US20110088586A1

US20110088586A1 - Velocity control and terrain selection for gravity moderation

Info

Publication number: US20110088586A1
Application number: US12/924,322
Authority: US
Inventors: Jerry Huang; C. Hwa Chang; Lehan Huang; Shawn Huang
Original assignee: Tufts University
Current assignee: Tufts University
Priority date: 2009-10-21
Filing date: 2010-09-24
Publication date: 2011-04-21
Also published as: CN102040011A

Abstract

A system, method, and apparatus is described for providing a reduced or moderated gravity environment in a terrestrial payload. The system includes the evaluation of terrain to support an appropriately shaped vehicle guide, the construction of a vehicle guide, the provision of a high-speed vehicle and a control system adapted to control a motion of the vehicle across the vehicle guide with a specific velocity profile so as to produce a moderated gravity environment.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. provisional patent application No. 61/253,596 filed on Oct. 21, 2009, the disclosure of which is herewith incorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to establishing controlled environmental conditions and more particularly to establishing controlled effective gravitational conditions within an operating environment.

BACKGROUND

It is known that various materials, technical processes, and biological systems exhibit different behavior in microgravity as compared with typical Earth gravity. An early example of this understanding is revealed in the development of shot-towers in the 1800s for producing lead projectiles of substantially uniform spherical aspect. More recently, similar free-fall systems have been employed in the manufacture of substantially spherical ball bearings. Likewise, the entertainment value of experiencing a substantially inertial environment has been known for some time, as expressed in various amusement park rides.
Since the early days of the space program, NASA has conducted reduced gravity experiments in aircraft in parabolic flight. Longer duration microgravity experiments have been conducted in orbital and extra-orbital systems.
More recently, various concerns have offered reduced gravity test-bed facilities in aircraft on a commercial basis. These flights exert high stresses on aircraft structural members, and provide the desired reduced gravity for only short durations of approximately 20 seconds. Airborne low gravity environments are understood to be expensive and spaceborne environments are extremely expensive. These and other factors limit the usefulness of existing systems.
It is worth noting that advertising related to commercially available airborne systems explicitly asserts that such systems are “unique in their ability to provide a suborbital microgravity environment.” The present invention has been developed in the face of such contrary teachings. Notwithstanding the well-known desirability of having access to a low gravity environment for various technical processes, the possibility of maintaining a low gravity condition in a terrestrial technical environment over a substantial time interval has not been appreciated.

SUMMARY

Through reflection and careful consideration, the inventors have come to understand problems and opportunities not previously known or understood in the technology discussed above. For example, and as will be discussed in additional detail below, it would be useful to have increased access to a moderated gravity environment at relatively low cost. Based on this discovery, the inventors have conceived and developed novel solutions including inventive apparatus, methods, systems and techniques for providing a moderated gravity environment optimized for cost and duration. For example, a terrestrial system incorporating the beneficial use of existing features of a geographic terrain can provide surprising and unexpected benefits. The invention, encompassing these new and useful solutions and improved devices, is described below in its various aspects with reference to several exemplary embodiments including a preferred embodiment.
Further to the discussion above, a limited number of terrestrial moderated-gravity environments are known. These include amusement park rides and similar entertainments (e.g., bungee jumping) and some astronaut training devices. As also noted above, shot-towers and some airborne systems have been applied to briefly provide a reduced apparent gravity environment for technical and experimental processes. For example, aircraft have been flown at high speed through a parabolic trajectory so as to provide a brief period of substantially inertial travel. During these brief time intervals, occupants and equipment within the aircraft experience microgravity or “weightlessness”.
The present invention involves the preparation and use of terrestrial apparatus in which an environment having a moderated gravity characteristic is available for various purposes including entertainment, manufacturing, and experimentation, among others. In various aspects, the invention includes the preparation of specialized moving terrestrial apparatus, and/or the exclusive or shared reconfiguration of existing or planned apparatus, for providing the subject substantially inertial environment. In certain aspects, the invention includes systems, methods and tools for terrain analysis and system planning where existing topographical features of a particular region are beneficially employed.
One example of such a system and apparatus includes a high-speed rail system, or other terrestrial guided vehicle, where a mechanical rail or other vehicle guide is located in a selected terrestrial region. The system includes a high-speed train or other vehicle, and apparatus for controlling a motion of the vehicle so as to produce the desired moderated gravity environment. In certain aspects, the invention is adapted to use particular macroscopic features of existing high-speed rail technology, and even existing high-speed rail equipment.
A system method and apparatus according to the present invention provides terrestrial access to a microgravity environment. One such device includes gravity moderation apparatus with a terrestrial vehicle that has a passenger cabin or other internal cavity. The cabin can accommodate a payload that includes passengers and/or technical apparatus.
In certain aspects, the invention includes a leveling mechanism. The leveling mechanism works actively and/or passively to maintain a passenger cabin or other payload in a particular orientation, over a particular time interval, with respect to a horizontal plane. Where, for example, gravity is reduced but still perceptible, payload leveling facilitates technical processes and improves passenger comfort.
In certain other aspects, the invention includes a method of providing a moderated gravity environment including diverting a high-speed rail vehicle from a regular intercity route onto a secondary route. The secondary route includes a guide structure. The guide structure traverses a substantially parabolic terrain region so that the guide structure defined a substantially parabolic pathway. In further aspect, the invention includes operating the high-speed rail vehicle according to a preferred velocity profile across the substantially parabolic pathway to produce the desired moderated gravity conditions.
In still other aspects, the invention includes a method for providing a reduced gravity environment that includes evaluating a region of terrain between a departure location and a destination location to identify a desirable terrain feature. In some examples, the desirable terrain feature defines a generally parabolic contour. It should be noted that other contours are also desirable in particular embodiments of the invention.
In addition to discovering the desirable terrain feature, the invention includes constructing a guide structure adjacent to the preferred terrain feature. The guide structure is arranged to control a trajectory of a vehicle as, for example, a train track controlled the trajectory of a train. In certain embodiments of the invention, the trajectory includes a substantially parabolic trajectory portion.
According to certain aspects, the invention includes movably coupling the vehicle to the guide structure, and in a still further aspect, the vehicle has a payload coupled to it. Thereafter, a velocity of the vehicle across the guide structure is controlled according to a preferred velocity profile. In this way the vehicle and its payload experience modified gravity. It should be noted that the modified gravity conditions can persist across positive slope and negative slope portions of the parabolic region.
These and other advantages and features of the invention will be more readily understood in relation to the following detailed description of the invention, which is provided in conjunction with the accompanying drawings.
It should be noted that, while the various figures show respective aspects of the invention, no one figure is intended to show the entire invention. Rather, the figures together illustrate the invention in its various aspects and principles. As such, it should not be presumed that any particular figure is exclusively related to a discrete aspect or species of the invention. To the contrary, one of skill in the art would appreciate that the figures taken together reflect various embodiments exemplifying the broader invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows, in schematic form, a portion of a high-speed guided-vehicle system according to certain aspects of the invention;

FIG. 2 illustrates a portion of an exemplary system according to principles of the invention in schematic cross-sectional form;

FIG. 3 illustrates a portion of an exemplary system according to principles of the invention in schematic topographical form;

FIG. 4 shows an aspect of a theoretical vehicle path according to principles of the invention in graphical form;

FIG. 5 shows a further aspect of a theoretical vehicle path according to principles of the invention in graphical form;

FIG. 6 shows a still further aspect of a theoretical vehicle path according to principles of the invention in graphical form;

FIG. 7 shows, in block diagram form, a portion of a control system according to certain aspects of the present invention;

FIG. 8A-8C shows, in schematic elevation, various aspects of an orientation subsystem according to the present invention; and

FIG. 9A-9B shows, in schematic elevation, various further aspects of an orientation subsystem according to the present invention.

DETAILED DESCRIPTION

The following description is provided to enable any person skilled in the art to make and use the disclosed invention and sets forth the best modes presently contemplated by the inventors of carrying out their invention. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the substance disclosed.
As noted above, orbital and airborne systems have previously been used to provide microgravity environments for long duration and short duration activities respectively. In addition, shot-towers, which allow for very short duration microgravity conditions, have been used in the manufacturing of spherical metal shot since the 1800s, and subsequently ball bearings. The disadvantages of these systems are well known. In particular, the very short durations available in shot-towers, the relatively short durations and high cost of airborne environments, and the extraordinarily high cost of orbital environments preclude these solutions for many potential applications.
Despite this condition having persisted for many years, and the consequent long known but unfulfilled need for superior moderated gravity solutions, it has been left to the present inventors to develop a new perspective on the existing problems and conceive the present inventive solutions. In particular, certain embodiments of the present invention involve using high-speed rail technology, including novel system features, to provide a terrestrial working environment having moderated gravity over intermediate time intervals.
FIG. 1 shows, in schematic form, a portion of a high speed rail system 100. As illustrated, the system 100 includes a vehicle 102 having a cabin 104 and adapted to be movably coupled to a guiding structure 106. According to the illustrated embodiment of the invention, the guiding structure 106 includes a tubular tunnel 108 and a plurality of guides, e.g., 110, 112, 114, 116. Although illustrated generically as rails, one of skill in the art will readily appreciate that guides 110, 112, 114 and 116 are intended to represent a guiding mechanism appropriate to the demands of a particular application. Accordingly, as discussed in additional detail below, the guiding mechanism may include any of a variety of devices such as rails of various materials, magnetic support devices, and such other support mechanisms as currently exist or may be developed.
According to certain aspects and embodiments of the invention, the high-speed rail system 100 includes a vehicle control subsystem 120, at least a portion of which is disposed within the vehicle 102, and a guide control subsystem 122. The vehicle control subsystem 120 and the guide control subsystem 122 are coupled through a communications subsystem 124 to a system controller 126.
In certain embodiments, the system controller 126 is coupled to a storage device 128 and a user interface subsystem 130. According to certain aspects of the invention, the user interface subsystem 130 allows the communication of status and supervisory information between the system as a whole and certain supervisory personnel. The various subsystems allow controlled operation of the vehicle 102 within the guiding structure 106 to produce an inertial environment with moderated effective gravity over certain time intervals.
FIG. 2 shows, in schematic form, a portion of a high-speed rail system 200 according to certain aspects of the invention. The illustrated embodiment shows, in cross-section, a terrain profile 202 selected for having a generally parabolic configuration. It should be noted that the terrain profile shown is provided purely for illustration and does not represent an actual geographic region. Nevertheless, it will be understood by one of ordinary skill in the art that many locations throughout the world will be appropriate to particular applications of the present invention. In addition, it should be noted that the illustrated terrain profile 202 is not precisely parabolic, but is generally parabolic and well adapted to support a substantially parabolic vehicle guide 204 over an extended geographic distance.
The topological differences between the terrain profile 202 and the desired parabolic configuration of the vehicle guide 204 are accommodated by the use of tunneling, trestles, and other civil engineering technologies, as known in the art. Accordingly, a tunnel 206 is provided where a portion of the desired parabolic path of the vehicle guide 204 is substantially below a corresponding elevation 208 of the terrain profile 202. The term “tunnel” should be understood to include longitudinal cavities excavated through bulk terrain, as well as enclosed passages constructed by trenching and backfilling, self-supporting conduits, and other alternatives available in the art.
Conversely a trestle 218, or other elevated support, is employed where a portion of the desired parabolic path of the vehicle guide 204 is substantially above a corresponding elevation 212 of the terrain profile 202. As will be further discussed below, the trestle or other support is provided, in certain embodiments, with an enclosure providing an effective elevated tunnel. Accordingly, in certain embodiments of the invention, a partially or substantially evacuated environment is available within a substantially continuous tunnel structure over a portion of the vehicle guide 204.
In the illustrated embodiment, a vertical projection of the vehicle guide 204 into the horizontal plane, between an injection point 214 and a recovery point 216, has a length 210 on the order of 3 km. in other embodiments, the vertical projection has a length 210 on the order of 10 km. Consequently, the illustrated device is quantitatively and qualitatively different from small-scale apparatus such as shot-towers and amusement park rides which provide inertial behavior over distances that are orders of magnitude shorter, and timescales that are correspondingly limited.
FIG. 3 illustrates a portion of a cartographic view 300 of a gravity moderation device according to an exemplary embodiment of the invention. In the illustrated embodiment, a vehicle guide system 302 is disposed between an origin location 304 and a destination location 306. The vehicle guide system 302 can include a track, an electromagnetic device including, for example a superconducting electromagnetic device, or any other apparatus configured to guide the vehicle along a defined pathway so as to produce a moderated gravity condition. As noted above, an exemplary vehicle guide is supported by a generally parabolic region of terrain between an injection point and a recovery point.
In one embodiment of the invention, locations 304 and 306 correspond to respective cities. In another embodiment of the invention, one of locations 304 and 306 corresponds to a popular destination such as, for example, an airport, a ferry terminal, or a casino or other resort.
In the illustrated embodiment, the vehicle guide system 302 includes a first portion 308 disposed along a first respective route portion and a second portion 310 disposed along a second respective route portion. The first route portion, and vehicle guide portion 308, traverses substantially conventional terrain. The second route portion, and vehicle guide portion 310, includes a substantially parabolic path (or other effective path) 312 according to aspects of the present invention.
According to principles of the invention the second route portion, supporting vehicle guide portion 310, traverses terrain 314 that generally conforms to the desired parabolic path 312 and is adapted to support the corresponding substantially parabolic region of the vehicle guide. In the illustrated embodiment, vehicle guide portion 310 follows a substantially parabolic contour between an injection point 316 and a recovery point 318. One of ordinary skill in the art will readily appreciate that, in some embodiments, the vehicle guide 302 is substantially symmetrical between at least injection point 316 and recovery point 318. Consequently injection point 316 and recovery point 318 can equally well be recovery point and injection point respectively.
Also shown on the cartographic view 300 are the respective locations of first 320 and second 322 airlocks. As will be discussed in additional detail below, these airlocks are adapted to preserve a condition of reduced atmospheric pressure within an enclosed vehicle guide portion between the airlocks. It should be understood that in certain embodiments of the invention, multiple airlocks at respective multiple locations are configured to provide more effective control of atmospheric pressure within the enclosed portion of the guide system. It is also understood that, in some embodiments of the invention, reduced atmospheric pressure is maintained within an enclosed vehicle guide system over substantially the entire distance between the origin 304 and destination 306 and along vehicle guide portion 308 as well as vehicle guide portion 310.
In certain embodiments of the invention, each airlock includes a respective pair of locking gates to keep the air pressure inside the tunnel (e.g., 108 in FIG. 1) constant and low. Each pair of gates forms and encloses a chamber, entrance chamber or exit chamber, having a relatively short length within the tunnel. Let us name the locking gates A, B, C and D in the direction of vehicle.
The passengers can board the vehicle at a station anywhere outside the tunnel. The vehicle enters the entrance chamber with locking gate A open and locking gate B closed. Once the vehicle is in the entrance chamber, locking gate A closes and the air inside the chamber is brought to the same pressure as in the tunnel. Then locking gate B is opened and the vehicle accelerates into the tunnel for an entertaining ride. The same procedure in reverse order is used when the vehicle exits the tunnel.
In addition, cartographic view 300 shows a first substantially linear vehicle guide portion 324 disposed between airlock 320 and injection point 316 and a second substantially linear vehicle guide portion 326 disposed between recovery point 318 and second airlock 322. Substantially linear vehicle guide portions 324 and 326 allow for acceleration and deceleration respectively of a guided vehicle.
Of course, the configuration illustrated in FIG. 3 is only one of a wide variety of possible configurations. Accordingly, in certain embodiments of the invention, multiple parabolic regions are included and are adapted to be traversed sequentially. In general, the parabolic portions of the vehicle guide are disposed in a substantially vertical plane, however the azimuth of any particular parabola can be disposed according to an advantageous feature of the available terrain and other requirements of a particular application, including but not limited to, a desirable efficiency of a route between origin and destination points.
According to principles of the invention, the vehicle speed at each point on the vehicle guide is computer-controlled by the resultant (vector sum) of horizontal and vertical components of the computed velocity so that the desired gravitational acceleration, or G force, inside the vehicle can be achieved. For clarity the characteristics of a particular exemplary system will now be described in additional detail.
For easy comprehension of the concepts, we use scientific or metric measurements and the approximation of 9.8 m/sec²as the value of g, the gravitational acceleration on the surface of the Earth.
A parabolic equation for the rail routes can be derived as follows: Given a constant horizontal velocity v₀, the horizontal distance x traveled in time t is
x=v₀t
The vertical distance traveled in time t is y=−½ g t², where the minus sign serves to indicate the downward direction. By eliminating t, we get
y=−g/(2v ₀ ²)·x ² equation (1)
The parabolic routes will be governed by this mathematical equation, where x is the horizontal coordinate in meters, y is the vertical coordinate in meters and g is the gravitational acceleration near the surface of the Earth. The value of g is:
g=−9.8 m/sec²
v₀is the horizontal component of the velocity. There is one v₀for a particular parabola.
The derivative of equation (1) with respect to x is:
y′=dy/dx=−(g/v ₀ ²)·x equation (2)
y′ is the slope of the parabola at any point x. Since v_y=dy/dt, v_x=dx/dt, we have:
v _y /v _x =dy/dx=−(g/v ₀ ²)·x equation (3)
The vehicle velocity at each point on the path to achieve 0 G and reduced G can be derived as follows:

For the Zero G Case:

y′=v _y /v _x=−(g/v ₀ ²)·x
where horizontal speed remains constant v_x=v₀thus v_y=−(g/v₀)·x
Each parabola has a unique v₀horizontal velocity. Thus by vector addition of the x- and y-components of the velocity, we get the vehicle velocity in the system at any point x for producing weightlessness.
v=v _x +v _x
Magnitude of v=|v|=(v ₀ ²+(g ² /v ₀ ²)·x ²)^1/2
Referring now to FIG. 4, which shows a theoretical vehicle path 400 in graphical form, the dashed curves 402 and 404 are not part of the parabola path 406. g is 9.8 meter/sec². The total time period during which an effective 0 G environment is available, in this example, is 49 seconds. The vehicle is to accelerate to the specified speeds along the acceleration path 402. The vehicle is to slow down, or prepare for another 0 G ride, along further path 404.

For the Reduced G Case:

Since the system has to absorb part of the gravitational acceleration in order to leave the so called “residual” acceleration inside the cabin as the reduced gravity, for example, lunar gravity p=⅙-16%, the vehicle has to be “falling downwards” with
(1−p)g meters/sec², where g is approximately 9.8 meters/sec².

Now let

v _h =v ₀(1−p)^1/2 equation (4)
where v₀is the horizontal velocity for 0 G and
v _y =−g((1−p)/v _h)x, equation (5);
Please note that v_his a constant and v_yis not. It is readily demonstrated that
y=−½(1−p)gt ².
That is to say that we achieve the reduced gravity (1−p)g
$\begin{matrix} y = \int v_{y} \partial t \\ = \int - g ((1 - p) / v_{h}) x \partial t \\ = \int - g ((1 - p) / v_{h}) v_{h} t \partial t \\ = \int - g (1 - p) t \partial t \\ = - \frac{1}{2} (1 - p) t^{2} \end{matrix}$ $from equation (4)$ $x = v_{h} t$
This can be considered from another perspective as follows. Let v_hrepresent the required horizontal velocity for achieving a reduced gravity (1−p)g. Equation (1) can not be changed because the parabola track path is fixed. That is to say the coefficient −g/(2v₀ ²) is also fixed. Multiplying both denominator and numerator of the coefficient by the factor of (1−p), we get
−g(1−p)/(2v₀ ²(1−p))
Now v₀ ²(1−p) is part of the coefficient that needs to be the new horizontal velocity. Squaring v_h, we get
v _h ² =v ₀ ²(1−p) equation (6)
thus
v _h =v ₀(1−p)^1/2, where v₀is the horizontal velocity for 0 G
The vertical component of the velocity v_ycan be derived from the derivative equation (2),
y′=v _y /v _h =−g/v ₀ ² ·x
We know from equation 6 above v_h ²=v₀ ²(1−p), therefore v₀ ²=v_h ²/(1−p)
By replacing v₀ ²we get
$\begin{matrix} v_{y} = (- g / v 0^{2} \cdot x) v_{h} \\ = - g (1 - p) / v_{h} \cdot x \end{matrix}$ $v_{y} = \frac{- g (1 - p)}{v_{h}} \cdot x$
v_yis the vertical component of the vehicle velocity at each point.
Again by vector addition of the x- and y-components of the velocity, we get the vehicle velocity within the system at any point x for simulating a reduced gravity.
v=(v _h ² +v _y ²)^1/2=(v ₀ ²(1−p)+(g ²(1−p)² /v _h ²)·x ²)^1/2
since v_h ² =v ₀ ²(1−p)
v=(v ₀ ²(1−p)+(g ²(1−p)/v ₀ ²)·x ²)^1/2
Thus any other reduced gravity condition can be simulated on the fixed track path accordingly. A parabolic vehicle path provides the most efficient and effective result. In fact, however, the same 0 or reduced gravity condition can be achieved on a track of any shape by proper control of vehicle speed (i.e., vehicle acceleration).
For lunar gravity, 16% or ˜⅙ of Earth's gravity is to be perceived in the cabin. The system must use up or “absorb” 1−p=⅚ of the Earth's gravitational acceleration so that the passenger can experience the ⅙ of Earth's gravity (the gravity on the Moon's surface). Suppose we have a v₀=270 parabola track.
v _h =v ₀(1−p)^1/2=246m/sec
v _y=−(g(1−p)/v _h)·x=−0.0339×m/sec
For Martian gravity, 38% or ⅜ of Earth's gravity is to be perceived in the cabin. The system must use up or “absorb” 1−p=⅝ of the Earth's gravitational acceleration so that the passenger can experience the 38% of Earth's gravity (gravity on Mars). Suppose the vehicle is on a v₀=245 parabola route.
v _h =v ₀(1−p)^1/2=193.7 m/sec
v _y =−g(1−p)/v _h ·X=−0.03226×m/sec
The system can be operated as an intercity transit. A half G vehicle with a horizontal velocity v_hof 191 meters/sec on a v₀=270 parabola track path can be reasonably used as a passenger transit.
Several possible parabolic route constructions for a height of 3 km are illustrated in FIG. 5 and FIG. 6. Such embodiments would have horizontal velocities of 245 m/s, 260 m/s and 270 m/s respectively.
Other combinations of the parabolas are possible as long as each section of the track is governed by equation (1) and connected by a smooth curved path from one section to another. For example, as shown in FIG. 5, a transition 502 can be effected from one parabola 504 to another 506 at any point 508 on parabola to form a track 500. FIG. 6, shows a transition 522 from one parabola 524 to another 526 at an apex 528 to form an asymmetrical path. In the illustrated embodiment a further transition 530 is shown from parabola 526 back to parabola 524 at a further transition point 532. Transition from one vertical plane to another plane can also be implemented in certain embodiments.
Further aspects of a system and method according to principles of the invention will now be described with reference to the foregoing disclosure and additional FIGS. 7 to 9B.
As discussed above, depending on the particular conditions desired, it may be necessary to achieve vehicle velocities on the order of several hundred meters per second. Some vehicles can achieve this performance in ambient atmospheric conditions. As previously noted, however, certain embodiments of the invention include operating a vehicle within a substantially enclosed chamber, where the chamber has a controlled atmosphere. Accordingly, and with reference to FIG. 1, certain embodiments of the invention include operating the guided vehicle within a tubular structure having a generally longitudinal interior cavity that is substantially evacuated during, at least, a transit time interval of the vehicle.
For purposes of this disclosure, such a tubular structure is referred to as a tunnel (e.g., 106 in FIG. 1). It should be understood, however, that the chamber may be constructed by excavation, construction, or both, with any appropriate material or combination of materials. Accordingly, the tunnel includes one or more of a concrete material of any appropriate composition, a metallic material including any appropriate alloy, a polymer material including polymer material reinforced with glass, carbon, or any other appropriate reinforcement, and any other structural and/or sealing material as may be appropriate to achieve the objectives presented herewith.
Suitable metal or metallic alloys may include steel, stainless steel; aluminum; an alloy such as Ni/Ti alloy; any amorphous metals including those available from Liquid Metal, Inc. or similar ones, such as those described in U.S. Pat. No. 6,682,611, and U.S. Patent Application No. 2004/0121283, the entire contents of which are incorporated herein by reference.
As noted, various polymers may be used for structural members and for sealing a tunnel according to the invention. Suitable polymers include polyethylene, polypropylene, polybutylene, polystyrene, polyester, acrylic polymers, polyvinylchloride, polyamide, or polyetherimide like ULTEM®; a polymeric alloy such as Xenoy.RTM. resin, which is a composite of polycarbonate and polybutyleneterephthalate or Lexan.RTM. plastic, which is a copolymer of polycarbonate and isophthalate terephthalate resorcinol resin (all available from GE Plastics), liquid crystal polymers, such as an aromatic polyester or an aromatic polyester amide containing, as a constituent, at least one compound selected from the group consisting of an aromatic hydroxycarboxylic acid (such as hydroxybenzoate (rigid monomer), hydroxynaphthoate (flexible monomer), an aromatic hydroxyamine and an aromatic diamine, (exemplified in U.S. Pat. Nos. 6,242,063, 6,274,242, 6,643,552 and 6,797,198, the contents of which are incorporated herein by reference), polyesterimide anhydrides with terminal anhydride group or lateral anhydrides (exemplified in U.S. Pat. No. 6,730,377, the content of which is incorporated herein by reference) or combinations thereof.
In addition, any polymeric composite such as engineering prepregs or composites, which are polymers filled with pigments, carbon particles, silica, glass fibers, conductive particles such as metal particles or conductive polymers, or mixtures thereof may also be used. For example, a blend of polycarbonate and ABS (Acrylonitrile Butadiene Styrene) may be used
One of skill in the art will understand that a variety of systems and apparatus are advantageously employed in maintaining the specified vehicle velocity profile, as well as environmental conditions within the tunnel system and the vehicle. FIG. 7 shows, in block diagram form, a portion of a monitoring and control subsystem 600 for a moderated gravity system according to principles of the invention. The monitoring and control subsystem 600 includes a first portion 602 principally related to the monitoring and control of the tunnel and track system and to the position of one or more vehicles within the tunnel and track system. A second portion 604 is principally related to monitoring and control of an individual vehicle. A communication subsystem 606 provides status and control communications between the control subsystem 600, and the track control system 602 and vehicle control 604 subsystems.
The track and tunnel control subsystem 602 includes and controls a variety of further subsystems including, for example, a tunnel atmosphere control subsystem 608. The tunnel atmosphere control subsystem, in turn, includes and controls an evacuation pump subsystem 610, an airlock control subsystem 612 and an emergency re-pressurization subsystem 614.
In certain embodiments of the invention, the evacuation pump subsystem controls one or more evacuation devices. The evacuation devices operate to reduce atmospheric pressure within a tunnel of the apparatus so as to reduce aerodynamic friction experienced by the vehicle during operation.
The airlock control subsystem 612 controls various operational aspects of system airlocks provided at the entrance and exit of the tunnel. For example, the airlock control system 612 controls the opening and closing of external doors and internal doors to allow passage of a vehicle into and out of the tunnel without substantially degrading low atmospheric pressure conditions within the tunnel. In certain embodiments of the invention, the airlock control subsystem 612 also controls one or more airlock evacuation devices. The airlock evacuation devices are arranged to pump down pressure within an airlock chamber so as to further reduce the introduction of air into a tunnel along with an entering or exiting vehicle.
As indicated, in some embodiments, the invention includes an emergency repressurization subsystem. The emergency repressurization subsystem operates to detect an emergency condition and open a valve or otherwise restore substantially normal atmospheric conditions within a tunnel of the system. Thus, for example, if cabin pressure is lost or degraded for a vehicle within the tunnel, substantially normal ambient atmospheric conditions can be rapidly introduced into the tunnel so as to ameliorate any potential danger to vehicle passengers. In addition, under certain circumstances the reintroduction of an ambient atmosphere within the tunnel can serve to assist in the emergency deceleration of a system vehicle, as in the event of a braking system emergency, for example.
As illustrated, the track control subsystem 602 also includes and controls a scheduling and dispatch subsystem 616. The scheduling and dispatch subsystem 616 receives operator input and calculates appropriate system responses including, for example, scheduling and controlling departure times. Concurrently, the illustrated safety oversight subsystem 618 serves to report on system conditions and to automatically ensure that system constraints governing safe operational speeds and inter-vehicular distances are maintained.
As indicated above, the control system 600 also includes a vehicle control subsystem 604. The vehicle control subsystem 604 controls the attributes and operation of various operative subsystems onboard a particular vehicle. For example, the vehicle control subsystem includes and controls a motion control subsystem 620 that, in turn, includes and controls a drive system 624 and a braking system 622. The drive system 624 includes, in various embodiments, a system for the control of electric motors, linear electric motors, and any other appropriate propulsion device. The braking system 622 includes, in various embodiments, a system for the control of friction brakes, dynamic regenerative braking, and any other appropriate braking device. In various embodiments the control system includes computer processors, memories, interface equipment, storage devices, digital to analog converters, amplifiers and motors. In various embodiments of the invention the control system includes software and firmware adapted to control an operation of such computer processors and the described ancillary equipment.
As illustrated, the vehicle control system 604 also includes and controls a personnel support subsystem 626 and a technical support subsystem 628. Thus, to the extent that a vehicle operates within a substantially evacuated chamber, and to the extent that personnel and equipment associated with the vehicle may require normal environmental conditions, a particular embodiment of the invention includes a vehicle having a pressurized cabin, pressurization equipment and control equipment adapted to control an atmosphere within the pressurized cabin.
The personnel support subsystem 626 and technical support subsystem 628 control various facilities including those which maintain an appropriate atmospheric composition and pressure within the pressurized cabin of the vehicle. In various embodiments, the personnel support subsystem 626 also controls, for example, water and wastewater handling systems, environmental temperature control systems, lighting systems, and other systems appropriate to a particular application or device. Also in various embodiments, the technical support subsystem 628 controls technical water and wastewater handling systems, process chemical handling and disposal systems, technical ventilation systems, technical power systems, computational systems, and other systems appropriate to a particular application or device.
FIG. 8A-8C shows additional aspects of a system according to the invention including a vehicle having an apparatus for substantially leveling, or otherwise adjusting an orientation of, an interior region of a vehicle cabin. In light of the teachings above, one of skill in the art will recognize that the tunnel and/or guide device sections shortly before and after the injection and recovery points respectively are arranged at a 45° angle for a 245 m/s parabola.
According to one embodiment of the invention the vehicle 800 has a pressurized cabin 802, similar to that of a jetliner, for example. In the illustrated embodiment, the cabin 802 is pivotally coupled to a chassis 804. The chassis 804 is adapted to be movably coupled to the guide system so as to maintain an orientation substantially tangent to the guide system as the vehicle 800 traverses the guide system.
As shown in FIG. 8B, a leveling device 806 is provided to adjust an orientation 808 of the cabin 802 with respect to the chassis 804 so as to make the passengers comfortable, notwithstanding the steeply sloping track. In other applications and embodiments of the invention, having a substantially stable and level cabin is important for providing a useful working environment for conducting technical processes and/or experimentation.
In various embodiments of the invention, the leveling device includes an appropriate linear actuator 810. The linear actuator 810 can include one or more of a hydraulic cylinder, a pneumatic cylinder, a linear electric motor, a rotary electric motor, a lead screw, a ball screw, a rack and pinion device, and any other device adapted to provide the forces requisite to displace a portion of the cabin 802 with respect to the chassis 804. According to certain aspects of the invention, the linear actuator 810 is pivotally coupled to the chassis 812 and pivotally coupled to the cabin 814 so as to allow the indicated adjustment of orientation 808.
FIG. 8C shows that a further linear actuator 820 is included in certain embodiments of the invention so as to allow a symmetrical pivotal adjustment of orientation 822 of the cabin 802 in the opposite direction with respect to the chassis 804. One of skill in the art will appreciate that the adjustment of orientation 808, 822 is performed automatically under, for example, computer control during operation of the vehicle 800. Consequently, for the properly configured system, adjustment of cabin orientation 808, 822 is substantially imperceptible to an occupant of the cabin 802 and proceeds so as to immediately compensate for a change in track orientation as the vehicle 800 proceeds along the guide structure.
This automatic adjustment of the cabin orientation 808, 822 can be effected by various empirical and analytical approaches including by performing the following calculations. The slope at each point on the parabolic track is known from equation (2)
y′=−(g/v ₀ ²)·x
Thus the angle of elevation can be determined by the following equation:
θ=tan⁻¹(−g/v ₀ ² ·x) equation (7)
In the illustrated embodiment, the passenger cabin 802 and the chassis 804 are connected by actuators (exemplified as hydraulic lifts) 810, 820 to compensate for an angle of elevation of the underlying track. The cabin 802 can be lifted on either end as shown in FIG. 8B-8C. The angle of elevation 808, 822 of the cabin is adjusted to maintain, in combination with the floor design, an effective gravitational force substantially normal 824, 826 to the floor of the passenger cabin. In certain embodiments of the invention, the orientation of the cabin can be adjusted by the lift up to π/8 or 22.5°. In other embodiments, of the invention, the orientation of the cabin can be adjusted by up to π/4 or 45° in either direction. Accordingly, when gravity is nonzero, a passenger can walk on a horizontal surface. Also, a scale can be used on the horizontal floor to measure passenger weight readings effectively equal to those on the Moon or Mars.
FIGS. 9A-9B illustrate a further aspect of the invention including a another device 900 for maintaining a level interior floor in a cabin of the vehicle. As shown in FIG. 9A the vehicle has a cabin portion 902 and a chassis portion 904. The cabin portion 902 includes a floor 906 with a plurality of steps or terraces e.g., 908. In the illustrated embodiment, a vehicle seat 910 or other support device is coupled to an exemplary terrace. As shown, when the cabin is not elevated, the terrace 908, and consequently the vehicle seat 910, is disposed at an oblique angle with respect to a horizontal plane. Consequently, when an orientation of the cabin is adjusted, as described above, a smaller adjustment will achieve a level orientation of the terrace floor. Naturally these particular features are not needed for zero g only operations because there is no sense of up or down during weightlessness.
A fixed terrace reduces the required cabin rotation required to level the floor on one side of a parabola, but opposes the leveling effect on the other side of the parabola. Consequently, in some embodiments of the invention, an apparatus is provided to rotate the terrace during operation of the vehicle. According to this arrangement, a rotation of the terrace sums linearly with a rotation of the cabin to produce an overall desired rotation without excessive cabin rotation. By minimizing cabin rotation, a tunnel having a relatively smaller overall size can accommodate the vehicle.
Since cabin rotation is entirely predictable with respect to vehicle guide angle, a portion of the tunnel at a particular location can be constructed to have adequate ceiling height to accommodate any vehicle rotation necessary for that location. Generally speaking, in such an arrangement, tunnel height will be largest where the grade of the vehicle guide is steepest. In addition, by reducing tunnel size were rotation is unnecessary, both overall construction costs and the operational costs of maintaining a low pressure atmosphere can be reduced.
FIG. 9B shows an exemplary configuration in which the passenger cabin 902 is rotated with respect to the chassis 904 by an actuator 912. As shown, a plurality of terraces 907, 908, 909 have respective floors disposed at an oblique angle 918 with respect to a floor plane 920 of the vehicle. Consequently, a cabin rotation angle 922 is sufficient to level the terrace floor is even though rotation angle 922 is less than the local vehicle guide grade 924.
In some embodiments, strong accelerations will be achieved during operation of the vehicle before and after a moderated gravity time interval. In certain embodiments, the terraces are further adapted to adjust passenger seat orientation during rapid acceleration and deceleration. In addition, rotating seats can be provided that can be turned, manually, semi-automatically or fully automatically, about a vertical axis to ensure that optimum passenger orientation is maintained during acceleration and deceleration. Consequently, stresses on passenger skeleton and musculature can be reduced during normal operation and also during any emergency deceleration. In some embodiments of the invention, by properly orienting a passenger seat, the need for a seatbelt, or other restraint, can be reduced or eliminated.
In addition to the orientation adjusting features discussed above, it will also be advantageous to provide antivibration systems in relation to certain embodiments and aspects of the invention. Accordingly, where passenger comfort, or the success or efficiency of technical processes, will benefit from such an investment, a vehicle according to the invention will include a passive or active damping or other antivibration system for absorbing, dissipating, and/or counteracting ambient vibration within a vehicle. In certain embodiments, the antivibration system will include pneumatic and/or hydraulic shock absorbers.
In other embodiments, the antivibration system will include mechanical springs such as, for example, coil springs, the spring, portion springs, or other elastic arrangements. Elastomeric material will be beneficially employed in some embodiments of the invention to provide elasticity and energy damping.
In still other embodiments of the invention, active damping and vibration cancellation using various electro-mechanical systems will be employed. Accordingly, in some embodiments of the invention, computer-controlled electromechanical servo systems including, for example, accelerometers digital or analog processing systems, and/or linear or rotary actuators will be employed.
In certain embodiments of the invention, artificial vehicle windows, for example LCD HDTV, are used to produce scenes in space, on Mars or the Moon and re-entry to the Earth's atmosphere. The TV windows can be programmed to display any scenery.
The system is based on modifications of technologies and materials such as pressurized passenger cabins, tunnel boring machines, rail-based transportation, vacuum technology, hydraulic lifts, etc. This system is economically feasible and can be integrated into a transit system. Modern tunnels are built water tight. Similar technology and materials can be improved and used to build an air tight tunnel. Low pressure tunnels for vehicle speeds of 1 to 2 km/s have been proposed in the past. This system can be included in a passenger transit system. We have new vehicle, cabin, seating area and floating area designs for ride comfort. Automatic turning seats to alleviate deceleration force after recovery point. This system can be included in a passenger transit system.
One of skill in the art will appreciate that the system thus far described is adapted to provide a method and apparatus for accelerating a terrestrial vehicle in guided fashion and with a specific velocity profile. The result of the indicated acceleration includes an environment having a substantially controlled effective gravity characteristic therewithin over a particular time interval. In certain embodiments of the invention, this effective gravity characteristic includes a gravitational effect having a range between approximately normal Earth gravity and a microgravity of substantially zero. Passengers and technical payloads disposed within the vehicle consequently experience this substantially controlled gravitational effect.
For passengers, this gravitational effect can be perceived as exciting and entertaining. Technical payloads that can benefit from the indicated gravitational environment include apparatus adapted to perform scientific experiments and those adapted to perform manufacturing processes.
Scientific experiments that can benefit from a microgravity environment include, for example, experiments related to biomedical and pharmaceutical research, materials research including organic and inorganic crystallization research, organic polymerization research, fluid convection and combustion research including the convection of liquid and gaseous phases, and physical and chemical properties research including, for example, light pulse atom interferometry, investigations of surface tension and other properties of materials, metal refining and the purification of various materials, welding including electron beam welding, and the determination of diffusion coefficients in liquid and gaseous materials including for example metals, among others. In like fashion, manufacturing processes that involve these and other technical fields can benefit from the microgravity environment produced by a system of apparatus according to the invention. Such manufacturing processes include, without limitation, the preparation of crystalline materials, including organic and inorganic crystalline materials, as well as the preparation of amorphous materials, metallic materials and devices formed, in whole or in part, of such materials. Also included are a wide variety of processes including chemical reactions and/or phase transitions, as would be understood by one of skill in the art.
There exist important processes in the field of organic chemistry, materials science and semiconductor processing that have process time constants on the order of 30-60 seconds. The photocatalytic deposition of titanium oxide thin films is one such exemplary process.

- Atomic layer deposition (ALD) is a chemical gas phase thin-film deposition method where the precursor vapors are pulsed into the reactor alternately one at a time. During each precursor pulse, the gas reacts only with certain species and a (sub) monolayer of the desired material is formed. After each pulse excess precursors and bi-products are removed by purging with an inert gas. Under these conditions film growth is self-limiting. This unique growth mechanism gives accurate control of film thickness and composition and enables the deposition of conformal, high-quality thin films over large areas and on complex-shaped and porous substrates . . . . The duration of one ALD cycle depends strongly on the reaction kinetics . . . typically in research scale reactors a few seconds are required for the full ALD cycle but in optimized conditions cycle times as short as 1 s are possible.
- V. Pore, Atomic Layer Deposition and Photocatalytic Properties of Titanium Dioxide Thin Films, Laboratory of Inorganic Chemistry, Department Chemistry, Faculty of Science University of Helsinki, Finland, 2010, pp 12-13 (incorporated by reference herewith in its entirety).

Consequently, significant benefits may be realized in processes such as these, where significant time constants are on the same order as the time afforded for microgravity processing by the instant invention. For example, a system according to the present invention offers the opportunity to produce ALD crystal growth in microgravity conditions on terrestrial apparatus.
A recently published paper indicates the successful testing of cold atom light pulse interferometry in aircraft parabolic flights. Such testing “offers an unprecedented platform for development of future fundamental physics instruments to test general relativity of gravitation. Unlike orbital platforms, development cycles on ground-based facilities (either in a plane or in a drop tower) can be short enough to offer rapid technological evolution for the future sensors.” Light-Pulse Atom Interferometry in Microgravity, Stern et al., Eur. Phys.J. D 53, 353-357 (2009); DOI:10.1140/epjd/e2009-00150-5 (incorporated by reference herewith in its entirety). Notwithstanding the recognition that terrestrial development is advantageous, the above-cited reference limits its terrestrial activities to shot-tower experiments.
Medical intubations have been previously conducted in airborne microgravity experiments and similar experiments might benefit from the proposed terrestrial microgravity environment and apparatus. The above-noted and other processes and experiments known to benefit from, or otherwise be relevant to, microgravity environments include the growth of protein crystals, various aspects of semiconductor wafer growth, micro encapsulation processes, fused deposition manufacturing, and light pulse atom interferometry. Any or all of these processes, among many others, will benefit from the availability of a terrestrial low gravity environment as herewith proposed.
While the invention has been described in detail in connection with the presently preferred embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, it can be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims

1. A gravity moderation apparatus comprising:

a terrestrial vehicle, said terrestrial vehicle being adapted to support a payload; and

a vehicle guide, said vehicle guide being adapted to guide said terrestrial vehicle along a defined pathway so as to produce a substantially moderated gravity condition therewithin, said vehicle guide being supported by a beneficially configured macroscopic terrain feature between a first injection point and a second recovery point.

2. A gravity moderation apparatus as defined in claim 1 wherein said beneficially configured macroscopic terrain feature comprises a generally parabolic terrain feature.

3. A gravity moderation apparatus as defined in claim 1 wherein said terrestrial vehicle further comprises an internal surface region, said internal surface region defining a cavity within said terrestrial vehicle, said cavity being adapted to receive said payload therewithin.

4. A gravity moderation apparatus as defined in claim 1, further comprising a leveling mechanism, said leveling mechanism being adapted to substantially maintain said payload in a particular orientation with respect to a ground plane below said terrestrial vehicle during a particular time interval.

5. A gravity moderation apparatus as defined in claim 1 wherein said payload is adapted to produce a process result related to said moderated gravity condition.

6. A gravity moderation apparatus as defined in claim 5 wherein said process result comprises a result related to a light pulse atom interferometry process.

7. A gravity moderation apparatus as defined in claim 5 wherein said process result comprises a result related to a fluid convection process.

8. A gravity moderation apparatus as defined in claim 5 wherein said process result comprises a result related to a material crystallization process.

9. A gravity moderation apparatus as defined in claim 5 wherein said process result comprises a result related to a phase transition heat transfer process.

10. A gravity moderation apparatus as defined in claim 1 wherein said payload is adapted to produce a material having a characteristic related to said moderated gravity condition.

11. A gravity moderation apparatus as defined in claim 10 wherein said material comprises a crystalline material.

12. A gravity moderation apparatus as defined in claim 10 wherein said material comprises a metallic material.

13. A gravity moderation apparatus as defined in claim 10 wherein said material comprises a polymeric material.

14. A gravity moderation apparatus as defined in claim 1 wherein said payload includes human operating personnel.

15. A gravity moderation apparatus as defined in claim 1 wherein said payload includes a human occupant and said moderated gravity condition includes an entertainment experience.

16. A gravity moderation apparatus as defined in claim 1 wherein a vertically projected distance between said injection point and said recovery point is at least about 3 km.

17. A gravity moderation apparatus as defined in claim 1 wherein a vertically projected distance between said injection point and said recovery point is at least about 10 km.

18. A method of providing a moderated gravity environment comprising:

identifying a beneficial macroscopic terrain feature;

deploying a vehicle guide across said macroscopic terrain feature;

supporting a payload with a terrestrial vehicle;

operating said terrestrial vehicle along said vehicle guide so as to subject said payload to said moderated gravity environment.

19. A method of providing a moderated gravity environment as defined in claim 18 wherein said operating said terrestrial vehicle along said vehicle guide so as to subject said payload to said moderated gravity environment comprises subjecting said payload to a substantially zero gravity environment.

20. A method of providing a moderated gravity environment as defined in claim 18 wherein said operating said terrestrial vehicle further comprises controlling said terrestrial vehicle with a computerized control device according to a predetermined velocity profile.

21. A method of providing a moderated gravity environment as defined in claim 18 wherein said operating said terrestrial vehicle along said vehicle guide comprises diverting a high-speed rail vehicle from a regular intercity route onto a secondary route, said secondary route including said vehicle guide.

22. A method of providing an environment having a moderated gravity characteristic comprising:

diverting a high-speed rail vehicle from a regular intercity route onto a secondary route, said secondary route including a guide structure, said guide structure traversing a substantially parabolic terrain region, said guide structure defining a substantially parabolic pathway; and

operating said high-speed rail vehicle according to a preferred velocity profile across said substantially parabolic pathway so as to convey said vehicle substantially along a space-time geodesic.

23. A method of providing an environment having a moderated gravity characteristic as defined in claim 22 wherein conveying said vehicle along said space-time geodesic comprises operating said vehicle to provide an inertial environment within a payload coupled to said high-speed rail vehicle.