An Observer-Based Responsive Variable Impedance Control for Dual-User Haptic Training System. - A. Rashvand; R. Heidari; Mohammad Motaharifar; Ali Hassani 004; M. R. Dindarloo; M. J. Ahmadi; Keyvan Hashtrudi-Zaad; Mahdi Tavakoli; Hamid D. Taghirad (IROS, 2022)