Research On Fault Simulation And Diagnosis Equipment Of Ship Control System

Ocean is closely related to national security and development, and many countries compete to develop various types of ships. In recent years, the large-scale, energy-saving and high environmental protection of ocean-going vessels has become a trend. In order to improve the economic benefits of ships, we must improve the effectiveness, safety, reliability and stability of the ship control system. Ship control system requires the ship can keep running at a certain speed without external distrurbed environment. The traditional fault detection and removal methods are difficult to achieve fast and accurate results, thus tolerant control technology into the field of ship control becomes a research focus. At present, domestic research institutes of the ship control system focuse on fault-tolerant control method, and there is no support of fault injection platform. Therefore, this article is based on the demand for ship control technology analysis, proposing a scheme of software and hardware implementations of fault simulation and diagnosis equipment which provides support for ships' fault-tolerant technology. The main research aspects are arranged as following:(1) By analyzing advantages and disadvantages of fault injection method implemented in software, simulation-based fault injection method and physics-based fault injection method, this article selects physics-based fault injection method and implements in hardware combining with the fault of ship control system that may arise in operation. For traditional fault circuit access system more cumbersome and time-consuming and other shortcomings, this article describes the earbud connector works and presents real-time fault injection method based earbud connector. This approach makes multiple types of fault circuit normalized to unity cabinet, and generates a fault injection device. Using earbud connector connected to the chassis when the system needs to inject faults, it ultimately improves the flexibility and reliability of the system.(2) The implementation of specific hardware circuit of fault simulation for ship control system has been designed. Fault types including the voltage fault used to simulate electromagnetic interference string into the voltage signal transmission process, the current fault used to simulate electromagnetic interference string into the current signal transmission process, the impedance fault used to simulate various communication faults occurs when signal transmission, and the switch fault is used to simulate the system switch malfunction. These fault circuits are testified by experiment and experimental results which demonstrate the effectiveness and correctness of fault injection circuit.(3) The paper designs a Delphi-based computer system for fault settings, giving the fault settings' main program and the channel search, fault injection, back to normal, load recording four functions implemented program flow chart. And it also designes the controller based on DSP and FPGA fault injection system, giving a detailed flow chart of the main controller DSP. Both of them constitute the software solutions of failure setting and injection system.(4) Local control unit is an important part of the ship control system fault simulation and diagnosis, the paper elaborates its basic principle and proposes a fuzzy recursive integral PI control method for valve-controlled steering system of ships, which combines the advantages of fuzzy control technology and recursive integral PI. The experimental results show that this control method can achieve no error control. For acquired signals may interfere with the ship running environment, the paper proposes an improved method of digital filtering that suitable for ship control systems, the experimental results also show that the filter can achieve the desired effect.(5) The hardware and software of the local control unit is designed. The hardware using IPC and CPCI boards to achieve data acquisition, control execution, communication, display and other functions; software using Delphi design, shows the data acquisition, control execution, communication and display program flow chart.This paper developes a fault simulation and diagnostic equipment for ship control system. It can simulate all kinds of faults that may occur in the operation of the ship under the real environment. The local control unit collects real data access fault setting and injection device for signal superimpose, then the signal after superimposed on the fault signal is sent to a fault-tolerant computer for fault-tolerant computing, local control unit receives the fault-tolerant computer control instructions to complete closed-loop control of the pump control, valve-regulated and other systems. Therefore, the proposed fault simulation and diagnosis equipment to improve the security and the stability of the ship is of great significance.