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Claims  |
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What is claimed is:
1. Apparatus for counting each rotation of a projectile, after firing the
projectile from a firing weapon, the projectile having a longitudinal
axis, said apparatus comprising:
(a) counting means for counting each said rotation of the projectile as it
rotates around its longitudinal axis, the counting means comprising:
(i) spin signal means for generating a spin signal which varies over time
as the projectile rotates about its axis in the earths magnetic field and
where the magnitude of the spin signal reaches a predetermined threshold a
predetermined number of times for each said rotation of the projectile;
(ii) a counter operatively connected to the spin signal means for counting
the number of times the spin signal reaches its predetermined threshold;
(b) spin rate computation means for determining a spin rate of the
projectile, wherein the spin rate computation means is comprised of timing
means operatively connected to the counter for determining the time for
the projectile to rotate a predetermined number of times; and
(c) muzzle velocity computing means for determining actual muzzle velocity
based on a barrel pitch constant of the firing weapon and the spin rate of
the projectile.
2. The apparatus of claim 1 wherein the spin signal is sinusoidal and where
the predetermined threshold magnitude is zero, and where the zero
threshold is crossed twice for each complete rotation of the projectile
whereby each complete rotation generates one wavelength of the sinusoidal
spin signal.
3. The apparatus of claim 1 wherein the spin signal means comprises a
magnetic transducer including a conductive winding coil and a core through
which the earths magnetic field generates a time varying signal as the
projectile rotates.
4. The apparatus of claim 1 further comprising:
(a) detonation means; and
(b) receiver means for inductively receiving a turns-to-burst range
parameter prior to the projectile exiting the firing weapon, wherein the
turns-to-burst range parameter is based in part on a nominal muzzle
velocity parameter, and where the detonation means is activated when the
counter indicates that the projectile has rotated a number of times equal
to the turns-to-burst range parameter.
5. The apparatus of claim 4 further including adjustment computing means
for adjusting the turns-to-burst range parameter based on the actual
determined muzzle velocity, wherein the detonation means detonates the
projectile when the projectile has reached the adjusted turns-to-burst
range parameter, whereby the accuracy of the detonation is increased.
6. The apparatus of claim 5, wherein a time interval range parameter is
received by the receiving means in addition to the turns-to-burst range
parameter, and wherein the projectile utilizes the counter over a first
predetermined portion of the projectile trajectory and wherein the
projectile utilizes the time interval over a second predetermined portion
of the projectile trajectory.
7. The apparatus of claim 6 wherein the projectile utilizes the counter for
the first 1000 meters and utilizes the time interval thereafter until
projectile detonation.
8. A magnetic sensor system for use with a fuze of a projectile fired from
a gun where the projectile spins about its longitudinal axis, comprising:
(a) an inductive transmitter;
(b) a receiver inductively connected to the transmitter for receiving a
turns-to-burst turns count from the transmitter;
(c) spin signal means for generating a time changing spin signal based on
the projectile rotation in the earths magnetic field, conductively
connected to the receiver where the signal is sensed for each turn of the
projectile;
(d) counting means for counting the turns of the projectile operatively
connected to the spin signal means; and
(e) detonation means conductively connected to the counting means for
detonating the projectile when the turns-to-burst turn count has been
reached.
9. The sensor system of claim 8 further including computing means
operatively connected to the counting means for determining the actual
muzzle velocity of the projectile based on the turns counted and a barrel
pitch constant of the gun, wherein the computing means comprises a timer
connected to the counting means for determining the time for a projectile
to spin a predetermined number of times.
10. The sensor system of claim 9 further including compensating means
operatively connected to the computing means for adjusting the turns
count, which is based in part on a nominal assumed muzzle velocity, for
the difference between the nominal assumed muzzle velocity and the actual
muzzle velocity.
11. The sensor system of claim 9 wherein a time interval range parameter is
received by the receiver and further including time interval counting
means for storing the time interval range parameter which is operatively
connected to a timer such that the time interval counting means decrements
the time interval range parameter at a regular predetermined time interval
whereby the detonation means detonates the projectile when the time
interval range parameter has been decremented to zero.
12. The sensor system of claim 11 wherein the projectile utilizes the
counting means over a first predetermined portion of the projectile
trajectory and wherein the projectile utilizes the time interval range
parameter over a second predetermined portion of the projectile
trajectory.
13. The sensor system of claim 8 wherein the receiver receives a data
carrying signal and where the sensor system includes a capacitor
operatively connected to the receiver which is charged when the projectile
receives the data carrying signal and which is used to provide power for
the fuze after firing.
14. The sensor system of claim 8 further comprising a proximity sensor for
sensing ferrous objects a predetermined distance from the projectile
operatively connected to the detonation means for detonating the
projectile regardless of whether the turns to burst count has been
reached.
15. The sensor system of claim 8 further comprising an impact sensor
operatively connected to the detonation means for detonating the
projectile at impact with a target regardless of whether the turns to
burst count has been reached.
16. The sensor system of claim 15 further comprising delay means
operatively connected to the detonation means for delaying the detonation
of the projectile for a predetermined time period.
17. The sensor system of claim 15 further comprising ferrous detection
means for differentiating between a target which is substantially ferrous
and a target which is substantially non-ferrous, operatively connected to
the detonation means wherein the projectile detonates on impact if a
substantially ferrous target is detected and detonates after a
predetermined delay if a substantially non-ferrous target is detected.
18. A weapons system comprising:
(a) a projectile having a longitudinal axis;
(b) means for firing the projectile, the means causing the projectile to
spin around its longitudinal axis, where the projectile will spin a
predetermined number of turns per unit distance based on a barrel pitch
constant inherent to the means for firing;
(c) the projectile having a sensor through which the earths magnetic field
generates a voltage once the projectile exits the means for firing;
(d) projectile spin count means connected to the sensor for counting the
number of times the projectile spins around its longitudinal axis;
(e) detonation means for detonating the projectile when the projectile has
reached a predetermined spin count; and
(f) spin rate computation means for determining a spin rate of the
projectile, wherein the spin rate computation means is comprised of timing
means operatively connected to the projectile spin count means for
determining a time for the projectile to spin a predetermined number of
times.
19. The projectile of claim 18 further including computing means for
determining actual velocity based on the barrel pitch constant and the
spin rate of the projectile.
20. The projectile of claim 19 wherein the projectile includes receiver
means for inductively receiving a turns-to-burst range parameter prior to
the projectile exiting the means for firing, wherein the turns-to-burst
range parameter is based in part on a nominal velocity parameter.
21. The projectile of claim 20 further including computing means for
adjusting the turns-to-burst range parameter based on the actual
determined velocity, wherein the detonation means detonates the projectile
when the projectile has reached the adjusted turns-to-burst spin count,
whereby the accuracy of the detonation is increased.
22. The projectile of claim 21 wherein a time interval range parameter is
received by the receiving means in addition to the turns-to-burst range
parameter, and wherein the projectile utilizes the projectile spin count
over a first predetermined portion of the projectile trajectory and
wherein the projectile utilizes the time interval range parameter over a
second predetermined portion of the projectile trajectory.
23. The projectile of claim 22 wherein the projectile utilizes the
projectile spin count for the first 1000 meters and utilizes the time
interval range parameter thereafter until projectile detonation.
24. A method for determining the muzzle velocity of a projectile, after
firing the projectile from a firing weapon, the projectile having a
longitudinal axis, the steps comprising:
(a) counting each rotation of the projectile as it rotates around its
longitudinal axis, wherein the step of counting further includes
generating a spin signal which varies over time as the projectile rotates
about its axis in the earths magnetic field and where the spin signal
reaches a predetermined threshold a predetermined number of times for each
rotation of the projectile, whereby a rotation is counted when the spin
signal means reaches its threshold the predetermined number of times;
(b) computing a spin rate of the projectile, wherein the step of computing
the spin rate further comprises timing the time for the projectile to
rotate a predetermined number of times; and
(c) computing a muzzle velocity based on a barrel pitch constant of the
firing weapon and the spin rate of the projectile. |
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Claims |
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Description |
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FIELD OF THE INVENTION
This invention relates to the field of fuzes and more particularly, to an
apparatus and method for control of a projectile with fuze functions
including magnetically sensing ballistic spin parameters and computing
muzzle velocity for accurately controlling range to burst of a projectile.
BACKGROUND OF THE INVENTION
Remote settable fuzes have been used in projectiles for some time. A remote
settable fuze allows external information to be input to the projectile
before firing. One known method for inputting information to the fuze is
by non-contact inductive coupling. This is a transformer approach with the
primary of the transformer placed outside the projectile, in what is
commonly called a setter, and the secondary of the transformer placed in
the fuze. Magnetic flux passes between the primary and secondary with
appropriate AC modulation containing data. The information input to the
fuze relates to a fuze mode setting or for example, may contain a
time-to-burst for the projectile. Time-to-burst represents a predetermined
time period after firing, approximating a desired range, after which the
projectile detonates.
In a bursting munitions scenario, the most important features of the
projectile and its fuze are accuracy and safety to the user. These factors
are related to fuze control functions. Previously, systems have used
expensive and complicated mechanical and/or electrical methods to try to
more accurately determine the range of a projectile and control the fuze.
One variable which greatly affects the accuracy of the range determination
is the actual muzzle velocity, which can vary depending on a large number
of known factors. It has always been desirable to control the detonation
of a projectile based on a determination of actual muzzle velocity.
However, an accurate system for determining muzzle velocity within a
projectile has not been available. Systems mounted directly on the muzzle
of specialized guns do exist, but greatly complicate the gun and are
contrary to a general standardized approach for all weapons.
Prior systems have depended on time setting and have not been able to
accurately predict muzzle velocity. Other fuzing systems require
mechanical settings by the user for communicating functions. This
dependency on the operator creates a much larger risk of mistake or
accident. Other electronic systems have proved to be too costly and
require more space in the projectile than is available. Also, some prior
solutions use parts, such as crystals, which cannot readily tolerate the
forces or shock which the projectile experiences.
Consequently, a need remains for a compact, simple multi functional sensor
that acts as a remote receiver and provides more accurate detonation of
the projectile.
SUMMARY OF THE INVENTION
This invention is a sensor for a class of projectile fuzes for use in
artillery rounds, tank rounds, medium caliber bullets of all sizes, and
individually carried combat weapons. The functions inherent in this fuze
include those required by present standards and further include several
other functions not available with prior art fuzes and are all
accomplished with a single magnetic sensor element. In particular,
internal turns counting is provided so that a turns-to-burst detonation
mode is possible. The revolutions per second or turns of the projectile
are counted and the detonation of the projectile is based on this count.
Another related function of the invention is the determination of muzzle
velocity based on turns counting, which allows for calculation of what has
always been an indeterminate measurement. The determination of muzzle
velocity allows for compensation of the fire control systems count
estimate of the turns-to-burst, which is based on a nominal assumed muzzle
velocity, by modifying the turns-to-burst count based on the actual muzzle
velocity measurement.
The inventive sensor therefore functions as a remote set receiver, a
ballistic turns counter and a muzzle velocity calculator. The present
invention eliminates the previously mentioned problems and provides a
single sensor internal to the fuze to power the fuze, accurately sense
remote settings and modes, provide a count of ballistic turns to determine
muzzle velocity, and provide a multitude of functions which lead to
accurate and safe deployment of projectiles. The fuze can use the
measurement of the actual muzzle velocity to compensate the turns-to-burst
count for deviations of the actual muzzle velocity from the assumed
nominal muzzle velocity.
The invention comprises an apparatus for counting each rotation of a
projectile, after firing the projectile from a firing weapon, the
projectile having a longitudinal axis, the apparatus comprising counting
means for counting each rotation of the projectile as it rotates around
its longitudinal axis. The counting means further includes spin signal
means for generating a spin signal which varies over time as the
projectile rotates about its axis in the earth's magnetic field and where
the magnitude of the spin signal reaches a predetermined threshold a
predetermined number of times for each rotation of the projectile and a
counter operatively connected to the spin signal means for counting the
number of times the spin signal reaches its predetermined threshold.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a graph illustrating the velocity profile of a 25 mm projectile
over a range;
FIG. 2 is a graph illustrating the spin profile of a 25 mm projectile over
a range;
FIG. 3 is a cross section of a projectile which utilizes the invention;
FIG. 4 is a cross section of the nose element of a projectile showing the
nose fuze components of the invention;
FIG. 5 is a perspective view of the magnetic transducer of the invention;
FIG. 6 is a block diagram of the invention;
FIG. 7 is a block diagram of the algorithm for determining muzzle velocity;
and
FIG. 8 is a graph illustrating the power up and message period for the
invention.
DETAILED DESCRIPTION OF THE INVENTION
While this invention may be embodied in many different forms, there are
described in detail herein specific preferred embodiments of the
invention. This description is an exemplification of the principles of the
invention and is not intended to limit the invention to the particular
embodiments illustrated.
The bursting munition fuze can be categorized as the "remote control"
element of a weapons system. Once the projectile leaves the gun, the fuze
is the last control on the projectile's functions. Therefore, the fuze is
a vital performance link between the initial optimized attributes of the
gun and fire control subsystems and the ultimate maximization of the
warhead effects. As is well known, the fire control subsystem measures
target range, cant, wind, temperature, pressure, and target motion and
predicts a gun setting and subsequently communicates a burst range
prediction to the fuze based on calculated ballistic parameters.
The ultimate effectiveness of the weapon is directly related to control of
errors for the air burst prediction. A commonly employed approach is to
convert the target range (from the fire control rangefinder) into a time
countdown number based on estimated projectile ballistics. One of the
important ballistic characteristics is the nominal muzzle velocity for a
particular projectile and gun. A more accurate ballistic prediction could
be provided by basing the time countdown on an actual muzzle velocity
rather than relying solely on the nominal or assumed muzzle velocity for
that class of projectile and gun. The actual muzzle velocity changes with
propellant load, propellant density, propellant temperature, and barrel
wear and can result in range errors on the order of one hundred meters,
when using the nominal muzzle velocity parameter. This range error is
unacceptable.
A fuze cannot measure range directly and therefore uses a parameter
proportional to range. The prior art time-based measurement concept is
derived from the relationship of range being equal to velocity * time. As
shown in FIG. 1, for a typical 25 mm projectile, tested at 60.degree. F.
and with a nominal muzzle velocity of 617 m/s, the velocity versus range
is nonlinear. The curve shifts for different initial muzzle velocities,
producing large errors in time-based range prediction.
Alliant Techsystems has discovered analytically and experimentally that a
turns counting base parameter behaves more ideally (more linear) as shown
in FIG. 2, which was tested at 60.degree. F. and with a 6.degree. gun
twist. As will be discussed more fully below, Alliant Techsystems has
discovered that they can use the earth's magnetic field to count the turns
of the projectile. From the known gun characteristics and the turns count,
the instantaneous spin rate of the projectile can be calculated. The spin
profile (spin versus range) shown in FIG. 2 is for a 25 mm projectile and
is relatively linear and predictable, producing better prediction
performance than time interval measurement. Instantaneous spin rate is an
excellent base parameter estimator of a projectile's velocity over a good
part of its flight and especially near the muzzle. A turns counting fuze
can measure actual muzzle velocity, as will be discussed more fully below,
and provide a correction to the turns-to-burst count based on the
difference between the nominal and actual muzzle velocity, so that by
using down range turns counting it can produce minimal burst error.
Although the range determination can be based entirely on a turns count,
Alliant Techsystems has discovered that depending on specific ballistic
application and range it may be more accurate to utilize both turns
counting and time interval counting. For a given fixed muzzle velocity,
Alliant Techsystems has discovered that turns performance is much better
out to about 1000 m. After this point, the velocity tends toward a
terminal value and time performance is somewhat better. Therefore, it is
optimal to utilize a fuze having a sensor which continuously measures
turns and an algorithm to measure velocity based on turns counting in
conjunction with time interval counting. In this manner, a fuze system may
employ turns counting at the short and medium ranges, augmented by time
prediction at far ranges.
The fuze of the invention provides a unique approach to measure and correct
for muzzle velocity. The same sensor that provides for setter
communication measures spin rate at muzzle exit which is related to muzzle
velocity by barrel twist, as is well known. This same sensor can be used
to count turns down range, as the advance ratio is more accurate than time
over a significant early portion of total range. The advance ratio equals
the turns per unit distance of a projectile due to gun barrel rifling. The
sensor allows for real time assessment of muzzle velocity and subsequent
down range velocities. This sensor allows combining muzzle velocity,
turns, and time to accurately establish a range dependant burst.
The invention uses a magnetic circuit to communicate to the fuze. An
inductive setting coil is driven by the fire control electronics with a
receiving coil located in the fuze. The receiving coil is coupled to the
setting coil by transformer action. Data is modulated onto a carrier
signal. The carrier signal is rectified in the fuze and is used to charge
a capacitor for storage of fuze system power. The modulation with mode,
burst time, and other information is decoded and processed for operational
parameter definition.
As described above, the range to burst of a projectile is subject to errors
due to various factors. The fire control electronics of a weapon system
provide nominal data based on a calculated range to burst or time to burst
to the fuze. This data is only as accurate as the projectile
characteristics are close to the nominal settings, one of which is the
nominal muzzle velocity. Therefore, it is desirable to adjust the range to
burst based on actual measurement of the muzzle velocity.
In order to determine muzzle velocity a sensor is employed to count the
turns of the projectile. Full or partial turns may be counted, as desired.
The sensor is a magnetic transducer which senses the earth's magnetic
field. As will be discussed more fully below, based on the characteristics
of the gun, spin rate can be determined after a predetermined number of
spins have been counted. Spin rate is proportional to muzzle velocity. In
this manner, muzzle velocity is determined.
Once muzzle velocity has been determined, the range to burst of the
projectile may be adjusted to compensate for a muzzle velocity which is
not equal to the nominal value. If the fuze is programmed to detonate
after a number of counted turns, the calculated muzzle velocity is
compared to the nominal velocity value and the number of turns to burst is
adjusted upward or downward to compensate for any variation in velocity.
If the measured muzzle velocity is greater than the nominal then the
number of turns to burst is decreased to reduce error. If the measured
velocity is less than the nominal then the number of turns to burst is
increased to reduce error.
Referring to FIG. 3, a cross section of a projectile 5 is shown. The
projectile 5 includes a base element 10, a warhead 12 and a nose element
14. The projectile 5 also contains a fuze 16 (shown in FIG. 4) in the nose
element 14 and/or the base element 10. One skilled in the art knows that
the fuze may be "packaged" to fit in the nose element 14 and may also be
"packaged" to fit in both the nose and base elements 14 and 10, as
desired.
FIG. 4 shows the nose element 14 of FIG. 3 with a fuze 16. FIG. 4 shows the
electronics 18 of the fuze 16 which are necessary for operation, which are
well known in the art. In this preferred embodiment, two annular
electronics portions are shown, as are well known in the art. This drawing
is used to show an example of a fuze layout. Many other configurations of
the fuze 16 are known and may be utilized within the spirit of the
invention.
Referring to FIG. 5, the fuze 16 also includes a magnetic transducer 20.
The magnetic transducer includes a single coil 22, a shaped core 24 and a
magnet 26. This magnetic transducer 20 receives data from the remote
setter (best seen in FIG. 6) and also senses the earth's magnetic field to
count turns of the projectile. The inherent axial sensitivity of the coil
22 acts as the receiver for the AC remote set communication waveform (best
seen in FIG. 8), introducing both power and data to the fuze. The
cylindrical magnet portion 26 of the transducer 20 provides transformer
coupling with the setter coil located in block 32 of FIG. 6.
The shape of the transducer core 24 establishes an output signal from coil
22 as the core 24 rotates around its longitudinal axis in an external
homogeneous field. When the earth's magnetic field is perpendicular to the
spin axis (radial field), the tab-like portions 25 of the core causes
magnetic flux to alternate in direction through the coil thereby producing
a sine wave voltage. As the alignment angle between the spin axis and the
earth's field vector direction changes, the sine wave voltage amplitude
decreases with the cosine of the angle. One skilled in the art will
recognize that the tabs 25 may be of different shape and size than shown,
but still produce the alternating flux path as described herein. Further,
the size of the transducer can be adjusted for rounds of different
caliber.
The core 24 gives the coil radial sensitivity, allowing monitoring of the
earth's field as the projectile spins. The spin signal is in the form of a
sine wave. One complete sine wave represents one turn of the projectile. A
voltage is generated by the magnetic transducer 20 sensing the
time-changing magnetic field of the earth due to projectile spin. The
voltage amplitude increases until it peaks at a quarter turn of the
projectile and then decreases to zero at the half turn point. The voltage
then reverses direction and the amplitude increases to the three quarters
turn point and then decreases to zero when one complete turn has been
made. Therefore, the zero crossings can be counted. Each turn of the
projectile is represented by two zero crossings. One skilled in the art
will recognize that known engineering methods may be utilized to count
partial turns of the projectile so that the turns count may count quarters
of a turn or a partial turn. The spin signal allows for a determination of
muzzle velocity as will be described below. The spin signal continues for
the total life of the flight of the projectile and provides a means to
accumulate a turns count as the basis for air burst prediction in place
of, or in conjunction with a time prediction. Although a search coil
magnetometer has been described herein, it should be understood that other
magnetometers may be utilized.
Referring to FIG. 6, a block diagram of a weapons system including the
invention is shown. Block 30 represents the Fire Control System of a gun
(not shown) which fires the projectile 5 including the fuzing system of
the invention. The fire control system 30 is attached to or is an integral
part of the gun and includes appropriate well known circuitry and
processors for measuring the range to target of the projectile as desired
by an operator. The fire control system 30 also computes the time to burst
or turns to burst for the particular projectile based on the target
selected by the operator and the known ballistic characteristics of the
gun. Fire control systems are known in the art and provide numerous
functions and information. The turns to burst count is derived from
ballistic characteristics, other parameters and modeling which are known
to those skilled in the art. Although derived in the past, the turns to
burst count has not been utilized because no known method existed to count
the turns of the projectile during flight. The above are provided as
examples to explain the invention and should not be considered as
limitations of the invention.
Block 32 represents the remote setter or fuze setter.. This device is known
in the art and provides for power-up of the fuze and also transmits the
necessary information from the operator to the fuze. The fuze setter 32 is
conductively connected to the fire control system 30 in the preferred
embodiment. The remote setter 32 may be a remote unit hand held by the
user or may be attached to the gun or an integral part of the gun. The
fuze setter 32 accesses every round during the gun cycle to provide all
communication functions to the fuze 10. The setter 32 is designed to
allocate a period while the projectile is in the ram or pre-chamber
position for communication. Each round receives the necessary exposure
while the previous round is being fired.
A typical setter 32 includes two coils (not shown) arranged so as to be
closely coupled to the fuze nose element while the round is in the ram
position. The coils are arranged to additively drive their leakage flux
(flux outside the setter's coils) down the axis of the nose element 14 of
the projectile 5 to the magnetic transducer 20. The setter 32 is
inductively coupled to the fuze 10 of the projectile 5 and acts as a
transmitter. The setter 32 must communicate information to the fuze 10. At
a minimum, the information for a bursting round will contain a parameter
representing range, i.e. turns to burst, time interval or a combination of
both. The setter 32 may also pass information including mode settings and
error compensation data. In this manner, a variety of functions or modes
can be selected or prioritized individually in each round.
The communication is shown in FIG. 8 where the power-up and message period
communicated to each fuze 16 from the setter 32 is depicted. The magnetic
waveform received at the magnetic sensor 20 is a large peak to peak
signal, in the preferred embodiment 40-50 volts in amplitude. The
relatively high voltage allows for high energy storage on a capacitor 36
(shown in FIG. 6) and is also used to charge another capacitor 38 (shown
in FIG. 6) in the base element specifically reserved for firing the
detonator. The detonator capacitor 38 conserves fuze reliability in cases
where the power storage capacitor 36 drains too low. By this means, all
fuze electronic circuits are individually powered.
Simultaneous with the storage of fuze power is the communication of
calibration data and parameter data. An initial preamble of an accurate
burst of 10 Khz is modulated at the beginning of the waveform to create a
start signal, and is used in the fuze to quick-lock its own internal time
base to the accurate 10 kHz standard from the fire control electronics 30.
Therefore, any algorithms or parameter measurements requiring accurate
timing are available in the fuze electronics without an accurate internal
time-base reference.
Following the 10 kHz preamble are frequency shift modulated signals of 7
kHz or 13 kHz referenced to the 10 kHz which represent digital (bits) 1's
and 0's. Up to twenty bits can be communicated to the fuze 16 in this
message format to include data for burst, error compensation direction and
mode settings, and time delays if desired. Eleven bits will allow
parameter measurement to an accuracy greater than 0.1% and 9 bits remain
for other functionality and future growth. It should be understood that
the frequencies used for the preamble and to represent 1's and 0's, as
well as the number of bits transmitted can be varied as desired.
The magnetic transducer configuration 20 serves several functions and
allows for several functions to be performed within the fuze 16 without
specific on-axis positioning. The magnetic transducer 20 acts as a
receiver where information is inductively communicated to the fuze 10.
Referring again to FIG. 6, the power storage and supply 34 of the fuze is
shown. The fuze 10 must have a power supply 34 to function. The inductive
coupling of the transducer 20 to the fuze setter 32 allows large voltages
to be transferred from the setter to the fuze 10, as discussed above. In
this manner, the fuze 10 is powered.
Referring to FIG. 7, a top level algorithm of the invention is depicted.
FIGS. 7 and 6 will be discussed in tandem. Block 40 represents the step of
utilizing the fire control system 30 to measure target range. The time to
burst or turns to burst or both are calculated based on nominal assumed
gun and projectile parameters. Block 42 represents the step of
communicating data including | | |
