Modeling and second-order sliding mode control for a full three-dimensional ridable ballbot

Abstract

ABSTRACT The full 3D ridable ballbot (RB) system is a typical higher-order, multi-variable, underactuated, nonlinear, nonholonomic constraint, and strongly coupled control system. The dynamics of the RB also consists of uncertainties of the system parameters and unknown frictions. Such a complicated system requires a sophisticated control algorithm that can handle these difficulties to control the balancing and transferring of the RB. This study introduces a nonlinear robust control algorithm based on the sliding mode technique. The robust controller with sliding mode surfaces is designed to control the position of the ball on the floor and the angles of the body. The simulation and experimental results of the full 3D RB setup. The acquired results demonstrate the superior performance of the proposed controller. Meanwhile, the experimental performance of the proposed controller is validated on an actual RB.