Patent Application
20100230533
A hybrid airship can combine the characteristics of different aviation technologies such as heavier-than-air (HTA) aircraft, lighter-than-air (LTA) vehicles, fixed wing aircraft, helicopter, hovercraft, and others, to perform desired functions. Hybrid airships are currently being developed that combine the advantages of an aerodynamic shape with the cargo capacity, simplicity, and low operating costs of airships. Uses for such vehicles include cargo transport, telecommunications platforms, surveillance, emergency response, advertising platforms, and tourism, among others.
LTA vehicles are typically slow and difficult to maneuver. Yet, it is desirable to develop a hybrid airship capable of take off and landing in a minimum amount of space. Traditional LTA vehicles with an air cushioned landing system (ACLS) have been proposed to reduce the take off and landing space requirement. However, many traditional ACLS systems have fixed configurations during take off and landing and also during the flight. This increases drag and reduces fuel efficiency. More recently, some LTA vehicles include an ACLS system that is operable in dual modes including a take off and landing mode that is suitable for landing and take off, and a flight mode that is suitable for operation during the flight of the vehicle. However, traditional tools and techniques that are used for enabling the dual mode ACLS system to transition between the flight mode and the take off and landing mode are often impractical, inefficient, and prone to frequent failures.
In some embodiments, an airship comprising a hull configured to be inflated with a first gas; a ballonet in the hull, the ballonet configured to be inflated with a second gas that is heavier than the first gas; a fan configured to draw the second gas into the ballonet; an inflatable landing system; a duct configured in the ballonet to allow access to components in the airship; and a valve coupled to the ballonet. The valve provides a pathway for air to flow between the ballonet and a plenum chamber, the plenum chamber is formed by the airship, a landing surface, and the inflatable landing system when the inflatable landing system is in contact with the landing surface.
Embodiments of the present invention can be better understood, and their numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference symbols in different drawings indicates similar or identical items.
An airship 100 equipped with ACLS 122, 124 offers considerable lifting capacity, operational flexibility, and cost effectiveness as well as the ability to operate from unimproved landing sites on both land and water. ACLS 122, 124 can be configured in accordance with a flight mode of the airship 100, for example, ACLS 122, 124 is typically fully inflated during landing, touchdown, and take-off, but deflated into a stowed position to reduce drag during up and away flight. An air cushion pad of the ACLS 122, 124 can be formed around an open center to create plenum chambers 130 when ACLS 122, 124 touches the ground. Valves 126, 128 can operate to form suction within the plenum chambers 130 to stabilize and retain airship 100 on the ground.
Ducts 110, 112 can be large enough to allow maintenance personnel to access various components such as propulsion systems 114, 116, fans 118, 120, and valves 126, 128. Ducts 110, 112 may also provide a route for electric cables, hydraulic lines, and other components internal to airship 100 with sufficient space to separate components such as electric cables and hydraulic or fuel lines from one another as required. Fans 118, 120 can supply air to ballonets 106, 108 and ACLS 122, 124. Valves 126, 128 can control airflow from fans 118, 120 to ACLS 122, 124. When ACLS 122, 124 are inflated, plenum chambers 130 are formed by the ACLS 122, 124 and landing surface 132. In some embodiments, fans 118, 120 are induction fans that draw air into ballonets 106, 108 through air vents 134 in the outer surface of airship 100.
Airship 100 can be equipped with an on-board source of lighter-than-air gas (not shown), such as compressed helium tanks or other suitable gas that are configured to supply hulls 102, 104. An onboard processing system, such as a computerized controller as further described in
Referring to
In takeoff, climb and/or cruise mode 502, the pressure of hull 102 is nominal (504), plenum pressure is unimportant (506), and the flow rate of fans 118, 120 is typically zero (508).
During initial ground contact mode (510), the altitude of the bottom of hulls 102, 104 is approximately equal to the height of ACLS 122, 124. The hull/ballonet pressures may be nominal (512), the pressure of plenum chambers 132 is nominal (514), and the flow rate of fans 118, 120 may be zero (516).
During ground settling mode 518, the altitude of the bottom of hulls 102, 104 is less than the height of ACLS 122, 124, and the downward velocity of the airship 100 is less than a predetermined value. The hull/ballonet pressure increases to greater than nominal (520), and the flow rate of fans 118, 120 is zero (522). Valves 126, 128 open so that air flows from plenum chambers 132 to ballonets 106, 108 as the weight of airship 100 compresses ACLS 122, 124 (524) as airship 100 comes to a stop (526).
During stop mode 530, the weight of airship 100 has settled and the altitude of the bottom of hulls 102, 104 is less than the fully-inflated height of the ACLS 122, 124. The pressure of ballonets 106, 108 is much greater than the nominal ballonet pressure as high pressure air from plenum chambers 132 flows into the ballonets 106, 108 (532). The over-inflation of ballonets 106, 108 causes the pressure of hulls 102, 104 to be greater than the nominal pressure (534). Fans 118, 120 are started to pressurize plenum chambers 132 (536).
Once airship 100 comes to a stop, airship 100 enters initial hover mode 538. During initial hover mode 538, the altitude of the bottom of hulls 102, 104 approximately equals the height of ACLS 122, 124 as the excess air pressure from hulls 102, 104 and ballonets 106, 108 is used to inflate plenum chambers 132. Fans 118, 120 can also operate to pressurize the plenum chambers 132 for hover (544). Valves 126, 128 between the plenum chambers 132 and the ballonets 106, 108 are open (546).
Once the pressure in hulls 102, 104, ballonets 106, 108, and plenum chambers 132 equalizes in initial hover mode 538, airship 100 enters hover mode 548. The altitude of the bottom of hulls 102, 104 approximately equals the height of ACLS 122, 124. The pressures in hulls 102, 104, ballonets 106, 108, and plenum chambers 132 are nominal (550, 552). Fans 118, 120 operate to maintain the plenum and ballonet pressure (554).
Referring again to
Referring to
Valve 601 can be opened to release air and closed to retain air in airship 100 manually or under automatic operation by controller 604.
A fan 602 provides an air pressure source with pressure sensors 606 that can adjust fan operation to accommodate gas volume expansion and contraction caused by atmospheric conditions (temperature and pressure) and leakage.
Controller 604 controls operation of pressure management system 600 to achieve a desired pressure according to the flight mode, as described with respect to
A number of switches 606 can be configured to send control commands to the controller 604 for various functions including a valve switch, high pressure alarm switch, low pressure alarm switch, high pressure switch, and low pressure switch, as shown for example in Table 1 below. Note that the numbers shown are for example only and may be varied depending on a particular vehicle's requirements/configuration.
If the vehicle is to be left unattended, low and high pressure alarm switches can be connected to an alarm system that provides alerts when high or low pressure conditions are detected. For example, the alarm system can be configured to make phone calls and play a message indicating the nature of the problem. The alarm system can be equipped with battery backup. Lights can also be connected to and operated by controller 604 to indicate status. For example, one light may indicate that the pressure maintenance system 600 has power. Another light may indicate that the fan has been commanded to run. Visual indicators can be located within view of a video camera or other visual monitoring system for remote monitoring.
Controller 604 can include mode switches (not shown) that set the mode of the controller 604 and status lights (not shown). The mode switches can include, for example, a valve switch, a fan switch, and a fan mode switch, as shown for example in Table 2 below:
In normal operation the fan switch and valve switch are typically left in automatic mode. Fan mode switch 624 can be set to low pressure, unless full vehicle pressure is required for maintenance or operational reasons. For example, fan mode switch may be set to HIGH as required to stretch hulls 102, 104 to full flight pressure to tighten lacing. A programmable relay can be used to delay fan shut-off to eliminate excessive cycling of fan 602 thereby preventing chatter and vibration.
Outlet duct 608 can be used to connect pressure maintenance system 600 to a ground pressurization port.
Power supply 610 provides suitable power to the components of pressure management system 600, such as thirty (30) amp, twenty-eight (28) volt direct current. Back up power supply 612 can provide an alternate power source using any suitable power supply, such as one or more batteries.
Fan override switch 614 bypasses the controller 604 to manually operate fan 602.
Circuit breaker switch 616 removes power and/or backup power from controller 604 in the event an overcurrent condition is detected.
Vehicle pressure line 618 can be coupled to a pressure manifold switch and pressure gage to control the pressure in hulls 102, 104 and/or ballonets 106, 108.
Note that when operating on battery power alone, fan 602 may not be able to produce the pressure required to maintain the airship 100 at the desired minimum pressure. Therefore, in the event of a power failure, the fan mode switch can be set to low pressure.
Referring to
Processor 702 can be any suitable computer-processing device that communicates with memory device 704 to access and execute logic instructions, such as logic instructions 706 to receive input from sensors and issue control commands to subsystems to transition to, establish and maintain desired flight modes of airship 100, such as the flight modes shown in
Logic instructions 706 can be executed by processor 702 and configured to operate airship 100 automatically as well as allow manual inputs from crewmembers. Logic instructions 706 can determine whether the modes requested by the crewmembers are permitted based on the current mode of airship 100, and issue alerts if desired operational modes cannot be achieved. Mode control and option selections can also be transmitted from crewmembers processor 702 to various subsystems to control operational modes of various subsystems. As shown, logic instructions 706 as executed by processor 702 send outputs to open and close valves 126, 128, control propulsion systems 114, 116 and fans 118, 120, and inflate and deflate hulls 102, 104, ballonets 106, 108, and ACLS 122, 124.
Logic instructions 706 executed by processor 702 can be stored in memory device 706, on computer readable medium, or accessed by processor 702 in the form of electronic signals. Processor 702 can be configured to interface with other processors, and to connect to an external network via a suitable communication link such as any one or combination of T1, ISDN, or cable line, a wireless connection through a cellular or satellite network, or a local data transport system such as Ethernet or token ring over a local area network.
Additionally, processor 702 can be embodied in any suitable computing device, and so include embedded computers, desktop computers, laptop computers, or other suitable computing devices. Processor 702 and corresponding logic instructions can be implemented using any suitable combination of hardware, software, and/or firmware, such as microprocessors, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuit (ASICs), or other suitable devices.
While the present disclosure describes various embodiments, these embodiments are to be understood as illustrative and do not limit the claim scope. Many variations, modifications, additions and improvements of the described embodiments are possible. For example, those having ordinary skill in the art will readily implement the processes necessary to provide the structures and methods disclosed herein. Variations and modifications of the embodiments disclosed herein can also be made while remaining within the scope of the following claims. The functionality and combinations of functionality of the individual modules can be any appropriate functionality. Additionally, limitations set forth in publications incorporated by reference herein are not intended to limit the scope of the claims. In the claims, unless otherwise indicated the article “a” is to refer to “one or more than one”.
