US2433837A

US2433837A - Gyro-controlled stabilizing system

Info

Publication number: US2433837A
Application number: US516896A
Authority: US
Inventors: John W Dawson
Original assignee: Raytheon Manufacturing Co
Current assignee: Raytheon Co
Priority date: 1944-01-03
Filing date: 1944-01-03
Publication date: 1948-01-06
Anticipated expiration: 1965-01-06

Description

GYRO-CONTROLLED STABILIZING 'SYSTEM Filed Jan. 3, 1944 3 Sheets-Sheet l servo #MPL/MM' SYNC/1K0 SER v0 ,ama/nc@ MVN/TM. Jo/7W if. mmm,

Jan. 6, 1948. L W, DAWSON 2,433,837

GYRO- CONTROLLED STABILI Z ING SYSTEM Filed Jan. 5, 1944 5 Sheets-Sheet 2 M0 70A 40 a Jan 6, 1948 J. w. DAWSON 2,433,837

GYRO-CONTROLLED STABILIZING SYSTEM Filed Jan. 3, 1944 I5 Sheets-Sheet 3 /A/VEA/TOR. dof/v W. mrsa/V,

Mwf 'Patented Jan. 6, 1948 Grao-CONTROLLED s'rABrLrzTNo SYSTEM John W. Dawson, West Newton, Mass., assigner to Raytheon Manufacturing Company, Newton, Mass., a corporationof Delaware Application January 3, 1944, Serial No. 516,896

14 Claims. (Cl. 318-19) This invention relates to a stabilizing system for maintaining the position of an object, such as a directionally radiating antenna, aimed in a predetermined direction under conditions in which the support for such an object, such as a deck of a ship, may be subjected to a haphazard variation in its position.

An object of this invention ls to devise such a stabilizing system which is simple, rugged and reliable.

Another object is to devise such a system ln which a gyroscope mounted in gimbals, directly and mechanically stabilizes the position of a second gimbal system on which the stabilizing control elements are mounted.

A further object is to devise a simple lever arm arrangement for connecting the two gimbal systems in such a way that one of said gimbal systems may rotate freely with respect to the other.

A still further object is to incorporate in such a system an angle computing mechanism which introduces a correction into the azimuthal position of the controlled object, which compensates `for the tilt of the carrier of the controlled object, such carrier being, for example, the deck of a ship.

The foregoing and other objects of this invention will be best understood from the following description -of exemplications thereof, reference being had to the accompanying drawings where- 1n:

Fig. 1 is a diagram of one form of my invention applied to an arrangement for maintaining the line of sight of the controlled object fixed on the horizon in a predetermined azimuthal angle;

Fig. 2 is a circuit diagram of one portion of the arrangement shown in Fig. 1;

Fig. 3 is a circuit diagram of another portion of the arrangement shown in Fig. 1; and

Fig. 4 is a diagram of another form of angle computer for my invention as applied to an arrangement for maintaining the line of sight of the controlled object at a fixed azimuthal angle and at a fixed angle of elevation about the horizon.

In the arrangement shown in Fig. 1, a controlled object I, such as a directional radiating antenna system for radiating super-high frequency waves, is to be controlled so as to maintain its line of sight intersecting a fixed point on the horizon. The controlled object, which is mountedy in a frame 2, is fixed to a pair of shafts 3 which are rotatably mounted in the side portions of said frame member. The shafts 3 estab-l lish an axis which is termed the tilting axis of the like.

the controlled object I. The frame 2 is mounted on a vertical shaft 4 which is driven by a motor `5 supported on a base 6 which is fixed to some movable carrier, such as a deck of a ship or The axis of rotation of the vertical shaft 4 is herein termed the azimuthal axis.

The controlled object I, which may be set with its line of sight intersecting a predetermined point on the horizon by means which will be described below, is maintained in its set position despite the pitch and roll of the ship upon which it is mounted by the action of a stabilizing system. This stabilizing system includes a gyroscope 1 of the self-erecting type mounted in gimbals including a frame member 8 fixed to a supporting base 9, likewise mounted upon the same carrier which carries the supporting member 6. The gimbals also include a ring member I0 in which the gyrosccpe 1 is pivoted on pivots II. The ring member I8 is in turn pivoted to the frame member 8 at pivots I2. The axis extending through the pivots I2 is substantially at right angles tothe axis extending through the pivots II.

Associated with the gyroscope 1 is an angle computer mechanism I3 which includes a synchro I4. The synchro I4 comprises a frame member I5 within which is contained an armature member carried by a shaft I6 rotatable in the frame member I5. The right hand portion of Fig. 2 illustrates diagrammatically the interior connections of the synchro I4. In Fig. 2, I1 represents a closed winding carried by the frame member I5. The shaft I6 carries an armature I8, upon which is provided a winding I9. Referring again to Fig. 1, the frame member I5 is fixed upon a pair of shafts 20 which are rotatably mounted in a ring member 2| of another gimbal system. The ring member 2I is pivoted to a frame member 22 about an axis substantially perpendicular to the axis extending through the shafts 20. The frame member 22 is mounted on a vertical shaft 23 which is rotatably supported in a bearing member 24 xed to the support 9. The top of the gyroscope 1 is provided with a pair of arms 25 fixed to and projecting upwardly from said gyroscope. If desired, a cross arm 26 may be pro- I vided to brace the upper portions of the arms 25.

aasassv by gears 29 and 80, the gear 3| being fixed on the shaft 23. The motor 28 is energized from a pair of output conductors II of a suitable servo amplifier 32 supplied with power from a pair of leads 33 connected to a suitable source of alternating current. The servo amplifier 32 may be of the type as described and claimed in my copending application, Serial No. 509,631, nled November 9, 1943, now Patent 2,423,438, dated July 15, 1947, in which the magnitude and direction of the voltage supplied to the leads 3l are dependent upon the magnitude and phase of a control voltage supplied to the input conductors 34 of the servo amplifier. In the present arrangement the conductors 34 are connected to the ends of the armature winding I! of the synchro I4. Thus it will be seen that the output signal `from the synchro I4 will control the speed and direction of rotation of the motor 2l. Under these 4 vided with an armature mounted upon the shaft I which also carries a gear I1. Said gear l1 meshes with a gear l carried upon the shaft of motor Il whose frame is likewise fixed to the frame 2. The signal voltage generated within thesynchro llisfedbymeansofapairotleads 4I to a servo amplifier GI. the output of which is fed by means of conductors I2 to the motor Il. The s ervoampliner ll is similar to the servo amplifier l2 and is likewise supplied with power from a pair of leads t3 which are preferably connected to the same source oi! alternating current as the leads 83 of the servo ampliner 32.

Certain aspects of the operation of the system show'n in Pig. i will be more clearly understood by referring to the electrical diaa'ram in Fig. 2. As illustrated in this figure. the compass synchro Il comprises a closed stator winding Il which is mounted upon a suitable stator member conditions the motor 28 drives the frame member ,o nxed to and carried by the ship. The compass 22 and thus the frame member I5 of the synchro I4 to a position in which the amature It is at right angles to the magnetic field of the winding l1, under which conditions substantially no output signal voltage is supplied to the conductors 34. This position of the armature Il. with respect to the magnetic field 'of the winding I1 may be termed the zero position of the synchro I4. The position of the magnetic field of the winding I1 is controlled in a manner to be described below by a compass synchro I5 which feeds into an azimuthal control diiferential synchro 36 which in turn feeds into the winding I1 of the synchro I4.

A synchro 31 is associated with the angle computer mechanism I3 to transmit the proper az'imuthal control to the controlled object I. The synchro 31 is provided with a frame-member 3l fixed to the support 9 and with an armature member mounted on a rotatable shaft 4I. The shaft has secured thereto a gear 4I which engages with the gear 30 fixed to the shaft-23. The synchro 31 feeds into a synchro 42 having a frame member 43 xed to the support 5 and an armature mounted on a rotatable shaft 44. The shaft 44 is geared by means of gears 45 to the shaft 4. A signal voltage, developed in the synchro 42 as will be explained below, is fed through a servo amplifier 46, similar to the servo amplifier 32, and by output conductors 41 extending from the servo amplifier 46, to the motor 5. The servo amplifier 4S is supplied with power from leads 4l preferably connected to the same source of alternating current as the leads 33 of servo amplifier 32.

The tilting of the controlled object I about its tilting axis is controlled by a synchro 4l whose frame member is fixed to the frame member 22 of the angle computer I3. The synchro 43 is likewise provided with an amature mounted on a rotatable shaft. 5I to which is nxed a gear 52. The gear 52 meshes with a rotatable gear I3 carried by an arm of the frame member 22 and rotatable thereon. The gear member 53 engages with a. gear 54 fixed to and rotatable with the ring member 2|, as said ring member rotates about its horizontal axis which is at right angles to the axis of the shafts 20. Thus, tilting of the ring member 2| about said horizontal axis will produce a corresponding rotation of the shaft 5I and the armature of the synchro 49 mounted thereon. The output of the synchro 4I feeds into a synchro 55 whose frame member Il is fixed to the frame 2. 'I'he synchro 55 is likewise prosynchro 3l also is provided with a rotatable armature Il carrying an armature winding 53 supplied with exciting alternating current through a pair of leads l1 connected to the saine alternating current source as the leads 33 of the servo amplifier I2. The armature Il is adapted to be rotated by a compass card Il which thus maintains the amature Il in a predetermined aaimuthal position, usually a north and south position. as the stator winding 44 moves with changes in the position of the ship. The diiferential synchro II associated with the compass synchro 35 is likewise provided with a stator winding Il carried by a suitable stator member. The diiferential synchro 3l is also provided with an armature 1l rotatable in the field of the stator winding 6I and carrying a closed armature winding 1I. Three equally-spaced points on the winding 1I are connected to three corresponding slip rings 12 upon which bear brushes connected to three conductors 13 extending to three similarly equally-spaced points 1I' on the stator winding 04 of the compass synchro 35. The armature 1l is rotated with respect to the winding t! by means of a controlling member 14, such as a handcrank. Of course it is to be understood that this controlling member may take any other form which is well known in position control systems. Three equally-spaced points 1I on the stator winding Il are connected by means of conductors 1t to three similarly equally-spaced points 11 on the winding I1 oi' the synchro I4.

The alternating current field of the armature Il induces voltages in the stator winding O4 which are transmitted by the conductors 13 to the armature winding 1I and reproduce a magnetic field in the space within the stator of synchro 33 which has the same angular orientation with respect to the three points on the winding 1I connected to the slip rings 12 as the three points 13' have with respect to the position of the armature Il. Thus, as the stator winding i4 turns with respect to its armature Il, the neld reproduced by the winding 1I will likewise turn with respect to said winding 1I to the same angular extent as the stator winding I4 turns with respect to'its armature !5. When the controlling memberl 14 physically turns the winding 1I, such motion is superposed on the above described motion of the neld 1I, and thus the absolute motion or position o! the field created by the armature winding 1I, with respect to its stator winding Il, is the resultant of the motion of the winding I4 and of the controlling member 14. 'I'he alterhating neld created by the armature winding 1I I'1 as the magnetic eld oi the winding 1I bears to the three points 15 on the winding 89. Unless the armature I9 is substantially at right angles to the field of the winding I1, a signal voltage will be generated in the winding I9.v -This voltage will be a measure ofv the deviation oi the armature I8 from its desiredzero position. This signal voltage, as already described, when fed to the servo amplifier 32 causes a current of the proper magnitude and direction to be supplied to the motor 28 so as to drive the winding I1 to' a position in which the armature I8 is atright angles to the magnetic eld of the winding I1.

Upon referring to Fig. 1, it will be seen that the above described motion producedlby the motor 25 is'imparted to the frame member 22 about the vertical axis of the shaft 23. It is desired that this motion likewise be transmitted to the controlled object I so as to control its azimuthal 6 For purposes of analysis we may assume that. at a particular time, the ship carrying the above described stabilizing system is motionless and lthe controlled obiect I is set with its line of sight intersecting a point on the horizon. -In order to set'the line of sight of the object I in some other predetermined azimuthal angle, the controlling object 14fis rotated through the desired angle and this rotation is transmitted through the synchros 35 and I4 to cause the motor 28 to drive the frame 22 through the same angle. This vangular motion is transmitted through synchros position. This action will be more clearly understood by referring to Fig. 3 which represents the electrical circuit between the

synchros

31 and 42, together with the associated motor 5. The syn chro 31 is provided with a closed stator winding 18 carried by the frame member 33 of the synfchro 31. Said synchro 31 is also provided with an armature 19 carried by the shaft 40. The armature 19 is provided with a winding 80 vwhich is supplied with alternating current from a pair of lead-in conductors 8| which are connected to the same source of alternating current as the conductors 48 of the servo amplifier 49. Three equally-spaced points on the winding 18 are connected to three equally-spaced points on the stator winding 82 of the synchro 42. The stator winding 82 is carried by the frame member 43 of said synchro 42. The synchro 42 is also provided with an armature 83 carried by the shaft 44, which as already described is driven by the mo-y tor 5 through Ia suitable gear drive 45. The armature 83 is likewise provided with a winding 84 which delivers a signal voltage through the conductors to the servo amplifier 43. As is well known in such a synchro system, the eld of the armature 19 will be reproduced by the winding 82 of the synchro 42, and the signal voltage delivered by the leads 85 will be a measure of the deder these conditions the servo amplier 45 will supply current of proper magnitude and polarity to the motor 5 so as to drive the armature 83 to its zero position.

,The tilting'of the controlled object I is con trolled by the

synchros

49 and 55 and by the associated motor 53. The circuit of the

synchros

49 and 55 and their associated motor 59 is identical with the circuit arrangement of the

synchros

31 and 42 and their associated motor 5. Therefore the arrangement as shown in Fig. 3 and the description given above in connection therewith apply wtih equal changes to the syn-

v xchros

49 and 55 and their associated motor 59.

Thus it will be seen that as the armature of the synchro 49 is turned by the shaft 5|, motor 59 will drive armature of synchro to its zero p0- sition and produce a corresponding tilting of the controlled object I about the axis of its shaft 3.

31 and 42 causing motor 5 to drive the frame 2 through the same angle and thus the controlled object I is set in the desired azimuthal position as fixed .by the setting o! the controlling object 14. If the ship changes its azimuthal position, the compass synchro 35 will cause its armature 55 to move through Ythe same angle as that through which the ship moves. This angle will be transmitted through

synchros

35, 35 and I4 to cause motor 28 to drive the frame 22 through the same angle. This motion in turn will be transmitted through

synchros

31 and 42 and their associated motor 5 to the frame 2. Thus having once fixed the controlled object I with its line of sight in a predetermined azimuthal angle, the compass synchro 35 will compensate for all azimuthal variations in the position of the ship and cause the controlled object I to ,be maintained with its line oi sight in said ,predetermined azimuthal position.

As the ship pitches and rolls the gyroscope 1 will maintain the arms 25 in a vertical plane and the connection to the shaft I5 by Vmeans of the tie rods 21 will likewise maintain the shaft I5 in a vertical plane and will also prevent said shaft from twisting about its own longitudinal axis with respect to the tie rods 21. It the ship tilts in a plane parallel to the vertical plane containing the line of sight of the controlled object I, the shaft I5 remaining vertical will cause the frame 22 to tilt with respect to the ring 2l. The angle through which such relative motion occurs will be transmitted through the

gear train

52, 53, 54 to the shaft 5I which will therefore rotate the armature oi' the synchro 49 through the same angle. The motion of the armature oi' the synchro 49 will transmit said angle to the synchro 55and therefore motor 59 in driving the armature of synchro 55 to its zero position will' I of sight of said controlled object will .be maintained iixed on the horizon.

If the ship tilts in a plane parallel to a vertical plane at right angles to the line of sight of the controlled object I, no compensation is needed.

. `Under these conditions the ring 2l and the frame 22 as a unit will tilt about the axis of the shafts 29. As will be noted, this does not shift the settings of any of the synchros and thus no compensation will be introduced into the system under these conditions.

' Ii' the ship tilts in a plane at an angle to either of the above defined vertical planes, the synchro 4 9 will transmit the component of that tilt which occurs in the vertical plane containing the line of sight of the controlled object I and will discard the component which lies in the vertical plane at right angles to said line of sight. y 'Iilting oi the ,ship in the last defined direction requires an 7 additional degree of azimuthal compensation in order for the line of sight of the controlled object I to be maintained in the desired direction. Such an azimuthal compensation is introduced di-- rectly by the synchro I4. If the ship moves in the last defined manner, a twist will occur bctween the stator I and the shaft II of the synchro I4. The angle of this twist will be exactly equal to that which must be imparted to the azimuthal position of the controlled object I to keep its line of sight fixed in its desired azimuthal angle and intersecting the horizon. As described above such a relative angular motion between the shaft I6 and its stator I5 will cause motor 5 to introduce an equal angular shift in the azimuthal position of the controlled object I.

The total result of the above described compensations is that the line of sight of the above controlled object I may be fixed by the controlling member 14 on any predetermined azimuthal point on the horizon and said line of sight will be maintained at that point irrespective of any motion of the ship.

Since in the above-described system the

synchros

35, 31, and 49 transmit an angular position from one point to a relatively remote point, synchros of this type may be termed transmitting synchros. The synchros Il, I2, and 55 receive signal currents from the transmitting synchros and therefore may be termed receiving synchros. Synchro 36 receives signal currents from transmitting synchro 35 and superimposes upon the angular position thus established an additional angular position as determined by the controlling member 14. For this reason synchro 36 represents a type which may be termed a differential synchro. Since synchro 36 also transmits the resultant angular position to the synchro I4, such a differential synchro can also be considered as a type of transmitting synchro.

In some cases it is desirable to keep the line of sight of the object I fixed in a predetermined azimuthal position with a fixed angle of elevation above the horizontal. An angle computer for accomplishing the foregoing is shown in Fig. 4 in which the same reference numerals as occur in Fig. 1 are applied where the elements are identical with those of Fig. 1. In Fig. 4 synchro I4 is carried on its shafts 20 rotatably mounted in an inner ring member 86. This inner ring member is carried rotatably by

shafts

81 and 88 mounted in an outer ring member 2|. The axis of the

shafts

81 and 38 is substantially perpendicular to the axis of shafts 20. The outer ring member 2I is pivoted, as described in Fig. 1, to the frame member 22 along an axis substantially at right angles to the axis of shafts 20 and substantially parallel with the axis of

shafts

81 and 88. The shaft 88 is geared by

gears

39 and 90 to the rotor of a synchro 9i. This synchro is substantially identical with the synchro I2 as described in connection with Figs. 1 and 3. The synchro 9| has a stator 92 which is fixed to the ring member 2|. The input to the synchro 3i is supplied from a synchro 93 which is substantially identical with synchro 31 described in connection with Figs. 1 and1- 3 except that the position of its armature is'controlled by a suitable controlling member S45-of the same type as the controlling member 1 The synchro 33 is provided with input lead 95 connected to a source of alternating current which is the same as that connected to the leads 63 of the servo amplifier 6I. The synchro 93 is also provided with input leads 96 leading to the stator of synchro SI. The

signal voltage developed in the synchro II is fed through output leads 91 to a servo amplifier Il. similar to servo amplifier I2. The servo amplifier 38 is supplied with power from leads Il connected to the same alternating current source as the leads 35 of the synchro 33. The output of the servo amplifier 33 is fed through leads Ill t0 a motor IUI. the frame of which is fixed to the outer ring member 2l and the rotor of which drives a gear III2, engaging with the gear Il. Thus by actuation of the controlling member I4, the motor IDI will introduce a predetermined angular displacement between the inner ring member 86 and the outer ring member 2i. This angular displacement will likewise be transmitted to the synchro 49 through the gear train Il, 53, 52.

A system incorporating the angle computer of Fig. 4 operates the same as does the system Fig. 1, except that the controlled object may be given a predetermined angle of elevation above the horizontal and maintained with its line of sight in said elevation. The angle of elevation is fed into the system by the controlling obiect $4 which will cause the outer ring member 2l to tilt with respect to the inner ring member e6 through the desired angle of elevation which, as previously described, is transmitted to the synchro I9. The synchro will then transmit the angle to the synchro 55 and its associated motor 53 (Fig. l) and thus cause the controlled object I to tilt about its tilt axis through the desired angle of elevation. Once the angle of elevation of the controlled object I is set in this way, the system thereafter operates to stabilize the position of the controlled object I in'exactly the same manner as described in connection with Figs. 1-3.

From the foregoing it will be seen that with the arrangement as shown in Fig. 4, the controlled object I may be set with its line of sight in a predetermined azimuthal angle at a predetermined elevation above the horizontal and such setting will be automatically maintained despite any motion of the ship.

Of course it is to be understood that this invention is not limited to the particular details as described above as many equivalents will suggest themselves to those skilled in the art. For example, although I have described the transmission of an angular position as occurring in each case between a single pair of synchros, other well known arrangements for increasing the speed and accuracy of such transmission may be utilized. One preferred arrangement is to use for each angular transmission a pair of transmitting synchros, one of which is geared to the angularly moving member by a gear ratio which multiplies the rotational speed. A similar geared pair of receiving synchros is associated with the transmitting synchros and a relay is utilized so that the high speed transmitting and receiving syn' chros are utilized for the major travel and the low speed transmitting and receiving synchros are utilized for the final fine adjustment. Since such a system is well known it has not been illustrated herein in the interest of simplicity and clarity. Also other types of angle transmitting systems may be utilized. Thus as used in the claims the term "synchro is intended to be understood in a generic sense to cover those devices which have a pair of relatively' rotatable members and which function to transmit or receive angular or rotational values. Various other equivalents which utilize the principles or the in- Y 9 vention enunciated herein will suggest themselves to those skilled in the art.

It is accordingly desired that the appended claims be given a broad interpretation commeni vsurate with the scope of the invention within the frame member, a ring member, and a reference member, said reference member having two relatively rotatable component parts, one of the component parts of said reference member being rotatable in said ring member about a ring axis xed withrespect to said ring member, the other component part f said reference member being rotatable about an axis substantially perpendicularto said ring axis, said ring member being rotatable in said frame member about a frame axis angularly disposed with respect to said ring axis and xed with respect to said frame member, control means having a reference member maintained in a predetermined reference plane, a linkage connecting said last-named reference member to said last-named component part and maintaining said axis of said last-named component part in fixed angular relation to said last-named reference member in a plane substantially -at right angles to said last-named reference member and passing through said last-named reference member and said last-named axis, said lastnamed component part `being fixed to said linkage to prevent rotation of said last-named component part with respect to said linkage about said last-named axis, and means for transmitting the angular changes between said component parts to said object.

2. In a position stabilizingsystem, an object whose position is to be stabilized, said object being movable about two axes angularly disposed relative to each other, a controlled gimbal system, said gimbai system comprising a frame member, a ring member, and a reference member, said reference member having two relatively rotatable component parts, one of the component parts of said reference member being rotatable in said ring member about a ring axis xed with respect to said ring member, the other component part of said reference member being rotatable about an axis substantially perpendicular to said ring axis, said ring member being rotatable in said frame member about a frame axis angularly clisposed With respect to said ring axis and xed with respect to said frame member, control means having a reference member maintained in a predetermined reference plane, a linkage connecting said last-named reference member to said lastnamed component part and maintaining said axis of said last-named component part in fixed angular relation to said last-named reference member in a plane substantially at right angles to said last-named reference member and passing through said last-named reference member and said lastnamed axis, said last-named component part being iixed to said linkage to Prevent rotation oi said last-named component part with respect to said linkage about said last-named axis, driving means responsive to the movement of the ring member of the controlled gimbal system relative to its frame member about its frame axis for moving said object about one of its axes through an angle substantially equal to the angle of motion between said controlled gimbal system ring and i'rame member, and driving means responsive to a change :in the angular relation between said componentparts for moving said object about its other axis through an angle substantially equal to said change in angular relation between said component parts.

3. In a position stabilizing system, an object whose position is to be stabilized, said object being movable about two axes angularly disposed relative to each other, a controlled gimbal sys,- tem, said gimbal system comprising a frame member, a ring member, and a reference member, said reference member comprising a synchro having two relatively rotatable component parts, said component.parts being electrically energized to produce an loutput signal which varies with variations in the angular relation between said component parts, one of the component parts of said reference member being rotatable in said ring member about a ring axis xed with respect to said ring member, the other component part of said synchro being rotatable about an axis substantially perpendicular to said ring axis, said ring member being rotatable in said frame member about a frame axis angularly disposed with respect to said ring axis and fixed with respect to said frame member, control means having a reference member maintained in a predetermined reference plane, a linkage connecting said lastnamed reference member to said last-named component part and maintaining said axis of said last-named component part in xed angular relation to said last-named reference member in `a plane vsubstantially at right angles to said lastnamed reference member and passing through said last-named reference member and said lastnamed axis, said last-named component part being ilxed to said linkage to prevent rotation of said last-named component part with respect to said linkage about said last-named axis, a second synchro having two relatively rotatable component parts o1' which one is fixed to said frame member and the other rotatable with said ring member, the component parts of said secondv synchro being likewise electrically energized to produce an output signal which varies with variations in the angular relation betwen said component parts, means responsive to one of said output signals to move said object about one of its axes in accordance with the variation in said output signal, and means responsive to the other oi.' said output signals to move said object about the other of its axes in accordance with the variation in said other output signal.

4. In a position stabilizing system adapted to be carried by a common carrying means, an obieet whose position is to be stabilized, said object being pivoted to an object frame along a predetermined axis, said object frame being rotatable on a supporting member about an axis angularly disposed relative to said predetermined axis, a controlled gimbal system, said gimbal system comprising a frame member and a ring member, said ring member beingrotatable in said frame member about a frame axis angularly disposed with respect to said ring axis and xed with respect to said frame member, a transmitting synchro which has two relatively rotatable component parts, said component parts being electrically energized to produce output signal currents which vary in accordance with changes in the angular relation between said component parts, a plurality vof receiving synchros, each of which has two relatively rotatable component parts, one of said component parts being supplied with signal currents to establish a predeter- 11 mined position of said component parts, the other of said component parts producing a signal in accordance with the angular deviation of said last-named component parts from said predetermined position, one of said receiving synchros having one of its component parts rotatable in said ring member about a ring axis iixed with respect to said ring member, means for maintaining the axis, about which the other component part of said last-named synchro is rotatable, fixed in a predetermined direction with variations in the position of said carrying means, means responsive to the output signal of said lastnamed synchro for driving said frame member to a position of angular agreement between the component parts of said last-named synchro, said transmitting synchro having one of its component parts nxed with respect to said carrying means, and the other of its component parts rotatable with said frame member, another of said receiving synchros having one of its component parts xed with respect to said supporting member, and the other oi' its component parts being rotatable with said object frame, the output signal currents of said transmitting synchro being supplied to said last-named receiving synchro,

means responsive to the output signal of said last-named synchro for driving said object trame to a position of angular agreement between the component parts of said last-named synchro, and means for supplying position predetermining signal currents to said nrst-named receiving synchro to predetermine the positionof said object.

5. In a position stabilizing system adapted to be carried by a common carrying means, an object whose position is to be stabilized, said object being pivoted to an object frame along a predetermined axis, said object trame being rotatable on a supporting member about an axis angularly disposed relative to said predetermined axis, a controlled gimbal system, said gimbal system comprising a frame member and a ring member, said ring member being rotatable in said frame member about a frame axis angularly disposed with respect to said ring axis and nxed with respect to said frame member, a plurality of transmitting synchros, each of which has two re1- atively rotatable component parts, said component parts being electrically energized to produce output signal currents which vary in accordance with changes in the angular relation between said component parts, a plurality of receiving synchros, each of which has two relatively rotatable component parts, one of said component parts being supplied with signal currents to establish a predetermined position of said component parts, the other o! said component parts producing a signal in accordance with the angular deviation or said last-named component parts from said predetermined position, one of said receiving synchros having one of its component parts rotatable in said ring member about a ring axis nxed with respect to said ring member, means for maintaining the axis, about which the other component part of said last-named synchro is rotatable, iixed in a predetermined direction with variations in the position of said carrying means, means responsive to the output signal of said last-named synchro for driving said frame member to a position of angular agreement between the component parts of said last-named synchro, one of said transmitting synchros having one of its component parts xed with respect to .said carrying means, and the other of its component parts rotatable with said trame member, another of said receiving synchros having one of its oomponent parts fixed with respect to said supporting member, and the other o! its component parts being rotatable with said object frame, the output signal currents of said transmitting synchro being supplied to said last-named receiving synchro, means responsive to the output signal of said last-named synchro for driving said object frame to a position oi' angular agreement between the component parts of said last-named synchro, another of said transmitting synchros having one of its component parts iixed with respect to said frame member, and the other of its component parts rotatable with said ring member, another of said receiving synchros having one of its component parts iixed with respect to said obiect frame and the other of its component' parts rotatable with the rotation of said object about said predetermined axis, the output signal currents or said last-named transmitting synchro being supplied to said last-named receiving synchro, means responsive to the output signal of said last-named synchro for driving said object to a position oi' angular agreement between the component parts of said last-named synchro, and means for supplying position predetermining signal currents to said mst-named receiving synchro to predeterf mine the position of said object.

8. In a position stabilizing system adapted to be carried by a common carrying means, a controlled gimbal system, said gimbal system comprising a reference member, a main ring member, an auxiliary ring member and a frame member, said reference member being rotatable in said main ring member about a main ring axis ilxed with respect to said main ring member. said main ring member being rotatable in said auxiliary ring member about an auxiliary ring axis angularly disposed with respect to said main ring axis and ilxed with respect to said auxiliary ring member, said auxiliary ring member being rotatable in said frame member about a frame axis parallel tovsaid auxiliary ring axis and fixed with respect to said frame member, means for setting said auxiliary ring member in a predetermined angular relationship with respect to said main ring member, said gimbal system having a reference axis formed by the intersection of two planes lying respectively along said main ring and frame axes and fixed respectively with respect to said main ring and trame members, and means for maintaining said reference axis in a predetermined direction with variations in the position of said carrying means.

7. In a position stabilizing system adapted to be carried by a common carrying means, an object whose position is to be stabilized, said object being movable about two axes angular-ly disposed relative to each other, a controlled gimbal system, said gimbal system comprising a reference member, a main ring member, an auxiliary ring member and a frame member. said reference member being rotatable in said main ring member about a main ring axis fixed with respect to said main ring member, said main ring member being rotatable in said auxiliary ring member about an auxiliary ring axis angularly disposed with respect to said main ring axis and fixed with respect to said auxiliary ring member, said auxiliary ring member being rotatable in said frame member about a frame axis parallel to said auxiliary ring axis and xed with respect to said frame member, means for setting said auxiliary ring member in a predetermined angular relationship with respect to said main ring member,

said gimbal system having a reference axis formed by the intersection of two planes lying respectively along said main ring and frame axes and nxed respectively with respect to said main ring and frame members, means for maintaining said reference axis in a predetermined direction with variations in the position of said carrying means. and driving means responsive. to the movement of said auxiliary ring member relative to the frame member about the frame axis for moving said object `about one of its axes through an angle substantially equal to the angle of motion between said auxiliary ring member and said frame member.

8. In a position stabilizing system adapted to be carried by a common carrying means, anobject whose position is to be'stabilized, said object being movable about two axes angularly disposed relative to each other, a, .controlled gimbal system, said gimbal system comprising a reference member, a main ring member, an auxiliary ring member and a frame member, said reference member being rotatable in said main ring member about a main ring axis fixed with respect to said main ring member, said main ring member being rotatable in said auxiliary ring member about an auxiliary ring axis angular-ly disposed with respect to said main ring axis and fixed with respect to said auxiliary ring member, said auxiliary ring member being rotatable in said frame member about a frame axis parallel to said auxiliary ring axis and fixed with respect to said frame member, means for setting said auxiliary ring member in a predetermined angular relationship with respect to said main ring member, said gimbal system having a reference axis formed by the intersection of two planes lying respectively along said main ring and frame axes and fixed respectively with respect to said main ring and frame members, means for maintaining Y spect to said frame member, means for setting said which has tworelatively rotatable componentV parts, one of said component parts being supplied with signal currents to establish a predetermined position with respect to said component parts, the other of said component parts producing a signal. in accordance with the angular deviation of said last-named component parts from said predetermined position, one of said receiving synchros having one. of its component parts rotatable in said main ring member about a main ring axis nxed with respect to said main ring member, means for maintaining the axis about which the other componentpart of said last-named synchro is rotatable, fixed in a predetermined direction with variations in the position of said carrying means, means responsive to the output signal of said last-named synchro for driving said frame member to a position of angular agreement between the component parts of said last-named synchro, one of said transmitting synchros having one of its component parts xed with respect to said carrying means, and the other of its component parts rotatable with said frame member, another of said receiving synchros having one of its component parts fixed with respect to said supportsaid reference axis in a predetermined direction with variations in the position of said carrying means, driving means responsive to the movement of said auxiliary ring member relative to the frame member about the frame axis for moving said object about one of its axes through an angle substantially equal to the angle of motion between said auxiliary ring member and said frame member, and driving means responsive to a change in the angular position of the projection of said main ring axis upon a plane substantially at right angles to the reference axis for moving said object about the other of its axes through an angle which is equal to the change in the angular position of said projection. e

9. In a position stabiliing system adapted to be carried by a common carrying means, an object whose position is to be stabilized, said object being pivoted to an object frame along a predetermined axis, said object frame being rotatable on a supporting member about an azimuth axis angularly disposed relative to said predetermined axis, a controlled gimbal system, said gimbal system comprising a reference member, a main ring member, an auxiliary ringv member and a frame member, said reference member being rotatable in said main ring member about a main ring axis xed with respect to said main ring member, said main ring member being rotatable in said auxiliary ring member about an auxiliary ring axis angularly disposed with respect to said main ring axis and fixed with respect to said auxiliary ring member, said auxiliary ring member being rotatable in said frame member about a frame axis parallel to said auxiliary ring axis and fixed with reing member, and the otherof its component parts being rotatable with said object frame, the output signal currents of said transmitting synchro being supplied to said last-named receiving synchro, means responsive to the output signal of said last-named synchro for driving said object frame to a position of angular agreement between the component parts of said last-named synchro, another of said transmitting synchros having one of its component parts xed withrespect to said frame member, and the other of its component parts rotatable with said auxiliary ring member, another of said receiving synchros having one of its component parts fixed with respect to said object frame and the other of its component parts rotatable with the rotation of said object about said predetermined axis, the output signal currents of said last-named transmitting synchro being supplied to said last-named receiving synchro, and means responsive to the output signal of said last-named synchro for driving said object to a position -of angular agreement between the component parts of said lastnamed synchro.

10. An angle computer comprising a gim-bal system, said gimbal system comprising a frame member and a ring member, a receiving synchro,

which has two relatively rotatable component4 means, means responsive to the output signal -ot said last-named synchro for driving said frame member to a position of angular agreement between the component parts of said last-named synchro, a plurality of transmitting synchros, each of which has two relatively rotatable component parts, said component parts being electrically energized to produce output signal currents which vary in accordance with changes in the angular relation between said component parts, one of said transmitting synchros having one of its component parts ilxed with respect to said carrying means, and th'e other of its component parts rotatable with said frame member, another of said transmitting synchros having one of its component parts ilxed with respect to said frame member, and the other o! its component parts rotatable with said ring member.

11. An angle computer comprising a gimbal system, said gimbal system comprising a reference member, a main ring member, an auxiliary ring member and a frame member, said reference member being rotatable in said main ring member about a main ring axis ilxed with respect to said main ring member, said main ring member being rotatable in said auxiliary ring member about an auxiliary ring axis angularly disposed with respect to said main ring axis and fixed with respect to said auxiliary ring member, said auxiliary ring member being rotatable in said frame member about a frame axis parallel to said auxiliary ring axis and iixed with respect to said frame member, means for setting said auxiliary ring member in a. predetermined angular relationship with respect to said main ring member, and means for attaching said reference member to a position stabilizing means.

12. An angle computer comprising a gimbal system, said gimbal system comprising a main ring member, an auxiliary ring member and a frame member, said main ring member being rotatable in said auxiliary ring member about an auxiliary ring axis angularly disposed with respect to said main ring axis and fixed with respect to said auxiliary ring member, said auxiliary ring member being rotatable in said frame member about a frame axis parallel to said auxiliary ring axis and fixed with respect to said frame member, means for setting said auxiliary ring member in a predetermined angular relationship with respect to said main ring member, a plurality of transmitting synchros, each of which has two relatively rotatable component parts, said component parts being electrically energized to produce output signal currents which vary in accordance with changes in the angular relation between said component parts, a receiving synchro which has two relatively rotatable component parts, one of said component parts being supplied with signal currents to establish a predetermined position with respect to said component parts, the other of said component parts producing a signal in accordance with the angular deviation of said last-named component parts from said predetermined position, said receiving synchro having one oi its component parts rotatable in said main ring member about a main ring axis fixed with respect to said main ring'member, means for attaching the other of said component parts to a position stabilizing means, means responsive to the output signal of said last-named synchro for driving said frame member to a position of angular agreement between the component parts of said last-named synchro, one o! said transmitting synchros having one oi its components parts iixed with respect to said carrying means, and the other oi' its component parts rotatable with said frame member. another oi said transmitting synchros having one oi' its component parts fixed with respect to said trame member, and the other ot its component parts rotatable with said auxiliary ring member.

13. In a position stabilizing system. two gimbal systems, each comprising a irame member, a ring member, and a reference member, said reference member being rotatable in said ring member about a ring axis fixed with respect to said ring member, said ring member being rotatable in said frame member about a frame axis angularly disposed with respect to said ring axis and iixed with respect to said frame member, the reference member of one ot said gimbal systems carrying two parallel arms spaced from each other, the reference member of the other oi said ixnbal systems carrying a single arm of the same length as said parallel arms, a triangular member rotatably connected at its spices to each of said three arms for holding said reference members in predetermined orientation with respect to each other.

14. In a position stabilizing system, a reference position determining device. a gimbal system, a common support for said position determining device and said gimbal system, and a signal generator including relatively rotatable, coaxial stator and rotor members, one of said members being supported in said gimbal system, and the other being linked to said position determining device and, by said link, tlxed against rotation with respect to said device,whereby tilting oi said support, in a plane other lthan mutually perpendicular planes which include the pivots o! said gimbai system and the axes of said stator and rotor members, results in relative rotation between said stator and rotor members and the generation oi a position correcting signal.

JOHN W. DAWSON.

REFERENCES CITED The following references are of record in the tile of this patent:

UNITED STATES PATENTS 1,840,104 Anschutz-Koempfe Jan. 5, 1932