Crate k [−] [src]
Kinematics(forward/inverse) library using nalgebra.
k
has below functionalities
- Forward kinematics
- Inverse kinematics
- URDF Loader
Forward Kinematics
If you deal robot arm without any branches, you can use VecKinematicChain
,
which is just a Vec of Link
. If you need to deal more complexed
link structure, you have two choices now.
k
has two representation for kinematic chain.
LinkTree
LinkStar
LinkTree
LinkTree
uses Rc<RefCell<Node<T>>>
to handle tree structure.
It can deal complete tree sctuctures, but has lost the safety of rust,
and it has runtime costs.
LinkStar
LinkStar
has very simple structure, Vec of Vec of Link.
This is thread safe and fast, but it is not a tree, it has star structure.
It means that it can deal humanoid with four limbs without fingers,
but it cannot have branches in the limbs like fingers. Only root has branches.
Examples
Build VecKinematicChain
using LinkBuilder
at first.
Instead of using the builder, You can use URDF
format
by urdf
module if you want.
extern crate k; extern crate nalgebra; use k::{VecKinematicChain, LinkBuilder, JointType, JointContainer,KinematicChain, JacobianIKSolverBuilder, InverseKinematicsSolver}; use nalgebra::{Vector3, Translation3}; fn main() { let l0 = LinkBuilder::new() .name("shoulder_link1") .joint("shoulder_pitch", JointType::Rotational { axis: Vector3::y_axis() }, None) .finalize(); let l1 = LinkBuilder::new() .name("shoulder_link2") .joint("shoulder_roll", JointType::Rotational { axis: Vector3::x_axis() }, None) .translation(Translation3::new(0.0, 0.1, 0.0)) .finalize(); let l2 = LinkBuilder::new() .name("shoulder_link3") .joint("shoulder_yaw", JointType::Rotational { axis: Vector3::z_axis() }, None) .translation(Translation3::new(0.0, 0.0, -0.30)) .finalize(); let l3 = LinkBuilder::new() .name("elbow_link1") .joint("elbow_pitch", JointType::Rotational { axis: Vector3::y_axis() }, None) .translation(Translation3::new(0.0, 0.0, -0.15)) .finalize(); let l4 = LinkBuilder::new() .name("wrist_link1") .joint("wrist_yaw", JointType::Rotational { axis: Vector3::z_axis() }, None) .translation(Translation3::new(0.0, 0.0, -0.15)) .finalize(); let l5 = LinkBuilder::new() .name("wrist_link2") .joint("wrist_pitch", JointType::Rotational { axis: Vector3::y_axis() }, None) .translation(Translation3::new(0.0, 0.0, -0.15)) .finalize(); let l6 = LinkBuilder::new() .name("wrist_link3") .joint("wrist_roll", JointType::Rotational { axis: Vector3::x_axis() }, None) .translation(Translation3::new(0.0, 0.0, -0.10)) .finalize(); let mut arm = VecKinematicChain::new("arm", vec![l0, l1, l2, l3, l4, l5, l6]); // set joint angles let angles = vec![0.8, 0.2, 0.0, -1.5, 0.0, -0.3, 0.0]; arm.set_joint_angles(&angles).unwrap(); // get the transform of the end of the manipulator (forward kinematics) let mut target = arm.calc_end_transform(); target.translation.vector[2] += 0.1; let solver = JacobianIKSolverBuilder::new().finalize(); // solve and move the manipulator angles solver.solve(&mut arm, &target) .unwrap_or_else(|err| { println!("Err: {}", err); 0.0f32 }); println!("angles={:?}", arm.get_joint_angles()); }
or you can use urdf module to load URDF file.
let _ = k::urdf::create_tree_from_file::<f32, _>("urdf/sample.urdf").unwrap();
Modules
math | |
urdf |
Structs
JacobianIKSolver |
Inverse Kinematics Solver using Jacobian matrix |
JacobianIKSolverBuilder |
Build |
Joint |
Joint with type |
Link |
Joint and Link |
LinkBuilder |
Build a |
LinkStar |
Robot representation with set of |
LinkTree |
Kinematic Tree using |
NodeIter | |
NodeIterMut | |
Range |
min/max range to check the joint position |
RefKinematicChain |
Kinematic chain using |
VecKinematicChain |
Set of Joint and Link |
Enums
IKError |
The reason of the fail of inverse kinematics |
JointError |
The reason of joint error: |
JointType |
Type of Joint, |
Traits
InverseKinematicsSolver | |
JointContainer | |
KinematicChain | |
LinkContainer |
Functions
create_kinematic_chains |
Create |
create_kinematic_chains_with_dof_limit |
Create |
Type Definitions
LinkNode | |
RcLinkNode |