TwoAxisPointingGuidance.h

/******************************************************************************
* Copyright (c) ATTX LLC 2024. All Rights Reserved.
*
* This software and associated documentation (the "Software") are the 
* proprietary and confidential information of ATTX, LLC. The Software is 
* furnished under a license agreement between ATTX and the user organization 
* and may be used or copied only in accordance with the terms of the agreement.
* Refer to 'license/attx_license.adoc' for standard license terms.
*
* EXPORT CONTROL NOTICE: THIS SOFTWARE MAY INCLUDE CONTENT CONTROLLED UNDER THE
* INTERNATIONAL TRAFFIC IN ARMS REGULATIONS (ITAR) OR THE EXPORT ADMINISTRATION 
* REGULATIONS (EAR99). No part of the Software may be used, reproduced, or 
* transmitted in any form or by any means, for any purpose, without the express 
* written permission of ATTX, LLC.
******************************************************************************/
/*
Triad method guidance task header file 

Author: Alex Jackson
*/

#ifndef APPS_TWO_AXIS_POINTING_GUIDANCE_H
#define APPS_TWO_AXIS_POINTING_GUIDANCE_H

#include "flight/App.h"
#include "flight/FlightExecutive.h"

#include "core/CartesianVector.hpp"
#include "dynamics/Quaternion.h"
#include "core/mathmacros.h"

#include "telemetry/tlm_TwoAxisPointingGuidance.h"

namespace warpos {

    /**
     * @brief   Two-axis constrained pointing guidance method guidance
     * 
     * This task applies a simple pointing guidance based on the Triad method
     * for attitude determination. In this approach, two body axes are selected,
     * along with desired vectors in the reference frame to which they should
     * point. The task calculates the attitude body/reference which fully meets
     * the primary pointing constraint and attempts a best effort at the secondary
     * pointing constraint.
    */
    class TwoAxisPointingGuidance : public App {
    public:
        // Model inputs
        //         NAME                     TYPE                    DEFAULT VALUE
        START_INPUTS
            /** The body axis vector which will be pointed to desired_primary */
            SIGNAL(current_primary_body,     CartesianVector3,       CartesianVector3({1.0, 0.0, 0.0}))
            /** The desired primary vector expressed in an arbitrary frame */
            SIGNAL(desired_primary,          CartesianVector3,        CartesianVector3({1.0, 0.0, 0}))
            /** The body axis vector which will be pointed to desired_secondary */
            SIGNAL(current_secondary_body,    CartesianVector3,      CartesianVector3({0.0, 1.0, 0.0}))
            /** The desired secondary vector expressed in an arbitrary frame */
            SIGNAL(desired_secondary,        CartesianVector3,       CartesianVector3({0.0, 1.0, 0.0}))
        END_INPUTS

        // Model outputs
        //         NAME                     TYPE                    DEFAULT VALUE
        START_OUTPUTS
            /** The desired attitude of the s/c body with respect to a reference frame that the desired primary and secondary were expressed in */
            SIGNAL(quat_body_ref,           clockwerk::Quaternion,  clockwerk::Quaternion({1.0, 0.0, 0.0, 0.0}))
        END_OUTPUTS 

        TwoAxisPointingGuidance(FlightExecutive &executive);

        virtual ~TwoAxisPointingGuidance() {};
    
        /// @brief Activate the app. The app will step when active.
        /// @return Flag indicating success/failure
        int16 activate() override;

        /// @brief Deactivate the app. The app will not step when deactivated
        /// @return Flag indicating success/failure
        int16 deactivate() override;

        /// @brief Process commands issued to the app
        /// @param apid The APID of the command sent
        /// @param buffer Pointer to the location of the buffer holding the command
        /// @param size The size of the command being sent
        /// @return Flag indicating success/failure
        int16 command(uint16 apid, uint8* buffer, uint16 size) override;

    protected:
        int16 start() override;
        int16 execute() override;

        // Local vectors to establish DCM -- here for speed
        CartesianVector3 _body_triadx;
        CartesianVector3 _body_triady;
        CartesianVector3 _body_triadz;
        CartesianVector3 _ref_triadx;
        CartesianVector3 _ref_triady;
        CartesianVector3 _ref_triadz;

        /// Local variables for DCM body/ref to Quaternion conversion
        clockwerk::DCM _dcm_body_ref;
        clockwerk::Quaternion _quat_body_ref;

        // Internal variables for DCMs defined by pointing targets
        clockwerk::DCM _body_triad;
        clockwerk::DCM _ref_triad;

        // Telemetry packet for packing
        tlm_gnc_two_axis_pnt_data _tlm_pkt;
    };

}

#endif