Crate eskf[][src]

Error State Kalman Filter (ESKF)

An Error State Kalman Filter is a navigation filter based on regular Kalman filters, more specifically Extended Kalman Filters, that model the “error state” of the system instead of modelling the movement of the system.

The navigation filter is used to track position, velocity and orientation of an object which is sensing its state through an Inertial Measurement Unit (IMU) and some means of observing the true state of the filter such as GPS, LIDAR or visual odometry.


use eskf;
use nalgebra::{Vector3, Point3};
use std::time::Duration;

// Create a default filter, modelling a perfect IMU without drift
let mut filter = eskf::Builder::new().build();
// Read measurements from IMU
let imu_acceleration = Vector3::new(0.0, 0.0, -9.81);
let imu_rotation = Vector3::zeros();
// Tell the filter what we just measured
filter.predict(imu_acceleration, imu_rotation, Duration::from_millis(1000));
// Check the new state of the filter
// filter.position or filter.velocity...
// ...
// After some time we get an observation of the actual state
    Point3::new(0.0, 0.0, 0.0),
        .expect("Filter update failed");
// Since we have supplied an observation of the actual state of the filter the states have now
// been updated. The uncertainty of the filter is also updated to reflect this new information.



Builder for ESKF


Error State Kalman Filter



Potential errors raised during operations

Type Definitions


Time delta as a duration, used when std is available


Helper definition to make it easier to work with errors