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platform

Add platform to radar scenario

Description

example

plat = platform(scenario) creates a new Platform object, plat, and adds the platform to the radar scenario, scenario.

example

plat = platform(scenario,Name,Value) creates a new Platform object with additional properties specified by one or more name-value arguments.

Examples

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Create a radar scenario.

rs = radarScenario;

Create a platform with default property values and add it to the scenario.

plat = platform(rs);

Specify the trajectory of the platform as a circular path of radius 10 m for one second. This is accomplished by placing waypoints in a circular shape, ensuring that the first and last waypoint are the same.

wpts = [0 10 0; 10 0 0; 0 -10 0; -10 0 0; 0 10 0];
times = [0; 0.25; .5; .75; 1.0];
plat.Trajectory = waypointTrajectory(wpts,times);

Display the properties of the platform object.

plat
plat = 
  Platform with properties:

       PlatformID: 1
          ClassID: 0
         Position: [0 10 0]
      Orientation: [-1.7180e-05 0 0]
       Dimensions: [1x1 struct]
       Trajectory: [1x1 waypointTrajectory]
    PoseEstimator: [1x1 insSensor]
         Emitters: {}
          Sensors: {}
       Signatures: {[1x1 rcsSignature]}

Perform the simulation, advancing one time step at a time. Display the simulation time and the position and velocity of the platform at each time step.

while advance(rs)  
    p = pose(plat);
    disp(strcat("Time = ",num2str(rs.SimulationTime)))
    disp(strcat("  Position = [",num2str(p.Position),"]"))
    disp(strcat("  Velocity = [",num2str(p.Velocity),"]"))
end
Time = 0
  Position = [0  10   0]
  Velocity = [62.8318 -1.88403e-05            0]
Time = 0.1
  Position = [5.8779      8.0902           0]
  Velocity = [50.832     -36.9316            0]
Time = 0.2
  Position = [9.5106      3.0902           0]
  Velocity = [19.4161     -59.7566            0]
Time = 0.3
  Position = [9.5106     -3.0902           0]
  Velocity = [-19.4161     -59.7567            0]
Time = 0.4
  Position = [5.8779     -8.0902           0]
  Velocity = [-50.832     -36.9316            0]
Time = 0.5
  Position = [0 -10   0]
  Velocity = [-62.8319  1.88181e-05            0]
Time = 0.6
  Position = [-5.8779     -8.0902           0]
  Velocity = [-50.832      36.9316            0]
Time = 0.7
  Position = [-9.5106     -3.0902           0]
  Velocity = [-19.4161      59.7566            0]
Time = 0.8
  Position = [-9.5106      3.0902           0]
  Velocity = [19.4161      59.7566            0]
Time = 0.9
  Position = [-5.8779      8.0902           0]
  Velocity = [50.832      36.9316            0]
Time = 1
  Position = [-7.10543e-15           10            0]
  Velocity = [62.8319 -1.88404e-05            0]

Create a radar scenario.

rs = radarScenario;

Create a cuboid platform for a truck with dimensions 5 m by 2.5 m by 3.5 m.

dim1 = struct('Length',5,'Width',2.5,'Height',3.5,'OriginOffset',[0 0 0]);
truck = platform(rs,'Dimension',dim1);

Specify the trajectory of the truck as a circle with radius 20 m.

truck.Trajectory = waypointTrajectory('Waypoints', ...
    [20*cos(2*pi*(0:10)'/10) 20*sin(2*pi*(0:10)'/10) -1.75*ones(11,1)], ...
    'TimeOfArrival',linspace(0,50,11)');

Create the platform for a small quadcopter with dimensions 0.3 m by 0.3 m by 0.1 m.

dim2 = struct('Length',.3,'Width',.3,'Height',.1,'OriginOffset',[0 0 0]);
quad = platform(rs,'Dimension',dim2);

Specify the trajectory of the quadcopter as a circle 10 m above the truck with a small angular delay. Note that the negative z coordinates correspond to positive elevation.

quad.Trajectory = waypointTrajectory('Waypoints', ...
    [20*cos(2*pi*((0:10)'-.6)/10) 20*sin(2*pi*((0:10)'-.6)/10) -11.80*ones(11,1)], ...
    'TimeOfArrival',linspace(0,50,11)');

Visualize the results using theaterPlot.

tp = theaterPlot('XLim',[-30 30],'YLim',[-30 30],'Zlim',[-12 5]);
pp1 = platformPlotter(tp,'DisplayName','truck','Marker','s');
pp2 = platformPlotter(tp,'DisplayName','quadcopter','Marker','o');

Specify a view direction and run the simulation.

view(-28,37);
set(gca,'Zdir','reverse');

while advance(rs)
    poses = platformPoses(rs);
    plotPlatform(pp1,poses(1).Position,truck.Dimensions,poses(1).Orientation);
    plotPlatform(pp2,poses(2).Position,quad.Dimensions,poses(2).Orientation);
end

Figure contains an axes object. The axes object contains 2 objects of type line. These objects represent truck, quadcopter.

Input Arguments

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Radar scenario, specified as a radarScenario object.

Name-Value Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: 'ClassID',2

Platform classification identifier, specified as a nonnegative integer. You can define your own platform classification scheme and assign ClassID values to platforms according to the scheme. The value of 0 is reserved for an object of unknown or unassigned class.

Example: 5

Data Types: double

Platform motion, specified as a kinematicTrajectory object, a waypointTrajectory object, or a geoTrajectory object. The trajectory object defines the time evolution of the position and velocity of the platform frame origin, as well as the orientation of the platform frame relative to the scenario frame.

  • When the IsEarthCentered property of the scenario is set to false, use the kinematicTrajectory or the waypointTrajectory object. By default, the platform uses a stationary kinematicTrajectory object.

  • When the IsEarthCentered property of the scenario is set to true, use the geoTrajectory object. By default, the platform uses a stationary geoTrajectory object.

This property is read-only.

Current position of the platform, specified as a three-element vector of scalars.

  • When the IsEarthCentered property of the scenario is set to false, the position is specified as a three-element Cartesian state [x, y, z] in meters.

  • When the IsEarthCentered property of the scenario is set to true, the position is specified as a three-element geodetic state: latitude in degrees, longitude in degrees, and altitude in meters.

Specify this argument only when creating a stationary platform. If you choose to specify the trajectory of the platform, use the Trajectory argument.

Data Types: double

This property is read-only.

Orientation of the platform, specified as a three-element numeric vector in degrees. The three elements are the [yaw, pitch, roll] rotation angles from the local reference frame to the body frame of the platform.

Specify this argument only when creating a stationary platform. If you choose to specify the orientation over time, use the Trajectory argument.

Data Types: double

Platform signatures, specified as a cell array of signature objects or an empty cell array ({}). The default value is a cell array containing an rcsSignature object with default property values. If you have Sensor Fusion and Tracking Toolbox™, then the cell array can also include irSignature (Sensor Fusion and Tracking Toolbox) and tsSignature (Sensor Fusion and Tracking Toolbox) objects. The cell array contains at most one instance for each type of signature object. A signature represents the reflection or emission pattern of a platform such as its radar cross-section, target strength, or IR intensity.

Platform dimensions and origin offset, specified as a structure. The structure contains the Length, Width, Height, and OriginOffset of a cuboid that approximates the dimensions of the platform. The OriginOffset is the position vector from the center of the cuboid to the origin of the platform coordinate frame. The OriginOffset is expressed in the platform coordinate system. For example, if the platform origin is at the center of the cuboid rear face as shown in the figure, then set OriginOffset as [-L/2, 0, 0]. The default value for Dimensions is a structure with all fields set to zero, which corresponds to a point model.

Platform depicted as a cuboid whose center is offset from the center of the platform frame coordinate system

Fields of Dimensions

FieldsDescriptionDefault
LengthDimension of a cuboid along the x direction0
WidthDimension of a cuboid along the y direction0
HeightDimension of a cuboid along the z direction0
OriginOffsetPosition of the platform coordinate frame origin with respect to the cuboid center[0 0 0 ]

Example: struct('Length',5,'Width',2.5,'Height',3.5,'OriginOffset',[-2.5 0 0])

Data Types: struct

Platform pose estimator, specified as a pose-estimator object such as an insSensor object. The pose estimator determines platform pose with respect to the local NED scenario coordinates. The interface of any pose estimator must match the interface of the insSensor object. By default, the platform sets the pose estimator accuracy properties to zero.

Emitters mounted on the platform, specified as a cell array of emitter objects such as radarEmitter objects. If you have Sensor Fusion and Tracking Toolbox, then the cell array can also include sonarEmitter (Sensor Fusion and Tracking Toolbox) objects.

Sensors mounted on the platform, specified as a cell array of sensor objects such as radarDataGenerator objects.

Output Arguments

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Scenario platform, returned as a Platform object.

Introduced in R2021a