CONTROL SYSTEMS FOR MOVING BODIES

SYSTEME DE CONTROLE POUR DES CORPS EN MOUVEMENT

English Abstract

A missile has a rotatable portion and control means for
rotating said rotatable portion to bring it to any one of a
plurality of preselected positions in relation to a datum and
for exerting a thrust thereon having a lateral component with
respect to the axis of rotation to produce a steering effect.
The control means includes a variable-incidence control surface
mounted on the rotatable portion for rotation about a rotary
axis transverse to the rotary axis of the rotatable portion.
Actuator means responsive to control signals turns the control
surface about its rotary axis to a position to produce a
component thrust causing rotation of the rotatable portion.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A missile or other moving body comprising a rotatable
portion arranged for rotation relative to another portion of the
missile or body and control means for rotating said rotatable
portion to bring it to any one of a plurality of preselected
positions in relation to a datum and for exerting a thrust thereon
having a lateral component with respect to the axis of rotation of
said rotatable portion to produce a steering effect on the missile
or body, said control means including a variable-incidence control
surface mounted on the rotatable portion for rotation about a
rotary axis transverse to the rotary axis of the rotatable
portion, and actuator means responsive to control signals for
turning said control surface about its rotary axis to a position
to produce a component thrust causing rotation of said rotatable
portion.



2. A missile or other moving body comprising a rotatable
portion arranged for rotation relative to another portion of the
missile or body, first control means for rotating said rotatable
portion to bring it to any one of a plurality of preselected
positions in relation to a datum and second control means on said
rotatable portion for exerting a thrust thereon having a lateral
component with respect to the axis of rotation of said rotatable
portion to produce a steering effect on the missile or body, said
first control means including a variable incidence control surface





mounted on the rotatable portion for rotation about a rotary axis
transverse to the rotary axis of the rotatable portion and
actuator means responsive to control signals applied thereto for
turning said control surface about its rotary axis between two
positions in the first of which the aerodynamic forces acting on
the control surface produce a component thrust causing rotation of
said rotatable portion in one sense and in the second of which the
aerodynamic forces acting on the control surface produce a compo-
nent thrust causing rotation of said rotatable portion in the
opposite sense.



3. A missile according to claim 2, wherein said second
control means comprises an elevator control surface mounted on the
rotatable portion for rotation about an axis transverse to the
rotary axis of the rotatable portion and elevator actuator means
responsive to control signals for turning the elevator control
surface about its rotary axis to a deflected position in which it
exerts a thrust on the rotatable portion having a lateral compo-
nent with respect to the axis of rotation of said rotatable
portion.



4. A missile according to claim 2, wherein the control
means comprises a gyroscope mounted in the rotatable portion and
arranged to generate a signal representative of the angular
position of the rotatable portion with respect to a datum, a
receiver mounted in the missile for receiving signals from a





control station representative of a required position for the
rotatable portion with respect to said datum, a comparator for
generating a control signal representative of a difference between
the signal generated by the gyroscope and the signal received from
the control station, and means for applying said control signal to
operate said actuator means.



5. A missile according to claim 4, wherein the actuator
means comprises the armature of a solenoid arranged to be ener-
gised in one sense in response to a control signal above a prede-
termined level to cause the control surface to move to the said
first position and to be energised in the opposite sense in
response to a control signal below said predetermined level to
cause the control surface to move to the said second position.



6. A missile according to claim 5, comprising a switch
device for reversing the energising current to the solenoid in
response to a change in the control signal.



7. A missile according to claim 3, wherein said elevator
actuator means is responsive to control signals for turning the
elevator control surface about its rotary axis between two deflec-
ted positions in the first of which the aerodynamic forces acting
thereon produce a lateral component thrust on said rotatable
portion away from the axis of rotation of said rotatable portion
in one sense and in the second of which the aerodynamic forces





acting on the elevator control surface produce a lateral component
thrust on said rotatable portion away from the axis of rotation in
the opposite sense, and wherein said control means further in-
cludes a receiver for receiving mark-space signals transmitted
from a control station and means to apply said mark-space signals
to said actuator to cause said actuator in response to a mark
signal to move the elevator control surface to said first position
and in response to a space signal to move said elevator control
surface to said second position, whereby variation in the mark-
space ratio of the mark-space signals produces a difference in the
periods for which the elevator control surface remains in the
first and second positions, thereby producing a resultant steering
force on the missile.



8. A missile according to claim 7, wherein the actuator
means comprises the armature of a solenoid arranged to be ener-
gised in one sense in response to a received marks signal to cause
the further control surface to move to the said first position and
to be energised in the opposite sense by a space signal to cause
the further control surface to move to the said second position.



9. A missile according to claim 8, comprising a switch
device for reversing the energising current to the solenoid in
response to a change in the control signal.


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10. A missile or other moving body comprising a rotatable
portion arranged for rotation relative to another portion of the
missile or body and control means for rotating said rotatable
portion to bring it to any one of a plurality of preselected
positions in relation to a datum, and for exerting a thrust there-
on having a lateral component with respect to the axis of rotation
of said rotatable portion to produce a steering effect on the
missile or body, said control means including variable incidence
control surfaces each of which is mounted on the rotatable portion
for rotation about an axis transverse to the rotary axis of the
rotatable portion and actuator means responsive to control signals
for turning the control surfaces about their rotary axes to first
dispositions in which they act as ailerons causing rotation of the
rotatable portion and to second dispositions in which they act as
elevators to effect steering of the missile.



11. A missile or other moving body comprising a rotatable
portion arranged for rotation relative to another portion of the
missile or body and control means for rotating said rotatable
portion to bring it to any one of a plurality of preselected
positions in relation to a datum and for exerting a thrust thereon
having a lateral component with respect to the axis of rotation of
said rotatable portion to produce a steering effect on the missile
or body, said control means including aileron control surfaces
each of which is mounted on the rotatable portion for rotation
about an axis transverse to the rotary axis of the rotatable


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portion, aileron actuator means responsive to control signals for
turning said aileron control surfaces about their rotary axes to
deflected positions in which they produce a component thrust caus-
ing rotation of said rotatable portion, elevator control surfaces
each of which is mounted on the rotatable portion for rotation
about an axis transverse to the rotary axis of the rotatable
portion, and elevator actuator means responsive to control signals
for turning the elevator control surfaces about their rotary axes
to deflected positions in which they exert a lateral component
thrust on the rotatable portion in a direction away from the axis
of rotation thereof.



12. A missile according to claim 11, wherein said aileron
control surfaces are rotatable about their rotary axes between two
dispositions, in the first of which the aerodynamic forces acting
on the aileron control surfaces produce a component thrust causing
rotation of said rotatable portion in one sense and in the second
of which the aerodynamic forces acting on the aileron control
surfaces produce a component thrust causing rotation of said rota-
table portion in the opposite sense, and wherein said aileron
actuator means is responsive to control signals for turning said
aileron control surfaces to the one or the other of the said first
and second dispositions.



13. A missile or other moving body comprising a rotatable
portion arranged for rotation relative to a main body portion of


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the missile or body and control means for rotating said rotatable
portion to bring it to any one of a plurality of preselected posi-
tions in relation to a datum and for exerting a thrust thereon
having a lateral component with respect to the axis of rotation of
said rotatable portion to produce a steering effect on the missile
or body, said control means-comprising a pair of aileron control
surfaces each of which is mounted on the rotatable portion for
rotation about an axis transverse to the rotary axis of the rota-
table portion, aileron actuator means responsive to a control
signal for turning said aileron control surfaces about their
rotary axes to deflected positions in which they produce a compo-
nent thrust on the rotatable portion causing it to rotate, a pair
of elevator control surfaces each of which is mounted on the
rotatable portion for rotation about an axis transverse to the
rotary axis of the rotatable portion, elevator actuator means
responsive to control signals for turning the elevator control
surfaces about their rotary axes to deflected positions in which
they exert a thrust on the rotatable portion in a direction away
from the axis of rotation thereof.



14. A missile according to claim 13, wherein said aileron
control surfaces are rotatable about their rotary axes between two
dispositions in the first of which the aerodynamic forces acting
on the aileron control surfaces produce a component thrust causing
rotation of said rotatable portion in one sense and in the second
of which the aerodynamic forces acting on the aileron control


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surfaces produce a component thrust causing rotation of said rota-
table portion in the opposite sense, and wherein said aileron
actuator means is responsive to control signals for turning said
aileron control surfaces about their rotary axes to the one or the
other of the first and second dispositions.

Description

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The present lnventlon relates to control systems for
movlng bodies and is partlcularly though not excluslvely concerned
wlth a remote control system for an aerlal body such as a mlsslle.
It ls well known that the cost of control equlpment used
in a mlssile represents an appreclable portlon of the total manu-
facturlng cost and that attempts are constantly belng made to
reduce the cost and also the bulk and welght of the e~uipment.
Such economies are partlcularly desirable in the case of small
missiles and it is one ob~ect of the present invention to provide
a simple control system whlch facilitates a substantial reductlon
in the cost, bulk and weight of the missile.
According to the present invention, there ls provided a
missile or other moving body comprising a rotatable portlon arran-
ged for rotation relatlve to another portlon of the missile or
body, means for rotatlng sald rotatable portion and brlnging it to
any one of a number of preselected posltlons ln relatlon to a
datum, and means on sald rotatable portion for exerting a thrust
thereon away from the axis of rotation to produce a steering
effect on the missile or body.
Two embodlments of the inventlon will now be descrlbed
by way of example with reference to the accompanying drawings in
whlch,
Fig. 1 ls a schematic perspective vlew of a mlssile
according to a flrst embodlment of the lnventlon,
Flg. 2 ls a part sectional slde elevation of a forward
portlon of the mlsslle shown ln Flg. l,



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Flg. 3 is a schematlc block dlagram of control apparatus
embodied ln the mlsslle shown in Fig. 1, and
Fig. 4 is a schematic dlagram of the front portlon of a
missile according to a second embodlment of the lnvention.
Referring first to Figs. 1 and 2, a mlssile 11 comprlses
a maln body portion 12, a nose portion 13 and a tall portion 14.
The tall portlon 14 carrles flxed body-stablllslng flns 15 and is
fixedly mounted on the maln body portlon 12. The nose portlon 13
lncludes a palr of elevator control surfaces 16 and 17 and a palr
of alleron control surfaces 18 and l9. As shown ln Flg. 2, the
nose portlon 13 ls rotatably mounted ln bearlngs 20 on the forward
end of the maln body portlon 12 and houses a free gyroscope 21
whlch ls arranged to generate an electrlcal slgnal representatlve
of the roll/attltude of the nose portlon. The elevator control
surfaces 16 and 17 are rotatably mounted ln bearlngs 22 for
rotatlon about a common lateral axis and the lnner ends of the
shafts supportlng the control surfaces 16 and 17 are provided with
eccentrically mounted pins 23 and 24 which engage in a peripheral
groove in the head of a push rod 25 which extends into the nose
portion 13 from the body portlon 12. Wlthln the body portlon 12
the push rod 25 is formed wlth a diaphragm 26 whlch serves as an
armature cooperatlng wlth a pair of solenoid colls 27 and 28
energlsed ln a manner herelnafter to be descrlbed, the arrangement
belng such that upon energlsation of the colls 27 and 28 ln one
sense the push rod 25 ls moved forward into the nose portion,
actlng on the eccentrlc plns 23 and 24 and serv~ng to brlng the


1336083 20239-511
elevator control surfaces 16 and 17 to a deflected posltlon, and
upon energlsation of the coils 27 and 28 ln the opposlte sense the
push rod is moved to a retracted posltion causlng the elevator
control surfaces 16 and 17 to move to a deflected position ln the
opposlte sense. The alleron control surfaces 18 and 19 are con-
trolled by a push rod 29 within which the push rod 25 is slidably
mounted, and the push rod 29 ls controlled ln the same manner as
the push rod 25 by the actlon of a palr of solenold colls 30 and
31 actlng on a dlaphragm 32 formed on the push rod 29, wlth the
exceptlon that the eccentrlc plns carrled on the supportlng shafts
for the alleron control surfaces 18 and 19 are 50 arranged that
the two control surfaces 18 and 19 move ln opposite senses to
deflected posltlons ln response to elther a forward or rearward
movement of the push rod 29.
The colls 27,28 and 30,31 are energlsed under the
control of apparatus 33 housed ln the maln body portlon 12 of the
mlsslle, and thls wlll now be descrlbed wlth reference to Fig. 3.
The control apparatus 33 comprlses a battery 34, two swltchlng
unlts 35 and 36, a slgnal comparator 37 and a slgnal receiver and
decoder 38. Energlslng current for the solenold coils 27 and 28
ls supplled by the battery 34 through swltch 35 whlch ls control-
led by a slgnal transmltted from a remote ground control station
and recelved by recelver 38. Energlslng current for the solenoid
colls 30 and 31 ls supplled by the battery 34 through the swltch
36 whlch ls controlled by the output from the comparator 37 whlch
compares the slgnal generated by the gyroscope Zl wlth a further


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20239-511
signal transmltted from the control station and recelved by the
recelver 38. Each of the switches 35 and 36 ls such that in a
flrst condition current from the battery 34 ls fed through the
solenold colls ln one sense and ln a second condltlon ls fed
through the colls in the opposlte sense.
In operatlon, the gyroscope 21 eeds to the comparator
37 a slgnal representatlve of the roll attltude of the nose
portlon 13 of the mlsslle. From the ground station two slgnals
are transmitted. One of these signals ls of the same form as that
generated by the gyroscope 21 but ls representatlve of a requlred
roll attltude for the nose portlon 13. The latter slgnal is
applied to the comparator 37 which produces an output slgnal
representative of the dlfference between this signal and the
slgnal from the gyroscope 21 and ln response to the output slgnal
from the comparator the swltch 36 ls operated so as to set the
alleron control surfaces 18 and 19 ln an attitude whlch wlll cause
the nose portion 13 to rotate from the present roll attitude to
the requlred roll attltude. As the nose portlon 13 approaches the
requlred roll attltude the two slgnals fed to the comparator 37
become equal and then differ from each other ln the opposlte sense
wlth the result that the output slgnal from the comparator 37
changes sign and causes the switch 36 to swltch over and move the
alleron control surfaces 18 and 19 to deflected posltlons causlng
rotatlon of the nose portlon 13 in the opposite sense. As the
frequency response of the alleron control surfaces 18 and 19 is
low in comparlson with the command frequency these surfaces then




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1336083
~ 20239-511
hunt about their undeflected positions wlth the result that the
nose portlon is held at the required roll attltude.
The other slgnal transmltted from the ground statlon and
received by the recelver 38 ls ln the form of a mark-space slgnal
and is applled to the swltch 35, whlch ln response thereto first
switches the elevator control surfaces 16 and 17 in one sense and
then ln the opposlte sense ln response to a change ln the mark-
space slgnal. The mark-space ratlo of the slgnal ls ad~usted at
the control station to a value whlch wlll result ln the elevator
control surfaces belng held ln one deflected posltlon for a tlme
greater than that for which they are held ln thelr other deflected
position and by virtue of this there will be produced on the nose
portlon 13 a net lateral thrust tendlng to steer the mlssile ln
the requlred dlrectlon.
Referring now to Flg. 4, ln a second embodlment of the
lnventlon the nose portlon 13 of the mlsslle ls rotatably mounted
on the forward end of the maln body portion 12 and is provided
with fixed aileron control surfaces 39 and 40 which serve to
impart to the nose portion 13 a constant rotatlonal force so that
the nose portlon 13 ls durlng fllght of the mlsslle normally
revolvlng wlth respect to the maln body portlon 12. The nose
portlon 13 also lncludes fixed elevator control surfaces (not
shown) set ln posltlons ln whlch they lmpart a lateral thrust on
the nose portlon. A gyroscope 21 ls mounted ln the nose portlon
and generates an output signal ln the same manner as the gyroscope
21 ln the embodlment herelnbefore descrlbed. The maln body


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portlon 12 of the mlssile houses a braking devlce 41 whlch ln
response to an input slgnal brlngs the nose portlon 13 rapldly to
rest wlth respect to the maln body portlon 12. A recelver and
decoder 38 ls also mounted in the maln body portion 12 and is
arranged to recelve two slgnals from a ground statlon one of which
serves as a braking slgnal for appllcation to the braking device
41 and the other of which ls of the same form as the signal gener-
ated by the gyroscope 21 but is representatlve of the requlred
roll attltude for the nose portlon 13. The latter signal is
applled to a comparator 37 whlch is of the same form as that
hereinbefore descrlbed and which serves to close contacts 42 such
that when the braking slgnal is applied to the braking devlce 41
the nose portlon 13 ls brought to rest in the requlred roll
attltude.
The lateral thrust imparted to the nose portlon ~y the
elevator control surfaces then becomes effectlve ln the re~uired
direction and the mlsslle is steered on to a preselected new
course. The magnitude of the manoeuvre re~uired may be ad~usted
by providing an on-off braklng slgnal and varylng the mark-space
ratlo of the slgnal.
In order to increase the effectiveness of the control
system in the embodiment descrlbed with reference to Fig. 1 the
main body portion 12 of the missile may be arranged to rotate in a
directlon opposlte to that of the nose portion 13 by blaslng the
four stabllising vanes 15 in the appropriate direction.




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133~083
- 20239-511
The two alleron control surfaces in the embodlment shown
ln Fig. 4 may be dispensed with by arranging that the two elevator
control surfaces act as ailerons when the brake 41 is released and
swltch back to act as elevators when the brake 41 is again
applied.




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