The combination of FireFly and T2FSMC has succesfully not only in overcoming the
chattering and robustness problems on mobile inverted pendulum robot, but also can effectively
result optimal gain scale factor so that the controller can solve those problems more effectively
and more robust against disturbances and parameter uncertainties compared with other artificial
based optimization methods. This paper investigates more deeply the influence of membership
functions on the effectiveness of gain scale factor as well as the robustness of resulted controller.
It can be shown through the simulation that an optimal membership function can be found using
firefly making the gain scale factor small enough which is very good from the hardware
implementation point of view and in suppressing chattering- while still maintaining the robustness
against the parameter uncertainties. The robustness comparison between controller based on the
proposed optimal gain scale factor with other controllers are also shown in the simulation.