Abstract:
A tracking device, a related combat simulator, and methods for their use. The tracking device comprises a SPS receiver, a communications interface for reversibly mounting therein a communications card, a combat simulation device interface, and a control unit for receiving location data from the SPS receiver, for transmitting the location data via the communications interface, and for exchanging combat simulation data between the combat simulation device interface and the communications interface. The combat simulator includes a control center for controlling several tracking devices. For civilian applications, the combat simulation device interface is replaced with an alarm button.

Description:
FIELD AND BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to tracking devices and systems and, more particularly, to a tracking device, and a system based on these devices, for monitoring the movements of subjects. In military applications of the present invention, the subjects are participants in simulated combat.  
           [0002]    Modern armies use laser-based combat simulation devices for training purposes, to preclude the expense and danger of using live ammunition. For example, such devices are used in the U.S. Army&#39;s MILES (Multiple Integrated Laser Engagement System) 2000 and by the U.S. Army&#39;s MILES 3 system. Each participant in a training exercise that uses the MILES 2000 system is provided with a combat simulation device that includes a simulated weapon and a target sensor. The simulated weapon includes an infrared laser that is fired by the participant, acting as an aggressor, at other participants. The target sensor is an infrared sensor that registers hits by laser beams of other participants. The lasers and the target sensors are tuned so that the signals provided by the target sensors are representative of the damage that real weapons would inflict on real targets. Whenever a laser is fired, and whenever a target sensor is hit, corresponding signals are transmitted to a control center to provide the control center with data relating to the simulated combat effectiveness of the participants. Note that the participants may be individual soldiers or combat vehicles or a mixture of both. In addition, whenever a target sensor is hit, that target sensor activates an effects simulation system on the target that produces a special effect indicative of the hit. For example, an effects simulation system on a tank may set off a pyrotechnic device.  
           [0003]    One limitation of prior art systems such as MILES 2000 is that the transceivers used by the participants and by the control center are military transceivers that are specific to their respective armies. This limits the interoperability of these systems for joint training exercises of allied armies.  
           [0004]    There is thus a widely recognized need for, and it would be highly advantageous to have, a combat simulation system that allows interoperability among several allied armies. As will be seen below, such a system, suitably modified, would also have important civilian applications.  
         SUMMARY OF THE INVENTION  
         [0005]    According to the present invention there is provided a tracking device, including: (a) a SPS receiver; (b) a communications interface for reversibly mounting therein a communications card; (c) a combat simulation device interface; and (d) a control unit for receiving location data from the SPS receiver, for transmitting the location data via the communications interface, and for exchanging combat simulation data between the combat simulation device interface and the communications interface.  
           [0006]    According to the present invention there is provided a combat simulation system including: (a) a control center including: (i) a control center communications interface for reversibly mounting therein a control center communications card that operates according to a communications protocol, and (ii) a control center transceiver, operationally connected to the control center communications interface; and (b) a plurality of tracking devices, each tracking device including: (i) a combat simulation device interface, (ii) a SPS receiver, (iii) a tracking device communications interface for reversibly mounting therein a tracking device communications card that operates according to the communications protocol, (iv) a tracking device transceiver, operationally connected to the tracking device communications interface, for transmitting transmitted signals to the control center and receiving received signals from the control center via the control center transceiver, and (v) a control unit for: (A) receiving location data from the SPS receiver, (B) transmitting the location data to the control center via the tracking device transceiver and the control center transceiver, and (C) exchanging combat simulation data between the combat simulation device interface and the control center, via the tracking device transceiver and the control center transceiver, the data being transmitted and received by the transceivers as the signals.  
           [0007]    According to the present invention there is provided a tracking device, including: (a)a SPS receiver; (b)a communications interface for reversibly mounting therein a communication card; (c) a personal sensor; and (d) a control unit for receiving location data from the SPS unit, for receiving personal status data from the personal sensor, and for transmitting the data via the communications interface.  
           [0008]    According to the present invention there is provided a tracking device, including: (a) a SPS receiver; (b) a communications interface for reversibly mounting therein a communication card; (c) an alarm button for activating a transmission of an alarm signal via the communications interface; and (d) a control unit for receiving location data from the SPS unit, for transmitting the data via the communications interface, and for including at least a portion of the location data in the alarm signal.  
           [0009]    According to the present invention there is provided a personal tracking system including: (a) a control center including: (i) a control center communications interface for reversibly mounting therein a control center communications card that operates according to a communications protocol, and (ii) a receiver, operationally connected to the control center communications interface; and (b) a plurality of tracking devices, each tracking device including: (i) a SPS receiver, (ii) a tracking device communications interface for reversibly mounting therein a tracking device communications card that operates according to the communications protocol, (iii) a personal sensor; (iv) a transmitter, operationally connected to the tracking device communications interface, for transmitting signals to the control center via the receiver, and (v) a control unit for: (A) receiving location data from the SPS receiver, (B) receiving personal status data from the personal sensor, and (C) transmitting the data to the control center via the transmitter and the receiver, the data being transmitted by the transmitter and received by the receiver as the signals.  
           [0010]    According to the present invention there is provided a personal tracking system including: (a) a control center including: (i) a control center communications interface for reversibly mounting therein a control center communications card that operates according to a communications protocol, and (ii) a receiver, operationally connected to the control center communications interface; and (b) a plurality of tracking devices, each tracking device including: (i) a SPS receiver, (ii) a tracking device communications interface for reversibly mounting therein a tracking device communications card that operates according to the communications protocol, (iii) a transmitter, operationally connected to the tracking device communications interface, for transmitting signals to the control center via the receiver, one of the signals being an alarm signal, (iv) an alarm button for activating a transmission of the alarm signal, and (v) a control unit for receiving location data from the SPS receiver, for transmitting the data to the control center via the transmitter and the receiver, the data being transmitted by the transmitter and received by the receiver as the signals, and for including at least a portion of the location data in the alarm signal.  
           [0011]    According to the present invention there is provided a method of simulating combat between an aggressor participant and a defender participant, including the steps of: (a) providing each participant with a tracking device including: (i) a SPS receiver; and (ii) a communications interface for reversibly mounting therein a communications card, both the communications cards operating according to a common communications protocol; (b) providing each participant with a combat simulation device operationally coupled to the tracking device of the each participant; (c) providing a control center for coordinating the simulated combat; (d) simulating an attack by the aggressor participant against the defender participant, using respective the combat simulation devices, the simulating including the steps of: (i) for each participant, determining a location of the each participant, using the respective SPS receiver, and (ii) for each participant, transmitting data related to the attack to the control center via the respective communications interface, the data of each participant including the respective location.  
           [0012]    According to the present invention there is provided a method of monitoring a location and a condition of a subject, including the steps of: (a) providing the subject with a tracking device including: (i) a SPS receiver, (ii) a communications interface for reversibly mounting therein a communications card, and (iii) a condition sensor for sensing a value of a physiological parameter of the subject; (b) providing a control center; (c) periodically sensing the value, by the tracking device, using the condition sensor; and (d) if the value is outside a predetermined range: (i) determining the location of the subject, by the tracking device, using the SPS receiver, and (ii) transmitting, to the control center, by the tracking device, via the communications interface, an indication of the location and of the value.  
           [0013]    According to the present invention there is provided a method of monitoring a location of a subject, including the steps of: (a) providing the subject with a tracking device including: (i) a SPS receiver, and (ii) a communications interface for reversibly mounting therein a communications card; (b) providing a control center; and (c) activating the tracking device, by the subject, to: (i) determine the location of the subject, using the SPS receiver, and (ii) transmit the location to the control center, via the communications interface.  
           [0014]    The tracking devices and the control center of the present invention provides the desired interoperability by relying on civilian communications networks for communicating with each other. A military tracking device of the present invention includes an interface to a combat simulation device, a Satellite Positioning System (SPS) receiver for determining the participants location on demand, and a communications unit. The communications unit includes a transceiver, a communications card that enables the communications unit to operate according to a local civilian communications protocol, and an interface into which the communications card is reversibly inserted. Typically, the interface to the communications card is either a PCMCIA interface or a serial (e.g., RS232) interface. Thus, the present invention is modular: the communications interface allows the use of different communications cards in different geographical locations. For example, a preferred embodiment of the tracking device of the present invention includes communications cards that operate according to the CDMA IS-95 protocol used for voice and data cellular telephony in North America, the GSM protocol used for cellular telephony in Europe and Asia (most preferably using the General Packet Radio Service (GPRS)), the CDPD protocol used for mobile radio communications and cellular telephony in North America and Israel, and the TETRA protocol used for mobile radio communications in Europe. The control center is equipped similarly with a transceiver, a communications card that enables the control center to communicate with the tracking devices according to the local civilian communications protocol via the corresponding local civilian communications network, and a communications interface into which the control center&#39;s communications card is reversibly inserted. Each tracking device also includes a control unit for receiving data from the SPS receiver and for exchanging data with the communications interface.  
           [0015]    When a combat simulation system of the present invention is taken from one region that uses one civilian communications protocol, to another region that uses a different civilian communications protocol, for example from North America to Europe, all that is needed to modify the system is to exchange the communications cards of the old region for the communications cards of the new region.  
           [0016]    The preferred SPS receiver of the present invention is a GPS receiver, although the scope of the present invention includes other SPS receivers, for example GLONASS receivers.  
           [0017]    When a participant acting as an aggressor fires its simulated weapon, or when the target sensor of a participant senses a hit by an aggressor&#39;s laser beam, signals indicative of these events are transmitted by the transceivers of the respective tracking devices to the control center, via the local civilian communications network and the control center transceiver. These signals include geographical coordinates and time stamps obtained from the SPS receivers of the respective tracking devices. The control center transmits control signals to the participants as needed, using its own transceiver, also via the local civilian communications network and the participants&#39; transceivers. Examples of these control signals include an indication to a participant that it has fired its laser as often as allowed and so is “out of ammunition”, and an indication to a participant that it has suffered severe enough hits to put it out of action. “Exchange” of such signals between a tracking device and the control center is understood herein to refer both to the transmission of signals from the tracking device to the control center, with receipt of the signals by the control center, and the transmission of signals from the control center to the tracking device, with receipt of the signals by the tracking device. Similarly, the “exchange” of data between the control unit of a tracking device and the communications interface of the tracking device is understood herein to refer both to the formatting of data by the control unit for transmission to the communication interface and the transmission of these data to the communication interface for transmission by the transceiver as transmitted signals according to the relevant communications protocol, and to the reception of data by the control unit from the communications interface as the communications interface receives these data consequent to the receipt of corresponding signals by the transceiver.  
           [0018]    Preferably, the formatting of data for transmission by the control unit includes compression of the data. Correspondingly, the receipt of data by the control unit from the communications interface includes decompression of the received data.  
           [0019]    Periodically, each tracking unit determines its location, using the SPS receiver, independent of any activity of the combat simulation device, and transmits that location to the control center. This allows the control center to tell when a participant enters an area that is off-limits (illegal) and to transmit a corresponding signal to the trespassing participant.  
           [0020]    Preferably, a tracking device of the present invention for personal use includes a personal sensor, such as a pulse rate sensor or a thermometer, for monitoring a physiological status of the participant. When data received by the control unit from the personal sensor indicate that the value of the corresponding physiological parameter of the participant is outside the normal range of that parameter, the control unit transmits a corresponding warning signal to the control center. This warning signal includes the location of the participant, as determined using the SPS receiver. Similarly, a preferred embodiment of the tracking device of the present invention includes an alarm button that allows the participant itself to activate the transmission of a similar alarm when the participant perceives itself to be in danger.  
           [0021]    Preferably, the control unit of a tracking device of the present invention includes a memory for storing copies of the simulated combat event data that are transmitted to the control center and that are received from the control center.  
           [0022]    A civilian tracking device of the present invention lacks an interface to a combat simulation device. In all other respects, the civilian tracking device of the present invention is identical to the military tracking device of the present invention, and the civilian control center of the present invention is identical to the military control center of the present invention. Those skilled in the art will be able to envision many civilian applications of the present invention. These include:  
           [0023]    locating lost children in an amusement park, with the control center being located at the amusement park office. Each visitor to the amusement park is provided with a vest, belt or holster that contains a civilian tracking device of the present invention.  
           [0024]    monitoring the condition of livestock on the open range, with the control center being located at ranch headquarters. Each animal is provided with a harness that contains a civilian tracking device of the present invention.  
           [0025]    Because the person or animal who is provided with the civilian tracking device of the present invention is not competing with another person or animal, this person or animal is referred to herein as a “subject” rather than a “participant”. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]    The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:  
         [0027]    [0027]FIG. 1 is a schematic block diagram of a tracking device of the present invention;  
         [0028]    [0028]FIG. 2 is a schematic illustration of a combat simulation system of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    The present invention is of a tracking device, and an associated tracking system, which can be used to track the locations and conditions of subjects such as people, vehicles and livestock. Specifically, in a military application thereof, the present invention can be used to enhance simulated combat, and in a civilian application thereof, the present invention can be used to locate missing persons and animals and to identify and locate persons and animals in distress.  
         [0030]    The principles and operation of a tracking device and system according to the present invention may be better understood with reference to the drawings and the accompanying description. More specifically, the present invention is described below with reference to its primary military application, simulated combat. It will be clear to those skilled in the art how to apply the principles of the present invention to its civilian applications.  
         [0031]    Referring now to the drawings, FIG. 1 is a schematic block diagram of a tracking device  10  of the present invention. The heart of tracking device  10  is a control unit  28 . Operationally connected to control unit  28  are a SPS receiver  12  (specifically, a GPS receiver), an interface  14  to a combat simulation device  16  (specifically a MILES 2000), an interface  18  to a communications card  20 , a transceiver  22 , a physiological sensor  30 , a speaker  31 , an alarm button  32  and a power supply  36 . Interface  18  is such that communications card  20  may be removed therefrom and replaced with a different communications card  20 . Usually, tracking device  10  comes with several communications cards  20 , each one specific to a different communications protocol. Four such communications cards  20  are shown in FIG. 1: a communications card  20  that operates according to the CDPD protocol, a communications card  20  that operates according to the CDMA I-95 protocol, a communications card  20  that operates according to the GSM protocol and a communications card  20  that operates according to the TETRA protocol. Communications card  20  that operates according to the GSM protocol is shown mounted in interface  18 . Suitable commercially available communications cards  20  include the AirCard  210  series, available from Sierra Wireless Inc. If Vancouver, British Columbia, Canada. Most preferably, interface  14 , like interface  18 , is such that combat simulation device  16  may be removed therefrom and replaced with a different combat simulation device.  
         [0032]    Most preferably, GPS receiver  12  is a differential GPS receiver.  
         [0033]    Transceiver  22  includes both transmit functionality  24  and receive functionality  26 . Transceiver  22  operates, under the control of control unit  28  and communications card  20 , to transmit data provided by control unit  28  as signals according to the specific communications protocol of communications card  20 , and to receive signals, according to the specific communications protocol of, that are interpreted as input data for control unit  28 .  
         [0034]    Control unit  28  exchanges combat simulation data with combat simulation device  16  via interface  14 . Control unit  28  also receives input data from GPS receiver  12 , sensor  30  and alarm button  32 . The input data from GPS receiver  12  are data indicating the location of tracking device  10 . Because the simultaneous equations solved by GPS receiver  12  include, as one of the unknowns thereof, the bias of the internal clock of GPS receiver  12  relative to the time kept by the GPS system, the input data from GPS receiver  12  also include a timestamp indicating the time when tracking device  10  was determined to be at that location. The input data from sensor  30  are values of a physiological parameter of a user of tracking device  10 . Preferred examples of sensor  30  include a pulse rate sensor and a thermometer. The input datum from alarm button  32  is an activation signal, as described below.  
         [0035]    Control unit  28  also includes a memory  34  for recording simulated combat events, as illustrated below.  
         [0036]    Control unit  28  and transceiver  22  are powered by a power module  36 . Power module  36  includes two rechargeable batteries  38  and  39 , and an interface  40  to a  12  volt vehicular DC power supply. Primary battery  38  is replaceable ,and powers tracking device  10  during normal use. Secondary battery  39  is installed permanently in power module  36  and is kept charged by primary battery  38 . The main function of secondary battery  39  is to preserve the data stored in memory  34  while tracking device  10  is turned off.  
         [0037]    Tracking device  10 , as illustrated in FIG. 1, can be used by a participant who is either a person or a vehicle. When mounted on a vehicle, tracking device  10  obtains power via interface  40 . When carried by a person, tracking device  10  obtains power from battery  38 . Physiological sensor  30  is specific to a participant who is a person; but it will be appreciated that a sensor appropriate to a vehicle could be substituted for physiological sensor  30 .  
         [0038]    [0038]FIG. 2 illustrates, schematically, a combat simulation system of the present invention. The combat simulation system includes, in addition to a plurality of tracking devices  10 , a control center  50  that exchanges signals with tracking devices  10 . Control center  50  includes an interface  52  to a communications card. Like interface  18 , interface  52  is such that a communications card may be removed therefrom and replaced with a different communications card. Indeed, the communications cards that are mounted reversibly in interface  52  is identical to the communications cards that are mounted reversibly in interfaces  18  of tracking devices  10 . Therefore, the communications card in FIG. 2 is designated by the same reference numeral  20  as is used to designate the communications card of tracking device  10  in FIG. 1. Operationally connected to interface  52  is a transceiver  54  that includes both transmit functionality  56  and receive functionality  58 . Note that only the components of control center  50  that are germane to an explanation of the present invention are depicted in FIG. 2. For example, control center  50  necessarily includes a control unit and a power supply, neither of which are shown in FIG. 2.  
         [0039]    Most preferably, if communication between control center  50  and tracking devices  10  is via a civilian cellular telephony network, control center  50  also includes a landline connecting interface  52  to the civilian network. This reduces the wireless traffic burden on the civilian network consequent to the operation of the present invention.  
         [0040]    Also shown in FIG. 2 are two participants  42  in simulated combat. Each participant  42  is equipped with a respective tracking device  10 . Some components of tracking devices  10  are illustrated separately: simulated weapon  44 , a part of combat simulation device  16  of tracking device  10   a;  target sensor  46 , a part of combat simulation device  16  of tracking device  10   b;  and physiological sensor  30  of tracking device  10   b.  Sensor  30  is a pulse rate sensor, mounted in close proximity to the left femoral pulse of participant  42   b.  Tracking devices  10   a  and  10   b  communicate with control center  50  via base transceiver stations (BTSs)  60  of a cellular telephony network that operates according to the GSM communications protocol. Consequently, communications cards  20  of tracking devices  10   a  and  10   b  and of control center  50  all operate according to the GSM communications protocol.  
         [0041]    A secondary function of secondary battery  39  of tracking device  10  is to power the transmission of a “shutoff” message from tracking device  10  to control center  50  when tracking device  10  is turned off.  
         [0042]    Also shown in FIG. 2 are two satellites  62  of the GPS constellation. GPS receivers  12  of tracking devices  10  determine their locations based on signals received from satellites  62 . If GPS receivers  12  are differential receivers, control center  50  sends differential correction data to tracking devices  10 , using a standard protocol such as the NEMA protocol. GPS receivers  12  use this differential correction data, as is well-known in the art, to account for the ≈50 meter error that is included by the U.S. Department of Defense in the civilian signals transmitted by satellites  62 , so that the locations determined by GPS receivers  12  are accurate to within about one meter.  
         [0043]    In the specific scenario illustrated in FIG. 2, participant  42   a  fires simulated weapon  44  at participant  42   b . A laser beam  48  from simulated weapon  44  hits target sensor  46 . Both the firing of simulated weapon  44  and the sensing by target sensor  46  of the impact thereon of laser beam  48  are simulated combat events. Control unit  28  of tracking device  10   a  formulates a message that embodies the event of the firing of simulated weapon  44 . This message includes the geographical coordinates of participant  42   a  and a time stamp, both obtained from GPS receiver  12  of tracking device  10   a . Control unit  28  of tracking device  10   a  stores this message in memory  34  of tracking device  10   a  and also transmits this message to control center  50 . Similarly, control unit  28  of tracking device  10   b  formulates a message that embodies the event of the sensing by target sensor  46  of the impact thereon of laser beam  48 . This message includes the geographical coordinates of participant  42   b  and a time stamp, both obtained from GPS receiver  12  of tracking device  10   b . Control unit  28  of tracking device  10   b  stores this message in memory  34  of tracking device  10   b  and also transmits this message to control center  50 .  
         [0044]    In response to the messages received from participants  42 , control center  50  sends messages of its own to participants  42 . Control center  50  sends a message to participant  42   b , via tracking device  10   b , that, because of the direct hit of laser beam  48  on target sensor  46 , participant  42   b  is “dead” and must stop participating. Meanwhile, participant  42   a  has fired simulated weapon  44  a number of times equal to the number of rounds of ammunition that participant  42   a  would carry into combat. Therefore, control center  50  sends a message, to tracking device  10   a  and to participant  42   a , that disables simulated weapon  44  and that informs participant  42   a  that participant  42   a  is “out of ammunition”. These two messages from control center  50  also are recorded in memories  34  of their respective tracking devices  10 .  
         [0045]    Periodically, tracking devices  10   a  and  10   b  send tracking messages to control center  50 . A tracking message includes geographical coordinates and a timestamp from GPS receiver  12 , and also a value of a physiological parameter from sensor  30 . If the geographical coordinates of a participant  42  indicates that that participant  42  is in an illegal location, control center  50  sends that participant  42  a message, via speaker  31 , indicating that that participant  42  has trespassed and must return to a legal location. If the received value of the physiological parameter of a participant  42  is outside a predetermined normal range, indicating that that participant is in distress, control center  50  initiates emergency action. A distress message also may be initiated by a participant  42 , by pushing alarm button  32 . Pushing alarm button  32  activates the transmission of a distress message from tracking device  10  to control center  50 . Like the routine tracking messages, this distress message includes geographical coordinates and a timestamp from GPS receiver  12 . Upon receipt of a distress message, control center  50  initiates emergency action.  
         [0046]    In addition to including the values of the physiological parameter in the tracking messages, control unit  28  also monitors these values itself. If the values start to fall outside the predetermined normal range, control unit  28  sounds an alarm, using speaker  31 , to indicate to participant  42  that participant  42  must take corrective action.  
         [0047]    GPS receiver  12  must have a clear line of sight to at least four satellites  62  in order to obtain a location fix. In cluttered environments, GPS receiver  12  may have a clear line of sight to only three or fewer satellites  62 . In such a case, control unit  28  uses one of several known methods for using signals from both satellites  62  and BTSs  60  to obtain a location fix. See for example U.S. Pat. No. 5,945,944 to Krasner, U.S. Pat. No. 5,999,124 to Sheynblatt, International Patent Application WO99/61934 to Camp, and U.S. Pat. No. 5,982,324 to Watters et al. All four of these documents are incorporated by reference for all purposes as if fully set forth herein.  
         [0048]    While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.