A Problem and Solution of the Motion Control System
Abstract The "Rainbow" is a fully submerged hydrofoil catamaran and has a motion control system named APF (Auto Pilot on Foils). Although the original APF could eliminate wave-excited motions, there remained a certain level of vibration. To reduce the vibration, some improvements were enforced on the APF for the "Rainbow 2" . The effectiveness of the improvements were verified during the sea trials of the "Rainbow 2" , and it was clarified that the vibration levels of the "Rainbow 2" were reduced to about 10% of those of the original "Rainbow" .
The paper presents an analytical approach to extract machine parameters for creating a machine model under stator turn fault condition for a surface permanentmagnet (SPM) motor. The development of an accurate model of turn faulted SPM motor is essential to study motor and drive behavior under fault conditions, and to develop effective turn fault detection algorithms. The main contribution of the paper is to propose a completely analytical approach to modeling turn fault in SPM machine, which has not been reported so far in literature. Further to validate the analytical method, finite element (FE) analysis of an SPM motor with stator turn fault is performed and the results are compared with the analytical prediction. It is shown that the proposed model achieves good match with the FE results.