Modelling and stabilization of a series of self-balancing two-wheel vehicles

This article deals with the modelling and control of a series of two-wheel vehicles connected via linear springs. The wheels of the two-wheel vehicles are connected to the side of the chassis via gear boxes and motors and rotate around the same axis. A non-linear dynamics model is derived for the system assuming that the vehicles move in tandem on a straight path. The system is underactuated and inherently unstable. A control scheme is designed to stabilize the vehicles all at the same time. The control technique used in this work is passivity based and guarantees the asymptotic convergence of the states towards stable trajectories. The non-linear control law is used to bring the states near the desired positions; subsequently, a second linear controller takes over to make the states converge towards the desired positions. The simulation results presented in this article show the success of the control schemes in controlling a system with two two-wheel vehicles.