A new inverse kinematics algorithm with path tracking capability under velocity and acceleration constraints

Kinematic control of robotic manipulators is based on an inverse kinematic transformation which feeds the reference values corresponding to the assigned end-effector trajectory to the joint servos. However, the occurrence of saturation in the joint actuating system is responsible for tracking errors affecting both the followed path and the time law to describe it. In this paper, a new second-order inverse kinematics algorithm is developed which takes into account the joint velocity and acceleration limits while ensuring tracking of the assigned end-effector path. This goal is achieved by properly modifying the time law with a time warp when joint limits are encountered. The proposed technique is designed for online operation and requires a light computational burden. Case studies are developed to analyze the performance of the proposed method.