A new triple-stage stabilizing control method for two-wheeled inverted pendulum robots

Abstract

In the present paper, we propose a novel triple-stage stabilizing control approach for a two-wheeled underactuated inverted pendulum robot, which can drive the robot to move from its initial pose/position to the desired one while maintaining small pendulum tilting angle during the overall transportation process. The control approach consists of three stages, i.e., two pure rotation stages (Stages 1 and 3) and one straight line translation stage (Stage 2). More precisely, during Stage 1, the robot is driven to undertake a pure rotation movement and point to the desired position accurately. Then, we develop a nonlinear control law to drive the robot to move along the straight line connecting its initial and desired positions while suppressing the unactuated tilting angle in Stage 2. Finally, after Stage 2, when the robot reaches the desired location, another pure rotation controller is applied to regulate the robot orientation error to zero in Stage 3. Rigorous stability analysis is provided to support the theoretical derivations. Numerical simulation studies are included to verify the effectiveness of the proposed control approach.