swh:1:snp:92f3f585b9ae79620ad8c41a332d6329b31fd381
Tip revision: 078c79d8734a9ed2860303a7c1662004284fe853 authored by Ron Burkey on 07 August 2022, 15:04:04 UTC
Fixed a potential string-overflow bug in yaASM. Removed timestamps from
Fixed a potential string-overflow bug in yaASM. Removed timestamps from
Tip revision: 078c79d
TRIM_GIMBAL_CONTROL_SYSTEM.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: TRIM_GIMBAL_CNTROL_SYSTEM.agc
## Purpose: A module for revision 0 of BURST120 (Sunburst). It
## is part of the source code for the Lunar Module's
## (LM) Apollo Guidance Computer (AGC) for Apollo 5.
## Assembler: yaYUL
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 2016-09-30 RSB Created draft version.
## 2016-10-18 MAS Began.
## 2016-10-19 MAS Completed transcription.
## 2016-10-31 RSB Typos
## 2016-12-06 RSB Comment-proofing with octopus/ProoferComments,
## changes made.
## Page 591
BANK 21
EBANK= DT
# CONTROL REACHES THIS POINT UNDER EITHER OF THE FOLLOWING TWO CONDITIONS ONCE THE DESCENT ENGINE AND THE DIGITAL
# AUTOPILOT ARE BOTH ON:
# A) THE TRIM GIMBAL CONTROL LAW WAS ON DURING THE PREVIOUS Q,R-AXIS TIME5 INTERRUPT (OR THE DAPIDLER
# INITIALIZATION WAS SET FOR TRIM GIMBAL CONTROL AND THIS IS THE FIRST PASS), OR
# B) THE Q,R-AXES RCS JET CONTROL LAW ATTITUDE STEERING MODE REDUCED THE ATTITUDE ERROR TO LESS THAN
# 1DEGREE ON EACH AXIS ON ITS LAST TIME5 INTERRUPT.
# THE FOLLOWING T5RUPT ENTRY BEGINS THE TRIM GIMBAL CONTROL LAW. SINCE IT IS ASSUMED THAT THE LEM WILL REMAIN
# UNDER TRIM GIMBAL CONTROL, A KALMAN FILTER RUPT IS SET UP TO BEGIN 30 MS FROM THE TRIM GIMBAL RUPT.
GTS CAF MS30F # RESET TIMER IMMEDIATELY: DT = 30 MS
TS TIME5
LXCH BANKRUPT # INTERRUPT LEAD IN (CONTINUED)
EXTEND
QXCH QRUPT
EXTEND
DCA POSTPFIL
DXCH T5ADR
TCF GTSTEST # SKIP OVER XFORMS UNTIL REORGANIZATION
GIMBAL EXTEND # GET D.P. FILTERED CDUY VALUE (ONES COMP)
DCA CDUYFIL # SCALED AT 2PI RADIANS
TC ONETOTWO # FORM S.P. VALUE IN TWOS COMPLEMENT AT PI
EXTEND
MSU CDUYD # FORM Y-AXIS ERROR IN ONES COMPLEMENT
TS QDIFF # (SAVE IN Q-AXIS ERROR LOC: EFFICIENCY)
EXTEND # GET D.P. FILTERED CDUZ VALUE (ONES COMP)
DCA CDUZFIL # SCALED AT 2PI RADIANS
TC ONETOTWO # FORM S.P. VALUE IN TWOS COMPLEMENT AT PI
EXTEND
MSU CDUZD # FORM Z-AXIS ERROR IN ONES COMPLEMENT
TS RDIFF # (SAVE IN R-AXIS ERROR LOC: EFFICIENCY)
# TRANSFORM Y,Z CDU ERRORS TO THE Q,R-AXES.
EXTEND # GET BOTH Y AND Z CDU ERRORS AT PI RAD
DCA QDIFF
TC QTRANSF # FORM Q-ERROR IN A (SCALED AT PI RAD)
DXCH QDIFF # STORE Q-ERROR, GET BOTH Y,Z CDU ERRORS
TC RTRANSF # FORM R-ERROR IN A (SCALED AT PI RAD)
XCH RDIFF # STORE R-ERROR
# TRANSFORM THE FILTERED Y,Z RATES TO THE Q,R-AXES.
# (THESE MAY BE NEEDED FOR THE RATE DERIVATION FOR THE JETS IF THEY MUST BE USED.)
## Page 592
CAE DCDUZFIL # GET FILTERED Y,Z RATES
TS L # SCALED AT PI/4 RADIANS/SECOND
CAE DCDUYFIL
TC QTRANSF # FOR Q-AXIS RATE
TS OMEGAQ # STORED SCALED AT PI/4 RADIANS/SECOND
CAE DCDUZFIL # GET FILTERED Y,Z RATES
TS L # SCALED AT PI/4 RADIANS/SECOND
CAE DCDUYFIL
TC RTRANSF # FOR R-AXIS RATE
TS OMEGAR # STORED SCALED AT PI/4 RADIANS/SECOND
# TRANSFORM THE FILTERED Y,Z ACCELERATIONS TO THE Q,R-AXES.
# (THESE MAY BE NEEDED TO CALCULATE TRIM GIMBAL OFF-TIMES IF ATTITUDE ERROR HAS GONE BEYOND TRIM GIMBAL CONTROL.)
CAE D2CDUZFL # GET FILTERED Y,Z ACCELERATIONS
TS L # SCALED AT PI/8 RADIANS/SECOND(2)
CAE D2CDUYFL
TC QTRANSF # FORM Q-AXIS ACCELERATION
TS ALPHAQ # STORE AT PI/8 RADIANS/SECOND(2)
CAE D2CDUZFL # GET FILTERED Y,Z ACCELERATIONS
TS L # SCALED AT PI/8 RADIANS/SECOND(2)
CAE D2CDUYFL
TC RTRANSF # FORM R-AXIS ACCELERATION
TS ALPHAR # STORE AT PI/8 RADIANS/SECOND(2)
# EXTRAPOLATE THETA AND OMEGA OVER 100 MS PLUS THE 20 MS DELAY BETWEEN THE KALMAN FILTER AND TRIM GIMBAL
# CONTROL, REFLECTING MECHANICAL LAG.
CAE OMEGAQ
EXTEND
MP DTW
ADS QDIFF
CAE OMEGAR
EXTEND
MP DTW
ADS RDIFF
CAE ALPHAQ
EXTEND
MP DTA
ADS OMEGAQ
CAE ALPHAR
EXTEND
MP DTA
ADS OMEGAR
## Page 593
TCF RESUME
DTW OCT 00754 # 120 MS SCALED AT 4
DTA OCT 01727 # 120 MS SCALED AT 2
# TEST TO SEE IF TRIM GIMBAL CONTROL LAW HAS KEPT BOTH ATTITUDE ERRORS BELOW THE 1 DEGREE BOUNDARY WITH THE REGION
# OF RCS CONTROL LAW DOMINANCE OR IS STILL REDUCING THE ERROR.
GTSTEST CAF TRYGIMBL # VERIFY THAT GTS IS STILL OPERATIVE.
MASK DAPBOOLS
CCS A
TCF RCSCNTRL # GTS NOT OPERATIVE
# START CODING FOR MODULE 3 REMAKE, AUGUST 1967***START CODING FOR MODULE 3 REMAKE, AUGUST 1967*******************
INSERT21 TCF CHKCNTR # GO CHECK TRIMCNTR (AT END OF BANK 21).
# **END CODING FOR MODULE 3 REMAKE, AUGUST 1967*****END CODING FOR MODULE 3 REMAKE, AUGUST 1967*******************
LOOPTEST TS QRCNTR
INDEX QRCNTR
CCS QDIFF # SCALED AT PI.
AD -TGBND+1 # -2 DEG SCALED AT PI, + 1 BIT.
TCF +2
AD -TGBND+1
EXTEND
BZMF +2 # IS ERROR MAG LESS,EQUAL 2 DEG.
TCF TESTPCTR # NO. MAY CONTINUE,THOUGH.
CA QRCNTR # YES. TRY RATE MAGNITUDE.
DOUBLE
INDEX A
# THIS TEST BYPASSES THE TEST IN WSFTEST. CHECK WSFTEST IF BOUND CHANGES.
CCS OMEGAQ # SCALED AT PI/4.
AD -RATBD+1 # -.65 DEC/SEC SCALED AT PI/4 + 1 BIT
TCF +2
AD -RATBD+1
EXTEND
BZMF +2 # IS RATE MAG LESS,EQUAL .65 DEG/SEC.
TCF TESTPCTR # NO. MAY CONTINUE,THOUGH.
CCS QRCNTR # YES. THIS AXIS IS FINE. ARE BOTH DONE.
TCF LOOPTEST # TRY THE Q AXIS NOW.
TCF GTSRAXIS # USE TRIM GIMBAL CONTROL.
-TGBND+1 OCT 77512 # -2 DEG SCALED AT PI, + 1 BIT.
-RATBD+1 OCT 77423 # -.65 DEG/SEC SCALED AT PI/4 + 1 BIT
# ATTITUDE ERROR IS BEYOND TRIM GIMBAL CONTROL LAW RANGE. SET UP FOR RCS CONTROL LAW (Q,R-AXIS) AND CALCULATE
# TIMES TO TURN OFF THE GIMBAL DRIVES.
RCSCNTRL EXTEND # CHANGE LOCATION OF NEXT T5RUPT FROM FIL-
DCA POSTQRFL # TER TO FILDUMMY. AHEM, DON'T FORGET
DXCH T5ADR # THAT FILDUMMY MOVED TO BANK20, DICK GOSS
## Page 594
EXTEND # SET UP POST P-AXIS T5RUPT TO GO TO
DCA QRJPFILT # DUMMYFIL INSTEAD OF FILTER. USE 2CADR
DXCH PFILTADR # BECAUSE DUMMYFIL NOW IN BANK 16.
EXTEND # PREPARE FOR SEQUENCED RESUMPTION OF
DCA CDUY # Q,R-AXIS RCS CONTROL RATE DERIVATION
DXCH OLDYFORQ # BY PROVIDING OLD CDU READINGS
EXTEND # MOVE FILTERED AND TRANSFORMED ATTITUDE
DCA QDIFF # ERRORS INTO ERASABLE FOR Q,R-AXIS RCS
XCH ER # CONTROL URGENCY CALCULATIONS.
LXCH E
CAF ONE
TC WAITLIST
EBANK= DT
2CADR CHEKDRIV # DO TGOFF CALCULATION IN WAITLIST TASK
EXTEND # GO TO Q,R-AXES CONTROL IMMEDIATELY
DCA TGENTRY
DTCB
EBANK= JTSONNOW # NO, SURELY YOU JEST, NOT EBANK 6, AGAIN?
POSTQRFL 2CADR FILDUMMY # WATCH OUT FOR BANK SWITCHING D. GOSS
EBANK= AOSQTERM
QRJPFILT 2CADR DUMMYFIL # NECESSARY BECAUSE DUMMYFIL IN BANK 16.
EBANK= DT
TGENTRY 2CADR STILLRCS
# START CODING FOR MODULE 3 REMAKE, AUGUST 1967***START CODING FOR MODULE 3 REMAKE, AUGUST 1967*******************
CHEKDRIV CCS PASSCTR # ENOUGH FILTER PASSES FOR DRIVE DONE?
TCF COLDFILT # NO. JUST STOP DRIVES.
TCF WARMFILT # YES. CALCULATE TIMES (END OF BANK).
COLDFILT CAF ZERO # FILTER NOT WARM YET. TURN OFF DRIVES.
TS NEGUQ
TS NEGUR
TS QACCDOT
TS RACCDOT
TC WRCHN12
TCF TASKOVER
TC CCSHOLE # FILLER (TO PRESERVE ADDRESSES)
TC CCSHOLE # FILLER (TO PRESERVE ADDRESSES)
# **END CODING FOR MODULE 3 REMAKE, AUGUST 1967*****END CODING FOR MODULE 3 REMAKE, AUGUST 1967*******************
## Page 595
# THE DRIVE SETTING ALGORITHM
# DEL = SGN(OMEGA.K + SGN(ALPHA)ALPHA(2)/2) ONLY +1/-1
# NEGUSUM = ERROR.K(2) + DEL(OMEGA.K.DEL + ALPHA(2)/2)(3/2) + ALPHA(OMEGA.K.DEL + ALPHA(2)/3)
# DRIVE = -SGN(NEGUSUM)
-.04266 DEC -.04266
GTSRAXIS CAF TWO # SET INDEXER FOR R-AXIS CALCULATIONS
TS QRCNTR
TCF USUALXIT
GOQTRIMG CAF ZERO # SET INDEXER FOR Q-AXIS CALCULATIONS
TS QRCNTR
GTSQAXIS EXTEND
INDEX QRCNTR # PICK UP K AND K(2) FOR THIS AXIS
DCA KQ
DXCH KCENTRAL
EXTEND
INDEX QRCNTR # PICK UP OMEGA AND ALPHA FOR THIS AXIS
DCA OMEGAQ
DXCH WCENTRAL
CCS QRCNTR # RDIFF IS STORED IMMEDIATELY FOLLOWING
INDEX A # QDIFF, WITH NO SEPARATING CELL.
CAE QDIFF
# QDIFF IS LESS,EQUAL 2 DEG. AND IS SCALED AT 180 DEG. RESCALE AT 180/64 DEG. = 2 + 13/16 DEG. = PI/64 RADIANS.
EXTEND # RESCALE DIFFERENCE BY MULTIPLYING BY
MP BIT7 # 2(6)
LXCH ETHETA
CAE KCENTRAL # TEST ON MAGNITUDE OF ACCDOT
AD -.04266
EXTEND
BZMF ACCDOTSM # BRANCH IF ACCDOT IS SMALL
ACCDOTLG CAF BIT14 # ACCDOT IS COMPARITIVELY LARGE
TS SF1 # SET UP SCALE FACTORS
CAF BIT12
WSFTEST TS SF2
# LOOPTEST CODING BYPASSES THE OMEGA MAGNITUDE TEST, BUT A CHANGE IN THE TEST BOUNDS COULD REQUIRE ITS USE AGAIN.
# CCS WCENTRAL TEST ON MAGNITUDE OF OMEGA
# AD -.04438
# TCF +2
## Page 596
# AD -.04438
# EXTEND
# BZMF ASFTEST IF SMALL, GO TO ALPHA TEST
# TCF WLARGE
TCF ASFTEST # OMEGA IS ALWAYS BOUNDED BY .65 DEG/SEC.
ACCDOTSM CAE KCENTRAL # RESCALE IF ACCDOT IS SMALL
EXTEND
MP BIT5 # RESCALE K BY MULTIPLYING BY 2(4)
LXCH KCENTRAL
CAE KCENTRAL
EXTEND
SQUARE
TS K2CNTRAL
CAF BIT10 # SET UP VARIABLE SCALE FACTORS
TS SF1
CAF BIT4
TCF WSFTEST # GO TEST ON MAGNITUDE OF OMEGA
ASFTEST CCS ACENTRAL # TEST ON MAGNITUDE OF ALPHA
AD -.08882
TCF +2
AD -.08882
EXTEND
BZMF WARESCAL # IF SMALL, GO TO W,A RESCALING
TCF WLARGE # IF LARGE, DO SAME AS IF W LARGE
# -.04438 DEC -.04438
-.08882 DEC -.08882
WARESCAL CAE WCENTRAL # RESCALE OMEGA BY MULTIPLYING BY 2(4)
EXTEND
MP BIT5
LXCH WCENTRAL
CAE ACENTRAL # RESCALE ALPHA BY MULTIPLYING BY 2(3)
EXTEND
MP BIT4
LXCH ACENTRAL
TCF ALGORTHM
WLARGE CAE SF1 # RESCALE VARIABLE SCALE FACTORS
EXTEND
MP BIT13 # SF1 = SF1*2(-2)
TS SF1
CAE SF2
EXTEND
MP BIT6 # SF2 = SF2*2(-9)
TS SF2
## Page 597
ALGORTHM CAE ETHETA # GET RESCALED ERROR THETA
EXTEND
MP K2CNTRAL # FORM K(2)*THETA IN D.P.
EXTEND
MP SF2 # CALCULATE AND STORE
TS K2THETA # K(2)*THETA*SF2 IN K2THETA
CA WCENTRAL # CALCULATE AND STORE
EXTEND # K*OMEGA*SF1 IN OMEGA.K
MP KCENTRAL
EXTEND
MP SF1
TS OMEGA.K
CA ACENTRAL
EXTEND # BY REDESIGNATION OF THE SCALE FACTOR,
MP A # THIS PRODUCT BECOMES ALPHA(2)/2
TS A2CNTRAL # INSTEAD OF ALPHA(2)
CCS ACENTRAL
CA A2CNTRAL
TCF +2
CS A2CNTRAL # NOW THE A REGISTER CONTAINS
AD OMEGA.K # K*OMEGA + ALPHA*ABS(ALPHA)/2
CCS A
CA BIT1 # DEL = SIGNUM(A) , (ZERO WHEN A IS ZERO),
TCF +2 # PLUS ONE OR MINUS ONE OTHERWISE.
CS BIT1
TS DEL
CCS DEL
CA OMEGA.K
TCF +2
CS OMEGA.K # DEL*OMEGA.K REPLACES OMEGA.K
TS OMEGA.K
AD A2CNTRAL # DEL*OMEGA.K + ALPHA(2)/2
XCH FUNCTION # STORED IN FUNCTION
CA A2CNTRAL
EXTEND # CALCULATE ALPHA(2)/3
MP .66667
AD OMEGA.K
EXTEND
MP ACENTRAL # K(2)*THETA+ALPHA*(DEL*OMEG.K+ALPHA(2)/3)
ADS K2THETA # FIRST AND SECOND TERMS SUMMED HERE.
# THE FOLLOWING SECTION CALCULATES .707*DEL*FUNCTION(3/2) AND ADDS IT TO THE OTHER TWO TERMS OF NEGUSUM.
## Page 598
CA SR # CALL SEQUENCE FOR SPROOT REQUIRES THAT
AD A # SR BE PRESERVED BY THE CALLER.
XCH STORCDUY # THE KALMAN FILTER STORES INTO THE CELL
CA FUNCTION # STORCDUY BEFORE USING IT OTHERWISE.
TC SPROOT
LXCH STORCDUY
LXCH SR
EXTEND
MP FUNCTION
XCH STORCDUY
CCS DEL
CA .707GTS # THIS CELL CONTAINS SQUARE ROOT OF 1/2
TCF +2
CS .707GTS
EXTEND
MP STORCDUY
AD K2THETA # NEGUSUM IS COMPLETE.
CCS A # SIGNUM(NEGUSUM) IS NEGATIVE OF THE SIGN
CA BIT1 # WHICH WILL BE ATTACHED TO THE NEW VALUE
TCF POSDRIVE # OF Q(R)ACCDOT.
CS BIT1
POSDRIVE INDEX QRCNTR # SIGN OF NEW Q(R)ACCDOT OPPOSES THIS SIGN
TS NEGUQ
COM
EXTEND # SEND BACK JERK TERM
INDEX ITEMP6
MP ACCDOTQ
INDEX ITEMP6
LXCH QACDOTMP # STORE FOR 100 MS, THEN RELEASE TO FILTER
CCS QRCNTR # LOOP COUNTER
TC SLECTLAW # 2ND PASS. (FOR Q-AXIS)
# TRANSFORM JERKS BACK TO GIMBAL AXES.
CS QACCDOT # SCALED AT PI/2(7), AND COMPLEMENTED.
EXTEND
MP MR12 # SCALED AT 2
TS Y3DOT
CS RACCDOT # SCALED AT PI/2(7), AND COMPLEMENTED.
EXTEND
MP MR13 # SCALED AT 2
ADS Y3DOT
ADS Y3DOT # SCALED AT PI/2(7)
CS QACCDOT # SCALED AT PI/2(7), AND COMPLEMENTED.
EXTEND
MP MR22 # SCALED AT 1
## Page 599
TS Z3DOT
CS RACCDOT # SCALED AT PI/2(7), AND COMPLEMENTED.
EXTEND
MP MR23 # SCALED AT 1
ADS Z3DOT # SCALED AT PI/2(7)
TC WRCHN12 # SEND GIMBAL DRIVES TO SERVOS
TCF RESUME # WAIT UNTIL NEXT TRIM GIMBAL RUPT
# WAITLIST TASKS TO SET TRIM GIMBAL TURN OFF BITS.
OFFGIMQ CAF ZERO # SET Q-AXIS FLAG TO ZERO
TS NEGUQ
TCF +3
OFFGIMR CAF ZERO # SET R-AXIS FLAG TO ZERO
TS NEGUR
TC WRCHN12 # FLAGS TO CHANNEL BITS
TCF TASKOVER
# THE WRCHN12 SUBROUTINE SETS BITS 9,10,11,12 OF CHANNEL 12 ON THE BASIS OF THE CONTENTS OF NEGUQ,NEGUR WHICH ARE
# THE NEGATIVES OF THE TRIM GIMBAL DESIRED DRIVES.
BGIM OCTAL 07400
CHNL12 EQUALS ITEMP6
WRCHN12 CCS NEGUQ
CAF BIT10
TCF +2
CAF BIT9
TS CHNL12
CCS NEGUR
CAF BIT12
TCF +2
CAF BIT11
ADS CHNL12 # (STORED RESULT NOT USED AT PRESENT)
CS BGIM
EXTEND
WAND 12
CA CHNL12
EXTEND
WOR 12
TC Q # SIMPLE RETURN ALWAYS
# Q,R-TRANSF TRANSFORMS A Y,Z GIMBAL COORDINATE VARIABLE PAIR (IN A,L) TO PILOT COORDINATES (Q/R), RETURNED IN A.
# (THE MATRIX M FROM GIMBAL TO PILOT AXES IS ASSUMED TO BE DONE BY T4RUPT AND SCALED AT +1.)
QRERAS EQUALS ITEMP6
## Page 600
QTRANSF LXCH QRERAS # SAVE Z-AXIS VARIABLE
EXTEND
MP M21 # (Y-AXIS)*M21
XCH QRERAS # SAVE, GET Z-AXIS VARIABLE
EXTEND
MP M22 # (Z-AXIS)*M22
AD QRERAS # SUM = (Y-AXIS)*M21 + (Z-AXIS)*M22
TC Q # RETURN WITH SUM IN A
RTRANSF LXCH QRERAS # SAVE Z-AXIS VARIABLE
EXTEND
MP M31 # (Y-AXIS)*M31
XCH QRERAS # SAVE, GET Z-AXIS VARIABLE
EXTEND
MP M32 # (Z-AXIS)*M32
AD QRERAS # SUM = (Y-AXIS)*M31 + (Z-AXIS)*M32
TC Q # RETURN WITH SUM IN A
.66667 DEC .66667
.707GTS DEC 0.70711
(2/3) DEC 0.66667
## Page 601
# SUBROUTINE: TGOFFCAL MOD. NO. 1 DATE: AUGUST 22, 1966
# START CODING FOR MODULE 3 REMAKE, AUGUST 1967***START CODING FOR MODULE 3 REMAKE, AUGUST 1967*******************
# PROGRAM DESIGN BY: RICHARD D. GOSS (MIT/IL)
# PROGRAM IMPLEMENTATION BY: JONATHAN D. ADDELSTON (ADAMS ASSOCIATES)
# MODIFIED 30 NOV 66, TO USE ACCDOTQ AND ACCDOTR. CRAIG WORK
# MODIFIED AUGUST '67 TO CHANGE CALLING SEQUENCE AND MAKE MAXTIME ERASABLE PETER WEISSMAN
# THIS SUBROUTINE CALCULATES THE TRIM GIMBAL SHUTDOWN TIME FOR EITHER THE Q OR THE R AXIS (DEPENDING ON THE
# CALLING SEQUENCE). THIS TIME IS SCALED FOR IMMEDIATE USE BY A WAITLIST CALL AS SHOWN IN THE CALLING SEQUENCES.
# IF THE TIME-TO-GO IS MORE THAN 'DRIVELIM', IT IS LIMITED TO 'MAXTIME'. IF
# THE TIME-TO-GO IS LESS THAN TEN MILLISECONDS, THE SHUTDOWN IS PERFORMED IMMEDIATELY AND THE WAITLIST CALL IS
# BY-PASSED.
# THESE TIME-TO-GO CALCULATIONS ARE DESIGNED TO DRIVE THE TRIM GIMBAL TO A POSITION WHERE THE DESCENT ENGINE WILL
# CAUSE NO ANGULAR ACCELERATION. THIS SUBROUTINE IS CALLED ONLY FROM THE WAITLIST TASK CHEKDRIV WHICH IS
# INITIATED ONLY WHEN THE TRIM GIMBAL CONTROL LAW HAS LOST CONTROL OF THE LEM VEHICLE ATTITUDE AND MUST RETURN TO
# THE USE OF REACTION CONTROL SYSTEM JETS.
# CALLING SEQUENCES:
# CAF ZERO INDEX FOR Q-AXIS.
# TC TGOFFCAL
# CAF NEGMAX RETURN HERE FOR NO Q DRIVE.
# TS (QTIME) RETURN HERE WITH TIME IN A (DECASECONDS)
# CAF TWO INDEX FOR R-AXIS.
# TC TGOFFCAL
# CAF NEGMAX RETURN HERE FOR NO R DRIVE.
# TS (RTIME) RETURN HERE WITH TIME IN A (DECASECONDS)
# SUBROUTINES CALLED: NONE, BUT WRCHNL12 IS CALLED AFTER BOTH TGOFFCALL CALLS.
# NORMAL EXITS: TO WAITLIST CALL OR BEYOND 2CADR IN CALLING SEQUENCE AS SPECIFIED ABOVE.
# ALARM OR ABORT EXIT MODES: NONE
# INPUT: 1. THE AXIS INDEXER: 0 FOR Q, 2 FOR R (SEE CALLING SEQUENCES)
# 2. THE SIGNED TIME DERIVATIVE OF ACCELERATION (QACCDOT OR RACCDOT) SCALED AT PI/2(7) RAD/SEC(3).
# 3. THE ACCELERATION APPROXIMATION FROM THE DESCENT KALMAN FILTER TRANSFORMED TO PILOT AXES (ALPHAQ OR
# ALPHAR) SCALED AT PI/8 RAD/SEC(2).
# 4. CHANNEL 12 CONTAINS THE GIMBAL DRIVES AND OTHER BITS.
# OUTPUT 5. THE NEGATIVE GIMBAL DRIVE FLAG (NEGUQ AND NEGUR) WHERE A +1 BIT REQUESTS POSITIVE GIMBAL DRIVE
# (ANGULAR ACCELERATION DECREASING), A -1 BIT REQUESTS NEGATIVE GIMBAL DRIVE (ANG. ACC. INCREASING).
# A ZERO INDICATES NO DRIVE.
# 6. TIME REQUIRED TO ZERO OFFSET, SCALED FOR Q(R)GIMTIMR.
## Page 602
# ERASABLE STORAGE CONFIGURATION (NEEDED BY THE INDEXING METHODS):
# NEGUQ ERASE +2 NEGATIVE OF Q-AXIS GIMBAL DRIVE
# (SPWORD) EQUALS NEGUQ +1 ANY S.P. ERASABLE NUMBER, NOW THRSTCMD
# NEGUR EQUALS NEGUQ +2 NEGATIVE OF R-AXIS GIMBAL DRIVE
# ACCDOTQ ERASE +2 Q-JERK TERM SCALED AT PI/2(7) RAD/SEC(3)
# (SPWORD) EQUALS ACCDOTQ +1 ANY S.P. ERASABLE NUMBER NOW QACCDOT
# ACCDOTR EQUALS ACCDOTQ +2 R-JERK TERM SCALED AT PI/2(7) RAD/SEC(3)
# ACCDOTQ,ACCDOTR ARE MAGNITUDES.
# ALPHAQ ERASE +2 Q-AXIS ACCELERATION SCALED AT PI/8 R/S2
# (SPWORD) EQUALS ALPHAQ +1 ANY S.P. ERASABLE NUMBER, NOW OMEGAR
# ALPHAR EQUALS ALPHAQ +2 R-AXIS ACCELERATION SCALED AT PI/8 R/S2
# NOTE: NOW OMEGAP,OMEGAQ PRECEDE ALPHAQ
# DEBRIS: L, Q, ITEMP1, ITEMP2, ITEMP6
TGOFFCAL TS QRNDXER # Q OR R AXIS INDEXER
INDEX QRNDXER # GET JERK TERM MAGNITUDE SCALED AT
CAE ACCDOTQ # PI/2(7) IN RADIANS/SEC(3).
EXTEND # UNLESS THETA TRIPLE-DOT MAGNITUDE IS NON
BZMF TGOFFNOW # -ZERO, SET DRIVE TO ZERO NOW.
TS NZACCDOT # SAVE NON-ZERO DENOMINATOR.
INDEX QRNDXER # INITIALIZE THE AOSTERM WHICH WILL BE UP-
CAE ALPHAQ # DATED IN THE DUMMYFIL CALCULATION FOR
EXTEND # USE IN THE QRAXIS RATE DERIVATION. SET
MP .1-.05K) # AOSTERM TO ALPHA*CSP*(1-.5*K), WHERE CSP
XCH L # IS .1 SEC, K IS .5 THEN AOSTERM IS SET
CCS QRNDXER # TO .075*ALPHA, SCALED AT PI/4,WHILE
INDEX A # ALPHA IS SCALED AT PI/8( THE CONSTANT IS
LXCH AOSQTERM # SCALED AT 2.
INDEX QRNDXER # GET ACCELERATION SCALED AT PI/8
CAE ALPHAQ # RAD/SEC(2).
EXTEND # IF ACCELERATION IS ALREADY ZERO, EXIT.
BZF TGOFFNOW # OTHERWISE, PROCEED WITH NON-ZERO ALPHA.
EXTEND # SET NEGUQ TO THE SIGN OF ALPHA. THEN USE
BZMF NEGALPH # THE MAGNITUDE OF ALPHA TO COMPUTE TIME
TS ITEMP6
CAF BIT1
TCF +4
NEGALPH CS A
TS ITEMP6
CS BIT1
INDEX QRNDXER # STORE THE DRIVE DIRECTION FLAG
TS NEGUQ # TIME = MAGNITUDE OF (ALPHA/ACCDOT),
# MINUS THE SIGN OF Q(R)ACCDOT LEFT IN A.
EXTEND # STORE ACCDOT TO REFLECT THE CHANGE IN
INDEX QRNDXER # GIMBAL DRIVE DIRECTION (POSSIBLE). THIS
## Page 603
MP ACCDOTQ # CAN BE ESSENTIAL FOR DUMMYFIL, IN CASE
INDEX QRNDXER # Q(R)ACCDOT IS NOT INITIALIZED BEFORE
LXCH QACCDOT # EXECUTING DUMMYFIL.
CAE NZACCDOT # WILL ALPHA/ACCDOT EXCEED MAX DRIVE TIME?
EXTEND
MP DRIVELIM # MAX DRIVE TIME AT 16 SEC (ERASABLE LOAD)
EXTEND
SU ITEMP6 # 15*ACCDOT - ABS(ALPHA) AT PI/8
EXTEND
BZMF USEMAX # LARGE T. USE MAX DRIVE TIME INSTEAD.
CAE ITEMP6 # DRIVE IME = ABS(ALPHA/ACCDOT)
EXTEND # RESCALE QUOTIENT TO TIMER(ERASABLE LOAD)
INDEX QRNDXER
MP DRIVFACQ # (10 SCALED AT 2(10)) X (DAMPING FACTOR)
EXTEND
DV NZACCDOT
ZEROTEST EXTEND # BE SURE WAITLIST TIME IS GREATER THAN 0.
BZMF TGOFFNOW
TCF +2 # IT IS, RETURN.
USEMAX CAE MAXTIME # USE MAXIMUM DRIVE TIME.
+2 INDEX Q # RETURN TO Q+1 WITH TIME IN A.
TC 1
TGOFFNOW CAF ZERO # MAKE SURE PLUS ZERO FOR DRIVE FLAG
INDEX QRNDXER # TURN OFF DRIVE FLAG NOW
TS NEGUQ
TC Q # RETURN TO Q ( WITHOUT A DRIVE TIME).
TC CCSHOLE # (FILLER)
# **END CODING FOR MODULE 3 REMAKE, AUGUST 1967*****END CODING FOR MODULE 3 REMAKE, AUGUST 1967*******************
QRNDXER EQUALS ITEMP1 # INDEXER FOR Q OR R AXIS
NZACCDOT EQUALS ITEMP2 # TEMPORARY STORAGE FOR NON-ZERO ACCDOT
-2MINWL DEC -12000 # - 2 MINUTES SCALED FOR WAITLIST
-2MIN256 DEC -.46875 # - 2 MINUTES SCALED AT 256
128/164 OCTAL 31000 # 128/163.84 CONVERTING 256 TO WAITLIST/2
.1-.05K) OCTAL 01146 # .0375=.075 SCALED AT 2
# START CODING FOR MODULE 3 REMAKE, AUGUST 1967***START CODING FOR MODULE 3 REMAKE, AUGUST 1967*******************
TESTCNTR CCS SIMPCNTR # USE BIGBOX FOR PASSCTR INITIALIZATION
TCF BIGLOAD # UNTIL SIMPCNTR IS +0. THEN USE COUNTBOX.
CAE COUNTBOX
TCF LOADCNTR
## Page 604
BIGLOAD CAE BIGBOX
TCF LOADCNTR
# **END CODING FOR MODULE 3 REMAKE, AUGUST 1967*****END CODING FOR MODULE 3 REMAKE, AUGUST 1967*******************
# THE NEXT FIVE CELLS ARE LEFT IN FOR SPACING.
ADS FUNCTION +1 # MULTIPLIER AS C(A). MULTIPLY THESE AND
TS L # USE ONLY HIGH ORDER PART OF PRODUCT.
TCF +2 # ADD S.P. LOW PRODUCT TO LOW PART OF HIGH
ADS FUNCTION # PRODUCT. CHECK OVERFLOW, CARRY, AND
TC Q # RETURN.
