The design, construction, and closed-loop control of an experimental platform of the Inertial Inverted Pendulum Inertial Underactuated System is presented. The nonlinear dynamics of the system were studied using the Euler-Lagrange method for the control design and by the recursive Newton-Euler method for the mechanical analysis. Torque requirements for the actuator were derived through the design, simulation, and tuning of a hybrid controller composed of a linear and a nonlinear controller.