Abstract:
A modular component set is configurable to form a plurality of flight capable platforms. A plurality of end pieces each has contiguously connected curved outer portions each longitudinally expanding from a tip to terminate at a blunt attachment face. Body members have opposed ends to receive the end piece blunt attachment face, and a rectangular shaped mid-portion having opposed walls. A plurality of task specific panels are each releasably connectable to one of the opposed walls. At least one of the body members with the end pieces joined at the opposed ends, and at least one of the task specific panels connected to one of the opposed walls form a minimum component set for each of the flight capable platforms.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to flight capable mobile platforms and more specifically to a modularly designed vertical or near-vertical takeoff aircraft.  
       BACKGROUND OF THE INVENTION  
       [0002]     Current military doctrine relies on a limited number of high value assets to prosecute global events. The restriction to a one-man (or more) to one machine system severely impairs these finite forces&#39; ability to overcome overwhelming hostile force numbers and/or engage several theatres of operation simultaneously. Additionally, a severe lack of commonality between the vehicles used by individual services of the armed forces has increased the cost of those platforms while restricting their interoperability between services and NATO allies.  
         [0003]     The extremely complex and multiple part machinery used by the armed forces has several disadvantages. The initial cost to construct each unit is high. The follow-on cost to maintain each unit is also high due to the complexity of the systems in use. Additionally, highly complex machinery is more susceptible to damage and breakdown due to large numbers of moving parts, heavy reliance on software based computing systems for control and operation, and reliance on large numbers of highly trained maintenance personnel to maintain each vehicle.  
         [0004]     For military use aircraft, either vertical takeoff/landing, or very short takeoff and landing aircraft are particularly complex and expensive systems both to procure and maintain. The advantage of short or vertical takeoff aircraft is a greatly reduced length for takeoff and/or landing strips, which enable broader use of the aircraft in areas lacking these facilities. This advantage is partially negated when one takes into account the susceptibility to damage of the system in unimproved areas and the relatively significant maintenance infrastructure the complex system requires.  
         [0005]     It is therefore desirable to provide a modularly constructed aircraft to decrease the initial cost of each platform as well as to increase the number of and type of missions the aircraft can be modified to fly. It is also desirable to combine modular aircraft construction features with an aircraft having modularized and simplified vertical takeoff and landing propulsion devices.  
       SUMMARY OF THE INVENTION  
       [0006]     According to a preferred embodiment of the present invention, a modular component set is configurable to form a plurality of flight capable platforms. A plurality of end pieces each have a shaped tip portion and contiguously connected curved outer portions each longitudinally expanding from the tip to terminate at a blunt attachment face. A plurality of body members have opposed ends adapted to receive the end piece blunt attachment face, and a rectangular shaped mid portion having opposed walls. A plurality of task specific panels are each releasably connectable to one of the opposed walls. At least one of the body members with the end pieces joined at the opposed ends, and at least one of the task specific panels connected to one of the opposed walls form a minimum component set for each of the flight capable platforms.  
         [0007]     In one preferred embodiment, at least one vertical propulsion device is disposed in each of the body members. Two or more body members can then be joined either longitudinally or arranged in parallel sets. When parallel sets of the body members are formed, a payload bay is connectable between the two sets. A common nose/tail section is connectable to either end of each of the body members. Spacer members are used between parallel adjoining pairs of the nose/tail sections. One or more wing designs are mountable to the body members. Flight control surfaces are also mountable to either of the spacer members or the nose/tail sections.  
         [0008]     The task specific panels of the present invention are releasably attached to walls of the body members. Each of the task specific panels can mount a different task item, including missiles, torpedoes, sonobuoys, rockets, radar, and additional items such as fuel and power sources, etc. The task specific panels are interchangeable between individual flights of the aircraft of the present invention. Control equipment, energy sources such as batteries, and mechanical connecting equipment are examples of equipment which can be mounted within an envelope of the task specific panels. Except for required aircraft interface equipment, each task specific panel therefore acts as a stand-alone module. Different types of equipment can also be loaded on opposite panels of a particular aircraft. The task specific panels are structurally integrated into the body member walls such that a portion of the load imparted by the task devices as well as the panel itself are integrated into the body members, and body member loads are also similarly transferable to or through the task specific panels.  
         [0009]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0011]      FIG. 1  is an exploded perspective view of modular aircraft according to a preferred embodiment of the present invention;  
         [0012]      FIG. 2  is an assembled perspective view of the modular aircraft of  FIG. 1  further showing an exemplary horizontal propulsion device and a task specific set of items mounted to the aircraft panel;  
         [0013]      FIG. 3  is a perspective view of another embodiment of a modular aircraft of the present invention having a longitudinally joined pair of body sections and two separate pairs of wings;  
         [0014]      FIG. 4  is a perspective view of a task specific panel of the present invention showing an exemplary missile attached thereto;  
         [0015]      FIG. 5  is a perspective view of an exemplary task specific panel showing a torpedo attached thereto;  
         [0016]      FIG. 6  is a perspective view of an exemplary task specific panel showing a sonobuoy package attached thereto;  
         [0017]      FIG. 7  is a exemplary task specific panel showing a pair of rockets attached thereto;  
         [0018]      FIG. 8  is a perspective view of an exemplary task specific panel showing a radar module attached thereto and a modified exterior face providing additional volume for radar associated equipment;  
         [0019]      FIG. 9  is a perspective view of another embodiment of a modular aircraft of the present invention having multiple joined body sections, a payload bay, and spacer members attached thereto;  
         [0020]      FIG. 10  is a perspective view similar to  FIG. 9  showing an exemplary rudder and horizontal stabilizer pair attached to an aft spacer member;  
         [0021]      FIG. 11  is a sectioned elevation view taken at Section  11 - 11  of  FIG. 2 , showing an alternate embodiment of the present invention;  
         [0022]      FIG. 12  is a sectioned elevation view similar to  FIG. 11 , showing another embodiment of the present invention; and  
         [0023]      FIG. 13  is a flow diagram describing a method to modularly construct an aircraft of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0025]     According to a preferred embodiment of the present invention, shown in  FIG. 1 , a mobile platform  10  in accordance with one preferred embodiment of the present invention is shown. The mobile platform  10  forms a modular aircraft, and will be referred to for convenience by the term “modular aircraft”  10  herein. Modular aircraft  10  includes at least one body section  12  having a forward attachment face  14  and an aft attachment face  16 . The body sections  12  each include a starboard wall  18  and a port wall  20 , respectively. Each of the body sections  12  further includes at least one vertical propulsion device  22 .  FIG. 1  shows an exemplary set of six vertical propulsion devices  22 , which in this example include augmented pulsejet engines. The augmented pulsejet engines are disclosed in co-pending U.S. patent application Ser. No. 10/245,519 commonly assigned to the assignee of the present invention, and entitled “Pulsejet Ejector Thrust Augmentor”, filed Sep. 16, 2002, the disclosure of which is incorporated herein by reference.  
         [0026]     Each body section  12  further includes a cavity  24  formed in each of the starboard wall  18  and the port wall  20 . A plurality of fastener apertures  26  are shown around a perimeter of the cavity  24  (the port cavity is shown for clarity only). A task specific panel  28  is connectably fastened to each of the cavities  24  using each of a plurality of fasteners  30  which align through a plurality of apertures  32  in coalignment with each of the fastener apertures  26 . The task specific panels  28  will be described in further detail in reference to  FIGS. 4-8 .  
         [0027]     An end piece  34  is connectably joined to both the forward attachment face  14  and the aft attachment face  16  of the body section  12 , using fasteners (not shown) or alternate attachment devices including adhesives, rivets, welding, and clips. Each end piece  34  includes a tip  36  and a plurality of contiguous rounded sides  38 . Each of the rounded sides  38  ends at a blunt attachment face  40 . The blunt attachment face  40  is dimensionally controlled to the approximate geometry and perimeter of each of the forward attachment face  14  and the aft attachment face  16  of body section  12 . A starboard wing  42  and a port wing (not shown for clarity) are attached to the body section  12  at a location on either of the starboard wall  18  or the port wall  28  preferably above or optionally below the location of the task specific panels  28 . Pulsejets  43  embedded in winglets of wings  42  can be differentially controlled for roll control. At least one of the body sections  12 , at least two of the end pieces  34 , and at least one of the task specific panels  28  connected to one of the starboard or port walls  18  and  20 , respectfully, forms a minimum component set for the modular aircraft  10 .  
         [0028]     Referring next to  FIG. 2 , an assembled modular aircraft  44  using the basic parts identified in  FIG. 1  and additional components is shown. Modular aircraft  44  includes a single body section  12  having a pair of end pieces  34  forming a forward or nose section and an aft or tail section, respectively. A pair of members  46  are connected to the aft located end piece  34 . Each of the members  46  perform several functions, including acting as flight control surfaces for steering the modular aircraft  44  and as ground supporting members for the modular aircraft  44  when in a landed or stored position. The task specific panel  28  shown is modified to include a pair of rockets  48 . Forward propulsion for the modular aircraft  44  is provided by a propeller  50 . Engine components (not shown for clarity) connectable to the propeller  50  are disposed in the end piece  34  acting as the tail section of the modular aircraft  44 . Fuel for the modular aircraft  44  is provided in either or both of the end pieces  34 , as well as in excess volume located in body section  12  (e.g., area near wing attachment).  
         [0029]     Modular aircraft  44  is envisioned as an unmanned aircraft, having internal flight guidance and control equipment (not shown) for remote flight control of modular aircraft  44 . It should be obvious the size of modular aircraft  44  can be varied, depending on the size of the individual component parts and the desired mission of modular aircraft  44 .  
         [0030]     Referring next to  FIG. 3 , a modular aircraft  52  according to another embodiment of the present invention is shown. Modular aircraft  52  includes a forward body section  54  and an aft body section  56 , respectively, both similar to body section  12  described in reference to  FIG. 1 . Modular aircraft  52  is formed by joining forward attachment face  14  of aft body section  56  to aft attachment face  16  (shown in  FIG. 1 ) of forward body section  54 . By joining two body sections together in longitudinal alignment as shown, both a forward task specific panel  58  and an aft task specific panel  60  can be mounted to both sides of modular aircraft  52 . Forward and aft ends of modular aircraft  52  are formed by end pieces  34 , similar to those described in reference to  FIG. 1 . Modular aircraft  52  also includes two pairs of wings  42 .  
         [0031]     As best described in references to  FIGS. 4-8 , a plurality of task specific panels  28  are described. As shown in  FIG. 4 , an exemplary task specific panel  28  includes an exterior face  62  and an interior face  64 . Exterior face  62  is modified to provide support for a missile  66 . Each of the task specific panels  28  has a minimum panel depth “A.” The function of panel depth “A” is to permit internal incorporation of electronics, guidance, fuel, and similar features required to interface with missile  66  or any equipment mounted to one of the task specific panels  28 . Panel depth “A” approximately matches a depth of cavity  24  (shown in  FIG. 1 ) such that each task specific panel  28  acts as a structural member when joined with the structure of body section  12 .  
         [0032]     As best seen in  FIG. 5 , a panel  68  is modified to support a torpedo  70 . As shown in  FIG. 6 , a panel  72  is modified to support a sonobuoy package  74  which includes a plurality of sonobuoy delivery tubes  76 . As best seen in  FIG. 7 , a panel  78  is modified to support the pair of rockets  48 . As a further example of a task specific panel  28 ,  FIG. 8  shows a panel  80  modified to incorporate an exemplary synthetic aperture radar module  82  and an electro-optical infra red camera  83 . An exterior face  84  of panel  80  has an expanded panel depth “B” permitting incorporation of radar associated equipment (not shown) within the depth of panel  80 . It should be obvious that  FIGS. 4-8  represent exemplary designs for task specific panels  28 .  FIGS. 4-8  generally describe military applications for the task specific panels  28 . Commercial and civilian uses for task specific panels  28  are also possible, including but not limited to, cameras for surveillance operation, weather-related radar equipment, support racks for carrying wounded personnel, crop spraying nuclear/biological/chemical detection, high value package delivery, and fish finding, etc. The invention is not limited to the devices mounted to a specific task specific panel  28 . Each of the panels identified in  FIGS. 4-8  (as well as panels not shown) are removably fastened to an aircraft of the present invention such that each flight of the aircraft can include a different task specific panel for a different operation of the aircraft.  
         [0033]     In a further preferred embodiment, and referring to  FIG. 9 , a modular aircraft  85  includes a starboard body section pair  86  and a port body section pair  88 . Each of the starboard body section pair  86  and the port body section pair  88  are formed similar to the combination of forward body section  54  and aft body section  56  shown in  FIG. 3 . The starboard body section pair  86  and the port body section pair  88  are arranged in parallel. A forward starboard end piece  90  and a forward port end piece  92  are joined to the starboard body section pair  86  and the port body section pair  88  forward ends, respectively. A forward spacer member  94  is connectably disposed between forward starboard end piece  90  and forward port end piece  92 . An aft end of modular aircraft  85  is similarly formed by an aft starboard end piece  96 , an aft port end piece  98  and an aft spacer member  100 . Providing each of the forward spacer member  94  and the aft spacer member  100  permits incorporation of a payload bay  102 . Based on the increased size and operating weight of modular aircraft  85 , an increased size wing pair  104  and a propeller pair  105  are incorporated therein. Similar to modular aircraft  52  shown in  FIG. 3 , modular aircraft  85  incorporates two task specific panels per side.  
         [0034]     Referring to  FIG. 10 , a modular aircraft  106  includes a rudder section  108  and a horizontal stabilizer pair  110  connectably disposed to an aft spacer member  112 . Similar to modular aircraft  52  shown in  FIG. 3 , modular aircraft  106  incorporates two task specific panels per side.  
         [0035]     For commonality, it is noted that the same geometry and construction features are incorporated in each of the end pieces  34 , forward starboard end piece  90 , forward port end piece  92 , aft starboard end piece  96  and aft port end piece  98  respectively. Similarly, each of the forward body section  54 , aft body section  56 , starboard body section pair  86 , and port body section pair  88  are formed from one or more body sections  12 , shown and described in reference to  FIG. 1 . Each body section  12  is a generally rectangular shaped section incorporating at least one of the vertical propulsion devices  22 . In one preferred embodiment, pulsejet ejector engines are used for vertical propulsion devices  22  in each body section  12 . Alternate vertical propulsion sources can also be incorporated in body sections  12 , including, but not limited to jet engines, rotating propeller sections, or rocket engines. Propellers are described herein for horizontal propulsion of modular aircraft of the present invention, however, alternate horizontal propulsion engines can also be used including jet engines, turbo jet engines, and pulsejet engines. Such horizontal propulsion engine(s) could occupy end piece(s)  34  or task specific panel(s)  28 .  
         [0036]     Referring to  FIG. 11 , a cross section through another embodiment of a body section  12  includes a pulsejet ejector thrust augmentor cavity  120  which is centrally positioned in a body structure  122 . A task specific panel  124  and a task specific panel  126  are shown in each of an installed an a uninstalled position, respectively. A supply/support duct  128  supports task specific panel  124  and a supply/support duct  130  supports task specific panel  126 , respectively. Each of the task specific panels  124  and  126  include a plurality of through-apertures  132  positioned at an upper position thereof. Each of the through-apertures  132  co-axially align with a fastener retention aperture  134  disposed in body structure  122 . An exemplary installation of task specific panel  126  is as follows. The supply/support duct  130  is connected to task specific panel  126  and a tapered end  136  is slidably mated into a tapered slot  138  of body structure  122 . Task specific panel  126  is rotated about panel installation arc C until the panel mates with a seating face  139 . Each of a plurality of fasteners  30  are installed in through-apertures  132  to mate with each of the fastener retention apertures  134  to firmly attach the task specific panel  126 . Task specific panel  124  is shown in its installed position.  
         [0037]     Referring next to  FIG. 12 , another embodiment which is modified from that shown in  FIG. 11  is provided. Only the differences between the embodiment shown in  FIG. 11  and  FIG. 12  will be discussed herein. Body section  140  supports a task specific panel  142  and a task specific panel  144  (shown in phantom). Each of the task specific panels  142  and  144  include an engagement end  146  at opposed ends of the task specific panels. Each engagement end  146  mates with a corresponding engagement slot  148  formed in body section  140 . A plurality of rotational cams  150  are provided which are rotatably connected to body section  140  and rotate about cam rotation arc D from an open position (shown on the right side of  FIG. 12 ) to a closed and latched position (shown on the left side of  FIG. 12 ). Rotatable cams  150  are designed to engage each of the engagement ends  146  to firmly support both ends of task specific panels  142  and  144 . Each task specific panel  142  and  144  can be loaded either horizontally (similar to the direction shown in  FIG. 1 ) or alternately can be slid in a fore/aft direction through select ones of the end pieces  34  via openings (not shown) in the end piece  34 . The openings can themselves be closed or sealed after installation of the task specific panel.  
         [0038]     Referring finally to  FIG. 13 , the steps to construct a modular aircraft of the present invention are described. In a disposition step  200 , a vertical propulsion system is disposed into a body section. At a fastening step  202 , at least one task specific panel is releasably fastened to the body section. In an installation step  204 , a set of task specific equipment is installed on each task specific panel. In a mounting step  206 , a wing pair is mounted to the body section to form the aircraft of the present invention. In a first parallel step  208 , at least two of the body sections are connected together. In a second parallel step  210 , a rounded section or end piece is connected on each free end of the body sections.  
         [0039]     A modular aircraft of the present invention offers several advantages. By incorporating vertical propulsion engines into common body sections, one or more body sections can be joined which provide a general fuselage shape for an aircraft design. By using a commonly shaped end piece, both forward and aft free ends of the body sections are provided with a commonly designed and installed end piece. By spacing two or more parallel aligned body sections, a payload bay can be incorporated as well as common spacer members between the end pieces. By incorporating task specific panels to the sides of each of the body members, each modular aircraft of the present invention can fly multiple missions after removal and reattachment of one of a plurality of mission specific equipment panels. The modular design of the present invention permits multiple uses including military, commercial and private for aircraft of the present invention. By incorporating control and electronic equipment supporting each package mounted from a task specific panel of the present invention, each task specific panel provides a self-contained unit of the necessary task specific equipment associated with the mission. Also, by utilizing aircraft flight control surfaces extending from an aft end of the aircraft as a simplified landing gear, a modular aircraft of the present invention can land and be reused for multiple missions. Maintenance on a modular aircraft of the present invention is also simplified because common component parts are used and are therefore replaceable if damaged or required for alternate missions.  
         [0040]     Materials for a modular aircraft of the present invention are preferably of light weight and high strength. The end pieces are preferably constructed of an elastomeric (i.e., plastic) or fiber reinforced material such as fiberglass, or carbon fiber to minimize weight and provide an inexpensive, replaceable material. Similar materials are also preferably used for the spacer members as well as component parts of the payload bay. Due to the heat generated by the vertical propulsion engines and the need for strong/rigid load bearing structure, one preferred material for the body section(s) is a stainless steel or similar steel, or a metal or alloy which can both withstand the exhaust heat of the vertical propulsion engines and provide structural rigidity for mounting the various components, and supporting the wings of the modular aircraft of the present invention. Materials for the wings are similarly preferably manufactured of elastomeric or composite materials. It should also be noted, however, that the elastomeric materials referred to herein can be replaced by metals such as aluminum or titanium if desirable to provide a higher strength yet still light-weight modular aircraft.  
         [0041]     It is anticipated that although most of the support equipment for a mission is incorporated in the task specific panel, some connectivity between the body section and the task specific panel may be required such as mechanical release mechanisms and/or electronic cabling to support location, guidance data, or fuel for a mission specific piece of equipment, which can be provided from the body section. It is also noted that the payload bay identified herein can be increased in size sufficient that a manned modular aircraft of the present invention can be provided. This will require some modification to the forward spacer member  94  (shown in  FIG. 9 ), for example to include a windshield (not shown) for visibility. A landing gear set similar to that used for common military or commercial aircraft can also be incorporated in a modular aircraft of the present invention, particularly if manned flight is required.  
         [0042]     A modular aircraft of the present invention, in one preferred form, may comprise a subsonic speed aircraft. The capability provided by the vertical propulsion engines provides each modular aircraft of the present invention with the advantage of a vertical or nearly vertical takeoff operation. This greatly increases the range of use for the modular aircraft of the present invention to areas where runways are not available as well as to those areas where runways are available. The preferred use of pulsejet ejector engines in a vertical takeoff aircraft is disclosed in co-pending U.S. patent application Ser. No. 10/245,145 commonly assigned to the assignee of the present invention, and filed on Sep. 16, 2002, the disclosure of which is incorporated herein by reference. The use of pulsejet ejector engines in vertical takeoff aircraft permits a low cost, low maintenance modular aircraft of the present invention both a vertical takeoff and landing capability as well as a limited hovering capability.  
         [0043]     A modular aircraft as described herein is exemplary in that the invention can be applied to any mobile platform, and particularly to any flight capable mobile platform. The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.