This article describes universal tracking control method. It is based on model linearization in every point of trajectory. Tested device is an inertial wheel pendulum (IWP). This is an underactuated nonlinear object - two degrees of freedom (angle from vertical and angle of rotation of electric motor) and one actuator (current). The linear quadratic regulator (LQR) and the model of the object are analytically considered. Many experiments are presented and confirm proper and stable operation of the system and some constraints.