# 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

### Syntax

``model = insMotionOrientation``

### 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] AdditiveProcessNoise: [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