When it is difficult to structure an accurate dynamic model,
a fuzzy control could be taken into consideration, in order to
represent and implement an intuitive knowledge about how to
handle a physical system [63]. A fuzzy controller consists of four
main blocks: the fuzzification block, which interprets the inputs;
the fuzzy-rules block, which holds the knowledge of how to control
the system; an interface mechanism to select which rule should
be implemented; and the defuzzification block which converts
the fuzzy results into desired output signals. Fuzzy controller,
however, requires many variables to be tuned manually according
to the specific motion tasks and individuals [64]. In this study