United States Patent |
6,114,957 |
Westrick , et al. |
September 5, 2000 |
Pet locator system
Abstract
A system for locating movable objects and detecting the failure of the object
to visit a designated area within a predetermined time, including a base unit, a
transceiver attached to the movable object, and a locating device. The base unit
includes a transmitter circuit which generates a first signal for substantially
continuous transmission within a zone, which encompasses the designated area.
When the movable object enters the zone, the receiver portion of the transceiver
receives the first signal and resets a timer within the transceiver. If the
movable object fails to revisit the zone within the predetermined time, based on
predictions of the movable object's movements, the timer times out and switches
the transceiver transmitter into an active mode wherein the transceiver emits a
second signal. The second signal, which may contain information identifying the
movable object, can be detected by using a portable locating device having a
directional antenna which is used to track down and recover the movable object.
In an alternate embodiment, a fixed mast-mounted locator receiver detects the
second signal and provides information regarding the approximate location of the
movable object.
Inventors: |
Westrick; Michael D. (Fort Wayne, IN);
Brune; Scott A. (Leo, IN) |
Assignee: |
Innotek Pet Products, Inc. (Garrett, IN)
|
Appl. No.: |
026058 |
Filed: |
February 19, 1998 |
Current U.S. Class: |
340/568.1; 340/529; 340/539;
340/573.3; 340/573.4 |
Intern'l Class: |
G08B 021/18; G08B 021/22 |
Field of Search: |
340/573.3,573.4,568.1,539,529
|
References Cited
U.S. Patent Documents
2881410 |
Apr., 1959 |
Brunn |
340/825. |
3336530 |
Aug., 1967 |
Sloan et al. |
340/573. |
4177466 |
Dec., 1979 |
Reagan |
342/456. |
4596988 |
Jun., 1986 |
Wanka |
342/457. |
4742357 |
May., 1988 |
Rackley |
342/457. |
4799062 |
Jan., 1989 |
Sanderford, Jr. et al. |
342/450. |
4814751 |
Mar., 1989 |
Hawkins et al. |
340/573. |
4818998 |
Apr., 1989 |
Apsell et al. |
342/444. |
4961575 |
Oct., 1990 |
Perry |
340/539. |
4980671 |
Dec., 1990 |
McCurdy |
340/573. |
5021794 |
Jun., 1991 |
Lawrence |
340/539. |
5067441 |
Nov., 1991 |
Weinstein |
119/29. |
5115223 |
May., 1992 |
Moody |
340/573. |
5196825 |
Mar., 1993 |
Young |
340/573. |
5212912 |
May., 1993 |
Foissac |
52/40. |
5268670 |
Dec., 1993 |
Brasch et al. |
49/502. |
5289163 |
Feb., 1994 |
Perez et al. |
340/573. |
5337041 |
Aug., 1994 |
Friedman |
340/573. |
5461390 |
Oct., 1995 |
Hoshen |
340/573. |
5525967 |
Jun., 1996 |
Azizi et al. |
340/573. |
5543780 |
Aug., 1996 |
McAuley et al. |
340/573. |
5552772 |
Sep., 1996 |
Janky et al. |
340/573. |
5557259 |
Sep., 1996 |
Musa |
340/573. |
5589821 |
Dec., 1996 |
Sallen et al. |
340/573. |
5603094 |
Feb., 1997 |
Greear, Jr. |
340/573. |
5621388 |
Apr., 1997 |
Sherburne et al. |
340/573. |
5629678 |
May., 1997 |
Gargano et al. |
340/573. |
5635907 |
Jun., 1997 |
Bernard et al. |
340/573. |
5650769 |
Jul., 1997 |
Campana, Jr. |
340/573. |
5652578 |
Jul., 1997 |
Snow |
340/539. |
5686887 |
Nov., 1997 |
Chen et al. |
340/539. |
5714932 |
Feb., 1998 |
Castellon et al. |
340/539. |
Other References
WatchMate.RTM. LC Product Catalogue by Instantel
consisting of 4 pages. WatchMate.TM. Product Catalogue by Instantel
consisting of 6 pages. Double Protection product brochure by Care
Trak, Inc. consisting of 4 pages. Hertz Supply letter dated Jun. 5,
1997, written by James M. Copp, consisting of 3 pages. Guardian
Net.TM. product brochure by Guardian Electronics, Inc. consisting of 4
pages. Care Trak Inc. product brochure for Wrist Transmitter Bracelet
consisting of 2 pages. Secure Care Products.TM. product brochure for
Wandering Resident Systems consisting of 1 page. WanderGuard.RTM. a
division of Senior Technologies, Inc. product brochure consisting of 2
pages. WatchMate.TM. LC product brochure by Instantel consisting of 2
pages. WatchMate.RTM. System Product brochure by Instantel, 1995,
consisting of 4 pages. The BedNet.TM. system product brochure
consisting of 4 pages. Secure Care Products Wandering Resident Systems
brochure consisting of 1 page. |
Primary
Examiner: Swann; Glen
Attorney, Agent or Firm: Taylor & Aust,
P.C.
Claims
What is claimed is:
1. A system for locating movable objects,
comprising: a transmitter circuit, the transmitter circuit generating a
first signal for transmission within a zone; a transceiver attached to
the movable object, the transceiver including a receiver capable of receiving
the first signal when the movable object is within the zone, a timer responsive
to the receiver for measuring elapsed time between received first signals, and a
transmitter being switched by the timer into an active mode when the elapsed
time exceeds a predetermined time limit, the transmitter transmitting a second
signal when in the active mode; and a programming unit configured for
remotely programming said transceiver.
2. A system according to claim 1
wherein the transmitter circuit is connected to a 110 volt alternating current
power source.
3. A system according to claim 1 wherein the transmitter
circuit is connected to a battery.
4. A system according to claim 1
further comprising a collar for adjustable attachment to the movable object, the
transceiver being connected to the collar.
5. A system according to
claim 1 wherein the zone is approximately 10 feet in diameter.
6. A
system according to claim 1 wherein the transmitter circuit continuously
transmits the first signal as a pulse code modulated signal at a frequency below
approximately 20 kilohertz.
7. A system according to claim 1 wherein the
transceiver further includes a waterproof housing which encloses the receiver,
the timer, and the transmitter.
8. A system according to claim 1 wherein
the transceiver transmitter transmits the second signal at a frequency in the
range of approximately 216 to 221 megahertz.
9. A system according to
claim 1 wherein the transceiver is programmable.
10. A system according
to claim 1 wherein the second signal contains identification information to
identify the transceiver.
11. A system according to claim 1 wherein the
transceiver includes a beeper.
12. A system according to claim 1 wherein
the transceiver is connected to a battery.
13. A system according to
claim 12 wherein the transceiver indicates a low power condition of the battery.
14. A system according to claim 1 further comprising a locating device
for receiving the second signal, thereby permitting location of the movable
object.
15. A system according to claim 14 wherein the locating device
is connected to a display.
16. A system according to claim 14 wherein
the locating device is connected to a keyboard.
17. A system according
to claim 14 wherein the locating device is portable.
18. A system
according to claim 14 wherein the locating device is a super-heterodyne,
direction-finding receiver.
19. A system according to claim 14 wherein
the locating device includes a meter to indicate the signal strength of the
second signal.
20. A system according to claim 14 wherein the locating
device includes a tuner for adjusting the reception frequency of the locating
device.
21. A system according to claim 1 further comprising a
stationary locating device for receiving the second signal.
22. A system
according to claim 1 further comprising a mast-mounted locating device for
receiving the second signal.
23. A system for locating movable objects,
comprising: a transmitter circuit, the transmitter circuit generating a
first signal for transmission within a zone; a transceiver attached to
the movable object, the transceiver including a receiver capable of receiving
the first signal when the movable object is within the zone, a timer responsive
to the receiver for measuring elapsed time between received first signals, and a
transmitter being switched by the timer into an active mode when the elapsed
time exceeds a predetermined time limit, the transmitter transmitting a second
signal when in the active mode; and a locating device for receiving the
second signal, thereby permitting location of the movable object, the locating
device including a receiving section and an adjustable attenuator for varying a
gain of the receiving section.
24. A system for locating movable
objects, comprising: a transmitter circuit, the transmitter circuit
generating a first signal for transmission within a zone; a transceiver
attached to the movable object, the transceiver including a receiver capable of
receiving the first signal when the movable object is within the zone, a timer
responsive to the receiver for measuring elapsed time between received first
signals, and a transmitter being switched by the timer into an active mode when
the elapsed time exceeds a predetermined time limit, the transmitter
transmitting a second signal when in the active mode; and a stationary,
mast-mounted locating device for receiving the second signal.
25. A
system for locating movable objects, comprising: a transmitter circuit
including a signal generator, an oscillator, and an antenna for transmitting a
first signal within a zone encompassing an area regularly visited by the movable
object; and a transceiver attached to the movable object and connected
to a battery, said transceiver including a receiver having an antenna for
receiving the first signal when the movable object is within the zone, a timer
which begins measuring time whenever the receiver stops receiving the first
signal, and a transmitter connected to the timer having a signal generator, an
oscillator, an antenna for transmitting a second signal whenever the measured
time exceeds a predetermined time limit, and a beeper for indicating a low power
condition of the battery.
26. A system according to claim 24 wherein the
transceiver is connected to a collar which is worn by the movable object.
27. A system according to claim 24 wherein the transceiver is
programmable.
28. A system according to claim 26 wherein the second
signal contains identification information to identify the transceiver.
29. A system according to claim 24 further comprising a locating device
for receiving the second signal.
30. A system according to claim 30
wherein the locating device is portable and includes a super-heterodyne
direction-finding receiver.
31. A method for locating movable objects,
comprising the steps of: providing a transmitter circuit which generates
a first signal for transmission within a zone; providing a transceiver
for attachment to the movable object, the transceiver including a receiver
capable of receiving the first signal when the movable object is within the
zone; setting a timer responsive to the receiver for measuring the
elapsed time between received first signals; switching a transmitter
responsive to the timer into an active mode when the elapsed time exceeds a
predetermined time limit; causing the transmitter to transmit a second
signal when in the active mode; providing a locating device for
receiving the second signal, thereby permitting location of the movable object;
and providing a tuner connected to the locating device for manually
adjusting the reception frequency of the locating device.
32. The method
of claim 31 further comprising the step of connecting the transceiver to a
collar for adjustable attachment to the movable object.
33. The method
of claim 31 wherein the step of providing a transmitter circuit includes
continuously transmitting the first signal as a pulse code modulated signal at a
frequency below approximately 20 kilohertz.
34. The method of claim 31
wherein the step of transmitting a second signal includes transmitting the
second signal at a frequency in the range of approximately 216 to 221 megahertz.
35. The method of claim 31 wherein the step of transmitting a second
signal includes transmitting a second signal containing identification
information to identify the transceiver.
36. The method of claim 31
further comprising the step of connecting the transceiver to a battery.
37. The method of claim 36 further comprising the step of indicating a
low power condition of the battery.
38. The method of claim 31 further
comprising the step of providing a meter connected to the locating device to
indicate the signal strength of the second signal.
39. A method for
locating movable objects, comprising the steps of: providing a
transmitter circuit which generates a first signal for transmission within a
zone; providing a transceiver for attachment to the movable object, the
transceiver including a receiver capable of receiving the first signal when the
movable object is within the zone; setting a timer responsive to the
receiver for measuring the elapsed time between received first signals;
switching a transmitter responsive to the timer into an active mode when
the elapsed time exceeds a predetermined time limit; causing the
transmitter to transmit a second signal when in the active mode; and
providing a stationary, mast-mounted locating device for receiving the
second signal.
Description
BACKGROUND OF THE INVENTION
The present invention relates
generally to a locator system, and particularly to a system for locating movable
objects, such as animals.
Movable objects, such as animals, regularly
visit specific, predictable locations in and/or around the owner's home. For
example, animals generally visit a food dish at least one time each day. It is
frequently desirable to permit such animals to move freely throughout the day,
without regard to their precise location, so long as the animal returns to the
particular, designated location within the home according to its predictable,
routine behavior. When the animal does not return to the designated location
within a predetermined time, it can frequently be assumed, based on the animal's
known behavior, that the animal has wandered away and must be located and
retrieved. As such, it is desirable to provide a system which enables a
transmitter worn by the animal to transmit a signal when the animal fails to
visit the designated area within the predetermined time so that the signal can
be received by a tracking or locator device.
SUMMARY OF THE INVENTION
The present invention provides a system for tracking and locating a
movable object, such as an animal, when the object remains outside a designated
area for a predetermined period of time. The system includes a base unit which
is a point of source transmitter that is placed in the designated area, such as
by the animal's food dish. The system further includes a transceiver worn by the
animal that has a receiver which receives an update signal transmitted by the
point of source transmitter whenever the animal enters the designated area. The
transceiver also includes a timer which is reset each time an update signal is
received. If the animal does not enter the designated area (i.e., the timer is
not reset by an update signal) within a predetermined time, the timer times out
and the transmitter included in the transceiver enters an active mode. When the
transmitter is in an active mode, it emits a high frequency tracking signal
which can be detected by a directional, portable locator antenna, or a
mast-mounted locator antenna.
Other objects, advantages and novel
features of the present invention will be apparent upon consideration of the
following description of embodiments of the invention and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic
perspective view of components of a locator system according to the present
invention shown employed as a pet locator system.
FIG. 2 is a
diagrammatic perspective view similar to FIG. 1.
FIG. 3 is a schematic
block diagram of the base unit and transceiver shown in FIGS. 1 and 2.
FIG. 4 is a schematic block diagram of the portable locating device
shown in FIG. 2.
FIG. 5 is a schematic block diagram of a
display/programming unit used in an alternate embodiment of the present
invention.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
The embodiments described herein are not intended to be exhaustive or to
limit the invention to the precise forms disclosed. Rather, the embodiments
selected for description are disclosed so that others skilled in the art may
utilize their teachings.
Although the following description presents the
system according to the present invention as a system for locating animals,
particularly, pets which are kept in or near a home, it should be understood
that the invention could readily be adapted, for example, to monitor and locate
farm animals, prisoners, children, vehicles, and other movable objects which are
to be kept within or routinely visit a specific area.
FIG. 1 depicts a
pet locating system according to the present invention generally including a
base unit 10 and a transceiver 12. Base unit 10 includes a low frequency
transmitter circuit 14 which generates and transmits a first signal 16 within a
zone 18 which encompasses the designated area. First signal 16 is substantially
continuously transmitted and provides the update signal for receipt by the
transceiver 12.
Transceiver 12 is mounted to a collar 20 which is
adjustably attached to the animal 22. In general, the receiver within
transceiver 12 receives first signal 16 (update signal) whenever animal 22
enters zone 18, for example, to eat food within food dish 24. Whenever
transceiver 12 receives first signal 16, a timer within transceiver 12
(described in greater detail below) is reset. The time out period for the timer
is set, based on the animal's behavioral patterns, such that the owner would
expect the animal to visit the designated area within the predetermined time
(for example, one day).
If the animal fails to enter zone 18 within the
predetermined time out period, a transmitter within transceiver 12 is switched
into an active mode as illustrated in FIG. 2. When in active mode, the
transmitter included within transceiver 12 emits a second signal 26 (a tracking
signal) as described in greater detail below. Transceiver 12 will continue to
emit second signal 26, so long as the battery power for transceiver 12 is
sufficient to generate the signal (for example, two to three days).
Once
it is determined that the animal has wandered off, the owner 28 can rent a
portable locating device or hand held locator 32 from the local pet supply
dealer 30. Locator 32 includes a high range, directional antenna as described
below. The owner 28 can use the locator 32 to track down and retrieve the animal
22. Alternatively, personnel at the pet supply dealer 30 can operate a
mast-mounted, long range locator receiver 34 to provide information on the
whereabouts of the animal.
As best shown in FIG. 3, base unit 10
includes a transmitter circuit 14 which is adapted to receive 110 volt,
alternating current power from a standard electrical outlet 36. Alternatively,
transmitter circuit 14 may be connected to a battery as shown in dashed lines in
FIG. 3. The power is routed to a power conditioning circuit 38 which supplies
power to the signal generator 40 which is connected to an oscillator 42. Signal
generator 40 provides a signal to amplifier 44 which is connected to antenna 46.
Antenna 46 transmits first signal 16 which, in an exemplary embodiment, is a
pulse code modulated signal at a frequency below approximately 20 kilohertz
within zone 18.
Transceiver 12 generally includes receiver 48, logic
unit 50, and transmitter 52, all housed within a waterproof housing. Receiver 48
includes an antenna 54 for receiving first signal 16. Antenna 54 is connected to
an amplifier 56 which is connected to logic unit 50. Logic unit 50 includes a
timer 58 and power input from a battery 60. Logic unit 50 is connected to
transmitter 52, particularly, to signal generator 64. Signal generator 64
receives a reference signal from oscillator 66. Signal generator 64 is connected
to amplifier 68. Amplifier 68 is connected to antenna 70 which emits second
signal 26 having a frequency preferably in the range of 216 to 221 megahertz.
The second signal 26 or tracking signal is received in an exemplary embodiment
by portable locating device 32 as shown in FIG. 4.
Signal generator 64
is also connected to a piezo beeper 67 which beeps (for example, once every
second) whenever transmitter 52 is activated. Beeper 67 thus provides an audible
indication of the location of animal 22. Beeper 67 is also used in the "battery
low" indicator function of transceiver 12. Logic unit 50 stores information
regarding the number and duration of transmission events. Based on the available
power from battery 60 and the power consumption of transceiver 12, one can
readily determine the total "activated" life of the battery. Logic unit 50 is
programmed with this information and enables beeper 67 when it determines, based
on the stored operational data, that battery 60 is nearly spent. Beeper 67 will
continue to beep until battery 60 is drained which may be, for example, two
months.
Portable locating device 32 features a microcontroller 72 (e.g.,
MC68HC705J1A), and an antenna 74 which is a direction finding, three element
antenna for receiving signals within the frequency range of 216-220 megahertz
(sometimes referred to as a superheterodyne, direction-finding receiver). The
signal from antenna 74 is amplified by amplifier 76 and routed to harmonic
filter/amplification stage 78, which includes a 216-220 megahertz filter. Stage
78 is connected to summing junction 80 which also receives an input from signal
processing section 82. A voltage controlled oscillator 84 provides an input to
signal processing section 82 and summing junction 88. Oscillator 84 is connected
to tuner frequency control potentiometer 86 which permits fine adjustment of the
oscillator output signal within a 5 kilohertz range from 10.2445 to 10.2455
megahertz. The output of summing junction 80 is connected to harmonic
filter/amplification stage 90 which includes a 10.7 megahertz filter having a 15
kilohertz bandwidth. Filter/amplification stage 90 is also connected to summing
junction 88. The output of summing junction 88 is connected to harmonic
filter/amplification stage 92 which includes a 455 kilohertz filter having a 15
kilohertz bandwidth. Summing junction 94 combines the output of
filter/amplification stage 92 and the signal from 455 kilohertz oscillator 96.
Oscillator 96 also provides a 455 kilohertz reference signal to microcontroller
72. Summing junction 94 is connected to amplifier 98 which, in turn, is
connected to harmonic filter/amplification stage 100. Stage 100 includes a 300
hertz base band filter. An additional 300 hertz base band filter is included in
filter/amplification stage 102, which also receives a 1 kilohertz on/off channel
tone from microcontroller 72. The output of the receiver section of portable
locating device 32 is provided to an external headphone jack 104, a signal
detector 106, and a 1 kilohertz piezo speaker 108. Detector 106 is connected to
signal strength meter 110 which is operably associated with back light LED 112.
The output of the 220 megahertz receiver is fed back to microcontroller 72.
Portable locating device 32 is powered by a 9 volt alkaline battery 114
which is fed through a voltage regulator 116 to provide the appropriate voltage
level for the locator electronics. The amplification stages included in the
receiver section of locating device 32 have adjustable gains. The gain of these
amplifiers is controlled by the voltage output of adjustable voltage regulator
118. By manually adjusting signal attenuator 120, output voltage V (GAIN) is
varied by adjustable voltage regulator 118. Consequently, the operator can
adjust the gain of the receiver relative to the signal strength of the second
signal 26 received by antenna 74. Finally an on/off switch 122 and a back light
control switch 124 are connected to microcontroller 72.
In operation,
base unit 10 is plugged into a 110 volt outlet 36 within the pet owner's home
located near an area regularly visited by animal 22. Base unit 10 then generates
and transmits a low frequency (e.g., 10 kilohertz) first signal 16. The strength
of first signal 16 decreases with distance from base unit 10. Zone 18 defines
the distance from base unit 10 within which first signal 16 can be detected by
transceiver 12 (typically around 10 feet). Power conditioning circuit 38 of base
unit 10 receives the 110 volt a/c power input and conditions the power signal to
produce a usable signal for powering transmitter circuit 14. Signal generator
40, based on its reference signal from oscillator 42, produces a low level
signal according to practices well known in the art. The low level signal is
amplified by amplifier 44 and transmitted as first signal 16 by antenna 46.
When animal 22 enters zone 18, transceiver 12 detects the presence of
first signal 16. Transceiver 12 begins normal functioning (i.e., exits initial
"standby" mode as shipped). Specifically, antenna 54 of receiver 48 receives
first signal 16, which is in turn amplified by amplifier 56. Amplifier 56
provides an update signal to logic unit 50, thereby resetting timer 58. Timer 58
begins counting down its predetermined time limit (e.g., 24 hours). As mentioned
above, the predetermined time limit is based on the known behavior of the animal
or may be set to a default value. Such a timer setting can be accomplished
according to various practices well known in the art. Since receiver 48
continuously detects the presence of first signal 16, timer 58 is continuously
reset or updated so long as animal 22 remains within zone 18.
When
animal 22 leaves zone 18 to go about its daily activities, timer 58 begins
counting down the predetermined time limit. If animal 22 does not return to zone
18 (to receive an update signal) within the predetermined time limit, timer 58
enables transmitter 52 of transceiver 12. Specifically, signal generator 64
generates a signal based on reference oscillator 66 which is amplified by
amplifier 68 using principles and practices commonly known in the art. The
signal from amplifier 68 is transmitted as a high frequency signal (e.g., 220
megahertz) by antenna 70. This signal, second signal 26, is transmitted
substantially continuously until battery 60 drains or switch 62 is switched off.
As mentioned above, second signal 26 is generated only after animal 22 has
deviated from its established behavioral patterns and is roaming. Second signal
26 provides a beacon or tracking signal to facilitate the location and recovery
of animal 22. Signal generator 64 also activates beeper 67 which provides an
audible indication of the location of animal 22.
Once pet owner 28
obtains a portable locating device 32, the owner simply points the device in
various directions to determine the approximate location of animal 22. The high
frequency second signal 26 is received by directional antenna 74 at a higher
intensity when antenna 74 is directed toward transceiver 12. If animal 22 has
traveled a relatively great distance from home, the owner 28 can adjust signal
attenuator 120 to its maximum position, thereby causing adjustable voltage
regulator 118 to output a voltage level corresponding to maximum gain in the
amplification stages of locating device 32. When V (GAIN) is at its maximum
level, locating device 32 is most sensitive and can receive even relatively weak
second signals 26. The signal received by antenna 74 is amplified at
amplification stage 76 and then passed through the 216-220 megahertz filter of
harmonic filter/amplification stage 78. The filtered output of stage 78 is then
summed with the output of signal processing section 82 at summing junction 80
and passed through the 10.7 megahertz bandpass filter included in the
filter/amplification stage 90. The output of stage 90 is combined with the
output of voltage controlled oscillator 84.
The output frequency of
voltage controlled oscillator 84 can be adjusted by adjusting frequency control
potentiometer 86. The range of adjustment, in an exemplary embodiment, is plus
or minus 5 kilohertz. This adjustment permits fine tuning of the receiver to
compensate for frequency drift of transmitter 52 and the internal oscillators of
locating device 32.
The output of summing junction 88 is then passed
through a 455 kilohertz bandpass filter and amplified at filter/amplification
stage 92. This filtered signal is combined with the output of the 455 kilohertz
reference oscillator 96 at summing junction 94. The resultant signal is
amplified at amplifier 98 and passed through filter/amplification stages 100,
102. The final output of this receiver portion of locating device 32 excites
speaker 108 which emits an audible 1 kilohertz peak tone. After the signal is
passed through detector 106, it is provided as an input to meter 110. Meter 110
provides a visual indication of the signal strength and could be analog or
digital, having various configurations. As is commonly employed in this and
related fields of art, the visual feedback provided by the meter assists the
operator in aiming portable locating device 32 to further pinpoint the position
of animal 22. When locating device 32 is pointed directly at animal 22, the
position of the needle on meter 110 will correspond to maximum signal strength.
Portable locating device 32 can be operated at night or under low light
conditions by switching on switch 124, thereby causing microcontroller 72 to
excite the back light LED 112 which emits light to illuminate the face of meter
110. Additionally, the operator can receive audible feedback on the position of
animal 22 by using headphones which are plugged into external headphone jack
104.
As owner 28 becomes nearer and nearer animal 22, the strength of
second signal 26 transmitted by transceiver 12 increases. Owner 28 can decrease
the gain of the amplification stages in portable locating device 32 using signal
attenuator 120 to maintain the received signal within the operating range of the
receiver. Eventually, owner 28 will establish visual contact with animal 22.
Once animal 22 is recovered, transceiver 12 can be deactivated by bringing
transceiver 12 within zone 18 or otherwise providing a first signal 16.
Alternatively, a mast-mounted, long range locator receiver 34 may be
used to receive second signal 26 and provide information regarding the
approximate location of animal 22. Locator receiver 34 is essentially the same
receiver circuit as hand-held receiver 32. The large, mast-mounted antenna,
which typically rotates 360.degree. on a tower, replaces antenna 74 of hand-held
receiver 32. While the hand-held receiver may have a range of 8-10 miles, a
mast-mounted receiver may have a range of 50-60 miles.
In an alternate
embodiment of the present invention, a display/programming unit 151 includes a
microcontroller 150, a display 152, an audible alarm 154, and a keyboard 156, as
shown in FIG. 5. Microcontroller 150 may be a standard, programmable
microcontroller, such as a MC68HC705J1A. Using common programming practices,
keyboard 156 and display 152, which may be a 20 character, two line, liquid
crystal display, microcontroller 150 may be programmed to provide a particular
first signal 16 to transceiver 12 which programs logic unit 50 such that logic
unit 50 generates a second signal 26 which is encoded with information that
identifies that particular transceiver 12 (i.e., an ID signal).
Display/programming unit 151 is connected to hand-held receiver 32 to identify
the particular second signal 26 corresponding to a particular collar.
Display/programming unit 151 is connected to external headphone jack 104 of
hand-held receiver 32 which supplies display/programming unit 151 with the
demodulated audio signal from transceiver 12. Once transceiver 12 is programmed
to supply the proper ID signal (i.e., second signal 26), and the
display/programming unit 151 is connected to receiver 32, then display 152
provides substantially positive electronic identification of the animal 22
wearing a particular transceiver 12.
Transceiver 12 would be programmed
before initial operation according to the above-described procedure. As
explained above, transceiver 12 remains in a standby mode until it receives an
initial first signal 16 from base unit 12. Once this first reset signal is
received, transceiver 12 begins normal functioning. When transceiver 12 enters
an active mode, it emits a second signal 26 which identifies the animal 22.
In addition to programming transceivers 12 with electronic
identification information, display/programming unit 151 of this embodiment may
be used to program transceivers 12 with predetermined time period data
corresponding to a particular animal. Thus, if an animal's behavioral patterns
change, or if a collar 20 is worn by a different animal, the operator may
program transceiver 12 with a predetermined time (i.e., activation time limit)
corresponding to the present behavioral patterns of the animal.
While
the present invention has been described as a locator system for use with
animals, and more particularly, house pets, it is to be understood that the
general principles disclosed herein are readily applicable to other situations
wherein it is desirable to detect the absence of a "movable object" and to
locate the object once it is determined to be absent. For example, the present
invention could readily be used to track the location of humans such as
prisoners, vehicles such as rental cars, and objects such as books in a library.
While this invention has been described as having exemplary embodiments,
this application is intended to cover any variations, uses, or adaptions using
its general principles. Further, this application is intended to cover such
departures from the present disclosure as come within the known or customary
practice within the art to which it pertains. The spirit and scope of the
invention are to be limited only by the terms of the appended claims.
* * * * *