RCS-CSM_DIGITAL_AUTOPILOT.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: RCS-CSM_DIGITAL_AUTOPILOT.agc
## Purpose: A section of Artemis revision 071.
## It is part of the reconstructed source code for the first
## release of the flight software for the Command Module's
## (CM) Apollo Guidance Computer (AGC) for Apollo 15 through
## 17. The code has been recreated from a copy of Artemis 072.
## It has been adapted such that the resulting bugger words
## exactly match those specified for Artemis 071 in NASA
## drawing 2021154-, which gives relatively high confidence
## that the reconstruction is correct.
## Reference: 1000
## Assembler: yaYUL
## Contact: Ron Burkey <info@sandroid.org>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 2019-08-14 MAS Created from Artemis 072.
## Page 1000
# T5 INTERRUPT PROGRAM FOR THE RCS-CSM AUTOPILOT
# START OF T5 INTERRUPT PROGRAM
SETLOC DAPS3
BANK
COUNT* $$/DAPRC
EBANK= KMPAC
REDORCS LXCH BANKRUPT # RESTART OF AUTOPILOT COMES HERE
CA T5PHASE # ON A T5 RUPT.
EXTEND
BZMF +2 # IF T5PHASE +0, -0, OR -, RESET TO -
TCF +3 # IF T5PHASE +, LEAVE IT +. DO A FRESHDAP
CS ONE
TS T5PHASE
EXTEND
DCA RCSLOC
DXCH T5LOC # HOOK UP T5RUPT TO AUTOPILOT
TCF RCSATT +1
EBANK= KMPAC
RCSLOC 2CADR RCSATT
RCSATT LXCH BANKRUPT # SAVE BB
+1 EXTEND # SAVE Q
QXCH QRUPT
CAF BIT15 # BIT15 CHAN31 = 0 IF IMU POWER IS ON AND
TC C31BTCHK # S/C CONT SW IS IN CMC (I.E. IF G/C DAP
TCF SETT5 # IS FULLY ENABLED). IF SO8
# GO TO SETT5
CS RCSFLAGS # IF G/C AUTOPILOT IS NOT FULLY ENABLED,
MASK BIT14
ADS RCSFLAGS # SET NORATE FLAG,
CAF POSMAX
TS HOLDFLAG # SET HOLDFLAG +,
CAF ZERO # ZERO ERRORX, ERRORY, AND ERRORZ,
TS ERRORX
TS ERRORY
TS ERRORZ
CAF BIT14
TC C31BTCHK # AND CHECK FREE FUNCTION (BIT14 CHAN31)
TCF SETT5
TS T5PHASE # IF NOT IN FREE MODE,
CAF OCT37766 # SCHEDULE REINITIALIZATION (FRESHDAP)
TS TIME5 # IN 100 MS VIA T5RUPT
TCR ZEROJET # ZERO JET CHANNELS IN 14 MS VIA ZEROJET
## Page 1001
TCF KMATRIX
DELTATT OCT 37770 # 80MS (TIME5)
DELTATT2 = OCT37776 # 20 MS (TIME5)
# CHECK PHASE OF T5 PROGRAM
#
# BECAUSE OF THE LENGTH OF THE T5 PROGRAM, IT HAS BEEN DIVIDED INTO
# THREE PARTS, T5PHASE1, T5PHASE2, AND THE JET SELECTION LOGIC,
# TO ALLOW FOR THE EXECUTION OF OTHER
# INTERRUPTS. T5PHASE IS ALSO USED IN THE INITIALIZATION OF THE AUTOPILOT
# VARIABLES AT TURN ON.
# THE CODING OF T5PHASE IS...
#
# + = INITIALIZE T5 RCS-CSM AUTOPILOT
# T5PHASE = +0 = PHASE2 OF THE T5 PROGRAM
# - = RESTART DAP
# -0 = PHASE1 OF THE T5 PROGRAM
SETT5 CCS T5PHASE
TCF FRESHDAP # TURN ON AUTOPILOT
TCF T5PHASE2 # BRANCH TO PHASE2 OF PROGRAM
TCF REDAP # RESTART AUTOPILOT
TS T5PHASE # PHASE 1 RESET FOR PHASE 2
CA TIME5
TS T5TIME # USED IN COMPENSATING FOR DELAYS IN T5
CAF DELTATT2 # RESET FOR T5RUPT IN 20MS FOR PHASE2
TS TIME5 # OF PROGRAM
## Page 1002
# IMU STATUS CHECK
CS IMODES33 # CHECK IMU STATUS
MASK NOIMUDAP # BIT6 = 0 IMU OK
CCS A # BIT6 = 1 NO IMU
TCF RATEFILT
FREECHK CS RCSFLAGS # BIT14 INDICATES THAT RATES HAVE NOT BEEN
MASK BIT14 # INITIALIZED
ADS RCSFLAGS
CAF BIT14 # NO ATTITUDE REFERENCE
TS HOLDFLAG # STOP ANY AUTOMATIC STEERING AND PREPARE
# TO PICK UP CDU ANGLES UPON RESUMPTION OF
# ATTITUDE HOLD
TC C31BTCHK # CHECK FOR FREE MODE
TCF KRESUME1 # IN FREE, PROVIDE FREE CONTROL ONLY
TCF REINIT # .....TILT...............................
BITS4,5 = BITS4&5
RATEFILT CA RCSFLAGS # SEE IF RATEFILTER HAS BEEN INITIALIZED
MASK BIT14
EXTEND # IF SO, PROCEED WITH RATE DERIVATION
BZF +2
TCF KMATRIX # IF NOT, SKIP RATE DERIVATION
# RATE FILTER TIMING = 7.72 MS
#
# RATE FILTER EQUATIONS
# DRHO = DELRHO - (.1)ADOT + (1 - GAIN1)DRHO
# -1
# ADOT = ADOT + GAIN2 DRHO + KMJ DFT
# -1
# - * - -
# WHERE DELRHO = AMGB (CDU - CDU )
# -1
+2 CAF TWO
DRHOLOOP TS SPNDX
DOUBLE
TS DPNDX
INDEX DPNDX
CS DRHO # DRHO SCALED 180 DEGS
EXTEND
INDEX ATTKALMN # PICK UP DESIRED FILTER GAIN
MP GAIN1
INDEX DPNDX
DAS DRHO # (1 -.064) DRHO
EXTEND
INDEX DPNDX
DCS ADOT
## Page 1003
DXCH KMPAC # -(.1)ADOT
CA QUARTER
TC SMALLMP
DXCH KMPAC
INDEX DPNDX
DAS DRHO
CCS SPNDX
TCF DRHOLOOP
CA CDUX # MEASURED BODY RATES--
XCH RHO
EXTEND
MSU RHO # - * - -
COM # DELRHO = AMGB (CDU - CDU )
# -1
ZL
DXCH DELTEMPX
CA CDUY
XCH RHO1
EXTEND
MSU RHO1
COM
TS T5TEMP # (CDUY - RHO1) SCALED 90 DEGS
EXTEND
MP AMGB1
DAS DELTEMPX # DELTEMPX = (CDUX-RHO) + AMGB1(CDUY-RHO1)
# MUST BE DOUBLE PRECISION OR WILL LOSE
# PULSES
CA AMGB4
EXTEND
MP T5TEMP
DXCH DELTEMPY
CA AMGB7
EXTEND
MP T5TEMP
DXCH DELTEMPZ
CA CDUZ
XCH RHO2
EXTEND
MSU RHO2
COM
TS T5TEMP # (CDUZ - RHO2) SCALED 90 DEGS
EXTEND
MP AMGB5
DAS DELTEMPY # DELTEMPY = AMGB4(CDUY-RHO1)
# + AMGB5(CDUZ-RHO2)
CA AMGB8
EXTEND
MP T5TEMP
DAS DELTEMPZ # DELTEMPZ = AMGB7(CDUY-RHO1)
## Page 1004
# + AMGB8(CDUZ-RHO2)
CAF TWO
ADOTLOOP TS SPNDX
DOUBLE
TS DPNDX
EXTEND
INDEX DPNDX
DCA DELTEMPX
INDEX DPNDX
DAS DRHO
EXTEND
INDEX DPNDX
DCA DELTEMPX
INDEX DPNDX
DAS MERRORX
INDEX DPNDX
CA DRHO
DOUBLE # N.B.
DOUBLE # N.B.
EXTEND
INDEX ATTKALMN # PICK UP DESIRED FILTER GAINS
MP GAIN2
INDEX DPNDX # ADOT + (.16)(.1)DRHO
DAS ADOT # -1
INDEX SPNDX # S/C TORQUE TO INERTIA RATIO
CA KMJ # SCALED (450)(1600)/(57.3)(16384)=1/1.3
EXTEND
INDEX SPNDX
MP DFT
INDEX DPNDX
DAS ADOT # KMJ(DFT)
CCS SPNDX
TCF ADOTLOOP # END CALCULATION OF VEHICLE RATES
KMATRIX CA ATTSEC
MASK LOW4
CCS A
TCF TENTHSEK
CAF PRIO34 # CALL FOR 1 SEC UPDATE OF TRANSFORMATION
TC NOVAC # MATRIX FROM GIMBAL AXES TO BODY AXES
EBANK= KMPAC
2CADR AMBGUPDT
CAF NINE
TENTHSEK TS ATTSEC
## Page 1005
# WHEN AUTOMATIC MANEUVERS ARE BEING PERFORMED, THE FOLLOWING ANGLE ADDITION MUST BE MADE TO PROVIDE A SMOOTH
# SEQUENCE OF ANGULAR COMMANDS TO THE AUTOPILOT--
#
# CDUXD = CDUXD + DELCDUX (DOUBLE PRECISION)
# CDUYD = CDUYD + DELCDUY (DOUBLE PRECISION)
# CDUZD = CDUZD + DELCDUZ (DOUBLE PRECISION)
#
# THE STEERING PROGRAMS-
# 1) ATTITUDE MANEUVER ROUTINE
# 2) LEM TRACKING
#
# SHOULD GENERATE THE DESIRED ANGLES (CDUXD, CDUYD, CDUZD) AS WELL AS THE INCREMENTAL ANGLES (DELCDUX, DELCDUY,
# DELCDUZ) SO THAT THE GIMBAL ANGLE COMMANDS CAN BE INTERPOLATED BETWEEN UPDATES.
#
# HOLDFLAG CODING-
#
# + = GRAB PRESENT CDU ANGLES AND STORE IN THETADX, THETADY, THETADZ
# AND PERFORM ATTITUDE HOLD ABOUT THESE ANGLES
# ALSO IGNORE AUTOMATIC STEERING
# SET = + BY
# 1) INITIALIZATION PHASE OF AUTOPILOT
# 2) OCCURANCE OF RHC COMMANDS
# 3) FREE MODE
# 4) SWITCH OVER TO ATTITUDE HOLD FROM AUTO
# WHILE DOING AUTOMATIC STEERING (IN THIS CASE
# HOLDFLAG IS NOT ACTUALLY SET TO +, BUT THE LOGIC
# FUNCTIONS AS IF IT WERE.)
# 5) S/C CONTROL SWITCH IN SCS
# 6) IMU POWER OFF
# +0 = IN ATTITUDE HOLD ABOUT A PREVIOUSLY ESTABLISHED REFERENCE
# - = PERFORMING AUTOMATIC MANEUVER
# -0 = NOT USED AT PRESENT
#
# NOTE THAT THIS FLAG MUST BE SET = - BY THE STEERING PROGRAM IF IT IS TO COMMAND THE AUTOPILOT.
# SINCE ASTRONAUT ACTION MAY CHANGE THE HOLDFLAG SETTING, IT SHOULD BE MONITORED BY THE STEERING PROGRAM TO
# DETERMINE IF THE AUTOMATIC SEQUENCE HAS BEEN INTERRUPTED AND IF SO, TAKE APPROPRIATE ACTION.
CS HOLDFLAG
EXTEND
BZMF DACNDLS # IF HOLDFLAG +0,-0,+, BYPASS AUTOMATIC
# COMMANDS
DCDUINCR CAF TWO
DELOOP TS SPNDX
DOUBLE
TS DPNDX
EXTEND
INDEX A
DCA CDUXD
## Page 1006
DXCH KMPAC
EXTEND
INDEX DPNDX
DCA DELCDUX
TC DPADD
EXTEND
DCA KMPAC
INDEX SPNDX
TS THETADX
INDEX DPNDX
DXCH CDUXD
CCS SPNDX
TCF DELOOP
## Page 1007
# RCS-CSM AUTOPILOT ATTITUDE ERROR DISPLAY
#
# THREE TYPES OF ATTITUDE ERRORS MAY BE DISPLAYED ON THE FDAI-
#
# MODE 1) AUTOPILOT FOLLOWING ERRORS SELECTED BY V61E
# GENERATED INTERNALLY BY THE AUTOPILOT
#
# MODE 2) TOTAL ATTITUDE ERRORS SELECTED BY V62E
# WITH RESPECT TO THE CONTENTS OF N22
#
# MODE 3) TOTAL ASTRONAUT ATTITUDE ERRORS SELECTED BY V63E
# WITH RESPECT TO THE CONTENTS OF N17
#
# MODE 1 IS PROVIDED AS A MONITOR OF THE RCS DAP AND ITS ABILITY TO TRACK AUTOMATIC STEERING COMMANDS. IN THIS
# MODE THE ATTITUDE ERRORS WILL BE ZEROED WHEN THE CMC MODE SWITCH IS IN FREE
#
# MODE 2 IS PROVIDED TO ASSIST THE CREW IN MANUALLY MANEUVERING THE S/C TO THE ATTITUDE (GIMBAL ANGLES) SPECIFIED
# IN N22. THE ATTITUDE ERRORS WRT THESE ANGLES AND THE CURRENT CDU ANGLES ARE RESOLVED INTO S/C CONTROL AXES
# AS A FLY-TO INDICATOR.
#
# MODE 3 IS PROVIDED TO ASSIST THE CREW IN MANUALLY MANEUVERING THE S/C TO THE ATTITUDE (GIMBAL ANGLES) SPECIFIED
# IN N17. THE ATTITUDE ERRORS WRT THESE ANGLES AND THE CURRENT CDU ANGLES ARE RESOLVED INTO S/C CONTROL AXES
# AS A FLY-TO INDICATOR.
#
# V60 IS PROVIDED TO LOAD N17 WITH A SNAPSHOT OF THE CURRENT CDU ANGLES, THUS SYNCHRONIZING THE MODE 3 DISPLAY
# WITH THE CURRENT S/C ATTITUDE. THIS VERB MAY BE USED AT ANY TIME.
#
# THESE DISPLAYS WILL BE AVAILIABLE IN ANY MODE (AUTO, HOLD, FREE, G+N, OR SCS) ONCE THE RCS DAP HAS BEEN
# INITIATED VIA V46E. MODE 1, HOWEVER, WILL BE MEANINGFUL ONLY IN G+N AUTO OR HOLD. THE CREW MAY PRESET (VIA
# V25N17) AN ATTITUDE REFERENCE (DESIRED GIMBAL ANGLES) INTO N17 AT ANY TIME.
DACNDLS CS RCSFLAGS # ALTERNATE BETWEEN FDAIDSP1 AND FDAIDSP2
MASK BIT4
EXTEND
BZF FDAIDSP2
FDAIDSP1 ADS RCSFLAGS
TC NEEDLER
KRESUME1 TCF RESUME # END PHASE 1
## Page 1008
# FDAI ATTITUDE ERROR DISPLAY SUBROUTINE
#
# PROGRAM DESCRIPTION: D. KEENE 5/24/67
#
# THIS SUBROUTINE IS USED TO DISPLAY ATTITUDE ERRORS ON THE FDAI VIA THE DIGITAL TO ANALOG CONVERTERS (DACS)
# IN THE CDUS. CARE IS TAKEN TO METER OUT THE APPROPRIATE NUMBER OF PULSES TO THE IMU ERROR COUNTERS AND PREVENT
# OVERFLOW, TO CONTROL THE RELAY SEQUENCING, AND TO AVOID INTERFERENCE WITH THE COARSE ALIGN LOOP WHICH ALSO USES
# THE DACS.
#
#
# CALLING SEQUENCE:
#
# DURING THE INITIALIZATION SECTION OF THE USER'S PROGRAM, BIT3 OF RCSFLAGS SHOULD BE SET TO INITIATE THE
# TURN-ON SEQUENCE WITHIN THE NEEDLES PROGRAM:
#
# CS RCSFLAGS IN EBANK6
# MASK BIT3
# ADS RCSFLAGS
#
# THEREAFTER, THE ATTITUDE ERRORS GENERATED BY THE USER SHOULD BE TRANSFERED TO THE FOLLOWING LOCATIONS IN EBANK6:
#
# AK SCALED 180 DEGREES NOTE: THESE LOCATIONS ARE SUBJECT
# AK1 SCALED 180 DEGREES TO CHANGE
# AK2 SCALED 180 DEGREES
#
# FULL SCALED DEFLECTION CORRESPONDS TO 16 7/8 DEGREES OF ATTITUDE ERROR
# (= 384 BITS IN IMU ERROR COUNTER)
#
# A CALL TO NEEDLER WILL THEN UPDATE THE DISPLAY:
#
# INHINT
# TC IBNKCALL NOTE: EBANK SHOULD BE SET TO E6
# CADR NEEDLER
# RELINT
#
# THIS PROCESS SHOULD BE REPEATED EACH TIME THE ERRORS ARE UPDATED. AT LEAST 3 PASSES THRU THE PROGRAM ARE
# REQUIRED BEFORE ANYTHING IS ACTUALLY DISPLAYED ON THE ERROR METERS.
# NOTE: EACH CALL TO NEEDLER MUST BE SEPARATED BY AT LEAST 50MS TO ASSURE PROPER RELAY SEQUENCING.
#
# ERASABLE USED:
# AK CDUXCMD
# AK1 CDUYCMD
# AK2 CDUZCMD
# EDRIVEX A,L,Q
# EDRIVEY T5TEMP
# EDRIVEZ SPNDX
#
# SWITCHES: RCSFLAGS BITS 3,2
#
# I/O CHANNELS: CHAN12 BIT 4 (COARSE ALIGN - READ ONLY)
## Page 1009
# CHAN12 BIT 6 (IMU ERROR COUNTER ENABLE)
# CHAN14 BIT 13,14,15 (DAC ACTIVITY)
#
# SIGN CONVENTION< AK = THETAC - THETA
# WHERE THETAC = COMMAND ANGLE
# THETA = PRESENT ANGLE
NEEDLER CAF BIT4 # CHECK FOR COARSE ALIGN ENABLE
EXTEND # IF IN COARSE ALIGN DO NOT USE IMU
RAND CHAN12 # ERROR COUNTERS. DONT USE NEEDLES
EXTEND
BZF NEEDLER1
RCSINT CS RCSFLAGS # SET BIT3 FOR INITIALIZATION PASS
MASK BIT3
ADS RCSFLAGS
TC Q
NEEDLER1 CA RCSFLAGS
MASK SIX
EXTEND
BZF NEEDLES3
MASK BIT3
EXTEND
BZF NEEDLER2 # BIT3 = 0, BIT2 = 1
CS BIT6 # FIRST PASS BIT3 = 1
EXTEND # DISABLE IMU ERROR COUNTER TO ZERO DACS
WAND CHAN12 # MUST WAIT AT LEAST 60 MS BEFORE
NEEDLE11 CS ZERO # ENABLING COUNTERS.
TS AK # ZERO THE INPUTS ON FIRST PASS
TS AK1
TS AK2
TS EDRIVEX # ZERO THE DISPLAY REGISTERS
TS EDRIVEY
TS EDRIVEZ
TS CDUXCMD # ZERO THE OUT COUNTERS
TS CDUYCMD
TS CDUZCMD
CS SIX # RESET RCSFLAGS FOR PASS2
MASK RCSFLAGS
AD BIT2
TS RCSFLAGS
TC Q # END PASS1
NEEDLER2 CAF BIT6 # ENABLE IMU ERROR COUNTERS
EXTEND
WOR CHAN12
CS SIX # RESET RCSFLAGS TO DISPLAY ATTITUDE
## Page 1010
MASK RCSFLAGS # ERRORS WAIT AT LEAST 4 MS FOR
TS RCSFLAGS # RELAY CLOSURE
TC Q
NEEDLES3 CAF BIT6 # CHECK TO SEE IF IMU ERROR COUNTER
EXTEND # IS ENABLED
RAND CHAN12
EXTEND # IF NOT RECYCLE NEEDLES
BZF RCSINT
NEEDLES CAF TWO
DACLOOP TS SPNDX
CS QUARTER
EXTEND
INDEX SPNDX
MP AK
TS L
CCS A
CA DACLIMIT
TCF +2
CS DACLIMIT
AD L
TS T5TEMP # OVFLO CHK
TCF OVSPOT
INDEX A # ON OVERFLOW LIMIT OUTPUT TO +-384
CAF DACLIMIT
TS L
OVSPOT INDEX SPNDX
CS EDRIVEX # CURRENT VALUE OF DAC
AD L
INDEX SPNDX
ADS CDUXCMD
INDEX SPNDX
LXCH EDRIVEX
CCS SPNDX
TCF DACLOOP
CAF 13,14,15
EXTEND
DRIVEDAC WOR CHAN14 # SET DAC ACTIVITY BITS
TC Q
REINIT CAF DELAY200 # ........TILT LOGIC
TS TIME5 # REINITIALIZE DAP IN 200MS
TS T5PHASE
TCF RESUME
DELAY200 DEC 16364 # 200MS
DEC -384
DACLIMIT DEC 16000
## Page 1011
DEC 384
## Page 1012
# INITIALIZATION PROGRAM FOR RCS-CSM AUTOPILOT
#
# THE FOLLOWING QUANTITIES WILL BE ZEROED AND SHOULD APPEAR IN CONSECUTIVE LOCATIONS IN MEMORY AFTER WBODY
#
# WBODY (+1) DFT TAU2
# WBODY1 (+1) DFT1 BIAS
# WBODY2 (+1) DFT2 BIAS1
# ADOT (+1) DRHO (+1) BIAS2
# ADOT1 (+1) DRHO1 (+1) ERRORX
# ADOT2 (+1) DRHO2 (+1) ERRORY
# MERRORX (+1) ATTSEC ERRORZ
# MERRORY (+1) TAU
# MERRORZ (+1) TAU1
FRESHDAP CAF ONE # RESET HOLDFLAG TO STOP AUTOMATIC
TS HOLDFLAG # STEERING AND PREPARE TO PICK UP AN
# ATTITUDE HOLD REFERENCE
REDAP TC IBNKCALL # DECODE DAPDATR1, DAPDATR2 FOR DEADBANDS
CADR S41.2 # RATES, QUADFAILS, QUAD MANAGEMENT
TC IBNKCALL # DECODE IXX, IAVG AND CONVERT
CADR S40.14 # TO AUTOPILOT GAINS
CAF NO.T5VAR # NO. LOCATIONS TO BE ZEROED MINUS 2
# NO.T5VAR MUST BE ODD *************
ZEROT5 CCS A
TS SPNDX
CAF ZERO
TS L
INDEX SPNDX
DXCH WBODY +1
CCS SPNDX
TCF ZEROT5
TS WBODY # ZERO LAST (FIRST) ONE
TC ZEROJET
CS ZERO
TS CHANTEMP # INITIALIZE MINIMUM IMPULSE CONTROL
TS CH31TEMP # INITIALIZE RHC POSITION MEMORY FOR
# MANUAL RATE MODES
CAF =.24
TS SLOPE # INITIALIZE SWITCHING LOGIC SLOPE
CAF FOUR
TS T5TIME # PHASE 0 RESETS FOR PHASE 2 INTERRUPT IN
# 60 MS. PHASE 2 RESETS FOR PHASE 1 RUPT
# IN (80MS - T5TIME(40MS)). THEREFORE
# PHASE 1 (RATEFILTER) BEGINS CYCLING 100
# MS FROM NOW AND EVERY 100MS THEREAFTER
## Page 1013
CAF ELEVEN
TS ATTKALMN # RESET TO PICK UP KALMAN FILTER GAINS
# TO INITIALIZE THE S/C ANGULAR RATES
CA CDUX
TS RHO
CA CDUY
TS RHO1
CA CDUZ
TS RHO2
CAF ZERO # RESET AUTOPILOT TO BEGIN EXECUTING
TS T5PHASE # PHASE2 OF PROGRAM
CS IMODES33 # CHECK IMU STATUS
MASK NOIMUDAP # IF BIT6 =0 IMU IN FINE ALIGN
CCS A # IF BIT6 = 1 IMU NOT READY
TCF IMUAOK
TS ATTKALMN # CANNOT USE IMU
CAF RCSINITB # PROVIDE FREE CONTROL ONLY
TCF RCSSWIT # DONT START UP RATE FILTER
# SIGNAL NO RATE FILTER
IMUAOK CAF PRIO34 # START MATRIX INITIALIZATION
TC NOVAC # BYPASS IF IMU NOT IN FINE ALIGN
EBANK= KMPAC
2CADR AMBGUPDT
CAF RCSINIT # CLEAR BIT14 -ASSUME WE HAVE A GOOD IMU
RCSSWIT TS RCSFLAGS # CLEAR BIT1 -INITIALIZE T6 PROGRAM
# SET BIT3 -INITIALIZE NEEDLES
# CLEAR BIT4 -RESET FOR FDAIDSP1
CAF T5WAIT60 # NEXT T5RUPT 60 MS FROM NOW TO ALLOW IMU
# ERROR COUNTER TO ZERO.
# (MINIMUM DELAY = 15 MS)
TS TIME5 # SINCE ATTKALMN IS +11, PROGRAM WILL THEN
TC RESUME # PICK UP THE KALMAN FILTER GAINS. RATE
# FILTER WILL BEGIN OPERATING ZOOMS FROM
# NOW
# CONSTANTS USED IN INITIALIZATION PROGRAM
NO.T5VAR DEC 35 # NO. OF LOCATIONS TO BE ZEROED
# MINUS 2...MUST BE ODD
# FOR AN EVEN NUMBER OF VARIABLES TO BE ZEROED....
# * SET NO.T5VAR EQUAL TO NUMBER OF VARIABLES MINUS 1
# * DO DXCH WBODY INSTEAD OF WBODY + 1
# * DELETE TS WBODY
=.24 DEC .24 # = SLOPE OF 0.6/SEC
RCSINIT = BIT3
RCSINITB OCT 20004
## Page 1014
T5WAIT60 DEC 16378 # = 6 CS
EBANK= KMPAC
T6ADDR 2CADR T6START
-75DEGS DEC -.41666 # -75 DEGS IN REVS * 2
ZEROJET CAF ELEVEN # ZERO BLAST2, BLAST1, BLAST, YWORD2,
+1 TS SPNDX # YWORD1,PWORD2,PWORD1,RWORD2,
CAF ZERO # AND RWORD1.
INDEX SPNDX
TS RWORD1
CCS SPNDX
TCF ZEROJET +1
CAF FOUR
TS BLAST1 +1
CAF ELEVEN
TS BLAST2 +1
CS BIT1
MASK RCSFLAGS
TS RCSFLAGS # RESET BIT1 OF RCSFLAGS TO 0
EXTEND
DCA T6ADDR
DXCH T6LOC
CAF =+14MS # ENABLE T6RUPT TO SHUT OFF JETS IN 14 MS.
TS TIME6
EXTEND
QXCH RUPTREG1
TC C13STALL
CAF BIT15
EXTEND
WOR CHAN13
TC RUPTREG1
T5PHASE2 CCS ATTKALMN # IF (+) INITIALIZE RATE ESTIMATE
TCF KALUPDT
TCF +2 # ONLY IF ATTKALMN POSITIVE
TCF +1
CA DELTATT2 # RESET FOR PHASE3 IN 20 MS
XCH TIME5 # (JET SELECTION LOGIC )
ADS T5TIME # TO COMPENSATE FOR DELAYS IN T5RUPT
CCS CDUZ
## Page 1015
TCF GIMBY # +(
TCF OKGIMB # +0
TCF GIMBY # -N
TCF OKGIMB # -0
GIMBY AD -75DEGS
EXTEND
BZMF OKGIMB
TC UPFLAG # ATTITUDE HOLD WHEN MIDDLE GIMBAL ANGLE
ADRES STIKFLAG # GREATER THAN 75 DEGREES
CAF ZERO
TS HOLDFLAG
OKGIMB CA RCSFLAGS # IF A HIGH RATE AUTO MANEUVER IS IN
MASK BIT15 # PROGRESS (BIT 15 OF RCSFLAGS SET), SET
EXTEND # ATTKALMN TO -1
BZF NOHIAUTO # OTHERWISE SET ATTKALMN TO 0.
CS ONE
NOHIAUTO TS ATTKALMN
## Page 1016
# MANUAL ROTATION COMMANDS
CS OCT01760 # RESET FORCED FIRING BITS (BITS 10 TO 5
MASK RCSFLAGS # OF RCSFLAGS) TO ZERO
TS RCSFLAGS
EXTEND
READ CHAN31
TS L
CA CH31TEMP
EXTEND
RXOR LCHAN
MASK MANROT # = OCT00077
EXTEND
BZMF NOCHANGE
LXCH A
TS CH31TEMP # SAVE CONTENTS OF CHANNEL 31 IN CH31TEMP
CA L
EXTEND
MP BIT5 # PUT BITS 6-1 OF A IN BITS 10-5 OF L
CA L
ADS RCSFLAGS # SET FORCED FIRING BITS FOR AXES WITH
# WITH CHANGES IN COMMAND. BITS 10,9 FOR
# ROLL, BITS 8,7 FOR YAW, BITS 6,5 FOR
# PITCH
CS RCSFLAGS # SET RATE DAMPING FLAGS (BITS 13,12,AND
MASK OCT16000 # 11 OF RCSFLAGS)
ADS RCSFLAGS
NOCHANGE CS CH31TEMP
MASK MANROT
EXTEND
BZMF AHFNOROT # IF NO MANUAL COMMANDS, GO TO AHFNOROT
TS HOLDFLAG # SET HOLDFLAG +
TC STICKCHK # WHEN THE RHC IS OUT OF DETENT, PMANNDX,
# YMANNDX, AND RMANNDX ARE ALL SET, BY
# MEANS OF STICKCHK, TO 0, 1, OR 2 FOR NO,
# +, OR - ROTATION RESPECTIVELY AS
# COMMANDED BY THE RHC.
#
# HOWEVER, IT IS WELL TO NOTE THAT AFTER
# THE RHC IS RETURNED TO DETENT, THE
# PROGRAM BRANCHES TO AHFNOROT AND AVOIDS
# STICKCHK SO PMANNDX, YMANNDX, AND
# RMANNDX ARE NOT RESET TO ZERO BUT RATHER
# LEFT SET TO THEIR LAST OUT OF DETENT
## Page 1017
# VALUES.
CS FLAGWRD1 # SET STIKFLAG TO INFORM STEERING
MASK STIKBIT # PROGRAMS (P20) THAT ASTRONAUT HAS
ADS FLAGWRD1 # ASSUMED ROTATIONAL CONTROL OF SPACECRAFT
CAF BIT14
TC C31BTCHK
TCF FREEFUNC
CA RCSFLAGS # EXAMINE RCSFLAGS TO SEE IF RATE FILTER
MASK BIT14 # HAS BEEN INITIALIZED
CCS A # IF SO, PROCEED WITH MANUAL RATE COMMANDS
TCF REINIT # .....TILT, RECYCLE TO INITIALIZE FILTER
CS FIVE # IF MANUAL MANEUVER IS AT HIGH RATE, SET
AD RATEINDX # ATTKALMN TO -1.
EXTEND # OTHERWISE, LEAVE ATTKALMN ALONE.
BZMF +3
CS ONE
TS ATTKALMN
CAF TWO # AUTO-HOLD MANUAL ROTATION
SETWBODY TS SPNDX
DOUBLE
TS DPNDX
INDEX SPNDX # RMANNDX = 0 NO ROTATION
CA RMANNDX # = 1 + ROTATION
EXTEND # = 2 - ROTATION
BZF NORATE # IF NO ROTATION COMMAND ON THIS AXIS,
# GO TO NORATE.
AD RATEINDX # RATEINDX = 0 0.05 DEG/SEC
TS Q # = 2 0.2 DEG/SEC
INDEX Q # = 4 0.5 DEG/SEC
CA MANTABLE -1 # = 6 2.0 DEG/SEC
EXTEND
MP BIT9 # MULTIPLY MANTABLE BY 2 TO THE -6
INDEX DPNDX # TO GET COMMANDED RATE.
DXCH WBODY # SET WBODY TO COMMANDED RATE.
CA RCSFLAGS
MASK OCT16000 # IS RATE DAMPING COMPLETED (BITS 13,12 AND
EXTEND # 11 OF RCSFLAGS ALL ZERO.) IF SO, GO TO
BZF MERUPDAT # MERUPDAT TO UPDATE CUMULATIVE ATTITUDE
# ERROR.
ZEROER CA ZERO # ZEROER ZEROS MERRORS
ZL
INDEX DPNDX
## Page 1018
DXCH MERRORX
TCF SPNDXCHK
NORATE ZL
INDEX DPNDX
DXCH WBODY # ZERO WBODY FOR THIS AXIS
CA RCSFLAGS
MASK OCT16000
EXTEND # IS RATE DAMPING COMPLETED
BZF SPNDXCHK # YES, KEEP CURRENT MERRORX GO TO SPNDXCHK
TCF ZEROER # NO, GO TO ZEROER
MERUPDAT INDEX Q # MERRORX=MERRORX+MEASURED CHANGE IN ANGLE
CS MANTABLE -1 # -COMMANDED CHANGE IN ANGLE
EXTEND # THE ADDITION OF MEASURED CHANGE IN ANGLE
MP BIT7 # HAS ALREADY BEEN DONE IN THE RATE FILTER
INDEX DPNDX # COMMANDED CHANGE IN ANGLE = WBODY TIMES
DAS MERRORX # .1SEC = MANTABLE ENTRY TIMES 2 TO THE -8
SPNDXCHK INDEX DPNDX
CA MERRORX
INDEX SPNDX
TS ERRORX # ERRORX = HIGH ORDER WORD OF MERRORX
CCS SPNDX
TCF SETWBODY
TCF JETS
OCT01760 OCT 01760 # FORCED FIRING BITS MASK
OCT01400 OCT 01400 # ROLL FORCED FIRING MASK ORDER OF
OCT00060 OCT 00060 # PITCH FORCED FIRING MASK DEFINITION
OCT00300 OCT 00300 # YAW FORCED FIRING MASK MUST BE
# PRESERVED
# FOR INDEXING
MANROT OCT 77
OCT16000 OCT 16000 # RATE DAMPING FLAGS MASK
MANTABLE DEC .0071111
DEC -.0071111
DEC .028444
DEC -0.028444
DEC .071111
DEC -.071111
DEC .284444
DEC -.284444
=+14MS DEC 23
FREEFUNC CA RCSFLAGS
EXTEND
MP BIT11 # SHIFT RIGHT 4 BITS
TS T5TEMP
## Page 1019
CS CH31TEMP
MASK T5TEMP # A= COMPLEMENT OF NEW CH 31 COMMANDS
TCF RHCMINP
T6PROGM CAF ZERO # FOR MANUAL ROTATIONS
TS ERRORX
TS ERRORY
TS ERRORZ
TCF T6PROG
## Page 1020
FREETAU DEC 0
DEC 480
DEC -480
DEC 0
DEC .2112 # FILTER GAIN FOR TRANSLATION, LEM ON
DEC .8400 # FILTER GAIN FOR TRANSLATION 2(ZETA)WN DT
DEC .2112 # FILTER GAIN FOR 2 DEGREES/SEC MANEUVERS
GAIN1 DEC .0640 # KALMAN FILTER GAINS FOR INITIALIZATION
DEC .3180 # OF ATTITUDE RATES
DEC .3452
DEC .3774
DEC .4161
DEC .4634
DEC .5223
DEC .5970
DEC .6933
DEC .8151
DEC .9342
DEC .0174 # FILTER GAIN FOR TRANSLATION, LEM ON
DEC .3600 # FILTER GAIN FOR TRANSLATION (WN)(WN)DT
DEC .0174 # FILTER GAIN FOR 2 DEGREES/SEC MANEUVERS
GAIN2 DEC .0016 # SCALED 10
DEC .0454
DEC .0545
DEC .0666
DEC .0832
DEC .1069
DEC .1422
DEC .1985
DEC .2955
DEC .4817
DEC .8683
STICKCHK TS T5TEMP
MASK THREE # INDECES FOR MANUAL ROTATION
TS PMANNDX
CA T5TEMP
EXTEND # MAN RATE 0 0 RATE (DP)
MP QUARTER # +1 +RATE (DP)
TS T5TEMP # +2 -RATE (DP)
MASK THREE # (+3) 0 RATE (DP)
TS YMANNDX
CA T5TEMP
EXTEND
MP QUARTER
TS RMANNDX
TC Q
## Page 1021
KALUPDT TS ATTKALMN # INITIALIZATION OF ATTITUDE RATES USING
# KALMAN FILTER TAKES 1.1 SEC
CA DELTATT # =1SEC - 80MS
AD T5TIME # + DELAYS
TS TIME5
TCF +3
CAF DELTATT2 # SAFETY PLAY TO ASSURE
TS TIME5 # A T5RUPT
KRESUME2 CS ZERO # RESET FOR PHASE1
TS T5PHASE # RESUME INTERRUPTED PROGRAM
TCF RESUME
FDAIDSP2 CS BIT4 # RESET FOR FDAIDSP1
MASK RCSFLAGS
TS RCSFLAGS
CS FLAGWRD0 # ON - DISPLAY ONE OF THE TOTAL ATTITUDE
MASK NEEDLBIT # ERRORS
EXTEND
BZF FDAITOTL
EXTEND
DCS ERRORX # OFF - DISPLAY AUTOPILOT FOLLOWING ERROR
DXCH AK
CS ERRORZ
TS AK2
TCF RESUME # END PHASE 1
FDAITOTL CA FLAGWRD9
MASK N2217BIT
EXTEND
BZF WRTN17 # IS N22ORN17 (BIT6 OF FLAGWRD9) = 0
# IF SO, GO TO WRTN17
WRTN22 EXTEND # OTHERWISE, CONTINUE ON TO WRTN22 AND
DCA CTHETA # GET SET TO COMPUTE TOTAL ATTITUDE
DXCH WTEMP # ERROR WRT N22 BY PICKING UP THE THREE
CA CPHI # COMPONENTS OF N22
GETAKS EXTEND # COMPUTE TOTAL ATTITUDE ERROR FOR
MSU CDUX # DISPLAY ON FDAI ERROR NEEDLES
TS AK
CA WTEMP
EXTEND
MSU CDUY
TS T5TEMP
EXTEND
## Page 1022
MP AMGB1
ADS AK
CA T5TEMP
EXTEND
MP AMGB4
TS AK1
CA T5TEMP
EXTEND
MP AMGB7
TS AK2
CA WTEMP +1
EXTEND
MSU CDUZ
TS T5TEMP
EXTEND
MP AMGB5
ADS AK1
CA T5TEMP
EXTEND
MP AMGB8
ADS AK2
TCF RESUME # END PHASE1 OF RCS DAP
WRTN17 EXTEND # GET SET TO COMPUTE TOTAL ASTRONAUT
DCA CPHIX +1 # ATTITUDE ERROR WRT N17 BY PICKING UP
DXCH WTEMP # THE THREE COMPONENTS OF N17
CA CPHIX
TCF GETAKS
## Page 1023
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