annabunches/kOS
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Clean up and improve node execution code.

Browse Source
This commit is contained in:
Anna Rose 2021-08-03 20:35:50 -04:00
parent 935c6cf671
commit cadd3404b9
3 changed files with 89 additions and 117 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
init/rocket.ks
View File

@ -51,6 +51,9 @@ makeButton(row, "NODE", {
if HASNODE { if HASNODE {
set nodeDV:TEXT to NEXTNODE:DELTAV:MAG:ToString. set nodeDV:TEXT to NEXTNODE:DELTAV:MAG:ToString.
set nodeBT:TEXT to BurnTime(NEXTNODE:DELTAV:MAG):ToString. set nodeBT:TEXT to BurnTime(NEXTNODE:DELTAV:MAG):ToString.
} else {
set nodeDV:TEXT to "No Node".
set nodeBT:TEXT to "No Node".
} }
stk:ShowOnly(panes["node"]). stk:ShowOnly(panes["node"]).
}). }).

105
lib/node.ks
View File

@ -1,8 +1,14 @@
runoncepath("lib/navigation").
runoncepath("lib/throttle").
function ExecNode { function ExecNode {
if not HASNODE {
print "No node to execute.".
return.
}
SAS off. SAS off.
// begin the burn at leadT seconds before the node.
local leadT is BurnTime(NEXTNODE:DELTAV:MAG / 2).
local t is BurnTime(NEXTNODE:DELTAV:MAG). local t is BurnTime(NEXTNODE:DELTAV:MAG).
print "Adjusting heading". print "Adjusting heading".
@ -10,30 +16,91 @@ function ExecNode {
wait until VAng(SHIP:FACING:FOREVECTOR, STEERINGMANAGER:TARGET:FOREVECTOR) <= 0.1. wait until VAng(SHIP:FACING:FOREVECTOR, STEERINGMANAGER:TARGET:FOREVECTOR) <= 0.1.
print "Warping to node.". print "Warping to node.".
KUNIVERSE:TIMEWARP:WarpTo(NEXTNODE:TIME - (t/2) - 5). KUNIVERSE:TIMEWARP:WarpTo(NEXTNODE:TIME - leadT - 5).
wait until NEXTNODE:ETA <= (t/2). wait until NEXTNODE:ETA <= leadT.
print "Executing burn.". print "Executing burn.".
local dvMin is NEXTNODE:DELTAV:MAG. local dvMin is NEXTNODE:DELTAV:MAG.
lock THROTTLE to 1.0. lock THROTTLE to 1.0.
wait t.
// Execute the burn, throttling down by half every time we're lock THROTTLE to 0.0.
// consuming more than 25% of our dV in one update.
local droppedOnce is false.
until NEXTNODE:DELTAV:MAG <= 0.25 or (dVMin < NEXTNODE:DELTAV:MAG and droppedOnce) {
if NEXTNODE:DELTAV:MAG > dVMin {
set droppedOnce to true.
} else {
set dvMin to NEXTNODE:DELTAV:MAG.
set droppedOnce to false.
}
wait 0.01.
}
unlock THROTTLE. unlock THROTTLE.
unlock STEERING. unlock STEERING.
SAS on. SAS on.
print "Node execution complete.". print "Node execution complete.".
} }
// Calculate the time required to burn a given dV.
// Assumes a perfectly spherical Kerbal in a vacuum.
function BurnTime {
parameter totaldV, m is SHIP:MASS, s is STAGE:NUMBER.
local totalT is 0.0.
until totaldV <= 0 {
local F is stageThrust().
local Isp is stageISP().
local dV is min(totaldV, SHIP:StageDeltaV(s):VACUUM).
local t is calcBurnTime(dV, m, Isp, F).
print "DEBUG: " + dV + " m/s^2 in stage " + s + ", in " + t + " seconds.".
set totaldV to totaldV - dV.
set s to s - 1.
set totalT to totalT + t.
}
return totalT.
}
// Convenience function to wrap the actual calculation for burn time.
function calcBurnTime {
parameter dV, m, Isp, F.
if F = 0 {
print "WARNING: Tried to calculate burn time with a thrust of 0. Returning 0. Your calculations are probably wrong.".
return 0.
}
local g0 is CONSTANT:G0.
return g0 * m * Isp * (1 - CONSTANT():E^(-dV/(g0*Isp))) / F.
}
// Calculate the ISP for a given stage.
// Defaults to current stage. Assumes your ship is designed so that
// engines are discarded immediately when they flame out.
function stageISP {
parameter s is STAGE:NUMBER.
local en is list().
list ENGINES in en.
local ispSum is 0.
local eCount is 0.
for e in en {
if e:STAGE >= s and e:DECOUPLEDIN < s {
set ispSum to ispSum + e:ISP.
set eCount to eCount + 1.
}
}
if eCount = 0 { return 0. }
return ispSum / eCount.
}
// Calculates the total thrust for the given stage, in kN.
// Defaults to current stage. Assumes your ship is designed so that
// engines are discarded immediately when they flame out.
function stageThrust {
parameter s is STAGE:NUMBER.
local en is list().
list ENGINES in en.
local sum is 0.
for e in en {
if e:STAGE >= s and e:DECOUPLEDIN < s {
set sum to sum + e:POSSIBLETHRUST.
}
}
return sum.
}

98
lib/throttle.ks
View File

@ -19,101 +19,3 @@ function TWR {
local t is THROTTLE * SHIP:AVAILABLETHRUST. local t is THROTTLE * SHIP:AVAILABLETHRUST.
return t/(m*G). return t/(m*G).
} }
// Calculate the time required to burn a given dV at a given altitude.
// Must be called while in the same SOI as the burn itself.
// Assumes a perfectly spherical Kerbal in a vacuum.
function BurnTime {
parameter dV, m is SHIP:MASS, s is STAGE:NUMBER.
local f is stageThrust(). // Engine Thrust (kg * m/s²)
local Isp is stageISP(). // Engine ISP (s)
local dVs is SHIP:StageDeltaV(s):VACUUM.
if dV > dVs {
// TODO: not 100% this is needed vs using DeltaV:DURATION.
// Docs suggest DeltaV:DURATION is not entirely reliable, however.
// For now we're logging both values for comparison.
local t is burnTimeCalc(dVs, m, Isp, f).
// debug
print "Computed stage burn time = " + t.
print "KSC-estimated stage burn time = " + SHIP:StageDeltaV(s):DURATION.
// end debug
local parts is list().
for part in parts {
if part:DECOUPLEDIN = s - 1 {
set m to m - part:MASS.
}
}
return t + BurnTime(dV - SHIP:STAGEDELTAV(s):VACUUM, m, s - 1).
}
// debug
local t is burnTimeCalc(dV, m, Isp, f).
print "Burn time in last utilized stage = " + t.
// end debug
return t.
}
// Convenience function to wrap the actual calculation for burn time.
function burnTimeCalc {
parameter dV, m, Isp, f.
if f = 0 {
print "WARNING: Tried to calculate burn time with a thrust of 0. Returning 0. Your calculations are probably wrong.".
return 0.
}
// TODO: this formula differs from the following:
// t = ((M0 - Mf) * Isp * G) / f
// which is suggested at https://www.reddit.com/r/Kos/comments/lev9pw/getting_burntime_from_next_stage/gmig0hl/?context=8&depth=9
// are they equivalent? Is one better than the other? This one doesn't require
// knowing final mass, which is nice.
local g0 is CONSTANT:G0.
return g0 * m * Isp * (1 - CONSTANT():E^(-dV/(g0*Isp))) / f.
}
// Calculate the ISP for a given stage.
// Defaults to current stage. Assumes your ship is designed so that
// engines are discarded immediately when they flame out.
function stageISP {
parameter s is STAGE:NUMBER.
local en is list().
list ENGINES in en.
local ispSum is 0.
local eCount is 0.
for e in en {
if e:STAGE = s or e:STAGE > s and e:DECOUPLEDIN < s {
set ispSum to ispSum + e:ISP.
set eCount to eCount + 1.
}
}
if eCount = 0 { return 0. }
return ispSum / eCount.
}
// Calculates the total thrust for the given stage, in kN.
// Defaults to current stage. Assumes your ship is designed so that
// engines are discarded immediately when they flame out.
function stageThrust {
parameter s is STAGE:NUMBER.
local en is list().
list ENGINES in en.
local sum is 0.
for e in en {
if e:STAGE = s or e:STAGE > s and e:DECOUPLEDIN < s {
set sum to sum + e:POSSIBLETHRUST.
}
}
return sum.
}