Nonlinear control with friction compensation to swing-up a Furuta pendulum

Area of Science:

• Robotics and Control Systems
• Nonlinear Dynamics
• Friction Modeling

Background:

• Traditional energy-based controllers struggle with inverted pendulums affected by friction.
• Existing research often simplifies friction to static models due to stability analysis complexities with dynamic friction.

Purpose of the Study:

• To develop and validate a nonlinear controller for complete swing-up of a Furuta pendulum with dynamic friction.
• To address limitations of existing controllers in handling dynamic friction in pendulum systems.

Main Methods:

• Modeling the Furuta pendulum dynamics incorporating dynamic friction using the Dahl model.
• Modifying an energy-based controller with friction compensation and a nonlinear observer for state estimation.
• Employing the direct Lyapunov method for closed-loop stability analysis.

Main Results:

• A novel nonlinear controller effectively compensates for dynamic friction in the Furuta pendulum.
• The proposed controller achieves complete swing-up within a feasible experimental timeframe.
• Stability of the closed-loop system is rigorously proven using Lyapunov stability theory.

Conclusions:

• The developed controller demonstrates superior performance in swinging up a Furuta pendulum with dynamic friction compared to existing methods.
• Friction compensation is crucial for achieving robust control of systems with dynamic friction.
• Experimental validation confirms the controller's effectiveness and stability in real-world applications.