Observer-Based Controllers for Two-Wheeled Inverted Robots with Unknown Input Disturbance and Model Uncertainty

Table 1

TWIP’s notations and parameters.

Notation		Definition
		Position of the TWIR
		Pitch angle of the pendulum body
		Yaw angle of the TWIR
		Distance from the left to right wheels
		Length from the center of the pendulum to the wheel axis
		Radius of wheels
		Mass of the pendulum (without wheels)
		Mass of left (right) wheel
J		Mass moment of inertia (MOI) of the wheel with respect to (w. r. t.) the wheel axis
		MOI of the wheel w. r. t. the vertical axis
,		Motor’s left (right) torque
		Coefficient of viscous friction on wheel axis
, ,		MOI of the pendulum w. r. t. the frame at the center of the pendulum