Simultaneous regulation and velocity tracking control of a two-wheeled self-balancing robot

In recent years, two-wheeled self-balancing robots have played an important role in personal transportation research. Presenting control algorithms for this category of mobile robots has always faced challenges due to nonlinear dynamics, structural and non-structural uncertainties, the dependence of model parameters on environmental conditions, and the presence of external disturbances. Therefore, the control of these systems has always been the focus of attention. One of the prominent control issues in this field is tracking the time-varying trajectories. In this paper, the motion control of a two-wheeled self-balancing vehicle is investigated. For this purpose, by designing a cascade control algorithm and the appropriate reference trajectories, the system will be controlled to follow the reference velocity profile while maintaining its stability. The main challenge in controlling this system is that two variables must be justified for the longitudinal control, one is the position or speed of the longitudinal movement of the system and the other is the pitch angle of the two-wheeled self-balancing robot. But the system has only one input to adjust these two variables, which complicates the control of the system to some extent. This issue has been investigated in the provided control methods and the adjustment solution has been investigated. The obtained results show the efficiency of the proposed controller in simultaneous trajectory tracking and maintaining stability.