RIDE CONTROL OF SURFACE EFFECT SHIPS USING DISTRIBUTED CONTROL

A ride control system for active damping of heave and pitch accelerati ons of Surface Effect Ships (SES) is presented. It is demonstrated tha t distributed effects that are due to a spatially varying pressure in the air cushion result in significant vertical vibrations in low and m oderate sea states. In order to achieve a high quality human comfort a nd crew workability it is necessary to reduce these vibrations using a control system which accounts for distributed effects due to spatial pressure variations in the air cushion. A mathematical model of the pr ocess is presented, and collocated sensor and actuator pairs are used. The process stability is ensured using a controller with appropriate passivity properties. Sensor and actuator location is also discussed. The performance of the ride control system is shown by power spectra o f the vertical accelerations obtained from full scale experiments with a 35 m SES.