A greedy assist-as-needed controller for end-effect upper limb rehabilitation robot based on 3-DOF potential field constraints. - Yue Lu; Zixuan Lin; Yahui Li; Jinwang Lv; Jiaji Zhang; Cong Xiao; Ye Liang; Xujiao Chen; Tao Song; Guohong Chai; Guokun Zuo (Frontiers Robotics AI, 2024)