Prioritized Inverse Kinematics ROS library pik_ros.

The PIK solver gives a solution to the prioritized positional inverse kinematics problem: selecting joint positions that result in optimizing a number of prioritized tasks for different links in the kinematic chain.

In the image bellow you can see an example with following priorities:

spraying_frame position, shown with a blue sphere
spraying_frame approach axis orientation, shown with a blue arrow
forearm_link position, shown with a purple sphere

PIK ROS solver uses sequential prioritized optimization, where PtscEigen is used for prioritized optimization, and MoveIt is used for the robot model data and Jacobian calculation.

🖥️ Using the library

⚙️ Dependencies

This project depends on ROS, MoveIt and PtscEigen.

⚙️ Build

Clone to your catkin workspace and build with

catkin build pik_ros

Usage example

//Include the library header 
#include <PikRos.hpp>
//Construct the Pik object 
PikRos::Pik my_pik( nh,                           //ros node handle
                    "my_robot_name",              //namespace for robot description
                    "my_joint_model_group_name",  //for MoveIt
                    settings);                    //PikRos::Settings object
//Define a vector of tasks, with descending priorities 
//IkTask constructor takes arguments: (task_type, frame, desired_value)
std::vector<PikRos::IkTask> ik_tasks{ 
  PikRos::IkTask( PikRos::FRAME_POSITION, "spraying_frame", desired_tool_position ), 
  PikRos::IkTask( PikRos::FRAME_APPROACH_AXIS, "spraying_frame", desired_approach_vector ),
  PikRos::IkTask( PikRos::FRAME_POSITION, "forearm_link", desired_elbow_position ) 
};
// Solve problem
Eigen::VectorXd q = my_pik.solve( ik_tasks, q_initial_guess );

Including the library in your ROS project

Find the pik_ros pacakage in your CMakeLists.txt file:

find_package( catkin REQUIRED COMPONENTS 
              pik_ros 
              ... )

And link the catkin libraries:

target_link_libraries(test_kinova_ik 
                      ${catkin_LIBRARIES}
                      ... )

For complete examples of usage of the library see kinova_gen3_pik_examples

Available Tasks

Priorities are given to the solver as a vector of PikRos::IkTask objects, with descending priorities.

PikRos::IkTaskType describes a particular task type given to the solver. Available task types are:

FRAME_POSITION - Frame position task, has a value of [x, y, z]^T in meters
FRAME_ORIENTATION - Frame orientation task, has a quaternion value [w, x, y, z]^T
FRAME_POSE - Frame pose task, a combination of FRAME_POSITION and FRAME_ORIENTATION tasks
FRAME_APPROACH_AXIS - Frame approach axis task, has a value of a 3D vector [x, y, z]^T

Citing

TODO

📝 License

Materials in this repository are distributed under the following license:

All software is licensed under the BSD 3-Clause License.