A Study on Unified Automatic Control System for Longitudinal Motion of Jetfoil Based on Optimal Servo Theory

Abstract

Current Jetfoil control has been made by platform and contour mode selection and by manual input of fore-foil depth according to sea conditions by human operator, which cause overload and may be difficult for operators. This requires the further automation in the control system.
In this paper, authors propose unified automatic control system (ACS) which is based on optimal servo theory and eliminates human operation in ACS. The reference input signal in the servo system was modified to the sea conditions to achieve unification of platforming and contouring. First, optimal servo system (OSS) was designed to keep the fore and aft foil depths in waves to find that the sole OSS was still sluggish. Therefore, authors added proportional and differential element in inner feedback loop in addition to the modification of reference input.
The MOSS+MRI, which represents modified optimal servo system (MOSS) and modification of reference input (MRI), was confirmed the good control performance in the wide range of waves through simulation.