Online Iterative Learning with Forward Simulation for Sub-minimum End-effector Displacement Positioning

Abstract

Precision is a crucial performance indicator for robot arms. During interacting with human, high precision enables a robot arm to be used effectively and safely, while low precision may lead to safety issues. Traditional methods for improving robot arm precision rely on error compensation. However, these methods are often not robust and lack adaptability. Learning-based methods offer greater flexibility and adaptability, while current researches show that they often fall short in achieving high precision and struggle to handle many scenarios requiring high precision. In this paper, we propose a novel high-precision robot arm manipulation framework based on online iterative learning and forward simulation, which can achieve positioning error (precision) less than end-effector physical minimum displacement. In other words, our proposed method can compensate for the precision-limitation of the hardware structure of the robot arms. Furthermore, we consider the joint angular resolution of the real robot arm, which is usually neglected in related works. A series of experiments on both simulation and real UR3 robot arm platforms demonstrate that our proposed method is effective and promising. The related code will be available soon.