Research On The Control System For AC Servo-Drived Wave-maker

Wave-maker is a kind of facility to arouse different kinds of wave in the flume or basin to simulate the impact of natural wave on the construction. The data obtained from the experiments supply proof for the design of architecture or ship. This paper was just based on the establishment of the flume wave-maker in the laboratory of haven and coast engineering of Tianjin University. The system was mainly comprised of PC, motion controller, servo motors, drivers, wave-detector, data-gathering facility and some mechanical parts. The paper introduced the hardware and software of the whole system respectively including electric control, programming, human interface on the PC, etc. As to the wave-detector, first the circuit diagram was analyzed, to obtain the standard industrial voltage signal,the improved circuit was also proposed.The system of wave-maker formed a typical AC servo control system. As the executor of the system, the motors and how to control them were the key points. So apart from the above-mentioned work, the motor (PMSM) was also discussed in detail. First the structure principium and mathematic model were elucidated, then vector control for PMSM and the theory of SVPWM were expounded as key points. Also the process of the computing of SVPWM using Matlab was explained. Finally the whole system of PMSM combined with its control parts was established using Simulink according to the strategy of i d=0. The results of the simulation confirmed the feasibility and correctness of the strategy.On the other hand, the position synchronization of the motors was of great importance to the whole system. From this point of view, the paper also studied the strategies of how to synchronize multi-motors. Methods based on fuzzy logic and conventional ones were analyzed and compared. Furthermore, fuzzy controller based on parameter self-adjustable was applied to the system. Through the simulation of the system using different methods, it was obvious that the strategy based on the parameter-adjustable fuzzy controller can achieve better synchronization precision.Some experiments were done after the completement of the system, and the results show the quality of the system can satisfy the request of laboratorial flume.