U.S. patent number 3,803,974 [Application Number 05/303,501] was granted by the patent office on 1974-04-16 for fire control system.
This patent grant is currently assigned to William Wahl Corporation. Invention is credited to Charles E. Everest, Henry P. Voznick.
United States Patent |
3,803,974 |
Everest , et al. |
April 16, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
FIRE CONTROL SYSTEM
Abstract
A fire control system that can be readily installed with minimum
change on existing aircraft, actually tests all weapon positions
and stores a number of status words representing the current state
of the various weapon positions. Upon occurence of a selected
number of firing conditions such as firing interval, remaining
quantity of a salvo to be fired and the fire command, the system
will automatically extract from the store of weapon status words,
one word corresponding to an unfired weapon of selected type. The
extracted word is automatically sent to the weapon firing station
in a time division multiplexing arrangement that shares a single
communication channel among fire command, test command and sensed
status words. Although the system will automatically select an
unfired weapon of a chosen type, the pilot is provided with a
complete display of status of all weapons and a remaining stores
display indicating the total remaining weapons of the respective
types. Comparison of a commanded word with the actual status of a
given weapon position is employed to provide the pilot with a hung
ordnance alarm.
Inventors: |
Everest; Charles E. (La Habra,
CA), Voznick; Henry P. (Arcadia, CA) |
Assignee: |
William Wahl Corporation (Los
Angeles, CA)
|
Family
ID: |
23172406 |
Appl.
No.: |
05/303,501 |
Filed: |
November 3, 1972 |
Current U.S.
Class: |
89/1.56;
89/37.16; 340/3.71; 340/3.43 |
Current CPC
Class: |
B64D
7/00 (20130101); H04Q 9/14 (20130101); F41A
31/00 (20130101) |
Current International
Class: |
F41A
31/00 (20060101); B64D 7/00 (20060101); H04Q
9/14 (20060101); F41f 003/06 (); H04q 009/14 () |
Field of
Search: |
;89/1.5E,1.814,37.5R,4P
;340/147R,163 ;343/6.5R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bentley; Stephen C.
Attorney, Agent or Firm: Gausewitz, Carr &
Rothenberg
Claims
What is claimed is:
1. In a system having a plurality of weapon stations and at least
one multistate weapon device at each station,
A. means for testing said devices to detect the state thereof,
B. means responsive to said testing means for generating status
words each including information denoting the state of one of said
devices,
C. storage means responsive to said status word generator for
storing said status words,
D. means for extracting from said storage means a status word
corresponding to one of said devices having a preselected state,
and
E. means responsive to said extracted status word for actuating
said one device to change its state.
2. The system of claim 1 including means for including in each
status word information designating a classification of the device
whose state is denoted thereby, said means for extracting a status
word from said storage means including means for extracting words
corresponding to devices of a selected classification and selected
state.
3. A control system for changing the state of one or more of a
group of multistate aircraft weapon devices, said control system
comprising
A. a remote station including
1. actuator means for effecting a change of state of one of said
devices,
2. state sensor means for sensing the states of said devices and
transmitting status words each including a representation of the
sensed state of a device,
B. a command station comprising
1. sensor command means for generating test words,
2. means for transmitting said test words to said state sensor
means to actuate said sensor means and cause transmission of said
status words,
3. a command status memory for receiving and storing status words
transmitted from said state sensor means,
4. means for selecting a word having a predetermined state from
said command status memory, and reading out the selected word as an
actuator word, and
5. means for transmitting said actuator word to said state change
actuator means to effect a change of state of one or more of said
multistate devices.
4. The control system of claim 3 wherein said command station
includes means for establishing a state change command
prerequisite, and wherein said means for reading out a selected
word includes means responsive to both said means for selecting a
word and to said means for establishing a prerequisite.
5. The system of claim 3 wherein each said actuator word, test word
and status word includes an address identifying a unique one or
group of said multistate devices, and wherein said remote station
includes means for identifying a unique address in each transmitted
actuator and test word and for controlling state change or state
sensing respectively of the device or group of devices uniquely
identified by the actuator or test word address.
6. The system of claim 5 including a single communication channel
interconnecting said remote station and said command station, and
wherein at least a group of said words is transmitted between said
command and remote stations along said single communication
channel.
7. The system of claim 6 wherein all of said actuator words are
transmitted to said remote station through said single channel of
communication.
8. The control system of claim 6 wherein all of said test words are
transmitted to said remote station through said single channel of
communication.
9. The control system of claim 6 wherein all of said status words
are transmitted from said remote station through said single
channel of communication.
10. The control system of claim 6 wherein said single channel of
communication comprises a single electrical current path
interconnecting said remote and command stations.
11. The control system of claim 3 wherein said remote station
comprises a plurality of remote substations each having a
transceiver and each having a plurality of multistate devices of a
predetermined type, each remote substation transceiver comprising a
state change actuator means for changing the state of a selected
device at the associated remote substation and state sensor means
for sensing the state of selected devices at the associated remote
substation, each said transceiver further including means for
identifying a unique address contained in an actuator or test word
that uniquely identifies the associated remote substation and
selecting and uniquely identifying one of the devices at said
substation that is uniquely identified by the actuator or test
word.
12. The control system of claim 11 wherein each transceiver
includes means for including in each status word generated thereby
a type code uniquely identifying fixed characteristics of devices
at the associated substation, and wherein said status selection
means at said command station includes means for selecting from
said command status memory a word having a preselected type code,
whereby devices of a particular type may be selected for
actuation.
13. The system of claim 12 wherein said command status memory
includes priority override means for selecting a word from said
command status memory which word has an address code identifying a
unique address of a unique remote substation, said priority
override means including means for overriding operation of said
type code selecting means.
14. The control system of claim 11 wherein said command station
includes means responsive to status words transmitted from said
remote stations for providing a display of the state of each of a
plurality of said devices.
15. The apparatus of claim 11 including a command actuator memory
for storing actuator words transmitted from said command status
memory, and means responsive to status words transmitted from said
remote station for comparing the state of said multistate devices
with the state of devices whose state is commanded to be changed by
actuator words transmitted from said command status memory, and
means responsive to said means for comparing for providing a
failure to actuate signal that indicates one of said devices has
failed to properly change its state in response to a change of
state command embodied in an actuator word transmitted from said
command status memory.
16. The control system of claim 11 wherein said command station
includes means for establishing state change prerequisites, and
wherein said means for reading out a selected word includes means
responsive to both said means for selecting a word and to said
means for establishing prerequisites.
17. The control system of claim 16 wherein said remote stations are
armanent stations of an aircraft and wherein said multistate weapon
devices are ordnance devices each having an active state in which
state the ordnance may be fired and having an expended state that
exists after firing of the ordnance, wherein said command station
is accessible to the pilot of the aircraft, and wherein at least a
plurality of said state change prerequisites may be manually
established by the aircraft pilot, and wherein one of said state
change command prerequisites is a pickle signal that commands
firing.
18. The control system of claim 17 wherein said state change
command prerequisites comprise at least one of the following
conditions
A. a predetermined timed interval has elapsed since the previous
firing,
B. a predetermined quantity of ordnance has not been fired since
the beginning of a presently command salvo of firing,
C. an ordnance of a preselected type exists in an active state at
one of said remote substations,
D. an ordnance exists in an active state at a preselected position
of a preselected substation,
E. a pickle signal exists.
19. The control system of claim 18 including means responsive to
said command status memory for providing a display of quantities of
ordnance of different type remaining in active state at said remote
stations.
20. The control system of claim 5 wherein each said actuator word
includes an actuator pulse, and wherein each state change actuator
includes means for transmitting said pulse to effect a change of
state for one of said devices identified by the actuator word
address.
21. The control system of claim 5 wherein each said actuator word
includes an actuator function code and an actuator pulse and
wherein each state change actuator includes decoder means for
recognizing said actuator function code and means responsive to
said decoder means for transmitting said actuator pulse to effect
change of state of one of said devices identified by the actuator
word address.
22. The control system of claim 5 including timing means for
controlling said sensor command means and said command status
memory, said timing means including means for disabling reading
from said command status memory during a period including the
transmittal of a test word from said command station and during the
subsequent transmittal of a status word in response to such test
word.
23. The control system of claim 22 wherein said timing means
includes means for transmitting a plurality of test words during
said period, and receiving at said command station a plurality of
status words in response to respective ones of said transmitted
test words, said command status memory including means for writing
said plurality of status words therein during said period.
24. A weapon control system comprising
A. a command station comprising means for transmitting a data word
having information coded therein in the form of data bits,
B. a communication channel connected at one point to receive data
words transmitted from said command station, and
C. a remote weapon station connected to another point of said
communication channel to receive data words transmitted from said
command station, said remote station including
1. means for processing information contained in a data word
received by said remote station, and
2. power supply means for supplying energizing power to said
information processing means, said power supply means
comprising
a. storage means responsive to data words received from said
communication channel for storing electrical energy contained in
said data words, and
b. means responsive to said storage means for supplying said
electrical energy from said storage means to said means for
processing information.
25. The control system of claim 24 wherein said remote station
includes a plurality of substations, wherein each said data word
includes an address unique to at least a given one of said remote
substations, wherein each said substation includes recognition
means for recognizing a unique address code in a received data word
and for providing a station identification signal and wherein said
storage means includes means for supplying electrical energy to
said station address recognition means.
26. The control station of claim 25 wherein at least one of said
substations includes a weapon device adapted to be actuated by an
actuator signal and wherein said command station includes means for
sending an actuator signal through said communication channel in
sequence with a transmitted data word, said information processing
means including means for enabling said device at said one
substation so that it may be actuated by an actuator signal
received by said one remote substation.
27. The control system of claim 26 wherein the amplitude of said
actuator signal transmitted through said communication channel is
substantially equal to the amplitude of the data word pulses
transmitted through said communication channel, each said
substation including means for attenuation received data word
pulses, whereby an actuator signal having a relatively high energy
level is fed to actuate said divice and data pulses of relatively
low energy level are received by said transceiver data processing
means and said transceiver power storage means.
28. The method of selectively changing the states of a plurality of
multistate weapon devices at a remote station comprising the steps
of
A. sending a plurality of test words to each of said remote
stations through a communication channel, each said test word
including a station address and a test function code,
B. receiving each test word at each remote station and enabling a
particular one or more of said stations identified by the test word
address code,
C. determining the state of a device at a station enabled by an
identified address code in response to a received test word test
function code, and transmitting from such station through said
communication channel a status word including an address unique to
such transmitting station, said status word also including a status
code representing sensed state of the device at the station enabled
by the address code,
D. storing status words from said remote stations in a command
status memory,
E. extracting from said command status memory a status word having
an address code, an actuate function code and a preselected status
code,
F. transmitting said extracted status word through said
communication channel to said remote stations, and
G. changing the state of a device at one of said remote stations in
response to receipt of a transmitted status word having the address
code of such station.
29. The method of claim 28 including the step of transmitting an
actuator signal through said communication channel after
transmission of a status word extracted from said command status
memory, and employing said actuator signal to change the state of a
device at the station whose address is identified by the address
code of the command status word received by such station.
30. An armament information and control system comprising
A. a command station comprising
1. a test word generator for generating said transmitting a
plurality of test words each having an address code and a test
function code,
2. a command status memory for receiving and storing status words
each having an address code and a device status code,
3. command enable means for extracting a status word from said
command status memory having a preselected device status code, said
extracted status word comprising a command word,
4. means for transmitting said extracted command word from said
command station,
B. a plurality of remote stations each including
1. means for receiving a command word transmitted from said command
station,
2. a multistate weapon device,
3. station identification means for recognizing the address code of
a command word received by the remote station,
4. actuator means for effecting a change of state of the
device,
5. sensor means for determining the state of the device,
6. function decoding means for selectively enabling the actuator
and sensor means,
7. means for enabling said remote substation in response to said
station identification means,
8. means responsive to said sensor means for assembling a status
word including an address code and a status code representing the
state of the device,
9. means for transmitting the status word from said remote station
to said command station,
C. a communication channel connecting said command station with all
of said remote stations, each said test word and command word being
transmitted from said command station to all of said remote
stations through said communication channel and each said status
word being transmitted from respective remote stations to said
command station through said communication channel.
31. The system of claim 30 wherein said command station includes
timing means for causing said test word generator to transmit a
plurality of test words one after the other and for causing a
status word transmitted from a remote station to be entered into
said command status memory after each test word is transmitted from
said command station, said timing means including means for causing
the test words transmitted from said command station through said
communication channel to alternate with status words transmitted
from said remote stations through said communication channel.
32. The control system of claim 31 wherein said command station
includes means for generating an actuate pulse after the extraction
from said command status memory of a predetermined number of
command words, and means for transmitting said actuate pulse to
said remote stations after transmittal of said predetermined number
of command words.
33. The control system of claim 32 wherein said command station
includes means for displaying the status of devices at each of at
least a group of said remote substations.
34. The control system of claim 33 wherein said command station
includes means for storing command words extracted from said
command status memory for transmission from said command station,
and means for comparing
a. the status of devices at said remote stations, as represented by
said status words transmitted from said remote stations after
transmission of a command word with
b. the status of the device represented by such extracted command
word, thereby indicates whether or not the commanded change of
state occurred.
35. The control system of claim 33 including means for counting and
storing the total of all words in the command status memory having
a preselected status.
36. The control system of claim 31 wherein each said remote station
includes energy storage means for receiving and storing electrical
energy contained in said command word test words transmitted from
said command station through said communication channel, said
remote station actuator means, sensor means, station identification
means, decoding means, and status word assembler means, each
comprising electronic circuits, said power storage means including
means for providing operating power to at least one of said
electronic circuits of the remote station.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to control systems for testing and
operating devices at a number of stations and more particularly
concerns methods and apparatus for testing devices to be actuated
and employing information obtained from such testing to select
certain of the tested devices for actuation.
2. Description of the Prior Art
Various types of remote control operating systems require the
remote operation of numbers of different devices of different types
at selected stations according to preselected conditions. The
greater the number of stations and variety of devices to be
operated, the more complex the system and the more difficult it
becomes to achieve error-free selective operation. In present-day
military tactical aircraft, for example, a number of different
types of ordnance are carried and these must be selectively fired
by the aircraft pilot while he is occupied with control of the
flight of the aircraft itself. Many problems exist in control of
such complex aircraft weapon systems. For example, release devices
for bombs, munitions and rocket dispensers in many cases do not
provide proper execution of the pilot's command. This may be due to
intervalometer malfunction, circuit interruption or a combination
resulting from shock and vibration environment on the aircraft wing
where the weapons are carried. Further, present cockpit weapons
control panels do not provide information for the pilot concerning
actual weapon status. Hung ordnance, that is, a weapon that has
been commanded to fire but the firing of which has not been carried
out, is not identified in present systems.
Various systems have been suggested to provide increased quantity
of weapon information display and facility of pilot control of
groups of weapons. Such systems are exemplified by the U.S. Pat.
No. 3,499,363 to M. J. Lauro, and U.S. Pat. No. 3,598,015 to
Delistovich et al. These systems, for example, provide a display of
weapon inventory, but this display is simply a record of commanded
fire pulses and not a display of actual weapon status. Thus, as
previously indicated, even though the firing of a weapon has been
commanded, such firing may not necessarily be carried out due to
various types of malfunctions to which such aircraft fire control
systems are notoriously subject. Although the systems suggested in
these patents provide increased quantities of weapon information
displayed, there is no actual testing of existing weapons and no
selection of a weapon for firing based upon an actual active state
of a weapon of known type at a given position. Two-way
communication between the pilot and the weapons has not been
provided. Only a feedback from the weapon positions can provide
true and accurate weapon status information.
At present, the Air Force has nearly 100 different munitions that
may be dispensed in tactical operations. There are many ways to
arm, disarm, fire or jettison these devices. Some are fired by
triggering a present intervalometer as in the case of a 2.75 inch
rocket, a settable intervalometer as in the case of a SUU-13
dispenser, or dropable by a single release as in the case of bombs
or missiles. There are also several kinds of racks used. The
multiple ejection rocket racks employ secondary steppers of fixed
programming. This variety requires the pilot, among his other
tasks, to remember what weapon is set where and how it will
operate. He may fire or use a particular ordnance but has no return
signal to tell him positively what is the ordnance status on his
aircraft. Further, accuracy of dispensed ordnance varies with the
particular weapon and type of timing or release method.
Accordingly, it is an object of the present invention to provide
the pilot of an aircraft with two-way communication with the
ordnance on the wing and to allow him to select a weapon or weapon
type based upon actual sensed weapon status.
Another object of the invention is to prevent inadvertent weapon
firing, employing a novel digital code arming system to provide
increased safety against accidental firing and radiation
hazards.
Still another object of the invention is to provide an improved
information and control system that may be readily installed in
existing aircraft and employs a minimum of wiring for communication
between the pilot and the weapon stations.
SUMMARY OF THE INVENTION
In carrying out principles of the present invention in accordance
with a preferred embodiment thereof, actuatable devices at a number
of remote stations are tested and test results stored in a status
memory. Based upon the stored test results, a particular device to
be actuated is automatically selected and an actuating command
signal sent to achieve such actuation. According to other features
of the invention, means are provided to select devices for
actuation according to either position or type and to achieve such
actuation only upon the occurence of certain preselected
conditions. Various displays and inventories of device status are
provided. Failure to execute a commanded actuation may be detected.
The arrangement is achieved by means of a time sharing of a
communication channel between a command station and remote
stations, and data words sent from the command station are employed
not only for their information content but also for their
electrical energy content to provide power for the data processing
that is carried out in the remote stations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a broad functional diagram of a method and apparatus for
remote operation embodying principles of the present invention.
FIG. 2 illustrates a system according to the present invention
applied to a tactical aircraft.
FIG. 3 comprises a broad functional block diagram of the aircraft
system of FIG. 2.
FIG. 4 is a block diagram of a typical remote station and its
transceiver in the system of FIG. 3.
FIGS. 5a through 5e collectively comprise a detailed electrical
diagram of the command station shown in FIG. 3.
FIG. 6 is a detailed electrical diagram of a typical
transceiver.
DETAILED DESCRIPTION
1. General System
Illustrated in FIG. 1 is a functional block diagram of certain
significant aspects of the testing and device actuation of the
present invention. One or a number of operating stations each
contains one or a group of multistate devices 10, which may be any
one of a number of different classes of apparatus that are capable
of assuming at least two different states or conditions and that
can be changed from one of such states or conditions to another. An
example of such devices to be described more particularly
hereinafter in connection with an embodiment of the invention
designed for an aircraft fire control system, may be ordnance
devices having firing relays or firing squibs which assume one
state, an active state, before they are fired and which may be
actuated to launch a rocket or drop a bomb, thereby assuming a
second state, an expended state.
Also located at the operating station is a transceiver including a
state-change actuator 12 and a state sensor 14. The state-change
actuator of the transceiver is arranged to receive an actuator word
having an address that identifies a unique operating station and a
unique one of the multistate devices. Also included in the actuator
word is an actuator (fire) signal that causes the identified device
to change its state under command of the actuator word.
The state sensor 14 receives and responds to a test word
transmitted from the command station or from some other test
station. The test word also uniquely identifies a given station and
unique device and causes the state sensor to sense the state of the
device so identified. Having sensed the device state, the state
sensor assembles a status word that identifies the particular
device and includes a status code representing the state of the
device. If deemed necessary or desirable, the status word may also
include an identification of a fixed characteristic or
classification of the identified device. That is, the status word
may identify the particular device weapon type, for example, such
as rocket, bomb, flare, etc.
The test words for the several devices are generated and
transmitted to the state sensor from a state sensor command 16. The
status words assembled by the state sensor 14 are transmitted for
storage in a command status memory 18. In one form of testing
sequence, the sensor command 16 generates and transmits a series of
test words, each of which uniquely identifies a different one of
the devices to be tested and, each of which is transmitted to the
several state sensors, one after the other. In such an arrangement,
it is convenient to space the transmission of successive test words
so that the corresponding status words assembled by the addressed
state sensor may be transmitted from the operating station to
command station between transmission of successive test words from
the sensor command. With such an arrangement, of course, one may
employ a single communication channel for propagating test and
status words, time sharing the single channel. The sensor command
may operate periodically, going through one or several full cycles
of testing all of the multistate devices and storing corresponding
status words in the command status memory and thereafter stopping
operation for an interval. Alternatively, the system may be
arranged to afford continuous testing so that each full cycle of
testing all of the multistate devices is immediately followed by a
repeated full cycle of testing. In the latter situation, testing is
interrupted only to command a change of state and the command
status memory is continually updated so that its contents are
always current.
Since one of the multistate devices is to be changed from one state
to another, and since several of the states are different, it is
desirable to command a change of state of only those devices that
exhibit a predetermined condition. For example, it will be desired
to send a change of state signal namely, a fire signal, only to
those weapons or weapon positions that have not yet been fired.
Accordingly, such a unique state is selected in a status selection
circuit 20 and caused to extract from the command status memory, a
given status word (from the totality of status words stored
therein) that uniquely addresses one of the multistate devices
which is known to have a selected state. The status word extracted
from the memory 18 is employed as the actuator word that is
transmitted to the operating station for address identification and
state change actuation by the actuator 12.
In most operating systems, it is necessary that certain conditions
occur before an operation or actuation may take place. Thus, a
status change command prerequisite circuit 22 is employed to enable
the extraction of a selected actuator word from the command status
memory. The command prerequisite circuit 22 may sense any one or
group of command prerequisites such as, for example, the interval
between successive actuations, the total number of actuations in a
given period or in a given group or salvo, and the presence of a
command actuation signal. Obviously, many other conditions may be
prerequisites that are sensed by the circuit 22 and employed for
enabling transmission of the actuator word.
It will be readily appreciated that all of the components described
above as forming parts of the illustrated system, may be positioned
at any convenient location. Nevertheless, in a specific embodiment,
the system is adapted for remote actuation of a number of devices
from a single central command station. In such an arrangement, the
multistate devices, the state sensor and state change actuator will
all be located at one or several remote stations and a single
command station having a number of parallel communication channels
or having a single time shared communication channel, may be
provided for communication with all of the remote stations.
Although a parallel multichannel communication system is
functionally illustrated in FIG. 1, a time shared single
communication channel is employed in a specific fire control
embodiment to be described hereinafter.
Where the status words also identify a device classification, the
status selection circuit 20 will be arranged to select for
actuation either a group or one or more of the devices having a
particular classification (a rocket, for example) and having a
selected state (active and unfired) as will be described below. The
selection circuit may also be employed to select actuation of a
device according to a specified position or station location.
2. Aircraft Arrangement
Illustrated in FIG. 2, is an aircraft employing an embodiment of
the present invention to provide a pilot with information
concerning weapons carried by his craft and to allow him to control
the firing of these weapons. It will be readily appreciated that
the invention may be applied to systems for obtaining information
and control of weapons in other types of craft or at fixed
stations. The command or pilot information and control station 24
is preferably located in the cockpit and forms a part of the
pilot's control panel. One or more groups of weapons are carried at
different stations in the aircraft. Thus, in the example
illustrated in FIG. 2, where five remote weapon firing stations are
shown for purposes of exposition, there is a left outboard station
26, a right outboard station 28, a left inboard station 30, a right
inboard station 32, and a center station 34. Each of these stations
has one or a group of weapon-firing positions and one or a group of
weapons and firing mechanisms therefor at each such position. These
weapons may include rockets, guns, flares, bombs, missiles and
including triple and multiple injection rocket launchers. Each
weapon has a release mechanism such as a solenoid for a bomb, a
stepper switch for a multiple rocket launcher, or a firing squib
(resistance heater) for direct firing of rockets. Each such firing
mechanism will be actuated from its active or unfired state to a
weapon expended or inactive state upon command from the pilot.
Further, the actuating mechanism of each of the weapons is
continuously tested in the described embodiment. Status of the
weapon at each position is displayed to the pilot, although he need
not use this display since unexpended weapons of selected type are
automatically chosen. The number of remaining weapons of each
category or classification is also displayed. Weapon status is
stored in the command status memory so that upon a fire command
signal from a pilot, a fire pulse is sent automatically only to a
weapon that has not yet been fired.
3. Fire Control System
As illustrated in FIG. 3, the several remote operating stations 26
through 34, each includes a transceiver that operates the
individual remote station as more particularly described below in
connection with FIGS. 4 and 7. All of the remote stations are
connected in common to one end of a communication channel 37
through which information is transmitted between each of the remote
stations and the pilot information and control station 24. The
pilot information and control station includes a test word
generator 36 that separately generates groups of test words, the
groups being continuously repeated and each group containing a
number of test words each individual to a rspective one of the
weapon positions. For example, in a system having five stations and
six weapon positions at each station, there will be 30 test words
generated during each test cycle. Each of these test words includes
an address unique to an individual one of the weapon positions. The
test word generator may comprise any one of a number of well-known
devices for successively and repetitively generating the
predetermined words of predetermined format including either
read-write or read-only memories. In the exemplary embodiment
described herein, a read-only memory is employed. Exemplary word
formats are shown in Table I, set forth at the end of this
specification.
As shown in Table I, each test word may be made up of 19 bits. The
first three bits comprises a station identification code that
uniquely identifies a given one of the remote stations. A second
group of three bits uniquely identifies a particular weapon
position at the given station. A third group of three bits (random)
are not employed in a transmitted test word but occupy positions
that will bear weapon type information in a reformatted status word
assembled at the remote station. Another group of bits identifies a
function which for the test word, of course, is the test function
that is to be performed upon receipt and identification of the test
word station and position address. A final group of bits forms an
end-of-word code that enables identification of the end of the
given test word. If deemed necessary or desirable, transmission and
circuit errors may be recognized by use of selected parity bits.
Such parity bits are illustrated in the test word of Table I as
occupying bit position 4, 8 and 15. Bit position 12 is also a
parity bit in other words to be more particularly described
hereinafter.
Thus, the test words are sent out in repetitive groups through a
transmit gating circuit 38, down the common line 37 for reception
by the transceiver at all stations. Only one station will recognize
its own station address code for a given test word and will,
thereupon, enable its testing function to sense the state of the
addressed weapon position.
4. Transceiver
Illustrated in FIG. 4 is an exemplary transceiver which is
identical to the transceiver of each remote station, each such
remote station having its own transceiver. As illustrated in the
block diagram of FIG. 4, station and position address codes of the
transmitted test word are recognized in an identification circuit
40 that is provided in each transceiver. The identification circuit
40 is preset so as to enable it to recognize its own station code.
Accordingly, although every test word and every command word
transmitted from the command station is transmitted to every
transceiver, only one transceiver will recognize a given station
address to thereby generate a station enable signal on a line 42.
Each transceiver also includes a function decoder 44 which provides
an actuate output on line 46 or a test output on line 48. The
station/position I.D. circuit 40 also decodes the position address
and provides an enable signal on a line 50 that commands the
sensing of the state of a uniquely addressed weapon position by
enabling one of a group of position sensing gates 52. Thus, for a
given test word, one remote station is enabled, one weapon position
gate at such station is enabled, and state sensing (test) is
commanded by the function of the test word, and a signal
representing state of the sensed weapon is provided on line 54 of
the transceiver. The weapon status signal is fed to a status word
assembler 56 which provides on an output line 58 a status word
having a format of a type illustrated in Table I. The status word
includes, in addition to parity bits, station and position address,
a group of bits identifying the type of weapons at the particular
station, a group of bits representing the sensed weapon status and
again, a group of bits forming an end-of-word code.
Although each remote station may be provided with its own power
supply for empowering its transceiver or separate additional lines
may be employed to send electrical power to the transceiver, it is
convenient to provide each transceiver with an electrical energy
power storage circuit 60 that receives each data word or at least
selected data words sent down the communication channel 37 from the
command station. Circuit 60 stores energy contained in such data
words. The stored energy is transmitted as energizing power to all
of the electrical operating circuits at the transceiver.
The status word assembled at the transceiver is sent from
transceiver at line 58 along the single communication channel 37 in
the interval between the transmission of two successive test words
from the test word generator of the command station. The status
word is received at the command station and fed via a line 62 as an
input to a command status memory 64 (see FIG. 3). Command status
memory 64 may be any one of a number of different types of storage
devices having both read-out and write-in capability. The
read-write command status memory may employ magnetic core, random
access storage or recirculating shift register storage as described
below. The latter is chosen in the exemplary embodiment described
herein.
Thus, each time a test word is sent out through the transmit gating
38, it is followed by reception of a status word which is then
written into the command status memory. Accordingly, for each
complete cycle or group of test words, the command status memory is
completely updated.
According to a feature of the present invention, the words in the
command status memory are employed to enable the firing circuits of
the selected weapon and also to send a firing pulse down the line
to achieve the firing of the weapon. To this end, selection
circuitry 66 is provided to determine presence of certain fire
enable pre-requisites or conditions and, when these conditions
exist, extract from the command status memory an actuator or
command word having a format shown in Table I. It will be seen from
this table that the command words are nearly identical to status
words that are assembled in the transceivers and stored in the
command status memory. The bits in bit positions 13 and 14 are
identical in the two words but are employed for different
functions, being used to denote status of a particular device in
the status word and used to denote an actuate or fire function in
the command word. Thus, even these bits of the command and status
words are identical although they have different functions.
The command word extracted from the memory 64 under control of the
fire enable condition circuits 66 is fed through the transmit
gating 38 and thence down the communication channel 37 to all of
the transceiver stations. Referring again to FIG. 4, a station
identification circuit 40 at one of the remote stations will
recognize the station address code of the received command word and
its function decoder will provide a fire enable signal on its
output line 46. This fire enable signal will fully enable a
particular one of a group of position firing gates 70, all of which
are partially enabled by the station identification signal provided
from station I.D. 40.
Referring again to FIG. 3, recognition of selected conditions by
the circuit 66 not only commands extraction of a given status word
from memory 64, but also initiates operation of a fire pulse
generator 72 which, after a delay sufficient to allow complete
extraction of a command word from memory 64, sends an actuator
firing pulse through the transmit gating 38 and through the channel
37 for reception at all remote stations. As indicated in FIG. 4,
the firing pulse is fed to the position firing gates 70 of each
transceiver. The command word that preceded the firing pulse
included a unique station and position address so that one and only
one unique position at one and only one station (in this exemplary
embodiment) is enabled. The enabling of this unique gate in effect
arms a specifically addressed weapon so that when the firing pulse
is received, the weapon is fired. If desired, two positions may
have the same address so that two weapons may be fired
simultaneously. Alternatively, as will be described in detail
below, two or more different positions may be armed (enabled)
before sending a single firing pulse to all.
Timing of the time-multiplexed transmission is under control of a
timing circuit 76 that controls operation of several of the
circuits including the test word generator 36, transmit gating 38
and command status memory 64. The timing is such that transmission
of each test word is followed by reception of a status word and
storage of the received status word in the command memory. When a
firing command is given, the test cycle may be interrupted to
permit the firing and the testing may be resumed after firing has
been completed. Alternatively, each test cycle may be caused to
continue until its completion and any firing command may be
automatically delayed so as to occur only at the end of test cycle.
The latter arrangement is employed in the embodiment that is
described in detail below.
As each status word is received during a test cycle, it is not only
written into the command status memory, but it is also stored in a
holding memory 76 for display at the pilot's control station.
Holding memory 76 may comprise a group of flip flops, each
individual to a given weapon position and each, when in set
condition, for example, being connected to light a light
representing a particular weapon. In such a holding memory, of
course, there will be one flip flop and one light for each weapon
of the entire store. The holding memory includes suitable address
and position decoding to enable selective operation of a given
memory position.
Also of interest to the pilot is the quantity of weapons of a given
type that remain unfired. Accordingly, a remaining stores display
78 is connected for operation by words in the command status memory
64 to provide a count according to the weapon type code of each
status word of the number of such weapons having an active status.
These counts are conveniently displayed to the pilot according to
weapon type groups.
It may happen that a given weapon may malfunction and fail to fire
or a bomb may fail to be released even though an appropriate fire
command signal has been transmitted. Such a "hung" ordnance creates
a potentially dangerous condition. It is essential that a pilot
know at all times whether or not he is carrying live ordnance. In
order to advise the pilot of the occurence of a hung ordnance, each
command word extracted from the memory 64 during the course of one
complete mission, is fed to a fire commanded memory 80. The latter,
accordingly, stores every command word extracted from the command
status memory. The fire commanded memory will retain its
information content until it is manually reset, which may occur
when the varous weapon positions are again loaded for a subsequent
mission. The commanded words (words that have been used to fire a
weapon) in memory 80 are continuously compared with information
that represents status of the various weapons as indicated by the
continuous testing. Since the status words contained in the command
status memory, contain this information, being updated continuously
after each firing, the words in the fire commanded memory may be
compared with the words in the command status memory, comparing the
status bits of words having identical station and position
addresses. Alternatively, as shown in FIG. 3, the words in the fire
commanded memory are continuously compared in a comparator 82 with
information derived from holding memory 76. The latter also
contains information identifying status and address of individual
weapons. Accordingly, in the event that the comparison of commanded
weapon positions with tested status of such weapon position,
indicates that a particular fire command has not been executed,
comparator 82 will provide an output signal warning the pilot of
the existence of a hung ordnance and will also identify the
position of such hung ordnance. With such warning, a pilot may
select the identified position of the hung ordnance and, by a
priority override firing system to be more particularly described
below, send a second or additional fire command to the
malfunctioning position.
From the described functions of the command station shown in FIG.
3, including details to be described hereinafter, it will be
readily appreciated that this command station may largely comprise
a standard small scale general purpose data processing digital
computer. In particular, with the widespread advent of computers
made of large-scale integrated circuits, and particularly the
LSI-MOS circuits, standard computers capable of being programmed to
perform the required functions of the described command station are
available at quite low cost. Such computers include memories
capable of storing several thousand bits of information, which is
more than adequate for the described exemplary embodiment of this
invention, together with the required data processing and
appropriate input, output circuitry. Alternatively, a special
purpose computer may be employed to carry out the functions of the
command station of FIG. 3. Such a special purpose computer is shown
for purposes of exposition in the detailed drawing collectively
formed by FIGS. 5a through 5e inclusive.
5. Test-Mode Details
FIGS. 5a through 5e collectively illustrate details of the pilot
command station shown in FIG. 3. These five sheets of drawing form
a single diagram when arranged consecutively from left to right
with FIG. 5a on the left. All test words are stored in a read-only
memory (FIG. 5d), the test word generator memory 36, and read out
one after the other upon being sequentially addressed by the output
of a seven-stage address counter 90, of which the count is
augmented by a true data mode control signal. The address counter
sequentially addresses successive words of the test word generator
memory and is reset from an AND gate 92 that is enabled by the
pickle signal P (from the pilot's fire control switch) together
with a signal from an end-of-test cycle decoder 94. As the address
counter 90 steps to a given address of the test word generator
memory, a particular test word is read out in parallel to a line
word register 96. The test word is clocked out of the line-word
register by the output of an AND gate 97 that is enabled by the
data-mode control signal (when true) together with the system
clock.
The true data-mode control signal is provided from a data-mode
control flip-flop 98 (FIG. 5e) (when set). The test word is clocked
out to a first AND gate 100 of a transmit control gate M8. AND gate
100 is enabled by the output of an AND gate 102 receiving the
signal P (absence of P) together with a signal from the end-of-test
cycle decoder 94. AND gate 100 of transmit control gate M8 will
send the test word through an OR gate 104, through a line driver
106, and then down the line 37 to the transceiver where the word is
recognized, weapon status identified, and a status word reformatted
and transmitted back to the pilot control system for reception in a
line receiver register 108 (FIG. 5e).
Although various voltage levels may be employed for logic and fire
pulse, it is found convenient to use logic signal levels of 15
volts in both command and remote stations. Because a fire pulse of
28 volts is normally used in a weapon firing system to which the
present invention may be retrofitted, the 15 volt logic (data word)
is employed to gate 28 volt pulses through the line driver so that
all data words sent from the command station, and the fire pulse
itself, are formed of 28 volt pulses. The data words (but not the
fire pulse) are conveniently attenuated to 15 volt pulses at the
transceiver. The status words are sent back as 15 volt pulses.
Upon reception of the status word via an input line 109 of the line
receiver register 108, an end-of-word decoder 110 sends a signal
via delay 99 to set the data-mode control flip-flop 98. This
flip-flop resets itself after a delay that is provided by a delay
circuit 97 that is slightly greater than the length of one test
word (about 19 bits). Alternatively, the data-mode control signal,
which is to be true for one word time, may be a one shot
(monostable multivibrator) that is triggered by the output of
end-of-word decoder 110 and returns to its stable state at the end
of its timing interval. Now the data-mode control signal is high
and a second address advance signal is sent to the counter 90 via
line 91 to achieve readout of the second test word.
This testing cycle continues throughout a full readout of all of
the words of the test word generator memory. That is, each test
word is readout, sent down the line 37 to the appropriate
transceiver where it is reformatted and sent back as a status word
to be received and retained temporarily in the line receiver
register. The status word in the line receiver register 108 is read
out in parallel to a group of AND gates including gates M15-M20
that have a first enabling input from the end-of-word decoder 110.
Outputs of these gates are connected to set flip-flops including
those designated M21-M26 that form the holding memory 76.
Each of the flip-flops of the holding memory when set operates a
corresponding indicating light, such as lights 105, 107, that are
mounted in a pilot information display. Thus, if one of the
flip-flops is set to light its corresponding light, a display is
provided to the pilot indicating that the weapon at the position
corresponding to the activated light is in active state. In
addition to the first enabling inputs provided from the end-of-word
decoder 110, station and position address information is fed as
second and third enabling inputs to the decoding AND gates M15-M20.
For example, the six gates shown in FIG. 5e represent six weapon
positions at a single station. Corresponding gates, flip-flops and
lights for weapon positions at other stations are not shown. Thus,
a station enabling input corresponding to a given station enables
all of the gates M15-M20 via a line 111. Additional enabling
inputs, one for each of the gates M15-M20, are provided each
individual to a bit designating a specific position as contained in
the status word temporarily stored in line receiver register 108. A
fourth enabling input to the decoding gates M15-M20 is the actual
status information from the status bit position of the line
receiver register, and is fed to all of the decoding gates via a
line 113. Each of the holding memory flip-flops is reset via an
inverter connected between its reset input and the output of its
own gate. Accordingly, each flip-flop is reset after the brief
interval during which a status word corresponding to the particular
position is held in the line receiver register. However, the light
driving circuitry and the lights have sufficient inertia (acting as
an integrator) and the test cycle is repeated so rapidly (each 30
milliseconds for example) that each light corresponding to an
active weapon position will remain continuously lit. Only when a
weapon has been fired, so that a status word no longer provides
exitation for a given light, will the light of the holding memory
display be extinguished.
After a suitable delay sufficient to allow the holding memory
flip-flops to settle, the status word is serially read from the
line receiver register into the recirculating command memory via a
line 115. At the same time, the second test word is read into the
line word register from the read-only memory 36, and clocked out to
the appropriate transceiver.
When the last address of the test-word generator is activated, the
end-of-test cycle decoder 94 produces an end-of-test cycle signal.
The end-of-test cycle decoder signal is combined with the pickle
signal in AND gate 92 to reset the address counter 90. The
end-of-test cycle signal also enables an AND 103 in the transmit
gate M8 so that a fire command signal may be transmitted (if
commanded) only at the end of a full test cycle.
6. Reception of Status Word
As a status word comes down the line 37 from a transceiver, it is
simultaneously fed via line 109 to the input of the
serial-in/serial-out/parallel-out line receiver register 108 and
also fed to a self-clocking generator comprising an OR gate 112 and
a toggle flip-flop 114. The output of the toggle flip-flop is fed
to an AND gate 116 which is enabled by the absence of an output
from end-of-word decoder in 110. The output of gate 116 is fed
through an OR gate 118 as a self-clocking input to the line
receiver register.
When the end of the status word is recognized in the decoder 110,
the self-clocking AND gate 116 is disabled and, after a delay, the
data-mode control flip-flop 98 is once again set to thereby advance
the address counter of the test-word generator memory. The
data-mode control flip-flop 98 now also enables a system clock AND
gate 120 and also blocks the recirculating path of the command
status memory and enables the data entry path of the command status
memory, as will be described below.
The true data-mode control signal from flip-flop 98 signal enables
clock gate 120, which accordingly clocks out the status word via
line 115 to the data entry gating 122 of the recirculating command
status memory (FIG. 5c). Data entry into this memory is enabled by
a true data-mode control signal fed to an AND gate 123, whereas an
AND gate 124 in the recirculating path of this memory is
concomitantly disabled by such a true data-mode control signal.
Nevertheless, the system clock continues to cause recirculation of
the words in the memory so that the recirculating data words fed
into AND gate 124 are simple erased and replaced by words coming
from the line receiver register through now enabled gate 123 and
the OR gate 125 of the data entry gating.
Thus, during each test cycle, all of the words in the command
status recirculating memory are replaced by updated status words.
Therefore, a full complement of status words, one word for each
weapon position, is contained in the command status memory.
7. Command Status Memory
The command status memory may be any one of a number of different
types of read-write memories, such as for example, a random access
core memory or a recirculating shift register type memory. In the
latter, a large part of the storage may be placed on a magnetic
disc or magnetic tape or the like with suitable read-out and
write-in devices interconnected by conventional flip-flop shift
registers. In the illustrated embodiment, the recirculating memory
is a single closed loop of flip-flop shift registers including
chips M28-M34, although provision for both serial and parallel
read-out from certain portions of this memory is included as well
be described hereinafter.
Information flow through the memory is under control of a system
clock pulse train that is generated by a clock oscillator 126 and
clock generator 128, interconnected by a line 127, at a frequency
that will provide a single bit time of, for example, 1 microsecond.
Obviously, clock rates and timing intervals may be varied as deemed
necessary or desirable. Speeds of available circuits are more than
adequate to handle all necessary information flow rates.
The function of the recirculating memory is to store status words
identifying each weapon type, station and position address, and the
status of the weapon at such an address, that is, whether the
weapon is active or expended, for example. An exemplary status word
format is shown in Table I. The storage of these status words is
arranged so that when appropriate fire conditions (prerequisites)
exist, as selected by the pilot, or as occurring in the system, a
command word may be released from the recirculating memory and sent
down the line to the several transceivers. That one of the
transceivers which recognizes its own identification (station
address) contained in the fire command word, arms a selected weapon
and conditions itself for receipt of the fire pulse that
automatically follows each command word that is sent down the
line.
A command word is released from the recirculating memory along a
command output line 128, from a NAND gate 130. Such command word is
fed through the NAND gate 130 via a line 129 from the output of one
section M34 of the recirculating shift register memory. NAND gate
130 is enabled by the high output (when in set condition) of a fire
enable flip-flop 134. The latter is set by the output of a NAND
gate 136, having a first enabling input via a line 137 from a NOR
gate 138. The latter receives a first input on line 140 which input
identifies a type of weapon selected by switch 141. The weapon type
input on line 140 may be overridden by a priority override position
command signal provided at the output of an AND gate 142 via
position and station selector switches 144 and 146, respectively.
When station switch 146 is in the "norm" position, one input to
gate 142 is disabled and firing is effected by weapon type. The
priority override of switches 144, 146 allows selection of a given
position. The contacts of switches 141, 144, 146 and connected to
the outputs of the illustrated decoders that have inputs from
status word code bits for weapon type, position and station,
respectively.
The pilot may desire to fire a particular weapon at a known
position under various circumstances. For example, he may know such
position has a hung ordnance that has been commanded to fire but
has not actually fired. Alternatively, it may be known that a
special type of weapon, such as a smoke flare for example, is
located at a particular position. In any event, a first fire
condition signal is provided either by weapon type or priority
override position to enable gate 136.
Additional command prerequisites or fire conditions, namely,
conditions that must exist before a fire command word is released
down the line, are provided by means of a NAND gate 148. When and
only when all of the inputs to NAND gate 148 are true, a command
enable input is fed via a line 147 to NAND gate 136 to thereby
provide an output to set the fire enable flip-flop 134. This will
release a command word to the command word output line 128. To
ensure that any commanded firing pulse has been terminated before a
second fire command word is released, gate 136 is temporarily
disabled during such firing pulse by a third input on line 145.
A first condition input to gate 148 is a word position input on a
line 149 which is derived from an end-of-word decoder 150 which
produces an output signal whenever an end-of-word code of the
circulating status words is recognized as existing in predetermined
positions of the recirculating memory. Knowing the position of the
status word in the recirculating memory, the status code bit or
bits (only 1 bit is required if there are no more than two possible
states) are sensed to provide on a line 152 a second input, the
status input, to the fire condition gate 148. The status input is
true only when the status code indicates that the store in the
particular address of the given status word is active.
A third input to fire condition gate 148 is provided on line 153 as
a quantity per salvo signal that is true when and only when the
quantity of stores fired in any one salvo is less than that set
into the salvo counter.
A predetermined quantity of units to be fired in a given salvo is
selected by the pilot by operation of manual switches connected to
output terminals derived from units and tens salvo quantity
counters M47, M48 (FIG. 5c). Each fire enable signal from NAND gate
136 is sent as a counting input to the units counter M47, and when
both units and tens counter reach the preselected count, a NOR gate
161 is enabled to set a quantity per salvo flip-flop 163. This
flip-flop is normally reset to provide the quantity per salvo
enabling input to gate 148 via line 153. The quantity per salvo
flip-flop 163 is reset by the signal P (absence of pickle) that is
provided from a pilots pickle flip-flop 160 (FIG. 5a). Thus, the
salvo flip-flop 163 is reset before a fire command or pickel signal
is executed. When the pickle signal occurs it remains reset until
the quantity counters M47, M48 indicate that the preselected
numbers of weapons have been fired during the occurrence of the
given pickle signal. With flip-flop 163 set, the enabling input on
line 153 is removed and firing ceases.
A fourth input into the fire condition gate 148 is provided on a
line 154 as an interval signal that is true only when a
predetermined or preset interval (preset by the pilot) has elapsed
since the last fire command word was released.
Where parity bits are included in the several words, a parity
enable signal on a line 155 from a parity decoder 156 is a fifth
input to the fire condition AND gate 148 and is true when the
output of parity decoder 156 determines that predetermined parity
of the particular status word exists.
Still another input to the fire condition gate 148, is provided on
line 158 as the pickle signal. This is the signal derived from the
true output of fire control flip-flop 160 when the latter is in set
condition. The pilot's pickle (fire control) switch 159 is spring
actuated so as to normally rest in a position to provide a true
input to the reset side of flip-flop 160 to thereby ensure the
absence of a pickle signal. When the pilot depresses the pickle
switch, a true input is provided to set the flip-flop and even
through the pickle switch should be subject to severe bounce, the
flip-flop is and remains set, acting as a self-latching switch.
When all of the conditions or inputs to fire condition gate 148 are
true, whereby all inputs to NAND gate 136 are true, fire enable
flip-flop 134 is set to enable the read-out gate 130, which
whereupon releases a status word to the command output line 128.
The word positioning of the end-of-word decoder 150 is so chosen
that when the enable flip-flop 134 is set, the next bit of status
word that is fed into output gate 130 is the first bit of the
word.
With the fire enable flip-flop set, an enable signal is fed to a
bit counter 162 that counts system-clock pulses. When counter 162
has counted a number equal to the number of bits in a word (19 in
the illustrated embodiment), and end-of-command word signal is fed
via an OR gate 164 to reset the fire enable flip-flop 134. If two
or more weapons are to be fired (substantially) simultaneously bit
counter 162 is (manually) set to count the bits in the desired
number of command words so that a plurality of weapons will be
armed and ready to receive the fire pulse that is sent to the
transceivers after transmission of the chosen command word or
words. The end-of-command word signal provided at the output of bit
counter 162 is also sent via an OR gate 166 to provide a reset
signal to reset an interval counter comprising serially connected
counters 167, 168 and 169.
The interval counter provides an enabling input on line 154 for
gate 148 either when both tens and hundreds counters 168 and 169
are set to zero (via manually settable switches 171, 173) or when a
particular finite interval as determined by preselected position of
switches 171, 173 has elapsed. The interval counter counts pulses
received from clock oscillator 126 via a divider 175 and provides
an output from the respective switches 171, 173 to an AND gate 177
that is fed together with the output of an AND gate 179 to an OR
gate 181 to produce the elapsed interval signal on line 154.
8. Fire Pulse
As each fire command word is released down the line, it is
recognized by the addressed transceiver station which thereupon
arms that one of the weapon positions at such a station that is
addressed by the particular command word. Having armed the weapon
position, a fire pulse is thereupon sent down the line to fire the
armed weapon. The fire pulse generating circuitry is triggered from
the command enable signal that is provided at the output of fire
conditioning gate 148. The output of the latter on line 147 is fed
to trigger a one shot or mono-stable multivibrator 170 that
provides a delay, such as 100 microseconds, for example. This delay
is long enough to ensure that several command words may be sent
out, head to tail, along the command output line 128, when the bit
counters 162 is set to count several words. At the end of the delay
of the fire one shot 170, a fire pulse one shot or mono-stable
multivibrator 172 is triggered, having a delay period of the
duration of the fire pulse itself. In an exemplary embodiment, this
period of the second or fire pulse one shot is about 15
milliseconds. When the second one shot is triggered, the fire pulse
183 is initiated and remains high until termination of the delay
period of the second one shot. The fire pulse is fed through an AND
gate 174 that is enabled by a true pickle signal. The output of
this AND gate is fed via a line 185 as a third input to the OR gate
104 of the transmit control gating and thence through the line
driver 106 down the line to the several transceivers.
In order to be sure that another fire command word is not sent down
the line until the fire pulse is terminated, the output of the
second one shot is inverted and fed via line 145 as a third input
to AND gate 136 so that the latter is disabled whenever the fire
pulse is high.
After the fire pulse has been sent down the line, another fire
command word will follow, if the pilot still has the pickle switch
depressed and a pickle signal still exists. If the pickle signal no
longer exists, the system immediately returns to its test mode. The
transmit control gating, in the absence of the pickle signal, now
enables gate 100 (FIG. 5d) and disables gate 103 to allow the first
word from the test word generator memory to be passed down the line
and the next full test cycle commences. The first test word of this
next test cycle was read from the test word generator memory into
the line word register 96 during the preceding test cycle, while
the last status word of such preceeding test cycle was being read
from the line receiver register into the recirculating memory.
Thus, in the absence of the pickle signal, the test cycle starts
again and when the first test word is returned as the first status
word, the test word generator memory is advanced and the next test
cycle continues as previously described.
9. Remaining Stores Display
Although many codes of mechanization of the display of active
stores remaining in each of the various weapons types are possible
from the formation contained in the command station, a preferred
mechanization is illustrated in that portion of the diagram
contained in FIGS. 5a and 5b. A plurality of coincidence gates 300,
302, 304, 306, each individual to a selected weapon type such as
rocket, bomb, flare and ordnance, for example, are each fed with a
first enabling input from the respectve output terminals of the
weapon type decoder switch 141. Thus, each time a status word
representing a rocket passes through the recirculating register,
gate 300 is enabled, for example. Each time a status word
representing a bomb passes through the recirculating register, gate
302 is enabled. Similarly, gates 304 and 306 are enabled by status
words for flare and ordnance devices, respectively.
A second input to each of the coincidence gates 300, 302, 304, 306
is derived from the fire or status bit signal on line 152 that is
extracted from the status word at recirculating register section
M32. Accordingly, if a status word includes a status bit indicating
active or unfired state, and also identifies a particular weapon
type such as rocket, for example, gate 300 provides an output which
feeds a pulse to a units counter 308 having a carry input to a tens
counter 310. Units and tens counters 308, 310, respectively,
operate display lights in the remaining rockets display panel.
Accordingly, there is a display provided of the total number of
unexpected rockets. Similarly, gates 302, 304 and 306 provide
outputs that trigger corresponding counters for numerical displays
of bombs, flares and ordnance, respectively.
Counters 308, 310 and corresponding counters for bombs, flares and
ordnance are reset by a signal on a line 312 from the output of a
counter 314 (FIG. 5b). Counter 314 receives as its counting input
an output from the end-of-word decoder 150, previously described,
so that the counter 314 augments its count by a single unit for
each full status word in the recirculating register. Counter 314
provides an output on line 312 when it has counted a number equal
to the total number of status words in the recirculating register.
Accordingly, when all of the recirculating words have been
monitored by the coincidence gates 300, 302, 304 and 306, the
remaining stores display will now display a correct number
representing the number of stores remaining of the respective
weapon types. When the counters 308, 310 and their counterparts for
each of the other weapon types, are reset by the signal on line
312, they again begin to count active weapons of the several
types.
Even though the remaining stores display counters are reset after
each complete recirculating cycle, the persistence or delay
inherent in the display devices operates as a short-term memory
sufficient to provide the pilot with the maximum counted
information. If such "memory" is not considered to be adequate, the
connection between the units and tens counter 308 and 310 and the
display devices may be temporarily disabled upon occurrence of the
reset signal so that the number contained in such display will not
immediately be changed by resetting or by several succeeding
counts. This may be achieved by a suitable delay and gating not
shown in the drawings.
10. Transceiver Details
FIG. 6 illustrates details of an exemplary transceiver unit of the
type shown in FIG. 4. As previously described, the transceiver unit
receives a digital data (test or command) word from the
transmission line, conditions it and executes the data function
contained in the word. In addition, the transceiver will assemble a
data word (the status word) to be transmitted and returned to the
pilot information command station for processing.
Serial data words comprising a series of asynchronous bits are sent
down the transmission line 37 from the pilot information command
station. The data words are transmitted through an attenuating
resistor R, via a line 187, to an input register 188, 190. The data
words are also fed through resistor R, and thence, to a clock
regenerator 180, comprising a pair of differential amplifiers 181,
182, each of which has one of its differential inputs connected to
a plus or minus source of potential, as indicated, and each of
which has the other of its inputs connected to receive the serial
bits of the data word. The amplifier outputs are fed through a NOR
gate 184 and, thence, through a normally enabled NAND gate 186 to
provide a clock signal for the transceiver. The clock pulses from
the clock regenerator are employed to clock the input shift
register 188, 190 which has serial inputs and both serial and
parallel outputs. This transceiver input register may be
conveniently made up of several sections of the previously
described shift register chips employed for memories and registers
of the pilot information command station.
An end-of-word decoder 192 senses occurance of the last four
end-of-word code bits of the command or test words and generates a
signal which is sent via a line 193 to disable the normally enabled
NAND gate 186 that feeds the regenerator clock pulses to the
transceiver. Thus, the data word has been clocked into the input
register and remains there until the transceiver receives another
command or test word.
A manually controllable station number rotary switch 194 has its
movable arm 195 set to a particular one of its contacts that
identifies the station number associated with the individual
transceiver. The several station number contacts are connected with
a station decoder 196 having inputs from the three bits that form
the station code of the word retained in the input register.
Accordingly, when the station code of the command or test word
matches the preset identification of station established by the
switch position, a station ID signal appears on a line 197 as a
first enabling input to each of three coincidence NAND gates 198,
199 and 200. The exemplary transceiver shown in FIG. 6 is adapted
for operation of three different weapon positions. It will be
readily appreciated that any given transceiver may be readily
adapted to operate more or less than three different weapon
positions by suitable changes in the number of gating and related
circuits.
A position decoder 202 senses the three position bits of the
command or test word and, depending upon which position is
identified by the code, provides a position enabling signal on that
one of its output lines that is connected to enable that one of the
coincidence gates 198, 199 and 200 that is arranged to arm the
chosen position.
A function decoder 204 is connected to sense the bits in the
function code of the command or test word, and provide as its
output on a line 205 a signal having one state or the other to
evidence either fire or test respectively. If the output of the
decoder 204 evidences a fire function (e.g., a command word has
been recognized), a first input of a fire coincidence gate 206 is
enabled. Where parity decoding is employed, gate 206 will operate
only in the presence of a true parity signal from a parity decoder
208 having inputs connected to sense the several parity bits of the
test or command word. The output of the fire gate 206 is fed as a
third enabling input to all of the position coincidence gates 198,
199 and 200. Accordingly, upon recognition of (a) the given station
code, (b) the fire function and, (c) true parity, all of the gates
198, 199 and 200 are disabled ("armed") whereby that one selected
by an output of position decoder 202 will pass a signal to the base
of an associated one or driving transistors 210, 211 and 212.
Firing transistors 214, 215 and 216 are provided, individual to
each of the firing squibs or firing resistors F.sub.1, F.sub.2 and
F.sub.3 of the respective weapons at the several positions. The
firing squibs F.sub.1, F.sub.2 and F.sub.3 are shown as resistances
only for purposes of exposition. These are the actuated elements of
the remote stations and may be relays, solenoids or the like, or
other firing or weapon release mechanisms as appropriate for the
weapon employed. Each firing transistor 214, 215 and 216 is
connected in series with a firing resistor F.sub.1, F.sub.2 and
F.sub.3 and with the transmission line 37. When a fire pulse 183 is
received, having a level of 28 volts, for example (unattenuated by
the resistor R), it will be passed via fire pulse line 209 through
one and only one of the firing transistors 214, 215, 216 depending
upon which has been energized by an arming signal fed to its base
by an associated one of the driving transistors 210, 211, 212.
The several circuits need not be reset since each receives and
responds to succeeding incoming signals. Alternatively, reset of
the transceiver circuits at each data word reception may be
provided by a word beginning code that is recognized by a decoder
(not shown) in the transceiver to provide a brief transceiver
resetting signal at the beginning of each word sent down the
line.
Accordingly, the selected weapon has fired and the transceiver
input register 188, 190 awaits the next command or test word. If
the next word is a second command word, the above-described
procedure is repeated for the particular weapon position addressed
by such next word. This cycle may continue until all weapons at the
given station have been fired or until a selected number of weapons
at the station or at other stations have been fired. Now, if the
next data word is a test word, the above-described operations
relative to response to a command word will occur with the
exception of the function decoder output and firing circuit
operations. For a test word, the function decoder output will not
enable the fire enable gate 206, wherefore none of the firing
transistors 214, 215, 216 will be turned on. Further, no fire pulse
will be sent down the line, although no firing would occur even if
such pulse should occur inadvertently. The system will not fire a
weapon unless a given position is first armed by a command
word.
The output of the function decoder in the case of a test word will
be transmitted through a coincidence gate 220 which receives as its
second input a signal representing true parity. Accordingly, if
parity exists and the data word function code is test, a test
enable signal appears on a line 221 to provide an enabling input to
a test coincidence gate 222. The second input to gate 222 is
provided from a NOR gate 224 that receives the outputs of three
coincidence gates 226, 228, 230. Each of the latter has a first
enabling input on line 197 from the station enable signal provided
from the station switch arm 195. A second enabling input is
provided to that one of the gates 226, 228, 230 which is associated
with the position identified in the position code of the test word.
This second enabling input is from the outputs of position decoder
202. The third input to each of gates 226, 228, 230 is provided as
a continuity circuit to ground through a respective one of the
firing squibs or resistors F.sub.1, F.sub.2, F.sub.3. This third
input provides the weapon status sensing and generates for the
system the indication of the state of the weapon. If the weapon has
not been fired and is an active state, a continuity signal is
provided to the respective gate. If the weapon has been fired, no
such signal is provided. Accordingly, the output of the coincidence
gate 222 provides a weapon status signal for the weapon in the
position identified by the position code of the test word, and
which position is at the station identified by the test word
station code.
The output of function decoder 204, when a test word is contained
in the input register 188, 190 is also fed, after a delay in a
circuit 231, to enable a local clock oscillator 232 comprising a
NOR gate 234 feeding a NOR gate 236 and having a
resistance-capacitance feedback network as indicated. When enabled,
the local clock oscillator 236 provides a clock input to a
transceiver output register 238, 240 which is of the parallel in
serial out type. The clock input causes a status word in this
register to be clocked out bit by bit and transmitted from the
transceiver to the command station.
The status word clocked out of register 238, 240 is assembled
during the state sensing carried out in response to this test word.
The output register is the data assembler of the transceiver. It is
employed to assemble and format the transceiver status word.
Station and position coding are transferred from station and
position coding of the input register 188, 190 directly to
appropriate positions of the output register when the parallel
inputs to this register are enabled by the clock enable signal on
line 239 (without delay).
A weapon type encoder 242 has a weapon type code indicative of a
particular type of weapon, such as bomb, rocket or the like, set
into it by means of a manual switch 244 so that a particular
station and transceiver can be coded to identify the weapon type
that has been loaded at such station. The weapon type encoder,
having connection to the status word bit positions that represent
weapon type provides this coding for the status word. Similarly, a
parity code generator 246 and and end-of-word code generator 248
provide inputs to the output register to insert the corresponding
parity and end-of-word code information therein. The output of
coincidence gate 222 is employed to establish the bit
representating status. Only a single bit is required where only two
states are available.
As previously noted, the output of parity decoder 208 is fed to the
coincidence gate 220 together with the test function output of
decoder 204. The parity decoder output is also fed into the output
register 238, 240 to indicate existence of a parity error. If the
parity bit indicates that a test word received by the transceiver
is in error, the parity decoder 156 (FIG. 5b) connected with the
recirculating memory will prevent enabling of the fire condition
gate 148. Further, if deemed necessary or desirable, additional
circuitry (not shown) may be provided to repeat transmission of an
erroneous test word. However, the continuing and repetitive test
cycles of the test word generator, requiring only about 30
milliseconds or less per full cycle, will repeat this erroneous
word in the next test cycle.
11. Transceiver Power Supply
The data word pulses, comprising a train of positive going and
negative going 15 volt pulses (having been attenuated by resistor
R) have their positive going portions fed through a diode 250 to
charge a storage capacitor 252 that has its maximum charge value
limited to the selected transceiver supply voltage level by a zener
diode 254. The transceiver supply, at the function of diode 250 and
capacitor 252, is fed to provide electrical power to all of the
transceiver circuits. The data bits have sufficient magnitude and
energy content to operate the describing processing circuits and
also to charge capacitor 252 and maintain such charge. If deemed
necessary or desirable, the discharge time (the RC time constant)
of the energy storage circuit is made greater than the length of a
single test cycle so that if words of a first test cycle are
unacceptably attenuated by a completely discharged storage
capacitor, the test cycle is repeated before the capacitor is again
discharged.
TABLE I
Status Word Command Word Test Word 1 2 Station Station Station 3 4
Parity Parity Parity 5 6 Position Position Position 7 8 Parity
Parity Parity 9 10 Weapon Type Weapon Type Random 11 12 Parity
Parity Parity 13 Function Function 14 Status (Fire) (Test) 15
Parity Parity Parity 16 17 End of End of End of 18 Word Word Word
19
The foregoing detailed description is to be clearly understood as
given by way of illustration and example only, the spirit and scope
of this invention being limited solely by the appended claims.
* * * * *