getBody
Get robot body handle by name
Description
Examples
Modify a Robot Rigid Body Tree Model
Make changes to an existing rigidBodyTree
object. You can get replace joints, bodies and subtrees in the rigid body tree.
Load example robots as rigidBodyTree
objects.
load exampleRobots.mat
View the details of the Puma robot using showdetails
.
showdetails(puma1)
-------------------- Robot: (6 bodies) Idx Body Name Joint Name Joint Type Parent Name(Idx) Children Name(s) --- --------- ---------- ---------- ---------------- ---------------- 1 L1 jnt1 revolute base(0) L2(2) 2 L2 jnt2 revolute L1(1) L3(3) 3 L3 jnt3 revolute L2(2) L4(4) 4 L4 jnt4 revolute L3(3) L5(5) 5 L5 jnt5 revolute L4(4) L6(6) 6 L6 jnt6 revolute L5(5) --------------------
Get a specific body to inspect the properties. The only child of the L3
body is the L4
body. You can copy a specific body as well.
body3 = getBody(puma1,'L3');
childBody = body3.Children{1}
childBody = rigidBody with properties: Name: 'L4' Joint: [1x1 rigidBodyJoint] Mass: 1 CenterOfMass: [0 0 0] Inertia: [1 1 1 0 0 0] Parent: [1x1 rigidBody] Children: {[1x1 rigidBody]} Visuals: {} Collisions: {}
body3Copy = copy(body3);
Replace the joint on the L3
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(puma1,'L3',newJoint); showdetails(puma1)
-------------------- Robot: (6 bodies) Idx Body Name Joint Name Joint Type Parent Name(Idx) Children Name(s) --- --------- ---------- ---------- ---------------- ---------------- 1 L1 jnt1 revolute base(0) L2(2) 2 L2 jnt2 revolute L1(1) L3(3) 3 L3 prismatic fixed L2(2) L4(4) 4 L4 jnt4 revolute L3(3) L5(5) 5 L5 jnt5 revolute L4(4) L6(6) 6 L6 jnt6 revolute L5(5) --------------------
Remove an entire body and get the resulting subtree using removeBody
. The removed body is included in the subtree.
subtree = removeBody(puma1,'L4')
subtree = rigidBodyTree with properties: NumBodies: 3 Bodies: {[1x1 rigidBody] [1x1 rigidBody] [1x1 rigidBody]} Base: [1x1 rigidBody] BodyNames: {'L4' 'L5' 'L6'} BaseName: 'L3' Gravity: [0 0 0] DataFormat: 'struct'
Remove the modified L3
body. Add the original copied L3
body to the L2
body, followed by the returned subtree. The robot model remains the same. See a detailed comparison through showdetails
.
removeBody(puma1,'L3'); addBody(puma1,body3Copy,'L2') addSubtree(puma1,'L3',subtree) showdetails(puma1)
-------------------- Robot: (6 bodies) Idx Body Name Joint Name Joint Type Parent Name(Idx) Children Name(s) --- --------- ---------- ---------- ---------------- ---------------- 1 L1 jnt1 revolute base(0) L2(2) 2 L2 jnt2 revolute L1(1) L3(3) 3 L3 jnt3 revolute L2(2) L4(4) 4 L4 jnt4 revolute L3(3) L5(5) 5 L5 jnt5 revolute L4(4) L6(6) 6 L6 jnt6 revolute L5(5) --------------------
Input Arguments
robot
— Robot model
rigidBodyTree
object
Robot model, specified as a rigidBodyTree
object.
bodyname
— Body name
string scalar | character vector
Body name, specified as a string scalar or character vector. A body with this name must be on
the robot model specified by robot
.
Data Types: char
| string
Output Arguments
body
— Rigid body
rigidBody
object
Rigid body, returned as a rigidBody
object. The
returned rigidBodyTree
object is
still a part of the rigidBodyTree
robot model. Use
replaceBody
with a new body
to modify the body in the robot model.
Extended Capabilities
C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.
Usage notes and limitations:
When creating the rigidBodyTree
object, use the syntax that specifies the
MaxNumBodies
as an upper bound for adding bodies to the robot model.
You must also specify the DataFormat
property as a name-value pair. For
example:
robot = rigidBodyTree("MaxNumBodies",15,"DataFormat","row")
To minimize data usage, limit the upper bound to a number close to the expected number of bodies in the model. All data formats are supported for code generation. To use the dynamics functions, the data format must be set to "row"
or "column"
.
The show
and showdetails
functions do not support code generation.
Version History
Introduced in R2016b
See Also
Open Example
You have a modified version of this example. Do you want to open this example with your edits?
MATLAB Command
You clicked a link that corresponds to this MATLAB command:
Run the command by entering it in the MATLAB Command Window. Web browsers do not support MATLAB commands.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)