Revision 07d422a97efd13e2c9cc89135ae2b9c9c982136f authored by Mike Stewart on 07 August 2019, 06:38:15 UTC, committed by Mike Stewart on 07 August 2019, 06:38:15 UTC
1 parent 047a9d2
GIMBAL_LOCK_AVOIDANCE.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: GIMBAL_LOCK_AVOIDANCE.agc
## Purpose: Part of the source code for Comanche, build 055.
## It is part of the source code for the Command Module's (CM)
## Apollo Guidance Computer (AGC), Apollo 11.
## Assembler: yaYUL
## Reference: pp. 412-413
## Contact: Onno Hommes <ohommes@cmu.edu>.
## Website: www.ibiblio.org/apollo.
## Mod history: 05/07/09 OH Transcription Batch 1 Assignment
## 2016-12-10 RSB Proofed comments with octopus/ProoferComments
## and fixed the errors found.
##
## The contents of the "Comanche055" files, in general, are transcribed
## from scanned documents.
##
## Assemble revision 055 of AGC program Comanche by NASA
## 2021113-051. April 1, 1969.
##
## This AGC program shall also be referred to as Colossus 2A
##
## Prepared by
## Massachusetts Institute of Technology
## 75 Cambridge Parkway
## Cambridge, Massachusetts
##
## under NASA contract NAS 9-4065.
##
## Refer directly to the online document mentioned above for further information.
## Please report any errors to info@sandroid.org.
## Page 412
BANK 15
SETLOC KALCMON1
BANK
EBANK= BCDU
# DETECTING GIMBAL LOCK
LOCSKIRT EQUALS WCALC
WCALC LXC,1 DLOAD*
RATEINDX
ARATE,1
SR4 CALL # COMPUTE THE INCREMENTAL ROTATION MATRIX
DELCOMP # DEL CORRESPONDING TO A 1 SEC ROTATION
# ABOUT COF
DLOAD* VXSC
ARATE,1
COF
MXV
QUADROT
STODL BRATE
AM
DMP DDV*
ANGLTIME
ARATE,1
SR
5
STOVL TM
BRATE
VXSC
BIASCALE
STORE BIASTEMP # ATTITUDE ERROR BIAS TO PREVENT OVERSHOOT
# IN SYSTEM
SETGO # STATE SWITCH CALCMAN2 (43D)
CALCMAN2 # 0(OFF) = BYPASS STARTING PROCEDURE
NEWANGL +1 # 1(ON) = START MANEUVER
ARATE 2DEC .0022222222 # = .05 DEG/SEC
2DEC .0088888889 # = .2 DEG/SEC
2DEC .0222222222 # = .5 DEG/SEC
2DEC .0888888889 # = 2 DEG/SEC $22.5 DEG/SEC
ANGLTIME 2DEC .000190735 # = 100B - 19
# MANEUVER ANGLE TO MANEUVER TIME
QUADROT 2DEC .1 # ROTATION MATRIX FROM S/C AXES TO CONTROL
## Page 413
2DEC 0 # AXES (X ROT = -7.25 DEG)
2DEC 0
2DEC 0
2DEC .099200 # =(.1)COS7.25
2DEC -.012620 # =-(.1)SIN7.25
2DEC 0
2DEC .012620 # (.1)SIN7.25
2DEC .099200 # (.1)COS7.25
BIASCALE 2DEC .0002543132 # = (450/180)(1/0.6)(1/16384)
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