NCTF Control for Friction Compensation of Underactuated Fingers

An appropriate control scheme must be used to alleviate nonlinearities and uncertainties for the plant system. However, this is not a trivial task due to the fact that modeling the nonlinearities such as friction and stiction are always inaccurate. For this, adaptive and robust control approaches are preferable. Thus, this paper investigates a new suggested controller scheme namely Nominal Charactersitic Trajectory Following Contoller (NCTF) to mitigate the nonlinearities and/or uncertaintites in particular to counteract the friction of the servo mechanism for the Bristol Elumotion Robot Hand (BERUL). The NCTF control performance will be compared with an adaptive control in simulation. Comparative performance characteristics have shown that the NCTF control has produced lower total control energy than the adaptive control when controlling the tracking and positioning for underactuated fingers. Keywords—NCTF control, adaptive control and underactuated fingers.