Optimization Design Of Large Multi-direction Wave Maker Control System

How to simulate the random motion phenomenon of sea waves for improving the accuracy of experimental research has always been a key problem for domestic and foreign hydraulic model experiments.Multi-directional wave maker are closer to the real sea waves because of their ability to generate multi-directional irregular waves.Therefore,they are highly concerned by the majority of marine engineering researchers and have become one of the necessary and important equipment for marine engineering laboratories.The development of wave maker has been consistent with the requirements of offshore experimental technology.With the rapid development of modern science and technology,the wishes of the deep exploration and exploitation of marine resources is becoming more and more,so the requirements for the refinement level of experiments are also becoming higher and higher,which leads the experimenters to put forward more and more strict requirements for the quality of the simulated waves in the model test.The satisfaction of these requirements will not only affect the structural changes of the wave maker but also greatly increase the computational load and cause the computational load problem.In order to solve the contradiction between the current wave maker technology and the demand of offshore engineering,this paper will improve and optimize the existing large multidirectional wave maker system from the perspective of control system optimization,which will build a foundation for the development of the next generation of largescale multidirectional wave maker equipment with higher computational complexity.Multi-axis,large computation and high precision and stability control are the three basic characteristics of the new generation wave maker.Therefore,the traditional wave maker control method of "single PLC controller + driver + motor" will also affect the further improvement of wave generation level due to the limitation of control axis number and computing capacity.For this reason,this paper adopts the modern high performance computing power and with a new type of soft PLC controller was used to replace the wave machine are widely used in traditional PLC controller design,at the same time for a new generation of plate wave institutions built based on EtherCAT industrial Ethernet controller group control structure,control the synchronization between the controller and grouping problem,put forward the control wave machine clock synchronization method,including the same controller multi-axis synchronous control between design and the design of the task clock synchronization between different controllers.At the same time,on the basis of the control structure constructed in this paper,the trajectory interpolation method is explored in combination with the motion control technology to solve the sliding problem of the moving track of the wave-making plate,and on this basis,a data interpolation method suitable for the current demand of wave-making control is designed.Next,aiming at the problem of wrong wave excited by wave generator on and off,this paper deeply studies the calculation method of motor start-stop control curve,and designs cosine wave start-stop control curve on this basis.Finally,the control software is designed based on the newly constructed multi-controller and multi-board wave-making control structure,and the coordination control efficiency of the multi-board wave-making machine and the expansion and upgrading requirements of the wave-making system in the future are considered in the design process.This paper takes the large-scale multi-directional wave maker currently facing the offshore engineering laboratory as the background,and conducts the control system design and problem research in a clear and modular manner.In the entire research and design process,the control structure of the wave maker is divided into two parts: real-time and non-real-time: the real-time part focuses on the accuracy of clock synchronization control and the high efficiency of data interpolation;the non-real-time part focuses on the smooth operation of wave making control and system stability.Finally,a new type of multi-plate wave maker test prototype was built in the State Key Laboratory of Coastal and Offshore Engineering,and the effectiveness of this work was verified through experiments.Among them,the synchronization control accuracy,system performance and reliability of the multi-controller system In terms of performance,it has reached the design requirements of the new generation wave maker control system.The work of this paper will lay a solid technical foundation and provide equipment guarantee for more precise and accurate wave spectrum simulation in the future.