Active nonlinear partial-state feedback control of contacting force for a pantograph-catenary system

Area of Science:

• Mechanical Engineering
• Control Systems Theory
• Applied Mathematics

Background:

• Pantograph-catenary systems are crucial for power collection in electric trains.
• Maintaining stable contact force is essential for reliable operation and minimizing wear.
• Existing control methods face challenges with system nonlinearities and unmeasurable states.

Purpose of the Study:

• To design a robust nonlinear partial-state feedback control for a 3-DOF pantograph-catenary system.
• To achieve accurate tracking of the contact force reference profile.
• To address challenges posed by system nonlinearities and unmeasurable states.

Main Methods:

• Utilized the backstepping approach for control design, transforming the system into a triangular form.
• Employed a high-order differentiator to estimate unknown time derivatives of the elasticity coefficient.
• Proposed an observer to reconstruct unmeasurable system states.

Main Results:

• The proposed nonlinear partial-state feedback control ensures the contacting force tracks its reference profile.
• Tracking error of the contacting force is theoretically proven to be ultimately bounded with tunable bounds.
• Numerical simulations validated the theoretical findings and demonstrated the control's effectiveness.

Conclusions:

• The developed control strategy effectively manages the nonlinear dynamics of the pantograph-catenary system.
• The approach provides a robust solution for achieving precise contact force control.
• The method offers tunable bounds for tracking errors, enhancing predictability and reliability.