Research on interconnection and damping assignment passivity-based control strategy for longitudinal vibration of high-speed elevator nonlinear car system

During operation, high-speed elevators experience significant longitudinal vibrations in their car systems due to variations in shaftway conditions and system parameter uncertainties, affecting ride comfort and safety. Existing active control methods often rely on absolute motion measurements, leading to high sensor costs and practical constraints. To address this issue, this study proposes an active control strategy based on Interconnection and Damping Assignment Passivity-Based Control (IDA-PBC), using only relative displacement and velocity feedback. A seven-degree-of-freedom longitudinal vibration model of the nonlinear high-speed elevator car system is first established. Then, based on the Port-Hamiltonian (PH) principle and relative-state reconstruction, the PH form of the car system is constructed. Through energy shaping and damping injection, the IDA-PBC controller transforms the original nonlinear system into a linear system with ideal damping performance, and the final control law depends only on the relative displacement and velocity of the car system. Conditions for global asymptotic stability are derived, and parameter selection criteria are proposed to enhance robustness against model parameter uncertainties. Comparative simulations with passive, Skyhook, and PID control are conducted under random excitation and emergency braking, and parameter sweep simulations are performed by varying key mass, stiffness, and damping parameters within ± 20% of their nominal values. The results show that the proposed method reduces the typical longitudinal vibration acceleration by more than 60% in the considered simulation cases, while the vibration responses remain bounded under the tested parameter variations. This study provides a theoretical and numerical basis for further developing active longitudinal vibration control strategies for high-speed elevators.