FIELD OF INVENTION

The present invention provides a system for monitoriηg a person, or persons, to determine if they remain within a preselected distance from a base-station and for locating their position should they move or be moved outside the preselected distance from the base-station.

BACKGROUND OF THE INVENTION

Conventional means for locating persons, animals or moving objects often utilize a radio transmitter adapted to be worn by the person cr mounted in the movable object, such as a vehicle, which is activated by receipt of an emergency signal containing a unique address code for the radio transmitter. Once activated by a signal or automatically after the passage of a period of time, the radio transmitter sends out a homing signal. The homing signal is then tracked by radio direction finding and distance measuring equipment which indicates the transmitter's direction and distance.

Some locating devices contain "patch-through" systems, whereby a mobile transceiver communicates with complex location finding beacons. The beacons process the transmitted signals to determine and, subsequently, to transmit the precise location of the object to the remote base-station.

Still other devices utilize a transmitting device, attached to a person confined to a specific location, e.g., a person on probatio 'or house arrest. The transmitting device generates signals to a base-station, such as a police station, when the person ovεs outside the specified location. However, the communication in these devices is usually one-way, i.e., from the transmitting device to the base-station. Since the transmitting device may not receive a signal from the base-staticn, it may not alert the person on whom it is

placed that that person has moved outside the specifie _d location.

Another locating device operates by continuously determining the position of an object relative to a predetermined acceptable route between two points and generating an exception report upon the object's movement outside of that route. The exception report is then transmitted to a remote central dispatcher. One disadvantage of this approach is that there is no indication to the user of their position outside the acceptable route so that the user may return the object to the acceptable route.

Thus, conventional devices for monitoring and locating people or objects present several disadvantages. They do not provide for: continuous monitoring, automatic warning to both an observer, such as a parent, and to the people being observed, such as children, that one or more of the children has moved beyond the preselected distance from a base-station, automatic generation of homing signal or signals if the child or children do not return within the preselected distance within a preselected delay period, automatic indication to the parent that the child or children have remained beyond the preselected distance for longer than the preselected delay period, continuous locating of the child or children based on the detection of homing signals, and automatic resumption of continuous monitoring of the child or children which return within the preselected distance from the base-station.

SUMMARY OF THE INVEN ION

The present invention provides a system for monitoring, children, for example, other persons or objects to determine if they remain within a preselected distance from a base-station, and for locating their position should they move or be moved outside the preselected distance from the base-station.

An advantage of the present invention is combining the monitoring and locating functions: to continuously determine whether the children are within or outside of the preselected area; to indicate to both the person using the invention and the children that the children are outside the preselected area during a warning period and for a period greater than the warning period; and to allow the person using the invention to determine the precise location of the children after the children move outside of the preselected area.

Another advantage of the present -invention is the automatic resumption of either the monitoring or ^' locating functions after- the children move within or outside of the preselected area, respectively. In this way, the present invention automatically reestablishes the monitoring function after operating in the locating function v/hen the children relocate themselves within the preselected distance.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a functional block diagram showing the basic operation of a representative embodiment according to the present invention when the base-station is operating in a monitoring function;

Figure 2 is an illustration of a base-station unit of the representative embodiment according to the present invention;

Figure 3 is an illustration of a fixed stand for the base-station unit of the representative embodiment according'to the present invention;

Figure 4 is an illustration of a transceiver unit of the representative embodiment according to the present invention;

Figure 5 is a functional block diagram showing the basic operation of a representative embodiment according to the present invention when the transceiver unit is moved to a location outside of the preselected area; and

Figure 6 is a functional block diagram showing the basic operation of a representative embodiment according to the present invention v/hen the base-station is operating in a locating function after the transceiver unit is moved to a location outside of the preselected area.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 is a functional block diagram showing the basic operation of a representative embodiment according to the present invention v/hen the base-station is operating in a monitoring function. The monitoring and locating system of the representative embodiment according to the present invention, indicated generally at l, shows a preselected area 10, a base-station unit 12, one or more transceiver units, for example, transceiver units 30A, 303, 0C, a base-station unit user 11, transceiver unit users 31A, 313, 31C, e.g., children, interrogation signals 14A, 14B, 14C, and return signals ISA, 15B, 15C.

Figure 2 is an enlarged view of the base-station unit 12 shown in Figure l. Figure 2 shows a custom set button 16, an option button 17, a base-station-receiving component 18, a base-station-transmitting component 19, a base-station antenna 22, an auditory means 50, transceiver indicators 28A, 28B, 28C, and a location indicator 29.

Figure 3 is an illustration of a fixed stand 21 for the base-station unit 12 of the representative embodiment according to the present invention, and shows the base- station unit 12 and the transceiver units 30A, 30B, 30C docked in the fixed stand 21. In addition, Figure 3 shows the custom set button 16, the option button 17, the base-station-receiving component IS, the base-station-

transmitting component 19, the base-station antenna 22, the auditory means 50, the transceiver indicators 2SA, 28B, 23C, and the location indicator 29.

Figure 4 is an illustration of the transceiver unit 30C shown in Figure 1 and shows transceiver-transmitting component 32C, transceiver-receiving component 33C, voice-activated microphone 3 C, and one or more dipolar antennas 35A and 35B connected to the transceiver unit 30C.

Figure 5 is a functional block diagram showing the basic operation of a representative embodiment according to the present invention 1 when the transceiver unit 30C is moved to a location beyond the preselected distance 10. In addition, Figure 5 shows the base-station unit user 11, the base-station unit 12, the transceiver units 30A, 3OB, the transceiver unit users 31A, 313, 1C, the interrogation signal 14A, 1 B, 14C, and the return signals 15A, 15B.

Figure 6 is a functional block diagram showing the basic operation of a representative embodiment according to the present invention 1 when the base-station unit 12 is operating in a locating function after the expiration of a preselected delay period triggered at the base-station unit 12 when' he transceiver unit 30C is moved to a location beyond of the preselected distance 10. Figure 6 shows the base-station unit user 11, the transceiver units 30A, 0B, the transceiver unit users 1A, 3IB, 31C, the interrogation signal 1 , 14B, 14C, the return signals 15A, 15B, and the homing signal 15C.

In the overall operation of the present invention, a supervisor, babysitter, or parent, as the base-station unit user 11, may wish to ensure that one or more children 31A, 3IB, and 31C (as the one or more transceiver units users 31A, 31B, 31C) , remain within the preselected area 10, such as an area enclosing a backyard

or playground. The parent 11 can utilize the base- station unit 12, operating in the monitoring function, to continuously determine whether each of the children 31A, 3IB, 31C (wearing or controlling the transceiver units 30A, 3OB, 30C) are within the preselected area 10. Thus, the base-station unit 12 of the representative embodiment performs the monitoring function and the locating function for each one of the one or more transceiver units 30A, 30B, 30C.

In the event that one or more children 31A, 3IB, 31C travel and remain outside of the preselected distance 10, the base-station unit 12, operating in the locating function, sounds an alarm to alert the parent 11. The parent 11 may then utilize the base-station unit 12 to locate the position of each of the children who is outside of the preselected distance 10.

Moreover, if any of the children 1A, 3IB, 1C should return to the preselected distance 10 at any time, the base-station unit 12 can resume the monitoring function and cease the locating function. For example, if the base-station unit 12 is operating in the locating function for the transceiver unit 30A, it can cease operating in the locating function and return to the monitoring function when the transceiver unit user 1A moves the transceiver unit 30A within the preselected area 10.

In addition, with respect to those children that remain within the preselected distance 10, the base-station unit 12 can continues to operate in the locating function for those children. Thus, the monitoring and locating functions performed by the base-station unit 12 for each one of the transceiver units 30A, 30B, 30C, are independent of the other transceiver units 30A, 30B, 30C. For example, the base-station unit 12 can trigger the locating function for the transceiver unit 30C, while

remaining in the monitoring function for the other transceiver units 30A and 3OB.

As shown in Figure 2, the base-station unit 12 is a portable unit. Accordingly, the base-station unit 12 can operate while located in the fixed stand 21, or while removed from the fixed stand 21 and transported by the. base-station unit user 11. The base-station unit 12 is provided with a base-station antenna 22 for transmission of the interrogation signal 14C, and receipt of the return signal 15C and the homing signal 27C.

The base-station unit 12 may also be provided with means for selecting the preselected distance 10 from the base station, within which the transceiver unit 30C should remain. The means for selecting the preselected distance 10, in the representative embodiment, includes a switch or the option button 17 which can contain several settings corresponding to several preselected distances defining a distance from the base-station. For example, in the representative embodiment, the base-station unit user 11 can select a predetermined distance defining the area in the ranges of approximately 100, 200 or 300 feet from the base-station unit 12. The present invention 1 also contemplates setting the preselected area by moving the transceiver unit 30C to a location which defines the desired distance from the base station 12 and then activating a switch or the custom set button 16. In this way, the preselected distance 10 can be set to a precise area determined by the base-station unit user 11.

The base-station-transmitting component 19 generates and sends the interrogation signal 14C to the transceiver unit 30C. The interrogation signals 14A, 14B, and 14C, may be sent at many suitable frequency levels, however, in a preferred embodiment the frequency range of about 49.82 - to about 49.90 MHz is utilized. Additionally, the interrogation signals 14A, 14B, 14C, may contain u ique digitized coded inforr.aticn assigned exclusively

to the transceiver unit 30C and used to identify the transceiver unit 30C. Also, each one of the transceiver units 30A, 30B, and 30C can have unique digitized coded information for communication with the corresponding interrogation signals 14A, 14B, 14C.

The base-station unit user 11 can be alerted to the operation of the base-station unit 12 in the monitoring and locating functions for each of the transceiver units 30A, 3OB, and 30C. To indicate operation in the monitoring function, the base-station unit 12 can activate the transceiver indicators 28A, 2SB, 28C (one for each of the transceiver units 30A, 3OB, 30C) , located on the base-station unit 12, such as, for example, LEDs. Also, to indicate -operation in the locating function, the base-station unit 12 can deactivate the transceiver unit indicators 28A, 28B, 2SC.

The base-station unit 12, operating in the locating function, displays the strength of the homing signals

27A, 27B, 27C, generated by transceiver units 3CA, 3OB, and 30C on the location indicator 29, such as, for example, a set of LEDs. Thus, when the base-station unit 12 triggers the locating function for the transceiver units 30A, 30B, 30C, the base-station unit 12 can alert .the base-station unit user 11 by deactivating the transceiver unit indicators 28A, 28E, 2SC and by displaying the detection and strength of the homing signals 27A, 27B, 27C, on the location indicator 29. The present invention 1 may also include an independent locating function display for each one of the transceiver units 30A, 30B, 30C.

The components of the base-station unit 12 and the transceiver units 30A, 3OB, 30C may be selected from a wide variety of small transceivers, which are FCC approved as electronic radio frequency devices, and which are well known to those skilled in the art as suitable for this Durnose.

The transceiver unit 30C, may be contained in a belt buckle or can be mounted on a belt with the use of, for example, a belt engaging hook, a belt clip or an alternative means such as a small pouch or bag. Alternatively, the transceiver unit 30C can be placed within or mounted on some other article of clothing.

The transceiver unit 30C is provided with one or more dipolar antennas 35A and 353, for receipt of the interrogation signal 14C, and transmission of the return signal 15C and the homing signal 27C. The dipolar antennas 35A and 353 can be positioned, for example, in the belt, at one or more locations to facilitate communication and minimize interference. For example, two dipolar antennas 5A and 35B can be placed in the belt for mounting near the hips of the transceiver unit user 31C.

The transceiver units 30A, 30B, and 30C may also be provided with a voice activated microphone 34C and means for transmitting the voice signals in which case the base unit 12 is also provided with means for receiving the voice communication and a speaker 50.

The transceiver units 30A, 3OB, 30C may also be adapted to cease generating the return signal 15A, 15B and 15C if it should become immersed in water, for example, if a child falls into a pool or lake. Thus, the parent 11 is notified of this emergency even if the child remains within preselected distance 10.

The transceiver-receiving component 33C of the transceiver unit 30C detects the interrogation signal 14C, which can contain the digitized information corresponding to the transceiver unit 30C, sent by the base-station-transmitting component 19.

The transceiver-transmitting component 32C generates and sends the return signal ISC to the base-station-receiving

component 18 in response to the detection of the interrogation signal 14C by the transceiver-receiving component 33C. The return signal 15C may be sent in a ide range of frequencies, however, in a preferred embodiment the frequency range of about 49.82 to about 49.90 MH2 is utilized. The return signal 15c may be adapted to contain unique digitized coded information for communication with the corresponding interrogation signal 14C.

Alternatively, the transceiver-transmitting component 32C can generate and send the homing signal 27C to the base- station-receiving component IS. The homing signal 27C can, for example, in the representative embodiment, consist of a continuous wave signal at approximately 470 MHz. In addition, in the representative embodiment, the homing signal 2 C is not unique to each of the transceiver units 0A, OB, 30C. Accordingly, the location indicator 29, upon the base-station-receiving component 18 detecting the homing signals 27A, 27B, 27C, does not distinguish between the transceiver units 30A, 3OB, 30C, on the location indicator 29.

As shown in Figure 3, the fixed stand 21 for the base- station unit 12 may contain docking stations for holding the base-station unit 12 and the transceiver units 30A, 3OB and 30C. The fixed stand 21 can serve as a recharging station for both the base-station unit 12 and transceiver units 30A, 3OB, 30C. In addition, both the base-station unit 12 and the transceiver units 30A, 30B, and 30C can be battery operated, using either rechargeable or disposable batteries.

A detailed functional description of the present invention 1 is set forth below. The description is generally directed to the transceiver unit 30C since the present invention 1 operates in the same manner for each of the one or more transceiver units 30A, 30B, and 0C.

After the base-station unit 12 is energized and the preselected distance 10 is set, the base-station unit 12 begins operating in the monitoring function for each one of the transceiver units 30A, 30B, 30C. The base-station unit 12 can continue to operate in the monitoring function so long as, for example, the transceiver unit 30C remains within the preselected area 10 and is operable. Under these conditions, the base-station unit 12 generates and sends the interrogation signal 14C to the transceiver-receiving component 33C of transceiver unit 30C which, in turn, receives the interrogation signal 14C. In response, the transceiver-transmitting component 32C on the transceiver unit 30C generates and sends a return signal 15C. The base-station-receiving component 13 then receives the return signal 15C. The communication between the base-station unit 12 and the transceiver unit 30C can continuously proceed as follows under those conditions: the base-station-transmitting component IS sends the interrogation signal 14C, and the detection of the interrogation signal 14C by the transceiver-receiving component 33C, which corresponds to the digital component of the interrogation signal 14C, triggers the transceiver-transmitting component 32C to send the. eturn signal 15C to the base-staticn-receiving component 18.

However, the base-station unit 12 can trigger the locating function after a change in those conditions. More specifically, when both of two situations occur: First, either the transceiver unit 30C is moved outside of the preselected area or the transceiver unit 30C becomes inoperable; and second, the delay period, such as, for example, 16 seconds, which is triggered at the base-station unit 12 as a result of the first situation, expires, the base-station unit 12 can trigger the locating function.

Moreover, if the transceiver unit 30C is located outside the preselected area 10, the transceiver-receiving

component 33C does not detect the interrogation signal 14C because, based on the base-station unit user 11 setting the preselected area 10, the transceiver- receiving component 33C is set to receive the interrogation signal 14C only while the transceiver unit 30C remains within the preselected area 10. Since the transceiver-receiving component 3C is unable to detect the interrogation signal 14C sent by the base-station- transmitting component 19, it detects an interruption in the interrogation signal 14C and, as a result, ceases to respond with the return signal 15C.

In addition, the transceiver-transmitting component 32C can alert the transceiver unit user 1C that the transceiver unit 30C is outside of the preselected area 10, e.g., if the transceiver unit user 31C travels to a location outside of the preselected area 10, the transceiver unit 30C enters the mode in which the transceiver unit 30C warns the transceiver unit user 1C to return to a location within the preselected area 11. The warning may consist of a series of audible tones generated by auditory means 50. The audible signal tones serve as a warning to instruct the transceiver unit user 31C to return to the preselected distance 10 from the base-station 12.

If the transceiver unit user 31C does not return to a location inside the preselected area 10 within the delay period, which is triggered at the transceiver unit 30C, the transceiver unit 30C enters a mode in which the transceiver-transmitting component 2C sends out the homing signal 27C. The delay period can be, in a representative embodiment, approximately 16 seconds. At the end of the delay period, if the transceiver unit user 31C has not returned to a location within the preselected area 10, the transceiver unit 30C will trigger the transceiver-transmitting component 32C to send the homing signal 27C.

Additionally, if the transceiver unit 30C malfunctions or is rendered inoperable, the transceiver-transmitting component 32C ceases operation and cannot send the return signal 15C. This may occur, for example, when a child, as the transceiver unit user 1C, falls into a pool, thereby disabling the transceiver unit 30C's electrical hardware, or, as another example, when the batteries of one of the transceiver units 30A, 3OB, 30C expire.

In the absence of any of these situations which, in the representative embodiment, cause the transceiver- receiving component 33C to cease sending the return signal 15C, the. base-station unit 12 can continue to operate in the monitoring function.

Once the base-station unit 12 triggers the locating function, the base-station unit 12 operates to locate the transceiver unit 30C from which the transceiver- transmitting component 32C generates and sends the homing signal 27C. The range of the base-station unit 12 operating in the locating function may be affected by structures such as, bridges, water and electrical towers, homes, other radio frequency devices being operated in the vicinity, and unusual atmospheric conditions, however under ideal conditions a range of approximately 10-12 miles can be expected.

The base-station unit 12 includes direction finding circuitry for operating in the locating function for receiving the homing signal 27C via base-station receiving component 18. This circuitry can indicate the direction of the transceiver unit 0C, and, thus, the location of the transceiver unit user 31C. As the base- station unit user 11 points the base-station unit 12 in various directions, the base-station unit 12 can display the strength of the homing signal 27C received from each of the various directions on the location indicator 29. By indicating to the base-station unit user 11 the direction from which the strenσth of the ho inα siσnai

29824 PCT/US94/06355

27C is the strongest, the base-station unit 12 allows the base-station unit user 11 to locate the transceiver unit 30C.

In addition, if the base-station unit 12 triggers the locating function with respect to more than one of the transceiver units 30A, 30B, and 30C, the detection and strength of the homing signals 27A, 27B, and 27C, from any of the transceiver units 30A, 30E, and 30C is displayed on the location indicator 29.

when the transceiver unit user 31C travels beyond the preselected distance 11, the base-station unit 12, although operating in the locating function, continues to send out the interrogation signal 14C. Thus, if the transceiver unit 30C is moved to a location within the preselected distance 10 after the base-station unit 12 is operating in the locating function, the transceiver- receiving component 33C continues to detect the interrogation signal 14C, and the transceiver- transmitting component 32C responds by generating the return signal 15C. The ba≤e-station-receiving component 18 then detects the return signal 15C and reestablishes the monitoring function for the transceiver unit 30C.

The transceiver units 30A, 3OB, and 30C can also contain a voice-activated microphone, for example 34C, in the transceiver unit 30C, which in a preferred embodiment transmits, in the 49.82 - 49.90 MHz frequency range.

The present invention 1 contemplates the use of an adapter for an AC power source. Using this function, it is further contemplated that the present invention 1 may be used, for example, to monitor the transceiver unit user 31C, who may be an infant in a crib, at a location remote from the base-station unit 12.