FlightTasks.hpp

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/**
 * @file flight_taks.h
 *
 * Library class to hold and manage all implemented flight task instances
 *
 * @author Matthias Grob <maetugr@gmail.com>
 */

#pragma once

#include "FlightTask.hpp"
#include "FlightTasks_generated.hpp"
#include <lib/weather_vane/WeatherVane.hpp>
#include <uORB/PublicationQueued.hpp>
#include <uORB/Subscription.hpp>
#include <uORB/topics/vehicle_command_ack.h>
#include <uORB/topics/vehicle_command.h>

#include <new>

enum class FlightTaskError : int {
    NoError = 0,
    InvalidTask = -1,
    ActivationFailed = -2
};

class FlightTasks
{
public:
    FlightTasks();

    ~FlightTasks()
    {
        if (_current_task.task) {
            _current_task.task->~FlightTask();
        }
    }

    /**
     * Call regularly in the control loop cycle to execute the task
     * @return true on success, false on error
     */
    bool update();

    /**
     * Get the output data from the current task
     * @return output setpoint, to be executed by position control
     */
    const vehicle_local_position_setpoint_s getPositionSetpoint();

    /**
     * Get task dependent constraints
     * @return setpoint constraints that has to be respected by the position controller
     */
    const vehicle_constraints_s getConstraints();

    /**
     * Get landing gear position.
     * @return landing gear
     */
    const landing_gear_s getGear();

    /**
     * Get task avoidance desired waypoints
     * @return auto triplets in the mc_pos_control
     */
    const vehicle_trajectory_waypoint_s getAvoidanceWaypoint();

    /**
     * Get empty avoidance desired waypoints
     * @return empty triplets in the mc_pos_control
     */
    const vehicle_trajectory_waypoint_s &getEmptyAvoidanceWaypoint();

    /**
     * Switch to the next task in the available list (for testing)
     * @return 0 on success, <0 on error
     */
    FlightTaskError switchTask() { return switchTask(static_cast<int>(_current_task.index) + 1); }

    /**
     * Switch to a specific task (for normal usage)
     * @param task index to switch to
     * @return 0 on success, <0 on error
     */
    FlightTaskError switchTask(FlightTaskIndex new_task_index);
    FlightTaskError switchTask(int new_task_index);

    /**
     * Get the number of the active task
     * @return number of active task, -1 if there is none
     */
    int getActiveTask() const { return static_cast<int>(_current_task.index); }

    /**
     * Check if any task is active
     * @return true if a task is active, false if not
     */
    bool isAnyTaskActive() const { return _current_task.task; }

    /**
     * Call this whenever a parameter update notification is received (parameter_update uORB message)
     */
    void handleParameterUpdate();

    /**
     * Call this method to get the description of a task error.
     */
    const char *errorToString(const FlightTaskError error);

    /**
     * Sets an external yaw handler. The active flight task can use the yaw handler to implement a different yaw control strategy.
     */
    void setYawHandler(WeatherVane *ext_yaw_handler) {_current_task.task->setYawHandler(ext_yaw_handler);}

    /**
     *   This method will re-activate current task.
     */
    void reActivate();

    void updateVelocityControllerIO(const matrix::Vector3f &vel_sp, const matrix::Vector3f &thrust_sp) {_current_task.task->updateVelocityControllerIO(vel_sp, thrust_sp); }

private:

    /**
     * Union with all existing tasks: we use it to make sure that only the memory of the largest existing
     * task is needed, and to avoid using dynamic memory allocations.
     */
    TaskUnion _task_union; /**< storage for the currently active task */

    struct flight_task_t {
        FlightTask *task;
        FlightTaskIndex index;
    };
    flight_task_t _current_task = {nullptr, FlightTaskIndex::None};

    struct task_error_t {
        int error;
        const char *msg;
    };

    static constexpr int _numError = 3;
    /**
     * Map from Error int to user friendly string.
     */
    task_error_t _taskError[_numError] = {
        {static_cast<int>(FlightTaskError::NoError), "No Error"},
        {static_cast<int>(FlightTaskError::InvalidTask), "Invalid Task "},
        {static_cast<int>(FlightTaskError::ActivationFailed), "Activation Failed"}
    };

    /**
     * Check for vehicle commands (received via MAVLink), evaluate and acknowledge them
     */
    void _updateCommand();
    FlightTaskIndex switchVehicleCommand(const int command);

    uORB::Subscription _sub_vehicle_command{ORB_ID(vehicle_command)}; /**< topic handle on which commands are received */

    uORB::PublicationQueued<vehicle_command_ack_s>  _pub_vehicle_command_ack{ORB_ID(vehicle_command_ack)};

    int _initTask(FlightTaskIndex task_index);
};