U.S. patent application number 12/348497 was filed with the patent office on 2009-10-08 for apparatus of calculating a navigation route based on estimated energy consumption.
This patent application is currently assigned to International Business Machines CorporatioN. Invention is credited to Ralf Altrichter, Dirk Heuzeroth, Gerd Kehrer, Martin Robert Raitza.
Application Number | 20090254266 12/348497 |
Document ID | / |
Family ID | 40349384 |
Filed Date | 2009-10-08 |
United States Patent
Application |
20090254266 |
Kind Code |
A1 |
Altrichter; Ralf ; et
al. |
October 8, 2009 |
APPARATUS OF CALCULATING A NAVIGATION ROUTE BASED ON ESTIMATED
ENERGY CONSUMPTION
Abstract
A system of calculating a navigation route based on an estimated
energy consumption value that assigns a distance weight coefficient
for each of the plurality of potential routes that corresponds to
an estimated distance energy consumption value. The system also
determines a cumulative interference weight coefficient for each of
the plurality of potential routes corresponding to an estimated
interference energy consumption value based on traversing at least
one interference event in the potential route. Each cumulative
interference weight coefficient may include a fixed event
interference weight coefficient, a probable event interference
weight coefficient, and a scheduled event interference weight
coefficient. The system then determines total route energy
consumption weight coefficients for each of the plurality of
potential routes by adding the distance and cumulative interference
weight coefficients, and selects a route from the plurality of
potential routes based on a lowest total route energy consumption
weight coefficient.
Inventors: |
Altrichter; Ralf;
(Filderstadt, DE) ; Heuzeroth; Dirk; (Stuttgart,
DE) ; Kehrer; Gerd; (Meckenheim, DE) ; Raitza;
Martin Robert; (Boeblingen, DE) |
Correspondence
Address: |
McGinn Intellectual Property Law Group, PLLC
8321 Old Courthouse Road, Suite 200
Vienna
VA
22182-3817
US
|
Assignee: |
International Business Machines
CorporatioN
Armonk
NY
|
Family ID: |
40349384 |
Appl. No.: |
12/348497 |
Filed: |
January 5, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12099116 |
Apr 7, 2008 |
7493209 |
|
|
12348497 |
|
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|
Current U.S.
Class: |
701/532 |
Current CPC
Class: |
G06Q 10/047 20130101;
G01C 21/3469 20130101 |
Class at
Publication: |
701/200 |
International
Class: |
G01C 21/34 20060101
G01C021/34 |
Claims
1. An apparatus for calculating a navigation route based on an
estimated energy consumption value, said apparatus comprising a
software driven user interface which: receives an origination
location and a destination location; determines a plurality of
potential routes based on map route data between said origination
location and said destination location; determines a cumulative
distance for each of said plurality of potential routes; assigns a
distance weight coefficient for each cumulative distance for each
of said plurality of potential routes, said distance weight
coefficient corresponding to an estimated distance energy
consumption value based on said determined cumulative distance;
determines a cumulative interference weight coefficient for each of
said plurality of potential routes, said cumulative interference
weight coefficient corresponding to an estimated interference
energy consumption value based on traversing at least one
interference on said potential route, said cumulative interference
weight coefficient comprises the sum of: a cumulative fixed event
interference weight coefficient; a cumulative probable event
interference weight coefficient; and a cumulative scheduled event
interference weight coefficient; determines total route energy
consumption weight coefficients for each of said plurality of
potential routes by adding said distance weight coefficients of
each of said plurality of potential routes to said corresponding
cumulative interference weight coefficients of each of said
plurality of potential routes; and selects a route from said
plurality of potential routes based on a lowest total route energy
consumption weight coefficient from said determined total route
energy consumption weight coefficients; wherein said cumulative
fixed event interference weight coefficient is calculated by adding
a value of: a cumulative change in altitude interference weight
coefficient based on a cumulative change in altitude between said
origination location and said destination location; a curve radius
interference weight coefficient based on a size of a curve radius
between said origination location and said destination location;
and a speed reducing feature interference weight coefficient based
on a feature that reduces travel speed between said origination
location and said destination location; a speed limit change
interference weight coefficient based on a feature where a speed
limit is changed between said origination location and said
destination location; a minimum speed limit interference weight
coefficient based on a feature of a minimum posted speed limit
between said origination location and said destination location;
wherein said probable event interference weight coefficient is
calculated by adding a value of: a probable event speed reducing
feature interference weight coefficient based on a feature that
reduces travel speed between said origination location and said
destination location; and wherein said scheduled event interference
weight coefficient is calculated by adding a value of: a scheduled
event speed reducing feature interference weight coefficient based
on a feature that reduces travel speed between said origination
location and said destination location; a speed limit change
interference weight coefficient based on a change in speed limit
between said origination location and said destination location;
and a traffic pattern schedule interference weight coefficient
based on historical data of traffic volume that reduces travel
speed between said origination location and said destination
location.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present Application is a Continuation Application of
U.S. patent application Ser. No. 12/099,116 filed on Apr. 7,
2008.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a navigation
route calculation system in mobile navigation systems or internet
navigation systems providing services where a system is employed to
calculate routes with the lowest energy consumption. Calculating
routes based on the lowest energy consumption may result in saving
energy even if a selected route may have a longer distance or may
take a longer time than another route.
[0004] 2. Description of the Related Art
[0005] Today's mobile navigation systems contain map information
stored on a local storage system, (hard disk, flash memory, etc.),
and offer a user interface driven by local software to calculate
the route from a specified start point to a specified target
destination. These navigation systems dynamically navigate the user
to the target destination using GPS signals to calculate the user's
current position.
[0006] Mobile navigation systems and network computer-based
navigation systems contain map information typically stored on a
mobile navigation system's local storage or in a networked computer
database. A user typically interacts via a software driven user
interface to enable selection and calculation of a route from a
specified origination location to a specified target
destination.
[0007] During the process of calculating a route, the navigation
system typically determines a number of alternative routes before
displaying the selected route to the user. Alternatively, the
navigation system predetermines which intermediate routes may be
used to calculate the final route based on certain user selected
parameters that affect total time and total distance values in
determining a route.
[0008] The user influences the calculation method by determining a
route typically based on the shortest travel time, the shortest
route, or a combination of these two options, i.e., an "optimized
route" including both features of travel time and distance.
Typically, navigation systems may select a navigation route based
on one of these three options depending on a user selected means of
travel, i.e., the route is to "optimized" for automobiles,
commercial vehicles, cyclists, pedestrians, etc.
[0009] To calculate a potential route, a navigation system
determines the overall distance by individually determining the
distance of each individual section of the route. Each individual
route section represents a general type of road, e.g., highway,
country road, inner city, etc.
[0010] These "road types" have specific characteristics which
influence the route calculation, and selection based on average
speed and limitations regarding specific vehicles, etc.
[0011] However, the prior art has not shown any capacity to select
a navigation route based on estimated energy consumption factors
affecting fuel economy that a traveler may encounter, for example,
the grade of particular portions of road in a route, or the number
of stops or potential delays in a route.
SUMMARY OF THE INVENTION
[0012] In view of the foregoing and other exemplary problems,
drawbacks, and disadvantages of the conventional methods and
structures, a purpose of the exemplary aspects of the present
invention is to provide a system of calculating a navigation route
based on an estimated energy consumption value.
[0013] An exemplary aspect of the present invention includes a
system for calculating a navigation route based on an estimated
energy consumption value, in which the system receives an
origination location and a destination location, determines a
plurality of potential routes based on map route data between the
origination location and the destination location, determines a
cumulative distance for each of the plurality of potential routes,
assigns a distance weight coefficient for each cumulative distance
for each of the plurality of potential routes, the distance weight
coefficient corresponding to an estimated distance energy
consumption value based on the determined cumulative distance,
determines a cumulative interference weight coefficient for each of
the plurality of potential routes, the cumulative interference
weight coefficient corresponding to an estimated interference
energy consumption value based on traversing at least one
interference on the potential route, the cumulative interference
weight coefficient comprises the sum of: a cumulative fixed event
interference weight coefficient, a cumulative probable event
interference weight coefficient, and a cumulative scheduled event
interference weight coefficient, determines total route energy
consumption weight coefficients for each of the plurality of
potential routes by adding the distance weight coefficients of each
of the plurality of potential routes to the corresponding
cumulative interference weight coefficients of each of the
plurality of potential routes, and selects a route from the
plurality of potential routes based on a lowest total route energy
consumption weight coefficient from the determined total route
energy consumption weight coefficients, wherein the cumulative
fixed event interference weight coefficient is calculated by adding
a value of: a cumulative change in altitude interference weight
coefficient based on a cumulative change in altitude between the
origination location and the destination location, a curve radius
interference weight coefficient based on a size of a curve radius
between the origination location and the destination location, and
a speed reducing feature interference weight coefficient based on a
feature that reduces travel speed between the origination location
and the destination location, a speed limit change interference
weight coefficient based on a feature where a speed limit is
changed between the origination location and the destination
location, a minimum speed limit interference weight coefficient
based on a feature of a minimum posted speed limit between the
origination location and the destination location, wherein the
probable event interference weight coefficient is calculated by
adding a value of: a probable event speed reducing feature
interference weight coefficient based on a feature that reduces
travel speed between the origination location and the destination
location, and wherein the scheduled event interference weight
coefficient is calculated by adding a value of: a scheduled event
speed reducing feature interference weight coefficient based on a
feature that reduces travel speed between the origination location
and the destination location, a speed limit change interference
weight coefficient based on a change in speed limit between the
origination location and the destination location, and a traffic
pattern schedule interference weight coefficient based on
historical data of traffic volume that reduces travel speed between
the origination location and the destination location.
[0014] Another exemplary aspect of the present invention includes
wherein the cumulative change in altitude interference weight
coefficient is calculated by determining a product of a distance
and an energy use coefficient based on an estimated grade.
[0015] Another exemplary aspect of the present invention includes
wherein the curve radius interference weight coefficient is
calculated by determining a product of a curve distance and a curve
radius coefficient inversely proportional to the radius of the
curve.
[0016] Another exemplary aspect of the present invention includes
wherein the speed reducing feature interference weight coefficient
is calculated by retrieving a value corresponding to an estimated
energy use when traversing the speed reducing feature.
[0017] Another exemplary aspect of the present invention includes
wherein the speed limit change interference weight coefficient is
calculated by a value corresponding to an estimated energy use when
one of speeding up to an increased speed limit, and slowing down to
a decreased speed limit.
[0018] Another exemplary aspect of the present invention includes
wherein the minimum speed limit interference weight coefficient is
calculated by determining a product of a distance and an estimated
energy use at a corresponding minimum speed limit.
[0019] Another exemplary aspect of the present invention includes
wherein the probable event speed reducing feature interference
weight coefficient is calculated by determining a product of a
maximum estimated energy use corresponding to traversing a speed
reducing feature and a probability of the speed reducing feature of
occurring.
[0020] Another exemplary aspect of the present invention includes
wherein the scheduled event speed reducing feature interference
weight coefficient is calculated by determining based on a schedule
if a speed reducing feature will be encountered, and if so, by then
retrieving a value corresponding to an estimated energy use when
traversing the speed reducing feature.
[0021] Another exemplary aspect of the present invention includes
wherein the speed limit change interference weight coefficient is
calculated by determining based on a schedule if a speed limit
change will be encountered, and if so, by retrieving a value
corresponding to an estimated energy use when one of speeding up to
an increased speed limit, and slowing down to a decreased speed
limit.
[0022] Another exemplary aspect of the present invention includes
wherein the traffic pattern schedule interference weight
coefficient is calculated by determining an additional estimated
energy use based on a time of day corresponding to a volume of
traffic.
[0023] Another exemplary aspect of the present invention includes
wherein the probable event interference weight coefficient is
calculated by adding a minimum energy use value to a product of a
maximum energy use value and a probability of the probable event to
occur.
[0024] Another exemplary aspect of the present invention includes
wherein the scheduled event interference weight coefficient is
calculated by adding a minimum energy use value to a product of a
maximum energy use value and a schedule coefficient, wherein the
schedule coefficient is "1" when a scheduled event is one of
occurring and scheduled to create an interference, and "0" when a
scheduled event is one of not occurring and scheduled to not create
an interference.
[0025] Another exemplary aspect of the present invention includes
wherein the scheduled event interference weight coefficient is
calculated by adding a minimum energy use value to a product of a
maximum energy use value and a schedule coefficient, and a traffic
volume coefficient, wherein the schedule coefficient is "1" when a
scheduled event is one of occurring and scheduled to create an
interference, and "0" when a scheduled event is one of not
occurring and scheduled to not create an interference, and wherein
the traffic volume coefficient is proportional to a value of
traffic volume and only increases the scheduled event interference
weight coefficient corresponding to additional traffic volume.
[0026] Another exemplary aspect of the present invention includes
an apparatus that calculates a navigation route based on an
estimated energy consumption value, the apparatus including a
device that receives an origination location and a destination
location, a route determining device that calculates a plurality of
potential routes based on map route data between the origination
location and the destination location, a distance calculating
device that determines a cumulative distance for each of the
plurality of potential routes, a distance weight coefficient
assigning device that assigns a distance weight for each cumulative
distance for each of the plurality of potential routes, the
distance weight coefficient corresponding to an estimated energy
consumption value based on the determined cumulative distance, a
cumulative interference weight coefficient determining device that
determines a cumulative interference weight coefficient for each of
the plurality of potential routes, the cumulative interference
weight coefficient corresponding to an estimated interference
energy consumption value based on traversing at least one
interference on the potential route, the cumulative interference
weight coefficient comprises the sum of: a cumulative fixed event
interference weight coefficient, a cumulative probable event
interference weight coefficient, and a cumulative scheduled event
interference weight coefficient, a total route energy consumption
weight coefficient determining device that determines a total route
energy consumption weight coefficient for each of the plurality of
potential routes by adding the distance weight coefficients of each
of the plurality of potential routes to the corresponding
cumulative interference weight coefficients of each of the
plurality of potential routes, and a route selecting device that
selects a route from the plurality of potential routes based on a
lowest total value energy consumption weight coefficient from the
determined total route energy consumption weight coefficients,
wherein the cumulative fixed event interference weight coefficient
is calculated by adding a value of: a cumulative change in altitude
interference weight coefficient based on a cumulative change in
altitude between the origination location and the destination
location, a curve radius interference weight coefficient based on a
size of a curve radius between the origination location and the
destination location, and a speed reducing feature interference
weight coefficient based on a feature that reduces travel speed
between the origination location and the destination location, a
speed limit change interference weight coefficient based on a
feature where a speed limit is changed between the origination
location and the destination location, a minimum speed limit
interference weight coefficient based on a feature of a minimum
posted speed limit between the origination location and the
destination location, wherein the probable event interference
weight coefficient is calculated by adding a value of: a probable
event speed reducing feature interference weight coefficient based
on a feature that reduces travel speed between the origination
location and the destination location, and wherein the scheduled
event interference weight coefficient is calculated by adding a
value of: a scheduled event speed reducing feature interference
weight coefficient based on a feature that reduces travel speed
between the origination location and the destination location, a
speed limit change interference weight coefficient based on a
change in speed limit between the origination location and the
destination location, and a traffic pattern schedule interference
weight coefficient based on historical data of traffic volume that
reduces travel speed between the origination location and the
destination location.
[0027] With its unique and novel features, the present invention
provides a method of calculating a navigation route based on
estimated energy consumption.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The foregoing and other exemplary purposes, aspects and
advantages will be better understood from the following detailed
description of an exemplary embodiment of the invention with
reference to the drawings, in which:
[0029] FIG. 1 illustrates a first exemplary embodiment of the
system of calculating a navigation route based on estimated energy
consumption showing a schematic diagram of alternate calculated
routes from the same origination and destination location,
according to an exemplary aspect of the present invention;
[0030] FIG. 2 illustrates a first exemplary embodiment of the
method of calculating a navigation route based on estimated energy
consumption, showing an interference event table, according to an
exemplary aspect of the present invention;
[0031] FIG. 3A illustrates a first exemplary embodiment of the
method of calculating a navigation route based on estimated energy
consumption showing a first portion of a logic flowchart, according
to an exemplary aspect of the present invention; and
[0032] FIG. 3B illustrates a first exemplary embodiment of the
method of calculating a navigation route based on estimated energy
consumption showing a second portion of a logic flowchart,
according to an exemplary aspect of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION
[0033] Referring now to the drawings, and more particularly to
FIGS. 1-3B, there are shown exemplary embodiments of the system and
structures of the present invention.
[0034] FIG. 1 illustrates a schematic diagram of how a navigation
system calculates potential routes between an origination location
2, (A), and a destination location 4, (B). The first route 6
includes a first portion 8 that is ten (10) units long, and a
second portion 10 that is fifteen (15) units long having a total
length of twenty-five (25) units long. The second route 12 includes
a first portion 14 that is five (5) units long, a second portion 16
that is four (4) units long, a third portion 18 that is twenty (20)
units long, and a final portion 20 that is five (5) units long,
having a total length of thirty-four (34) units long. Therefore,
the second route 12, thirty-four (34) units long, nine (9) units
longer than the first route 6.
[0035] However, assuming for the purpose of illustrating the
present invention, if the shorter first route 6, traverses a
mountain pass, and the longer second route 12 is at relatively the
same elevation, the navigation system of the prior art would
normally select the shorter first route 6 (or the faster route
based on an estimated total travel time).
[0036] Applicant's present invention allows for the calculation of
parameters having estimated energy consumption values to determine
the most economic route, that is, the route having the least
estimated energy consumption value. In the example above, the
present invention would identify either the topography of the
terrain for the first 6 and second 12 routes, or determine a
difference in elevation between each portion of the proposed
routes. Portions are the route having steeper grades would receive
a higher value indicating a greater estimated energy consumption
value, whereas portions of the route having a decline or a level
grade would receive a lesser value indicating a lower estimated
energy consumption value.
[0037] Each of these estimated energy consumption values are added
for each of the proposed routes and the determination is made as to
which route has the lowest estimated energy consumption value for
presentation to a user.
[0038] In determining an estimated energy consumption value, each
distance of every portion of the potential routes must be
calculated as is typically common in navigation systems of the
prior art. The present invention first calculates a distance weight
coefficient for each portion of the potential routes based on their
distances to estimate an energy consumption value based on the
distance of each portion. The present invention then calculates an
interference weight coefficient for each portion of the potential
routes based on any number of interference events that must be
traversed between the origination and destination locations. The
sum of the total distance weight coefficients and the total
interference weight coefficients for each route are compared, and
the route with the lowest estimated energy consumption value is
selected for presentation to a user.
[0039] FIG. 2 illustrates an interference event table 20 having
three categories of events: fixed interference events 22; probable
interference events 24; and, scheduled interference events 26. Each
category of these interference events will be described herein
below.
[0040] Fixed interference events 22 include calculated coefficients
representing: 1) a change in altitude between the origination and
destination locations, or between each portion of the potential
route, as briefly described above; 2) a curve radius; 3) speed
reducing features, including, A) stop signs, and B) roundabouts; 4)
speed limit changes; and, 5) minimum posted speed limits.
[0041] A cumulative change in altitude interference weight
coefficient is determined based on the cumulative change in
altitude between the origination location and the destination
location. One alternative method of calculating the cumulative
change in altitude interference weight coefficient is to take
merely the difference between the origination location and the
destination location. However, more accurate estimations of the
cumulative altitude interference weight coefficient may be
determined by the difference in altitude between each portion of
the potential route, or for even greater accuracy, determining a
difference in altitude along a fixed incremental distance.
[0042] A curve radius interference weight coefficient is based on a
size of a curve radius between the origination location and the
destination location. Smaller curve sizes require a larger
estimated energy consumption value; therefore the curve radius size
is inversely proportional to the estimated energy consumption
value.
[0043] A speed reducing feature interference weight coefficient may
be based on features that reduce travel speed between the
origination location and the destination location, for example,
stop signs and roundabouts at known locations that cause the
traveler to either stop or significantly reduce their speed.
[0044] A speed limit change interference weight coefficient is
based on the occurrence of a speed limit change in between the
origination location and the destination location. The change in
speed limit may be either increased or a decreased, yet in either
situation an estimated energy consumption value may be associated
with the corresponding weight coefficient. For example, an increase
in speed limit may require a greater interference weight
coefficient representing the increase in demand for fuel to achieve
the new speed limit. Alternately, a decrease in a speed limit may
indicate a lowering of the average fuel economy of a vehicle at a
decreased speed.
[0045] A minimum speed limit interference weight coefficient is
based on a minimum posted speed limit between the origination
location and the destination location. For example, a minimum speed
limit may be above a level where an optimum fuel economy for a
commercial vehicle is maintained. Portions of a proposed route may
include an interference weight coefficient corresponding to a high
minimum speed limit representing a larger value than portions of a
proposed route having a minimum speed limit where better fuel
economy is maintained.
[0046] Probable interference events 24 include calculated
coefficients representing: 1) speed reducing features including, A)
traffic lights, B) pedestrian crossings, C) livestock crossings, D)
train crossings, E) yield or right of ways, F) ferries without an
operation schedule, and G) particular weather features.
[0047] A probable speed reducing feature interference weight
coefficient may be based on features that reduced travel speed
between the origination location and the destination location where
there is some uncertainty as to whether a speed reducing feature
will occur when a traveler traverses it. Probability data may
include stored data accessed by the navigation system, or may
include data collected by navigation system in real-time, for
example, on mobile navigational systems. Each probable event has a
value from 1 to 99%, since it is not known whether each probable
event will occur, (i.e., 100%), or will not occur (i.e., 0%) at the
time a traveler encounters it.
[0048] Each of the above types of probable events has a
corresponding probable event interference weight coefficient based
on the product of a maximum estimated energy consumption value if
the probable event requires the traveler to completely stop, or a
significantly slowdown and a probability coefficient representing
the likelihood of the probable event requiring the traveler to
either stop or slow down.
[0049] Some of the above types of probable events may have a
constant value added to the probable event interference weight
coefficient such as the pedestrian crossing, where a traveler would
always slow down a certain amount, whether or not pedestrians are
actually in the crosswalk. An example of this may be a school zone
with a pedestrian crossing.
[0050] Additionally, particular weather features qualify for
probable events having an interference weight coefficient for
particular weather patterns, for example, a mountain pass that
frequently is snowed in, or a low-lying area often subject to dense
fog at a particular time of day or season.
[0051] Scheduled interference events 26 include calculated
coefficients representing: 1) speed reducing features including, A)
a stop sign with traffic volume, B) a roundabout with traffic
volume, C) a pedestrian/school crossing during school or known busy
pedestrian traffic hours, D) a train crossing on a schedule, E) a
yield/right of way with traffic volume, and, F) a ferry on an
operating schedule; 2) speed limit changes on a schedule; and 3) a
traffic pattern schedule.
[0052] A scheduled event interference weight coefficient may be
based on features that occur according to a predetermined schedule
that a traveler would encounter between the origination location
and the destination location. The scheduled events may have stored
schedules in a navigation system or a networked computer system, or
may include data schedules collected and modified in real-time by a
mobile navigation system.
[0053] A scheduled a speed reducing feature interference weight
coefficient may be based on scheduled features that reduce travel
speed between the origination location and the destination
location. For example, a stop sign, roundabout, and a yield/right
of way may all be subject to a traffic pattern schedule at certain
times today where an interference weight coefficient is increased
due to an increased volume of traffic according to a schedule.
[0054] A pedestrian/school schedule crossing interference weight
coefficient may be based on a schedule of a pedestrian/school
crossing, for example, during school zone hours. These crossing
interference weight coefficients may be increased due an increase
in the volume of pedestrian traffic according to a pedestrian
traffic/school zone schedule.
[0055] A train crossing schedule interference weight coefficient
may be calculated based on known train schedules and a length of
the train corresponding to duration of time at a particular train
crossing point. For example, if a train is scheduled to be at a
location at a particular time when a user would be traverse in a
train crossing, a train crossing interference weight coefficient
will be calculated based on the event of waiting for train.
Additionally, a traffic schedule interference weight coefficient
may be considered in conjunction with the train crossing
interference weight coefficient to take into account the larger
volume of stopped traffic at a particular time of the day according
to a traffic volume schedule.
[0056] Similar to the train crossing schedule interference weight
coefficient, a ferry schedule crossing interference weight
coefficient may be calculated based on a known ferry crossing
schedule and a length of crossing corresponding to the duration of
time when the particular ferry crosses between the origination and
destination locations. Additionally, a traffic schedule
interference weight coefficient may be considered in conjunction
with the ferry crossing interference weight coefficient to take
into account a larger volume of traffic to be moved via the ferry
at a particular time of day according to a traffic volume
schedule.
[0057] A speed limit change schedule interference weight
coefficient may be calculated based on a known schedule of a change
in speed limit. For example, as mentioned above, a school zone may
have a reduced speed limit during particular hours of school.
Additionally, as above, the traffic schedule interference weight
coefficient may be considered in conjunction with the speed limit
change interference weight coefficient to take into account the
large volume of traffic during a particular schedule speed limit
change time.
[0058] A traffic pattern schedule interference weight coefficient
may be used in concert with other interference weight coefficients,
as described above, or independently based merely on an estimated
traffic volume schedule.
[0059] FIGS. 3A and 3B illustrate the logic flowchart the method of
calculating a navigation route based on an estimated energy
consumption value of the present invention.
[0060] FIG. 3A illustrates the method of receiving an origination
and destination location 30 at a mobile navigation system or
computer networked navigation system. The navigation system then
determines potential routes between the received locations 32, and
determines the cumulative distance (D) for each of the potential
routes 34. The navigation system then assigns a distance weight
coefficient (Dw) for each potential route 36, and begins to
calculate it the cumulative interference weight coefficient (Iw)
for each potential route 38.
[0061] First, a determination of a cumulative fixed event
interference weight coefficient (Iw.sup.F) is made for each
potential route 40. The navigation system determines if there is a
change in altitude 42 between the origination and destination
locations, and if so, a calculated change in altitude coefficient
44 is determined. Next, the system determines if there is a small
curve radius 46, and if so, a calculated small curve radius
coefficient 48 is determined. Then, the system determines if there
is any speed reducing features 50 such as a stop sign 52, or a
roundabout 56, and if so, the system calculates a stop sign
coefficient 54, or a calculated roundabout coefficient 58,
respectively. FIG. 3B continues to illustrate that the system then
determines if there any speed limit changes 60, and if so, a
calculated speed limit change coefficient 62 is determined.
Finally, the system then determines any minimum posted speed limit
64, and if so, a calculated minimum speed limit coefficient 66 is
determined. Each of the above-calculated fixed event interference
weight coefficients are added together to arrive at the cumulative
fixed event interference weight coefficient 40, (Iw.sup.F).
[0062] Second, the determination of a cumulative probable event
interference weight coefficient (Iw.sup.P) is made for each
potential route 70. The navigation system determines if there are
any speed reducing features 72 such as a traffic light 74, a
pedestrian crossing 78, a livestock crossing 82, a train crossing
86, a yield/right of way 90, (as continued in FIG. 3B), a ferry
crossing 94, or a particular weather event 98, and if so, the
system calculates a traffic light coefficient 76, a pedestrian
crossing coefficient 80, a livestock crossing coefficient 84, a
train crossing coefficient 88, a yield/right of way coefficient 92,
a ferry crossing coefficient 96, and a weather condition
coefficient 100, respectively. Each of the above-calculated
probable event interference weight coefficients are added together
to arrive at a cumulative probable event interference weight
coefficient 70, (Iw.sup.P).
[0063] Third, the determination of a cumulative scheduled event
interference weight coefficient (Iw.sup.S) is made for each
potential route 110. The navigation system determines if there are
any speed reducing features 112 that are subject to a known
schedule such as stop sign 114 subject to a volume of traffic
according to a schedule, a roundabout 118 subject to a volume of
the traffic according to a schedule, a pedestrian crossing 122
subject to a schedule of pedestrian traffic, a train crossing 126
subject to a train crossing schedule, a yield/right of way 130
subject to a volume of traffic according to a schedule, (as
continued in FIG. 3B), and a ferry crossing 134 subject to a
scheduled crossing of a ferry. If any of the scheduled events
occur, the navigation system calculates a corresponding stop sign
coefficient 116, a roundabout coefficient 120, a pedestrian
crossing coefficient 124, a train crossing coefficient 128, a
yield/right of way coefficient 132, and a ferry crossing
coefficient 136, respectively.
[0064] Additionally, the navigation system determines if there is
any speed limit change 138 according to a schedule, and if so, the
navigation system calculates a speed limit change coefficient 140.
Also, the navigation system determines if there is any traffic
volume schedule 142 to be taken into account, and if so, the
navigation system calculates a traffic volume schedule coefficient
144. Each of the above-calculated scheduled event interference
weight coefficients are added together to arrive at a cumulative
scheduled event interference weight coefficient 110 (Iw.sup.S).
[0065] Navigation system then determines the total interference
weight coefficient Iw.sup.TOT for each potential route 150 by
adding together the cumulative fixed event interference weight
coefficient (Iw.sup.F), the cumulative probable event interference
weight coefficient (Iw.sup.P), and the cumulative scheduled event
interference weight coefficient (Iw.sup.S). Thereafter, the
navigation system determines the total energy consumption efficient
(E.sup.TOT) for each potential route 152 by adding the distance
weight coefficient (Dw) and the total interference weight
coefficient (Iw.sup.TOT) for each potential route.
[0066] The navigation system then selects the route based on the
lowest total energy consumption coefficient value 154.
[0067] While the invention has been described in terms of one or
more exemplary embodiments, those skilled in the art will recognize
that the invention can be practiced with modification within the
spirit and scope of the appended claims. Specifically, one of
ordinary skill in the art will understand that the drawings herein
are meant to be illustrative, and the design of the inventive
assembly is not limited to that disclosed herein but may be
modified within the spirit and scope of the present invention.
[0068] Further, Applicant's intent is to encompass the equivalents
of all claim elements, and no amendment to any claim the present
application should be construed as a disclaimer of any interest in
or right to an equivalent of any element or feature of the amended
claim.
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