Example #1
0
        public StabilityDerivExportOutput CalculateStabilityDerivs(CelestialBody body, double alt, double machNumber, int flapSetting, bool spoilers, double beta, double phi)
        {
            double pressure    = body.GetPressure(alt);
            double temperature = body.GetTemperature(alt);
            double density     = body.GetDensity(pressure, temperature);
            double sspeed      = body.GetSpeedOfSound(pressure, density);
            double u0          = sspeed * machNumber;
            double q           = u0 * u0 * density * 0.5f;

            Vector3d CoM;
            double   mass, area, MAC, b;

            _instantCondition.GetCoMAndSize(out CoM, out mass, out area, out MAC, out b);

            double effectiveG = _instantCondition.CalculateEffectiveGravity(body, alt, u0);
            double neededCl   = effectiveG * mass / (q * area);

            InstantConditionSimVars iterationSimVars =
                new InstantConditionSimVars(_instantCondition, body, alt, machNumber, neededCl, beta, phi, flapSetting, spoilers);
            InstantConditionSimInput           nominalInput;
            InstantConditionSimOutput          nominalOutput;
            InstantConditionSimIterationResult stableCondition =
                iterationSimVars.IterateForAlphaAndPitch(out nominalInput, out nominalOutput);

            InstantConditionSimInput  input = nominalInput.Clone();
            InstantConditionSimOutput pertOutput;

            double[] derivatives = new double[27];

            // update size (in practice MAC and b) to match stableCondition
            _instantCondition.GetCoMAndSize(out CoM, out mass, out area, out MAC, out b);

            double Ix, Iy, Iz;
            double Ixy, Iyz, Ixz;

            _instantCondition.GetInertia(CoM, out Ix, out Iy, out Iz, out Ixy, out Iyz, out Ixz);


            input.alpha = stableCondition.stableAoA + 2;
            iterationSimVars.ResetAndGetClCdCmSteady(input, out pertOutput);

            // Rodhern: A change is made to the Xw formula. Theoretically doing " -= nominalOutput.Cl" is the most 'correct',
            //  it does however in some way mix the Cd value measured at 'stableAoA + 2' with a Cl value measured at 'StableAoA'.
            //  Because Cl and Cd are very AoA-dependent, the asymmetrical measurement (AoA+=[0;2]) is quite affected.
            double pertOutCl = pertOutput.Cl;

            pertOutput.Cl = (pertOutput.Cl - nominalOutput.Cl) / (2 * FARMathUtil.deg2rad);                   //vert vel derivs
            pertOutput.Cd = (pertOutput.Cd - nominalOutput.Cd) / (2 * FARMathUtil.deg2rad);
            pertOutput.Cm = (pertOutput.Cm - nominalOutput.Cm) / (2 * FARMathUtil.deg2rad);

            pertOutput.Cl += nominalOutput.Cd;
            pertOutput.Cd -= pertOutCl; // Rodhern: Convergence is worse, but possibly the numerical value is more useful this way.

            pertOutput.Cl *= -q * area / (mass * u0);
            pertOutput.Cd *= -q * area / (mass * u0);
            pertOutput.Cm *= q * area * MAC / (Iy * u0);

            derivatives[3] = pertOutput.Cl;  //Zw
            derivatives[4] = pertOutput.Cd;  //Xw
            derivatives[5] = pertOutput.Cm;  //Mw


            input.alpha             = stableCondition.stableAoA;
            input.fltenv.MachNumber = machNumber + 0.05;
            iterationSimVars.ResetAndGetClCdCmSteady(input, out pertOutput);

            pertOutput.Cl = (pertOutput.Cl - nominalOutput.Cl) / 0.05 * machNumber;                   //fwd vel derivs
            pertOutput.Cd = (pertOutput.Cd - nominalOutput.Cd) / 0.05 * machNumber;
            pertOutput.Cm = (pertOutput.Cm - nominalOutput.Cm) / 0.05 * machNumber;

            pertOutput.Cl += 2 * nominalOutput.Cl;
            pertOutput.Cd += 2 * nominalOutput.Cd;
            pertOutput.Cm += 2 * nominalOutput.Cm;

            pertOutput.Cl *= -q * area / (mass * u0);
            pertOutput.Cd *= -q * area / (mass * u0);
            pertOutput.Cm *= q * area * MAC / (Iy * u0);

            derivatives[6] = pertOutput.Cl;  //Zu
            derivatives[7] = pertOutput.Cd;  //Xu
            derivatives[8] = pertOutput.Cm;  //Mu


            input.fltenv.MachNumber = machNumber;
            input.alphaDot          = -3;
            iterationSimVars.ResetAndGetClCdCmSteady(input, out pertOutput);

            pertOutput.Cl = (pertOutput.Cl - nominalOutput.Cl) / (3 * FARMathUtil.deg2rad);                   //pitch rate derivs
            pertOutput.Cd = (pertOutput.Cd - nominalOutput.Cd) / (3 * FARMathUtil.deg2rad);
            pertOutput.Cm = (pertOutput.Cm - nominalOutput.Cm) / (3 * FARMathUtil.deg2rad);

            pertOutput.Cl *= -q * area / mass;
            pertOutput.Cd *= -q * area / mass;
            pertOutput.Cm *= q * area * MAC / Iy;

            derivatives[9]  = pertOutput.Cl; //Zq
            derivatives[10] = pertOutput.Cd; //Xq
            derivatives[11] = pertOutput.Cm; //Mq


            input.alphaDot = 0;
            double pitchDelta = (stableCondition.stablePitchValue > 0) ? -0.1 : 0.1;

            input.pitchValue = stableCondition.stablePitchValue + pitchDelta;
            iterationSimVars.ResetAndGetClCdCmSteady(input, out pertOutput);

            pertOutput.Cl = (pertOutput.Cl - nominalOutput.Cl) / pitchDelta;                   //elevator derivs
            pertOutput.Cd = (pertOutput.Cd - nominalOutput.Cd) / pitchDelta;
            pertOutput.Cm = (pertOutput.Cm - nominalOutput.Cm) / pitchDelta;

            pertOutput.Cl *= -q * area / mass; // Rodhern: Replaced 'q' by '-q', so that formulas
            pertOutput.Cd *= -q * area / mass; //  for Ze and Xe match those for Zu and Xu.
            pertOutput.Cm *= q * area * MAC / Iy;

            derivatives[12] = pertOutput.Cl; //Ze
            derivatives[13] = pertOutput.Cd; //Xe
            derivatives[14] = pertOutput.Cm; //Me


            input.pitchValue = stableCondition.stablePitchValue;
            input.beta       = (beta + 2);
            iterationSimVars.ResetAndGetClCdCmSteady(input, out pertOutput);

            pertOutput.Cy     = (pertOutput.Cy - nominalOutput.Cy) / (2 * FARMathUtil.deg2rad);               //sideslip angle derivs
            pertOutput.Cn     = (pertOutput.Cn - nominalOutput.Cn) / (2 * FARMathUtil.deg2rad);
            pertOutput.C_roll = (pertOutput.C_roll - nominalOutput.C_roll) / (2 * FARMathUtil.deg2rad);

            pertOutput.Cy     *= q * area / mass;
            pertOutput.Cn     *= q * area * b / Iz;
            pertOutput.C_roll *= q * area * b / Ix;

            derivatives[15] = pertOutput.Cy;     //Yb
            derivatives[17] = pertOutput.Cn;     //Nb
            derivatives[16] = pertOutput.C_roll; //Lb


            input.beta   = beta;
            input.phiDot = -3;
            iterationSimVars.ResetAndGetClCdCmSteady(input, out pertOutput);

            pertOutput.Cy     = (pertOutput.Cy - nominalOutput.Cy) / (3 * FARMathUtil.deg2rad);               //roll rate derivs
            pertOutput.Cn     = (pertOutput.Cn - nominalOutput.Cn) / (3 * FARMathUtil.deg2rad);
            pertOutput.C_roll = (pertOutput.C_roll - nominalOutput.C_roll) / (3 * FARMathUtil.deg2rad);

            pertOutput.Cy     *= q * area / mass;
            pertOutput.Cn     *= q * area * b / Iz;
            pertOutput.C_roll *= q * area * b / Ix;

            derivatives[18] = pertOutput.Cy;     //Yp
            derivatives[20] = pertOutput.Cn;     //Np
            derivatives[19] = pertOutput.C_roll; //Lp


            input.phiDot  = 0;
            input.betaDot = -3;
            iterationSimVars.ResetAndGetClCdCmSteady(input, out pertOutput);

            pertOutput.Cy     = (pertOutput.Cy - nominalOutput.Cy) / (3 * FARMathUtil.deg2rad);               //yaw rate derivs
            pertOutput.Cn     = (pertOutput.Cn - nominalOutput.Cn) / (3 * FARMathUtil.deg2rad);
            pertOutput.C_roll = (pertOutput.C_roll - nominalOutput.C_roll) / (3 * FARMathUtil.deg2rad);

            pertOutput.Cy     *= q * area / mass;
            pertOutput.Cn     *= q * area * b / Iz;
            pertOutput.C_roll *= q * area * b / Ix;

            derivatives[21] = pertOutput.Cy;     //Yr
            derivatives[23] = pertOutput.Cn;     //Nr
            derivatives[22] = pertOutput.C_roll; //Lr


            input = new InstantConditionSimInput(body); // Reset to (an artificial) default condition
            _instantCondition.ResetClCdCmSteady(CoM, input);

            // Assign values to output variables
            StabilityDerivOutput stabDerivOutput = new StabilityDerivOutput(stableCondition, derivatives);

            stabDerivOutput.nominalVelocity = u0;
            stabDerivOutput.altitude        = alt;
            stabDerivOutput.body            = body;
            stabDerivOutput.b              = b;
            stabDerivOutput.MAC            = MAC;
            stabDerivOutput.area           = area;
            stabDerivOutput.stabDerivs[0]  = Ix;
            stabDerivOutput.stabDerivs[1]  = Iy;
            stabDerivOutput.stabDerivs[2]  = Iz;
            stabDerivOutput.stabDerivs[24] = Ixy;
            stabDerivOutput.stabDerivs[25] = Iyz;
            stabDerivOutput.stabDerivs[26] = Ixz;

            // Assign values to export variables
            StabilityDerivExportVariables stabDerivExport = new StabilityDerivExportVariables();

            stabDerivExport.craftmass      = mass;
            stabDerivExport.envpressure    = pressure;
            stabDerivExport.envtemperature = temperature;
            stabDerivExport.envdensity     = density;
            stabDerivExport.envsoundspeed  = sspeed;
            stabDerivExport.envg           = _instantCondition.CalculateAccelerationDueToGravity(body, alt);
            stabDerivExport.sitmach        = machNumber;
            stabDerivExport.sitdynpres     = q;
            stabDerivExport.siteffg        = _instantCondition.CalculateEffectiveGravity(body, alt, u0);

            return(new StabilityDerivExportOutput(stabDerivOutput, stabDerivExport));
        }
        public StabilityDerivExportOutput CalculateStabilityDerivs(CelestialBody body, double alt, double machNumber, int flapSetting, bool spoilers, double alpha, double beta, double phi)
        {
            double pressure    = body.GetPressure(alt);
            double temperature = body.GetTemperature(alt);
            double density     = body.GetDensity(pressure, temperature);
            double sspeed      = body.GetSpeedOfSound(pressure, density);
            double u0          = sspeed * machNumber;
            double q           = u0 * u0 * density * 0.5f;

            StabilityDerivOutput          stabDerivOutput = new StabilityDerivOutput();
            StabilityDerivExportVariables stabDerivExport = new StabilityDerivExportVariables();

            stabDerivOutput.nominalVelocity = u0;
            stabDerivOutput.altitude        = alt;
            stabDerivOutput.body            = body;

            Vector3d CoM  = Vector3d.zero;
            double   mass = 0;

            double MAC  = 0;
            double b    = 0;
            double area = 0;

            double Ix  = 0;
            double Iy  = 0;
            double Iz  = 0;
            double Ixy = 0;
            double Iyz = 0;
            double Ixz = 0;

            InstantConditionSimInput  input = new InstantConditionSimInput(alpha, beta, phi, 0, 0, 0, machNumber, 0, flapSetting, spoilers);
            InstantConditionSimOutput nominalOutput;
            InstantConditionSimOutput pertOutput = new InstantConditionSimOutput();

            _instantCondition.GetClCdCmSteady(input, out nominalOutput, true);

            List <Part> partsList = EditorLogic.SortedShipList;

            for (int i = 0; i < partsList.Count; i++)
            {
                Part p = partsList[i];

                if (FARAeroUtil.IsNonphysical(p))
                {
                    continue;
                }
                double partMass = p.mass;
                if (p.Resources.Count > 0)
                {
                    partMass += p.GetResourceMass();
                }

                //partMass += p.GetModuleMass(p.mass);
                // If you want to use GetModuleMass, you need to start from p.partInfo.mass, not p.mass
                CoM  += partMass * (Vector3d)p.transform.TransformPoint(p.CoMOffset);
                mass += partMass;
                FARWingAerodynamicModel w = p.GetComponent <FARWingAerodynamicModel>();
                if (w != null)
                {
                    if (w.isShielded)
                    {
                        continue;
                    }

                    area += w.S;
                    MAC  += w.GetMAC() * w.S;
                    b    += w.Getb_2() * w.S;
                    if (w is FARControllableSurface)
                    {
                        (w as FARControllableSurface).SetControlStateEditor(CoM, p.transform.up, 0, 0, 0, input.flaps, input.spoilers);
                    }
                }
            }
            if (area.NearlyEqual(0))
            {
                area = _instantCondition._maxCrossSectionFromBody;
                MAC  = _instantCondition._bodyLength;
                b    = 1;
            }
            MAC  /= area;
            b    /= area;
            CoM  /= mass;
            mass *= 1000;

            stabDerivOutput.b    = b;
            stabDerivOutput.MAC  = MAC;
            stabDerivOutput.area = area;

            for (int i = 0; i < partsList.Count; i++)
            {
                Part p = partsList[i];

                if (p == null || FARAeroUtil.IsNonphysical(p))
                {
                    continue;
                }
                //This section handles the parallel axis theorem
                Vector3 relPos = p.transform.TransformPoint(p.CoMOffset) - CoM;
                double  x2, y2, z2, x, y, z;
                x2 = relPos.z * relPos.z;
                y2 = relPos.x * relPos.x;
                z2 = relPos.y * relPos.y;
                x  = relPos.z;
                y  = relPos.x;
                z  = relPos.y;

                double partMass = p.mass;
                if (p.Resources.Count > 0)
                {
                    partMass += p.GetResourceMass();
                }

                //partMass += p.GetModuleMass(p.mass);
                // If you want to use GetModuleMass, you need to start from p.partInfo.mass, not p.mass

                Ix += (y2 + z2) * partMass;
                Iy += (x2 + z2) * partMass;
                Iz += (x2 + y2) * partMass;

                Ixy += -x * y * partMass;
                Iyz += -z * y * partMass;
                Ixz += -x * z * partMass;

                //And this handles the part's own moment of inertia
                Vector3    principalInertia = p.Rigidbody.inertiaTensor;
                Quaternion prncInertRot     = p.Rigidbody.inertiaTensorRotation;

                //The rows of the direction cosine matrix for a quaternion
                Vector3 Row1 = new Vector3(prncInertRot.x * prncInertRot.x - prncInertRot.y * prncInertRot.y - prncInertRot.z * prncInertRot.z + prncInertRot.w * prncInertRot.w,
                                           2 * (prncInertRot.x * prncInertRot.y + prncInertRot.z * prncInertRot.w),
                                           2 * (prncInertRot.x * prncInertRot.z - prncInertRot.y * prncInertRot.w));

                Vector3 Row2 = new Vector3(2 * (prncInertRot.x * prncInertRot.y - prncInertRot.z * prncInertRot.w),
                                           -prncInertRot.x * prncInertRot.x + prncInertRot.y * prncInertRot.y - prncInertRot.z * prncInertRot.z + prncInertRot.w * prncInertRot.w,
                                           2 * (prncInertRot.y * prncInertRot.z + prncInertRot.x * prncInertRot.w));

                Vector3 Row3 = new Vector3(2 * (prncInertRot.x * prncInertRot.z + prncInertRot.y * prncInertRot.w),
                                           2 * (prncInertRot.y * prncInertRot.z - prncInertRot.x * prncInertRot.w),
                                           -prncInertRot.x * prncInertRot.x - prncInertRot.y * prncInertRot.y + prncInertRot.z * prncInertRot.z + prncInertRot.w * prncInertRot.w);


                //And converting the principal moments of inertia into the coordinate system used by the system
                Ix += principalInertia.x * Row1.x * Row1.x + principalInertia.y * Row1.y * Row1.y + principalInertia.z * Row1.z * Row1.z;
                Iy += principalInertia.x * Row2.x * Row2.x + principalInertia.y * Row2.y * Row2.y + principalInertia.z * Row2.z * Row2.z;
                Iz += principalInertia.x * Row3.x * Row3.x + principalInertia.y * Row3.y * Row3.y + principalInertia.z * Row3.z * Row3.z;

                Ixy += principalInertia.x * Row1.x * Row2.x + principalInertia.y * Row1.y * Row2.y + principalInertia.z * Row1.z * Row2.z;
                Ixz += principalInertia.x * Row1.x * Row3.x + principalInertia.y * Row1.y * Row3.y + principalInertia.z * Row1.z * Row3.z;
                Iyz += principalInertia.x * Row2.x * Row3.x + principalInertia.y * Row2.y * Row3.y + principalInertia.z * Row2.z * Row3.z;
            }
            Ix *= 1000;
            Iy *= 1000;
            Iz *= 1000;

            stabDerivOutput.stabDerivs[0] = Ix;
            stabDerivOutput.stabDerivs[1] = Iy;
            stabDerivOutput.stabDerivs[2] = Iz;

            stabDerivOutput.stabDerivs[24] = Ixy;
            stabDerivOutput.stabDerivs[25] = Iyz;
            stabDerivOutput.stabDerivs[26] = Ixz;


            double effectiveG = _instantCondition.CalculateAccelerationDueToGravity(body, alt); //This is the effect of gravity

            effectiveG -= u0 * u0 / (alt + body.Radius);                                        //This is the effective reduction of gravity due to high velocity
            double neededCl = mass * effectiveG / (q * area);


            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, true);
            //Longitudinal Mess
            _instantCondition.SetState(machNumber, neededCl, CoM, 0, input.flaps, input.spoilers);

            alpha         = FARMathUtil.SelectedSearchMethod(machNumber, _instantCondition.FunctionIterateForAlpha);
            input.alpha   = alpha;
            nominalOutput = _instantCondition.iterationOutput;
            //alpha_str = (alpha * Mathf.PI / 180).ToString();

            input.alpha = (alpha + 2);

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, true);

            stabDerivOutput.stableCl       = neededCl;
            stabDerivOutput.stableCd       = nominalOutput.Cd;
            stabDerivOutput.stableAoA      = alpha;
            stabDerivOutput.stableAoAState = "";
            if (Math.Abs((nominalOutput.Cl - neededCl) / neededCl) > 0.1)
            {
                stabDerivOutput.stableAoAState = ((nominalOutput.Cl > neededCl) ? "<" : ">");
            }

            FARLogger.Info("Cl needed: " + neededCl + ", AoA: " + alpha + ", Cl: " + nominalOutput.Cl + ", Cd: " + nominalOutput.Cd);

            pertOutput.Cl = (pertOutput.Cl - nominalOutput.Cl) / (2 * FARMathUtil.deg2rad);                   //vert vel derivs
            pertOutput.Cd = (pertOutput.Cd - nominalOutput.Cd) / (2 * FARMathUtil.deg2rad);
            pertOutput.Cm = (pertOutput.Cm - nominalOutput.Cm) / (2 * FARMathUtil.deg2rad);

            pertOutput.Cl += nominalOutput.Cd;
            pertOutput.Cd -= nominalOutput.Cl;

            pertOutput.Cl *= -q * area / (mass * u0);
            pertOutput.Cd *= -q * area / (mass * u0);
            pertOutput.Cm *= q * area * MAC / (Iy * u0);

            stabDerivOutput.stabDerivs[3] = pertOutput.Cl;  //Zw
            stabDerivOutput.stabDerivs[4] = pertOutput.Cd;  //Xw
            stabDerivOutput.stabDerivs[5] = pertOutput.Cm;  //Mw

            // Rodhern: The motivation for the revised stability derivatives sign interpretations of Zq, Xq, Ze and Xe
            //  is to align the sign conventions used for Zu, Zq, Ze, Xu, Xq and Xe. Further explanation can be found
            //  here: https://forum.kerbalspaceprogram.com/index.php?/topic/109098-official-far-craft-repository/&do=findComment&comment=2425057

            input.alpha      = alpha;
            input.machNumber = machNumber + 0.05;

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, false);

            pertOutput.Cl = (pertOutput.Cl - nominalOutput.Cl) / 0.05 * machNumber;                   //fwd vel derivs
            pertOutput.Cd = (pertOutput.Cd - nominalOutput.Cd) / 0.05 * machNumber;
            pertOutput.Cm = (pertOutput.Cm - nominalOutput.Cm) / 0.05 * machNumber;

            pertOutput.Cl += 2 * nominalOutput.Cl;
            pertOutput.Cd += 2 * nominalOutput.Cd;

            pertOutput.Cl *= -q * area / (mass * u0);
            pertOutput.Cd *= -q * area / (mass * u0);
            pertOutput.Cm *= q * area * MAC / (u0 * Iy);

            stabDerivOutput.stabDerivs[6] = pertOutput.Cl;  //Zu
            stabDerivOutput.stabDerivs[7] = pertOutput.Cd;  //Xu
            stabDerivOutput.stabDerivs[8] = pertOutput.Cm;  //Mu

            input.machNumber = machNumber;

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, true);

            input.alphaDot = -0.05;

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, false);

            pertOutput.Cl = (pertOutput.Cl - nominalOutput.Cl) / 0.05;                   //pitch rate derivs
            pertOutput.Cd = (pertOutput.Cd - nominalOutput.Cd) / 0.05;
            pertOutput.Cm = (pertOutput.Cm - nominalOutput.Cm) / 0.05;

            pertOutput.Cl *= -q * area * MAC / (2 * u0 * mass); // Rodhern: Replaced 'q' by '-q', so that formulas
            pertOutput.Cd *= -q * area * MAC / (2 * u0 * mass); //  for Zq and Xq match those for Zu and Xu.
            pertOutput.Cm *= q * area * MAC * MAC / (2 * u0 * Iy);

            stabDerivOutput.stabDerivs[9]  = pertOutput.Cl; //Zq
            stabDerivOutput.stabDerivs[10] = pertOutput.Cd; //Xq
            stabDerivOutput.stabDerivs[11] = pertOutput.Cm; //Mq

            input.alphaDot   = 0;
            input.pitchValue = 0.1;

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, false);

            pertOutput.Cl = (pertOutput.Cl - nominalOutput.Cl) / 0.1;                   //elevator derivs
            pertOutput.Cd = (pertOutput.Cd - nominalOutput.Cd) / 0.1;
            pertOutput.Cm = (pertOutput.Cm - nominalOutput.Cm) / 0.1;

            pertOutput.Cl *= -q * area / mass; // Rodhern: Replaced 'q' by '-q', so that formulas
            pertOutput.Cd *= -q * area / mass; //  for Ze and Xe match those for Zu and Xu.
            pertOutput.Cm *= q * area * MAC / Iy;

            stabDerivOutput.stabDerivs[12] = pertOutput.Cl; //Ze
            stabDerivOutput.stabDerivs[13] = pertOutput.Cd; //Xe
            stabDerivOutput.stabDerivs[14] = pertOutput.Cm; //Me

            //Lateral Mess

            input.pitchValue = 0;
            input.beta       = (beta + 2);

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, false);
            pertOutput.Cy     = (pertOutput.Cy - nominalOutput.Cy) / (2 * FARMathUtil.deg2rad);               //sideslip angle derivs
            pertOutput.Cn     = (pertOutput.Cn - nominalOutput.Cn) / (2 * FARMathUtil.deg2rad);
            pertOutput.C_roll = (pertOutput.C_roll - nominalOutput.C_roll) / (2 * FARMathUtil.deg2rad);

            pertOutput.Cy     *= q * area / mass;
            pertOutput.Cn     *= q * area * b / Iz;
            pertOutput.C_roll *= q * area * b / Ix;

            stabDerivOutput.stabDerivs[15] = pertOutput.Cy;     //Yb
            stabDerivOutput.stabDerivs[17] = pertOutput.Cn;     //Nb
            stabDerivOutput.stabDerivs[16] = pertOutput.C_roll; //Lb

            input.beta = beta;

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, true);

            input.phiDot = -0.05;

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, false);

            pertOutput.Cy     = (pertOutput.Cy - nominalOutput.Cy) / 0.05;               //roll rate derivs
            pertOutput.Cn     = (pertOutput.Cn - nominalOutput.Cn) / 0.05;
            pertOutput.C_roll = (pertOutput.C_roll - nominalOutput.C_roll) / 0.05;

            pertOutput.Cy     *= q * area * b / (2 * mass * u0);
            pertOutput.Cn     *= q * area * b * b / (2 * Iz * u0);
            pertOutput.C_roll *= q * area * b * b / (2 * Ix * u0);

            stabDerivOutput.stabDerivs[18] = pertOutput.Cy;     //Yp
            stabDerivOutput.stabDerivs[20] = pertOutput.Cn;     //Np
            stabDerivOutput.stabDerivs[19] = pertOutput.C_roll; //Lp


            input.phiDot = 0;

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, true);

            input.betaDot = -0.05;

            _instantCondition.GetClCdCmSteady(input, out pertOutput, true, false); pertOutput.Cy = (pertOutput.Cy - nominalOutput.Cy) / 0.05f;                   //yaw rate derivs
            pertOutput.Cn     = (pertOutput.Cn - nominalOutput.Cn) / 0.05f;
            pertOutput.C_roll = (pertOutput.C_roll - nominalOutput.C_roll) / 0.05f;

            pertOutput.Cy     *= q * area * b / (2 * mass * u0);
            pertOutput.Cn     *= q * area * b * b / (2 * Iz * u0);
            pertOutput.C_roll *= q * area * b * b / (2 * Ix * u0);

            stabDerivOutput.stabDerivs[21] = pertOutput.Cy;     //Yr
            stabDerivOutput.stabDerivs[23] = pertOutput.Cn;     //Nr
            stabDerivOutput.stabDerivs[22] = pertOutput.C_roll; //Lr

            // Assign values to export variables
            stabDerivExport.craftmass      = mass;
            stabDerivExport.envpressure    = pressure;
            stabDerivExport.envtemperature = temperature;
            stabDerivExport.envdensity     = density;
            stabDerivExport.envsoundspeed  = sspeed;
            stabDerivExport.envg           = _instantCondition.CalculateAccelerationDueToGravity(body, alt);
            stabDerivExport.sitmach        = machNumber;
            stabDerivExport.sitdynpres     = q;
            stabDerivExport.siteffg        = effectiveG;

            return(new StabilityDerivExportOutput(stabDerivOutput, stabDerivExport));
        }
 public StabilityDerivExportOutput(StabilityDerivOutput outputvalues, StabilityDerivExportVariables exportvalues)
 {
     this.outputvals = outputvalues;
     this.exportvals = exportvalues;
 }