Low-Complexity Robust Tracking Control of Pendulum Systems Under Output Constraints

The problem of control for trajectory tracking in pendulum systems with output constraints and external disturbances is addressed. A robust tracking control approach is constructed on the foundation of barrier functions. Unlike the application of Lyapunov stability theory, this study constructs the control performance via the dialectic of contradiction to show that the suggested control strategy exhibits inherent robustness against uncertainties in model parameters and external interferences. Therefore, the common tools for parameter identification, function approximation, or disturbance estimation are not invoked, yielding a control simplicity. It turns out that the reference was tracked by the system output without violating the prescribed constraint. The proposed control approach was illustrated to be effective through the simulation results.