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flightgear/src/FDM/LaRCsim/c172_main.c

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// LaRCsim.cxx -- interface to the LaRCsim flight model
//
// Written by Curtis Olson, started October 1998.
//
// Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// $Id$
#include <FDM/LaRCsim/ls_cockpit.h>
#include <FDM/LaRCsim/ls_generic.h>
#include <FDM/LaRCsim/ls_interface.h>
#include <FDM/LaRCsim/ls_constants.h>
#include <FDM/LaRCsim/atmos_62.h>
/* #include <FDM/LaRCsim/ls_trim_fs.h> */
#include <FDM/LaRCsim/c172_aero.h>
#include <FDM/LaRCsim/ic.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
void do_trims(int kmax,FILE *out,InitialConditions IC)
{
int k=0,i,j;
double speed,elevator,cmcl,maxspeed;
out=fopen("trims.out","w");
speed=55;
for(j=0;j<=30;j+=10)
{
IC.flap_handle=j;
for(i=1;i<=5;i++)
{
switch(i)
{
case 1: IC.weight=1500;IC.cg=0.155;break;
case 2: IC.weight=1500;IC.cg=0.364;break;
case 3: IC.weight=1950;IC.cg=0.155;break;
case 4: IC.weight=2550;IC.cg=0.257;break;
case 5: IC.weight=2550;IC.cg=0.364;break;
}
speed=40;
if(j > 0) { maxspeed = 90; }
else { maxspeed = 170; }
while(speed <= maxspeed)
{
IC.vc=speed;
Long_control=0;Theta=0;Throttle_pct=0.0;
k=trim_long(kmax,IC);
if(Long_control <= 0)
elevator=Long_control*28;
else
elevator=Long_control*23;
if(fabs(CL) > 1E-3)
{
cmcl=cm / CL;
}
if(k < kmax)
{
fprintf(out,"%g,%g,%g,%g,%g,%d",V_calibrated_kts,Alpha*RAD_TO_DEG,Long_control,Throttle_pct,Flap_Position,k);
fprintf(out,",%g,%g,%g,%g,%g\n",CL,cm,cmcl,Weight,Cg);
/* printf("%g,%g,%g,%g,%g,%g,%g,%g,%g,%g\n",V_calibrated_kts,Alpha*RAD_TO_DEG,elevator,CL,cm,Cmo,Cma,Cmde,Mass*32.174,Dx_cg);
*/ }
else
{
printf("kmax exceeded at: %g knots, %g lbs, %g %%MAC, Flaps: %g\n",V_calibrated_kts,Weight,Cg,Flap_Position);
printf("wdot: %g, udot: %g, qdot: %g\n",W_dot_body,U_dot_body,Q_dot_body);
printf("Alpha: %g, Throttle_pct: %g, Long_control: %g\n\n",Alpha*RAD_TO_DEG,Throttle_pct,Long_control);
}
speed+=10;
}
}
}
fclose(out);
}
void find_trim_stall(int kmax,FILE *out,InitialConditions IC)
{
int k=0,i,j;
int failf;
char axis[10];
double speed,elevator,cmcl,speed_inc,lastgood;
out=fopen("trim_stall.summary","w");
speed=90;
speed_inc=10;
//failf=malloc(sizeof(int));
for(j=0;j<=30;j+=10)
{
IC.flap_handle=j;
for(i=1;i<=6;i++)
{
switch(i)
{
case 1: IC.weight=1500;IC.cg=0.155;break;
case 2: IC.weight=1500;IC.cg=0.364;break;
case 3: IC.weight=2400;IC.cg=0.155;break;
case 4: IC.weight=2400;IC.cg=0.364;break;
case 5: IC.weight=2550;IC.cg=0.257;break;
case 6: IC.weight=2550;IC.cg=0.364;break;
}
speed=90;
speed_inc=10;
while(speed_inc >= 0.5)
{
IC.vc=speed;
Long_control=0;Theta=0;Throttle_pct=0.0;
failf=trim_longfr(kmax,IC);
if(Long_control <= 0)
elevator=Long_control*28;
else
elevator=Long_control*23;
if(fabs(CL) > 1E-3)
{
cmcl=cm / CL;
}
if(failf == 0)
{
lastgood=speed;
axis[0]='\0';
//fprintf(out,"%g,%g,%g,%g,%g,%d",V_calibrated_kts,Alpha*RAD_TO_DEG,Long_control,Throttle_pct,Flap_Position,k);
//fprintf(out,",%g,%g,%g,%g,%g\n",CL,cm,cmcl,Weight,Cg);
/* printf("%g,%g,%g,%g,%g,%g,%g,%g,%g,%g\n",V_calibrated_kts,Alpha*RAD_TO_DEG,elevator,CL,cm,Cmo,Cma,Cmde,Mass*32.174,Dx_cg);
*/ }
else
{
printf("trim failed at: %g knots, %g lbs, %g %%MAC, Flaps: %g\n",V_calibrated_kts,Weight,Cg,Flap_Position);
printf("wdot: %g, udot: %g, qdot: %g\n",W_dot_body,U_dot_body,Q_dot_body);
printf("Alpha: %g, Throttle_pct: %g, Long_control: %g\n\n",Alpha*RAD_TO_DEG,Throttle_pct,Long_control);
printf("Speed increment: %g\n",speed_inc);
speed+=speed_inc;
speed_inc/=2;
}
speed-=speed_inc;
}
printf("failf %d\n",failf);
if(failf == 1)
strcpy(axis,"lift");
else if(failf == 2)
strcpy(axis,"thrust");
else if(failf == 3)
strcpy(axis,"pitch");
fprintf(out,"Last good speed: %g, Flaps: %g, Weight: %g, CG: %g, failed axis: %s\n",lastgood,Flap_handle,Weight,Cg,axis);
}
}
fclose(out);
//free(failf);
}
// Initialize the LaRCsim flight model, dt is the time increment for
// each subsequent iteration through the EOM
int fgLaRCsimInit(double dt) {
ls_toplevel_init(dt);
return(1);
}
// Run an iteration of the EOM (equations of motion)
int main(int argc, char *argv[]) {
double save_alt = 0.0;
int multiloop=1,k=0,i,j;
double time=0,elev_trim,elev_trim_save,elevator,speed,cmcl;
FILE *out;
double hgain,hdiffgain,herr,herrprev,herr_diff,htarget;
double lastVt,vtdots,vtdott;
InitialConditions IC;
SCALAR *control[7];
SCALAR *state[7];
float old_state,effectiveness,tol,delta_state,lctrim;
if(argc < 6)
{
printf("Need args: $c172 speed alt alpha elev throttle\n");
exit(1);
}
initIC(&IC);
IC.latitude=47.5299892; //BFI
IC.longitude=122.3019561;
Runway_altitude = 18.0;
IC.altitude=strtod(argv[2],NULL);
IC.vc=strtod(argv[1],NULL);
IC.alpha=0;
IC.beta=0;
IC.gamma=strtod(argv[3],NULL);
IC.use_gamma_tmg=1;
IC.phi=0;
IC.psi=10;
IC.weight=2300;
IC.cg=0.25;
IC.flap_handle=0;
IC.long_control=strtod(argv[4],NULL);
IC.rudder_pedal=0;
printf("IC.vc: %g\n",IC.vc);
ls_ForceAltitude(IC.altitude);
fgLaRCsimInit(0.01);
printf("\nLong_control: %g\n\n",Long_control);
IC.altitude=1000;
setIC(IC);
ls_loop(0.0,-1);
IC.flap_handle=10;
setIC(IC);
ls_loop(0.0,-1);
IC.flap_handle=20;
setIC(IC);
ls_loop(0.0,-1);
IC.flap_handle=30;
setIC(IC);
ls_loop(0.0,-1);
/* find_trim_stall(200,out,IC);
IC.vc=120;
IC.altitude=8000;
IC.weight=2300;
IC.cg=0.25;
IC.flap_handle=0;
setIC(IC);
printIC(IC);
k=trim_long(100,IC);
printf("Flap_handle: %g, Flap_Position: %g\n",Flap_handle,Flap_Position);
printf("k: %d, %g knots, %g lbs, %g %%MAC\n",k,V_calibrated_kts,Weight,Cg);
printf("wdot: %g, udot: %g, qdot: %g\n",W_dot_body,U_dot_body,Q_dot_body);
printf("Alpha: %g, Throttle_pct: %g, Long_control: %g\n\n",Alpha,Throttle_pct,Long_control);
printf("Cme: %g, elevator: %g, Cmde: %g\n",elevator*Cmde,elevator,Cmde);
IC.cg=0.155;
setIC(IC);
k=trim_long(100,IC);
printf("Flap_handle: %g, Flap_Position: %g\n",Flap_handle,Flap_Position);
printf("k: %d, %g knots, %g lbs, %g %%MAC\n",k,V_calibrated_kts,Weight,Cg);
printf("wdot: %g, udot: %g, qdot: %g\n",W_dot_body,U_dot_body,Q_dot_body);
printf("Alpha: %g, Throttle_pct: %g, Long_control: %g\n\n",Alpha,Throttle_pct,Long_control);
printf("Cme: %g, elevator: %g, Cmde: %g\n",elevator*Cmde,elevator,Cmde);
IC.cg=0.364;
setIC(IC);
k=trim_long(100,IC);
printf("Flap_handle: %g, Flap_Position: %g\n",Flap_handle,Flap_Position);
printf("k: %d, %g knots, %g lbs, %g %%MAC\n",k,V_calibrated_kts,Weight,Cg);
printf("wdot: %g, udot: %g, qdot: %g\n",W_dot_body,U_dot_body,Q_dot_body);
printf("Alpha: %g, Throttle_pct: %g, Long_control: %g\n\n",Alpha,Throttle_pct,Long_control);
printf("Cme: %g, elevator: %g, Cmde: %g\n",elevator*Cmde,elevator,Cmde);
*/
/* do_trims(400,out,IC); */
/* ls_loop(0.0,-1);
control[1]=&IC.long_control;
control[2]=&IC.throttle;
control[3]=&IC.alpha;
control[4]=&IC.beta;
control[5]=&IC.phi;
control[6]=&IC.lat_control;
state[1]=&Q_dot_body;state[2]=&U_dot_body;state[3]=&W_dot_body;
state[4]=&R_dot_body;state[5]=&V_dot_body;state[6]=&P_dot_body;
for(i=1;i<=6;i++)
{
old_state=*state[i];
tol=1E-4;
for(j=1;j<=6;j++)
{
*control[j]+=0.1;
setIC(IC);
ls_loop(0.0,-1);
delta_state=*state[i]-old_state;
effectiveness=(delta_state)/ 0.1;
if(delta_state < tol)
effectiveness = 0;
printf("%8.4f,",delta_state);
*control[j]-=0.1;
}
printf("\n");
setIC(IC);
ls_loop(0.0,-1);
} */
return 1;
}
/*
void do_stick_pull(int kmax, SCALAR tmax,FILE *out,InitialConditions IC)
{
SCALAR htarget,hgain,hdiffgain,herr,herr_diff,herrprev;
SCALAR theta_trim,elev_trim,time;
int k;
k=trim_long(kmax,IC);
printf("Trim:\n\tAlpha: %10.6f, elev: %10.6f, Throttle: %10.6f\n\twdot: %10.6f, qdot: %10.6f, udot: %10.6f\n",Alpha*RAD_TO_DEG,Long_control,Throttle_pct,W_dot_body,U_dot_body,Q_dot_body);
htarget=0;
hgain=1;
hdiffgain=1;
elev_trim=Long_control;
out=fopen("stick_pull.out","w");
herr=Q_body-htarget;
//fly steady-level for 2 seconds, well, zero pitch rate anyway
while(time < 2.0)
{
herrprev=herr;
ls_update(1);
herr=Q_body-htarget;
herr_diff=herr-herrprev;
Long_control=elev_trim+(hgain*herr + hdiffgain*herr_diff);
time+=0.01;
//printf("Time: %7.4f, Alt: %7.4f, Alpha: %7.4f, pelev: %7.4f, qdot: %7.4f, udot: %7.4f, Phi: %7.4f, Psi: %7.4f\n",time,Altitude,Alpha*RAD_TO_DEG,Long_control*100,Q_body*RAD_TO_DEG,U_dot_body,Phi,Psi);
//printf("Mcg: %7.4f, Mrp: %7.4f, Maero: %7.4f, Meng: %7.4f, Mgear: %7.4f, Dx_cg: %7.4f, Dz_cg: %7.4f\n\n",M_m_cg,M_m_rp,M_m_aero,M_m_engine,M_m_gear,Dx_cg,Dz_cg);
fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,",time,V_true_kts,Theta*RAD_TO_DEG,Alpha*RAD_TO_DEG,Q_body*RAD_TO_DEG,Alpha_dot*RAD_TO_DEG,Q_dot_body*RAD_TO_DEG,Throttle_pct,elevator*RAD_TO_DEG);
fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f\n",CL,CLwbh,cm,cd,Altitude);
}
//begin untrimmed climb at theta_trim + 2 degrees
hgain=4;
hdiffgain=2;
theta_trim=Theta;
htarget=theta_trim;
herr=Theta-htarget;
while(time < tmax)
{
//ramp in the target theta
if(htarget < (theta_trim + 2*DEG_TO_RAD))
{
htarget+= 0.01*DEG_TO_RAD;
}
herrprev=herr;
ls_update(1);
herr=Theta-htarget;
herr_diff=herr-herrprev;
Long_control=elev_trim+(hgain*herr + hdiffgain*herr_diff);
time+=0.01;
//printf("Time: %7.4f, Alt: %7.4f, Alpha: %7.4f, pelev: %7.4f, qdot: %7.4f, udot: %7.4f, Phi: %7.4f, Psi: %7.4f\n",time,Altitude,Alpha*RAD_TO_DEG,Long_control*100,Q_body*RAD_TO_DEG,U_dot_body,Phi,Psi);
//printf("Mcg: %7.4f, Mrp: %7.4f, Maero: %7.4f, Meng: %7.4f, Mgear: %7.4f, Dx_cg: %7.4f, Dz_cg: %7.4f\n\n",M_m_cg,M_m_rp,M_m_aero,M_m_engine,M_m_gear,Dx_cg,Dz_cg);
fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,",time,V_true_kts,Theta*RAD_TO_DEG,Alpha*RAD_TO_DEG,Q_body*RAD_TO_DEG,Alpha_dot*RAD_TO_DEG,Q_dot_body*RAD_TO_DEG,Throttle_pct,elevator*RAD_TO_DEG);
fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f\n",CL,CLwbh,cm,cd,Altitude);
}
printf("%g,%g\n",theta_trim*RAD_TO_DEG,htarget*RAD_TO_DEG);
fclose(out);
}
void do_takeoff(FILE *out)
{
SCALAR htarget,hgain,hdiffgain,elev_trim,elev_trim_save,herr;
SCALAR time,herrprev,herr_diff;
htarget=0;
hgain=1;
hdiffgain=1;
elev_trim=Long_control;
elev_trim_save=elev_trim;
out=fopen("takeoff.out","w");
herr=Q_body-htarget;
// attempt to maintain zero pitch rate during the roll
while((V_calibrated_kts < 61) && (time < 30.0))
{
// herrprev=herr
ls_update(1);
// herr=Q_body-htarget;
// herr_diff=herr-herrprev;
// Long_control=elev_trim+(hgain*herr + hdiffgain*herr_diff);
time+=0.01;
printf("Time: %7.4f, Vc: %7.4f, Alpha: %7.4f, pelev: %7.4f, qdot: %7.4f, udot: %7.4f, U: %7.4f, W: %7.4f\n",time,V_calibrated_kts,Alpha*RAD_TO_DEG,Long_control*100,Q_body*RAD_TO_DEG,U_dot_body,U_body,W_body);
// printf("Mcg: %7.4f, Mrp: %7.4f, Maero: %7.4f, Meng: %7.4f, Mgear: %7.4f, Dx_cg: %7.4f, Dz_cg: %7.4f\n\n",M_m_cg,M_m_rp,M_m_aero,M_m_engine,M_m_gear,Dx_cg,Dz_cg);
// fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,",time,V_calibrated_kts,Theta*RAD_TO_DEG,Alpha*RAD_TO_DEG,Q_body*RAD_TO_DEG,Alpha_dot*RAD_TO_DEG,Q_dot_body*RAD_TO_DEG,Throttle_pct,elevator*RAD_TO_DEG);
fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f\n",CL,CLwbh,cm,cd,Altitude);
}
//At Vr, ramp in 10% nose up elevator in 0.5 seconds
elev_trim_save=0;
printf("At Vr, rotate...\n");
while((Q_body < 3.0*RAD_TO_DEG) && (time < 30.0))
{
Long_control-=0.01;
ls_update(1);
printf("Time: %7.4f, Vc: %7.4f, Alpha: %7.4f, pelev: %7.4f, q: %7.4f, cm: %7.4f, U: %7.4f, W: %7.4f\n",time,V_calibrated_kts,Alpha*RAD_TO_DEG,Long_control*100,Q_body*RAD_TO_DEG,cm,U_body,W_body);
fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,",time,V_calibrated_kts,Theta*RAD_TO_DEG,Alpha*RAD_TO_DEG,Q_body*RAD_TO_DEG,Alpha_dot*RAD_TO_DEG,Q_dot_body*RAD_TO_DEG,Throttle_pct,elevator*RAD_TO_DEG);
fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f\n",CL,CLwbh,cm,cd,Altitude);
time +=0.01;
}
//Maintain 15 degrees theta for the climbout
htarget=15*DEG_TO_RAD;
herr=Theta-htarget;
hgain=10;
hdiffgain=1;
elev_trim=Long_control;
while(time < 30.0)
{
herrprev=herr;
ls_update(1);
herr=Theta-htarget;
herr_diff=herr-herrprev;
Long_control=elev_trim+(hgain*herr + hdiffgain*herr_diff);
time+=0.01;
printf("Time: %7.4f, Alt: %7.4f, Speed: %7.4f, Theta: %7.4f\n",time,Altitude,V_calibrated_kts,Theta*RAD_TO_DEG);
fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,%20.8f,",time,V_calibrated_kts,Theta*RAD_TO_DEG,Alpha*RAD_TO_DEG,Q_body*RAD_TO_DEG,Alpha_dot*RAD_TO_DEG,Q_dot_body*RAD_TO_DEG,Throttle_pct,elevator*RAD_TO_DEG);
fprintf(out,"%20.8f,%20.8f,%20.8f,%20.8f,%20.8f\n",CL,CLwbh,cm,cd,Altitude);
}
fclose(out);
printf("Speed: %7.4f, Alt: %7.4f, Alpha: %7.4f, pelev: %7.4f, q: %7.4f, udot: %7.4f\n",V_true_kts,Altitude,Alpha*RAD_TO_DEG,Long_control,Q_body*RAD_TO_DEG,U_dot_body);
printf("F_down_total: %7.4f, F_Z_aero: %7.4f, F_X: %7.4f, M_m_cg: %7.4f\n\n",F_down+Mass*Gravity,F_Z_aero,F_X,M_m_cg);
}
*/
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