Rigid body tree D-H parameters
7 views (last 30 days)
Show older comments
Hi I'm using matlab 2016/2017 with robotic toolbox installed. I've followed all the tutorials to learn how to use the RigidBody class. However, when I try to build my own rigid body tree it seems that something is wrong with my frames orientations. I don't know exactly how the DH parameter alpha for my third joint is not taken into account I've attached a picture of my kinematic diagram and a sample of my code. If somebody can help.
Thanks
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/191318/image.png)
if true
d67 = 0 ; %317.56 ;
alpha67 = 62*pi/180 ;
r67 = 0 ;
d78 = 0 ; % -53.03 ;
alpha78 = 17*pi/180 ;
r78 = 0 ; %172.23 ;
d89 = 0 ; %343.18 ;
r89 = 0 ; %38.74 ;
r910 = 0 ; % 211.5 ;
r1011 = 0 ; %334.95 ;
theta1112 = 65.98*pi/180 ;
r1112 = 0 ; % 10
dEe = 0 ; %100 ;
% DH = [ r_n alpha_n d_n theta_n]
DHparams = [0 alpha67 0 0;
r78 alpha78 d78 0;
r89 -pi/2 d89 0;
r910 0 0 0;
r1011 0 0 0;
r1112 -pi/2 0 theta1112;
0 0 dEe 0];
body1 = robotics.RigidBody('body1') ; % create the first body
jnt1 = robotics.Joint('jnt1','revolute'); % initial joint fixed to base
setFixedTransform(jnt1,DHparams(1,:),'dh') ; %
body1.Joint = jnt1;
Rcm = robotics.RigidBodyTree;
addBody(Rcm,body1,'base') ;
body2 = robotics.RigidBody('body2');
body3 = robotics.RigidBody('body3');
body4 = robotics.RigidBody('body4');
body5 = robotics.RigidBody('body5');
body6 = robotics.RigidBody('body6');
Endeff = robotics.RigidBody('endeffector');
jnt2 = robotics.Joint('jnt2','revolute');
jnt3 = robotics.Joint('jnt3','revolute');
jnt4 = robotics.Joint('jnt4','revolute');
jnt5 = robotics.Joint('jnt5','revolute');
jnt6 = robotics.Joint('jnt6','prismatic');
jnt3.JointAxis(3) ;
setFixedTransform(jnt2,DHparams(2,:),'dh');
setFixedTransform(jnt3,DHparams(3,:),'dh');
setFixedTransform(jnt4,DHparams(4,:),'dh');
setFixedTransform(jnt5,DHparams(5,:),'dh');
setFixedTransform(jnt6,DHparams(6,:),'dh');
setFixedTransform(Endeff.Joint,DHparams(7,:),'dh');
body2.Joint = jnt2;
body3.Joint = jnt3;
body4.Joint = jnt4;
body5.Joint = jnt5;
body6.Joint = jnt6;
addBody(Rcm,body2,'body1')
addBody(Rcm,body3,'body2')
addBody(Rcm,body4,'body3')
addBody(Rcm,body5,'body4')
addBody(Rcm,body6,'body5')
addBody(Rcm,Endeff,'body6')
show(Rcm);
axis on
view([90.000 0.000])
end
0 Comments
Accepted Answer
More Answers (0)
See Also
Categories
Find more on Assembly in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!