CR3BPDynamicsModel.h

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/*
Circular restricted three body dynamics header file
 
Author: Alex Reynolds
*/
 
#ifndef MODELS_ACTUATORS_CR3BP_DYNAMICS_MODEL_H
#define MODELS_ACTUATORS_CR3BP_DYNAMICS_MODEL_H
 
#include "core/macros.h"
#include "simulation/Model.h"
#include "cr3bputils/CR3BPDynamics.hpp"
 
namespace modelspace {
 
    /**
     * @brief   Circular Restricted Three Body Problem Dynamics Model
     * 
     * This model calculates the expected acceleration experienced by a 
     * body acting under three-body dynamics using the circular restricted
     * three body assumptions. 
     * 
     * Note the synodic frame definition is consistent with the definitions
     * in this same directory, which is as follows:
     * - Frame centered at the system barycenter
     * - Frame +x directed from the major body to the minor body
     * - Frame +z aligned to the minor body's angular momentum vector
     * - Frame +y completes the RH frame along the definition of minor planet travel
     * 
     * Key assumptions:
     * - The model outputs acceleration, not force, and so to apply it to a
     *   ModelSpace frame requires conversion or a body with unit mass
    */
    class CR3BPDynamicsModel : public modelspace::Model {
    public:
        // Model params
        //         NAME                     TYPE                    DEFAULT VALUE
        START_PARAMS
            /** The non-dimensional ratio of the mass of the primary body to the mass
             *  of the secondary body in the three body system. */
            SIGNAL(mu_star,                 double,                 0.0)
        END_PARAMS
 
        // Model inputs
        //         NAME                     TYPE                    DEFAULT VALUE
        START_INPUTS
            /** The position of the spacecraft in the rotating three body "synodic" frame */
            SIGNAL(pos_synodic,             CartesianVector3D,      CartesianVector3D({0.0, 0.0, 0.0}))
            /** The velocity of the spacecraft in the rotating three body "synodic" frame */
            SIGNAL(vel_synodic,             CartesianVector3D,      CartesianVector3D({0.0, 0.0, 0.0}))
        END_INPUTS
 
        // Model outputs
        //         NAME                     TYPE                    DEFAULT VALUE
        START_OUTPUTS
            /** The acceleration of the spacecraft in the rotating three body "synodic" frame */
            SIGNAL(accel_synodic,           CartesianVector3D,      CartesianVector3D({0.0, 0.0, 0.0}))
        END_OUTPUTS
 
        // Model-specific implementations of startup and derivative
        CR3BPDynamicsModel() : modelspace::Model() { }
        CR3BPDynamicsModel(modelspace::Model &pnt, int schedule_slot=0, const std::string &m_name="cr3bp_dynamics")
            : modelspace::Model(pnt, schedule_slot, m_name) { }
        CR3BPDynamicsModel(modelspace::SimulationExecutive &e, int schedule_slot=0, const std::string &m_name="cr3bp_dynamics")
            : modelspace::Model(e, schedule_slot, m_name) { }
        virtual ~CR3BPDynamicsModel() {}
 
 
    protected:
        int start();
        int execute();
 
        std::array<double, 6> _input_states;
        std::array<double, 6> _rates;
        CR3BPDynamics _dynamics;
        CartesianVector3D _tmp;
    };
}
 
#endif