Patent Application
20160076848
Conventional live fire simulation systems for use by military and law enforcement personnel can generate visual and auditory effects to simulate live fire from a weapon, such as from small fire arms. Most systems can simulate a muzzle flash, which is a visual effect resulting from firing a weapon, and a muzzle blast, which is a sound of high pressure and short duration that results from firing a weapon. However, those systems are typically limited in that they are unable to simulate the sonic boom or shockwave that emanates from a bullet or other projectile while in flight. This sound, heard as a loud, sharp crack, creates the perception of being fired upon, and is usually only perceived as a result of a bullet moving at supersonic speed past an observer.
In addition, most simulation systems are large and difficult to move, are insufficiently rugged to be used in harsh training environments, and/or rely on an external power source for operation.
It would be advantageous to provide a transportable system that can simulate each of the muzzle blast, shockwave, and muzzle flash associated with small arms fire, but also be sufficiently rugged to withstand harsh environments.
Accordingly, in one aspect, the disclosure relates to a system for simulating small arms fire. The system includes a parabolic reflector, a speaker system, an amplifier, and a memory. The speaker system includes a speaker located at the focus of the parabolic reflector. The amplifier is for driving the speaker system. The memory is for storing an audio signal including a muzzle blast signal and a shockwave signal. The controller is configured to cause the amplifier to output the audio signal stored in the memory via the speaker system, thereby simulating the audio effects of firing a firearm.
In some implementations, the parabolic reflector, speaker system, memory and controller are included within or coupled to a common housing. In some implementations, the system includes a tripod coupled to the housing. In some implementations, the shockwave signal comprises a noise signal having a first power spectrum, which when output through the speaker system, results in a sound wave, which, after travelling a distance, has a second power spectrum, the second power spectrum substantially matching the power spectrum of a shockwave associated with a passing projectile.
In some implementations, the muzzle blast signal is between about 0.01 and 0.15 seconds long. In some implementations, the speaker system includes at least two coaxial speaker elements associated with different frequency ranges. In some implementations, the system further includes a light source configured to emit flashes simulating the muzzle flash exhibited by small arms fire, and wherein the controller is configured to cause the amplifier to output the audio signal in coordination with causing the light source to emit a light flash. In some implementations, the system further includes a transceiver for receiving the audio signal, wherein the controller is configured to store the received audio signal in the memory.
In some implementations, the system includes a operator interface configured to receive an indication of at least one of a fire arm to simulate and a firing pattern to simulate. In some implementations, the operator interface is integrated into the controller. In other implementations, the operator interface is separate from the controller and is configured to communicate with the controller via a wireless communication interface. In some implementations, the memory stores a plurality of audio signals corresponding to a respective plurality of firearms.
In some implementations, the shockwave signal comprises a frequency weighted white noise signal. In some implementations, the shockwave signal comprises a first portion separated from a second portion separated by a pause. In some implementations, the shockwave signal exhibits a reduced amplitude at low frequencies at a beginning and end of the shockwave signal.
In another aspect, the disclosure relates to a method for simulating small arms fire. The method includes driving a speaker system positioned at about a focal point of a parabolic reflector to output an audio signal including a first portion corresponding to a firearm muzzle blast and a second portion corresponding to a shockwave. The second portion of the audio signal comprises a noise signal having a first power spectrum, which when output through the speaker, results in a sound wave, which, after travelling a distance, has a second power spectrum, the second power spectrum substantially matching the power spectrum of a shockwave associated with a passing projectile.
In some implementations, the speaker system includes a plurality of coaxially arranged speakers, each speaker corresponding to a different frequency range. In some implementations, the method further includes flashing a light source in synchronicity with outputting the first portion of the audio signal to simulate a fire arm muzzle flash. In some implementations, the method further includes receiving an identification of the audio signal to output from a operator interface, and retrieving the audio signal from a memory storing at least one other audio signal corresponding to a different firearm. In some implementations, the method further includes receiving from a operator interface an indication of a firing pattern to simulate, and repeating the output of the audio signal according to the firing pattern.
In some implementations, driving the speaker system to output the shockwave signal comprises driving the speaker to output two audio signals separated by a pause. In some implementations, the shockwave signal comprises a frequency weighted white noise signal. In some implementations, the shockwave signal exhibits a reduced amplitude at low frequencies at a beginning and end of the shockwave signal. In some implementations, driving the speaker system to output the audio signal comprises separating in time the output of the first portion of the audio signal from the output of the second portion of the audio signal based on a simulated firing distance.
The above and related objects, features, and advantages of the present disclosure will be more fully understood by reference to the following detailed description, when taken in conjunction with the following figures, wherein:
Aspects and implementations of the present disclosure generally relate to a system and method for simulating the muzzle blast, shockwave, and muzzle flash associated with small arms fire, such as from an assault rifle (e.g., an AK-47 assault rifle, etc.), a machine gun (e.g., an M240-B machine gun, a PKM general purpose machine gun, etc.), an automatic weapon (e.g., an M249 Squad Automatic Weapon, etc.), a sniper rifle, or other type of firearm, such as a hand gun. The system is configured to deliver waveforms to an observer that will be perceived in substantially the same fashion as how that observer would perceive the muzzle blast of the weapon being simulated and the shockwave of a projectile fired by that weapon passing in proximity to the observer. The system is also configured to generate a muzzle flash timed appropriately with the shockwave and muzzle blast to simulate a complete shot fired from a weapon. In this way, the system allows users, such as military and law enforcement personnel (or others), to practice or train for situational awareness of, or merely to experience the effects of, small arms fire.
As used herein, the term “observer” refers to any intended recipient of the audio or visual effects of the systems described herein. The term “operator” refers to any person who controls or operates the system. In some implementations, an observer can also be an operator. Likewise, in some implementations, an operator can also be an observer.
When shooting a fire arm, several visual and auditory effects are generated that enable a person under fire to perceive the effective fire (i.e., bullets directed toward them) and to distinguish from bullets directed away from them. One visual effect is the muzzle flash located near the firing weapon. As noted above, existing devices/systems can simulate the muzzle flash as well as the muzzle blast associated with small arms fire. Depending on the weapon and ambient conditions, the muzzle blast lasts for about 0.004 seconds and reaches a peak pressure of about 160 decibels. This sound is difficult to simulate, so some existing simulation systems use, for example, explosive cartridges to replicate the muzzle blast sound. Although the muzzle flash and muzzle blast vary slightly with the orientation of the weapon, they are present regardless of the direction of the small arms fire (i.e., whether or not the weapon is directed toward the observer). Another audio effect, the shockwave, is typically only perceived if a supersonic bullet passes near the observer. Absent a shockwave, existing systems merely replicate the noise and chaos of the battlefield without generating the additional auditory effects necessary to practice situational awareness. That is to say, most existing systems are unable to simulate the shockwave along with the muzzle blast and muzzle flash necessary to create an effective training environment or other simulation of live fire.
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In one implementation, the parabolic reflector 105 has a diameter of about 0.8 meters. In other implementations, the diameter of the parabolic reflector 105 may be larger to improve the reflection of sound waves having low frequencies. In other implementations, the diameter may be smaller to reduce the overall footprint of the reflector 105. For example, in some implementations the diameter can be in the range of about 0.5 meters to about 2.0 meters. In the implementation shown in
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A power source in the form of a battery 135 is coupled within the enclosure 110. In other implementations (not shown), the battery 135 may be coupled to a different portion of the enclosure 110, such as an outer wall. In one implementation, the battery 135 is a twenty-four Volt rechargeable, lithium-ion battery, such as the BB2590 lithium ion rechargeable battery commonly used in various military applications. In other implementations, the battery 135 is a different type of power source, such as a solar panel, a wind power generator, or another power source suitable to provide power to operate the system 100. In one implementation, the battery 135 is operatively connected to the amplifier 140 via a boost converter 130. The battery 135 is configured to provide power to the boost converter 130 to operate the system 100 (e.g., to drive the speaker system 120, etc.). For example, in one implementation, the battery 135 can provide twenty-four Volts to the boost converter 130. The boost converter 130 can then provide sixty Volts direct current (DC) to the amplifier 140 to drive the speaker system 120. In some implementations (not shown), a portion of the enclosure 110 includes heat transfer elements or devices (e.g., cooling fins, openings, fans, etc.) to increase heat transfer between the boost converter 130 and the ambient environment to provide effective cooling for the system 100 when the system is operating.
In some implementations (not shown), the system 100 includes a buck converter configured to receive power (e.g., about twenty-four Volts) from the battery 135. The buck converter can provide power (e.g., about five Volts direct current) to a controller/control system for the system 100. In one implementation (not shown), the buck converter may be coupled within the enclosure 110, although the buck converter may be coupled to a different portion of the enclosure 110, according to other implementations (not shown).
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In one implementation, the control system 119 is configured to send a control signal to an audio player (e.g., an MP3 player, a CD player, etc.) (not shown) such that the audio player can output an audio signal to the amplifier 130, to thereby drive the speaker system 120. In one implementation (not shown), the audio player is located within the enclosure 110 near the operator interface 115, although the audio player may be located at a different position, according to other implementations. In some implementations, the audio signal can include a muzzle blast signal and a shockwave signal suitable to simulate the auditory effects of small arms fire. In one implementation, the operator interface 115 includes a memory 129 for storing data, such as audio data signals corresponding to different firearms, different firing patterns, and the like. The memory 129 can store a plurality of audio signals each having waveforms comprised of a muzzle blast waveform and a modified shockwave waveform. In various implementations, the waveforms can correspond to the auditory effects of different fire arms, such as an assault rifle (e.g., an AK-47 assault rifle, etc.), a machine gun (e.g., an M240-B machine gun, a PKM general purpose machine gun, etc.), or an automatic weapon (e.g., an M249 Squad Automatic Weapon, etc.). In other implementations, the waveforms can correspond to the auditory effects of another type of weapon, such as a hand gun.
According to one implementation, the muzzle blast waveforms used by the system 100 are created from high-quality recordings of a weapon firing. Although the parabolic reflector 105 allows for the use of muzzle blast waveforms having a duration much shorter than the 0.4 second duration waveform used in existing simulators, it is necessary to lengthen the duration of the muzzle blast waveform to achieve an appropriate level of perceived loudness to an observer. In one implementation, the muzzle blast signal has a duration of between about 0.01 seconds and about 0.15 seconds.
In one implementation, the shockwave waveforms used by the system 100 are generated by applying an appropriate gain function to a white noise signal. For example,
According to one implementation, the shockwave waveform used by the system 100 is modified to create the perception of proximity to an observer. For example, in one implementation, an observer is treated as being located about 110 meters from the parabolic reflector 105, although the precise distance is not critical and a different distance could be used, according to other implementations. First, the high frequency components of the waveform are augmented in proportion to their attenuation in about 110 meters of air. High frequency sounds are attenuated in air more rapidly than low frequency sounds. Thus, human beings perceive the distance of sound, in part, by the relative amplitude of the high and low frequencies.
Second, the low frequency components are removed from the beginning and end of the signal. Depending on the particular frequency, the low frequency components are faded in at the beginning of each sound signal and faded out at the end of the sound signal. That is to say, the shockwave signal has a reduced amplitude at low frequencies at a beginning and end of the signal. As low frequency sounds are propagated, they spread out, such that the sound perceived by the observer is longer in duration than the actual sound produced. As a result, sounds that are far from the listener have brief, low-frequency tails, which enable the listener to perceive the sound as originating from far away. This frequency augmentation in combination with the sound pressure created by the speaker system 120 and the parabolic reflector 105, create the perception that a shockwave occurred within close proximity to an observer. The muzzle blast signal is not modified in this way, because the perceived location of the source is the same as the actual location. In one implementation, both of the above described waveforms (i.e., the shockwave and the muzzle blast waveforms) are combined into a single data signal to simulate the auditory effects of small arms fire.
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Typically, with most fire arms, the muzzle flash travels at the speed of light, the sonic boom travels at the speed of a supersonic bullet, and the muzzle blast travels at the speed of sound. As a result, the muzzle flash is usually perceived by an observer first, followed by the shockwave, which is then followed by the muzzle blast. To achieve this sequence of events, in one implementation, the system 100 is configured to produce the shockwave first, followed by the simultaneous production of the muzzle flash and the muzzle blast. The time between the first and the last effect is approximately 0.2 seconds, depending on the particular fire arm simulated. In some implementations, the time between effects can vary based on different simulated distances from a fire arm (i.e., distances perceived by an observer). That is, in some implementations, the system 100 is configured to simulate different distances from the fire arm source relative to an observer without moving the system 100. For example, in one implementation, the shockwave is produced at time to0.05 seconds, where to is the time at which the shot is fired. The muzzle flash is produced at time to and the muzzle blast is produced at time to+0.10 seconds, according to one implementation. In other implementations, the timing may be different between effects, such that an observer perceives the simulated fire arm blast from different distances. However, the order of the effects can remain constant to create effective simulation.
To create effective situational awareness, in one implementation, the shockwave signal occurs in approximately one-fifth of the shots fired/simulated by the system 100. According to other implementations, the shockwave signal can occur at a different rate depending on the particular fire arm simulated. In most combat environments, the majority of the bullets fired will not pass close enough to the observer to create the perception of a shockwave. Therefore, in one implementation, the amplitude of the shockwave signal is varied to simulate the effect of some bullets passing close to an observer and others having some amount of separation from the observer. In other implementations, the shockwave signal can occur at a different frequency depending on the particular fire arm being simulated.
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According to one implementation, an operator can select a firing pattern to simulate via the system 100 (e.g., via the operator interface 115). The various firing patterns can include, for example, intermittent, sustained, rapid, and cyclic/automatic patterns, among others. The particular firing rate associated with the different firing pattern depends on the fire arm. The firing rate for each fire arm is important, because an observer can distinguish between fire arms more easily by their firing rates than by differences in individual muzzle blasts. In one implementation, each audio file associated with a firing pattern has a duration of about one minute. If an operator of the system 100 selects a duration of less than one minute via the operator interface 115, the audio file is truncated. Likewise, if an operator of the system 100 selects a duration of greater than one minute via the operator interface 115, the audio file is looped to meet the selected duration. In some implementations, a single audio file of an individual shot from a fire arm is played multiple times according to a simulated pattern. In other implementations, the audio file corresponding to the different firing patterns has a different duration.
In one implementation, the system 100 includes six different firing patterns associated with a plurality of different fire arms. The various firing patterns can be stored within the memory 129, according to one implementation. The first firing pattern, “Intermittent I,” includes two rounds per minute with each shot having an associated shockwave. The second firing pattern, “Intermittent II,” includes six rounds per minute with three of the shots having an associated shockwave. The third firing pattern, “Intermittent III,” includes twenty rounds per minute with one-third of the shots having an associated shockwave. This pattern can fire one or two shots at a time, according to one implementation. When two shots are fired, there is a delay of about 0.3 seconds between shots, according to another implementation. The fourth firing pattern, “Sustained,” includes forty-three rounds per minute with one-fourth of the shots having an associated shockwave. This pattern can fire groups of one to three, with a delay of about 0.3 seconds between shots within a group, according to one implementation. The fifth firing pattern, “Rapid,” includes eighty-seven rounds per minute with one-fifth of the shots having an associated shockwave. This pattern can fire groups of one to four, with a delay of about 0.24 seconds between shots within a group, according to one implementation. Finally, the sixth firing pattern, “Automatic,” includes three hundred and sixty rounds per minute with one-fifth of the shots having an associated shockwave. This firing pattern can have a delay of about 0.1 seconds between shots and a pause of about two seconds every thirty rounds, according to one implementation. It should be noted that the above described patterns are merely exemplary, and that other patterns can be used without departing from the scope of the disclosure.
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In the various implementations described herein, CPU 127 may be implemented as a general-purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a digital-signal-processor (DSP), a group of processing components, or other suitable electronic processing components. Memory 129 is one or more devices (e.g., RAM, ROM, Flash Memory, hard disk storage, etc.) for storing data and/or computer code for facilitating the various processes described herein. Memory 129 may be or include non-transient volatile memory or non-volatile memory. Memory 129 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described herein. Memory 129 may be communicably connected to CPU 127 and provide computer code or instructions to CPU 127 for executing the processes described herein.
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In one implementation, receiving a request to produce an audio signal (step 605) can include receiving an input from the operator interface 115 in the form of a signal corresponding to a desired fire arm to simulate, a firing pattern to simulate, and/or a duration for the simulation. The signal is transmitted to the memory 129 of the control system 119, where the selected audio signal is retrieved (step 610). Based on the selected audio signal, method 600 includes flashing a light source (e.g., the muzzle flash simulator 125, etc.) to simulate a muzzle flash associated with the selected audio signal (step 613) (i.e., the selected fire arm, firing pattern, and/or duration to be simulated).
The method 600 also includes driving the speaker system 120 (step 615) to output both a shockwave audio signal (620) and a muzzle blast audio signal (625). In one implementation, driving the speaker system 120 includes separating in time the output of the shockwave audio signal (step 620) from the output of the muzzle blast audio signal (step 625) based on a simulated firing distance to create the impression of proximity to an observer. In one implementation, the muzzle flash produced at (step 613) is produced in synchronicity with outputting the muzzle blast audio signal at (step 625) to simulate a complete shot fired from a fire arm. In another implementation, the shockwave audio signal produced at (step 620) is separated from the muzzle blast audio signal of (step 625) by a pause. In one implementation, the shockwave signal of (step 620) is composed of a frequency weighted white noise signal. In another implementation, the shockwave signal of (step 620) has a reduced amplitude at low frequencies at a beginning and at an end of the signal.
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In the various implementations disclosed herein, the system 100 includes standard military equipment readily available to most military personnel. For example, as described above, in some implementations the system 100 uses a power source in the form of a BB2590 lithium ion rechargeable battery to operate the system 100. Furthermore, in some implementations, the system 100 uses a support structure in the form of the M192 Lightweight Ground Mount to support the system 100. According to other implementations, the system 100 includes additional standard military components/equipment suitable for the particular application of the system 100. By using standard military equipment, the system 100 is easily repairable, is sufficiently rugged, and is familiar to most observers and/or operators using the system in a military environment.
The present disclosure contemplates methods, systems, and program products on any machine-readable media for accomplishing various operations. The implementations of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Implementations within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.
While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any inventions or of what may be claimed, but rather as descriptions of features specific to particular implementations of particular inventions. Certain features that are described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.
References to “or” may be construed as inclusive so that any terms described using “or” may indicate any of a single, more than one, and all of the described terms. The labels “first,” “second,” “third,” and so forth are not necessarily meant to indicate an ordering and are generally used merely to distinguish between like or similar items or elements.
Having described certain implementations, it will now become apparent to one of skill in the art that other implementations incorporating the concepts of the disclosure may be used. Therefore, the disclosure should not be limited to certain implementations, but rather should be limited only by the spirit and scope of the following claims.
This Application claims the benefit of and priority to U.S. Provisional Application No. 62/013,236, filed on Jun. 17, 2014, the entire disclosure of which is incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 62013236 | Jun 2014 | US |
