U.S. patent application number 11/342857 was filed with the patent office on 2006-09-21 for method and apparatus for automatic selection of alternative routing through congested areas using congestion prediction metrics.
Invention is credited to Joel Kickbusch, Joseph Wesley Philp, Mitchell Scott Wills.
Application Number | 20060212188 11/342857 |
Document ID | / |
Family ID | 38327859 |
Filed Date | 2006-09-21 |
United States Patent
Application |
20060212188 |
Kind Code |
A1 |
Kickbusch; Joel ; et
al. |
September 21, 2006 |
Method and apparatus for automatic selection of alternative routing
through congested areas using congestion prediction metrics
Abstract
A scheduling system and method for moving plural objects through
a multipath system described as a freight railway scheduling
system. The scheduling system utilizes a cost reactive resource
scheduler to minimize resource exception while at the same time
minimizing the global costs associated with the solution. The
achievable movement plan can be used to assist in the control of,
or to automatically control, the movement of trains through the
system. Alternative routes through congested areas are
automatically selected using congestion prediction metrics.
Inventors: |
Kickbusch; Joel; (Rockledge,
FL) ; Philp; Joseph Wesley; (Indialantic, FL)
; Wills; Mitchell Scott; (Melbourne, FL) |
Correspondence
Address: |
DUANE MORRIS LLP
Suite 700
1667 K Street, N.W.
Washington
DC
20006
US
|
Family ID: |
38327859 |
Appl. No.: |
11/342857 |
Filed: |
January 31, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10785059 |
Feb 25, 2004 |
|
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11342857 |
Jan 31, 2006 |
|
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60449849 |
Feb 27, 2003 |
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Current U.S.
Class: |
701/19 ;
701/532 |
Current CPC
Class: |
B61L 27/0011 20130101;
B61L 27/0027 20130101; G06Q 10/06 20130101 |
Class at
Publication: |
701/019 ;
701/200 |
International
Class: |
G01C 21/00 20060101
G01C021/00 |
Claims
1. A method of scheduling the movement of trains, each over a
selected route, by predicting the occurrence of congestion due to
the planned movement of the trains over a selected route
comprising: (a) identifying factors which contribute to congestion;
(b) assigning a metric for each factor; (c) evaluating the metrics
associated with a selected route; (d) if the evaluate metrics
exceed a predetermined threshold, scheduling one or more trains
scheduled for the selected route to alternate routes.
2. The method of claim 1 wherein the step of identifying includes
evaluating the historical performance of train movement over a
selected route.
3. The method of claim 1 wherein the factor is weighted as a
function of its relative contribution to congestion.
4. The method of claim 1 wherein the step of evaluating includes
cumulating the metrics for a selected route.
5. The method of claim 1 wherein the predetermined threshold is a
selected as a function of the historical occurrence of congestion
movement of trains over a selected route.
6. A method of scheduling the movement of trains, each over a
selected route, by predicting the occurrence of congestion due to
the planned movement of the trains over a selected route
comprising: (a) identifying factors which contribute to congestion;
(b) assigning a metric for each factor; (c) evaluating the metrics
associated with a first planned movement of plural trains over a
selected route; (d) evaluating the metric associated with a second
planned movement over a selected route; (e) selecting the planned
movement having the lowest metric for scheduling the movement of
trains over the selected route.
7. The method of claim 6 wherein the factors include at least one
of train density, environmental, temporal, seasonal, and track
topology.
8. The method of claim 1 where the step of scheduling one or more
trains to an alternate route includes evaluating the metrics for
each train planned for the selected route and selecting the train
having the highest metrics for rescheduling on an alternate route.
Description
RELATED APPLICATIONS
[0001] This application is a continuation in part of application
Ser. No. 10/785,059 filed Feb. 25, 2004, claiming the benefit of
U.S. Provisional Application 60/449,849 filed on Feb. 27, 2003.
[0002] This application is also one of the below listed
applications being concurrently filed:
[0003] GEH01 00166 application Ser. No. ______ entitled "Scheduler
and Method for Managing Unpredictable Local Trains";
[0004] GEH01 00167 application Ser. No. ______ entitled "Method And
Apparatus For Optimizing Maintenance Of Right Of Way";
[0005] GEH01 00168 application Ser. No. ______ entitled "Method and
Apparatus for Coordinating Railway Line-Of-Road and Yard
Planners";
[0006] GEH01 00169 application Ser. No. ______ entitled "Method and
Apparatus for Selectively Disabling Train Location Reports";
[0007] GEH01 00170 application Ser. No. ______ entitled "Method And
Apparatus For Automatic Selection Of Train Activity Locations";
[0008] GEH01 00171 application Ser. No. ______ entitled "Method And
Apparatus For Congestion Management";
[0009] GEH01 00173 application Ser. No. ______ entitled "Method and
Apparatus for Estimating Train Location".
[0010] The disclosure of each of the above referenced applications
including those concurrently filed herewith is hereby incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0011] The present invention relates to the scheduling of movement
of plural units through a complex movement defining system, and in
the embodiment disclosed, to the scheduling of the movement of
freight trains over a railroad system, and specifically to the
alternating routing of trains through congested areas.
[0012] Systems and methods for scheduling the movement of trains
over a rail network have been described in U.S. Pat. Nos.
6,154,735, 5,794,172, and 5,623,413, the disclosure of which is
hereby incorporated by reference.
[0013] As disclosed in the referenced patents and applications, the
complete disclosure of which is hereby incorporated herein by
reference, railroads consist of three primary components (1) a rail
infrastructure, including track, switches, a communications system
and a control system; (2) rolling stock, including locomotives and
cars; and, (3) personnel (or crew) that operate and maintain the
railway. Generally, each of these components are employed by the
use of a high level schedule which assigns people, locomotives, and
cars to the various sections of track and allows them to move over
that track in a manner that avoids collisions and permits the
railway system to deliver goods to various destinations.
[0014] As disclosed in the referenced applications, a precision
control system includes the use of an optimizing scheduler that
will schedule all aspects of the rail system, taking into account
the laws of physics, the policies of the railroad, the work rules
of the personnel, the actual contractual terms of the contracts to
the various customers and any boundary conditions or constraints
which govern the possible solution or schedule such as passenger
traffic, hours of operation of some of the facilities, track
maintenance, work rules, etc. The combination of boundary
conditions together with a figure of merit for each activity will
result in a schedule which maximizes some figure of merit such as
overall system cost.
[0015] As disclosed in the referenced applications, and upon
determining a schedule, a movement plan may be created using the
very fine grain structure necessary to actually control the
movement of the train. Such fine grain structure may include
assignment of personnel by name as well as the assignment of
specific locomotives by number, and may include the determination
of the precise time or distance over time for the movement of the
trains across the rail network and all the details of train
handling, power levels, curves, grades, track topography, wind and
weather conditions. This movement plan may be used to guide the
manual dispatching of trains and controlling of track forces, or
provided to the locomotives so that it can be implemented by the
engineer or automatically by switchable actuation on the
locomotive.
[0016] The planning system is hierarchical in nature in which the
problem is abstracted to a relatively high level for the initial
optimization process, and then the resulting course solution is
mapped to a less abstract lower level for further optimization.
Statistical processing is used at all levels to minimize the total
computational load, making the overall process computationally
feasible to implement. An expert system is used as a manager over
these processes, and the expert system is also the tool by which
various boundary conditions and constraints for the solution set
are established. The use of an expert system in this capacity
permits the user to supply the rules to be placed in the solution
process.
[0017] Currently, a dispatcher's view of the controlled railroad
territory can be considered myopic. Dispatchers view and processes
information only within their own control territories and have
little or no insight into the operation of adjoining territories,
or the railroad network as a whole. Current dispatch systems simply
implement controls as a result of the individual dispatcher's
decisions on small portions of the railroad network and the
dispatchers are expected to resolve conflicts between movements of
objects on the track (e.g. trains, maintenance vehicles, survey
vehicles, etc.) and the available track resource limitations (e.g.
limited number of tracks, tracks out of service, consideration of
safety of maintenance crews near active tracks) as they occur, with
little advanced insight or warning.
[0018] Congestion inevitably occurs in the routing of trains and
often occurs in the same areas. Congestion is a significant
problem. The routing of trains into a congested area tends to
exacerbate the congestion and may result in deadlock. Because the
delay in the movement of trains is subject to cost constraints
including contract penalties, the tendency of dispatchers is to
continue to push trains through an area as rapidly as possible,
advancing their movement along the line of road whenever possible,
and treating the resulting congestion as a track availability
problem to be solved through the assignment of track resources to
create alternative routes through the congested area. The movement
planners used by dispatchers in adjacent territories are often
completely independent of each other and uninformed as to the
status of the tracks in adjacent territories. As a result,
dispatchers in uncongested areas may continue to send trains into a
congested area in the adjacent territory.
[0019] The present invention relates to the anticipation and
avoidance of congestion to maximize the throughput of trains in the
overall system at the expense of the movement of trains over
smaller sections of track.
[0020] Congestion generally is the after-the-fact result of acts
set in motion by dispatchers assisted by train movement planners,
i.e., by acts taken long prior to the development of actual
congestion. By the time that congestion is actually detected, other
trains are enroute through the congested area and in may cases have
passed the point in the system where an alternative route may have
been selected.
[0021] Typically, the routing of trains through areas of expected
congestion is handled by dispatchers utilizing tribal knowledge,
i.e., knowledge gained through the dispatcher's personal experience
and the experience of other dispatchers passed to him.
[0022] It is accordingly an object of the present invention to
reduce congestion and avoid deadlock by the management of the entry
of trains into a congested area.
[0023] These and many other objects and advantages of the present
invention will be readily apparent to one skilled in the art to
which the invention pertains from a perusal of the claims, the
appended drawings, and the following detailed description of the
preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWING
[0024] FIG. 1 is a simplified pictorial representation of one
embodiment of the present invention for use with a rail network
divided into control areas.
[0025] FIG. 2 is a simplified flow diagram for one embodiment of a
scheduling method that predicts the occurrence of congestion over a
selected route.
DETAILED DESCRIPTION
[0026] As illustrated in FIG. 1, the global rail network 105 can be
divided into one or more control areas 100 (100A-100C), each of
which has a dispatcher 110 (110A-110C) assigned to manage the
movement of trains (102) through his respective control area 100. A
centralized movement planner 120 provides a network based movement
plan for the global rail network 105 based on input received from
the railroad information support center 130. The railroad
information support center 130 provides information related to the
track resources and other information suitable to plan the use of
the resources. Centralized movement planner 120 generates a
movement plan for the resources in the track network 105 and
provides the plan to the automated dispatcher 140. Movement planner
120 may also received updates on the execution of the movement plan
from automated dispatcher 140 and can update the current movement
plan. Automated dispatcher 140 provides each of the dispatchers 110
with the movement plan to manage the train resources in their
respective control areas 110.
[0027] As described in the referenced applications, the automated
dispatcher 140 can be implemented using computer usable medium
having a computer readable code executed by special purpose or
general purpose computers. The automated dispatcher 140
communicates with trains 102 on the network of track via a suitable
communication link 150, such as a cellular telephone, satellite or
wayside signaling.
[0028] The dispatcher issues and approves the issuance of movement
authorities and track restrictions, schedule maintenance of way
activities and communicates with train crews, yard managers and
other railroad personnel consistent with an optimized operating
plan for the railroad. While the dispatcher will rely on the
movement planner to solve the complex problem of optimizing
movement of trains, the dispatcher will be actively involved in
entering the necessary data required to maintain an optimized plan
and identify exceptions to the plan.
[0029] As disclosed in the referenced applications, enhanced
planning is facilitated by automatically supplying the movement
planner 120 with information from the railroad information support
center 130 which associates train consist events (e.g., pickups,
crew changes, engine destinations) with planned train activities
that occupy track resources for the duration of a dwell time, so
that maintenance of the traditional train sheet data (via
electronic messaging and user data entry) is automatically
reflected in the train trip specifications for use for movement
planning.
[0030] From this information, and with the aid of suitable
conventional traffic flow analysis algorithms desirably embedded in
the movement planner 120, congestion in a particular geographic
area can be identified and the dispatchers in other areas advised
of the existence of the congestion and decline to push trains into
the congested area. Thus, traffic flow analysis algorithms can
detect and may also be used to predict the further occurrence of
congestion.
[0031] The present application also is directed to the
identification of areas that are prone to congestion and to take
action sufficiently in advance of the predicted congestion to
minimize or obviate avoid the congestion all together. In one
embodiment, the maintenance of a historical data base of events
that have resulted in congestion may be used in anticipating
congestion. For example, analysis of a historical database may
identify factors which are associated with congestion. Such factors
may be temporal, e.g., between 3:00 and 5:00 p.m. or seasonal,
e.g., during winter months, in nature. The factors may include
environmental conditions, track topography, type of train,
identification of crew, or other factors which may affect the
likelihood of congestion. Each factor may be assigned a metric as a
function of its contribution to the occurrence of congestion. The
factors may also be weighted depending on the contribution of the
factor. Through statistical analysis, it may be determined for a
particular route, that the planned usage of the route by its
scheduled trains may cause the cumulative metric for the route to
exceed a predetermined threshold indicating the likely occurrence
of congestion. The congestion metrics may be used by the movement
plan to schedule the trains to alternative routes in order to
reduce the metric for a given route to below the predetermined
threshold.
[0032] FIG. 2 illustrates one embodiment of the present
application. A method of scheduling the movement of trains may be
accomplished by predicting the occurrence of congestion due to the
planned movement of the trains over a selected route. Factors are
identified 200 which contribute to the congestion. The factors may
be identified through the collection and analysis of the historical
performance of trains over a selected route. Once the factors are
identified, a metric can be assigned to each factor 210 to account
for that factors contribution to congestion. The factor may be
weighted appropriately with relation to other factors, or may be
linked to other factors to account for the relationship that may
exist between factors. Each route can then be evaluated to
determine the probability of congestion based on the planned
movement of trains over the selected route. This can be
accomplished by evaluating the metrics for each planned movement of
a train over the selected route 220. If the cumulative metrics for
a given route exceed some predetermined threshold 230, one or more
of the planned movement of the trains can be rescheduled to an
alternate route 240.
[0033] In another embodiment, if the cumulative metrics for a route
exceed a predetermined threshold, a further evaluation can be done
to determine the contribution of each planned train to the
predicted congestion and the train contributing the most can be
selected for rescheduling to an alternate route.
[0034] These methods of scheduling may be implemented using
computer usable medium having a computer readable code executed by
special purpose or general purpose computers.
[0035] Other factors that may be considered to predict congestion
include train density, type of train, the identity of the
particular crew controlling a train, the type of load being carried
by the train, physical constraints of the train, network topography
including number of crossings, availability of sidings, zone
restrictions or curfews. The weighting of the factors can be based
upon historical statistics and can vary as a function of other
factors. For example, the weight of the train may be a factor that
is weighted more heavily in those areas where the track topography
factor indicates a steep incline.
[0036] The combined metric for a route need not exceed a
predetermined threshold to take steps to reduce the probability of
congestion. The metric for a route can be compared against a metric
for the same route with alternate planning to pick the planned
movement over the route that results in the lowest congestion
metric. Thus, a route metric evaluation can be performed for a
number of different planned movements over the route to select the
planned movement resulting in the lowest probability of
congestion.
[0037] Departure times may be delayed and/or safe places can be
found for trains en route along the line-of-road. Deadlocks may
thus be prevented and the alternate routes may remain unblocked for
use by the movement planner 120 in clearing the congestion.
[0038] While the delay of trains in uncongested areas may be
costly, this cost may pale in comparison to the savings achieved as
a result of the improvement of traffic flow through the system as a
whole.
[0039] While preferred embodiments of the present invention have
been described, it is understood that the embodiments described are
illustrative only and the scope of the invention is to be defined
solely by the appended claims when accorded a full range of
equivalence, many variations and modifications naturally occurring
to those of skill in the art from a perusal hereof.
* * * * *