Robust Stabilization of Underactuated Two-Wheeled Balancing Vehicles on Uncertain Terrains with Nonlinear-Model-Based Disturbance Compensation

Two-wheeled inverted pendulum (TWIP) vehicles are prone to lose their mobility and postural stability owing inherently unstable underactuated dynamic characteristics, specifically when they encounter abruptly changed slopes or ground friction. Overcoming such environmental disturbances is essential realize an agile TWIP-based mobile platform. In this paper, we suggest a disturbance compensation method that compatible with unmanned TWIP systems in terms of the nonlinear-model-based observer, where model transformed fully actuated form by regarding gravitational moment as supplementary pseudo-actuator counteract pitch-directional disturbances. Consequently, it enables us intuitively determine input two wheels pitch reference accommodating uncertain terrains real time. Through simulation experimental results, effectiveness proposed validated.