U.S. patent application number 11/549747 was filed with the patent office on 2007-06-07 for apparatus and method for allowing user to track path of travel over extended period of time.
Invention is credited to Richard Ball, Bill Cross, Christopher Lalik.
Application Number | 20070126628 11/549747 |
Document ID | / |
Family ID | 38118162 |
Filed Date | 2007-06-07 |
United States Patent
Application |
20070126628 |
Kind Code |
A1 |
Lalik; Christopher ; et
al. |
June 7, 2007 |
APPARATUS AND METHOD FOR ALLOWING USER TO TRACK PATH OF TRAVEL OVER
EXTENDED PERIOD OF TIME
Abstract
An apparatus (10) and method for allowing a moving user to
automatically determine and store locations (11) over an extended
period of time, to display the series of such locations (11), and
to actively assist in returning to an earlier location. The
apparatus (10) includes an antenna (16) for facilitating satellite
lock, a fastening mechanism (18) for positioning the antenna (10)
for best reception, and a satellite lock indictor (20) for
communication loss of satellite lock. The apparatus (10) also
includes a time (26) for measuring an interval during which the
apparatus (10) is in a power-conserving sleep mode, and after which
the user's current location is automatically determined. Active
assistance in returning to an earlier location, either by traveling
back along the path earlier traveled or by traveling along a more
direct route, is accomplished by warning the user whenever the
user's course deviates from the path or route.
Inventors: |
Lalik; Christopher;
(Overland Park, KS) ; Cross; Bill; (Overland Park,
KS) ; Ball; Richard; (Overland Park, KS) |
Correspondence
Address: |
SPENCER, FANE, BRITT & BROWNE
1000 WALNUT STREET
SUITE 1400
KANSAS CITY
MO
64106-2140
US
|
Family ID: |
38118162 |
Appl. No.: |
11/549747 |
Filed: |
October 16, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10881459 |
Jun 30, 2004 |
7123189 |
|
|
11549747 |
Oct 16, 2006 |
|
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10845394 |
May 13, 2004 |
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10881459 |
Jun 30, 2004 |
|
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Current U.S.
Class: |
342/357.31 |
Current CPC
Class: |
G01S 19/34 20130101;
Y02D 10/00 20180101; G01S 19/51 20130101; G01C 21/20 20130101; G06F
16/29 20190101 |
Class at
Publication: |
342/357.13 |
International
Class: |
G01S 5/14 20060101
G01S005/14 |
Claims
1. An apparatus for actively assisting a user in returning to an
earlier geographic location, the apparatus comprising: a GPS
receiver for receiving signals from a plurality of orbiting
satellites and, based thereon, determining a geographic location of
the apparatus with respect to the orbiting satellites; a memory for
storing a series of the geographic locations, including a current
geographic location, corresponding to a movement of the apparatus
over time; and an input mechanism for allowing the user to identify
for the apparatus, from among the stored series of geographic
locations, the earlier geographic location to which the user
desires to return, and for allowing the user to select and identify
for the apparatus a return route, from among at least two possible
return routes, by which to return to the earlier geographic
location.
2. The apparatus as set forth in claim 1, wherein the return route
includes at least a portion of the series of geographic locations
between the current geographic location and the earlier geographic
location.
3. The apparatus as set forth in claim 1, wherein the return route
is the shortest route from the current geographic location to the
earlier geographic location.
4. The apparatus as set forth in claim 1, further including a
warning mechanism for communicating a warning to the user when the
user deviates from the return route while traveling back to the
earlier geographic location.
5. The apparatus as set forth in claim 4, wherein the warning
mechanism communicates the warning when the user deviates from the
return route by more than a pre-established amount.
6. The apparatus as set forth in claim 5, wherein the
pre-established amount is set by the user.
7. An apparatus for actively assisting a user in returning to an
earlier geographic location, the apparatus comprising: a GPS
receiver for receiving signals from a plurality of orbiting
satellites and, based thereon, determining a current geographic
location of the apparatus with respect to the orbiting satellites;
a timer for measuring a preestablished time interval during which
time the apparatus is in a power-conservation mode, and at the
expiration of which the GPS receiver automatically determines the
current geographic location of the apparatus, wherein the
preestablished time interval is repeatedly measured and the current
geographic location is repeatedly determined so as to result in a
series of geographic locations corresponding to a movement of the
apparatus over time; a memory for storing the series of geographic
locations; and an input mechanism for allowing the user to identify
for the apparatus, from among the stored series of geographic
locations, the earlier geographic location to which the user
desires to return, and for allowing the user to select and identify
for the apparatus a return route, from among at least two possible
return routes, by which to return to the earlier geographic
location.
8. The apparatus as set forth in claim 7, wherein the return route
includes at least a portion of the series of geographic locations
between the current geographic location and the earlier geographic
location.
9. The apparatus as set forth in claim 7, wherein the return route
is the shortest route from the current geographic location to the
earlier geographic location.
10. The apparatus as set forth in claim 7, further including a
warning mechanism for communicating a warning to the user when the
user deviates from the return route while traveling back to the
earlier geographic location.
11. The apparatus as set forth in claim 10, wherein the warning
mechanism communicates the warning when the user deviates from the
return route by more than a pre-established amount.
12. The apparatus as set forth in claim 11, wherein the
pre-established amount is set by the user.
13. A method of actively assisting a user in returning to an
earlier geographic location, the method comprising the steps of:
(a) determining and storing a series of geographic locations,
including a current geographic location, corresponding to a
movement of the user over time; (b) allowing the user to identify,
from among the stored series of geographic locations, the earlier
geographic location to which the user desires to return; and (c)
allowing the user to select a return route, from among at least
possible return routes, by which to return to the earlier
geographic location, and actively assisting the user in returning
to the identified earlier geographic location along the selected
return route.
14. The method as set forth in claim 13, wherein the return route
includes at least a portion of the series of geographic locations
between the current geographic location and the earlier geographic
location.
15. The method as set forth in claim 13, wherein the return route
is the shortest route from the current geographic location to the
earlier geographic location.
16. The method as set forth in claim 13, further including step
(d), after step (c), communicating a warning to the user when the
user deviates from the return route while traveling back to the
earlier geographic location.
17. The method as set forth in claim 16, wherein the warning is
communicated when the user deviates from the return route by more
than a pre-established amount.
18. The method as set forth in claim 17, wherein the
pre-established amount is based on a total distance to be traveled
between the current geographic location and the earlier geographic
location.
19. The method as set forth in claim 17, wherein the
pre-established amount is based on a total distance between the
current geographic location and a next geographic location in the
portion of the series of geographic locations included in the
route.
20. The method as set forth in claim 17, wherein the
pre-established amount is set by the user.
21. A method of actively assisting a user in returning to an
earlier geographic location, the method comprising the steps of:
(a) determining automatically and at pre-established intervals a
geographic location; (b) storing the automatically determined
geographic locations, including a current geographic location, as a
series of geographic locations corresponding to a movement of the
user over time; (c) allowing the user to identify, from among the
stored series of geographic locations, the earlier geographic
location to which the user desires to return; and (d) allowing the
user to select a return route, from among at least two possible
return routes, by which to return to the earlier geographic
location, and actively assisting the user in returning to the
identified earlier geographic location along the selected return
route.
22. The method as set forth in claim 21, wherein the return route
includes at least a portion of the series of geographic locations
between the current geographic location and the earlier geographic
location.
23. The method as set forth in claim 21, wherein the return route
is the shortest route from the current geographic location to the
earlier geographic location.
24. The method as set forth in claim 21, further including step
(e), after step (d), communicating a warning to the user when the
user deviates from the return route while traveling back to the
earlier geographic location.
25. The method as set forth in claim 24, wherein the warning is
communicated when the user deviates from the return route by more
than a pre-established amount.
26. The method as set forth in claim 25, wherein the
pre-established amount is based on a total distance to be traveled
between the current geographic location and the earlier geographic
location.
27. The method as set forth in claim 25, wherein the
pre-established amount is based on a total distance between the
current geographic location and a next geographic location in the
portion of the series of geographic locations included in the
route.
28. The method as set forth in claim 25, wherein the
pre-established amount is set by the user.
29. An apparatus for actively assisting a user in returning to an
earlier geographic location, the apparatus comprising: a GPS
receiver for determining a current geographic location of the
apparatus; a timer for repeatedly measuring a pre-established time
interval during which time the apparatus is in a power-conservation
mode, and at the expiration of which the GPS receiver automatically
determines the current geographic location of the apparatus,
resulting in a series of geographic locations corresponding to a
movement of the apparatus over time; a memory for storing the
series of geographic locations; an input mechanism for allowing the
user to identify for the apparatus, from among the stored series of
geographic locations, the earlier geographic location to which the
user desires to return, and for allowing the user to select and
identify for the apparatus a return route, from among at least two
possible return routes, by which to return to the earlier
geographic location; and a warning mechanism for communicating a
warning to the user when the user deviates from the selected return
route while traveling back to the earlier geographic location.
Description
RELATED APPLICATIONS
[0001] The present U.S. non-provisional patent application is a
continuation of an earlier-filed U.S. non-provisional patent
application of the same title, Ser. No. 10/881,459, filed Jun. 30,
2004, which was itself a continuation-in-part of an earlier-filed
U.S. non-provisional patent application of the same title Ser. No.
10/845,394, filed May 13, 2004. As such, the present application
claims, with regard to all common subject matter, priority benefit
of the identified earlier-filed applications, and hereby
incorporates by reference the earlier-filed applications in their
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates broadly to apparatuses and
methods for allowing a moving user to track his or her own movement
over time and for actively assisting the user in returning to an
earlier location. More particularly, the present invention concerns
an apparatus and method for allowing the moving user to
automatically periodically determine and store his or her own
current geographic locations over an extended period of time, and
to display the series of such locations as an indication of the
user's path of travel. Additionally, the present invention is
adapted and operable to actively assist the user in returning to an
earlier location, either by traveling back along the path earlier
traveled or by traveling along a more direct route.
[0004] 2. Description of the Prior Art
[0005] It is often desirable for a user to be able to determine his
or her own current geographic location, such as, for example, when
hiking, climbing, running, or otherwise traveling through unknown
or unfamiliar areas. This is accomplished in prior art devices
using global positioning system (GPS) technology, wherein signals
are received from a plurality of orbiting satellites and, based
thereon, location is determined with respect to the satellites.
Such GPS-based location-determining functionality is available in
hand-held prior art devices that can be carried by the user on his
or her person.
[0006] It is also desirable, however, for the user to be able to
view his or her previous locations so as to better understand his
or her path of travel over time. It will be appreciated that such
information is particularly useful when the user desires or needs
to backtrack or otherwise return along this path of travel. It will
also be appreciated that under some circumstances, such as, for
example, when traveling through rapidly changing terrain, locations
must be determined and stored relatively frequently in order to
provide the most complete and useful record. Furthermore, in order
to accommodate extended travel, the process must allow for
determining and storing locations in this manner for as long a
period as possible. Prior art devices exist for determining and
storing locations but, unfortunately, suffer from a number of
drawbacks and disadvantages.
[0007] Hand-held prior art devices exist, for example, that allow
the user to determine his or her current location and, if desired,
designate the location as a "waypoint". The waypoint is then stored
in memory and is available for later recall. Unfortunately, the
designation of waypoints requires active participation by the user.
Furthermore, the maximum number of waypoints that can be designated
is likely to be extremely limited because the waypoint concept
generally refers to a very limited number of special locations
designated for very particular purposes, not an unlimited number of
non-special locations designated merely for general record-keeping
purposes. It will be appreciated that a user, relying on waypoints
to provide a record of his or her previous locations may allow
undesirably long periods of time to pass between designations. When
the user does remember to make a designation, he or she may remove
the electronic device from its protective or carrying environment
only to find it impossible to quickly achieve the satellite lock
necessary to determine the current location, and so the user must
travel still further until the required lock can be established.
Also, in order to designate waypoints, the device must either be
left on continuously, thereby draining power and severely limiting
both the amount of time in which new waypoints may be designated
and the amount of time in which stored waypoints may be recalled,
or the device must be turned on and off each time a designation is
made. Turning the device on and off in this manner can itself
result in a substantial power drain, and so the frequency with
which waypoints are designated must be reduced. Thus, these
particular prior art devices do not provide a practical and
reliable mechanism for creating a record of the user's previous
locations in such a manner as to allow for better understanding his
or her path of travel.
[0008] More capable hand-held prior art devices exist that allow
for creating a more complete and reliable record of previous
locations automatically and without the drawbacks associated with
using waypoint technology for this purpose. Unfortunately, these
prior art devices quickly deplete their battery power, and once the
power fails, no further locations are determined and the user can
no longer display the record of previous locations. If the user
travels for longer than a few hours with no ability to charge the
battery, he or she will not be able to display the path of travel
if the need arises to backtrack, creating a potentially dangerous
situation.
[0009] Large-scale prior art systems also exist that allow for
remotely tracking the locations of multiple vehicles over time.
Such systems typically comprise a plurality of location-determining
mechanisms, each being affixed to or otherwise associated with one
of the remote and moving vehicles, and a central receiving and
processing station for receiving location data from the
location-determining mechanisms and for plotting such location data
over time. Unfortunately, because the location-determining
mechanisms are carried on vehicles, there are none of the weight,
size, or power consumption restrictions that a hand-held device
would require. Thus, internal processors have ample power and
antennas are both large and fixed. Furthermore, while providing the
location data to the central station for plotting does provide a
record of travel over time to those at the central station,
returning this information to the vehicle would require an
additional receiver, memory, and display at the
location-determining mechanism, and an additional transmitter at
the central station. It will therefore be appreciated that these
prior art systems are neither useful nor feasibly adaptable for
solving the present problem of allowing hikers and other traveling
individuals to save and recall their previous locations so as to
better understand their path of travel.
[0010] Due to the above-identified and other problems and
disadvantages in the art, a need exists for an improved apparatus
or method for allowing a moving user to track his or her own
movement over time and to assist the user in returning to an
earlier location.
SUMMARY OF THE INVENTION
[0011] The present invention overcomes the above-described and
other problems and disadvantages in the prior art by providing an
apparatus and method for allowing a moving user to automatically
periodically determine and store his or her own current geographic
locations over an extended period of time, to display the series of
such locations as an indication of the user's path of travel, and
to actively assist the user in returning to an earlier location,
either by traveling back along the path earlier traveled or by
traveling along a more direct route.
[0012] In a preferred embodiment, the apparatus broadly comprises a
housing; a GPS receiver; an antenna, including a fastening
mechanism and a satellite lock indicator; a processor; a battery; a
timer; a memory; a display; and an input mechanism. In normal
operating mode, the apparatus functions in a substantially
conventional manner to determine and display the user's current
geographic location when desired. In a forward tracking mode,
however, the apparatus takes steps to conserve power while
automatically periodically determining and storing such
locations.
[0013] The housing substantially encloses and protectively houses
the sensitive components of the apparatus, protecting them from
water, moisture, dust, and other environmental hazards. The GPS
receiver functions, in a substantially conventional manner, to lock
onto and receive signals from a plurality of orbiting satellites
and, based thereon, to determine the current geographic location of
the apparatus and the user with respect to the satellites. The
antenna is connected to the GPS receiver and facilitates reception
of the satellite signals used by the GPS receiver to determine
location. The fastening mechanism is connected to the antenna and
allows for removably coupling the antenna with an item worn or
carried by the user. This feature allows for positioning the
antenna for best reception of the satellite signals and, if the
lock indicator is incorporated into the fastening mechanism, for
locating the lock indicator for best visibility or audibility by
the user. The satellite lock indicator functions, when the
apparatus is in tracking mode, to communicate to the user that
either the satellite lock necessary for the GPS receiver to
determine the user's current location has not been achieved or that
the ability of the battery to provide power is critically low. It
will be appreciated that this feature is especially important and
advantageous as the user might, without such a warning, travel for
a substantial time or distance with no corresponding locations
stored in the memory.
[0014] The processor controls, in a substantially conventional
manner, internal electronic operation of the apparatus and
coordinates functioning of the various other components, as
appropriate, in both normal and tracking modes. The battery
provides power to the various other components of the apparatus
that require power in order to operate. It will be appreciated that
the ability or capacity of the battery to provide such power is
limited, and therefore it is an important feature of the present
invention to make the most efficient use of this ability or
capacity in order to extend and maximize the usefulness of the
apparatus, particularly its ability to continue tracking the user's
movement over time.
[0015] The timer measures, in tracking mode, a preestablished time
interval during which the apparatus is in a "sleep" or minimum
power consumption mode. At the end of the interval, the GPS
receiver automatically determines the user's current location,
which is then stored in the memory. Once the current location is
determined and stored, the apparatus automatically re-enters the
sleep mode and the timer-measured interval begins again. This
process automatically repeats so long as the apparatus is in
tracking mode. The memory receives, stores, and provides for
recalling the series of locations determined by the GPS receiver.
It will be appreciated that this series of locations, when
displayed simultaneously, corresponds to or reflects the user's
path of travel over time. The display displays the current
location, as determined by the GPS receiver; the series of
locations stored in the memory; and any other desired information.
When the apparatus is in tracking mode, the display is
automatically turned off in order to conserve power and thereby
extend or maximize the usefulness of the apparatus. The input
mechanism allows the user to provide input to the processor and
other components.
[0016] As mentioned, the apparatus also includes a return tracking
mode to actively assist the user in returning to an earlier
location. Once the user identifies an earlier location from among
the stored series of locations, and indicates whether he or she
wishes to return to that location either by traveling back along
the path earlier traveled or by traveling along a more direct
route, the apparatus actively assists the user in doing so. This is
accomplished by actively (e.g., visually or audibly) warning the
user whenever his or her course deviates by a pre-established
amount from the return path or route.
[0017] Thus, it will be appreciated that the apparatus of the
present invention provides a number of substantial advantages over
the prior art, including, for example, increased usefulness and
safety resulting from being able to track automatically for at
least 24 hours and preferably between 36 hours and 48 hours, which
is substantially longer than is possible with similar prior art
hand-held, battery-powered devices. Thus, the power conservation
features of the present invention advantageously enable it to
continue tracking long after prior art devices have depleted their
power and ceased to operate.
[0018] Furthermore, the present invention automatically
communicates to the user when a satellite lock cannot be
established and, as a result, the current location cannot be
determined. This is a particularly important feature given that the
present invention is adapted to be stowed in a backpack or
otherwise out of sight and function automatically. If this warning
feature were not present, then the user might not know when the
device fails to determine a current location and, as a result, the
series of geographic location representing the user's route over
time may again be dangerously incomplete.
[0019] Additionally, the return tracking mode or feature
advantageously frees the user from having to refer continuously to
the display by actively warning the user whenever his or her course
deviates by a pre-established amount from the return path or route,
thereby allowing the user to quickly adjust his or her course so as
to more reliably and efficiently return to the earlier
location.
[0020] These and other important features of the present invention
are more fully described in the section titled DETAILED DESCRIPTION
OF A PREFERRED EMBODIMENT, below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] A preferred embodiment of the present invention is described
in detail below with reference to the attached drawing figures,
wherein:
[0022] FIG. 1 is a block diagram of a preferred embodiment of the
apparatus of the present invention;
[0023] FIG. 2 is a flowchart of steps involved in a preferred
embodiment of a forward tracking mode or feature of the method of
the present invention, as may be implemented by the apparatus of
FIG. 1; and
[0024] FIG. 3 is a flowchart of steps involved in a preferred
embodiment of a return tracking mode or feature of the method of
the present invention, as may be implemented by the apparatus of
FIG. 1.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0025] With reference to the figures, an apparatus 10 and method
for allowing a moving user to automatically track his or her own
movement over time is herein described, shown, and otherwise
disclosed in accordance with a preferred embodiment of the present
invention. More specifically, the apparatus 10, in a forward
tracking mode or feature, allows the moving user to automatically
periodically determine and store his or her own current geographic
locations over an extended period of time and to display the series
of such locations 11 as an indication of the user's path of travel,
and, in a return tracking mode or feature, actively assists the
user in returning to an earlier location, either by traveling back
along the path earlier traveled or by traveling along a more direct
route. The apparatus 10 accomplishes these functions with features
for conserving power and communicating loss of the satellite lock.
Because the apparatus 10 is meant to be hand-held and carried by
hikers, climbers, sportsmen, athletes, and the like, it will be
appreciated that it is limited to an appropriate and practical
maximum size and weight.
[0026] In a preferred embodiment, referring particularly to FIG. 1,
the apparatus 10 broadly comprises a housing 12; a GPS receiver 14;
an antenna 16 including a fastening mechanism 18 and a satellite
lock indicator 20; a processor 22; a battery 24; a timer 26; a
memory 28; a display 30; and an input mechanism 32. In normal
operating mode, the apparatus 10 functions in a substantially
conventional manner to determine and display the user's current
geographic location when desired. In tracking mode, however, the
apparatus 10 takes steps to conserve power while automatically
periodically determining and storing such locations.
[0027] The housing 12 substantially encloses and protectively
houses the GPS receiver 14, processor 22, battery 24, timer 26,
memory 28, display 30, and any other similarly sensitive components
of the apparatus 10. The housing 12 is preferably a two-piece
clamshell design constructed of lightweight, high-impact plastic,
or another similarly suitable material, which, when assembled, is
substantially sealed (using, e.g., gaskets seals, or other
appropriate sealing mechanisms) against water, moisture, dust, and
other environmental hazards that might otherwise adversely affect
the sensitive components. It will be appreciated that, due to the
hand-carried nature of the apparatus 10, the design and
construction of the housing 12, as well as substantially all other
components of the apparatus 10, is limited with respect to the
aforementioned maximum allowable size and weight.
[0028] The GPS receiver 14 functions, in a substantially
conventional manner, to lock onto and receive signals from a
plurality of orbiting satellites 34 and, based thereon, to
determine the current geographic location of the apparatus 10 and
the user with respect to the satellites 34. This location may be
formatted by the GPS receiver 14 in terms of longitudinal and
latitudinal coordinates or any other appropriate coordinate
system.
[0029] The antenna 16 is connected to the GPS receiver 14 and
facilitates reception of the satellite signals used by the GPS
receiver 14 to determine location. The antenna 16 may be an active
antenna, a wireline antenna, an extendable antenna, a wireless
remote antenna, or other type of suitable antenna design. The
fastening mechanism 18 is connected to the antenna 16 and allows
for removably coupling the antenna 16 with a backpack, article of
clothing, or other item worn or carried by the user. This feature
allows for positioning the antenna 16 for best reception of the
satellite signals and, if the lock indicator 20 is incorporated
into the fastening mechanism 18, for locating the lock indicator 20
for best visibility or audibility by the user. The fastening
mechanism 18 may include, for example, a clasp, clip, hook,
hook-and-loop material, or other suitable coupling structure or
material.
[0030] The satellite lock indicator 20 functions, when the
apparatus 10 is in tracking mode, to visually, audibly,
vibratorily, or otherwise communicate to the user that either the
satellite lock necessary for the GPS receiver 14 to determine the
user's current location has not been achieved or that the ability
of the battery 24 to provide power is critically low. The lock
indicator 20 may be used to show both good and bad states, wherein,
for example, a slow pulsing or other scheme might be used to
indicate a good satellite lock and sufficient battery power, a
rapid pulsing might be used to indicate a loss of satellite lock,
and no pulsing might be used to indicate low battery power.
Preferably, when the satellite lock is lost, the apparatus 10
initiates a re-start routine that makes a preset number (e.g., two
to five) of attempts to re-establish the lost satellite lock before
communicating the loss to the user via the lock indicator 20. This
preset number may be set by the user. As mentioned, the lock
indicator 20 may be incorporated into the fastening mechanism 18,
as shown in FIG. 1, so as to be better visible or audible when the
housed portion of the apparatus 10 is stowed in a backpack or
otherwise out of the user's immediate sight or hearing. Where the
lock indicator 20 is visual in nature (e.g., one or more LEDs), a
particular color (e.g., red) or blink rate (e.g., continuous or
periodic) may be used to communicate the aforementioned conditions.
Similarly, where the lock indicator 20 is audible in nature, a
particular continuous or periodic tone may be used. It will be
appreciated that this feature is especially important and
advantageous as the user might, without such a warning, travel for
a substantial time or distance with no corresponding locations
stored in the memory 28. The warning communicated by the lock
indicator 20 may be turned off by the user when desired.
[0031] Thus, the apparatus 10 can be packed or otherwise stored in
any convenient place, and the antenna 16 positioned using the
fastening mechanism 18 to best receive the satellite signals
necessary for the GPS receiver 14 to determine location. Unlike the
prior art, the apparatus 10 operates automatically when in tracking
mode and therefore need not be kept where it can be frequently
accessed for manual operation.
[0032] The processor 22 controls, in a substantially conventional
manner, internal electronic operation of the apparatus 10 and
coordinates functioning of the various other components, as
appropriate, in both normal and tracking modes.
[0033] The battery 24 provides power to the various other
components of the apparatus 10 that require power in order to
operate. It will be appreciated that the ability or capacity of the
battery 24 to provide such power is limited, and therefore it is an
important feature of the present invention to make the most
efficient use of this ability or capacity in order to extend and
maximize the usefulness of the apparatus 10, particularly its
ability to continue tracking the user's movement over time.
[0034] The timer 26 measures, in tracking mode, a preestablished
time interval of at least 10 seconds and preferably between 10
seconds and 60 seconds or between 10 seconds and 5 minutes or
longer. During this interval, the apparatus 10 is in a "sleep" or
minimum power consumption mode. At the end of the interval, the GPS
receiver 14 automatically determines the user's current location,
which is then stored in the memory 28. Once the current location is
determined and stored, the apparatus 10 automatically re-enters the
sleep mode and the timer-measured interval begins again. This
process automatically repeats so long as the apparatus 10 is in
tracking mode. The time interval may be preestablished by the user.
It will be appreciated that the length of the preestablished time
interval will depend to a great extent on balancing battery life
with user needs, and with consideration of such factors as, for
example, the desired tracking accuracy, the nature of the terrain,
and the speed with which the user is traveling.
[0035] The memory 28 receives, stores, and provides for recalling
the series of locations 11 determined by the GPS receiver 14. It
will be appreciated that this series of locations 11, when
displayed simultaneously, corresponds to or reflects the user's
path of travel over time. If the apparatus 10 is shut-down or loses
satellite lock, the stored locations are maintained in flash
memory.
[0036] The display 30 displays or otherwise communicates the
current location, as determined by the GPS receiver 14; the series
of locations 11 stored in the memory 28; and other desired
information. When the apparatus 10 is in tracking mode, the display
30 is automatically turned off in order to conserve power and
thereby extend or maximize the usefulness of the apparatus 10. The
display 30 can be turned back on very quickly when desired, but, so
long as tracking mode is engaged, the display 30 will automatically
turn off again after a preset period, such as, for example, 30
seconds or between approximately 20 second and 60 seconds, in order
to conserve power. The user can, as desired, navigate along the
displayed series of locations 11 between the initial location and
the last location.
[0037] The input mechanism 32 allows the user to provide input to
the processor 22 and other components, and is particularly
important to the return tracking mode or feature described
below.
[0038] Referring also to FIG. 2, it will be appreciated that the
present invention may alternatively be characterized as a method,
wherein the above-described apparatus 10 is an exemplary instance
of how the functionality of the method might be implemented in
hardware, software, firmware, or any appropriate combination
thereof. Broadly, the method, in its forward tracking mode or
feature, comprises the steps of, with a hand-held apparatus, (a)
allowing the moving user to select an operation mode involving
extended tracking, as depicted in box 110; (b) allowing the user to
select or otherwise establish a time interval between location
determinations, as depicted in box 112; (c) determining the user's
initial location automatically and saving the determined initial
location in a memory automatically, as depicted in box 114; (d)
entering a sleep mode to conserve power automatically, including
deactivating a display automatically, as depicted in box 116; (e)
measuring the preestablished time interval automatically, as
depicted in box 118; (f) exiting the sleep mode and attempting to
determine the user's current location at the end of the measured
time interval automatically, as depicted in box 120; (g)
communicating, if the user's current location cannot be
established, an indicator to the user that the attempt to determine
the user's current location failed, as depicted in box 122; (h)
storing, if the user's current location can be established, the
determined current location in the memory automatically, as
depicted in box 124; (i) repeating steps (d) through (h)
automatically until such time as the user deselects the extended
tracking mode or power is depleted, as depicted in box 126; and (j)
allowing the user to display the stored initial and current
locations simultaneously, as depicted in box 128, wherein the
series of stored initial and current locations 11 provide an
indication of the user's path of travel over time.
[0039] Prior to communicating, in step (g), the loss of the
satellite lock, the apparatus 10 may attempt to reacquire the
satellite lock a preset number of times, as depicted in box 130.
Only if these re-acquisition attempts are unsuccessful will the
problem be communicated.
[0040] As mentioned, the apparatus 10 also includes a return
tracking mode or feature to actively assist the user in returning
to an earlier location, either by traveling back along the path
earlier traveled (as represented by the stored series of locations)
or by traveling along a more direct route. It will be appreciated
that the situations in which such return may be desirable are many
and varied: the user may, for example, wish to return to the
earlier location in order to investigate some earlier-identified
object or place of interest or to return to a branching point in
the path, or the user may wish to backtrack along the path earlier
traveled in order to search for an item that may have been dropped
or otherwise inadvertently left behind; or the user may wish to
return along the same path rather than another route simply because
the path earlier traveled has already been determined to be safe
for travel; or, under other circumstances, particularly where speed
is desired, the user may wish to return to an earlier point on the
path by the most direct route possible.
[0041] Referring also to FIG. 3, the return tracking mode or
feature of the present invention may be characterized as a method
similar to the above-described forward tracking mode or feature.
Broadly, the method comprises the steps of (a) allowing the user to
identify the earlier location, from among the stored series of
locations 11, to which he or she desires to return, as depicted in
box 210; (b) allowing the user to select a return route by which to
return to the earlier location, as depicted in box 212; and (c)
communicating a warning to the user if the user deviates from the
return route back to the earlier geographic location. Steps (a) and
(b) may be accomplished using the input mechanism 32 to identify
the earlier location and select the return route.
[0042] As mentioned, the return route may involve traveling back
along the path earlier traveled. In effect, the user would travel
back to each location in the stored series of locations between the
user's current location and the earlier location destination.
Alternatively, the return route may be the shortest practical or
possible route from the user's current location to the earlier
location, which may or may not include traveling to any of the
intermediate locations.
[0043] The lock indicator 20 may be adapted to function also as a
warning mechanism for communicating the warning to the user, or a
separate warning mechanism may be provided in the apparatus 10. As
such, the warning mechanism 20 may be visual, audible, or vibratory
in nature or otherwise suitable to communicate to the user that he
or she has deviated from the return route. The warning mechanism 20
may be made to communicate its warning when the user deviates from
the return route by more than a pre-established amount. Preferably,
the pre-established deviation amount defaults to a crosstrack error
value based on an appropriate percentage, such as, for example,
approximately between 5%-15%, of the total distance to be traveled
or total distance remaining to be traveled to the desired earlier
location destination, or the total distance to the next
previously-determined location or total distance remaining to be
traveled to the next previously-determined location along the
return route to the desired earlier location destination.
Optionally, the pre-established deviation amount could be set by
the user in light of traveling conditions (e.g., light levels,
obstacles). Though the pre-established deviation amount could,
alternatively, be based on a difference between heading and
bearing, the warning mechanism 20 would likely activate too
frequently as the user adjusts his or her course to avoid trees and
other obstacles. Preferably, the user can deactivate the warning
mechanism 20 when desired.
[0044] From the preceding discussion it will be appreciated that
the apparatus of the present invention provides a number of
substantial advantages over the prior art, including, for example,
increased usefulness and safety resulting from being able to track
automatically for at least 24 hours and preferably between 36 hours
and 48 hours, which is substantially longer than is possible with
similar prior art battery-powered devices. More specifically, the
power conservation features of the present invention advantageously
enable it to continue tracking long after hand-held,
battery-powered prior art devices have depleted their power and
ceased to operate.
[0045] Furthermore, the present invention automatically
communicates to the user when a satellite lock cannot be
established and, as a result, the current location cannot be
determined. This is a particularly important feature given that the
present invention is adapted to be stowed in a backpack or
otherwise out of sight and function automatically. If this warning
feature were not present, then the user might not know when the
device fails to determine a current location such that the series
of locations representing the user's route over time may again be
dangerously incomplete.
[0046] Additionally, the return tracking mode or feature
advantageously frees the user from having to refer continuously to
the display by actively warning the user whenever his or her course
deviates by a pre-established amount from the return path or route,
thereby allowing the user to quickly adjust his or her course so as
to more reliably and efficiently return to the earlier
location.
[0047] Although the invention has been described with reference to
the preferred embodiments illustrated in the attached drawings, it
is noted that equivalents may be employed and substitutions made
herein without departing from the scope of the invention as recited
in the claims. It will be appreciated, for example, that the
apparatus may be provided with additionally complementary
functionality, as desired. Similarly, the method may be implemented
in any combination of hardware, software, or firmware, which need
not take the form of the particular embodiment of the apparatus
disclosed herein.
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