From 396678e31391c9d2a91e6c305bcc23f298133cdc Mon Sep 17 00:00:00 2001 From: "Casper V. Kristensen" Date: Fri, 8 Feb 2019 22:17:19 +0100 Subject: [PATCH] Improve ascend guidance. --- launch.ks | 83 +++++++++++++++++++++++++++++++++-------------------- lib/util.ks | 14 ++++++++- 2 files changed, 65 insertions(+), 32 deletions(-) diff --git a/launch.ks b/launch.ks index 444ebc6..63c5d13 100644 --- a/launch.ks +++ b/launch.ks @@ -15,21 +15,23 @@ function launch { parameter pitchover_tilt is 20. // how many degrees to tilt at pitchover maneuver parameter pitchover_altitude is 1000. // perform pitchover at this altitude parameter pitchover_velocity is 100. // or this velocity + + parameter auto_stage is true. + parameter auto_deploy_solar_panels is true. + parameter auto_deploy_fairings is true. + parameter auto_extend_antennas is true. + - - print "========= LAUNCHING =========". + print "================ ASCEND GUIDANCE =================". print "Target orbital altitude: " + target_orbit_altitude + "m". print "Target orbital inclination: " + target_orbit_inclination + "°". print "Pitchover tilt: " + pitchover_tilt + "°". print "Pitchover at: " + pitchover_altitude + "m or " + pitchover_velocity + " m/s". print " ". - - - // LAUNCH AZIMUTH - + // Since the "center" of an orbit must be at the center of gravity of the body, the latitude of the launch site establishes the minimum absolute orbital inclination. // KSC is almost on the equator, so we're going to always round the latitude towards zero to allow any inclination from KSC and accept the inaccuracies it may introduce. - local launch_site_latitude is round_towards_zero(LATITUDE). + local launch_site_latitude is int(LATITUDE). local target_orbit_inclination is max(target_orbit_inclination, launch_site_latitude). // Calculate the launch azimuth; the compass heading we head for when launching to achieve orbit of desired inclination @@ -45,52 +47,71 @@ function launch { print "Available orbital inclination: " + target_orbit_inclination + "°". print "Launch azimuth: " + round(launch_azimuth, 3) + "°". print "Launch southwards: " + southwards. - - - print "--- VERTICAL CLIMB ---". + print " ". + print "Auto-staging: " + auto_stage. + print "Auto-deploy solar panels: " + auto_deploy_solar_panels. + print "Auto-deploy fairings: " + auto_deploy_fairings. + print "Auto-extend antennas: " + auto_extend_antennas. + print " ". + + + // LAUNCH + SAS off. RCS on. set NAVMODE to "SURFACE". lock STEERING to heading(launch_azimuth, 90). // roll to launch azimuth lock THROTTLE to 1.0. - - - // LAUNCH - - // Enable auto-staging - when should_stage() then { + + when auto_stage and should_stage() then { stage_when_ready(). wait 0.5. return true. // preserve trigger } - // Once a certain altitude (or velocity) is reached, a slight turn is made, called the pitchover maneuver + print "----------------- VERTICAL CLIMB -----------------". + + print "Waiting for pitchover altitude or velocity". wait until ALTITUDE > pitchover_altitude or VELOCITY:surface:mag > pitchover_velocity. - print "--- PITCHOVER ---". + print "------------------- PITCHOVER --------------------". + // Once a certain altitude or velocity is reached, a slight turn is made, called the pitchover maneuver lock STEERING to heading(launch_azimuth, 90-pitchover_tilt). - - wait until actual_prograde_pitch() > pitchover_tilt. // wait until the prograde "catches up" to our tilted heading + + print "Waiting for prograde vector to catch up". + wait until actual_prograde_pitch() > pitchover_tilt. - print "--- GRAVITY TURN ---". + print "------------------ GRAVITY TURN ------------------". // TODO: the angle of the launch azimuth will not account for the fact that our compass will change as we move north/south. lock STEERING to heading(launch_azimuth, 90-actual_prograde_pitch()). // Follow prograde pitch to get 0 deg angle of attack, but force compass heading at launch azimuth. - + + print "Waiting for apoapsis to match target altitude". wait until APOAPSIS > target_orbit_altitude. lock THROTTLE TO 0. - print "--- CIRCULARIZE ---". - print "Waiting for ship to leave the atmosphere..". - wait until SHIP:dynamicpressure = 0. // don't create maneuver node until we are out of the atmosphere - otherwise the apoapsis altitude and eta will change due to drag + print "------------------ CIRCULARIZE -------------------". + // Don't create maneuver node until we are out of the atmosphere; otherwise the apoapsis' altitude and eta will change due to drag + print "Waiting for ship to leave the atmosphere". + warp_for(atmosphere_exit_eta()). // we'll lose some velocity due to drag, so the warp will exit a few seconds before we actually exit the atmosphere + wait until SHIP:dynamicpressure = 0. // that's why we have this check as well + + if auto_deploy_fairings { + deploy_fairings(). + wait 3. // wait for fairings to clear the vessel + } + if auto_deploy_solar_panels { + print "Deploying solar panels". + PANELS on. + } + if auto_extend_antennas { + extend_antennas(). + } - print "Deploying solar panels". - PANELS on. - - // Create maneuver node that will circularize the orbit. + // Create maneuver node that will circularize the orbit. TODO: create circulize()-function in lib/maneuvers.ks instead // NOTE: Potential errors in the inclination are not fixed, since we are most likely going to change our orbit, which will make the inclination change cheaper later on. local node is NODE(TIME:SECONDS + ETA:APOAPSIS, 0, 0, 0). @@ -102,7 +123,7 @@ function launch { execute_node(). - print "========= LAUNCH SEQUENCE COMPLETE =========". + print "------------ LAUNCH SEQUENCE COMPLETE ------------". unlock_control(). } @@ -126,4 +147,4 @@ function calculate_launch_azimuth { } -launch(100_000, 0). +launch(100_000, 45). diff --git a/lib/util.ks b/lib/util.ks index 769bf25..1e7e6c1 100644 --- a/lib/util.ks +++ b/lib/util.ks @@ -1,8 +1,20 @@ @LAZYGLOBAL OFF. -function round_towards_zero { +function int { + // + // Truncate or round towards zero. + // parameter n. if n < 0 return ceiling(n). return floor(n). } + + +function atmosphere_exit_eta { + // + // Return the number of seconds until the vessel exists the atmosphere. + // + // the vdot gives us the magnitude of the orbital velocity vector in the UP direction because UP is a unit vector + return (BODY:atm:height - ALTITUDE) / vdot(velocity:orbit, UP:vector). +}