Research On Semi-physical Simulation Platform Of The Ship Autopilot System

There are fewer people who research on the semi-physical simulation platform of the ship autopilot system in our country. Semi-physical simulation is a platform which ranges between physical simulation and pure mathematical simulation. It has real-time and high speed characteristics, at the same time, semi-physical simulation can close even to the physical simulation results. Therefore, constructing the semi-physical simulation platform of the ship autopilot system has very important significance for the engineering application.The ship autopilot system mainly includes control, communication and monitor. This paper makes a study about the autopilot system from the three parts, the specific contents are as follows:â‘ Autopilot control mostly remain at the stage of PID control for the domestic, but the autopilot system is a nonlinear system, PID control is difficult to achieve good control effect. This paper introduces the fuzzy variable structure control method, designes fuzzy sliding mode controller based on exponential approach law, it has robust, simple structure, easy to implement. We make a comparative analysis to sliding mode variable structure control and fuzzy sliding mode control in MATLAB / Simulink. Simulation results show that the fuzzy sliding mode control based on exponential approach law has strong robustness, at the same time it can effectively eliminate chattering, ship Autopilot system achieve better control effect.â‘¡The work environment of the Ship is poor, while the equipment performance and reliability requirement are relatively high. According to the characteristics and development trend of shipping automation, the paper designs of industrial Ethernet and CAN bus communications platform. CAN bus can work in harsh environments, has Strong anti-electromagnetic interference capability. It is an international marine standard. Simulation results show that this communication platform has better real-time and reliability.â‘¢If we want to realize PC real-time monitoring of the autopilot, we must solve the problem of communication between PC and autopilot. Therefore, the platform uses the OPC server and ifix configuration software. The ifix configuration software has easy configuration and real-time characteristics. Simulation results show that ifix configuration software realizes the PC real-time monitoring of the autopilot. Finally, the paper uses computer, data acquisition cards, analog output cards, DSP controller and other hardware to constract a semi-physical simulation platform of shipping automation system. On the semi-physical simulation platform we have realized the overall operation and real-time monitoring of the autopilot system.