MISSILE CONTROL MECHANISM

MECANISME DE CONTROLE DE MISSILE

English Abstract

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
applied thereto for turning said control surface about its rotary axis to a
first disposition in which it produces a component thrust causing rotation
of said rotatable portion, and a second disposition in which it produces a
lateral steering force on the missile.

Claims

8

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 a main body portion of the missile or body, and
means for rotating said rotatable portion to bring it to any one of a number
of preselected positions in relation to a datum and for exerting a thrust
thereon away from the axis of rotation to produce a steering effect on the
missile or body, said means comprising a control surface pivotally mounted
on the rotatable portion on one side thereof for rotation about a lateral
axis, an actuating mechanism for turning said control surface in one sense
to a first deflected position and in the opposite sense to a second deflected
position, and a fixed control surface fixedly mounted on the other side of
the rotatable portion at a predetermined angle of incidence, the arrangement
being such that the movable control surface pivots from one of its two de-
flected positions to the other through an angle which is divided by the
plane containing the fixed control surface and the pivotal axis of the
movable control surface.


2. A missile or other moving body comprising a rotatable portion arranged
for rotation relative to a main body portion of the missile or body, and
means for rotating said rotatable portion to bring it to any one of a number
of preselected positions in relation to a datum and for exerting a thrust
thereon away from the axis of rotation to produce a steering effect on the
missile or body, said means comprising a first movable control surface pivo-
tally mounted on the rotatable portion on one side thereof for rotation
about a lateral axis, a second movable control surface pivotally mounted on
the rotatable portion on the other side thereof for rotation about the same
lateral axis as the first control surface, and an actuating mechanism to
cause said first movable control surface to turn between first and second
deflected positions and the second movable control surface to turn between
said positions in the same manner as but in the opposite direction to said
first movable control surface, each movable control surface in pivoting
from one of its two deflected positions to the other being moved through an




angle which is divided by a plane inclined at a predetermined angle of
incidence and containing the pivotal axis of the movable control surface moved.


3. A missile according to claim 1, wherein the said angle through which
the movable control surface pivots is equally divided by said plane.


4. A missile according to claim 3, wherein the movable control surface
or each movable control surface has a positive angle of incidence greater
than said predetermined angle of incidence in one of its deflected positions
and a positive angle of incidence less than said predetermined angle of
incidence in its other deflected position.


5. A missile according to claim 4, wherein said actuating mechanism is
movable in response to the energisation of an electromagnetic coil or coils
forming part of the mechanism and contained in the main body portion of the
missile, wherein said coil or coils are mounted in the body portion concen-
tric with respect to the rotary axis of the rotatable portion, and wherein
said actuating mechanism comprises an axially movable shaft co-axial with
the rotary axis and extending at one end into the rotatable portion and at
the other end carrying an armature disc mounted concentrically with respect
to the shaft and in cooperating relation with said coil or coils which upon
energisation causes or cause the disc and the shaft to move axially to effect
actuation of the movable control surface.


6. A missile according to claim 5, said shaft and armature disc being
rotatable about the rotary axis of the rotatable portion of the missile.


7. A missile according to claim 5, wherein the actuating mechanism in-
cludes a spool provided on the end of the shaft, said spool being co-axial
with the rotary axis of the rotatable portion and being engaged by a pin
which is carried by the movable control surface, the pin slidably engaging
in a peripheral groove in the spool and being constrained thereby to follow
the axial displacement of the spool whilst rotating with the rotatable portion.


8. A missile according to claim 7, wherein the pin engaging the spool



is carried by a supporting shaft for the movable control surface in such
a manner that axial displacement of the spool causes a pivotal turning
movement of the movable control surface.


9. A missile according to claim 1, wherein said actuating mechanism
is arranged to be operated by control apparatus in the missile, said control
apparatus comprising a gyroscope mounted in the rotatable portion of the
missile and arranged to generate a signal representative of the attitude
of the rotatable portion with respect to a predetermined datum roll attitude
in space, a receiver mounted in the missile for receiving a control signal
from a remote control station representative of a required roll attitude
for the rotatable portion with respect to said datum attitude, a comparator
to which the signal generated by the gyroscope and the signal received from
the control station are applied to produce a switching signal the sign of
which represents the direction in which the rotatable portion is required
to turn to reach the required roll attitude, and a switch for controlling
the energisation of the actuating mechanism and responsive to said switching
signal to cause movement of the movable control surface to the appropriate
deflected position in response to a switching signal of one sign and to
cause movement of the movable control surface to the other deflected posi-
tion in response to a switching signal of opposite sign.


10. A missile according to claim 9, wherein means are provided for
modifying the switching signal in response to a lateral demand signal trans-
mitted from the remote station so that by an increase in the amplitude of
the signal applied to the switch the movable control surface is held for
longer times in its deflected positions resulting in an increase in the
amplitude of the roll oscillation of the rotatable portion and producing
a smaller mean steering effect on the missile and by a decrease in the
amplitude of the signal applied to the switch the movable control surface
is held for shorter times in its deflected positions resulting in a decrease
in the amplitude of the roll oscillation of the rotatable portion and a
greater mean steering effect on the missile.


11

11. A missile according to claim 1, wherein said first rotatable portion
is constituted by a nose portion of the missile which is mounted for rota-
tion about the longitudinal axis of the missile on the forward end of the
main body portion of the missile.


12. 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 applied thereto for turning said control
surface about its rotary axis to a first disposition in which it produces
a component thrust causing rotation of said rotatable portion, and a second
disposition in which it produces a lateral steering force on the missile.


13. A missile or other moving body comprising a rotatable portion
arranged for rotation relative to another portion of the missile or body,
a first aerodynamic control surface fixedly mounted on the rotatable portion
at a predetermined angle of incidence, a variable-incidence aerodynamic
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 variable-
incidence control surface about its rotary axis to bring it to either of two
dispositions in each of which it produces with said fixed control surface
a thrust on said rotatable portion having a lateral component with respect
to the axis of rotation of said rotatable portion to produce a steering
effect on the missile, in one of which it produces with said fixed control
surface a component thrust causing rotation of said rotatable portion in
one direction and in the other of which it produces with said fixed control

12

surface a component thrust on said rotatable portion causing rotation of
said rotatable portion in the opposite sense.


14. A missile or other moving body comprising a rotatable portion
arranged for rotation relative to another portion of the missile or body
about a longitudinal axis of the missile or body, a pair of variable-
incidence aerodynamic control surfaces 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 surfaces about their rotary axes between two dis-
positions in each of which the control surfaces produce together a thrust
on said rotatable portion having a lateral component with respect to the
axis of rotation of said rotatable portion to produce a steering effect on
the missile, in one of which they produce a component thrust causing rota-
tion of said rotatable portion in one direction and in the other of which
they produce a component thrust on said rotatable portion causing rotation
of said rotatable portion in the opposite direction.


15. A missile according to claim 14, wherein each variable-incidence
control surface pivots from one of its dispositions to the other through
an angle which is divided by a plane inclined at a predetermined angle
of incidence and containing the pivotal axis of the variable-incidence
control surfaces.


16. A missile according to claim 15, wherein the said angle through which
each control surface pivots is equally divided by said plane.



17. A missile according to claim 16, wherein each control surface has
a positive angle of incidence greater than said predetermined angle of
incidence in one of its two deflected positions and a positive angle of
incidence less than said predetermined angle of incidence in its other
deflected position.


18. A missile according to claim 17, wherein said actuating mechanism
is arranged to be operated by control apparatus in the missile, said control


13

apparatus comprising a gyroscope mounted in the rotatable portion of the
missile and arranged to generate a signal representative of the attitude
of the rotatable portion with respect to a predetermined datum roll attitude
in space, a receiver mounted in the missile for receiving a control signal
from a remote control station representative of a required roll attitude,
a comparator to which the signal generated by the gyroscope and the signal
received from the control station are applied to produce a switching signal
the sign of which represents the direction in which the rotatable portion
is required to turn to reach the required roll attitude, and a switch for
controlling the energization of the actuating mechanism and responsive to
said switching signal to cause movement of each control surface to the
appropriate deflected position in response to a switching signal of one
sign and to cause movement of each control surface to the other deflected
position in response to a switching signal of opposite sign.


19. A missile according to claim 14, wherein said first rotatable portion
is constituted by a nose portion of the missile which is mounted for rota-
tion about the longitudinal axis of the missile on the forward end of
the main body portion of the missile.


20. A missile according to claim 14, wherein said actuating mechanism
is movable in response to the energization of an electromagnetic coil or
coils forming part of the mechanism and contained in the main body portion
of the missile, wherein said coil or coils are mounted in the body portion
concentric with respect to the rotary axis of the rotatable portion, and
wherein said actuating mechanism comprises an axially movable shaft coaxial
with the rotary axis and extending at one end into the rotatable portion
and at the other end carrying an armature disc mounted concentrically with
respect to the shaft and in cooperating relation with said coil or coils
which upon energization causes or cause the disc and the shaft to move
axially to effect actuation of the variable-incidence control surfaces


21. A missile according to claim 20, wherein the shaft and armature
disc are rotatable about the rotary axis of the rotatable portion of the


-14-

missile


22. A missile according to claim 21, wherein the actuating mechanism
includes a spool provided on the end of the shaft, said spool being coaxial
with the rotary axis of the rotatable portion and being engaged by a pin
which is carried by each control surface, each pin slidably engaging in
a peripheral groove in the spool and being constrained thereby to follow
the axial displacement of the spool whilst rotating with the rotatable
portion.


23. A missile according to claim 22, wherein each pin engaging the
spool is carried by a supporting shaft for the control surface in such a
manner that axial displacement of the spool causes a pivotal turning
movement of the movable control surface.

Description

1336085
20239-542
The present lnvention relates to control systems for
movlng bodles and ls partlcularly though not exclusively
concerned with a remote control system for an aerlal body such
as a missile.
In our copending Canadian Patent Applicatlon No.
904308/64 there ls clalmed a mlsslle or other moving body
comprising a rotatable portlon arranged ior rotation relatlve
to another portlon of the misslle or body, means for rotatlng
sald rotatable portlon and brlnging lt to any one of a number
of preselected positlons in relation to a datum, and means on
sald rotatable portlon for exertlng a thrust thereon away from
the axls of rotatlon to produce a steerlng effect on the
mlsslle or body.
It ls well known that the cost of control equlpment
used ln a misslle represents an appreclable portlon of the
total manufacturlng cost of the missile and attempts are
constantly belng made to reduce the cost and also the bulk and
weight of the control equlpment. Such economies are particu-
larly desirable in the case of small mlssiles and although the
misslle formlng the sub~ect of our copendlng patent appllcation
effects useful economies ln this directlon lt ls an ob~ect of
the present invention to provide an improvement in or modlflca-
tion of the mlsslle formlng the sub~ect of the copendlng appll-
catlon, ln which the amount of control equlpment is still
further reduced.
Accordlng to the present inventlon, there ls provlded
a misslle or other movlng body comprlsing a rotatable portlon
arranged for rotation relatlve to another portion of the
mlsslle or body, and means for rotating sald rotatable portlon
to brlng lt to any one of a number of preselected posltlons ln
relation to a datum and for exertlng a thrust thereon away from



3 133~08~
- 20239-542
the axls of rotatlon to produce a steering effect on the
misslle or body.
One embodiment of the inventlon wlll now ~e described
by way of example with reference to the accompanying drawings
in whichs-

Fig. 1 is a side elevation of a misslle accordlng tothe invention,
Flg. 2 is a part sectional plan view of a portlon of
the missile shown in Flg. 1,
Fig. 3 ls a block schematic diagram of control
apparatus housed in the mlsslle,
Fig. 4 ls a block schematic dlagram of part of the
apparatus shown ln Flg. 3 includlng details of the contents of
one of the unlts illustrated in Fig. 3, and
Flg. 5 is a schematic perspectlve view of an alter-
native arrangement of the control surfaces of the missile,
Referring first to Flgs. 1 and 2, a mlsslle 11
comprlses a maln body portion 12 and a nose portlon 13 which is
rotatably mounted in bearlngs 14 on the forward end of the maln
body portlon 12 for rotation about the longltudinal axis of the
missile 11 and which houses a free gyroscope 15 whlch ls
arranged to generate an electrlcal slgnal representatlve of the
roll attltude of the nose portlon. The nose portlon 13 ls
provided with a control surface 16 mounted in the nose portion
13 for rotation about a lateral axis passlng through the
longitudinal axis of the missile 11, the lnner end of a shaft
17 supporting the control surface 16 belng provlded wlth an
eccentrlcally mounted pin 18 which engages in a peripheral
groove 19 in a head 20 of an axially movable push rod 21
coaxial with the rotary axis of the nose portion 13 and exten-
ding at one end lnto the rotatable nose portlon 13 and at the



133 ~ 20239-542
other end carrying an armature dlsc 22 mounted concentrlcally
wlth respect to the push rod 21 and arranged between and in
cooperatlng relation wlth a pair of actuator solenolds 23 and
24 mounted ln the main body portion 12 and coaxial with the
longltudinal axis of the missile 11, the arrangement being such
that upon energisatlon of the solenoid 23 the push-rod 21 is
moved orward into the nose portion 13 acting on the eccentri-
cally mounted pin 18 and causing the control surface 16 to be
angularly turned in one sense to a flrst deflected position and
upon energlsation of the solenoid 24 the push-rod 21 is moved
rearward causlng the control surface to be angularly turned in
the opposite sense to a second deflected position.
A fixed surface 25 of the same shape and size as the
movable control surface 16 ls fixedly mounted on the other side
of the nose portlon 13 at a predetermlned angle of lncidence
and the arrangement is such that the movable control surface 16
plvots from one of its two deflected positions to the other
through an angle which ls equally dlvided by the plane contain-
ing the fixed surface 25 and the plvotal axis of the movable
control surf~ce 16, the movable control surface 16 moving to a
large angle of incidence at one of lts deflected posltlons,
herelnafter referred to as the high lncidence position, and
movlng to a low angle of lncldence at its other deflected
posltlon, hereinafter referred to as the low incidence
position.
The two solenoids 23 and 24 hereinbefore referred to
are energised under the control of apparatus housed ln the main
body portion 12 of the missile ll. The control apparatus is
shown in Fig. 3 and includes a battery 26 for supplying energl-

slng current to the solenolds 23 and 24 through a changeoverswltch 27 ln a flrst positlon of whlch one of the solenolds 23


-



133~08~
20239-542
and 24 is energlsed and ln a second posltlon of whlch the other
of the solenolds 23 and 24 ls energised. A roll-posltlon
comparator 28 ls provlded whlch compares the slgnal generated
by the gyroscope 15 wlth a roll-demand slgnal transmltted from
the remote control ground statlon and fed to the comparator 28
from a slgnal recelver and decoder 29. The output from the
comparator 28 ls fed to a roll loglc clrcuit 30 as descrlbed ln
our French Patent Application based on ~rltlsh Patent Appllca-
tlon No. 50198/64, the output of which is fed via a roll-

amplitude comparator 31 to the changeover switch 27, which inresponse thereto swltches to the one or other of its two
positions accordlng to whether the slgnal from the roll logic
circuit 30 ls posltlve or negatlve, and the arrangement ls such
that the changeover swltch 27 ls moved to a posltlon whlch will
cause by energlsatlon of the approprlate solenold and the
approprlate settlng of the movable control surface 16 at one of
lts two deflected positions rotatlon of the nose portlon 13 vla
its shorter path to the required roll attitude, whereupon the
output from the roll logic circuit becomes zero and changes
slgn, causlng the changeover swltch 27 to switch over with the
result that the other solenoid becomes energlsed. The movable
control surface 16 moves to lts other positlon and the nose
portion rotates ln the opposlte sense. The movable control
surface 16 then hunts about its undeflected positlon and the
nose portion 13 is held at the required roll attltude.
A lateral demand slgnal is transmitted from the
ground statlon ln the form of a mark-space slgnal and is
converted ln the decoder 29 to a direct current signal which is

applled to the roll-amplitude comparator 31 which in response
thereto modlfies the amplltude of the output from the loglc


_ _ _ _

~ 1336085
2023g-542
clrcult so that, for example, by an increase ln the amplitude
of the slgnal applied to the changeover switch 27, the movable
control surface 16 ls held for longer times ln lts deflected
posltlons whlch results in an lncrease ln the amplltude of the
nose roll osclllatlon and produces a smaller mean steering
effect on the missile.
Referrlng now to Flg. 4, the roll amplitude compara-
tor 31 takes the form of a Schmidt trlgger clrcult wlth back-
lash, wlth the amount of backlash belng varled by the output
from the decoder 2g. The output of the Schmldt trlgger clrcult
feeds the swltch 27 which operates the solenoids 23 and 24 in
antl-phase. As shown, the roll amplitude comparator 31 compri-
ses an adder unit 32, a zero-level Schmidt trlgger clrcult 33
and a slgn modulator 34. The trlgger clrcult 33 ls arranged to
have an output which is posltlve for posltive lnputs thereto
and negative for negative inputs thereto. the output slgnal
from the trlgger clrcult 33 is fed to the sign modulator 34 so
that the slgn of the output slgnal ls glven to the roll ampli-
tude demand output of the decoder 29, whlch ls then summed ln
the adder unlt 32 wlth the output of the roll loglc clrcul~ 30
and the summed slgnal applled as an lnput to the Schmidt
trlgger clrcuit 33.
In an alternatlve embodlment of the lnventlon shown
ln ~lg. 5 the fixed surface ls replaced by a second movable
control surface 35 whlch pivots ln the same manner and through
the same angle as that through which the control surface 16
plvots, but which is operated by a further eccentrlcally moun-
ted pln 36 so arranged as to cause the second control surface
35 to move wlth but ln opposlte sense to the flrst control
surface 16, whereby when the flrst control surface 16 moves to

1336085
20239-542
the hlgh lncldence posltlons the second control surface 35
moves to the low lncldence posltlon and when the first control
surface 16 moves to the low lncldence position the second
control surface 35 moves to the hlgh lncldence posltlon.