#include "math/FGMatrix33.h"
#include "input_output/FGXMLElement.h"
#include <vector>
+#include <string>
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
DEFINITIONS
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-#define ID_MASSBALANCE "$Id$"
+#define ID_MASSBALANCE "$Id: FGMassBalance.h,v 1.22 2010/11/18 12:38:06 jberndt Exp $"
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FORWARD DECLARATIONSS
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
+using std::string;
+
namespace JSBSim {
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
/** Models weight, balance and moment of inertia information. Maintains a vector
of point masses. Sums the contribution of all, and provides this to FGPropagate.
- Loads the \<mass_balance> section of the aircraft configuration file.
+ Loads the \<mass_balance> section of the aircraft configuration file. There
+ can be any number of <pointmasses>. Each can also have a shape which - if
+ present - causes an associated moment of inertia to be calculated based on
+ the shape. Note that a cylinder is solid, a tube is hollow, a ball is solid
+ and a sphere is hollow.
<h3>Configuration File Format:</h3>
@code
<ixz unit="{SLUG*FT2 | KG*M2}"> {number} </ixz>
<iyz unit="{SLUG*FT2 | KG*M2}"> {number} </iyz>
<emptywt unit="{LBS | KG"> {number} </emptywt>
- <location name="CG" unit="{IN | M}">
+ <location name="CG" unit="{IN | FT | M}">
<x> {number} </x>
<y> {number} </y>
<z> {number} </z>
</location>
- <pointmass name="{string}">
+ [<pointmass name="{string}">
+ <form shape="{tube | cylinder | sphere | ball}">
+ <radius unit="{IN | FT | M}"> {number} </radius>
+ <length unit="{IN | FT | M}"> {number} </length>
+ </form>
<weight unit="{LBS | KG}"> {number} </weight>
- <location name="POINTMASS" unit="{IN | M}">
+ <location name="{string}" unit="{IN | FT | M}">
<x> {number} </x>
<y> {number} </y>
<z> {number} </z>
</location>
</pointmass>
- ... other point masses ...
+ ... other point masses ...]
</mass_balance>
@endcode
*/
double GetMass(void) const {return Mass;}
double GetWeight(void) const {return Weight;}
- FGColumnVector3& GetXYZcg(void) {return vXYZcg;}
+ double GetEmptyWeight(void) const {return EmptyWeight;}
+ const FGColumnVector3& GetXYZcg(void) const {return vXYZcg;}
double GetXYZcg(int axis) const {return vXYZcg(axis);}
- FGColumnVector3& GetDeltaXYZcg(void) {return vDeltaXYZcg;}
+ const FGColumnVector3& GetDeltaXYZcg(void) const {return vDeltaXYZcg;}
double GetDeltaXYZcg(int axis) const {return vDeltaXYZcg(axis);}
/** Computes the inertia contribution of a pointmass.
*/
FGColumnVector3 StructuralToBody(const FGColumnVector3& r) const;
- inline void SetEmptyWeight(double EW) { EmptyWeight = EW;}
- inline void SetBaseCG(const FGColumnVector3& CG) {vbaseXYZcg = vXYZcg = CG;}
+ void SetEmptyWeight(double EW) { EmptyWeight = EW;}
+ void SetBaseCG(const FGColumnVector3& CG) {vbaseXYZcg = vXYZcg = CG;}
void AddPointMass(Element* el);
double GetTotalPointMassWeight(void);
FGColumnVector3& GetPointMassMoment(void);
- FGMatrix33& GetJ(void) {return mJ;}
- FGMatrix33& GetJinv(void) {return mJinv;}
+ const FGMatrix33& GetJ(void) const {return mJ;}
+ const FGMatrix33& GetJinv(void) const {return mJinv;}
void SetAircraftBaseInertias(FGMatrix33 BaseJ) {baseJ = BaseJ;}
+ void GetMassPropertiesReport(void) const;
private:
double Weight;
FGColumnVector3 PointMassCG;
FGMatrix33& CalculatePMInertias(void);
+
+ /** The PointMass structure encapsulates a point mass object, moments of inertia
+ mass, location, etc. */
struct PointMass {
PointMass(double w, FGColumnVector3& vXYZ) {
Weight = w;
Location = vXYZ;
+ mPMInertia.InitMatrix();
+ Radius = 0.0;
+ Length = 0.0;
}
+
+ void CalculateShapeInertia(void) {
+ switch(eShapeType) {
+ case esTube:
+ mPMInertia(1,1) = (Weight/(slugtolb))*Radius*Radius; // mr^2
+ mPMInertia(2,2) = (Weight/(slugtolb*12))*(6*Radius*Radius + Length*Length);
+ mPMInertia(3,3) = mPMInertia(2,2);
+ break;
+ case esCylinder:
+ mPMInertia(1,1) = (Weight/(slugtolb*2))*Radius*Radius; // 0.5*mr^2
+ mPMInertia(2,2) = (Weight/(slugtolb*12))*(3*Radius*Radius + Length*Length);
+ mPMInertia(3,3) = mPMInertia(2,2);
+ break;
+ case esSphere:
+ mPMInertia(1,1) = (Weight/(slugtolb*3))*Radius*Radius*2; // (2mr^2)/3
+ mPMInertia(2,2) = mPMInertia(1,1);
+ mPMInertia(3,3) = mPMInertia(1,1);
+ case esBall:
+ mPMInertia(1,1) = (Weight/(slugtolb*5))*Radius*Radius*2; // (2mr^2)/5
+ mPMInertia(2,2) = mPMInertia(1,1);
+ mPMInertia(3,3) = mPMInertia(1,1);
+ break;
+ default:
+ break;
+ }
+ }
+
+ enum esShape {esUnspecified, esTube, esCylinder, esSphere, esBall} eShapeType;
FGColumnVector3 Location;
- double Weight;
+ double Weight; /// Weight in pounds.
+ double Radius; /// Radius in feet.
+ double Length; /// Length in feet.
+ string Name;
+ FGMatrix33 mPMInertia;
+
double GetPointMassLocation(int axis) const {return Location(axis);}
+ double GetPointMassWeight(void) const {return Weight;}
+ esShape GetShapeType(void) {return eShapeType;}
+ FGColumnVector3 GetLocation(void) {return Location;}
+ FGMatrix33 GetPointMassInertia(void) {return mPMInertia;}
+ string GetName(void) {return Name;}
+
void SetPointMassLocation(int axis, double value) {Location(axis) = value;}
void SetPointMassWeight(double wt) {Weight = wt;}
- double GetPointMassWeight(void) const {return Weight;}
+ void SetPointMassShapeType(esShape st) {eShapeType = st;}
+ void SetRadius(double r) {Radius = r;}
+ void SetLength(double l) {Length = l;}
+ void SetName(string name) {Name = name;}
+ double GetPointMassMoI(int r, int c) {return mPMInertia(r,c);}
void bind(FGPropertyManager* PropertyManager, int num);
};