PARAMETRIC IDENTIFICATION OF SHIP MODEL BY SYMMETRIC MOTIONS AROUND ROLL ANGLE WITH TAUTWIRE REFERENCE POSITION SENSOR

• Published in: Nauchno-tekhnicheskiĭ vestnik informat͡s︡ionnykh tekhnologiĭ, mekhaniki i optiki mekhaniki i optiki, 2019-03, Vol.19 (2), p.347-359
• Main Authors: A. S. Alyshev, A. E. Kovalenko, D. V. Romaev, V. G. Melnikov, A. M. Titov
• Format: Article
• Language: English
• Subjects: accelerometer; adaptive control; consecutive compensator; dynamic position; flywheel oscillator; parametric identification; ship model; sliding mode control; symmetric program motions; tautwire reference sensor
• ISSN: 2226-1494; 2500-0373
• DOI: 10.17586/2226-1494-2019-19-2-347-358

The paper presents a new method of identifying the parameters of the ship model using symmetric motions. The subject of research is the improvement of the parameter identification accuracy under the condition of complete uncertainty of mathematical models of the ship hull and reaction wheel device, as well as the development of a new position reference sensor for ship models in the form of a tautwire inclinometer. Small symmetric reversing accelerating-decelerating program motions about roll angle were used, while the model of the vessel was fixed in the test basin and the movement in other degrees of freedom was excluded. To create the programmed motions, an electric motor with a flywheel mounted on the vessel was used. The control system has been developed as an application of a hybrid adaptive controller consisting of a consecutive compensator and a sliding controller, and their parameters are adjusted taking into account the restriction on their maximum values. A new approach involves carrying out two experiments. During the main experiment, the program motions of the model occur about the roll angle, while the additional experiment involves programmed motions of the flywheel around the flywheel rotation angle. The program trajectory of the flywheel was obtained according to the results of the main experiment. Illustrative results are given showing the essence of the proposed method and the results of the control system with harmonic oscillation as a reference trajectory. The operating principle of the cable inclinometer is considered, and a brief overview of the existing technical solutions is presented concerning the part of the structure for the desired cable tension support. Calculation formulas are given determining the position of a vessel with a dynamic positioning system in the case of measuring angles in the cable inclinometer using potentiometers or accelerometers. The results can be useful when carrying out model tests or for full-scale vessels with dynamic positioning systems.