replaceJoint
Replace joint on body
Description
Examples
Make changes to an existing rigidBodyTree object. You can get replace joints, bodies and subtrees in the rigid body tree.
Load an ABB IRB-120T manipulator from the Robotics System Toolbox™ loadrobot. It is specified as a rigidBodyTree object.
manipulator = loadrobot("abbIrb120T");View the robot with show and read the details of the robot using showdetails.
show(manipulator);
showdetails(manipulator)
-------------------- Robot: (8 bodies) Idx Body Name Joint Name Joint Type Parent Name(Idx) Children Name(s) --- --------- ---------- ---------- ---------------- ---------------- 1 base base_link-base fixed base_link(0) 2 link_1 joint_1 revolute base_link(0) link_2(3) 3 link_2 joint_2 revolute link_1(2) link_3(4) 4 link_3 joint_3 revolute link_2(3) link_4(5) 5 link_4 joint_4 revolute link_3(4) link_5(6) 6 link_5 joint_5 revolute link_4(5) link_6(7) 7 link_6 joint_6 revolute link_5(6) tool0(8) 8 tool0 joint6-tool0 fixed link_6(7) --------------------
Get a specific body to inspect the properties. The only child of the link_3 body is the link_4 body. You can copy a specific body as well.
body3 = getBody(manipulator,"link_3");
childBody = body3.Children{1}childBody =
rigidBody with properties:
Name: 'link_4'
Joint: [1×1 rigidBodyJoint]
Mass: 1.3280
CenterOfMass: [0.2247 1.5000e-04 4.1000e-04]
Inertia: [0.0028 0.0711 0.0723 1.3052e-05 -1.3878e-04 -6.6037e-05]
Parent: [1×1 rigidBody]
Children: {[1×1 rigidBody]}
Visuals: {'Mesh Filename link_4.stl'}
Collisions: {'Mesh Filename link_4.stl'}
FrameNames: {'link_4'}
ParentFrame: 'link_3'
body3Copy = copy(body3);
Replace the joint on the link_3 body. You must create a new Joint object and use replaceJoint to ensure the downstream body geometry is unaffected. Call setFixedTransform if necessary to define a transform between the bodies instead of with the default identity matrices.
newJoint = rigidBodyJoint("prismatic"); replaceJoint(manipulator,"link_3",newJoint); showdetails(manipulator)
-------------------- Robot: (8 bodies) Idx Body Name Joint Name Joint Type Parent Name(Idx) Children Name(s) --- --------- ---------- ---------- ---------------- ---------------- 1 base base_link-base fixed base_link(0) 2 link_1 joint_1 revolute base_link(0) link_2(3) 3 link_2 joint_2 revolute link_1(2) link_3(4) 4 link_3 prismatic fixed link_2(3) link_4(5) 5 link_4 joint_4 revolute link_3(4) link_5(6) 6 link_5 joint_5 revolute link_4(5) link_6(7) 7 link_6 joint_6 revolute link_5(6) tool0(8) 8 tool0 joint6-tool0 fixed link_6(7) --------------------
Remove an entire body and get the resulting subtree using removeBody. The removed body is included in the subtree.
subtree = removeBody(manipulator,"link_4")subtree =
rigidBodyTree with properties:
NumBodies: 4
Bodies: {[1×1 rigidBody] [1×1 rigidBody] [1×1 rigidBody] [1×1 rigidBody]}
Base: [1×1 rigidBody]
BodyNames: {'link_4' 'link_5' 'link_6' 'tool0'}
BaseName: 'link_3'
Gravity: [0 0 0]
DataFormat: 'struct'
FrameNames: {'link_3' 'link_4' 'link_5' 'link_6' 'tool0'}
show(subtree);
Remove the modified link_3 body. Add the original copied link_3 body to the link_2 body, followed by the returned subtree. The robot model remains the same. See a detailed comparison through showdetails.
removeBody(manipulator,"link_3"); addBody(manipulator,body3Copy,"link_2") addSubtree(manipulator,"link_3",subtree) showdetails(manipulator)
-------------------- Robot: (8 bodies) Idx Body Name Joint Name Joint Type Parent Name(Idx) Children Name(s) --- --------- ---------- ---------- ---------------- ---------------- 1 base base_link-base fixed base_link(0) 2 link_1 joint_1 revolute base_link(0) link_2(3) 3 link_2 joint_2 revolute link_1(2) link_3(4) 4 link_3 joint_3 revolute link_2(3) link_4(5) 5 link_4 joint_4 revolute link_3(4) link_5(6) 6 link_5 joint_5 revolute link_4(5) link_6(7) 7 link_6 joint_6 revolute link_5(6) tool0(8) 8 tool0 joint6-tool0 fixed link_6(7) --------------------
Input Arguments
Extended Capabilities
Version History
Introduced in R2016b
