-/*******************************************************************************
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Header: FGTrim.h
Author: Tony Peden
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.
+This class takes the given set of IC's and finds the aircraft state required to
+maintain a specified flight condition. This flight condition can be
+steady-level with non-zero sideslip, a steady turn, a pull-up or pushover.
+On-ground conditions can be trimmed as well, but this is currently limited to
+adjusting altitude and pitch angle 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 "FGJSBBase.h"
#include "FGTrimAxis.h"
-#include <vector.h>
+#include <vector>
-#define ID_TRIM "$Header"
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+DEFINITIONS
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-/*******************************************************************************
-CLASS DECLARATION
-*******************************************************************************/
+#define ID_TRIM "$Id$"
+
+#if defined(_WIN32) && !defined(__CYGWIN__)
+ #define snprintf _snprintf
+#endif
+
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+FORWARD DECLARATIONS
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
+
+namespace JSBSim {
-typedef enum { tLongitudinal, tFull, tGround } TrimMode;
+typedef enum { tLongitudinal, tFull, tGround, tPullup,
+ tCustom, tNone, tTurn
+ } TrimMode;
-class FGTrim {
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+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:
+ - tLongitudinal: Trim wdot with alpha, udot with thrust, qdot with elevator
+ - tFull: tLongitudinal + vdot with phi, pdot with aileron, rdot with rudder
+ and heading minus ground track (hmgt) with beta
+ - tPullup: tLongitudinal but adjust alpha to achieve load factor input
+ with SetTargetNlf()
+ - tGround: wdot with altitude, qdot with theta, and pdot with phi
+
+ The remaining modes include <b>tCustom</b>, which is completely user defined and
+ <b>tNone</b>.
+
+ 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:<pre>
+ 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(); </pre>
+ @author Tony Peden
+ @version "$Id$"
+*/
+
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+CLASS DECLARATION
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
+
+class FGTrim : public FGJSBBase
+{
private:
vector<FGTrimAxis*> TrimAxes;
- int current_axis;
+ unsigned int current_axis;
int N, Nsub;
- int NumAxes;
TrimMode mode;
- int Debug;
- float Tolerance, A_Tolerance;
- float wdot,udot,qdot;
- float dth;
- float *sub_iterations;
- float *successful;
+ int DebugLevel, Debug;
+ double Tolerance, A_Tolerance;
+ double wdot,udot,qdot;
+ double dth;
+ double *sub_iterations;
+ double *successful;
bool *solution;
int max_sub_iterations;
int max_iterations;
bool trimudot;
bool gamma_fallback;
bool trim_failed;
- int axis_count;
+ unsigned int axis_count;
int solutionDomain;
- float xlo,xhi,alo,ahi;
-
+ double xlo,xhi,alo,ahi;
+ double targetNlf;
+ int debug_axis;
+
+ double psidot,thetadot;
FGFDMExec* fdmex;
FGInitialCondition* fgic;
-
- // returns 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 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);
+
+ void setupPullup(void);
+ void setupTurn(void);
+
+ void updateRates(void);
+
+ void setDebug(void);
public:
- FGTrim(FGFDMExec *FDMExec, FGInitialCondition *FGIC, TrimMode tt);
+ /** Initializes the trimming class
+ @param FDMExec pointer to a JSBSim executive object.
+ @param tm trim mode
+ */
+ FGTrim(FGFDMExec *FDMExec, TrimMode tm=tGround );
+
~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);
- void ReportState(void);
+
+ /** Iteration statistics
+ */
void TrimStats();
+
+ /** Clear all state-control pairs and set a predefined trim mode
+ @param tm the set of axes to trim. Can be:
+ tLongitudinal, tFull, tGround, tCustom, or tNone
+ */
+ void SetMode(TrimMode tm);
+
+ /** 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);
- inline void SetUdotTrim(bool bb) { trimudot=bb; }
- inline bool GetUdotTrim(void) { return trimudot; }
+ /** 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 new_control the control used to zero the state
+ */
+ bool EditState( State state, Control new_control );
- inline void SetGammaFallback(bool bb) { gamma_fallback=true; }
+ /** automatically switch to trimming longitudinal acceleration with
+ flight path angle (gamma) once it becomes apparent that there
+ is not enough/too much thrust.
+ @param bb true to enable fallback
+ */
+ inline void SetGammaFallback(bool bb) { gamma_fallback=bb; }
+
+ /** 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; }
- inline void SetTolerance(float tt) {
+
+ /** 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(double 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; }
+
+ /**
+ 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) { DebugLevel = level; }
+ inline void ClearDebug(void) { DebugLevel = 0; }
+
+ /**
+ Output debug data for one of the axes
+ The State enum is defined in FGTrimAxis.h
+ */
+ inline void DebugState(State state) { debug_axis=state; }
+
+ inline void SetTargetNlf(float nlf) { targetNlf=nlf; }
+ inline double GetTargetNlf(void) { return targetNlf; }
};
-
+}
#endif
-
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projects / flightgear.git / blobdiff