insMotionOrientation

Motion model for 3-D orientation estimation

Since R2022a

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

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

Create insMotionOrientation for Use in insEKF

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: [7×1 double]
         StateCovariance: [7×7 double]
    AdditiveProcessNoise: [7×7 double]
             MotionModel: [1×1 insMotionOrientation]
                 Sensors: {}
             SensorNames: {1×0 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:

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

where:

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

• ω = (0, ω_x, ω_y, ω_z) is the angular velocity of the platform, expressed in the body frame.

Version History

Introduced in R2022a