Methods of Inverse Simulation for Nonlinear Ship Steering Systems Investigations

摘要

The paper describes the application of two inverse simulation methods based on continuous system simulation principles to a ship model which incorporates a rudder actuator submodel with saturation and rate limits. One approach depends on feedback principles while the other involves the use of an approximate differentiation method. If the actuator is operating in a linear fashion the two inverse simulation methods give very similar results. However, the differentiation method cannot be used with hard limiting and nonlinear oscillatory phenomena may cause problems with the feedback approach in such cases. An approximate two-stage procedure that avoids these difficulties but provides useful insight about the effects of rudder saturation and rate limiting is presented. Inverse simulation allows the onset of limiting to be detected and can provide insight about vehicle handling and manoeuvrability more directly than conventional simulation methods.