U.S. patent application number 10/249753 was filed with the patent office on 2004-11-11 for personal transportation system.
Invention is credited to Wu, Hengning.
Application Number | 20040225421 10/249753 |
Document ID | / |
Family ID | 33415542 |
Filed Date | 2004-11-11 |
United States Patent
Application |
20040225421 |
Kind Code |
A1 |
Wu, Hengning |
November 11, 2004 |
PERSONAL TRANSPORTATION SYSTEM
Abstract
An automated personal transportation system for moving
passengers and light freights comprising a track network and small
vehicles on the track network. There are a number of stations and
stops for loading and unloading on side tracks off the mainline of
the track network. The vehicle width is limited to a dimension for
one seat. The vehicles can be coupled statically or dynamically to
form a train. The track has side rails for the rigid wheels of the
vehicle and a central rail for centering the vehicle on the
guideway and providing additional acceleration and braking
capability. The control system for the movement of vehicles is
divided into three levels: the central control system, the wayside
control system and the vehicle control system.
Inventors: |
Wu, Hengning; (Reston,
VA) |
Correspondence
Address: |
HENGNING WU
11627 NORTH SHORE DR. 2B
RESTON
VA
20190
US
|
Family ID: |
33415542 |
Appl. No.: |
10/249753 |
Filed: |
May 5, 2003 |
Current U.S.
Class: |
701/19 ;
701/23 |
Current CPC
Class: |
G08G 1/20 20130101; B61L
27/04 20130101; B62D 1/265 20130101 |
Class at
Publication: |
701/019 ;
701/023 |
International
Class: |
G06F 017/00 |
Claims
1. A transportation system for moving passengers and freight,
comprising: a track network, said track comprising a pair of side
rails and a central rail; a plurality of vehicles, each said
vehicle having a body with a width for one passenger seat, a
plurality of rigid wheels engaged on said side rails for supporting
and moving the vehicle, a plurality of guiding wheels engaged on
said central rail for centering the vehicle on the track, an
identification means for providing vehicle identification
information, a distance sensor for measuring distance and speed of
an object in front of the vehicle, a wireless communication means,
driving and braking means for said rigid wheels, and a vehicle
control system connected with said distance sensor and said driving
and braking means for controlling the driving and braking of the
vehicle; a plurality of stops and stations on the side tracks off
the main lines of said track network for loading and unloading,
each stop and each station having an access notification device; a
plurality of wayside control systems, each having a computer
system, a means for detecting said vehicle identification
information of said identification means of the vehicle, and a
means for controlling switches on said track network; a central
control system having a computer system for user registration,
vehicle registration, and controlling the traffic flow; a
communication network connecting said central control system, said
wayside control system, said vehicle control system, and said
access notification system; whereby a passenger can enter said
vehicle at a station or stop and move directly from origin to
destination.
2. The transportation system according to claim 1, wherein said
vehicle further comprises a coupling means for mechanically and
electrically coupling the vehicles to form a train, said coupling
means being adapted for movement between a coupled position and an
uncoupled position in response to a signal from said vehicle
control system; whereby said central control system gives
instruction to said vehicle control system for performing static
and dynamic coupling of the vehicles; whereby the capacity of said
transportation system is increased by entraining.
3. The transportation system according to claim 2, wherein said
coupling means further comprises a sensor means for measuring the
force between said coupled vehicles and sending said force
information to said vehicle control system to adjust the driving
means.
4. The transportation system of claim 1, wherein said vehicle
further comprises an input panel for inputting destination
information; whereby said passenger can change his destination
during a trip.
5. The transportation system of claim 1, further comprising a
plurality of automatic parking facilities, each having a plurality
of carriers for moving said vehicles to a parking position, and
retracting said vehicles from a parking position.
6. The transportation system of claim 1, further comprising a
plurality of trailers, each said trailer having a body with a width
for one passenger seat, a plurality of rigid wheels engaged on said
side rails for supporting the vehicle, a plurality of guiding
wheels engaged on said vertical surfaces of said central rail for
centering the vehicle on the track, an identification means for
providing vehicle identification information, and a coupling means
for mechanically and electrically coupling said trailer to a said
vehicle.
7. The transportation system of claim 1, further comprising a
plurality of access devices, each access device having a memory for
the user account information, a LCD display for said vehicle
identification number, an open button, an close button, and a
wireless communication means for communicating with the vehicle
control system and the access notification device; whereby a said
user can use said access device to communicate with said access
notification device and operate said vehicle.
8. A transportation system for moving passengers and freight,
comprising: a track network, said track comprising a pair of side
rails and a central rail; a plurality of vehicles, each said
vehicle having a body with a width for one passenger seat, a
plurality of rigid wheels engaged on said side rails for supporting
and moving the vehicle, a plurality of guiding wheels engaged on
said central rail for centering the vehicle on the track.
9. (Cancelled):
10. A method of controlling movement of a vehicle through a track
network having a plurality of merging points, diverging points,
stations and stops, from an origin to a destination, comprising
assigning a vehicle identification number to said vehicle;
providing means for storing said vehicle identification number in
said vehicle; providing a distance sensor means to said vehicle for
avoiding collisions; setting up a plurality of control points, each
before said merging point, diverging point, station and stop;
dividing said track network into a plurality of segments between
said control points; providing a wayside control system at each
said control point, each said wayside control system has a means
for detecting said vehicle identification number and a means for
switch operation; providing a vehicle control system to said
vehicle for controlling the operation of said vehicle, said vehicle
control system operatively connected to said distance sensor means;
providing a communication network for connecting said central
control system with a plurality of said wayside control system and
said vehicle control system; planning the direction and speed
profile of said vehicles before said control points by said central
control system; informing the direction of said vehicle to said
wayside control system and informing the speed profile information
to said vehicle control system through said communication network;
detecting said vehicle identification number of said vehicle by
said wayside control system; implementing said direction of said
vehicle by said wayside control system; implementing said speed
profile for said segment of said track network and avoiding
collision according to information from said distance sensor means
by said vehicle control system; whereby the infrastructure cost of
said track network and the communication demand in said
communication network are reduced.
11. The transportation system of claim 1, further comprising an
additional driving and braking means, an actuating mechanism being
adapted for movement of said additional driving and braking means
between an unengaged position and an engaged position for extra
acceleration and braking capability in response to a signal from
said vehicle control system.
Description
BACKGROUND OF INVENTION
[0001] The present invention relates to a personal transportation
system. In particular, it relates to an automatic transportation
system for people and light freight.
[0002] Transportation plays an important role in civilization.
Nowadays, many cities around the world are facing serious
transportation problems, in particular, traffic gridlock and air
pollution from automobile use. There are many studies on the
traffic problems and potential solutions, for example, Stuck In
Traffic: Coping With Peak-hour Traffic Congestion by Anthony Downs,
The Brookings Institution, 1992, and Breaking Gridlock by Jim
Motavalli, Sierra club books, 2001. A salient feature of today's
city traffic is that travel origins and destinations have become
increasingly dispersed, varied and distant. Accordingly, automobile
becomes the dominant form of transportation due to its convenience.
In the United States, automobile accounts for 90% of passenger
transportation and 90% of people drive alone. The heavy dependence
on automobile also leads to traffic gridlock, air pollution,
traffic accidents, and the dependence on fossil energy. Although
there are progress in fuel efficiency, efforts to increase the
highway capacity seem to be ldifficult. In areas experiencing
traffic congestion, it is very expensive to construct new highways
and purchase the rights-of-way. The National Automated Highway
System or Intelligent transportation systems in the United States
attempts to increase highway capacity by embedding sensors on the
roadway and automated control of vehicles in short following
distances on dedicated lanes. However, considerable infrastructure
cost and liability issues pose serious doubts on this approach
(Transportation Research Board Special Report 253, National Academy
of Sciences, 1998). In addition, automobile is not readily
accessible to school children and the elderly, a large fraction of
the population. On the other hand, existing public mass
transportation systems such as subway, monorail, light rail and bus
systems are less favored than automobile in terms of convenience
and comfort. They are more suitable for intercity traffic and group
activities. As urban and suburban traffic becomes more dispersed,
it is difficult to maintain the high volume necessary to justify
the high construction and operation cost. The frequent stops of the
vehicles and the transfers needed for many destinations make trips
lengthy and uncomfortable, even for cities with well-developed
public transportation systems.
[0003] The limitations of existing transportation systems and the
need for new ideas have long been recognized. In 1968, US
Department of Housing and Urban Development published a report
Tomorrow's Transportation: New Systems for the Urban Future. One
concept to provide accessibility and service to the profusion of
origins and destinations in metropolitan areas is "personal rapid
transit", automated small personal vehicles on a network of
exclusive guideways. It is originally proposed as a public transit
system for areas of medium to low population density. The origin of
the concept can even trace back to inventors as early as 1953 (See
J. E. Anderson, Some Lessons From the History of Personal Rapid
Transit, 1996). A demonstration project at Morgantown, West
Virginia was funded, completed, and has been in continuous
operation since 1975. Except for the vehicle size larger than
current definition, the project demonstrated the basic features of
a personal rapid transit system: 1) Fully automated vehicles
capable of operation without human drivers. 2) Exclusive guideway.
3) Small vehicles. 4) Small guideways that can be located above
ground, at ground level or underground. 5) Vehicles able to use all
guideways and stations on a fully coupled network. 6) Direct origin
to destination service, without a necessity to transfer or stop at
intervening stations. 7) Service available on demand rather than on
fixed schedules. Activities in other countries include Cabtrack in
the United Kingdom, CVS in Japan, Cabinentaxi in Germany, Aramis in
France. There are some recent systems, such as Taxi 2000 and its
modification PRT 2000, and SkyTran in the United States, ULTRA in
the United Kingdom, and RUF in Denmark.
[0004] The personal rapid transit concept offers some desirable
features, but these systems have not been accepted for widespread
implementation. Critical questions have been raised about the
economical feasibility of the concept. See, for example, V. R.
Vuchic, Personal Rapid Transit: An Unrealistic System, Urban
Transport International (Paris), No 7, 1996, page 35. It seems to
be mutually incompatible between the small size vehicles for low
density travel and the substantial infrastructure investment for
guideways, stations and sophisticated automation justifiable only
for heavy traffic volumes. This is a reasonable argument in
consideration of the costs of existing guideway systems such as
subway, rail and monorail, and some previous personal rapid transit
systems suffered from the dilemma. Attempts to increase the
capacity by short headways of less than one second may face safety
concerns similar to those of the automated highway system.
[0005] The criteria for the practical feasibility of a new
transportation system may include: 1) Convenience and comfort. 2)
Appropriate capacity. 3) Cost-effective. 4) Fuel efficiency,
additional emphasis due to energy shortage. 5)
Environment-friendly, air pollution, noise, aesthetic structure. 6)
Safety, accident, theft, disease, weather. The traffic problems in
urban and suburban areas cannot be adequately addressed by addition
and improvement of existing transportation systems alone. New
transportation systems are needed, and the new systems must
demonstrate their feasibility against the above criteria.
SUMMARY OF INVENTION
[0006] Therefore, it is an object of the present invention to
provide an automated personal transportation system for moving
passengers and light cargo. This new mode of surface
transportation, termed "autoway", is complemental to existing
surface transportation modes of highway and railway. It can provide
the advantages of personal transportation to a large number of
people whose access to personal transportation (automobile) is
previously limited. For example, school children are too young to
drive a car, some senior citizens may be no longer able to drive a
car but are otherwise socially active, and still other people are
uncomfortable with the anxiety of driving. For autoway, the only
thing a driver needs to know is the destination. Both private and
public transportation can be operated on autoway. As for light
cargo transportation, autoway can be an ideal delivery system in
connection with electronic commerce for small items with dispersed
destinations.
[0007] It is another object of the present invention to provide
high speed and high volume transportation with competitive
infrastructure cost. Autoway can provide a cost-effective solution
to traffic congestions in many cities where it is very expensive to
build additional highway or subway. When a portion of the traffic
is moved to autoway, automobile users also get benefits of more
pleasant driving experience without traffic congestions.
[0008] Still another object of the present invention is to provide
a safe and environment-friendly transportation mode. A majority of
automobile accidents are caused by human errors. This is
essentially eliminated in the personal transportation system of
autoway. The energy consumption of vehicles on autoway will also be
significantly reduced. This will significantly reduce the air
pollution in cities.
[0009] According to one aspect of the invention, small size
vehicle, termed "autocar", is used on a railway-like track network.
The vehicle width is limited to a dimension for one seat. The
present invention maintains the advantages of both steel rail and
personal transportation like automobile. Steel rail is an
efficient, safe, and high speed transportation system. Modern
railroad vehicles can be easily switched in a short time of 0.6 s,
and a speed of about 300 km/hr can be achieved for high speed
trains such as Shinkansen in Japan and TGV in France. The
significant decreases in the vehicle size and weight open
possibilities unavailable to ordinary railroads. This leads to
small, light guideways and supporting structures. The guideways can
be pre-manufactured with a high precision and at a low cost. This
will significantly reduce the cost related to guideways and
stations and the noise level during operation.
[0010] According to another aspect of the invention, a central rail
is provided with a horizontal high-traction surface and vertical
surfaces for guiding wheels. While the rigid wheels on side rails
offer the advantages of low rolling drag and high speed reliability
of conventional rail, a wheel on the high-traction central rail can
be activated to provide acceleration and deceleration over 1
m/s.sup.2 when necessary. The guiding wheels can reduce noises
associated with lateral vibration of the vehicle.
[0011] According to another aspect of the invention, the vehicles
can be statically and dynamically coupled to form a train. Although
most people drive alone on highway, a significant number of
automobiles actually share the same direction at least for some
segments of the trip. Since the destinations of vehicles are known
to the system of autoway at the beginning, some vehicles can be
properly coupled to form a train. Therefore, high traffic capacity
can be achieved at a conservative headway.
[0012] According to another aspect of the invention, the control
system of autoway is divided into three levels: central control
system, wayside control-point control system, and vehicle control
system. The central control system is responsible for functions
related to the whole autoway system, such as vehicle registration,
user registration, and traffic control. The wayside control system
is related to the operations of stations and stops, diverging, and
merging. The vehicle control system is related to the operations at
the vehicle level, such as speed, braking, coupling and decoupling
procedures, and collision avoidance. The communication requirements
will be less demanding than a completely centralized system. The
automation infrastructure will cost less than the fixed block and
moving block control methods normally used in railway. The system
will be more error-tolerant. Since part of the control system cost
scales up with the capacity, the system can be also economically
viable for relatively low traffic density.
BRIEF DESCRIPTION OF DRAWINGS
[0013] FIG. 1 shows the components of the personal transportation
system.
[0014] FIG. 2 shows the communication relationship in the personal
transportation system.
[0015] FIG. 3 illustrates the relationship of the vehicle and the
track.
[0016] FIGS. 4A and 4B show the structure of the coupling
components.
[0017] FIGS. 5A and 5B show diverging and merging tracks
respectively.
[0018] FIGS. 6A-6D show arrangements of stops and stations of
autoway.
[0019] FIGS. 7A and 7B show parking facilities with random access
and sequential access respectively.
[0020] FIG. 8 shows a semi-underground construction of the
track.
[0021] FIG. 9 shows an arrangement of 4 tracks.
[0022] FIG. 10 shows an overhead construction of the autoway with 4
tracks.
[0023] FIG. 11 illustrates the relationship between the capacity
and the number of entrained vehicles in a single lane.
DETAILED DESCRIPTION
[0024] FIG. 1 shows an autocar 20 and a trailer 22 on a section of
the track network 24 of autoway. The track 24 has two side rails 70
for rigid wheels 62 of the autocar 20 and a central rail 72 for
additional acceleration and deceleration. The track 24 is
preferably pre-manufactured in factory with high precisions and
supported on an open frame structure 80. The track network connects
a number of stops and stations (not shown) for people to get on and
get off an autocar. The difference between a stop and a station is
that a station normally have empty autocars available immediately
for service but a autocar will be dispatched to a stop upon
request. In practice, many other services and amenities will also
be available at stations, such as maintenance, restaurants, shops,
and restrooms. The access notification device 26 installed at stops
and stations informs the autoway system the demand for service. The
wayside control-point control system 28 is used for the operation
of switching actions at diverging, merging, and stops and stations.
The access notification device 26 and the wayside control system 28
are connected to the central control system 30 by a communication
network 36, preferably a wired communication network 34 such as
copper wire or optical fiber. The communication to the autocars is
provided by wireless communication means 32, and preferably a
cellular structure is used to cover the track network.
[0025] The autocar 20 has its vehicle identification that can be
read by a scanning device. In a preferred embodiment, an
identification plate with printed vehicle identification number and
corresponding bar code 48 is provided at the door. The printed
identification number is for the human eyes and the bar code 48 is
for the optical scanning device 96 at the wayside control system
28. For redundancy as a safety consideration, a smart card 50 with
the identification information can also be installed in the vehicle
and the identification information can be read by a smart card
reader 98 at the wayside control system 28. The autocar has a
distance sensor device 52 for the measurement of the distance and
speed of an object in front of the vehicle. This can be a laser
device, a radar device, or an ultrasonic device. The distance and
speed data are fed to the vehicle control system 42, or a computer
in the vehicle, for collision avoidance and dynamically coupling of
vehicles to form a train. The couplers (front coupler 54 at vehicle
front and rear coupler 56 at vehicle back) are used to connect two
vehicles mechanically and electrically. An additional communication
device 58 is provided for inter-vehicle communication. This is a
point-to-point short distance communication device, such as an
infrared transceiver or a high frequency radio device like
blue-tooth device. The vehicle 20 communicates with the wayside
control system 28 and the central control system 30 through a
wireless means by the antenna 60.
[0026] An important feature of the autoway is the small size of the
autocar 20 The width of the autocar body 46 should be as small as
possible so that weight is distributed longitudinally to reduce the
size of the guideway. The smallest width is for one seat. As the
dimension for a comfortably seated person is 66 cm by 82 cm, the
width of the autocar can be chosen as about 85 cm. A typical
vehicle size for one seat can be 85 cm in width, 140 cm in height,
and 200 cm in length. The track gauge, or the distance between the
central lines of the side rails, can be about 80 cm. For
conventional railroad, the vehicle width is much greater than the
rail gauge. Because the small size and light weight of the autocar,
the relative magnitude of the side force due to wind can be
significant. To increase the stability of the autocar, the track
gauge is increased to a maximum value appropriate for the vehicle
width. Since the average occupancy of automobile is 1.1 person in
the United States, the choice of one seat per vehicle is
reasonable. The personal nature of autocar provides people with
comfort and privacy. Audio, video, and climate control can also be
adjusted at individual's choice. For people traveling in a group,
the autocars can be statically coupled to move together. A trailer
22 is also provided for more travel options. A trailer 22 is
similar to an autocar 20 but does not have its own power and
driving system. It is always statically connected to an autocar to
either add cargo volume or provide additional seats. A trailer with
a typical size of autocar can provide two seats or a cargo space of
about 1.2 m.sup.3. For example, a mother and a very small child can
choose to travel together in a trailer with the front autocar
empty.
[0027] Other components of autocar are not shown but are obvious to
those skilled in the art for the proper operation of the vehicle.
The autocar must have a power source like an engine, or fuel cell,
or battery, or electricity provided by a collection shoe from a
power line. The autocar must have the necessary driving and braking
means. In a preferred embodiment, the autocar 20 has a small
battery but get its power mainly from the power line 82 by an
electricity collection shoe. The battery will provide power to
drive the autocar to a nearby station when there is a power
outrage, and to provide power to go through areas without power
line such as stops, stations and parking facilities where power
line may be terminated due to safety considerations. The battery
can be rated for the driving distance, and a capacity of 4 km will
be sufficient for most urban areas. The autocar also has a driving
and braking system. Electric motors are used to drive the wheels
and regenerating brakes are preferred for normal operations.
[0028] The communication relationship of the components of the
personal transportation system is illustrated in FIG. 2. The
central control system 30, the wayside control system 28, the
access notification device 26, and the autocar 20 are connected by
a communication network 36. Each autocar 20 is registered with the
central control system 30 for a unique vehicle identification
number. For example, a combination of 5 digits and capital letters
can be used for vehicle identification number. With the exclusion
of easily confused letters of I and O, this combination can handle
more than 24 million vehicles. Each stop or station is also
assigned an identification number. The station (stop)
identification can use a five-digit plus two-digit system. The five
digits can have a maximum number of stations and stops of 100,000.
The two optional digits can identify more detailed station
locations within a general destination. For example, station
identification number 12345 is given to airport x, with default
station as 12345-00 and 12345-00 can be for general entrance,
12345-01 for terminal 1, 12345-02 for terminal 2, and so on. A list
of station and stop identifications can be provided in a booklet,
or a map, or the computer in the vehicle. Voice input of station
identification can also be provided. Although existing station
ticket systems can be adapted for use in the present invention, a
preferred method is issuance of an access device 38 for each user
account. The access device 38 has an "open" button 106, a "close
button" 107, a LCD display 104 for vehicle identification number,
and a wireless communication means 102 such as infrared or radio
transceiver for communication with the corresponding to
transceivers of the access notification system and the autocar. The
access device 38 has a memory for storage of the user account
number.
[0029] The vehicles on autoway can be private-owned or
public-owned. For public-owned vehicles, the user 40 can have
exclusive use like a rental car or shared use like -a bus. When an
user 40 push the "open" button 106 of the access device 38 in front
of the access notification system 26 with its wireless transceiver
94, the access device 38 provides a signal of the user account
number. The default option for an account with a private car is to
use his private car. Generally, the user 40 can choose an exclusive
use or shared use from the access notification system 26 for a
public vehicle. The user can also make other choices such as
trailer and statically coupled vehicles in a group, using the
function buttons 92 and the display 90 of the access notification
system 26. For people in a group of statically coupled vehicles,
each user in the group will then check in with the access
notification system. The central control system 3 will assign a
vehicle to serve the station. Then the vehicle identification
number will be sent to the access device 38 and shown on the LCD
display 104. The user 40 then proceed to find the autocar 20 with
the identification number shown on the LCD display 104, and open
the door of the autocar with the access device 38. The autocar 20
further verifies the user account information and the door is
opened. The user 40 can then input the destination identification
number from a communication panel 44 in the autocar 20. The
communication panel 44 has a LCD display 110, keypads 112 for
input, and function keys 114. When the user pushes the "car" key,
he is able to input the destination identification number. When he
pushes the "phone" key, he is able to make a phone call. The LCD
display 110 on the panel 44 will show information such as the
destination, the current location and the time remaining for the
trip. The system will get the user to the destination without any
stops or transfers at other stations. At the destination, the user
40 can use the "close" button 108 to lock the vehicle or the system
will automatically lock the vehicle after a predetermined time or
before moving. A user 40 can also change his destination using the
communication panel 44 during the trip.
[0030] The operation of the vehicle 20 on the track 24 is further
illustrated in FIG. 3. The side rails 70 and the central rail 72
are connected by cross bars 78 to form a track 24 The flanged rigid
wheels 62 run on the side rails 70 with a low friction surface,
like a conventional railway system. Preferably the wheels 62 and
the side rails 70 are made of steel. The side rails 70 offer the
advantages of low rolling drag and reliable high speed operation.
Therefore, it is possible to have a speed about 50 km/hr in local
areas, a speed of about 100 km/hr on major routes, and even higher
speed for certain long distance routes. Pneumatic rubber tires are
not used because of their unpredictable failure mode. However, it
is known that steel wheel on rail has very low wheel adhesion and
it is difficult to maintain consistent acceleration and
deceleration over about 1 m/s.sup.2. Therefore, an additional
central rail 72 is provided with a substantially horizontal surface
74 of high traction and substantially vertical surfaces 76 of low
friction for guiding wheels. The vertical surfaces 76 are symmetric
to the central vertical plane of the track 24, and the guiding
wheels 84 will center the vehicle 20 on the track 24. Slight
curvature may be introduced for the surfaces of the central rail,
or other shapes may be used for the same functions. For example,
the horizontal surface 74 may have a small convex curvature to
avoid accumulation of water. The high friction surface can be
accomplished by a rough surface with patterns, or a polymer layer
on the metal similar to a deck surface for an aircraft carrier. The
low friction surface can be obtained by polishing, lubrication, and
special coatings like teflon. A rubber tire 87 with a high traction
surface 89 can be pushed by a mechanical or hydraulic means 86 onto
the horizontal surface 74. This additional tire can be actuated by
the vehicle control system to provide acceleration and deceleration
over 1 m/s.sup.2 when necessary or when slippery is detected from
the loss of power on the rigid wheels 62. The force on the tire can
be adjusted and can even be increased beyond the weight supported
by the back wheels since a rail gripping condition can be created
by the tire 87 and the lower wheels 88. This is useful for
emergency braking, and the traction force is not limited by the
weight of the vehicle. The vertical guiding wheels 84 mounted on
the chassis of the vehicle reduce the noise related to the lateral
vibration of the vehicle 20. At places where the central rail 72
starts or ends, the two vertical surfaces 76 gradually converge to
facilitate the engagement of the guiding wheels 84. The central
rail 72 is terminated at parking facilities for easy automatic
parking operation. The central rail 72 also adds structural
integrity to the track and prevents derailing of the vehicles. It
should be noted that linear induction motors are often recommended
for use in personal rapid transit systems in the literature. The
advantage of the linear induction motors is more accurate control
of vehicles for short headways. However, linear induction motors
have the disadvantages of more expensive guideways and vehicles and
lower energy efficiency than electric motors. Therefore, linear
induction motors are justifiable only for a very heavy traffic
volume.
[0031] The coupling components of autocar consists of a rear
coupler 56 (FIG. 4A) and a front coupler 54 ( FIG. 4B). They are
installed on the vehicle body 46 through holes 126 and 144 provided
in the components. At least one of the couplers should be installed
on a suspension with some freedom for movement to accommodate the
misalignment of the vehicles during motion. The rear coupler 56 has
a pair of keys 122 that are pushed toward the center line by
springs 120 attached to them respectively. Once the instruction of
coupling is given by the central control system 30, the vehicle
control system 42 can get the distance and speed between the two
vehicles from the distance sensor device 52, and then the following
vehicle can be controlled to approach the leading vehicle slowly.
The cylinder 130 of the front coupler 54 can push through the keys
122 until the keys 122 get into the opening 132 in the cylinder
130. The electrical contacts 134 in the cylinder 130 get in touch
with corresponding contacts 124 in the rear coupler 56, and
electrical connection is established between the two vehicles. To
uncouple the vehicles, a motorized device 136 with proper
electrical connections 138 can follow the instruction from the
vehicle control system 42 and turn the cylinder 130 by 90 degrees.
This can be done either electronically by control of the motor
rotation or mechanically by a gear structure with teeth on a
quarter of the cylinder circumference. A force sensor 140, for
example, a strain sensor, is used to measure the force between the
two vehicles. Although the vehicles are set to the same speed when
coupled, difference in speed controls will lead to a force of
tension or compression. The signal from the force sensor 140 is
provided to the vehicle control system 42 by proper electrical
connection 142, and the signal is used to adjust the speed so that
the force is below a certain noise level.
[0032] The vehicles can be statically coupled or dynamically
coupled. Static coupling is initiated by the user for people
traveling in a group or for adding cargo and passenger space.
Static coupling is accomplished before the vehicles leaving a
station. A trailer is always coupled with an autocar, and the
coupling can be accomplished by backing the autocar towards a
trailer. Voice communication can be easily provided to vehicles in
a statically coupled group. Dynamical coupling and decoupling are
initiated by the central control system to improve the capacity of
autoway. Vehicles that share some segments in their traveling
routes are coupled together to form a train. The inter-vehicle
communication in a train enables the vehicles to brake
simultaneously during emergency. Coupled vehicles are much safer
since malfunctioned vehicles can be pulled by the train.
[0033] There are two types of switches in the track network:
diverging 152 (FIG. 5A) and merging 158 (FIG. 5B). For diverging
152, the mainline 150 is divided into a tangent side 154 and a
turnout side 156. For merging 158, a turnout side track 156 is
merged with the mainline 150. The arrows indicate the directions of
traffic flow. When the wayside control system 28 detects the
identification of the approaching vehicle 20, the appropriate
switch position at 152 and 158 will be set and verified according
to the traffic flow instruction from the central control system 30.
The speed instruction is also given to the vehicle 20 for this
segment of the track. The central control system 30 will plan the
traffic flow so that collision will not happen, and the wayside
control system 28 will detect the vehicle movement and operate the
switch accordingly to avoid two vehicles running into a merging
track at the same time. In case of violation, a stop instruction
will be given to the vehicle immediately. Further, the distance
sensor 52 of the vehicle 20 offers the safety of collision
avoidance at the vehicle level. Since there are only a limited
number of switch points, railroad switch can be a reasonable
choice. Railroad switch is a reliable technology with a short
switch time of 0.6 s for modern switches. For even shorter
headways, wayside actuated vehicle switch can also be
considered.
[0034] The stops and stations can have many variations. The
simplest form of station 25 is just a side track 164 off the
mainline 150 (FIG. 6A). The station 25 on the side track 164 is
divided into an unloading area 160 and a loading area 162, each
having a length for a number of vehicles appropriate for the
traffic condition. At a station 25, there are empty vehicles on the
track. At a stop 27, empty vehicles will move to a station or a
parking facility immediately. Normally, a vehicle is immediately
available at a station, and a user may wait for a short time, say
less than 1 minute, for his vehicle at a stop. An approximate
guideline is to have a stop for every major building and a station
every 1000 m in urban areas. The arrangement of stops and stations
on autoway is similar to the parking facilities of a personal
transportation system like automobiles but quite different from
mass transit systems. For a personal transportation system, the
stations are close to business or residential buildings, and there
are no stations on a major traffic route. For a mass transit
system, the stations are located along the traffic route. In FIG.
6B, a stop 27 with a parking track 166 and a parking facility 168
is shown. This is a likely arrangement for a stop 27 in front of an
office building. When there are many vehicles involved in a station
such as a connection point to a mass transit system like an airport
and a railway station, the well-known ladder tracks 170 can be used
(FIG. 6C). In FIG. 6D, a track 164 on the side street between two
mainlines 150 is used as a station.
[0035] The major difference in the parking facility of autoway to
conventional parking facility for automobiles is that all parking
are varlet parking by the autoway system. The autoway system will
automatically move the autocar to a nearest parking facility,
saving people the trouble to find a parking lot and then walk back
from the parking lot. The system keeps track of the locations of
all vehicles and transfer a particular vehicle to the location of
demand. This can be very convenient when the available parking lot
is far away or when people get into a large shopping mall from one
entrance and get out from another entrance. According to the types
of access mode, the parking facility can be of two types: the
random access type (FIG. 7A) and the sequential access type ( FIG.
7B). The random access parking is for private vehicles and
exclusive rental vehicles, and each vehicle can be accessed
independently. A carrier 172 residing on the parking track 166 can
move along a carrier track 174 perpendicular to the autocar track
166 to put the autocar 20 into a parking position. The sequential
access parking is for public shared vehicles. A carrier 172 at the
entrance 174 move the vehicle 20 to a specific parking track to
park sequentially. At the exit 176, a carrier 172 can move vehicles
20 out sequentially. This creates a first-in first-out sequential
access. If the entrance is also used as exit, a first-in last-out
sequence is created. Multilevel parking is possible and even more
efficient when the carrier can move vertically at the entrance and
exit point. In this case, multiple carriers can be used to move in
a vertically circular form to improve parking speed. Depending on
the parking arrangement, a parking lot can handle 6-12 times more
autocars than automobiles. Put it another way, a previous 8-story
parking lot for automobiles can become an office building with only
the basement for autocar parking.
[0036] The autoway track can be built above the ground, at the
ground level or underground. Preferably it can be built above the
ground or underground to save the expenses for right-of-ways. One
lane is normally used for street traffic, and two or four lances
are used for major traffic routes. FIG. 8 shows a semi-underground
construction appropriate for residential areas. The track 24 and
its supporting structure 80 are located inside a shallow concrete
passage 184 below the ground level and a concrete cover 180 with a
width of a sidewalk road is supported by metal bars 182. The tunnel
is open at the window level of the autocar 20 for people to see the
natural light. This structure costs less than a complete
underground construction, and can easily go underground for road
crossing. The stations are easily accessible. It does not obstruct
the views of automobile drivers on the road and residents in the
houses. Grass can be planted on the top concrete to further improve
the environment appeals.
[0037] FIG. 9 shows a 4-lane construction of autoway for a major
traffic route. A second level is constructed on the first level
with open frame supporting structures 186. Due to the small size of
autocars, the four-lane construction occupies less space than one
standard lane on the highway or space of one track on the railway.
It will be shown that its capacity for moving people is equivalent
to four 6-lane highways. This structure can be built either
underground or overhead at the median line of existing highway.
FIG. 10 shows a side view of an overhead construction of a 4-lane
autoway. Open frame structure 188 is built on small foundations 190
to support the tracks 24 of autoway. The light weight structure
offers more opportunities for aesthetic considerations. It is also
less susceptible to wind, rain, snow, and earthquake. As many
components can be pre-manufactured, a significant shorter
construction period and a lower construction cost are possible as
compared with other road construction.
[0038] The control system of autoway is divided into three levels:
central control system 30, wayside control-point control system 28,
and vehicle control system 42. The central control system is
responsible for functions related to the whole autoway system, such
as vehicle registration, user registration, and traffic control. At
any moment, the central control system knows the locations of all
parked vehicles, the destinations of all moving vehicles, and the
approximate locations of all moving vehicles within a known track
segment. The central control system also knows the working
conditions of all the tracks, stations, stops, and parking
facilities. With the knowledge of the locations of parked vehicles,
the central control system can dispatch a vehicle to the location
on demand. With the destination information, the central control
system can arrange dynamic coupling of vehicles. Preferably, a map
of the autoway is displayed on the monitor of the computer of the
central control system with all the vehicles simulated on the map.
Various traffic statistics are also displayed. Manual intervention
can be implemented when necessary. In practice, a series of
computers are used for reliability and scalability. In case of
failure of a computer, a backup computer will automatically take
over. More computers can be added in response to an increase in the
traffic volume.
[0039] The central control system plans the traffic flow of each
vehicle on a segment basis before a control point. The traffic flow
instruction includes the direction and the speed profile for the
next segment. A control point is like the traffic light on the
street. Control points are set up before diverging, merging, stops
and stations with enough distance for emergency braking. The
control points divide the autoway track network into segments. The
exact location of a vehicle is only known to the central control
system at a control point when the wayside control system detects
the identity of a moving vehicle. At this point, the wayside
control system operates the switch for the desired direction, and
the vehicle is informed of the location of the control point and
then follows the speed profile. The location information is
displayed to the user for psychological reasons just as the floor
number is normally shown on an elevator. The central control system
can use the speed profile to calculate the approximate location of
the vehicle for planning purpose. Delegating the implementation of
traffic flow to the wayside control system and the vehicle control
system is cost-effective in comparison with the high guideway cost
of the fixed block system and the demanding communication
requirements of the moving block system used in conventional
railways. In the fixed block scheme, the guideway is divided into
segments called blocks and apparatus is provided in each block to
detect the presence of a vehicle. The minimum separation between
vehicles is at least one block. When a short headway is desired,
the infrastructure cost becomes excessive. In the moving block
scheme, each vehicle transmits its location to the central control
system and receives instructions from the central control system on
a periodic basis. The headway is related to the communication rate.
When a short headway is desired, the communication load becomes
excessive. The control method in the present invention is feasible
due to the collision avoidance system of the vehicle and the
ability of the autocar to stop in a short distance like an
automobile.
[0040] The wayside control system 28 is a computer system related
to the operations of stations and stops, diverging, and merging.
The central control system informs the wayside control system
before each control point the sequence of arriving vehicles,
directions of travel, and the status of entraining. The wayside
control system then implements the direction control by turning the
proper switch position. The issue of merging involves two control
points, and the wayside control systems are connected and their
actions are set to be exclusive, that is, only one is open for
traffic at a time.
[0041] The vehicle control system 42 is a computer system related
to the operations at the vehicle level, such as access control,
speed, braking, coupling and decoupling procedures, and collision
avoidance. Before each control point, a speed profile is provided
to the vehicle control system from the central control system. The
speed profile is designed for the specific segment of the track. It
consists of a series of speed and distance instructions. For
example, an autocar from a turnout side at a merging point may get
a speed profile: 50 km/hr to 30 km/hr in a distance of 20 m, 30
km/hr for a distance of 30 m (the turning part), 30 km/hr to 100
km/hr in a distance of 35 m (the additional rubber tire will be
activated by the vehicle control system for the necessary
acceleration), and 100 km/hr for 500 m. In this case, the autocar
is assumed to take care of the transition of speed by a
predetermined procedure, but maintain the end results of time and
distance. Other forms of speed profiles may also be used. Since the
speed meter and distance meter of the vehicle are used, small
errors may occur but the errors are eliminated at each control
point. The actual physical implementation of the speed control can
use currently available technologies for automobiles and trains. As
the cost of the vehicle control system scales up with the capacity,
the system can be also economically viable for relatively low
traffic density.
[0042] The central control system assumes that the wayside control
system and the vehicle control system perform the functions as
instructed. Eventually some errors will happen. There are
redundancies to reduce the effect of malfunctions in devices. At
each level, procedures are established to catch potential errors
and correct the errors if possible, and then the errors are
reported to the central control system. A warning will be issued to
the central control system if an error cannot be fixed and
potentially dangerous. The central control system will respond
immediately to any warning messages. The central control system
will use the error messages to make maintenance and improve
operation procedures. At the vehicle level, the distance sensor
device will be used to avoid collision. Besides, the error reports
can be used for improvements in new versions of the control
software.
[0043] Although autoway is offered as a solution to urban traffic
congestion and air pollution, it can also be very useful in other
places. For example, autoway can be used on a company campus, a
university campus, and a military base, for internal
transportation. In a national park, autoway can provide a high
volume of traffic with minimum impacts on the environment due to
its small size and easy of construction. The autoway can also
provide some preliminary access control to certain parts of the
track network. In rural areas with many rivers or mountain areas
with a difficult terrain, it may be costly to build a highway but
an autoway can be built at a low cost. The automatic nature of the
autoway and the open frame structure of an overhead construction
make the autoway more reliable in bad conditions such as fog, rain,
wind, snow, flood, and falling rocks. The communication network of
the autoway can also provide rural and mountain areas with access
to broadband communication and help social and economical
developments in these areas.
[0044] As for light cargo transportation, autoway can be an ideal
delivery system in connection with electronic commerce for small
items with dispersed destinations. A sender can set the destination
and the receiver for the autocar, and the receiver can be notified
in advance the time of arrival, and then the designated receiver
can open the autocar with his access device. It can be set up to
transport goods between factories, users, warehouses, and stores
with specifically designated stations and the delivery can be
performed at light traffic periods.
[0045] Autoway provides a mode of surface transportation for both
private and public transportation with convenience and comfort. As
a form of public transportation, autoway retains all the features
of the concept of personal rapid transit. As a form of private
transportation, autocar is safer, more comfortable, and more
affordable than automobile. A person sitting comfortably in an
autocar can make phone calls, play DVD video, read a newspaper, or
browse the internet, at his own privacy. Since autocar goes
directly to the destinations without any stops and transfers,
considerable time will be saved for commuters. A tourist no longer
needs to worry about driving directions or transfers at stations.
As a public transportation, it is available 24 hours a day and 7
days a week and offers the convenience, comfort and privacy of a
personal transportation system. Driving an autocar is as easy as
using an elevator. The only thing a passenger needs to know is his
destination. This offers the advantages of personal transportation
to many people such as school children and senior citizens who
cannot use an automobile on their own.
[0046] Table 1 lists the operational capacities of existing urban
transportation systems and autoway. A conservative headway of 2
seconds is used for both automobile and autocar. It should be noted
that all the capacities can be increased significantly at the
expense of comfort and safety. For example, the average occupancy
of automobile is 1.1 and a capacity of 2200 vehicles/hr is possible
at a shorter headway. If a car can always operate at full occupancy
of 4 people, the capacity will be quadrupled. The capacity of bus
and subway can be easily doubled during rush hours with half of the
passengers standing. The headways of bus and subway can be
technically much shorter but are mainly limited by the feeding
mechanisms for stations. The capacity values of Table 1 are typical
numbers in some medium-density metropolitan areas in the United
States at comparable safety and comfort. As shown in FIG. 11, the
capacity of autoway increases with the number of entrained
vehicles. The minimum capacity of an autoway lane is equivalent to
a highway lane when there is no entraining. Although most people
drive alone on highway, a significant number of automobiles
actually share the same direction at least for some segments of the
trip. Dynamic coupling on autoway is like virtual car-pool. If the
traffic conditions in an area is known, the capacity of autoway can
be better estimated by computer simulation. A simple estimation is
given by analysis of the capacity of subway. The line capacity of
7,812 persons per hour is equivalent to 2.17 persons per second. It
takes only 3.6 seconds to have 8 people to share the same
direction. Therefore, the choice of 8 cars per train seems to be
reasonable. When the subway capacity is doubled during rush hours,
the capacity of autoway can also be doubled. In a sense, autoway
has certain elasticity in capacity to accommodate an increase in
the traffic flow. Roughly speaking, one lane of autoway is
equivalent to one subway line or one 6-lane highway. Since four
lanes of autoway can be accommodated in the space of one highway
lane, a 4-lane autoway may have a capacity of four subway lines or
four 6-lane highways.
1TABLE 1 Traffic capacity estimates (Speed = 100 km/hr) Capacity
Vehicle type (persons/hr) Ratio Remark Automobile 1,673 1 Single
occupant, headway = 2 s, car length = 4.2 m. Bus 798 0.5 40
occupants, headway = 180 s, bus length = 12 m. Automobile + 2,442
1.5 Same conditions as Bus bove. Subway 7,812 4.7 5-car train, 400
occupants, headway = 180 s, car length = 24 m. Autocar (1 lane)
11,180 6.7 8-car train, 8 occupants, 1 lane, headway = 2 s, car
length = 2 m. Autocar (4 44,720 26.7 8-car train, 8 occupants,
lanes) 4 lanes, headway = 2 s, car length = 2 m.
[0047] The cost of construction, operation and maintenance of
autoway will be significantly less than existing guideway systems.
The autocar will cost much less than an average automobile. The
small size of autocar results in light guideway structures.
Construction of the guideway is mostly an efficient assembly
process since the guideway can be pre-manufactured in a factory,
for example, as welded structures. The autoway stops and stations
are simple and small. Stops and stations can normally be
constructed to connect to the basement, ground floor, or second
floor of an existing building. This both adds convenience to the
users, and saves the costs of adding additional elevators. The
three-level control system reduces the cost of automation. In
addition, computers and communication devices are reliable and
widely available at low cost nowadays. Snow removal of the guideway
can be accomplished automatically by a specially designed
snow-removing vehicle. Since error reporting procedure s are used
in the control systems, maintenance can be easily performed by
replacing faulty modules. Only a small number of staff are needed
to operate and maintain the software and hardware of the autoway
system. Therefore, the advantages of personal transportation can be
provided at a competitive cost.
[0048] The fuel efficiency of autocar will be significantly higher
than automobile. The weight of an autocar will be less than 25% of
th weight of an average automobile. The front area of an autocar is
about 50% of an automobile. The low drag of steel rail will offer
an energy saving of about 25%. The high efficiency of the electric
motor and electricity generation will offer an energy saving of
about 50%. It is estimated the fuel consumption of the autocar is
about 5% of an average automobile. If we assume the gas mileage of
an average automobile is 10 km/liter (25 mile/gallon), the autocar
can achieve a gas mileage of about 200 km/liter (500 mile/gallon).
There may be some departure from the estimate, but the improvement
in fuel efficiency is significant.
[0049] The high fuel efficiency of autocar will significantly
reduce air pollution in urban areas. In rural areas, autoway can
reduce the environment problem of soil erosion related to highway
construction, and the overhead construction of autoway reduces
interference with wild life. The noise level of modern railway has
been significantly reduced due to high rail precision and
maintenance. The noise level of autocar will be even lower due to
the small weight and the lower speed. The light guideway will also
provide opportunities for aesthetic structures.
[0050] Autoway will be a safe and reliable transportation mode.
Since 90% of accidents on highway are caused by human errors,
autoway essentially eliminates this accident source. Redundancy and
error-checking in the system will make system-related accidents
rare. For example, vehicle identifications can be obtained from
both the bar code and the smart card. Both wired and wireless
inter-vehicle communications are provided. The network structure of
communication and track will ensure proper operations even if some
segments have failed. Procedures for collision avoidance are
implemented at all the three levels of control systems. Other
safety issues such as theft, robbery, and contagious diseases, are
also significantly reduced. Autoway is also less susceptible to
wind, rain, snow, fog, and earthquake. The central control system
can be linked to an earthquake warning system, and emergency
procedures can be initiated during an earthquake.
[0051] Other embodiments of the invention will be apparent to those
skilled in the art from a consideration of this specification or
practice of the invention disclosed herein. For example, the length
of autocar can be increased to have more than one seat in places
with a higher average occupancy. Special vehicles can be designed
for people with disabilities. A hook can be provided to pull the
autocar for steep grades. Noise barriers can be set up near the
sources of noises. Weight sensors can be installed at stations and
stops or on the track to avoid overloading. Surface modification of
the wheels and rails can be performed for better performance. Other
coupling devices can be used. For the central rail, the horizontal
surface can be physically in several sections but functionally as
one similar to some monorail designs, and the vertical surface can
be in the form of a bar or tubing. Other existing methods for
centering the vehicle and providing additional driving and braking
ability can also be adapted for the system. At seaside, the tracks
can be made of polymer-based composite materials instead of steel
to avoid corrosion. Data encryption and verification can be used
for communication security. It is intended that the specification
and examples shall be interpreted as illustrative and not in a
limiting sense, with the true scope and spirit of the invention
being indicated by the following claims
* * * * *