WO2009151713A2

WO2009151713A2 - Systems and methods for communicating a firearm discharge event

Info

Publication number: WO2009151713A2
Application number: PCT/US2009/038020
Authority: WO
Inventors: Darryl P. Nelson
Original assignee: Raytheon Company
Priority date: 2008-03-25
Filing date: 2009-03-24
Publication date: 2009-12-17
Also published as: WO2009151713A3

Abstract

According to one embodiment, a system for communicating a discharge event of a firearm (16) includes a discharge sensor (14) mechanically coupled to the firearm (16). The discharge sensor (14) is operable to generate a discharge signal in response to a discharge event of the firearm. The system also includes a first node (12) in a communications network (10). The first node (12) is mechanically coupled to the firearm (16) and is in communication with the discharge sensor (14). The first node (12) is also operable to receive the discharge signal from the discharge sensor (14) and wirelessly communicate data associated with the discharge signal to a second node (12,1) in the communications network.

Description

SYSTEMS AND METHODS FOR COMMUNICATING A FIREARM DISCHARGE EVENT

TECHNICAL FIELD OF THE DISCLOSURE

This disclosure generally relates to firearms, and more particularly, to systems and methods for communicating a discharge event of a firearm over a distributed sensor network.

BACKGROUND OF THE DISCLOSURE

Military or law enforcement personnel may carry firearms for protection or offensive action. Particularly in a combat environment, it may be desirable to obtain and record information about a discharge event of a particular firearm or group of firearms. It may be desirable for information about the discharge event of a particular firearm to be communicated to and collected by interested parties to allow them to take appropriate action in light of this information. Currently, providing information about a discharge event of a firearm is largely a manual process, which requires an individual or a unit to report ammunition usage through radio reports, paperwork, and other manual procedures.

SUMMARY OF THE DISCLOSURE

According to one embodiment, a system for communicating a discharge event of a firearm includes a discharge sensor mechanically coupled to the firearm. The discharge sensor is operable to generate a discharge signal in response to a discharge event of the firearm. The system also includes a first node in a communications network. The first node is mechanically coupled to the firearm and is in communication with the discharge sensor. The first node is also operable to receive the discharge signal from the discharge sensor and wirelessly communicate data associated with the discharge signal to a second node in the communications network. Technical advantages of particular embodiments of the present disclosure may include the ability to monitor discharge events of firearms such that battlefield commanders may obtain and act on this information in near real time. Further technical advantages of embodiments of the present disclosure may include the ability to monitor a firearms usage to ensure that periodic maintenance is timely performed by accurately indicating when a particular firearm has discharged a certain number of rounds .

Yet further technical advantages of particular embodiments of the present disclosure may include the ability to automatically monitor and record discharge events of a firearm in a manner that is less intrusive to a user.

Other technical advantages will be readily apparent to one or ordinary skill in the art for the following figures, descriptions, and claims. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages .

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of embodiments of the disclosure will be apparent from the detailed description taken in conjunction with the accompanying drawings in which: FIGURE 1 is a diagram showing one embodiment of a firearm employing a firearm distributed sensor network according to teachings of the present disclosure;

FIGURE 2 is a block diagram of certain components of a mote according to teachings of the present disclosure;

FIGURE 3 illustrates a flow diagram of a method for communicating a discharge event of a firearm according to an embodiment of the present disclosure; and

FIGURE 4 is a diagram of a number of firearms that may be part of a firearm distributed sensor network according to teachings of the present disclosure.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

A firearm discharge event may be communicated using a distributed sensor network according to particular embodiments of the present disclosure. A distributed sensor network is a particular type of communication network in which one or more nodes in the network may transmit information to another centralized node, referred to as a data sink. In some cases the node transmitting to the centralized node is autonomous, and in that case the node is called a mote. The motes may be relatively small and simple in design such that a distributed sensor network may be configured with relatively little cost outlay. FIGURE 1 shows one embodiment of a firearm distributed sensor network 10 according to the teachings of the present disclosure. Firearm distributed sensor network 10 includes a mote 12 coupled to a discharge sensor 14 that is mounted on a firearm 16. When firearm 16 is discharged, discharge sensor 14 generates a signal indicative of the discharge event of firearm 16. Mote 12 receives the discharge signal from discharge sensor 14 through wire 15 and ultimately transmits this signal to a remotely configured data sink 18. As will be described in detail below, firearm distributed sensor network 10 may process a number of discharge signals from mote 12 to provide near real-time information about the operation of firearm 16.

Firearm 16 may be any device that discharges, or simulates the discharge of, bullets or other projectiles. Examples of firearms 16 may include rifles, pistols, revolvers, semi-automatic handguns, shotguns, and the like. Firearm 16 may be a military or a non-military firearm. An example of a military firearm may include a M-16A4 assault rifle or a M-4 assault rifle. An example of a non-military firearm may include a 12 -gauge shotgun, a pistol, or other weapon used in law enforcement. In the particular embodiment shown, mote 12 and data sink 18 form a portion of distributed sensor network 10. Using distributed sensor network 10, multiple motes 12 may be disposed over a geographic area and configured to transmit and/or relay information to data sink 18 (as shown in FIGURE 4) . Motes 12 of firearm distributed sensor network 10 may communicate with data sink 18 and/or other motes 12 using any suitable wireless communication protocol, for example, the Institute of Electrical and Electronics Engineers IEEE 802.11 wireless networking protocol. In the embodiment of FIGURE 1, mote 12 wirelessly communicates through a communication network with data sink 18 using electro-magnetic signaling techniques. Communication networks according to embodiments of the present disclosure may include local area networks (LANs) , metropolitan area networks

(MANs) , and wide area networks (WANs) .

In certain embodiments, mote 12 may be any type of communication node that transmits information and/or relays information from another mote 12 while data sink 18 may be any type of communication node that receives information transmitted by mote 12.

Discharge sensor 14 may be any suitable device that generates a signal indicative of a discharge action of firearm 16. In one particular embodiment, discharge sensor 14 may comprise an accelerometer that measures movement or vibration along one or more axes of a barrel

13 of firearm 16. In certain embodiments, discharge sensor 14 may detect shock waves caused by a bullet being discharged through barrel 13. The shock wave and frequency detected may be dependent on the type and caliber of the bullet.

Mote 12 may also include filtering and/or limit sensing circuitry such that inadvertent movement of the firearm 16 not resulting in a discharge of firearm 16 does not generate a false discharge signal. Discharge sensor 14 may be mounted to barrel 13 of firearm 16. In one embodiment, discharge sensor 14 and mote 12 may be embedded within firearm 16 such that it is hidden from view beneath a barrel shroud 17.

In another embodiment, configuration of mote 12 and discharge sensor 14 with firearm 16 may conform to military standard 810F (MIL-STD-810F) . The military standard 810F specifies various environmental criteria, such as gunfire shock, thermal exposure, humidity, and temperature extremes that mote 12 and distributed sensor

14 may undergo during operation.

To provide standardized attachment/detachment, mote 12 may incorporate a housing that allows mote 12 to be attached to a picatinny rail interface 19. Picatinny rail interface 19 may comply with military standard 1913 (MIL-STD- 1913) . Other embodiments may include any suitable configuration for mounting mote 12 to firearm 16.

In one embodiment, mote 12 may also be in communication with a geo-spatial sensor 20. Geo-spatial sensor 20 may be mounted on firearm 16 and configured to generate a geo-spatial signal indicative of the location of firearm 16. Geo-spatial sensor 20 may include a processor (not specifically shown) . In one embodiment, the processor that executes a sequential localization and mapping (SLAM) algorithm and an extended kalman filter (EKF) algorithm. The sequential localization and mapping algorithm may process received signals from other nearby objects having a location that is at least partially known. The extended kalman filter algorithm may be used to reduce noise from received signals to produce geo- spatial information that may be used by the firearm distributed sensor network 10.

FIGURE 2 illustrates a block diagram of certain components of mote 12. Mote 12 may be similar to a mini- computer, and may be used to sense almost anything including radio waves, sound, and even algae. In certain embodiments, mote 12 may include a sensor 24, a processor 26, memory 28, and a transceiver 30. Memory 28 may include portions for temporary storage of data and portions for permanent storage of data. Mote 12 may also include a transmit timer 32, a power source 34, and a generator 36. In some embodiments, mote 12 may use transceiver 30 to transmit and receive data wirelessly, and in some applications mote 12 may be disposable. Mote 12 and discharge sensor 14 may be powered by a suitable source of electrical power, such as power source 34, which may be a rechargeable battery, for example a nickel metal -hydride (NiMH) battery. Power source 34 may be coupled to a kinetic motion power generator 36 that uses the motion of firearm 16 to generate electrical power for energizing mote 12, recharging the battery and/or energizing discharge sensor 14 and/or geo-spatial sensor 20.

In one embodiment, mote 12 may incorporate a dynamic voltage scaling process. The dynamic voltage scaling process reduces voltage applied to the various components of mote 12 during periods of little usage to reduce power consumption. In another embodiment, mote 12 may incorporate a length-energy-constrained (LEC) routing technique. The length-energy-constrained routing technique causes messages to be transmitted and/or received in a manner that reduces power usage by each of the member motes 12.

FIGURE 3 illustrates a flow diagram of a method for sensing a discharge event of a firearm and transmitting data associated with that event in firearm distributed sensor network 10 in accordance with embodiments of the present disclosure. The steps of FIGURE 3 may be best understood with reference to FIGURES 1 and 2. The method of FIGURE 3 begins at step 38 where a discharge event is sensed by discharge sensor 14.

As previously discussed, discharge sensor 14 may, for example, detect shock waves or a particular frequency caused by a bullet being discharged through barrel 13 of firearm 16. At step 40, data associated with the discharge event is communicated from discharge sensor 14 to mote 12 through wire 15 (or other suitable communications medium) . The reception of this data by sensor 24 of mote 12 may cause processor 26 to start transmit timer 32 at step 42. Transmit timer 32 may count down a predetermined time in which information or data associated with discharge events may be stored in memory 28 of mote 12 before being transmitted to another node in firearm distributed sensor network 10.

At step 43, the discharge event may be stored in a portion of memory 28 of mote 12 designated for temporary storage of data. At step 44, the discharge event may also be stored in a portion of memory 28 designated for permanent storage of data. Memory 28 may be any suitable form of temporary and/or permanent memory to store data associated with a discharge event. At step 46, processor 26 may cause a count to be incremented by one. The count indicates that one bullet has been fired through barrel 13.

At step 48, processor 26 in conjunction with transmit timer 32 may make a determination as to whether a pre-determined time has elapsed since receiving the discharge signal by sensor 24. The pre-determined time may be selected such that mote 12 is allowed to gather and collect data associated with multiple discharges of bullets through barrel 13, but still transmit information associated with those discharges such that it can be received and acted on in approximately real time. Allowing memory 28 in mote 12 to accumulate data associated with multiple discharge events, as opposed to transmitting data after each discharge event, may reduce the amount of power usage required by mote 12, an thus may reduce the size of power source 34. Discharge events may typically occur in short groupings of multiple shots. Waiting the pre-determined time may allow mote 12 to sum an amount of discharge events over a relatively short period of time and transmit a single message rather than multiple messages, which may allow mote 12 to be smaller in size and draw less power to operate. In certain embodiments, the pre-determined time may be between five and ten seconds. In particular embodiments, a predetermined time of seven seconds may allow a suitable accumulation of data associated with discharge events in mote 12 and still allow for approximately near real time data transmission. However, any amount of time, including transmission after each discharge event, may by employed in accordance with teachings of embodiments of the present disclosure. If the predetermined time has elapsed, then at step 50 mote 12 transmits the data in the temporary portion of memory 28 using transceiver 30. This transmission may be a wireless transmission to a nearby mote in the network or may be directly to a data sink. In certain embodiments, the data may be transmitted to the node

(mote or data sink) in the network that is nearest in proximity to mote 12. At step 52, the temporary portion of memory 28 of mote 12 may be cleared and the method ends . The flow diagram of FIGURE 3 illustrates a single cycle of storing and transmission of data associated with discharge events by mote 12. If another discharge event is sensed, then the cycle begins again at step 38 and continues as previously described. Some of the steps illustrated in FIGURE 3 may be combined, modified, or deleted where appropriate, and additional steps may also be added to the flow diagrams. Additionally, steps may be performed in any suitable order without departing from the scope of the invention. FIGURE 4 shows an example diagram of a firearm distributed sensor network 10 in accordance with an embodiment of the present disclosure. In this embodiment, data associated with discharge events of a number of firearms 16 may be monitored by an information processing system 22. A mote 12 may communicate with its respective data sink 18 through other motes 12 configured in the network in a daisy-chain type fashion. That is, a mote 12 may communicate with the mote 12 nearest to it in the network. This communication from mote 12 to mote 12 may continue until the data from the initial transmission reaches data sink 18. Data from data sink 18 may be communicated to processing system 22 where analysis of this data may provide near real-time information about the operation of firearms 16.

Motes 12 may be configured on multiple firearms 16 that each transmit data associated with a discharge event to a central data sink 18. Motes 12 of distributed sensor network 10 may communicate directly with data sink 18 or through other motes 12 configured in distributed sensor network 10. In the particular example shown, motes 12 are configured on military firearms 16 used by a number of military personnel. Using firearm distributed sensor network 10, the operation of firearms 16 by multiple military personnel may be monitored.

Information processing system 22 may be configured on any suitable computing system, such as a personal computer, laptop computer, personal digital assistant (PDA) , mainframe computer, or a network computing system. Information processing system 22 wirelessly receives data associated with discharge signals from motes 12 and derives information according to that received information. Certain embodiments of the present disclosure may provide various advantages . One advantage may be logistical support. During a mission, battlefield commanders may determine which firearms 16 are experiencing the heaviest usage and thus may be in need of ammunition replenishment. Another advantage may be battlefield awareness. Battlefield commanders may obtain near real-time information as to where combat is occurring. By correlating discharge information with geo-spatial information, specific areas of combat intensity throughout a combat region may be determined.

Another advantage may be combat forensics. Following a military battle, discharge events may be analyzed to aid in after-action debriefings, criminal investigations, and/or battle reconstruction models.

Another advantage may be maintenance of firearm 16. Because discharge events may be permanently stored in memory 28, maintenance may be performed at periodic intervals based upon usage of firearm 16. For example, a maintenance schedule for a particular firearm 16 may specify replacement of barrel 13 following discharges of greater than 20,000 rounds. The data stored in the permanent portion of memory 28 may enable monitoring the firearm's usage such that periodic maintenance may be properly performed.

Firearm distributed sensor network 10 may include a security protocol for reducing the possibility of various cyber attacks, such as eavesdropping or spoofing. In one embodiment, mote 12 communicates with other motes 12 and/or data sink 18 using a security protocol for sensor network (SNIPS) protocol. The security protocol for sensor network protocol includes a sensor network encryption protocol (SNEP) portion and a μTesla portion. The sensor network protocol portion provided semantic security, data authentication, replay protection, weak freshness, and/or micro- communication overhead. The μTesla portion uses two-way keys to authenticate broadcasts using a symmetric mechanism, one key disclosure per epoch, and restructuring the number of users. In other embodiments, other suitable security protocols to protect communications in firearm distributed sensor network 10 may be used. For example, some embodiments may employ a Cooperative Security Protocol, a Localized Encryption and Authentication Protocol, and/or a Lightweight Security Protocol.

Although several embodiments have been illustrated and described in detail, it will be recognized that substitutions and alterations are possible without departing from the spirit and scope of the present disclosure, as defined by the following claims.

Claims

What is claimed is:

1. A system for communicating a discharge event of a firearm, comprising: a firearm; a discharge sensor mechanically coupled to a barrel of the firearm, the discharge sensor operable to generate a discharge signal in response to a discharge event of the firearm,- a first mote mechanically coupled to the firearm and in communication with the discharge sensor, the first mote operable to receive the discharge signal from the discharge sensor and wirelessly communicate data associated with the discharge signal to a data sink or a second mote mechanically coupled to a second firearm, the first mote, the second mote, and the data sink each being part of a distributed sensor network; a battery coupled to the firearm and being operable to power the discharge sensor and the first mote, the battery being further coupled to a kinetic motion power generator such that the battery is operable to be charged in response to movement of the firearm; and the first mote comprising a memory operable to store data associated with the discharge signal for a predetermined time, and the first mote being further operable to transmit data associated with a plurality of discharge signals received during the predetermined amount of time once the predetermined amount of time elapses .

2. A system for communicating a discharge event of a firearm, comprising: a firearm; a discharge sensor mechanically coupled to the firearm, the discharge sensor operable to generate a discharge signal in response to a discharge event of the firearm; and a first node in a communications network, the first node mechanically coupled to the firearm and in communication with the discharge sensor, the first node operable to receive the discharge signal from the discharge sensor and wirelessly communicate data associated with the discharge signal to a second node in the communications network.

3. The system of Claim 2, wherein: the communications network comprises a distributed sensor network; the first node comprises a mote,- and the second node comprises a data sink.

4. The system of Claim 2, wherein: the communications network comprises a distributed sensor network; the first node comprises a first mote; and the second node comprises a second mote coupled to a second firearm, each of the first and second motes operable to communicate data associated with the discharge signal to a third node in the network.

5. The system of Claim 4, further comprising: a first distance between the first mote and the second mote; a second distance between the first mote and the third node,- the first mote operable to communicate the data associated with the discharge signal to the second mote if the first distance is less than the second distance; and the first mote operable to communicate data associated with the discharge signal to the third node if the second distance is less than the first distance.

6. The system of Claim 2, further comprising a battery operable to power at least the first node, the battery being further coupled to a kinetic motion power generator such that the battery is operable to be charged in response to movement of the firearm.

7. The system of Claim 6, wherein the battery is further operable to power the discharge sensor.

8. The system of Claim 2, further comprising a geo-spatial sensor coupled to the firearm.

9. The system of Claim 2, wherein the discharge sensor is an accelerometer coupled to a barrel of the firearm.

10. The system of Claim 2, wherein the first node is operable to store the data associated with discharge signal for a predetermined amount of time, the first node being further operable to transmit the data associated with discharge signal to the second node once the predetermined amount of time has elapsed.

11. The system of Claim 2, further comprising a picatinny rail coupled to the firearm, the first node being coupled to the picatinny rail .

12. The system of Claim 2, wherein the discharge sensor and the first node comprise a single component.

13. A method for communicating a discharge event of a firearm, comprising: sensing a discharge event of a firearm using a discharge sensor located on the firearm; generating a discharge signal in response to the discharge event; communicating the discharge signal to a first node in a communications network, the first node comprising a memory operable to store a count associated with the discharge signal as data in the memory; incrementing the count in the memory in response to receiving the discharge signal; determining that a predetermined time has elapsed since receiving the discharge signal, and in response ; transmitting the data in the memory to a second node in the communications network.

14. The method of Claim 13, wherein the predetermined time is greater than or equal to five seconds and less than or equal to ten seconds.

15. The method of Claim 13, wherein a plurality of discharge signals are communicated to the first node within the predetermined time, and each received discharge signal increments the count by one.

16. The method of Claim 13, further comprising clearing the data in at least a temporary portion of the memory .

17. The method of Claim 16, further comprising: sensing a second discharge event of the firearm using the discharge sensor located on the firearm after clearing the data in at least the temporary portion of the memory; generating a second discharge signal in response to the second discharge event; communicating the second discharge signal to the first node in the communications network; incrementing the count in the memory in response to receiving the second discharge signal; determining that a second predetermined time has elapsed since receiving the second discharge signal, and in response; transmitting the data in the memory to the second node in the communications network.

18. The method of Claim 13, wherein: the first and second nodes comprise a distributed sensor network; the first node comprises a mote; and the second node comprises a data sink.

19. The method of Claim 13, wherein: the first and second nodes comprise a distributed sensor network; the first node comprises a first mote; and the second node comprises a second mote coupled to a second firearm.

20. The method of Claim 19, further comprising: communicating the data from the first mote to the second mote if a first distance from the first mote to the second mote is less than a second distance from the first mote to a third node in the distributed sensor network; and communicating the data from the first mote to the third node if the second distance is less than the first distance.