GNC App for performing the magnetometer measurement update step of an EKF when a 3-axis magnetometer is available to report the local magnetic field vector. This app implements the EKF measurement correction step by comparing the measured magnetic field in the magnetometer frame to the expected magnetic field derived from an internal model (e.g., WMM, IGRF, lookup table) and the current state estimate. More...

#include <MagUpdate.h>

Inheritance diagram for warpos::MagUpdate:

[legend]

Classes
struct	Params
struct	Inputs
struct	Outputs

Public Member Functions
	MagUpdate (FlightExecutive &executive)
virtual	~MagUpdate ()
int16	activate () override
	Activate the app. The app will step when active.
int16	deactivate () override
	Deactivate the app. The app will not step when deactivated.
int16	command (uint16 apid, uint8 *buffer, uint16 size) override
	Process commands issued to the app.
inertial_nav::MagMeasVector	getResidual ()
	Getter function to grab the internal residual.
Public Member Functions inherited from warpos::App
	App (FlightExecutive &executive, const char *name, uint16 apid, uint8 instance=0)
	Executive-based constructor for the task.
virtual	~App ()
	Destructor. Doesn't really do anything.
int16	startup ()
	Initialize the app. Should be called once before step.
int16	step ()
	Step the app by a single step. Maps params, inputs, etc. to outputs.
log_level_e	logLevel ()
	Get the log level set for the executive.
void	logLevel (log_level_e log_level)
	Set the executive log level.
bool	isStarted ()
	Return whether task startup has been run.
uint16	apid ()
	Get the apid for this app.
uint8 &	instance ()
	Get the instance of this app (used to differentiate between multiple instances of the same app).
Public Member Functions inherited from clockwerk::GraphTreeObject
	GraphTreeObject (const char gt_nme="", GraphTreeObject *storage_array=nullptr, uint32 storage_size=0)
	Name-based constructor for GraphTreeObject which will have no children by default.
virtual	~GraphTreeObject ()
	Destructor.
GraphTreeObject *	parent ()
	Functions to get object's parent/children.
GraphTreeObject **	children ()
GraphTreeObject *	childAtIndex (uint8 i) const
int16	parent (GraphTreeObject *new_parent)
	Function to assign the node's parent via pointer.
int16	parent (GraphTreeObject &new_parent)
	Function to assign the node's parent via reference.
uint8	nChildren () const
	Getters for number of children and descendants.
uint16	nDescendants () const
uint8	capacity () const
const char *	name () const
	Getter and setter for object name.
int16	name (const char *new_name)
uint8	rank ()
	Getter for the object rank.
int8	type ()
	Function to indicate type – -1 by default unless implemented downstream.
bool	loggable ()
	Getter for object logability flag – note no setter because should only be set by this or a derived class in its definition.
GraphTreeObject *	getRootDataPointer ()
	Get the pointer to the highest object in the graph tree.
virtual int16	str (char *output, size_t size) const
	Get object represented as string.
virtual int16	fromStr (const char *val)
	Set value of graphtreeobject from string.

Public Attributes
Params	params = Params(this, "params")
Inputs	inputs = Inputs(this, "inputs")
Outputs	outputs = Outputs(this, "outputs")
Public Attributes inherited from warpos::App
clockwerk::DataIO< bool >	active = clockwerk::DataIO<bool>(this, "active", true)
	The active flag for the task – set to true by default.

Protected Member Functions
int16	start () override
int16	execute () override
Protected Member Functions inherited from clockwerk::GraphTreeObject
int16	_setStorage (GraphTreeObject **storage_array, uint8 storage_size)
	Getter for object's string address.
void	_recalculateDescendants ()
	Function to recursively re-calculate the number of descendants of a given node on the tree.
void	_recalculateRank ()
	Function to recursively re-calculate the rank of a given node on the tree.
int16	_addChild (GraphTreeObject *child)
	Function to decompose a string into a series of substrings via indexing.
int16	_removeChild (GraphTreeObject *child)
	Function to remove a child from the graph node's children.

Protected Attributes
PointingVectorMeasurements< inertial_nav::STATE_SIZE >	_measurements
	Reference variable to the internal Measurements.
EkfMeasurementUpdate< inertial_nav::STATE_SIZE, POINTING_MEASUREMENT_MEASUREMENT_VECTOR_ELEMENTS, POINTING_MEASUREMENT_OBSERVER_VECTOR_ELEMENTS >	_measUpdate
	Reference variable to the internal EkfMeasurementsUpdate.
std::array< floating_point, 3 >	_dummy3
	Dummy temporary array for swapping between std::array and clockwerk::CartesianVector.
std::array< floating_point, 4 >	_dummy4
inertial_nav::MagObsVector	_dummyObs
inertial_nav::StateVector	_state_input_array
	Temporary variables for the array input/outputs passed into the EkfMeasurementUpdate object.
inertial_nav::StateVector	_state_output_array
inertial_nav::MagObsVector	_state_observer_array
	Temporary variables for the array input/outputs passed into the EkfMeasurementUpdate object.
inertial_nav::MagMeasVector	_measurement_array
	Temporary variables for the array input/outputs passed into the EkfMeasurementUpdate object.
inertial_nav::MagMeasVector	_residual
clockwerk::CartesianVector< 3 >	_expected_mag_vec__pI
	Internal variables for the transformed measurements.
clockwerk::CartesianVector< 3 >	_mag_meas_vec__B
clockwerk::Quaternion	_unit_quat
	Temporary variable for unitizing a quaternion.
tlm_gnc_mag_update_state	_tlm_a_posteriori_state
	Packet to hold state after measurement incorporation.
clockwerk::Time	_repeat_check_time
	Variables to verify we are not processing stale measurements.
clockwerk::CartesianVector< 3 >	_repeat_check_meas
Protected Attributes inherited from warpos::App
FlightExecutive &	exc
	Override our executive to include the FlightExecutive instead.
int16	_error = 0
	Internal variable to track and return error on app step through.
uint16	_apid = 0
	Internal variable to hold the APID for this app.
bool	_is_started = false
	Flag indicating whether app has been started or not.
log_level_e	_local_log_level = log_level_e::LOG_WARNING
	The log level for this particular app.
GraphTreeObject *	_app_children [MAXIMUM_APP_CHILDREN]
	Local storage for App children so it can live on the graph tree.
uint8	_instance
	Instance number of this app. Used to differentiate between multiple instances of the same app.
Protected Attributes inherited from clockwerk::GraphTreeObject
GraphTreeObject *	_parent = nullptr
GraphTreeObject **	_children_ptr = nullptr
uint32	_max_num_children = 0
uint16	_num_descendants = 0
char	_name [MAXIMUM_NAME_CHARS] = ""
	String name for object.
uint8	_num_children = 0
	Number of direct children of the tree (not including the tree itself).
uint8	_rank = 0
int8	_graph_tree_type = BASE_GRAPH_TREE
	Variable to store graph tree object type.
bool	_loggable = false
	Variable to indicate whether the selected object is loggable. Set to false by default.
uint32	_index = 0
	Index pointing to the next write location for the graph tree children.

Detailed Description

GNC App for performing the magnetometer measurement update step of an EKF when a 3-axis magnetometer is available to report the local magnetic field vector. This app implements the EKF measurement correction step by comparing the measured magnetic field in the magnetometer frame to the expected magnetic field derived from an internal model (e.g., WMM, IGRF, lookup table) and the current state estimate.

This update step is primarily used to improve the estimation of vehicle attitude, particularly in scenarios where gyroscope bias and drift can degrade the accuracy of dead-reckoning propagation. The method assumes that the magnetic field vector at the vehicle's location is known or can be reasonably approximated in a reference frame (e.g., ECEF or NED), and that the transformation between the magnetometer frame and the body frame is known.

Attention: See InertialNavigationDefinition.hpp for in depth description

TODO: Need to add params for magnetometer shapping ellipse or magnetometer bias

Author: James Tabony james.nosp@m..tab.nosp@m.ony@a.nosp@m.ttx..nosp@m.tech

Constructor & Destructor Documentation

◆ MagUpdate()

warpos::MagUpdate::MagUpdate ( FlightExecutive & executive )

◆ ~MagUpdate()

virtual warpos::MagUpdate::~MagUpdate ( )

inlinevirtual

Member Function Documentation

◆ activate()

int16 warpos::MagUpdate::activate ( )

overridevirtual

Activate the app. The app will step when active.

Returns: Flag indicating success/failure

Reimplemented from warpos::App.

◆ command()

int16 warpos::MagUpdate::command	(	uint16	apid,
		uint8 *	buffer,
		uint16	size )

overridevirtual

Process commands issued to the app.

Parameters

apid	The APID of the command sent
buffer	Pointer to the location of the buffer holding the command
size	The size of the command being sent

Returns: Flag indicating success/failure

Reimplemented from warpos::App.

◆ deactivate()

int16 warpos::MagUpdate::deactivate ( )

overridevirtual

Deactivate the app. The app will not step when deactivated.

Returns: Flag indicating success/failure

Reimplemented from warpos::App.

◆ execute()

int16 warpos::MagUpdate::execute ( )

overrideprotectedvirtual

Reimplemented from warpos::App.

◆ getResidual()

inertial_nav::MagMeasVector warpos::MagUpdate::getResidual ( )

inline

Getter function to grab the internal residual.

Returns: Measurement residual

◆ start()

int16 warpos::MagUpdate::start ( )

overrideprotectedvirtual

Reimplemented from warpos::App.

Member Data Documentation

◆ _dummy3

std::array<floating_point, 3> warpos::MagUpdate::_dummy3

protected

Dummy temporary array for swapping between std::array and clockwerk::CartesianVector.

◆ _dummy4

std::array<floating_point, 4> warpos::MagUpdate::_dummy4

protected

◆ _dummyObs

inertial_nav::MagObsVector warpos::MagUpdate::_dummyObs

protected

◆ _expected_mag_vec__pI

clockwerk::CartesianVector<3> warpos::MagUpdate::_expected_mag_vec__pI

protected

Internal variables for the transformed measurements.

◆ _mag_meas_vec__B

clockwerk::CartesianVector<3> warpos::MagUpdate::_mag_meas_vec__B

protected

◆ _measUpdate

EkfMeasurementUpdate<inertial_nav::STATE_SIZE, POINTING_MEASUREMENT_MEASUREMENT_VECTOR_ELEMENTS, POINTING_MEASUREMENT_OBSERVER_VECTOR_ELEMENTS> warpos::MagUpdate::_measUpdate

protected

Reference variable to the internal EkfMeasurementsUpdate.

◆ _measurement_array

inertial_nav::MagMeasVector warpos::MagUpdate::_measurement_array

protected

Temporary variables for the array input/outputs passed into the EkfMeasurementUpdate object.

◆ _measurements

PointingVectorMeasurements<inertial_nav::STATE_SIZE> warpos::MagUpdate::_measurements

protected

Reference variable to the internal Measurements.

◆ _repeat_check_meas

clockwerk::CartesianVector<3> warpos::MagUpdate::_repeat_check_meas

protected

◆ _repeat_check_time

clockwerk::Time warpos::MagUpdate::_repeat_check_time

protected

Variables to verify we are not processing stale measurements.

◆ _residual

inertial_nav::MagMeasVector warpos::MagUpdate::_residual

protected

◆ _state_input_array

inertial_nav::StateVector warpos::MagUpdate::_state_input_array

protected

Temporary variables for the array input/outputs passed into the EkfMeasurementUpdate object.

◆ _state_observer_array

inertial_nav::MagObsVector warpos::MagUpdate::_state_observer_array

protected

Temporary variables for the array input/outputs passed into the EkfMeasurementUpdate object.

◆ _state_output_array

inertial_nav::StateVector warpos::MagUpdate::_state_output_array

protected

◆ _tlm_a_posteriori_state

tlm_gnc_mag_update_state warpos::MagUpdate::_tlm_a_posteriori_state

protected

Packet to hold state after measurement incorporation.

◆ _unit_quat

clockwerk::Quaternion warpos::MagUpdate::_unit_quat

protected

Temporary variable for unitizing a quaternion.

◆ inputs

Inputs warpos::MagUpdate::inputs = Inputs(this, "inputs")

◆ outputs

Outputs warpos::MagUpdate::outputs = Outputs(this, "outputs")

◆ params

Params warpos::MagUpdate::params = Params(this, "params")

The documentation for this class was generated from the following files:

/Users/mickey/Documents/Projects/warptwin/warpos/src/apps/gnc/InertialNavigationEKF/MagUpdate.h
/Users/mickey/Documents/Projects/warptwin/warpos/src/apps/gnc/InertialNavigationEKF/MagUpdate.cpp

Classes

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ MagUpdate()

◆ ~MagUpdate()

Member Function Documentation

◆ activate()

◆ command()

◆ deactivate()

◆ execute()

◆ getResidual()

◆ start()

Member Data Documentation

◆ _dummy3

◆ _dummy4

◆ _dummyObs

◆ _expected_mag_vec__pI

◆ _mag_meas_vec__B

◆ _measUpdate

◆ _measurement_array

◆ _measurements

◆ _repeat_check_meas

◆ _repeat_check_time

◆ _residual

◆ _state_input_array

◆ _state_observer_array

◆ _state_output_array

◆ _tlm_a_posteriori_state

◆ _unit_quat

◆ inputs

◆ outputs

◆ params