An algorithm for online inverse kinematics with path tracking capability under velocity and acceleration constraints

Abstract

Typical tasks for robotic manipulators are specified in terms of an end-effector trajectory. On the other hand, the robot arm is actuated at the joints thus requiring control actions to be performed by the joint servos. Inverse kinematics algorithms map the desired task-space trajectory into a suitable joint-space trajectory. In this paper, a new second-order inverse kinematics algorithm is developed which takes into account the joint velocity and acceleration limits while pursuing tracking of the assigned end-effector path. The proposed technique is designed for real-time operation and requires a light computational burden. This goal is achieved by properly modifying the time law with a time warp when joint limits are encountered. Case studies are developed to analyze the performance of the proposed method.