/HIRO_Panda_TRAC_IK

Inverse Kinematics Engine for HIRO's Franka Emika Panda for Cartesian Pose Control.

Primary LanguageJupyter NotebookGNU Lesser General Public License v2.1LGPL-2.1

Franka Panda TracIK Inverse Kinematics Solver

The Franka Panda Inverse Kinematics Solver Package is a ROS package developed in the HIRO Lab at CU Boulder. It is developed for Cartesian Pose control.

Running this code publishes to a topic with a geometry_msgs/Pose message.

Details

Trac_IK, an IK solver with a solve rate of 99.88% for the Franka Emika Panda, is used to compute the 7 resulting joint angles for the arm. From there, the user can specify the trajectory method in which the robot moves from one position to another.

Additionally, there is an accompanying Jupyter Notebook (here) for Catmull-Rom Splines, which is the best (smoothest) trajectory method for the Panda in this repo.

Note: This package has been soley tested for the real robot, and doesn't work for the Franka Panda simulation. However, a posible future extension of this work would be for simulation!

Installation, Building, and Usage

Requires

  • trac_ik: The inverse kinematics package compatible with Franka Panda (and a variety of other robot arms)

Steps

# create a new catkin workspace...

mkdir -p catkin_ws/src
cd catkin_ws/src
git clone https://bitbucket.org/traclabs/trac_ik.git
git clone https://github.com/HIRO-group/HIRO_Panda_TRAC_IK

cd ..

catkin build

source devel/setup.bash

User Information

  1. In order to run through the Inverse Kinematics, once the build command succeeds, to see IK in action:

source devel/setup.bash
roslaunch hiro_panda_ik hiro_panda_ik_controller.launch robot_ip:=<robot-url> trajectory_method:=<1,2,3 or 4>

  1. Note: The trajectory method is the method which is used to move the arm after the inverse kinematics are calculated. The options are:

    • 1: Constant velocity to each point (default option when trajectory_method is not provided)
    • 2: Increase velocity at a constant rate, then maintain max rate, then decrease at constant rate once near end of trajectory ('trapezoid' method)
    • 3: Catmull-Rom splines where velocity is calculated as a function of position (smoothest and best method)

  2. To publish to the topic:

rostopic pub -1 /hiro_panda/goto_pose geometry_msgs/Pose "{position:{ x: 0.4, y: 0.4, z: 0.5}, orientation:{ x: 0.0, y: 0.0, z: 0.0, w: 1.0}}"
  1. The above example will not changed the orientation of the arm; it will move it to the desired 3-d coordinates. Make sure that the orientation (quarternion) normalizes to 1.