Class inertialsim::sensors::INS¶

ClassList > inertialsim > sensors > INS

INS sensor simulation.More...

#include <ins.h>

Public Functions¶

Type	Name
	INS (const INSModel & model, const INSSpecification & specification, std::optional< uint64_t > seed=0, INSSimulationMode mode=INSSimulationMode::BATCH) Construct an INS .
std::optional< INSData >	Initialize (const std::optional< geodesy::GlobalPose > & pose=std::nullopt, const std::optional< geometry::Vector > & angular_rate=std::nullopt, const std::optional< geometry::Vector > & specific_force=std::nullopt) Initialize the INS with a GlobalPose.
void	Reset (const std::optional< geometry::Rotation > & attitude=std::nullopt, const std::optional< geodesy::Coordinates > & position=std::nullopt, const std::optional< geometry::Vector > & velocity=std::nullopt) Reset the INS state.
INSData	Simulate (const geometry::Vector & angular_rate, const geometry::Vector & specific_force) Simulate INS measurements fromIMU inputs.
INSData	Simulate (const Measurement & angular_rate, const Measurement & specific_force) Simulate INS measurements fromMeasurement inputs.
bool	initialized () const Check if the INS is initialized.
INSSimulationMode	mode () const Get the simulation mode.
const INSModel &	model () const Get the INS model.
const std::mt19937_64 &	rng () const Get the random number generator.
const INSSpecification &	specification () const Get the INS specification.
const INSState &	state () const Get the simulation state.

Protected Attributes¶

Type	Name
Eigen::Vector3d	earth_rate_
std::optional< geodesy::GeodeticDatum >	geodetic_datum_
std::shared_ptr< geodesy::Gravity >	gravity_model_
WhiteNoiseBuffer	gravity_noise_
bool	initialized_ = `false`
INSSimulationMode	mode_
INSModel	model_
InternalPose	pose_
std::mt19937_64	rng_
INSSpecification	specification_
INSState	state_
WhiteNoiseBuffer	time_jitter_
std::optional< geodesy::TopocentricDatum >	topocentric_datum_

Protected Functions¶

Type	Name
std::pair< Vector3D, Vector3D >	ApparentForces (const Vector3D & p, const Vector3D & v) Get Coriolis and centripetal forces.
geodesy::Coordinates	Coordinates (const Vector3D & p, const Timestamps & time) Convert Coordinates from internal position.
Vector3D	Gravity (const Vector3D & p, const Timestamps & time) Get gravity at a position.
std::tuple< Vector3D, Vector3D, Vector3D >	IncrementalPose (const Vector3D & angular_rate, const Vector3D & specific_force, const Timestamps & time) Compute incremental pose updates.
InternalPose	InitialConditions (const geodesy::GlobalPose & pose, const std::optional< geometry::Vector > & angular_rate, const std::optional< geometry::Vector > & specific_force) Set up initial conditions from GlobalPose.
std::tuple< RotationMatrixArray, Vector3D, Vector3D, Timestamps >	Integrate (const Vector3D & angular_rate, const Vector3D & specific_force, const Timestamps & time) Integrate the navigation equations.
std::pair< RotationMatrixArray, Vector3D >	IntegrateAttitude (const RotationMatrix & R0, const Vector3D & dphi, const Timestamps & time) Integrate attitude using rotation matrices.
std::pair< Vector3D, Vector3D >	IntegrateTranslation (const RotationMatrixArray & R, const Eigen::Vector3d & p0, const Eigen::Vector3d & v0, const Vector3D & dphi, const Vector3D & dzeta, const Vector3D & deta, const Timestamps & time) Integrate position and velocity.
void	SetFixedErrors () Set fixed errors (called at initialization).
INSData	SimulateDataInterface (const RotationMatrixArray & R, const Vector3D & p, const Vector3D & v, const Timestamps & time) Simulate data interface effects.
void	SimulateGravityNoise (Vector3D & gravity) Apply gravity noise.
void	SimulateGravityScaleFactor (Vector3D & gravity) Apply gravity scale factor.
void	SimulateInitialBias (InternalPose & pose, const RotationMatrix & geodetic_rotation) Apply initial condition bias.
void	SimulateInitialRandomError (InternalPose & pose, const RotationMatrix & geodetic_rotation) Apply initial condition random error.
void	SimulateTimeJitter (Timestamps & time) Apply time jitter.

Protected Static Functions¶

Type	Name
geometry::ExtendedPose::AlgebraArray	PoseRate (const geometry::ExtendedPose::AlgebraArray & pose, const Vector3D & omega, const Vector3D & asf) Calculate pose rate using SE(3) Lie algebra.
geometry::ExtendedPose::AlgebraArray	RK4 (const Vector3D & omega, const Vector3D & asf, const Timestamps & time) RK4 integration for navigation equations.
Vector3D	ScrollingRate (const geometry::ExtendedPose::AlgebraArray & pose, const Vector3D & phi_rate) Calculate scrolling rate (position rate derivative).

Detailed Description¶

INS integrates gyro and accelerometer data to produce attitude (orientation), position, and velocity outputs. The class supports both batch and real-time simulation modes.

Public Functions Documentation¶

function INS¶

Construct an INS .

inertialsim::sensors::INS::INS (
    const INSModel & model,
    const INSSpecification & specification,
    std::optional< uint64_t > seed=0,
    INSSimulationMode mode=INSSimulationMode::BATCH
)

Parameters:

model INS model options.
specification INS specification.
seed Random number generator seed (0 for random).
mode Simulation mode (batch or real-time).

function Initialize¶

Initialize the INS with a GlobalPose.

std::optional< INSData > inertialsim::sensors::INS::Initialize (
    const std::optional< geodesy::GlobalPose > & pose=std::nullopt,
    const std::optional< geometry::Vector > & angular_rate=std::nullopt,
    const std::optional< geometry::Vector > & specific_force=std::nullopt
)

Sets the initial attitude, position, and velocity. For real-time mode, also requires initial angular rate and specific force.

Parameters:

pose Initial pose (nullopt for default local frame).
angular_rate Initial angular rate (for real-time mode only).
specific_force Initial specific force (for real-time mode only).

Returns:

INSData with initial pose (only in real-time mode).

function Reset¶

Reset the INS state.

void inertialsim::sensors::INS::Reset (
    const std::optional< geometry::Rotation > & attitude=std::nullopt,
    const std::optional< geodesy::Coordinates > & position=std::nullopt,
    const std::optional< geometry::Vector > & velocity=std::nullopt
)

Parameters:

attitude New attitude (nullopt to keep current).
position New position (nullopt to keep current).
velocity New velocity (nullopt to keep current).

function Simulate [½]¶

Simulate INS measurements fromIMU inputs.

INSData inertialsim::sensors::INS::Simulate (
    const geometry::Vector & angular_rate,
    const geometry::Vector & specific_force
)

Integrates angular rate and specific force to produce attitude, position, and velocity outputs.

Parameters:

angular_rate Angular rate of the INS relative to inertial space.
specific_force Specific force experienced by the INS.

Returns:

INSData containing simulated measurements.

Exception:

std::runtime_error if INS is not initialized.
std::invalid_argument if inputs are invalid.

function Simulate [2/2]¶

Simulate INS measurements fromMeasurement inputs.

INSData inertialsim::sensors::INS::Simulate (
    const Measurement & angular_rate,
    const Measurement & specific_force
)

Parameters:

angular_rate Angular rate measurement.
specific_force Specific force measurement.

Returns:

INSData containing simulated measurements.

function initialized¶

Check if the INS is initialized.

inline bool inertialsim::sensors::INS::initialized () const

Returns:

True if initialized.

function mode¶

Get the simulation mode.

inline INSSimulationMode inertialsim::sensors::INS::mode () const

Returns:

Simulation mode.

function model¶

Get the INS model.

inline const INSModel & inertialsim::sensors::INS::model () const

Returns:

Reference to the model.

function rng¶

Get the random number generator.

inline const std::mt19937_64 & inertialsim::sensors::INS::rng () const

Returns:

Reference to the RNG.

function specification¶

Get the INS specification.

inline const INSSpecification & inertialsim::sensors::INS::specification () const

Returns:

Reference to the specification.

function state¶

Get the simulation state.

const INSState & inertialsim::sensors::INS::state () const

Returns the simulation state including all internal sensor parameters required to replicate the simulated measurement outputs.

Returns:

Reference to the INS state.

Exception:

std::runtime_error if INS is not initialized.

Protected Attributes Documentation¶

variable earth_rate_¶

Eigen::Vector3d inertialsim::sensors::INS::earth_rate_;

variable geodetic_datum_¶

std::optional<geodesy::GeodeticDatum> inertialsim::sensors::INS::geodetic_datum_;

variable gravity_model_¶

std::shared_ptr<geodesy::Gravity> inertialsim::sensors::INS::gravity_model_;

variable gravity_noise_¶

WhiteNoiseBuffer inertialsim::sensors::INS::gravity_noise_;

variable initialized_¶

bool inertialsim::sensors::INS::initialized_;

variable mode_¶

INSSimulationMode inertialsim::sensors::INS::mode_;

variable model_¶

INSModel inertialsim::sensors::INS::model_;

variable pose_¶

InternalPose inertialsim::sensors::INS::pose_;

variable rng_¶

std::mt19937_64 inertialsim::sensors::INS::rng_;

variable specification_¶

INSSpecification inertialsim::sensors::INS::specification_;

variable state_¶

INSState inertialsim::sensors::INS::state_;

variable time_jitter_¶

WhiteNoiseBuffer inertialsim::sensors::INS::time_jitter_;

variable topocentric_datum_¶

std::optional<geodesy::TopocentricDatum> inertialsim::sensors::INS::topocentric_datum_;

Protected Functions Documentation¶

function ApparentForces¶

Get Coriolis and centripetal forces.

std::pair< Vector3D, Vector3D > inertialsim::sensors::INS::ApparentForces (
    const Vector3D & p,
    const Vector3D & v
)

function Coordinates¶

Convert Coordinates from internal position.

geodesy::Coordinates inertialsim::sensors::INS::Coordinates (
    const Vector3D & p,
    const Timestamps & time
)

function Gravity¶

Get gravity at a position.

Vector3D inertialsim::sensors::INS::Gravity (
    const Vector3D & p,
    const Timestamps & time
)

function IncrementalPose¶

Compute incremental pose updates.

std::tuple< Vector3D, Vector3D, Vector3D > inertialsim::sensors::INS::IncrementalPose (
    const Vector3D & angular_rate,
    const Vector3D & specific_force,
    const Timestamps & time
)

function InitialConditions¶

Set up initial conditions from GlobalPose.

InternalPose inertialsim::sensors::INS::InitialConditions (
    const geodesy::GlobalPose & pose,
    const std::optional< geometry::Vector > & angular_rate,
    const std::optional< geometry::Vector > & specific_force
)

function Integrate¶

Integrate the navigation equations.

std::tuple< RotationMatrixArray, Vector3D, Vector3D, Timestamps > inertialsim::sensors::INS::Integrate (
    const Vector3D & angular_rate,
    const Vector3D & specific_force,
    const Timestamps & time
)

function IntegrateAttitude¶

Integrate attitude using rotation matrices.

std::pair< RotationMatrixArray, Vector3D > inertialsim::sensors::INS::IntegrateAttitude (
    const RotationMatrix & R0,
    const Vector3D & dphi,
    const Timestamps & time
)

function IntegrateTranslation¶

Integrate position and velocity.

std::pair< Vector3D, Vector3D > inertialsim::sensors::INS::IntegrateTranslation (
    const RotationMatrixArray & R,
    const Eigen::Vector3d & p0,
    const Eigen::Vector3d & v0,
    const Vector3D & dphi,
    const Vector3D & dzeta,
    const Vector3D & deta,
    const Timestamps & time
)

function SetFixedErrors¶

Set fixed errors (called at initialization).

void inertialsim::sensors::INS::SetFixedErrors ()

function SimulateDataInterface¶

Simulate data interface effects.

INSData inertialsim::sensors::INS::SimulateDataInterface (
    const RotationMatrixArray & R,
    const Vector3D & p,
    const Vector3D & v,
    const Timestamps & time
)

function SimulateGravityNoise¶

Apply gravity noise.

void inertialsim::sensors::INS::SimulateGravityNoise (
    Vector3D & gravity
)

function SimulateGravityScaleFactor¶

Apply gravity scale factor.

void inertialsim::sensors::INS::SimulateGravityScaleFactor (
    Vector3D & gravity
)

function SimulateInitialBias¶

Apply initial condition bias.

void inertialsim::sensors::INS::SimulateInitialBias (
    InternalPose & pose,
    const RotationMatrix & geodetic_rotation
)

function SimulateInitialRandomError¶

Apply initial condition random error.

void inertialsim::sensors::INS::SimulateInitialRandomError (
    InternalPose & pose,
    const RotationMatrix & geodetic_rotation
)

function SimulateTimeJitter¶

Apply time jitter.

void inertialsim::sensors::INS::SimulateTimeJitter (
    Timestamps & time
)

Protected Static Functions Documentation¶

function PoseRate¶

Calculate pose rate using SE(3) Lie algebra.

static geometry::ExtendedPose::AlgebraArray inertialsim::sensors::INS::PoseRate (
    const geometry::ExtendedPose::AlgebraArray & pose,
    const Vector3D & omega,
    const Vector3D & asf
)

Computes the Lie algebra differential equations using the SE(3) group jacobian and the Savage scrolling rate.

Parameters:

pose N×9 matrix: [orientation(3), position(3), velocity(3)].
omega N×3 matrix: angular rate from gyros.
asf N×3 matrix: accelerometer specific force.

Returns:

N×9 matrix: pose rate [φ_rate(3), ζ_rate(3), η_rate(3)].

function RK4¶

RK4 integration for navigation equations.

static geometry::ExtendedPose::AlgebraArray inertialsim::sensors::INS::RK4 (
    const Vector3D & omega,
    const Vector3D & asf,
    const Timestamps & time
)

Integrates over three samples at a time using the RK4 method, specialized for the inertial navigation problem. The initial state is always zero. Divides time into overlapping 3-sample sets and integrates each set, producing fewer outputs than inputs.

Parameters:

omega N×3 matrix: angular rate from gyros.
asf N×3 matrix: accelerometer specific force.
time N×1 vector: time samples.

Returns:

(N-1)/2 × 9 matrix: incremental pose changes [dφ, dζ, dη].

function ScrollingRate¶

Calculate scrolling rate (position rate derivative).

static Vector3D inertialsim::sensors::INS::ScrollingRate (
    const geometry::ExtendedPose::AlgebraArray & pose,
    const Vector3D & phi_rate
)

Computes the position increment rate accounting for scrolling effects from rotation-translation coupling in strapdown navigation.

Parameters:

pose N×9 matrix: [orientation(3), position(3), velocity(3)].
phi_rate N×3 matrix: orientation rate (time derivative).

Returns:

N×3 matrix: position rate.

The documentation for this class was generated from the following file cpp/include/inertialsim/sensors/ins.h