An adaptive predefined performance control problem is investigated for a class of multiple-input multiple-output systems with unknown control direction and unknown backlash-like hysteresis nonlinearities by using generalized fuzzy hyperbolic model (GFHM). Compared with the existing methods, the main features are as follows: the prediction error is introduced to construct the adaptive laws, which means that the approximate accuracy of the GFHM is solved; the Nussbaum-type gain is utilized to deal with the unknown control direction, which avoids the requirement of direction  a priori ; and by transforming the tracking errors into new error variables, the prescribed steady-state and transient performance can be ensured. It is shown that the proposed control approach can guarantee that all the signals of the resulting closed-loop systems are bounded, and the output tracks a desired trajectory, while the tracking errors are confined all times within the prescribed bounds. Finally, two simulation results and some comparisons are provided to verify the effectiveness of the proposed approach. Since the proposed control strategy is only implemented in a healthy case, how to extend the strategy to a faulty case will be a further topic.
['Lei Liu', 'Zhanshan Wang', 'Zhanjun Huang', 'Huaguang Zhang']
Adaptive Predefined Performance Control for MIMO Systems With Unknown Direction via Generalized Fuzzy Hyperbolic Model