Consider the experimental setup of an inverted pendulum shown in Figure P9.25
Suppose that direct fuzzy logic control is used to keep the inverted pendulum upright. The process measurements are the angular position, about the vertical (ANG) and the angular velocity (VEL) of the pendulum. The control action (CNT) is the current of the motor driving the positioning trolley. The variable ANG takes two fuzzy states: positive large (PL) and negative large (NL). Their memberships are defined in the support set [-30°, 30°] and are trapezoidal. Specifically:
