Influences of Feedback Gains on Vehicle–Bridge Coupled Vibration for a Mid-Mounted Maglev Train

Abstract

Levitation control systems play a vital role in ensuring the operational performance of medium and low speed maglev trains. Improper gain values may induce excessive vibrations in vehicles and bridges, potentially leading to collisions. This research investigates the influence of feedback gains on the levitation subsystem and the vehicle-bridge coupled system, leveraging a newly designed maglev vehicle equipped with mid-mounted suspension and a state feedback control strategy. A dynamic model of the vehicle-bridge coupled system was developed, incorporating control strategies, track irregularities, and bridge flexibility, and was validated through experimental data. The dynamic responses of the bogie and bridge under varying gain values were analyzed in-depth. By examining pole locations and frequency responses, the mechanisms through which each gain impacts the coupled system were clarified. The study identifies that gains associated with acceleration, velocity, and displacement each have unique stability domains that interact with one another. To maintain system stability, the gains must adhere to the Routh-Hurwitz stability criterion while fulfilling specific bandwidth and damping requirements. Gains set too low or too high may result in levitation failures. Recommended ranges for these gains are as follows: acceleration (0.2–0.6), velocity (30–100), and displacement (5,000–10,000). These findings could provide valuable guidance for designing control systems that enhance the stability and safety of maglev train operations.