Is it possible to call a rigidBodyTree robot model in a Matlab function in Simulink?

Question

Lorenzo Scalera 2020-5-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/526534-is-it-possible-to-call-a-rigidbodytree-robot-model-in-a-matlab-function-in-simulink

评论： Lorenzo Scalera 2021-4-9

采纳的回答： Yiping Liu

Hi everybody,

I am trying to use the Robotic System Toolbox functions inside a Matlab function in Simulink.

I am having troubles in importing the rigidBodyTree model in the Matlab function.

How can I manage this issue?

Thank you very much in advance!

4 个评论
显示 2更早的评论隐藏 2更早的评论

Valeria Leto 2021-4-7

Hi Lorenzo! could you post your code? I have the same problem but I didn't understand how to fix it.

Lorenzo Scalera 2021-4-9

在 MATLAB Online 中打开

Ciao Valeria, I have created the robot RigidBodyTree in a way similar to what Yiping did.

I have defined a persistent variable, which is initialized only once when the code is run at the first time. Then, "robot" is automatically kept in memory during code execution.

"createRigidBodyTree" is a custom function in which I have built the manipulator RigidBodyTree starting from the DH parameters, as explained in this link:

https://it.mathworks.com/help/robotics/ref/rigidbodytree.html

I hope it can help!

persistent robot
if isempty(robot)
    robot=createRigidBodyTree;
end

function robot = createRigidBodyTree
dhparams = [...
    
robot = rigidBodyTree("MaxNumBodies",8,"DataFormat","row");
body1 = rigidBody('body1');
jnt1 = rigidBodyJoint('jnt1','revolute');
... (please see the link)
    
end

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Yiping Liu 2020-11-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/526534-is-it-possible-to-call-a-rigidbodytree-robot-model-in-a-matlab-function-in-simulink#answer_534230

编辑：Yiping Liu 2021-4-7

在 MATLAB Online 中打开

Lorenzo, the persistent variable is the correct way.

You should also check out the rigid body tree algorithm Simulink blocks in RST:

Manipulator Algorithm Design — Blocks

An example of using the persistent variable (NOTE to get a robot inside a function, starting in 21a, you can also use loadrobot command or the new API on rigidBodyTree class called writeAsFunction, both supporting codegen)

function [q, solInfo] = computeIK(T, qini, solTol, gradTol)
%COMPUTEIK
%  input:
%  Q - 4x4 homogenerous matrix representing end-effector pose
%  qini - initial guess for joint configurations (a vector)
%  solTol - Solution Toleraance
%  gradTol - Gradient Tolerance
persistent ik
if isempty(ik)
    robot = robotics.manip.internal.robotplant.puma560DH(); % Since 21a, there are better/cleaner ways to create a robot inside a function.
    robot.DataFormat = 'column';
    ik = inverseKinematics('RigidBodyTree', robot);
    ik.SolverParameters.MaxIterations = 100; 
    ik.SolverParameters.AllowRandomRestart = false;
end
ik.SolverParameters.SolutionTolerance = solTol;
ik.SolverParameters.GradientTolerance = gradTol;
[q, solInfo] = ik('L6', T, ones(1,6), qini);
end
% codegen command:
% codegen computeIK.m -args {eye(4), ones(1,13), 0, 0}