Struct Attitude 

pub struct Attitude(/* private fields */);

Vehicle attitude: the rotation from Body to Ned.

Equation (7). Hamilton convention, crossing the API as a Quaternion, whose fields name the components. Each constructor normalizes what it is given; a zero or non-finite quaternion comes out non-finite, and Eskf::initialize_from refuses it as InitError::NotFinite.

Every constructor names the convention it takes, and there is no From<Quaternion>, for the reason the module docs give for keeping From<[f32; 3]> off the framed vectors: .into() would claim body-to-NED for a quaternion that is a stored inverse or an ENU one. A seed is where that costs most, because it is the one input with no residual to expose it: the filter runs on an attitude wrong by a frame, reports Status::Healthy if the seed covariance was confident, and nothing gates. How wrong depends on the attitude — the level case is a half turn, which is why a level bench check is the one that cannot find it.

Implementations

impl Attitude

pub fn level() -> Self

Level and pointing north.

pub fn from_body_to_ned(q: Quaternion) -> Self

Wrap a quaternion that already rotates body FRD to NED. Equation (7).

The seed path from either production autopilot, and it converts nothing: PX4’s vehicle_attitude.q is the “rotation from the FRD body frame to the NED earth frame”, Hamilton and scalar-first (msg/versioned/VehicleAttitude.msg:2,10), and ArduPilot publishes AP_AHRS::get_quat_body_to_ned (libraries/AP_AHRS/AP_AHRS.h:672). from_flu_to_nwu maps fusion-ahrs’s three conventions onto these constructors, Convention::Ned included.

Read at PX4-Autopilot c4e4ef98 (v1.18.0-beta1) and ardupilot 368dc0c4.

pub fn from_ned_to_body(q: Quaternion) -> Self

Invert a quaternion that rotates NED to body FRD.

Storing the inverse — the direction-cosine matrix that takes a navigation vector into the body frame — is a common convention, and it is the mistake no other check reaches. An inverted attitude is finite, is a unit quaternion, and is identity wherever the true one is, so it survives every gate and every static test; it differs only in the sign of every rotation the vehicle actually has.

pub fn from_flu_to_enu(q: Quaternion) -> Self

Convert a quaternion that rotates body FLU to ENU, the ROS REP 103 pair.

Two-sided, because both frames differ: q_{NED←FRD} = r_nav ⊗ q ⊗ r_body⁻¹, where r_nav is q_{NED←ENU} and r_body is q_{FRD←FLU}. Rotating only the navigation frame is the half-applied form, and it is not obviously wrong: it reports the same heading as this one and the vehicle upside down, so a level bench check that reads a compass agrees with it.

pub fn from_flu_to_nwu(q: Quaternion) -> Self

Convert a quaternion that rotates body FLU to NWU, as Madgwick-family filters report it.

fusion-ahrs is the one to hand: its quaternion rotates the sensor frame into the earth frame, its default Convention::Nwu puts north, west, up on the earth axes, and a level sensor then reads gravity on +z, which is an FLU body. Convention::Enu is from_flu_to_enu and Convention::Ned is from_body_to_ned.

Two-sided for the reason from_flu_to_enu is. Both halves are the same half turn here, so the conversion is a conjugation and a vehicle that is only rolled comes through unchanged — a second attitude that cannot tell a conversion from no conversion at all.

pub fn body_to_ned(self) -> Quaternion

The quaternion that rotates body FRD to NED: the convention from_body_to_ned takes, and what PX4 and ArduPilot publish.

pub fn ned_to_body(self) -> Quaternion

The quaternion that rotates NED to body FRD: the inverse of from_ned_to_body, for a consumer that stores the direction-cosine matrix taking navigation vectors into the body.

pub fn flu_to_enu(self) -> Quaternion

The quaternion that rotates body FLU to ENU, for ROS (nav_msgs/Odometry, sensor_msgs/Imu): the inverse of from_flu_to_enu.

Two-sided on the way out for the reason it is on the way in, q = r_nav⁻¹ ⊗ q_{NED←FRD} ⊗ r_body; rotating the navigation frame alone publishes the right heading and the vehicle upside down.

pub fn flu_to_nwu(self) -> Quaternion

The quaternion that rotates body FLU to NWU, as Madgwick-family filters report it: the inverse of from_flu_to_nwu.

pub fn euler_angles(self) -> (f32, f32, f32)

Roll, pitch, yaw in radians, from the ZYX sequence R = Rz(yaw) Ry(pitch) Rx(roll).

Trait Implementations

impl Clone for Attitude

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Attitude

impl Debug for Attitude

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Attitude

fn default() -> Self

Returns the “default value” for a type.

impl Format for Attitude

Available on crate feature defmt only.

The quaternion’s four components, scalar first, rather than nalgebra’s own Format, which would need its defmt feature and a second optional dependency edge to name it.

fn format(&self, f: Formatter<'_>)

Writes the defmt representation of self to fmt.

impl PartialEq for Attitude

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Attitude