# insMotionOrientation

Motion model for 3-D orientation estimation

## Description

The insMotionOrientation object models orientation-only platform motion assuming a constant angular velocity. Passing an insMotionOrientation object to an insEKF object enables the estimation of 3-D orientation and angular velocity. For details on the motion model, see Algorithms.

## Creation

### Description

example

model = insMotionOrientation creates an insMotionOrientation object. Passing the created model to an insEKF object enables the estimation of:

• The orientation quaternion from the navigation frame to the body frame.

• The angular velocity of the platform, expressed in the body frame.

## Examples

collapse all

Create an insMotionOrientation object and pass it to an insEKF object.

motionModel = insMotionOrientation
motionModel =
insMotionOrientation with no properties.

filter = insEKF(motionModel)
filter =
insEKF with properties:

State: [7x1 double]
StateCovariance: [7x7 double]
MotionModel: [1x1 insMotionOrientation]
Sensors: {}
SensorNames: {1x0 cell}
ReferenceFrame: 'NED'

Show the state maintained in the filter.

stateinfo(filter)
ans = struct with fields:
Orientation: [1 2 3 4]
AngularVelocity: [5 6 7]

## Algorithms

The insMotionOrientation object models the orientation-only motion of platforms. The state equation of the motion model is:

$\begin{array}{l}\stackrel{˙}{q}=\frac{1}{2}\omega q\\ \stackrel{˙}{\omega }=0\end{array}$

where:

• q = (q0, q1, q2, q3) is the quaternion from the navigation frame to the body frame.

• ω is the angular velocity of the platform, expressed in the body frame.

## Version History

Introduced in R2022a