The assembly operator controls rotational yaw motion 144 and roll motion 148 by manipulating thruster assemblies 86 as described below.

The assembly resists pitch motion 146, and will only undergo pitch motion 146 when affected by strong winds or rapid flight maneuvers. Any assembly pitch motion is detected by pitch sensor 127. Pitch sensor 127 will send signals to camera base rotational assembly 126 to compensate for pitch motion 146 to maintain a desired camera picture frame.

During aerostat assembly flight, an operator changes the position of the assembly by activating thruster assemblies 86.

For translational motion from one point in air space to another point in airspace or to hold the aerostat assembly in position against a wind, first both thrusters are pointed in an identical direction. The thrusters are then activated to produce identical amounts of thrust against the wind or in the direction of desired translation.

For embodiments in which the assembly balloon provides an upward lift force less than the weight of the aerostat assembly, the thrusters are used to provide an additional upward lift force for the aerostat assembly to raise the assembly to a desired altitude.

For use in indoor applications in which the assembly balloon provides an upward lift force greater than the weight of the aerostat assembly so that the assembly rests against a ceiling when not in use, the thrusters are used to provide a downward force to lower the assembly away from ceiling to accomplish maneuvers.

For rotational motion about its yaw or roll axes to turn the aerostat assembly, to compensate for wind or to move a boom into position to capture or maintain a picture frame, the thruster assemblies provide thrust proportionally, individually or together to achieve a desired rotational motion. The pivot assembly in center support 22 allows the boom assembly 16 to rotate freely about center support 22, permitting rotational motion about the yaw or roll axis.

Rotational motion 148 about roll axis 142 may be accomplished by increasing the amount of vertical thrust provided by one thruster assembly and reducing the amount of vertical thrust provided by the other. Vertical thrust is provided parallel to Z-axis 136.

Rotational motion 144 about yaw axis 136 is accomplished by providing yaw thrust in the X-Y plane. Yaw thrust is parallel to the roll axis 142 and is illustrated by arrow 150.

When the thruster assemblies are positioned to generate thrust within the X-Y plane, yaw thrust 150 is generated by one thruster assembly alone or by providing thrust from both thruster assemblies, each facing in opposite directions within the X-Y plane to provide thrust 150 and 150' to generate rotational motion 144.

When the thruster assemblies are positioned to generate both yaw thrust and a vertical thrust, the thruster assemblies face in opposite directions and provide thrust 150 and 150' to generate rotational motion 144.

Claims

1. An aerostat assembly comprising a balloon containing a quantity of buoyant gas, a boom assembly having generally elongate booms extending from a support member, a tether line extending from the balloon to the boom assembly support member; at least one boom having a thruster assembly located away from the support member, the support member having a pivot assembly engaging the tether line; each thruster assembly having a thruster; a controller, the controller actuating each thruster; the assembly having a yaw axis, a pitch axis and a roll axis; wherein said buoyant gas exerts an upward lift force on the aerostat assembly, the boom assembly being in mechanical equilibrium, the pivot assembly allows rotation of the boom assembly around the yaw axis, and a thruster exerts a turning force on the boom assembly parallel to the roll axis.

2. The aerostat assembly of claim 1 wherein each boom is approximately the same length, the support member located in the center of the boom assembly.

3. The aerostat assembly of claim 2 comprising two boom arms, the boom assembly is generally elongate and each boom arm comprises a thruster assembly.

4. The aerostat assembly of claim 3 wherein the thruster assembly comprises a rotational assembly.

5. The aerostat assembly of claim 4 wherein the pivot assembly allows rotation of the boom assembly about the roll axis and a thruster exerts a turning force on the boom assembly parallel to the yaw axis.

6. The aerostat assembly of claim 5 wherein a boom comprises a camera.

7. The aerostat assembly of claim 6 wherein the pivot assembly comprises a gimbal assembly.

8. The aerostat assembly of claim 7 wherein the rotational assembly comprises a servomotor.

9. The aerostat assembly of claim 8 comprising a spool assembly jointed to the tether line wherein the spool assembly adjusts the length of the tether line between the balloon and the boom assembly.

10. The aerostat assembly of claim 8 wherein the tether line extends from the boom assembly support member to the ground .

11. An aerostat assembly having a yaw axis, a pitch axis and a roll axis, the assembly comprising:

a balloon containing a quantity of buoyant gas;

a boom assembly having generally elongate booms extending from a support member and at least one boom having a thruster assembly located away from the support member; a tether line extending from the balloon to the boom assembly support member; the support member having a pivot assembly engaging the tether line;

each thruster assembly having a thruster and a rotational assembly;

a controller, the controller actuating each thruster assembly wherein said buoyant gas exerts an upward lift force on the aerostat assembly, the boom assembly being in mechanical equilibrium, the pivot assembly allows rotation of the boom assembly around the yaw axis, and a thruster exerts a turning force on the boom assembly parallel to the roll axis.

12. The aerostat assembly of claim 11 wherein each boom is approximately the same length, the support member located in the center of the boom assembly.

13. The aerostat assembly of claim 12 comprising two boom arms, the boom assembly is generally elongate and each boom arm comprises a thruster assembly.

14. The aerostat assembly of claim 13 wherein the thruster assembly comprises a rotational assembly.

15. The aerostat assembly of claim 14 wherein a boom comprises a camera.

16. The aerostat assembly of claim 15 wherein the pivot assembly comprises a gimbal assembly.

17. The aerostat assembly of claim 16 wherein the tether line extends from the boom assembly support member to the ground .