Struct AttitudeVariance 

pub struct AttitudeVariance {
    pub tilt_north: f32,
    pub tilt_east: f32,
    pub heading: f32,
}

How uncertain the attitude is about each navigation axis, in radians squared: tilt about north and east, heading about down.

The covariance cannot be read for these directly. Its attitude block is the covariance of δθ, a rotation vector in body axes (equations (2)–(4)), and (36) states the navigation-frame rotation it stands for as R(q̂) δθ. So the body x and y diagonal is tilt, and z heading, only while the vehicle is level: at 90° of pitch body x is vertical, and P[δθ_x] is the heading’s variance. These are the diagonal of R(q̂) P_θθ R(q̂)ᵀ, which holds at any attitude, and which is what PX4 publishes too — getTiltVariance and getYawVar read the same components of its navigation-frame covariance (src/modules/ekf2/EKF/ekf_helper.cpp:938-947 at c4e4ef98e9).

heading is exactly H P Hᵀ for the heading Jacobian of (36), whose row is the third of R(q̂): a heading source and this struct agree on what heading uncertainty is.

Fields

tilt_north: f32

About north: the tilt a roll reads while the vehicle faces north.

tilt_east: f32

About east: the tilt a pitch reads while the vehicle faces north.

heading: f32

About down.

Implementations

impl AttitudeVariance

pub fn to_enu(self) -> [f32; 3]

The three variances about east, north and up, the axes ROS’s ENU frame orders a nav_msgs/Odometry orientation covariance in: the horizontal pair swapped, and the sign of an axis, which a variance does not carry, dropped.

Trait Implementations

impl Clone for AttitudeVariance

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 AttitudeVariance

impl Debug for AttitudeVariance

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

Formats the value using the given formatter.

impl Default for AttitudeVariance

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for AttitudeVariance

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for AttitudeVariance