A novel speed optimisation scheme for unmanned sailboats by sliding mode extremum seeking control without steady-state oscillation. (14th May 2022)

• Record Type: Journal Article
• Authors: Shen, Zhipeng; Fan, Xuechun; Yu, Haomiao; Guo, Chen; Wang, Saisai
• Is Part Of: Journal of navigation. Volume 75:Number 3(2022)
• Page Start: 745
• Page End: 762
• Publication Date: 2022-05-14
• Subjects: unmanned sailboats -- speed optimisation scheme -- extremum seeking control -- sliding mode -- without steady-state oscillation; Navigation -- Periodicals; 623.8905
• DOI: 10.1017/S0373463321000667
• Languages: English
• ISSNs: 0373-4633

Abstract

Abstract: This paper proposes a novel speed optimisation scheme for unmanned sailboats by sliding mode extremum seeking control (SMESC) without steady-state oscillation. In the sailing speed optimisation scheme, an initial sail angle of attack is first computed by a piecewise constant function in the feed forward block, which ensures a small deviation between sailing speed and the maximum speed. Second, the sailing speed approaches to maximum gradually by extremum search control (ESC) in the feedback block. In SMESC without steady-state oscillation, a switching law is designed to carry out the control transformation, so that the speed optimisation system carries out SMESC in the first convergence phase and ESC without steady-state oscillation in the second stability phase. This scheme combines the advantages of both control algorithms to maintain a faster convergence rate and to eliminate steady-state oscillation. Furthermore, the strict stability of the speed optimisation system is proved in this paper. Finally, we test a 12-m mathematical model of an unmanned sailboat in the simulation to demonstrate the effectiveness and robustness of this speed optimisation scheme.