gusucode.com > Mobile Robotics Simulation Toolbox > examples/matlab/kinematics/mrsTripleOmniDiscrete.m
%% EXAMPLE: Triple Omniwheel discrete simulation % Copyright 2018 The MathWorks, Inc. %% Define vehicle wheelRadius = 0.1; % Wheel radius [m] robotRadius = 0.25; % Robot radius [m] wheelAngles = [0, 2*pi/3, -2*pi/3]; % Wheel angles [rad] vehicle = TripleOmniwheel(wheelRadius,robotRadius,wheelAngles); %% Simulation parameters sampleTime = 0.01; % Sample time [s] initPose = [0; 0; pi/4]; % Initial pose (x y theta) bodyMode = true; % True for body frame speeds, false for world frame speeds % Initialize time, input, and pose arrays tVec = 0:sampleTime:10; % Time array vxRef = 0.2*ones(size(tVec)); % Reference x speed vyRef = 0.1*ones(size(tVec)); % Reference y speed wRef = zeros(size(tVec)); % Reference angular speed wRef(tVec < 5) = -0.5; wRef(tVec >=5) = 0.5; ref = [vxRef;vyRef;wRef]; pose = zeros(3,numel(tVec)); % Pose matrix pose(:,1) = initPose; %% Simulation loop for idx = 2:numel(tVec) % Solve inverse kinematics to find wheel speeds if bodyMode wheelSpeeds = inverseKinematics(vehicle,ref(:,idx-1)); else refWorld = worldToBody(ref(:,idx-1),pose(:,idx-1)); wheelSpeeds = inverseKinematics(vehicle,refWorld); end % Compute the velocities velB = forwardKinematics(vehicle,wheelSpeeds); vel = bodyToWorld(velB,pose(:,idx-1)); % Perform forward discrete integration step pose(:,idx) = pose(:,idx-1) + vel*sampleTime; end %% Display results close all figure hold on plot(pose(1,1),pose(2,1),'ro', ... pose(1,end),pose(2,end),'go', ... pose(1,:),pose(2,:),'b-'); axis equal title('Vehicle Trajectory'); xlabel('X [m]') ylabel('Y [m]') legend('Start','End','Trajectory')