Platform.pose

Pose of platform

Syntax

pse = pose(ptfm)

pse = pose(ptfm,type)

pse = pose(___,'CoordinateSystem',coordinate)

Description

pse = pose(ptfm) returns the estimated pose, pse, of the platform ptfm, in scenario coordinates. The platform must already exist in the tracking scenario. Add platforms to a scenario using the platform method. The pose is estimated by a pose estimator specified in the PoseEstimator property of the platform.

pse = pose(ptfm,type) specifies the type of the pose estimation as 'estimated' or 'true'.

pse = pose(___,'CoordinateSystem',coordinate) specifies the coordinate system of the pse output. You can only use this syntax when the IsEarthCentered property of the tracking scenario is set to true.

Examples

Create Earth Centered Scenario

Create a tracking scenario with a specified update rate.

scene = trackingScenario('IsEarthCentered',true,'UpdateRate',0.01);

Add an airplane in the scenario. The trajectory of the airplane changes in latitude and altitude.

plane = platform(scene,'Trajectory',geoTrajectory([-12.338,-71.349,10600;42.390,-71.349,0],[0 36000]));

Advance the tracking scenario and record the geodetic and Cartesian positions of the plane target.

positions = [];
while advance(scene)
    poseLLA = pose(plane,'CoordinateSystem','Geodetic');
    poseCart = pose(plane,'CoordinateSystem','Cartesian');
    positions = [positions;poseCart.Position];%#ok<AGROW> Allow the buffer to grow.
end

Visualize the trajectory in the ECEF frame.

figure()
km = 1000;
% Plot the trajectory.
plot3(positions(1,1)/km,positions(1,2)/km,positions(1,3)/km, 'b*');
hold on;
plot3(positions(end,1)/km,positions(end,2)/km,positions(end,3)/km, 'bo');
plot3(positions(:,1)/km,positions(:,2)/km,positions(:,3)/km,'b');

% Plot the Earth radial lines.
plot3([0 positions(1,1)]/km,[0 positions(1,2)]/km,[0 positions(1,3)]/km,'k:');
plot3([0 positions(end,1)]/km,[0 positions(end,2)]/km,[0 positions(end,3)]/km,'k:');
xlabel('x (km)'); ylabel('y (km)'); zlabel('z (km)');
legend('Start position','End position','Trajectory')

Input Arguments

ptfm — Scenario platform

Platform object

Scenario platform, specified as a Platform object. To create platforms, use the platform method.

type — Source of platform pose information

'estimated' (default) | 'true'

Source of platform pose information, specified as 'estimated' or 'true'. When set to 'estimated', the pose is estimated using the pose estimator specified in the PoseEstimator property of the tracking scenario. When 'true' is selected, the true pose of the platform is returned.

Example: 'true'

Data Types: char

coordinate — Coordinate system to report pose

'Cartesian' (default) | 'Geodetic'

Coordinate system to report pose, specified as:

• 'Cartesian' — Report poses using Cartesian coordinates in the Earth-Centered-Earth-Fixed coordinate frame.

• 'Geodetic' — Report positions using geodetic coordinates (latitude, longitude, and altitude). Report orientation, velocity, and acceleration in the local reference frame (North-East-Down by default) corresponding to the current waypoint.

.

You can only use this argument when the IsEarthCentered property of the tracking scenario is set to true.

Output Arguments

pse — Pose of platform

structure

Pose of platform, returned as a structure. Pose consists of the position, velocity, orientation, and angular velocity of the platform with respect to scenario coordinates. The returned structure has these fields:

Field	Description
PlatformID	Unique identifier for the platform, specified as a positive integer. This is a required field with no default value.
ClassID	User-defined integer used to classify the type of target, specified as a nonnegative integer. Zero is reserved for unclassified platform types and is the default value.
Position	Position of platform in scenario coordinates, specified as a real-valued 1-by-3 row vector. If the coordinateSystem argument is specified as 'Cartesian', the Position is the 3-element Cartesian position coordinates in meters. If the coordinateSystem argument is specified as 'Geodetic', the Position is the 3-element geodetic coordinates: latitude in degrees, longitude in degrees, and altitude in meters.
Velocity	Velocity of platform in scenario coordinates, specified as a real-valued 1-by-3 row vector. Units are meters per second. The default value is [0 0 0].
Acceleration	Acceleration of the platform in scenario coordinates, specified as a 1-by-3 row vector in meters per second squared. The default value is [0 0 0].
Orientation	Orientation of the platform with respect to the local scenario navigation frame, specified as a scalar quaternion or a 3-by-3 rotation matrix. Orientation defines the frame rotation from the local navigation coordinate system to the current platform body coordinate system. Units are dimensionless. The default value is quaternion(1,0,0,0) or a 3-by-3 identity matrix.
AngularVelocity	Angular velocity of the platform in scenario coordinates, specified as a real-valued 1-by-3 vector. The magnitude of the vector defines the angular speed. The direction defines the axis of clockwise rotation. Units are degrees per second. The default value is [0 0 0].

Version History

Introduced in R2018b