The tilt angle estimation in the inverted pendulum stabilization task

This article is devoted to issues concerned with the task of stabilization of two wheeled balancing robot in a vertical position. This device is an inverted pendulum type object from the mathematical point of view. The key aspects of stabilization task are researched. The operation of the tilt angle estimation subsystem based on using accelerometer and gyro sensors is researched. The operation of the complementary filter used for fusing sensors data is considered. It is shown that this filter has a weakness which consists in that the accelerometer mid- and low-frequency distortions may go through the filter. The alternate technique of tilt angle estimation is proposed. This method is based on implicit using the encoder data which is used to estimate wheel rotation angle. The structure of the control system used this approach is given and the controller coefficients equations are presented. The issue of desired dynamics polynomial selection is considered. Finally the simulation and the real device operation result are shown.