Patent Application
20140012433
A typical airship such as a blimp has a rigid outer envelope filled with a lifting gas such as helium. An airbag or ballonet disposed inside the envelope is used to provide vertical control of the airship and to provide ballast when the airship is aloft. In particular, air is evacuated from the ballonet to outside the airship to cause the airship to ascend and air is pumped into the ballonet to cause the airship to descend. Such an airship may include more than one ballonet to provide ballast and to control the nose-to-tail orientation of the airship.
Due to their rigid outer structures, typical airships may not be maneuverable in weather conditions involving high winds and/or turbulent air. Moreover, high-speed crosswinds may damage the rigid airship. As such, these airships are generally operated on calm days or when high-speed winds are not expected.
Aerostats also have an outer envelope filled with a lifting gas. However, unlike blimps, aerostats are secured to an object/body on the ground by a tether. One end of the tether is attached to the aerostat and another end of the tether is attached to the object that is securely stationed on the ground. The tether holds the aerostat in place over a particular area. As known to one of ordinary skill in the art, an aerostat is not equipped with a propulsion device and a flight controller and, therefore cannot self-navigate to a destination when disconnected from the tether.
Disclosed herein are a self-powered releasable aerostat, method and system for releasing and controlling the aerostat.
According to one aspect, a computer-implemented method for releasing and controlling an airship is provided. The method includes receiving instruction signals to release the airship for an autonomous flight, wherein the airship includes a plurality of body segments and a plurality of coupling elements for coupling adjacent body segments along a length of the airship, wherein the airship is detachably coupled to a ground unit through a tether unit, and wherein the airship includes a propulsion unit, an auto pilot unit, and a controlling unit for controlling the propulsion unit, the tether unit, and the auto pilot unit. The method further includes determining environmental conditions affecting the airship, evaluating an internal pressure level of each of the plurality of body segments and a stiffness level of each of the couplings elements, and determining whether the evaluated internal pressure levels and stiffness levels are substantially suitable to the determined environmental conditions. Based on a determination that the evaluated internal pressure levels and stiffness levels are substantially suitable to the determined environmental conditions, the method further includes, determining whether the propulsion unit is in an operational state, and then based on the determination that the propulsion unit is in an operational state, triggering a disconnection of the tether unit and an activation of the auto pilot unit.
According to another aspect, an airship includes a plurality of body segments Tillable with lighter than air gases, a plurality of coupling elements, each of which is positioned to couple adjacent body segments along a length of the airship, a releasable tether unit for securing the airship to a ground unit while the airship is aloft, a propulsion unit for facilitating an autonomous flight of the airship, a controlling unit for triggering a release of the tether unit, for actuating the propulsion unit, and for controlling internal pressure levels of the body segments and stiffness levels of the coupling elements.
According to another aspect, a non-transitory computer-readable medium comprising instructions executing the method for releasing and controlling an airship.
These as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it should be understood that the disclosure provided in this summary section and elsewhere in this document is intended to discuss the embodiments by way of example only and not by way of limitation.
In the accompanying figures, like reference numerals refer to identical or functionally similar elements throughout the separate views.
Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements. Further, the apparatus, method and system components have been represented, where appropriate, by conventional symbols in the drawings.
In the following detailed description, reference is made to the accompanying figures, which form a part hereof. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, figures, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.
As known to one of ordinary skill in the art, an airship, such as an aerostat or a blimp, has an envelope of flexible sheet material that is filled with a lighter than air (LTA) gas, such as helium. The envelope has an aerodynamic configuration, such as a teardrop shape, or a round configuration. However, the overall shape of the airship is set and may not be modified expect very slightly during the filling or removal of the LTA gas. Moreover, as stated above, due to the rigid outer structure, the airship may not be maneuverable in weather conditions involving high winds and/or turbulent air.
Accordingly, in one exemplary embodiment, an aerostat is configured as a segmented airship. Now referring to
As shown in
Now referring to
As known to one of ordinary skills in the art, one technique for providing power to electrical devices/systems aboard aerostat 50 is to carry an electrical generator on board. This arrangement is configured to provide all the necessary power needs of aerostat 50 in a somewhat efficient manner. Unfortunately, electrical generation equipment is quite heavy and decreases a potential load equipment that may be carried by aerostat 50. Another drawback of employing an on-board power generator is the reduced “availability” of aerostat 50. In other words, the generator typically only has enough fuel to electric components of aerostat 50 for a few days. At the end of which, aerostat 50 must be retrieved, serviced, and then re-deployed. In order to increase the availability of aerostat 50, a ground-based power supply system located in ground unit 52 is configured to provide power to aerostat 50 through tether 54. As such, any problem with the ground-based power supply system can be easily dealt with on the ground instead of having to retrieve aerostat 50 anytime the onboard electrical generator has a malfunction. Moreover, ground-based power supply system is used to supply power to aerostat 50 so that power sources, such as power storage units, on board aerostat 50 may be conserved while aerostat 50 is connected to ground unit 52. Based upon the foregoing, there is a need for a lighter tether that allows for an increase in any desirable load carried by aerostat 50. Moreover, there is need for a tether which provides more power to aerostat 50, provides redundancy and improved power delivery, and is configured to minimize an electromagnetic interference emanating therefrom.
Now Referring to
Moreover, attachment points 58 and 60 may include attachment mechanisms that may be swiveling fixtures, such as ball joints. Alternatively, each of the attachment mechanisms may be a u-joint, gimbal, or other mechanism. Furthermore, aerostat 50 may utilize multiple attachment mechanisms for tether 54 having a plurality of coupling features. Further, each of the attachment mechanisms may include a decoupling mechanism, such as is a guillotine-type mechanism that severs tether 54 as needed. In addition to the solenoid-initiated quick release device, the decoupling mechanism may be realized as any of the following, without limitation: a pyrotechnic device, or a wide variety of other detachment mechanisms.
Referring back to
As shown in
In one embodiment, ground unit controller 208 is configured to receive via communication line 204 data regarding the attitude and/or or altitude of aerostat 50 or of the operating status of the various components or systems of aerostat 50. Ground unit controller 208 may also receive via communication line 204 data collected by payload 210 or information regarding the operating status of the components associated with payload 210.
As shown in
Referring back to
In one embodiment, aerostat 50 can operate in an unmanned manner under control of controller 126. Moreover, ground unit 52 may also be unmanned after aerostat 50 has been launched. In another embodiment, the operation of aerostat 52 can be directed from remote controller 212.
In accordance with an exemplary embodiment, when aerostat 50 is secured to the ground by tether 54, the motors of propulsion module 130 are idle. In response to instruction signals from ground unit controller 208 or remote controller 212, aerostat controller 126 actuates such motors, confirms that propulsion module 130 is operational, disconnects tether 54, and navigates aerostat 50 to a predetermined location. In another embodiment, ground unit controller 208 or remote controller 212 may send instruction signals to direct aerostat controller 126 to activate the motors of propulsion module 130 and release aerostat 50 at a predetermined or particular time, or after a specified period of time elapses. Such instruction signals may direct aerostat controller 126 to release aerostat 50 when the weather is sufficiently favorable for flight. Further, remote controller 212 may be configured to remotely control the operation of aerostat 50, including propulsion maneuvers, flight maneuvers, and landing maneuvers.
To release tether 54, aerostat controller 126 directs a tether controller (described below) to actuate a release mechanism that disengages tether 54 from the first attachment point 58. Alternatively, to release tether 54, aerostat controller 126 directs the tether controller to actuate a release mechanism that disengages tether 54 from the second attachment point 60, and to trigger a retrieving mechanism that brings up tether 54 towards aerostat 50 for storage during the autonomous flight. This alternate arrangement of tether 54 facilitates the attachment of aerostat 50 to another ground unit that may not be equipped with a tether.
In one embodiment, before aerostat 50 is released from tether 54, ground unit controller 208 or remote controller 212 may send an instruction signal to the autopilot of aerostat 50 that includes a destination to which aerostat 50 should fly after its release. Ground unit controller 208 or remote controller 212 may send another instruction signal to aerostat controller 126 to undertake a controlled descent of aerostat 50. Such instruction signal may direct aerostat controller 126 to undertake the controlled descent of aerostat 50 immediately, at a particular time, or after a specified period of time elapses. Such instruction signals may direct aerostat controller 126 to controllably descend aerostat 50 when the weather is sufficiently favorable for such operation. In response to such instruction signals, aerostat controller 126 may direct segment controllers 124 of each segment 102, 104, and 106 to operate segment fill-fan-and-valve assembly 120 to deflate such segments. Aerostat controller 126 may also direct controllers 124 to operate segment closer modules 116 to control the stiffness of couplings 113 associated therewith to facilitate control of the descent of aerostat 50.
As such, one would recognize that the controlled descent of aerostat 50 may occur while aerostat 50 is attached to tether 54 or after aerostat 50 is released from tether 54. For example, ground unit controller 208 or remote controller 212 may direct aerostat controller 126 to actuate the motor of propulsion module 130, disengage aerostat 50 from tether 54 or disconnect tether 54 from ground unit 52, use propulsion module 130 to navigate to a predetermined location transmitted to the autopilot of aerostat 50, and controllably descend aerostat 50 or release tether 54 upon reaching such location.
In order to improve on the aerostat autonomous flying, aerostat controller 126 may be coupled to following sensors are used: a Global Positioning System (GPS) receiver (not shown), a digital compass (not shown) that provides the airship heading (yaw), pitch and roll angles, two piezoelectric vibrating gyros (not shown) that provide the pitch and yaw rates. Besides, an altimeter and a speedometer, both based on silicon piezo-resistive pressure sensors, may be used for helpful environment information.
In one exemplary embodiment, aerostat controller 126 is configured to detect whether the tether 54 is severed, unexpectedly disconnected, or otherwise compromised. In another embodiment, aerostat controller 126 is configured to monitor the power supplied through power line 202 and to determine that the tether 54 has been compromised if such power is interrupted. In still another embodiment, ground controller 208 or remote controller 212 may transmit a particular signal, such as a heartbeat signal, at predetermined intervals and aerostat controller 126 may determine that tether 54 has been compromised if such heartbeat signal is not received when expected. Other characteristics of tether 54 that may be monitored by aerostat controller 126 to determine continuity of tether 54 will be apparent/obvious to one of ordinary skills in the art.
Upon determining that tether 54 has been compromised, aerostat controller 126 may undertake instructions previously transmitted thereto and/or stored in a memory thereof. In one embodiment, such instructions may direct aerostat controller 126 to cause aerostat 50 to navigate to a predetermined location, and optionally, descend upon reaching such location. In another embodiment, such previously transmitted and/or stored instructions may direct aerostat controller 126 to immediately begin a controlled descent of aerostat 50 once tether 54 is compromised.
Moreover, if tether 54 is compromised, the previously transmitted or stored instructions may cause aerostat controller 126 to direct segment controllers 124 to dump the lifting gas from one or more of the segments 102, 104, and 106 of aerostat 50 to facilitate a rapid descent of aerostat 50. Other actions that may be undertaken in response to a determination that tether 54 has been compromised will be apparent/obvious to one of ordinary skills in the art.
The actions described above that may be undertaken when aerostat controller 126 determines that tether 54 has been compromised may also be undertaken in other emergency situations. Further, such actions may be undertaken upon a command transmitted by ground control unit 208 and/or remote controller 212.
Referring to
Aerostat controller 126 is configured to control a propulsion module 408 to move the head segment 102 in a particular direction and control the attitude of head segment 102. Aerostat controller 126 also monitors and adjusts the inflation pressure, the heading, and the attitude of each of the segments 102, 104, and 106 to ensure that remaining segments 104 and 106 of aerostat 50 follow head segment 102 while minimizing the forces of the wind on the segments of aerostat 50. As such, on board propulsion module 408 and controller 126 enable aerostat 50 to handle changes in ambient wind, and hence can relocate and fly around.
Control system 400 further includes a power module 410 to provide electrical power to the components thereof. Power module 410 may provide power supplied via power line 202 in tether 54, if available, or from a power source onboard aerostat 50. The onboard power source may be any suitable source of electrical energy including a battery, solar cell, wind generator, or a combination thereof. Alternatively, the onboard power source may be a self-harvesting power unit that draws its electrical energy from mechanical energy generated by aerostat movements, such as on vibrations and oscillations.
Control system 400 further includes a communication module 411 coupled to the airship controller 126 that includes a transceiver to facilitate wired or wireless communications between aerostat controller 126 and ground unit controller 208 and/or the remote controller 212.
In one embodiment, aerostat controller 126 is coupled to a tether controller 412, which is configured to monitor the continuity of tether 54 and to provide signals to aerostat controller 126 that indicate whether tether 54 has been compromised. Further, tether controller 412 is configured to control the solenoid driven release to disengage aerostat 50 from tether 54.
In the above described embodiments, tether 54 is the only element attaching/securing aerostat 50 to ground unit 52. In another embodiment, multiple tethers may be used. Now referring to
Referring to
Referring to
As discussed above, if controller 126 receives an instruction from ground unit controller 208 or remote controller 212 to disengage tether 54 from aerostat 600 or from ground unit 52, controller 126 is configured to trigger an activation of propulsion unit 130, confirms that propulsion unit 130 is operational, and disengages tether 54 from the aerostat 600 or from ground unit 52. Thereafter, controller 126 navigates aerostat 600 in accordance with instruction signals received from ground unit controller 208 and/or remote controller 212. In one embodiment, aerostat 600 includes tail fins 604 to facilitate control and stability during flight thereof. In another embodiment, controller 126 is configured to operate fins 604.
Now referring to
Now referring to
Processing unit 802 can be implemented on a single-chip, multiple chips or multiple electrical components. For example, various architectures can be used including dedicated or embedded processor or microprocessor (μP), single purpose processor, controller or a microcontroller (μC), digital signal processor (DSP), or any combination thereof. In most cases, processing unit 802 together with an operating system operates to execute computer code and produce and use data. Memory unit 804 may be of any type of memory now known or later developed including but not limited to volatile memory (such as RAM), non-volatile memory (such as ROM, flash memory, etc.) or any combination thereof, which may store software that can be accessed and executed by processing unit 802, for example.
In some embodiments, the disclosed method may be implemented as computer program instructions encoded on a computer-readable storage media in a machine-readable format.
In some examples, signal bearing medium 901 may encompass a non-transitory computer-readable medium 903, such as, but not limited to, a hard disk drive, memory, etc. In some implementations, signal bearing medium 901 may encompass a computer recordable medium 904, such as, but not limited to, memory, read/write (R/W) CDs, R/W DVDs, etc. In some implementations, signal bearing medium 901 may encompass a communications medium 905, such as, but not limited to, a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, etc.).
It will be appreciated that some embodiments may be comprised of one or more generic or specialized processors such as microprocessors, digital signal processors, customized processors and field programmable gate arrays (“FPGAs”) and unique stored program instructions (including both software and firmware) that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the method and/or apparatus described herein. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used.
In one embodiment, the method 700 may also be implemented in hardware using any of the following technologies, or a combination thereof, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.
In the foregoing specification, specific embodiments have been described. However, various modifications and changes can be made without departing from the scope of the claims herein. For example, method steps are not necessarily performed in the order described or depicted, unless such order is specifically indicated. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the claims.
The present application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/644,183, filed May 8, 2012, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61644183 | May 2012 | US |
