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Improvements to Tony's c172 model.

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curt 1999-07-31 04:57:35 +00:00
parent aa68d067d0
commit 0bb22cd0a7
5 changed files with 132 additions and 99 deletions
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152
src/FDM/LaRCsim/c172_aero.c
View file

@ -88,6 +88,8 @@
#include "ls_cockpit.h"
#include "ls_constants.h"
#include "ls_types.h"
#include "c172_aero.h"
#include <math.h>
#include <stdio.h>
@ -144,84 +146,55 @@ void aero( SCALAR dt, int Initialize ) {
static SCALAR trim_inc = 0.0002;
SCALAR long_trim;
SCALAR elevator, aileron, rudder;
static SCALAR alpha_ind[NCL]={-0.087,0,0.175,0.209,0.24,0.262,0.278,0.303,0.314,0.332,0.367};
static SCALAR CLtable[NCL]={-0.14,0.31,1.21,1.376,1.51249,1.591,1.63,1.60878,1.53712,1.376,1.142};
/*Note that CLo,Cdo,Cmo will likely change with flap setting so
/*Note that CLo,Cdo,Cmo will likely change with flap setting so
they may not be declared static in the future */
static SCALAR CLadot=1.7;
static SCALAR CLq=3.9;
static SCALAR CLde=0.43;
static SCALAR CLo=0;
static SCALAR Cdo=0.031;
static SCALAR Cda=0.13; /*Not used*/
static SCALAR Cdde=0.06;
static SCALAR Cma=-0.89;
static SCALAR Cmadot=-5.2;
static SCALAR Cmq=-12.4;
static SCALAR Cmo=-0.062;
static SCALAR Cmde=-1.28;
static SCALAR Clbeta=-0.089;
static SCALAR Clp=-0.47;
static SCALAR Clr=0.096;
static SCALAR Clda=-0.178;
static SCALAR Cldr=0.0147;
static SCALAR Cnbeta=0.065;
static SCALAR Cnp=-0.03;
static SCALAR Cnr=-0.099;
static SCALAR Cnda=-0.053;
static SCALAR Cndr=-0.0657;
static SCALAR Cybeta=-0.31;
static SCALAR Cyp=-0.037;
static SCALAR Cyr=0.21;
static SCALAR Cyda=0.0;
static SCALAR Cydr=0.187;
/*nondimensionalization quantities*/
/*units here are ft and lbs */
static SCALAR cbar=4.9; /*mean aero chord ft*/
static SCALAR b=35.8; /*wing span ft */
static SCALAR Sw=174; /*wing planform surface area ft^2*/
static SCALAR rPiARe=0.054; /*reciprocal of Pi*AR*e*/
SCALAR W=Mass/INVG;
SCALAR CLwbh,CL,cm,cd,cn,cy,croll,cbar_2V,b_2V,qS,qScbar,qSb,ps,rs;
SCALAR F_X_wind,F_Y_wind,F_Z_wind,W_X,W_Y,W_Z;
if (Initialize != 0)
if (Initialize != 0)
{
CLadot=1.7;
CLq=3.9;
CLde=0.43;
CLo=0;
Cdo=0.031;
Cda=0.13; /*Not used*/
Cdde=0.06;
Cma=-0.89;
Cmadot=-5.2;
Cmq=-12.4;
Cmo=-0.062;
Cmde=-1.28;
Clbeta=-0.089;
Clp=-0.47;
Clr=0.096;
Clda=-0.178;
Cldr=0.0147;
Cnbeta=0.065;
Cnp=-0.03;
Cnr=-0.099;
Cnda=-0.053;
Cndr=-0.0657;
Cybeta=-0.31;
Cyp=-0.037;
Cyr=0.21;
Cyda=0.0;
Cydr=0.187;
/*nondimensionalization quantities*/
/*units here are ft and lbs */
cbar=4.9; /*mean aero chord ft*/
b=35.8; /*wing span ft */
Sw=174; /*wing planform surface area ft^2*/
rPiARe=0.054; /*reciprocal of Pi*AR*e*/
}
/*
LaRCsim uses:
@ -233,11 +206,12 @@ void aero( SCALAR dt, int Initialize ) {
aileron > 0 => right wing up
rudder > 0 => ANL
*/
long_trim=0;
if(Aft_trim) long_trim = long_trim - trim_inc;
if(Fwd_trim) long_trim = long_trim + trim_inc;
/*scale pct control to degrees deflection*/
/* printf("Long_control: %7.4f, long_trim: %7.4f,DEG_TO_RAD: %7.4f, RAD_TO_DEG: %7.4f\n",Long_control,long_trim,DEG_TO_RAD,RAD_TO_DEG);
*/ /*scale pct control to degrees deflection*/
if ((Long_control+long_trim) <= 0)
elevator=(Long_control+long_trim)*28*DEG_TO_RAD;
else
@ -274,11 +248,8 @@ void aero( SCALAR dt, int Initialize ) {
qScbar=qS*cbar;
qSb=qS*b;
/*transform the aircraft rotation rates*/
ps=-P_body*Cos_alpha + R_body*Sin_alpha;
rs=-P_body*Sin_alpha + R_body*Cos_alpha;
/* printf("Wb: %7.4f, Ub: %7.4f, Alpha: %7.4f, elev: %7.4f, ail: %7.4f, rud: %7.4f\n",W_body,U_body,Alpha*RAD_TO_DEG,elevator*RAD_TO_DEG,aileron*RAD_TO_DEG,rudder*RAD_TO_DEG);
/* printf("Wb: %7.4f, Ub: %7.4f, Alpha: %7.4f, elev: %7.4f, ail: %7.4f, rud: %7.4f, long_trim: %7.4f\n",W_body,U_body,Alpha*RAD_TO_DEG,elevator*RAD_TO_DEG,aileron*RAD_TO_DEG,rudder*RAD_TO_DEG,long_trim*RAD_TO_DEG);
printf("Theta: %7.4f, Gamma: %7.4f, Beta: %7.4f, Phi: %7.4f, Psi: %7.4f\n",Theta*RAD_TO_DEG,Gamma_vert_rad*RAD_TO_DEG,Beta*RAD_TO_DEG,Phi*RAD_TO_DEG,Psi*RAD_TO_DEG);
*/
@ -286,11 +257,11 @@ void aero( SCALAR dt, int Initialize ) {
CLwbh = interp(CLtable,alpha_ind,NCL,Alpha);
CL = CLo + CLwbh + (CLadot*Alpha_dot + CLq*Theta_dot)*cbar_2V + CLde*elevator;
cd = Cdo + rPiARe*CL*CL + Cdde*elevator;
cy = Cybeta*Beta + (Cyp*ps + Cyr*rs)*b_2V + Cyda*aileron + Cydr*rudder;
cy = Cybeta*Beta + (Cyp*P_body + Cyr*R_body)*b_2V + Cyda*aileron + Cydr*rudder;
cm = Cmo + Cma*Alpha + (Cmq*Theta_dot + Cmadot*Alpha_dot)*cbar_2V + Cmde*(elevator+long_trim);
cn = Cnbeta*Beta + (Cnp*ps + Cnr*rs)*b_2V + Cnda*aileron + Cndr*rudder;
croll=Clbeta*Beta + (Clp*ps + Clr*rs)*b_2V + Clda*aileron + Cldr*rudder;
cm = Cmo + Cma*Alpha + (Cmq*Q_body + Cmadot*Alpha_dot)*cbar_2V + Cmde*(elevator+long_trim);
cn = Cnbeta*Beta + (Cnp*P_body + Cnr*R_body)*b_2V + Cnda*aileron + Cndr*rudder;
croll=Clbeta*Beta + (Clp*P_body + Clr*R_body)*b_2V + Clda*aileron + Cldr*rudder;
/* printf("CL: %7.4f, Cd: %7.4f, Cm: %7.4f, Cy: %7.4f, Cn: %7.4f, Cl: %7.4f\n",CL,cd,cm,cy,cn,croll);
*/ /*calculate wind axes forces*/
@ -302,16 +273,12 @@ void aero( SCALAR dt, int Initialize ) {
*/
/*calculate moments and body axis forces */
/*find body-axis components of weight*/
/*with earth axis to body axis transform */
W_X=-1*W*Sin_theta;
W_Y=W*Sin_phi*Cos_theta;
W_Z=W*Cos_phi*Cos_theta;
/* requires ugly wind-axes to body-axes transform */
F_X_aero = W_X + F_X_wind*Cos_alpha*Cos_beta - F_Y_wind*Cos_alpha*Sin_beta - F_Z_wind*Sin_alpha;
F_Y_aero = W_Y + F_X_wind*Sin_beta + F_Y_wind*Cos_beta;
F_Z_aero = W_Z*NZ + F_X_wind*Sin_alpha*Cos_beta - F_Y_wind*Sin_alpha*Sin_beta + F_Z_wind*Cos_alpha;
F_X_aero = F_X_wind*Cos_alpha*Cos_beta - F_Y_wind*Cos_alpha*Sin_beta - F_Z_wind*Sin_alpha;
F_Y_aero = F_X_wind*Sin_beta + F_Y_wind*Cos_beta;
F_Z_aero = F_X_wind*Sin_alpha*Cos_beta - F_Y_wind*Sin_alpha*Sin_beta + F_Z_wind*Cos_alpha;
/*no axes transform here */
M_l_aero = croll*qSb;
@ -319,10 +286,9 @@ void aero( SCALAR dt, int Initialize ) {
M_n_aero = cn*qSb;
/* printf("I_yy: %7.4f, qScbar: %7.4f, qbar: %7.4f, Sw: %7.4f, cbar: %7.4f, 0.5*rho*V^2: %7.4f\n",I_yy,qScbar,Dynamic_pressure,Sw,cbar,0.5*0.0023081*V_rel_wind*V_rel_wind);
printf("Fxbody: %7.4f Fybody: %7.4f Fzbody: %7.4f Weight: %7.4f\n",F_X_wind,F_Y_wind,F_Z_wind,W);
printf("Maero: %7.4f Naero: %7.4f Raero: %7.4f\n",M_m_aero,M_n_aero,M_l_aero);
*/
*/
/* printf("Fxaero: %7.4f Fyaero: %7.4f Fzaero: %7.4f Weight: %7.4f\n",F_X_aero,F_Y_aero,F_Z_aero,W);
*//* printf("Maero: %7.4f Naero: %7.4f Raero: %7.4f\n",M_m_aero,M_n_aero,M_l_aero);
*/
}

55
src/FDM/LaRCsim/c172_aero.h Normal file
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@ -0,0 +1,55 @@
/*c172_aero.h*/
/*global declarations of aero model parameters*/
static SCALAR CLadot;
static SCALAR CLq;
static SCALAR CLde;
static SCALAR CLo;
static SCALAR Cdo;
static SCALAR Cda; /*Not used*/
static SCALAR Cdde;
static SCALAR Cma;
static SCALAR Cmadot;
static SCALAR Cmq;
static SCALAR Cmo;
static SCALAR Cmde;
static SCALAR Clbeta;
static SCALAR Clp;
static SCALAR Clr;
static SCALAR Clda;
static SCALAR Cldr;
static SCALAR Cnbeta;
static SCALAR Cnp;
static SCALAR Cnr;
static SCALAR Cnda;
static SCALAR Cndr;
static SCALAR Cybeta;
static SCALAR Cyp;
static SCALAR Cyr;
static SCALAR Cyda;
static SCALAR Cydr;
/*nondimensionalization quantities*/
/*units here are ft and lbs */
static SCALAR cbar; /*mean aero chord ft*/
static SCALAR b; /*wing span ft */
static SCALAR Sw; /*wing planform surface area ft^2*/
static SCALAR rPiARe; /*reciprocal of Pi*AR*e*/
SCALAR CLwbh,CL,cm,cd,cn,cy,croll,cbar_2V,b_2V,qS,qScbar,qSb,ps,rs;
SCALAR F_X_wind,F_Y_wind,F_Z_wind;
SCALAR long_trim;
SCALAR elevator, aileron, rudder;

2
src/FDM/LaRCsim/c172_engine.c
View file

@ -80,5 +80,3 @@ void engine( SCALAR dt, int init ) {
Throttle_pct = Throttle[3];
}

11
src/FDM/LaRCsim/c172_gear.c
View file

@ -37,8 +37,8 @@
$Header$
$Log$
Revision 1.2 1999/06/21 03:01:47 curt
Updated for both JSBsim and Tony Peden's c172 flight model.
Revision 1.3 1999/07/31 02:57:36 curt
Improvements to Tony's c172 model.
Revision 1.1.1.1 1999/04/05 21:32:45 curt
Start of 0.6.x branch.
@ -93,7 +93,6 @@ Initial Flight Gear revision.
#include "ls_generic.h"
#include "ls_cockpit.h"
void sub3( DATA v1[], DATA v2[], DATA result[] )
{
result[0] = v1[0] - v2[0];
@ -137,6 +136,8 @@ void clear3( DATA v[] )
void gear( SCALAR dt, int Initialize ) {
char rcsid[] = "$Id$";
/*
* Aircraft specific initializations and data goes here
*/
@ -181,7 +182,7 @@ char rcsid[] = "$Id$";
* V V
*/
static DATA sliding_mu = 0.5;
static DATA rolling_mu = 0.01;
static DATA max_brake_mu = 0.6;
@ -208,6 +209,8 @@ char rcsid[] = "$Id$";
int i; /* per wheel loop counter */
Brake_pct=0;
/*
* Execution starts here
*/

11
src/FDM/LaRCsim/c172_init.c
View file

@ -74,3 +74,14 @@ void model_init( void ) {
}
/* a quick navion_init.h */
#ifndef _NAVION_INIT_H
#define _NAVION_INIT_H
void model_init( void );
#endif _NAVION_INIT_H