System Design And Sea Trials Of Ship Motion Control Testbed

Based on briefly describing the history of development of ship motion control and autopilots, The system structure of Ship Motion Control Testbed (for short testbed) which is sustained by the "211" Project funds of Dalian Maritime University are systemly expounded as a whole in this paper. The testbed with contracted size from an 8 tons tanker is built. The testbed is remotely controlled by a PC on shore and is self-propelled by DC motors. A PC/104 computer served as a central control unit for ship controller is mounted on the model ship. A HMR3000 magnetic compass made by Honeywell Company and a DGPS system are used to measure heading and positioning respectively. Twice of sea trials have been carried out triumphantly and interrelated trial results are given.Using Turbo C and PC/104 industrialized computer, the program module of core control and algorithm was fulfilled. Through the information collecting procedure, heading, rudder-angle, positioning data are collected and the remotely controlled commands are obtained. According to these data and by the special control algorithm, the control output rudder-angle is worked out. Based on optimal control theory and Nomoto's equation as the normal equation, according to weather, loading condition and Ship's speed, The algorithms of traditional PID, Gain Scheduling PID and Fuzzy-Neural Network course controller are designed systemly. Scheduling and navigation means of track controller are given in detail. Four patterns of sea trial are conducted which are turning test, Zig-Zag test, course keeping and track keeping.Using Visual C++, completing the program module of remote control and measure by radio modems. API serial communication, Windows multithread and ADO database are adopted for DBMS.Using this testbed, all kinds of ship motion controllers and autopilots can be tested. In contrast to real shiptrial, the testbed can save expenses and decrease fatalness largely. In contrast to pure system simulation of computer, the testbed can obtain more actual data systemly. It has been applied in the research of ship motion control and has widely applied foreground. The testbed wined nicer appraises of experts and obtained the first-class award in the "Tiaozhan Cup" science and technology opus contest all over country.