updateMesh

Update robot platform body mesh

Syntax

updateMesh(platform,type,Name=Value)

Description

updateMesh(platform,type,Name=Value) updates the body mesh of the robot platform with the specified mesh type and specifies additional options using one or more name-value pair arguments.

Examples

Create and Simulate Robot Scenario

Create a robot scenario.

scenario = robotScenario(UpdateRate=100,StopTime=1);

Add the ground plane and a box as meshes.

addMesh(scenario,"Plane",Size=[3 3],Color=[0.7 0.7 0.7]);
addMesh(scenario,"Box",Size=[0.5 0.5 0.5],Position=[0 0 0.25], ...
        Color=[0 1 0])

Create a waypoint trajectory for the robot platform using an ENU reference frame.

waypoint = [0 -1 0; 1 0 0; -1 1 0; 0 -1 0];
toa = linspace(0,1,length(waypoint));
traj = waypointTrajectory("Waypoints",waypoint, ...
                          "TimeOfArrival",toa, ...
                          "ReferenceFrame","ENU");

Create a rigidBodyTree object of the TurtleBot 3 Waffle Pi robot with loadrobot.

robotRBT = loadrobot("robotisTurtleBot3WafflePi");

Create a robot platform with trajectory.

platform = robotPlatform("TurtleBot",scenario, ...
                         BaseTrajectory=traj);

Set up platform mesh with the rigidBodyTree object.

updateMesh(platform,"RigidBodyTree",Object=robotRBT)

Create an INS sensor object and attach the sensor to the platform.

ins = robotSensor("INS",platform,insSensor("RollAccuracy",0), ...
                  UpdateRate=scenario.UpdateRate);

Visualize the scenario.

[ax,plotFrames] = show3D(scenario);
axis equal
hold on

In a loop, step through the trajectory to output the position, orientation, velocity, acceleration, and angular velocity.

count = 1;
while ~isDone(traj)
    [Position(count,:),Orientation(count,:),Velocity(count,:), ...
     Acceleration(count,:),AngularVelocity(count,:)] = traj();
    count = count+1;
end

Create a line plot for the trajectory. First create the plot with plot3, then manually modify the data source properties of the plot. This improves the performance of the plotting.

trajPlot = plot3(nan,nan,nan,"Color",[1 1 1],"LineWidth",2);
trajPlot.XDataSource = "Position(:,1)";
trajPlot.YDataSource = "Position(:,2)";
trajPlot.ZDataSource = "Position(:,3)";

Set up the simulation. Then, iterate through the positions and show the scene each time the INS sensor updates. Advance the scene, move the robot platform, and update the sensors.

setup(scenario)
for idx = 1:count-1
    % Read sensor readings.
    [isUpdated,insTimestamp(idx,1),sensorReadings(idx)] = read(ins);
    if isUpdated
        % Use fast update to move platform visualization frames.
        show3D(scenario,FastUpdate=true,Parent=ax);
        % Refresh all plot data and visualize.
        refreshdata
        drawnow limitrate
    end
    % Advance scenario simulation time and move platform.
    advance(scenario);
    motion = [Position(idx,:),Velocity(idx,:),Acceleration(idx,:), ...
              compact(Orientation(idx,:)),AngularVelocity(idx,:)];
    move(platform,"base",motion)
    % Update all sensors in the scene.
    updateSensors(scenario)
end
hold off

Input Arguments

platform — Robot platform in scenario

robotPlatform object

Robot platform in the scenario, specified as a robotPlatform object.

type — Type of mesh

"Cuboid" | "GroundVehicle" | "RigidBodyTree" | "Custom"

Type of mesh, specified as "Cuboid", "GroundVehicle", "RigidBodyTree", or "Custom".

Data Types: char | string

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example:

Position — Relative mesh position in body frame

[0 0 0] (default) | vector of form [x y z]

Relative mesh position in the body frame, specified as a vector of the form [x y z] in meters.

Data Types: single | double

Orientation — Relative mesh orientation in body frame

[1 0 0 0] (default) | vector of form [w x y z] | quaternion object

Relative mesh orientation in the body frame, specified as a quaternion vector of the form [w x y z] or a quaternion object.

Data Types: single | double

Offset — Transformation of mesh relative to body frame

4-by-4 homogeneous transformation matrix

Transformation of mesh relative to the body frame, specified as a 4-by-4 homogeneous transformation matrix. The matrix maps points in the platform mesh frame to points in the body frame.

Data Types: single | double

Color — Robot platform body mesh color

[1 0 0] (default) | RGB triplet

Robot platform body mesh color, specified as a RGB triplet, except for the rigid body mesh.

Data Types: single | double

Faces — Faces of custom robot platform mesh

N-by-3 matrix of positive integers

Faces of the custom robot platform mesh, specified as an N-by-3 matrix of positive integers. The three elements in each row are the indices of the three points in the vertices forming a triangle face. N is the number of faces.

Data Types: single | double

Vertices — Vertices of custom robot platform mesh

N-by-3 matrix of real scalars

Vertices of the custom robot platform mesh, specified as an N-by-3 matrix of real scalars. The first, second, and third element of each row represents the x-, y-, and z-position of each vertex, respectively. N is the number of vertices.

Data Types: single | double

Size — Size of cuboid robot platform mesh

[1 0.5 0.3] (default) | vector of form [xlength ylength zlength]

Size of the cuboid robot platform mesh, specified as a vector of form [xlength ylength zlength] in meters.

Data Types: single | double

Scale — Scale of ground vehicle robot platform mesh

1 (default) | scalar

Scale of the ground vehicle robot platform mesh, specified as a scalar. Scale is unitless.

Data Types: single | double

Object — Rigid body tree robot platform

[] (default) | rigidBodyTree object

Rigid body tree robot platform, specified as a rigidBodyTree object.

Version History

Introduced in R2022a