US2938154A

US2938154A - Forbidden rotation reversing, position control servosystem

Info

Publication number: US2938154A
Application number: US675507A
Authority: US
Inventors: Herbert S Kirschbaum
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-07-31
Filing date: 1957-07-31
Publication date: 1960-05-24
Anticipated expiration: 1977-05-24

Description

May 24, 1960 H. s. KlRscHBAuM 2,933,154

FORBIDDEN RoTATIoN REvERsING, POSITION CONTROL sERvosYsTEM Filed July :51, 1957 FIG. 2

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a lll D v l t HERBERT s. KlRscHBAuM w INVENTOR.

v 1 asiawounalod Noulsod une BY FORBIDDEN ROTATION REVERSING, POSITION CONTROL SERVOSYSTEM Herbert S. Kirschbaum, Columbus, Ohio, assgnor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed July 31, 1951, ser. No. 675,507

a claims. (ci. V51e- 29) The present invention relates to an automatic synchronizer for controlling the'training of a gun mechanism and more particularly to an automatic stop avoiding synchronizing circuit.

In the prior art, there are numerous types of automatic synchronizers available to synchronize the training position of a gun with the position indicated at some remote control station. In these prior systems, the gun rotates or trains through the shortest path to synchronize with the indicated position of the control station unless otherwise prevented by a stop or limit which is between the actual gun position and its ultimate desired position designated by the control station. However, if the gun can not synchronize because a stop or limit intervenes, the prior art systems must be deenergized and the gun rotated manually to a position such that the automatic synchronization can take place unhindered.

The present invention is a system of connecting a gun position potentiometer and a stop position potentiometer so that the above mentioned disadvantages are overcome and that the gun is always synchronized with a control station.

An object of the present invention is the provision of a system that automatically synchronizes a gun with a control station through the shortest path of training of the gun regardless of the initial position of the gun relative to the position requested by the control station unless the shortest path is barred by a limit stop.

Another object of the present invention is the provision of automatically synchronizing a gun to the control station through the longer path of training if the shortest path of training of a gun is barred by a limit stop.

A further object of the invention is to provide synchronization of the gun with limit stops set as far apart as 720 (Lt-360).

A further object of the invention is the provision of synchronizing a gun of minimum training angle when the control station is indicating a position within the allowable gun training range.

A still further object of the invention is to provide synchronization of the gun within the dead zone of the control station potentiometer.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

Fig. 1 is a schematic diagram of a suitable form of the automatic synchronizer circuit.

Fig. 2 is a diagram showing the details of the control station potentiometer.

In Fig. l, the stop avoiding synchronizing circuit is shown as having three

potentiometers

61, 11, and 21, and three relays R3, R4 and R5.

The potentiometers are connected in parallel between e, positive and a negativek voltage source. The gun po- 2,93,l54 Patented May 24, 1960 sition potentiometer 61 with its slider '62 is geared to the gun in such a manner that the slider 62 traverses the entire potentiometer when the gun rotates a total of two revolutions, (i360).

The second potentiometer referred to as the stop position potentiometer 11, has two movable sliders 12 and 13. The sliders 12 and 13 are set to coincide with the automatic cut-ott position beyond which the gun can not train except manually.

A desired gun training position is determined at the control station. This new training position is indicated in the synchronizing circuit by the third potentiometer, that is the control station potentiometer 21, in conjunction with a split pick-up strip 26. The split pick-up strip 26 is made up of two parts, the clockwise section 27 and the counterclockwise section 28. The control station potentiometer 21 has two sliders 24 and'25 spaced 180 apart. The

sliders

24 and 25 as shown in Figs. ll

and 2 make contact between the control station potenti-l ometer 21 and the split pick-up strip 26 in such a manner that each slider contacts only one section of the strip at any instant. The

sliders

24 and 25 can rotate continuously and provide electrical contact over as much of the 360 of the control station potentiometer 21 as possible and are driven from the control station by means of a synchromotor and suitable gearing to give exactly one control station potentiometer revolution for two control station revolutions. However, the

sliders

24 and 25 must not short the sections 27 and 28 together.

Relays R3, R4, and R5 with their contacts connect the three potentiometerstogether. Relays R3 andR4 are made polarity sensitive by

rectiiiers

14 and 15, respectively. Relay R3 has two contacts; R31 normally closed and R32 normally opened. Relay R4 has two contacts; R41 normally closed and R42 normally opened. Relay R5 has four contacts; R51 normally closed, R52, R53 and R51-tl normally opened. Due to the action of either

rectifier

14 or 15, one of the relays R3 and R4 operate when the position of either slider 24 or 25vindicates a potential difference over the potential at one of the sliders 12 and 13. This potential difference between potentiometer 21 and potentiometer 11 through one of the pick-up strips causes one of the relays to operate thereby connecting a potential from the other pickup strip to the right side of relay R5. The other side of relay R5 has a potential of a value dependent upon the position of slider 62 of the gun position potentiometer. When the potential across relay R5, determined by the dilerence between the potential of the other pick-up strip and that indicated by the slider 62, is great enough; the

. relay R5 will be energized causing the relay contacts of R5 to operate, cutting out demodulator 70, and thereby applying this same potential across relay R5 and its associated polarity to the D C. amplifier 75.

There are three possible desired gun train positions as called for by the control station which might arise in the course of synchronizing a gun as noted by the A, B and C positions of

sliders

24 and 25.

in position A both

sliders

24 and 25 lie within the region between the stop position sliders 12 yand 13 on the stop position potentiometer as shown in Fig. 1. The potential on the control station potentiometer 21 at position A of slider 24 is less negative than the potential on stop position potentiometer 11 at slider 13 so that relay R4 does not operate due to the inaction of rectier 15. In the same manner, the potential on the control station potentiometer 21 at slider 25 position A is less positive than the potential on the stop position potentiometer 11 at slider 12 and consequently relay R3 does not operate due to the inaction of rectifier 14. In this position A, it will be apparent that no potential is applied to relayA R5`and that the gun synchronizes normally through the action of the error-measuring synchros, the demodulator 70, the amplier 75, generator 78 and motor 80 to drive the gunto the new position.

At position Bone of the sliders of the control station potentiometer 21 is beyond the lcounterclockwise stopV position of slider 12 of the stop position potentiometer 11. In this position B, the shortest physical path for the lgun to synchronize would be a counterclockwise one, providedV there is no automatic cut-oifs or limit stops betweenthe gun and control station.Y However, it is seen from'Fig. 1 that if thel gun continues to move in the counterclockwise direction it would runv into they automatic cut-off before vreaching the desired position.

The circuit ofthe invention as shown in Fig, l operates at position Bas follows. Relay R4 remains deenergized duetothe' inaction ofthe rectifier 15,but relay R3 is now" energizedl since the potential difference between point 7 on the pick-up section 28 and slider 12 has a value which allows current to flow` through the rectifier 14. This is now possible since contact 25 at position B on control station potentiometer 21 indicatesa greater potential than the potential at. slider12 on stop position potentiometer 11'. Upon the energization of relay R3, contact R31 is opened and R32 is closed. Upon lthe closing of contact R32, the negative potential from point 8 on the=clockwise section 27l isapplied. through,l contact R32-and` closed contact .R41 torelay R5. Since the gun isVI still at theprevious position, the gun position potentiometer indicates'. a certain potential atv slider 62. The potential. differencebetween, slider 62 and section 27 causes current to ow through relay R5 operating the relay R5. contacts.A These contacts `disconnect the vdemodulator 70from the amplier 75 and connect to the amplifier this same potential difference which is proportional to the angle between the gun and slider on the clockwise section 27 on the control station potentiometer. This potential differencewhich is applied to the ampli-r lier and subsequently tothe generator and motor, is of such polarity as to cause the gun to move inthe clockwise direction. As the gun moves in the clockwise direction, the potential at slider 62 approaches the potential of slider 24 at position B, whereby the potential across relay R5 decreases until relay R5 finally is deenergized. At this time, the gun is in position near enough to the new desired position as indicated bycontrol station potentiometer y,21 that normal synchronization can take place.

At position C, one of thefsliders of the control station potentiometer'is in position on. thev clockwise section 27 beyond theclockwise-stop position of slider 13 on the stop.position'potentiometer 11. The operation in position C of the preferred embodiment of the invention as shown in Fig. 1 isas follows. Relay R4 is now energized since the potential at point 8 isr greater than the potential at slider 13 on the stop position potentiometer 11, that is, greater in a negative sense so that a current can now flow through rectifier 15. Relay R3 is deenergized since rectifier 14 does. not allow any cur- Y rent to pass through it. VUpon .the operation of relay R4, contact R41 opens and contact R42 closes thereby applying a potential from point 7 through contact R42 and through contact R31 to relay R5. A potential difference which is proportional to the angle between the gun as notedby the position of slider 62 on gun position potentiometer andi the slider on the counterclockwise section 28 on the control station potentiometer operates relay R5 hereby disconnecting the demodulator 70 from therl amplifier 75 and feeds this potential difference to the amplifier.

This potentialA diierence is of suchk polarity that the gun; moves in the clockwise direction. vAsthe gun so moves, the potential across relay R5 decreases until relay R51 nally drops out.` Atvthistime, the gun is near enough to the desired control station position that it will synchronize normally.-

A similar sequence of operations will also take place if the gun position slider indicates a position on the clockwise portion of the potentiometer 61. In this case, the circuit operates as before to detect the presence of the stop in the synchronizing path of the gun and provides the signal to the amplilierto move the gun in a direction to avoid the stop.

Under certain gun empla'cement conditions, the training range of agun may have'l the requirement that the minimum angle `between the automatic` cut-offs. be only A and consequently more than two-thirds of the full 360 of train is forbidden to the gun.. Thelimited positions are indicated by D inFig. 1. In this case if the sliders 24 and 25' are in position A, then each slider of the control station potentiometer is beyond the allowable region of operation of the gun. Both relays R3 and R4 are energized and therefor no potential is applied across relay R5. The gun during normal synchronizing is stopped by one of the automatic cutols. Synchronization can take place only if one of the slidersv on ,the control station potentiometer is brought within the allowable gun position training rangeas would Ibe the case at' position B or C ofthe-sliders of the controlv station potentiometer. y

In order to avoid a 2 to 3- dead zone between the ends ofy the control-station potentiometer and the 'ends of the pick-up sections, a--cam-operated vswitch R6 is connected-between-.relayfRS andthe ycenter'rtap of the control i station 'potentiometer-1 y,at` point 9.v When the

sliders

24 and 25 arefwithin the-dead zoneneither relay R3 nor relay R4' isl energized'. By the-incorporation ofk theswitch Rlwhich closes when the sliders arerin the dead zone,.a potential willbe applied across relay R5.'

One modification of. the. embodiment of the invention shown inrFig.,1V would be. to have cam-operated toggle switchesk actuated by the shaft of the ycontrol station potentiometer instead ofthe illustratedv split' pick-up strip. An. additional modification would be ,toV replacethe relays R3 and R4 and theirassociated rectiiiers 14V and: 15l`by polarized relays. Y

Obviously many modifications and variations; of the present invention are-possible in the light of the above teachings. It is Vtherefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A stop avoiding synchronizing circuit having first means VVfor indicating av potential` representative of,r the actual gun position, secondk means for indicating'a potential representative ofL the: automatic'cutf-oiv position of a gun beyond which the gun cannot train,'third means for4 indicating a new vposition that thegunA automatically trains to, a first relay mechanism, a second relay mechanism, saidsecond means connected to saidA thirdrmeans through said rstrelay mechanism,l `said third means connected to saidfirst means through. said first and second relay mechanism, saidV third meanshaving indicating means for indicating a first potential on4 said third means greater than the potential on said second means whereby saidy first relay mechanism is energizedand a second potential from said third means is connected' to said second relay mechanism thereby causing said second relay mechanism to operaterand to establish a potential difference between said first means and said third means proportional to the angle betweenrthergunv andthe indicating means of said third means to control the training of the gun in a directionaway from the automatic cut-off position. Y Y

2. A stop avoiding gun training synchronizing circuit comprising first means for establishing a potential representative of the actual gun training position, second means for establishing potentials representative of the automatic cut-off positions of the gun, third means for establishing potentials representative of a ldesired gun training position designated by a control station, said third'means including aV splitpickup strip anda posunmhllr tentiometer with two sliders placed 180 apart, said split pick-up strip comprising a clockwise section and a counterclockwise section, each of said sliders making contact between said potentiometer and one of said sections of said split pick-up strip, a pair of polarized operating means, each of said sections connected to said second means through one of said polarized operating means, said second means and one of said sliders of said potentiometer determining through one of said sections the operation of one of said polarized operating means, make and break means, switch means, make and break means connected between said sections and said switch means, said switch means connected between said first means and said make and break means, said one of said polarized operating means establishing an electrical connection through said make and break means from the other of said sections to said switch means and said first means whereby the first and third means determine a potential dilerence and its polarity proportional to the angular difference between the actual gun training position and the desired gun training position and operates said switch means thereby applying said potential difference to drive the gun to the desired position in a training direction away from the automatic cut-off position.

3. A system for automatically synchronizing a gun in training position with a desired position indicated at a control station comprising a voltage source, a gun position potentiometer, a control station potentiometer, and a stop position potentiometer connected in parallel across said voltage source, said gun position potentiometer having a slider indicating a potential representing the position of the gun, a split pick-up strip associated with said control station potentiometer, said control station potentiometer having two sliders placed 180 apart which ride on said split pick-up strip, said stop position potentiometer having sliders set to coincide with the automatic cut-o6 position beyond which the gun cannot train, a pair of relays, a third relay, said stop position potentiometer connected from its sliders through said pair of relays and said split pick-up strip to said control station potentiometer and through the contacts of said pair of relays to said third relay to said gun position potentiometer, said third relay connected between the slider of said gun position potentiometer and the contacts of said pair of relays, a generator, a motor, an amplifier, a demodulator coupled to said amplifier supplying current to the field coil of said generator, said motor for training the gun connected to the output of said generator, contacts of said third relay connected between said third relay, said demodulator, and said amplifier, whereby one of the pair of relays operates to connect across the third relay a potential difference proportional to the angle between the gun potentiometer slider and the other slider of said control station potentiometer in response to one of the sliders of the control station potentiometer indicating a desired position beyond the automatic cut-off position as indicated by one of the sliders of the stop position potentiometer to cause the relay contacts of the third relay to disconnect the demodulator from said amplifier and to substitute therein said potential difference to move the gun in a direction to the desired position thereby avoiding the automatic cut-of position.

References Cited in the tile of this patent UNITED STATES PATENTS 2,583,058 Libman Jan. 22, 1952 2,750,553 Anderson June 12, 1956 2,767,361 Bloomquist et al. Oct. 16, 1956