Suppression of Oscillations of a Two-Wheeled Balancing Robot

The balancing two-wheeled robots are clear proof of the triumph of technology and programming, as well as the theory of automatic control. Developments in this area are carried out in all leading laboratories of robotics. Achievement of high speed and high precision always demonstrate the best professionalism of developers. These developments are relevant due to the applicability of the results in many areas of technology. To measure the angle of deviation from the equilibrium axis, sensors of different nature are used. The most promising for these purposes is MEMS-gyroscopes characterized by small dimensions, high reliability and speed. These sensors are successfully used for these purposes, but it have a characteristic nonlinearity leads to self-oscillations in an equilibrium state. This oscillatory mode cannot be eliminated by any optimization of the PID controller. This paper proposes a method for eliminating these auto-oscillations by applying oscillations from this sensor relative to the frame of the balancing robot. This feature provides the dynamic linearization of the sensor transfer characteristic due to the high-frequency component at the sensor output, which is generated by the mechanical deviation of this sensor, while the averaged signal has the required smooth dependence of the output varieties on the input value changes. We propose to introduce the deviation by a MEMS-actuator based on then electromagnetic hanging, a piezoelectric drive, or a different nature drive. The possible simplified structure of one device for introducing a deviation to the equilibrium sensor for the balancing robot is carried out. The method is investigated by mathematical modeling. We show its high effectiveness in design the practice technical solution.