gtoc5_launch.cpp

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 *   Copyright (C) 2004-2015 The PaGMO development team,                     *
 *   Advanced Concepts Team (ACT), European Space Agency (ESA)               *
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 *   act@esa.int                                                             *
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#include <string>

#include <boost/integer_traits.hpp>
#include <boost/math/constants/constants.hpp>
#include <boost/numeric/conversion/bounds.hpp>
#include <boost/numeric/conversion/cast.hpp>
#include <cmath>
#include <sstream>
#include <stdexcept>
#include <vector>

#include "../exceptions.h"
#include "../types.h"
#include "base.h"
#include "gtoc5_launch.h"
#include <keplerian_toolbox/sims_flanagan/codings.h>
#include <keplerian_toolbox/astro_constants.h>
#include <keplerian_toolbox/planet/gtoc5.h>

using namespace kep_toolbox;
using namespace kep_toolbox::sims_flanagan;

namespace pagmo { namespace problem {

gtoc5_launch::gtoc5_launch(int segments, int target, objective obj, const double &ctol) :
        base(segments * 3 + 6, 0, 1, 7 + segments + 1, segments + 1,ctol),
        m_n_segments(segments),m_earth(),m_target(target),m_obj(obj)
{
        std::vector<double> lb_v(get_dimension());
        std::vector<double> ub_v(get_dimension());

        // Start (MJD).
        lb_v[0] = 57023;
        ub_v[0] = 61041;

        // Leg duration in days
        lb_v[1] = 30;
        ub_v[1] = 365.25 * 3;

        // Final mass.
        lb_v[2] = 500;
        ub_v[2] = 4000;

        // Start Velocity
        lb_v[3] = -5000;
        lb_v[4] = -5000;
        lb_v[5] = -5000;
        ub_v[3] = 5000;
        ub_v[4] = 5000;
        ub_v[5] = 5000;

        // I Throttles
        for (int i = 6; i < segments * 3 + 6; ++i)
        {
                lb_v[i] = -1;
                ub_v[i] = 1;
        }

        //Copying the lb,ub vector into the problems bounds
        set_bounds(lb_v,ub_v);
        
        // Set GTOC5 spacecraft.
        m_leg.set_spacecraft(kep_toolbox::sims_flanagan::spacecraft(4000,0.3,3000));
}

base_ptr gtoc5_launch::clone() const
{
        return base_ptr(new gtoc5_launch(*this));
}

void gtoc5_launch::objfun_impl(fitness_vector &f, const decision_vector &x) const
{
        if (m_obj == MASS) {
                f[0] = -x[2] / m_leg.get_spacecraft().get_mass();
        } else {
                f[0] = x[1] / 365.25;
        }
}

void gtoc5_launch::compute_constraints_impl(constraint_vector &c, const decision_vector &x) const
{
        using namespace kep_toolbox;
        // 1 - We set the leg.
        const epoch epoch_i(x[0],epoch::MJD), epoch_f(x[1] + x[0],epoch::MJD);
        array3D v0, r0, vf, rf;
        m_earth.eph(epoch_i,r0,v0);
        m_target.eph(epoch_f,rf,vf);

        v0[0] += x[3];
        v0[1] += x[4];
        v0[2] += x[5];
        m_leg.set_leg(epoch_i,sc_state(r0,v0,m_leg.get_spacecraft().get_mass()),x.begin() + 6, x.end(),epoch_f,sc_state(rf,vf,x[2]),ASTRO_MU_SUN);

        // We evaluate the state mismatch at the mid-point. And we use astronomical units to scale them
        m_leg.get_mismatch_con(c.begin(), c.begin() + 7);
        for (int i=0; i<3; ++i) c[i]/=ASTRO_AU;
        for (int i=3; i<6; ++i) c[i]/=ASTRO_EARTH_VELOCITY;
        c[6] /= m_leg.get_spacecraft().get_mass();
        // We evaluate the constraints on the throttles writing on the 7th mismatch constrant (mass is off)
        m_leg.get_throttles_con(c.begin() + 7, c.begin() + 7 + m_n_segments);
        c[7 + m_n_segments] = (x[3]*x[3] + x[4]*x[4] + x[5]*x[5] - 25000000) / ASTRO_EARTH_VELOCITY / ASTRO_EARTH_VELOCITY;
}

void gtoc5_launch::set_sparsity(int &lenG, std::vector<int> &iGfun, std::vector<int> &jGvar) const
{
        //Initial point
        decision_vector x0(get_dimension());
        for (pagmo::decision_vector::size_type i = 0; i<x0.size(); ++i)
        {
                x0[i] = get_lb()[i] + (get_ub()[i] - get_lb()[i]) / 3.12345;
        }
        //Numerical procedure
        estimate_sparsity(x0, lenG, iGfun, jGvar);
}

std::string gtoc5_launch::get_name() const
{
        return "GTOC5 Launch phase";
}

std::string gtoc5_launch::pretty(const decision_vector &x) const
{
        using namespace kep_toolbox;
        // 1 - We set the leg.
        const epoch epoch_i(x[0],epoch::MJD), epoch_f(x[1] + x[0],epoch::MJD);
        array3D v0, r0, vf, rf;
        m_earth.eph(epoch_i,r0,v0);
        m_target.eph(epoch_f,rf,vf);

        v0[0] += x[2];
        v0[1] += x[3];
        v0[2] += x[4];
        m_leg.set_leg(epoch_i,sc_state(r0,v0,m_leg.get_spacecraft().get_mass()),x.begin() + 6, x.end(),epoch_f,sc_state(rf,vf,x[5]),ASTRO_MU_SUN);

        std::ostringstream oss;
        oss << m_leg << '\n' << m_earth << '\n' << m_target << '\n';
        return oss.str();
}

}}

BOOST_CLASS_EXPORT_IMPLEMENT(pagmo::problem::gtoc5_launch);