US2531188A - Automatic pitch control - Google Patents

Description

An object o1: tl-ie invention is to provide contoinatieally maintains substantially constant altitude during turns Y Another object or the invention is to provide an automatic pilot having s. circuit for anton-iatcounteracting loss of vertical lift or an aircraft during a banls and which circuit need not be located at tl-ie control station of tlfie automatic pilot.

,According to my invention. I provide an automatic pilot systern having cial correction mechanism responsive which counteracts the loss of lift during curved rligl-i This signal is generated irrespective of the direction o a an -varies as function or the ans-le of barils.

xnent necessary for providing tl-iis counteractinesignal need not be located at the pilot's e ceoxnpanying schematic drawing of an autoniatic pilot system embodying Vi-ny invention.

Referring to the d rawin control surfaces 2 and s represent the conventional aileron and elevator used for controlling the movements or an aricraft abou tne anis and pitch. axes respectively.

Dlsplacements or the aircraft about the lateral or pi axis and the longitudinal or bank axis a suitable positionas a onventiona er- 4 l-i arnpliller and motor 5 used to operate the aileron ma any suitable type and its operation is well known in the art. one such. suitable servo ampliner and motor is de a direction oeterrnined by trie polarity oi tbe input signal voltage and at a speed xvhi is i n limits, n magnitude or a le servo arnplier and mo or responsive to position-maintaining means (not show he operation of tlie rudde c n weve i we l than electric-hydraulic. motors. may be used to accomplish tbe same re*` sult.

The signal system in response o which tl-ie ed to actuate the ailerons ne aircraft so as to maintain well as straight aircraft about pitch and bank axes which stabilized in space. prises a rotating gyro elenient ls l-iavirier a vertical spin axis, the gyro be ine rotated by any suitable motor inea the ax` o rotation f lies in the directie l-ie longitudinal axis while the axis or rotation or the sini-bal l s lies in the aircraft about tl-ie axes measured by tlie movement of the relative to the ein-bals ls and zo in a well known manner T obtain control voltages variable in magnitude and polarity in, accordance with trie ydisairn-art aoont tne axis n n vi-nie the rotor oi the nxed signal generator 2z is directie coupled so or to the right is necessary since loss of :Lift oetl-ie gozaba; y:s of the vertical erro so it will nsive respo t e displacement o1: the aircraft about the pitch aids Balea the direction of b e aileron z vand the elevator 3 are Ycontrolled The eil-cuit, 21 would preferably be located ra Vby voltages introduced in aileron and elevator 35 inoteiy from the control station in order to :reen signal circuits 1 a a. d s, H3 respectively at nai iniurn th am nt of e inpment which ne connected respectively to the input terminal is located in the coclrpit. el-erably, th oirof the ail on i nd elevato servo amplifierscuit 21 should be near the autopilot amplifier In the aileron and elevator signal circuita there where signal uniting is carried out. Yare connected the stator windings of the rol- 4o isolating translow-un sn as. Veeneintors 23 an 24 which e ding 30 whose s identite l construction to the barils cted in eracleaand pitch siena-1 generators 2a and zz nreviousw on. signal circuit at a point across the banle co describe The rotors of the follow-u signal w ll hereinafter generators ar mechanically coupled to the ou g5 co i two nut shaft of the servoni as indicated by the the ripper one of which may dotted lines 5 2s, so that they are rotated in. and a cenitne dir ction fr ai t n o aero vol e pon sition in accordance with the direction or niovewhich also have meaat of the servoinotor fr m ositiori coia-Y- 5o f the secon indto the nicht neutral or st ed noarc connected two excistion of th associated control surrace e tation crarnforiners 3s, au respectivelyin -c the ry win i e follow-up of nicltation the transformer 3s. is :ui-nit the movement of the associated con- 4a may be replaced by one transform having trol sui-falce to an amount proportional to a d isa in y winding and two secondary p acernent signal voltage introduced elsewhere in finding of transformthe signa. circuit in a manner whi l subses() al. 42 and ceritn iei-itlsr e described. This is accomplnhed by winding or connectin the stator windings or the follow-u. er au .is identified by term-hals 44. 4S and signal generator with its respective signal circuit a or ansso Y oduce a voltage opposing the d` l pper circuit cornrnent voltage respons t movement o the 1 istor 4s and. zar-v o rs and the controlled surfaces initiated f A siinilar circuit is n nected to hy applicatio of th cexne t signal voltage. as which compr-nes i-11e pronortionine action ol' follow-up s' resistor 53v and. rectifier genera oves the stability of t control Junction of resistors 4a, s and and. prevents hunting of the control snriaees and e pper seconda w aircraft` In addition. the follow-up i Y serii 'o of transfornier 2s thn-e is connected a rectifier erator es the control surface to be returned r rectifier 5S is connected between nig t nent-ral n the absence of displacement Junction and. the opposite terminV 34 voltage e where in he signal circxii 1n. order to operate the aileron 2 in a manner to stabilize the aircraft about the lon 'tudinal or ila:- circuitsV to the lower secondary winding of upper half of circuit 21. Also the rectiners 51 and 42 are negative, Because of the potential r :9.

across the secondary vvindiiiaY or transforme 3U transformer 2 is at resistor d.. c a negative :x5 of resistor 5s c a sfne avc.

oportional to the ,in udc. this means put voltage appearing across resistor 5s is then r signal circuit so as to signal which will correct output resistor 5a. Because of the oppositely dis- 5o .e turns posed rectiier 5s substantially no current will l 1: to manually ernow in the circuit coniaected across the secondary winding between terminals 34 and time mid-tap barns control 2s 3 o Displacement Having now examined the foregoing circuit 5r; eetl-ier causes when the polarities of transformers 2s d 3a i e onl of transforme as are reversed The instantaneous polarities at terminal 33 and at n on depending: u he termina 3a will remain u changed, ut novJ, the 1: c since the aircraft instantaneous polarity at terminal al will now be to reduce assumed to be negative while that at terminal 42 nt vo1tage fed inwill he assumed to be positive. Due to the relatively high impedances of the oppositely df'sposccl 'S5 pit-S11 or the aircraft rcctiflers 41 and 5u. substantialy no cui-rent will during turn. i manipu..

now now in the chopper circuits which can be resistors as t ff becomes displaced about the barils or pitch axes and. the junction of resistors a8, 4e. This high 1f 1x; .is desired no maxe s. .Lexis c the cans control knob So is d'splseed te the left and :rust

the elevator in. a. nose-up no oxmteraet for the less of v 'e e me left bas-.xs 11; may be round that some relationship between e aileron sie-ns1 verf-age and the voltage -cc one o1 d 1c counters. c' tel-:e its pu fr o an crease 1h he vermamr suitable point in the bank sns-neel ce1 lift. or said aircraft: wluile banking. wise. the out-pun of c' cuit 1 may be introduced CHARLES G. YATES. Ja. at c pois:` s ih the pitch channel. it b ehi; that the coun Y lane Maheuvenhg System REFERENCES C11-,CED

The following rerermces are of record in `alle me c1.' his -paxentz UNITED STAFE.. S PAM :LS

u mher 2,452,311 2,471.321 2,516.79

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