TECHNICAL FIELD
[0001] Aspects relate, in general, to the control of emission characteristics of a projectile,
and more specifically, although not exclusively to control of a source of electromagnetic
radiation provided in a projectile.
BACKGROUND
[0002] A projectile, such as a bullet, can be propelled from the barrel of a gun using propellant
in the form of, e.g., a chemical explosive. Some projectiles, typically termed tracers
or tracer rounds, can be used to provide a visible trajectory to enable the flight
path of the projectile to be determined. The visible trajectory thus enables a user
to visualise the path of the projectile, and to make ballistic alterations so as to
correct the flight path and thus ultimately the end impact point of the projectile.
Such projectiles can comprise a pyrotechnic composition that is ignited when the round
is fired. The composition is such that the visible trajectory can be seen by the naked
eye in daylight as well as night-time. The pyrotechnic composition, being incendiary
in nature, can be unintentionally ignited. Furthermore, such compositions can be unreliable
in terms of, e.g., the nature of light produced and the duration over which the composition
burns due to variations that may occur during manufacture or storage.
SUMMARY
[0003] According to a first aspect, there is provided a method for modifying the emission
profile of a source of electromagnetic radiation in a non-incendiary projectile, the
method comprising receiving data defining the emission profile at a controller configured
to control the output of the source of EM radiation, and using the data, applying
emission settings of the source of EM radiation at the controller. The emission settings
can comprise at least one of a: brightness profile, wavelength emission profile, pulse
profile, and timing profile. A brightness profile can define a measure of brightness
of the source of EM radiation over a preselected period of time. A wavelength emission
profile can define an emission wavelength of the source of EM radiation over a preselected
period of time. A pulse profile can define a regular or irregular series of emissions
of the source of EM radiation over a preselected period of time. The source of EM
radiation can enter a non-emissive state in periods between the series of emissions,
i.e., it can be switched off. The timing profile can define a start time and/or an
end time for the output of the source of EM radiation.
[0004] In an implementation of the first aspect, the source of EM radiation comprises one
or more LEDs and/or laser diodes. The emission settings can be applied over a physical
communications link to the projectile. The emission settings can be applied over a
wireless communications link to the projectile. The emission settings can be applied
using the data.
[0005] The wavelength emission profile can define a change in the emission wavelength of
the source of EM radiation over a preselected period of time. One or more of multiple
sources of EM radiation can be selectively energised, wherein the multiple sources
of EM radiation are configured to emit EM radiation at respective selected wavelengths.
The emission profile can encode a data stream to be transmitted from the source. The
emission profile can define a randomly modulated emission characteristic of the source.
[0006] According to a second aspect, there is provided a projectile, comprising a source
of electromagnetic radiation, and a controller to receive data defining an emission
profile, the controller configured to regulate an output of the source of EM radiation
using the data, and apply emission settings for the source of EM radiation. The source
of EM radiation can comprise one or more LEDs and/or laser diodes. The projectile
can further comprise a physical communications link. The projectile can further comprise
a wireless communications link.
[0007] In an implementation of the second aspect, the controller is configured to regulate
or drive the source of EM radiation according to the emission profile by selectively
energising the source of EM radiation. An electrical contact communicatively coupled
to the controller can be provided, the contact disposed on or within a portion of
the surface of the projectile. The contact can extend circumferentially around the
surface of the projectile. The controller can comprise a memory configured to store
data to map an emission profile to an emission setting.
[0008] According to a third aspect, there is provided a non-transitory machine-readable
storage medium encoded with instructions for modifying the emission profile of a source
of electromagnetic radiation in a non-incendiary projectile, the instructions executable
by a processor of a machine whereby to cause the machine to receive data defining
the emission profile at a controller configured to control the output of the source
of EM radiation, and using the data, apply emission settings of the source of EM radiation
at the controller. The non-transitory machine-readable storage medium can comprise
further instructions executable by a processor of a machine whereby to cause the machine
to map an emission profile to an emission setting; selectively energise one or more
of multiple sources of EM radiation, wherein the multiple sources of EM radiation
are configured to emit EM radiation at respective selected wavelengths.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Embodiments will now be described, by way of example only, with reference to the
accompanying drawings, in which:
Figure 1 is a schematic representation of a projectile according to an example;
Figure 2 is a schematic representation of a projectile according to example;
Figure 3 is a schematic representation of a projectile according to example; and
Figure 4 is schematic representation of a controller according to an example.
DESCRIPTION
[0010] Example embodiments are described below in sufficient detail to enable those of ordinary
skill in the art to embody and implement the systems and processes herein described.
It is important to understand that embodiments can be provided in many alternate forms
and should not be construed as limited to the examples set forth herein.
[0011] Accordingly, while embodiments can be modified in various ways and take on various
alternative forms, specific embodiments thereof are shown in the drawings and described
in detail below as examples. There is no intent to limit to the particular forms disclosed.
On the contrary, all modifications, equivalents, and alternatives falling within the
scope of the appended claims should be included. Elements of the example embodiments
are consistently denoted by the same reference numerals throughout the drawings and
detailed description where appropriate.
[0012] The terminology used herein to describe embodiments is not intended to limit the
scope. The articles "a," "an," and "the" are singular in that they have a single referent,
however the use of the singular form in the present document should not preclude the
presence of more than one referent. In other words, elements referred to in the singular
can number one or more, unless the context clearly indicates otherwise. It will be
further understood that the terms "comprises," "comprising," "includes," and/or "including,"
when used herein, specify the presence of stated features, items, steps, operations,
elements, and/or components, but do not preclude the presence or addition of one or
more other features, items, steps, operations, elements, components, and/or groups
thereof.
[0013] Unless otherwise defined, all terms (including technical and scientific terms) used
herein are to be interpreted as is customary in the art. It will be further understood
that terms in common usage should also be interpreted as is customary in the relevant
art and not in an idealized or overly formal sense unless expressly so defined herein.
[0014] The use of pyrotechnic compositions in, e.g., incendiary tracers means that the location
of the shooter can easily be determined by simple visual inspection of the starting
point of the visible path that has been caused by ignition of the pyrotechnic agent
in question, particularly since the light that is emitted is visible over a large
number of viewing angles due to scattering of light in the smoke trail resulting from
combustion of the pyrotechnic composition. This can be detrimental to a user if there
are hostile observers in the vicinity. Nevertheless, the pyrotechnic compositions
used are generally incapable of being modified or tuned to overcome this drawback.
Furthermore, since the pyrotechnic composition is gradually exhausted as the tracer
is in flight, the trajectory will alter in a manner that is different to that of non-tracer
projectiles. This is in addition to the issue noted above with respect to storage
and manufacture.
[0015] Non-incendiary tracers - that is, tracers that do not use pyrotechnic compositions
to generate a visible path of the trajectory of the tracer - can be utilised. For
example, a source of electromagnetic radiation, such as a rearwardly directed electrically
powered light source that is configured to emit light as the tracer is in flight,
can be used. The light source can be powered using a battery, such as a coin cell
battery for example, which is also capable of providing power for any driving circuitry.
[0016] According to an example, there is provided a method for modifying the emission profile
of a source of electromagnetic radiation in a non-incendiary projectile. The source
of electromagnetic radiation can comprise a light source, such as an LED or laser
diode, or multiple LEDs/laser diodes. Accordingly, when referred to herein, a source
can comprise a single device configured to emit EM radiation, or multiple devices
each of which is capable of emitting EM radiation in the same or multiple wavelength
bands/ranges of the EM spectrum.
[0017] The method comprises receiving data defining the emission profile at a controller
configured to control the output of the source of EM radiation, and, using the data,
applying emission settings of the source of EM radiation at the controller. Accordingly,
the output of the source of electromagnetic radiation can be controlled according
to an emission profile. Such an emission profile can define multiple emission settings
for the source of EM radiation. Such emission settings can comprise, for example,
settings to regulate one or more of a brightness profile, wavelength emission profile,
pulse profile, and timing profile of the source of EM radiation. In an example, the
controller can control, set or drive the emission settings of the source of EM radiation.
[0018] Figure 1 is a schematic representation of a projectile according to an example. Projectile
100 comprises a source of EM radiation 101, such as an LED, laser diode, or multiple
LEDs or laser diodes. The source 101 is arranged to emit from the rear (i.e., the
trailing end) 103 of the projectile 100. The source 101 is communicatively coupled
to a controller 105. The controller 105 can receive data 107 from an external source
109. Data 107 received by controller 105 can be used to select and/or apply emission
settings for the source 101. That is, the data 105 can comprise an emission profile
that defines one or more emission characteristics of the source 101. For example,
an emission colour, length of time for emission, pulse rate and so on. The controller
105 can use the data 105 representing the emission profile to determine a set of emission
settings for the source 101. For example, the controller 105 can map the emission
settings to one or more commands (e.g., using a look up table) used to control or
drive the output of the source 101 in order to enable its output to be regulated according
to the emission profile. So, for example, if an emission profile is received that
requires the source 101 to output at full power for 10s, the controller 105 can use
this information to determine a power setting for the source 105 (e.g., 100% power
output) for a given period of time (i.e., 10s). In an example, an emission profile
can comprise a set of instructions (e.g., in the form of a marked-up listing of emission
characteristics for the source). The instructions can be interpreted by the controller
105 in order to appropriately regulate or drive the output of the source 101.
[0019] A source 101 can comprise one or more LEDs. An LED can emit at a selected wavelength,
which can be in the visible or non-visible parts of the EM spectrum. Multiple LEDs
can emit at respective different wavelengths. Accordingly, an emission setting can
include selecting an emission wavelength, which may be switched over time in order
to vary the wavelength at which the source 101 emits. For example, source 101 may
comprise two LEDs, one of which is configured to emit EM radiation in the visible
part of the spectrum, the other of which is configured to emit infra-red. An emission
profile may call for emission of visible light (e.g., blue) from a first LED for a
predetermined time, followed by emission of infra-red from a second LED (at which
point emission from the first LED can cease for example).
[0020] According to an example, a brightness profile for source 101 defines a measure of
brightness over a preselected period of time. In order to regulate brightness, the
average output power of the source can be controlled by, e.g., pulsing a source on/off
so that, on average over a given period of time, a desired power level is output.
That is, the output of the source can be
pulse-width modulated (PWM).
[0021] A wavelength emission profile can define an emission wavelength of the source of
EM radiation over a preselected period of time. For example, a single source may be
capable of emitting EM radiation over multiple wavelength bands of the EM spectrum,
and it may therefore be possible to switch between emission bands. In an example,
where the source comprises multiple LEDs, at least some of the LEDs can be configured
to emit in different wavelength bands. Accordingly, it is possible to switch between
bands by turning an LED on/off as appropriate.
[0022] A pulse profile defines a regular or irregular series of emissions of the source
of EM radiation over a preselected period of time. A series of emissions can be random.
For example, a pulse profile can be defined by a set of random numbers that define
respective pulse durations (similarly, such a random sequence may be used to define
a series of brightness values and so on). Accordingly, given a set of random numbers,
generated computationally or using a physical method, between predetermined minimum
and maximum values, the set of values generated, which may be normalised, can be used
to provide a set of pulse durations. If a pseudorandom number generator, for example,
is seeded with a known seed value, the set of pulse durations can be known and thus
reproducible to a user of the system but not known to other observers. That is, since
the pseudorandom number generator's number sequence is determined by the seed, a generator
can be reinitialized with the same seed in order to produce the same sequence of numbers.
Thus, the output of a source according to an example can be determined by a user,
but remain unknown to other observers. This can be used to enable the user to determine
the authenticity of a projectile for example, and may be used to prevent spoofing
or jamming. A random pulse profile can therefore be validated using the known seed
in order to verify the authenticity of the projectile.
[0023] In an example, a pulse profile can be synchronised with a detection system. For example,
given a known pulse profile (e.g., comprising a set of pulses of predefined durations
and intervals), a detector can be synchronised in order to detect only at the times
that the source is configured to emit. This can help to prevent jamming of a detector
by observers, for example, since the intervals within which malicious signals may
be detected by the detector is reduced.
[0024] In an example, a pulse profile can be used as a communication mechanism. For example,
a set of pulses emitted from the source can form a data stream. The data stream can
comprise, for example, a projectile identification, which may be used to validate
the authenticity of the projectile. Other information may be conveyed using this method.
Similarly, data may be conveyed using a brightness profile of the source such that
different brightness levels emitted map to different data bits for example.
[0025] Various different combinations for the emission characteristics described above are
possible. For example, an emission profile may call for brightness to vary over a
particular time period in combination with pulsing and wavelength changes. That is,
an emission profile can comprise a combination of multiple settings for a source.
Such combinations can be used to improve the detectability of the emissions by a user,
reduce the detectability of the emissions by a potentially hostile observer, serve
to reduce the likelihood of detection of the position of the user (from which the
projectile was fired for example), preserve battery life, communicate data, authenticate
a projectile, and so on.
[0026] Figure 2 is a schematic representation of a projectile according to example. In the
example of figure 2, data 107 is received for the external source over a physical
communications link 201 of the projectile 200. For example, projectile 200 can comprise
an interface, which may be a serial pr parallel interface, to enable e.g., duplex
communication between the external source 109 and the controller 105. Thus, controller
105 can receive data over the interface and may be able to transmit data over the
interface (e.g., in the form of a confirmation of receipt message, and/or a confirmation
of setting applied and so on). The physical link 201, forming the interface, may be
in the form of a plug socket or a set of electrical contacts for example.
[0027] Figure 3 is a schematic representation of a projectile according to example. In the
example of figure 3, data 107 is received for the external source over a wireless
communications link 301 of the projectile 300. For example, wireless link 301 of projectile
300 can comprise a radiofrequency (RF) communication module to enable short-range
RF communications to/from projectile 300 using, e.g., Bluetooth, Wi-Fi, near-field
communication (NFC), ultra-wideband (UWB) and so on. Thus, controller 105 can receive
data wirelessly over the wireless link 301 and may be able to transmit data over the
wireless link (e.g., in the form of a confirmation of receipt message, and/or a confirmation
of setting applied and so on, as described above). In the case of the projectile in
either of figures 2 or 3, emission settings can be applied using data received over
the corresponding communication system. In an example, a source may be used as a wireless
link. For example, exposure of a source to EM radiation can cause a current to be
generated therein, which can be detected by the controller. It is therefore possible
that the source can be used to provide data to the controller comprising a set of
instructions which can be used to trigger the controller to define the emission characteristics
of the source.
[0028] Transmission of data to projectile 200, 300 can occur using a device that it configured
to propel the projectile, e.g., a gun. For example, the device can comprise a wireless
or near-field module configured to interact with the wireless link 301 in order to
transmit/receive data. In the case of a physical link, a set of contacts of the device
(e.g., in a barrel or chamber thereof) can be used to interact with the projectile.
The contacts in the case of the physical link 201 may be circumferential contacts
around the projectile for example, thereby enabling easy connection with corresponding
contacts on the device. The converse may be used (i.e., circumferential contacts in,
e.g., barrel of gun etc.).
[0029] According to an example, a projectile as described herein can comprise a calibration
and/or test mode of operation. For example, at the point of manufacture, the functions
of a projectile comprising a system as described herein can be tested to ensure that
it operates correctly/within acceptable tolerances. Thus, a non-destructive test can
be performed in which source 101 is configured to emit in a predefined manner, such
as by way of a predefined number of pulses and/or brightness and/or wavelength and
so on. In this way, it is possible to test and confirm that the system of the projectile
is operating as expected. Such testing may occur in the field. For example, a signal
received by controller 105 can be used to trigger a test and/or calibration mode of
operation in which a particular set of emissions from the source, resulting from receipt
of the signal at the controller, can be used for the purposes of verification and/or
troubleshooting. For example, a sequence of pulses can indicate correct operation
or can define a fault code, which may be used to determine the cause of a fault.
[0030] Examples in the present disclosure can be provided as methods, systems or machine-readable
instructions, such as any combination of software, hardware, firmware or the like.
Such machine-readable instructions may be included on a computer readable storage
medium (including but not limited to disc storage, CD-ROM, optical storage, etc.)
having computer readable program codes therein or thereon.
[0031] The present disclosure is described with reference to flow charts and/or block diagrams
of the method, devices and systems according to examples of the present disclosure.
Although the flow diagrams described above show a specific order of execution, the
order of execution may differ from that which is depicted. Blocks described in relation
to one flow chart may be combined with those of another flow chart. In some examples,
some blocks of the flow diagrams may not be necessary and/or additional blocks may
be added. It shall be understood that each flow and/or block in the flow charts and/or
block diagrams, as well as combinations of the flows and/or diagrams in the flow charts
and/or block diagrams can be realized by machine readable instructions.
[0032] The machine-readable instructions may, for example, be executed by a general-purpose
computer, a special purpose computer, an embedded processor or processors of other
programmable data processing devices to realize the functions described in the description
and diagrams. In particular, a processor or processing apparatus may execute the machine-readable
instructions. Thus, modules of apparatus may be implemented by a processor executing
machine readable instructions stored in a memory, or a processor operating in accordance
with instructions embedded in logic circuitry. The term 'processor' is to be interpreted
broadly to include a CPU, processing unit, ASIC, logic unit, or programmable gate
set etc. The methods and modules may all be performed by a single processor or divided
amongst several processors.
[0033] Such machine-readable instructions may also be stored in a computer readable storage
that can guide the computer or other programmable data processing devices to operate
in a specific mode. For example, the instructions may be provided on a non-transitory
computer readable storage medium encoded with instructions, executable by a processor.
[0034] Such machine-readable instructions may also be loaded onto a computer or other programmable
data processing devices, so that the computer or other programmable data processing
devices perform a series of operations to produce computer-implemented processing,
thus the instructions executed on the computer or other programmable devices provide
a operation for realizing functions specified by flow(s) in the flow charts and/or
block(s) in the block diagrams.
[0035] Figure 4 is schematic representation of a controller according to an example. Controller
105 comprises a processor 401 and a memory 403 storing instructions 405. In an example,
controller 105 can be provided as part of a projectile, such as a projectile described
with reference to figure 1 to 3 for example. The instructions 405 are executable by
the processor 401. The memory 403 can store a look up table, which can be used to
map an emission profile to one or more emission settings. Controller 105 comprises
a driver 409. Driver 409 can be used to drive the output of a source. For example,
driver 409 can be used to supply power to source 101.
[0036] The instructions 405 can comprise instructions to receive data defining the emission
profile at a controller configured to control the output of the source of EM radiation,
and using the data, apply emission settings of the source of EM radiation at the controller;
map an emission profile to an emission setting; and, selectively energise one or more
of multiple sources of EM radiation, wherein the multiple sources of EM radiation
are configured to emit EM radiation at respective selected wavelengths.
[0037] Further, the teachings herein may be implemented in the form of a computer software
product, the computer software product being stored in a storage medium and comprising
a plurality of instructions for making a computer device implement the methods recited
in the examples of the present disclosure.
[0038] Although reference has been made herein to a projectile in the form of a non-incendiary
projectile, it is possible to use the methods and systems described herein to control
the output of an incendiary projectile. For example, the output of an electroluminescent
assembly can be controlled using the method described herein in order to modify its
emission profile.
1. A method for modifying the emission profile of a source of electromagnetic radiation
in a non-incendiary projectile, the method comprising:
receiving data defining the emission profile at a controller configured to control
the output of the source of EM radiation; and
using the data, applying emission settings of the source of EM radiation at the controller.
2. The method as claimed in claim 1, wherein the emission settings comprise at least
one of a: brightness profile, wavelength emission profile, pulse profile, and timing
profile.
3. The method as claimed in any preceding claim, wherein the source of EM radiation comprises
one or more LEDs and/or laser diodes.
4. The method as claimed in any preceding claim, further comprising:
applying the emission settings using the data over a physical communications link
to the projectile.
5. The method as claimed in any of claims I to 4, further comprising:
applying the emission settings using the data over a wireless communications link
to the projectile.
6. The method as claimed in claim 2 wherein the wavelength emission profile defines a
change in the emission wavelength of the source of EM radiation over a preselected
period of time.
7. The method as claimed in claim 6, further comprising selectively energising one or
more of multiple sources of EM radiation, wherein the multiple sources of EM radiation
are configured to emit EM radiation at respective selected wavelengths.
8. The method as claimed in any preceding claim, wherein the emission profile encodes
a data stream to be transmitted from the source.
9. The method as claimed in any preceding claim, wherein the emission profile defines
a randomly modulated emission characteristic of the source.
10. A projectile, comprising:
a source of electromagnetic radiation; and
a controller to receive data defining an emission profile;
the controller configured to regulate an output of the source of EM radiation using
the data, and apply emission settings for the source of EM radiation.
11. The projectile as claimed in claim 10, wherein the source of EM radiation comprises
one or more LEDs and/or laser diodes.
12. The projectile as claimed in claim 10 or 11, further comprising a wireless communications
link.
13. The projectile as claimed in any of claims 10 to 12, wherein the controller is configured
to regulate or drive the source of EM radiation according to the emission profile
by selectively energising the source of EM radiation.
14. The projectile as claimed in any of claims 10 to 13, further comprising an electrical
contact communicatively coupled to the controller, the contact disposed on or within
a portion of the surface of the projectile.
15. The projectile as claimed in claim 14, wherein the contact extends circumferentially
around the surface of the projectile.