Abstract
In this study, suppression of vibrations over the body aimed by the controller at the second suspension system between the railway vehicle body and bogies to increase passenger comfort due to vibrations existed at the train body have an important effect over passenger comfort. The investigated vehicle is a high-speed train that has 10 degrees of freedom. To suppress the vertical vibration, model reference adaptive control is designed. Improvements at the responses of the system are achieved by the controller design despite the model to have parametric uncertainties where at the second suspension systems. The effectiveness of the suggested controller was shown in time and frequency domains.