289 lines
9.8 KiB
C++
289 lines
9.8 KiB
C++
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
Header: FGTrim.h
|
|
Author: Tony Peden
|
|
Date started: 7/1/99
|
|
|
|
------------- Copyright (C) 1999 Anthony K. Peden (apeden@earthlink.net) -------------
|
|
|
|
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., 59 Temple
|
|
Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
|
|
Further information about the GNU General Public License can also be found on
|
|
the world wide web at http://www.gnu.org.
|
|
|
|
|
|
HISTORY
|
|
--------------------------------------------------------------------------------
|
|
9/8/99 TP Created
|
|
|
|
|
|
FUNCTIONAL DESCRIPTION
|
|
--------------------------------------------------------------------------------
|
|
|
|
This class takes the given set of IC's and finds the angle of attack, elevator,
|
|
and throttle setting required to fly steady level. This is currently for in-air
|
|
conditions only. It is implemented using an iterative, one-axis-at-a-time
|
|
scheme.
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
SENTRY
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
|
|
|
|
#ifndef FGTRIM_H
|
|
#define FGTRIM_H
|
|
|
|
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
INCLUDES
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
|
|
|
|
#include "FGFDMExec.h"
|
|
#include "FGRotation.h"
|
|
#include "FGAtmosphere.h"
|
|
#include "FGState.h"
|
|
#include "FGFCS.h"
|
|
#include "FGAircraft.h"
|
|
#include "FGTranslation.h"
|
|
#include "FGPosition.h"
|
|
#include "FGAuxiliary.h"
|
|
#include "FGOutput.h"
|
|
#include "FGTrim.h"
|
|
#include "FGTrimAxis.h"
|
|
|
|
#include <vector>
|
|
|
|
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
DEFINITIONS
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
|
|
|
|
#define ID_TRIM "$Id$"
|
|
|
|
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
FORWARD DECLARATIONS
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
|
|
|
|
typedef enum { tLongitudinal, tFull, tGround, tCustom, tNone } TrimMode;
|
|
|
|
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
COMMENTS, REFERENCES, and NOTES [use "class documentation" below for API docs]
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
|
|
|
|
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
CLASS DOCUMENTATION
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
|
|
|
|
/** FGTrim -- the trimming routine for JSBSim.
|
|
FGTrim finds the aircraft attitude and control settings needed to maintain
|
|
the steady state described by the FGInitialCondition object . It does this
|
|
iteratively by assigning a control to each state and adjusting that control
|
|
until the state is within a specified tolerance of zero. States include the
|
|
recti-linear accelerations udot, vdot, and wdot, the angular accelerations
|
|
qdot, pdot, and rdot, and the difference between heading and ground track.
|
|
Controls include the usual flight deck controls available to the pilot plus
|
|
angle of attack (alpha), sideslip angle(beta), flight path angle (gamma),
|
|
pitch attitude(theta), roll attitude(phi), and altitude above ground. The
|
|
last three are used for on-ground trimming. The state-control pairs used in
|
|
a given trim are completely user configurable and several pre-defined modes
|
|
are provided as well. They are:
|
|
<ul>
|
|
<li> tLongitudinal: Trim wdot with alpha, udot with thrust, qdot with elevator</li>
|
|
<li> tFull: tLongitudinal + vdot with phi, pdot with aileron, rdot with rudder
|
|
and heading minus ground track (hmgt) with beta</li>
|
|
<li> tGround: wdot with altitude, qdot with theta, and pdot with phi</li>
|
|
The remaining modes include <b>tCustom</b>, which is completely user defined and
|
|
<b>tNone</b>.
|
|
</ul>
|
|
Currently, this class cannot trim a non-1g condition and is limited to
|
|
trimming for constant true airspeed in climbs and descents.
|
|
|
|
Note that trims can (and do) fail for reasons that are completely outside
|
|
the control of the trimming routine itself. The most common problem is the
|
|
initial conditions: is the model capable of steady state flight
|
|
at those conditions? Check the speed, altitude, configuration (flaps,
|
|
gear, etc.), weight, cg, and anything else that may be relevant.
|
|
|
|
Example usage:
|
|
FGFDMExec* FDMExec = new FGFDMExec();
|
|
.
|
|
.
|
|
.
|
|
FGInitialCondition* fgic = new FGInitialCondition(FDMExec);
|
|
FGTrim *fgt(FDMExec,fgic,tFull);
|
|
fgic->SetVcaibratedKtsIC(100);
|
|
fgic->SetAltitudeFtIC(1000);
|
|
fgic->SetClimbRate(500);
|
|
if( !fgt->DoTrim() ) {
|
|
cout << "Trim Failed" << endl;
|
|
}
|
|
fgt->ReportState();
|
|
@author Tony Peden
|
|
@version $Id$
|
|
*/
|
|
|
|
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
CLASS DECLARATION
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
|
|
|
|
class FGTrim {
|
|
private:
|
|
|
|
vector<FGTrimAxis*> TrimAxes;
|
|
int current_axis;
|
|
int N, Nsub;
|
|
TrimMode mode;
|
|
int Debug;
|
|
float Tolerance, A_Tolerance;
|
|
float wdot,udot,qdot;
|
|
float dth;
|
|
float *sub_iterations;
|
|
float *successful;
|
|
bool *solution;
|
|
int max_sub_iterations;
|
|
int max_iterations;
|
|
int total_its;
|
|
bool trimudot;
|
|
bool gamma_fallback;
|
|
bool trim_failed;
|
|
int axis_count;
|
|
int solutionDomain;
|
|
float xlo,xhi,alo,ahi;
|
|
|
|
FGFDMExec* fdmex;
|
|
FGInitialCondition* fgic;
|
|
|
|
bool solve(void);
|
|
|
|
/** @return false if there is no change in the current axis accel
|
|
between accel(control_min) and accel(control_max). If there is a
|
|
change, sets solutionDomain to:
|
|
0 for no sign change,
|
|
-1 if sign change between accel(control_min) and accel(0)
|
|
1 if sign between accel(0) and accel(control_max)
|
|
*/
|
|
bool findInterval(void);
|
|
|
|
bool checkLimits(void);
|
|
|
|
public:
|
|
/** Initializes the trimming class
|
|
@param FDMExec pointer to a JSBSim executive object.
|
|
@param FGIC pointer to a FGInitialCondition object
|
|
@param TrimMode the set of axes to trim. Can be:
|
|
tLongitudinal, tFull, tGround, tCustom, or tNone
|
|
*/
|
|
FGTrim(FGFDMExec *FDMExec, FGInitialCondition *FGIC, TrimMode tt);
|
|
|
|
~FGTrim(void);
|
|
|
|
/** Execute the trim
|
|
*/
|
|
bool DoTrim(void);
|
|
|
|
/** Print the results of the trim. For each axis trimmed, this
|
|
includes the final state value, control value, and tolerance
|
|
used.
|
|
@return true if trim succeeds
|
|
*/
|
|
void Report(void);
|
|
|
|
/** Prints a summary of simulator state (speed, altitude,
|
|
configuration, etc.)
|
|
*/
|
|
void ReportState(void);
|
|
|
|
/** Iteration statistics
|
|
*/
|
|
void TrimStats();
|
|
|
|
/** Clear all state-control pairs from the current configuration.
|
|
The trimming routine must have at least one state-control pair
|
|
configured to be useful
|
|
*/
|
|
void ClearStates(void);
|
|
|
|
/** Add a state-control pair to the current configuration. See the enums
|
|
State and Control in FGTrimAxis.h for the available options.
|
|
Will fail if the given state is already configured.
|
|
@param state the accel or other condition to zero
|
|
@param control the control used to zero the state
|
|
@return true if add is successful
|
|
*/
|
|
bool AddState( State state, Control control );
|
|
|
|
/** Remove a specific state-control pair from the current configuration
|
|
@param state the state to remove
|
|
@return true if removal is successful
|
|
*/
|
|
bool RemoveState( State state );
|
|
|
|
/** Change the control used to zero a state previously configured
|
|
@param state the accel or other condition to zero
|
|
@param control the control used to zero the state
|
|
*/
|
|
bool EditState( State state, Control new_control );
|
|
|
|
/** automatically switch to trimming longitudinal acceleration with
|
|
flight path angle (gamma) once it becomes apparent that there
|
|
is not enough/too much thrust.
|
|
@param gamma_fallback true to enable fallback
|
|
*/
|
|
inline void SetGammaFallback(bool bb) { gamma_fallback=true; }
|
|
|
|
/** query the fallback state
|
|
@return true if fallback is enabled.
|
|
*/
|
|
inline bool GetGammaFallback(void) { return gamma_fallback; }
|
|
|
|
/** Set the iteration limit. DoTrim() will return false if limit
|
|
iterations are reached before trim is achieved. The default
|
|
is 60. This does not ordinarily need to be changed.
|
|
@param ii integer iteration limit
|
|
*/
|
|
inline void SetMaxCycles(int ii) { max_iterations = ii; }
|
|
|
|
/** Set the per-axis iteration limit. Attempt to zero each state
|
|
by iterating limit times before moving on to the next. The
|
|
default limit is 100 and also does not ordinarily need to
|
|
be changed.
|
|
@param ii integer iteration limit
|
|
*/
|
|
inline void SetMaxCyclesPerAxis(int ii) { max_sub_iterations = ii; }
|
|
|
|
/** Set the tolerance for declaring a state trimmed. Angular accels are
|
|
held to a tolerance of 1/10th of the given. The default is
|
|
0.001 for the recti-linear accelerations and 0.0001 for the angular.
|
|
*/
|
|
inline void SetTolerance(float tt) {
|
|
Tolerance = tt;
|
|
A_Tolerance = tt / 10;
|
|
}
|
|
|
|
//Debug level 1 shows results of each top-level iteration
|
|
//Debug level 2 shows level 1 & results of each per-axis iteration
|
|
inline void SetDebug(int level) { Debug = level; }
|
|
inline void ClearDebug(void) { Debug = 0; }
|
|
|
|
};
|
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|