TRAC-IK

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An open-source numerical inverse-kinematics solver that's more reliable and faster than KDL.

TRAC-IK is an open-source inverse kinematics library — solving for joint angles from a target end-effector pose — released by Patrick Beeson and Barrett Ames of TRACLabs at the 2015 IEEE Humanoids conference. The KDL solver commonly used in ROS iterates with Newton's method, which tends to get stuck and fail near joint limits. TRAC-IK instead runs two methods in parallel: a KDL-style Jacobian iteration with random restarts, and a version that formulates IK as nonlinear optimization solved with SQP (Sequential Quadratic Programming); whichever finishes first is used, giving a clear boost to both success rate and speed. It provides a C++ interface and a MoveIt plugin, and works with any serial robot arm.

ExampleSwitch the solver in MoveIt's kinematics.yaml from KDL to trac_ik_kinematics_plugin, and a 7-axis arm sees fewer IK failures when working near its joint limits.

Also called: trac_ik
Related: Inverse Kinematics (IK) · Numerical Inverse Kinematics · Orocos KDL · IKFast · MoveIt Motion Planning Framework · Joint Limits
Sources: TRAC-IK — TRACLabs
trac_ik — ROS Wiki