StarTracker.h

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/*
Star Tracker model header file
 
Author: Alex Reynolds
*/
 
#ifndef MODELS_SENSORS_STAR_TRACKER_H
#define MODELS_SENSORS_STAR_TRACKER_H
 
#include "core/macros.h"
#include "simulation/Model.h"
#include "six_dof_dynamics/Euler321.hpp"
#include "six_dof_dynamics/Quaternion.hpp"
#include "six_dof_dynamics/DCM.hpp"
#include "six_dof_dynamics/Frame.hpp"
#include "models/support/BiasNoiseModel.h"
#include "monitors/RateMonitor.h"
 
namespace modelspace {
 
    /**
     * @brief   Star Tracker Model
     * 
     * This model represents a simple star tracker which may be parameterized
     * with a given bias, noise, and rate. It measures the attitude of the 
     * star tracker frame, which is internally configured, relative to 
     * an externally assigned reference frame. 
     * 
     * Author: Alex Reynolds <alex.reynolds@attx.tech>
    */
    class StarTracker : public Model {
    public:
        // Model params
        //         NAME                     TYPE                    DEFAULT VALUE
        START_PARAMS
            /** The bias in measurement output described as a 3-2-1 Euler angle sequence, with angles
             *  in RADIANS. This parameter may account for a number of factors, including misalignment,
             *  measurement bias, etc. Default is no bias. */
            SIGNAL(bias,                    Euler321D,              Euler321D({0.0, 0.0, 0.0}))
            /** The one-sigma gaussian noise in measurement output described as a 3-2-1 Euler angle sequence, 
             *  with angles in RADIANS. Default is no noise. */
            SIGNAL(gaussian_noise,          Euler321D,              Euler321D({0.0, 0.0, 0.0}))
            /** The vehicle frame relative to which the star tracker is mounted and aligned. This is most
             *  typically the body frame of a spacecraft or other vehicle. mount_position__mf and mount_alignment__mf
             *  are described relative to this frame. */
            SIGNAL(mount_frame,             FrameD*,                nullptr)
            /** The position of the star tracker in the mount frame, represented in the default simulation
             *  unit (meters by default. pretty much always meters) */
            SIGNAL(mount_position__mf,      CartesianVector3D,      CartesianVector3D({0.0, 0.0, 0.0}))
            /** The alignment of the star tracker relative to the mount frame */
            SIGNAL(mount_alignment_mf,      QuaternionD,            QuaternionD({1.0, 0.0, 0.0, 0.0}))
            /** The reference frame relative to which all star tracker measurements will be returned.
             *  If a reference frame is not set, all star tracker measurements will be returned relative
             *  to the simulation root frame. */
            SIGNAL(reference_frame,         FrameD*,                nullptr)
            /** The rate at which the star tracker generates an output, in hertz. Setting this value
             *  to 0 forces the star tracker to output at the simulation rate. */
            SIGNAL(rate_hz,                 int,                    0)
            /** Value to seed the internal RNG for this model. */
            SIGNAL(seed_value,              int,                    0)
        END_PARAMS
 
        // Model inputs
        //         NAME                     TYPE                    DEFAULT VALUE
        START_INPUTS
 
        END_INPUTS
 
        // Model outputs
        //         NAME                     TYPE                    DEFAULT VALUE
        START_OUTPUTS
            /** The measurement output quaternion produced by the star tracker describing the 
             *  orientation of the star tracker "sensor frame" relative to the reference frame plus
             *  appropriate bias, noise, and rate limiting. */
            SIGNAL(meas_quat_sf_ref,        QuaternionD,            QuaternionD({1.0, 0.0, 0.0, 0.0}))
            /** The "perfect" output quaternion produced by the star tracker describing the 
             *  orientation of the star tracker "sensor frame" relative to the reference frame.  This parameter
             *  is informational and free from error. */
            SIGNAL(perfect_quat_sf_ref,     QuaternionD,            QuaternionD({1.0, 0.0, 0.0, 0.0}))
        END_OUTPUTS
 
        /// @brief Accessor for the sensor's frame
        clockwerk::DataIO<FrameD*> sensor_frame = clockwerk::DataIO<FrameD*>(this, "sensor_frame", &_sensor_frame);
 
        /// @brief Accessor for the internal bias and noise model
        /// @return Pointer to the bias noise model
        modelspace::BiasNoiseModel* biasNoiseModel() {return &_sensor_bias_noise;}
 
        /// @brief Accessor for the internal rate monitor model
        /// @return Pointer to the rate monitor model
        modelspace::RateMonitor* rateMonitor() {return &_rate_monitor;}
 
        // Model-specific implementations of startup and derivative
        StarTracker(Model &pnt, const std::string &m_name="star_tracker");
        StarTracker(SimulationExecutive &e, const std::string &m_name="star_tracker");
        StarTracker(Model &pnt, int schedule_slot, const std::string &m_name="star_tracker");
        StarTracker(SimulationExecutive &e, int schedule_slot, const std::string &m_name="star_tracker");
        virtual ~StarTracker() {}
    protected:
        int start();
        int execute();
 
        /// @brief Function to configure sensor -- runs in all constructors
        void _configureInternal();
 
        /// @brief The sensor frame in which all measurements will be taken
        FrameD _sensor_frame;
 
        /// @brief The bias and noise model for sensor output.
        BiasNoiseModel _sensor_bias_noise;
 
        /// @brief Rate monitor to control the rate at which the sensor runs
        RateMonitor _rate_monitor;
 
        // Temporary DCM to hold temporary attitude calculations
        DCMD _tmp_dcm;
 
        // Internal variable to hold full bias and noise
        Euler321D _total_error;
    };
 
}
 
#endif