Research on real-time distributed simulation syste

Development of sea state real-time distributed simulation system based on Mitsubishi products

Abstract: This paper introduces in detail the use of large-scale Ansh PLC and compact FX2N PLC of Mitsubishi Electric Company and their corresponding output function modules, fr-540 frequency converter, and adopts the field bus CC link with high transmission rate and good reliability to construct a set of real-time and reliable sea state real-time distributed simulation system. The development of this system provides a practical hardware in the loop simulation platform for the development of marine ships, which saves a lot of test funds and reduces the material and human resources required for the test. At the same time, to a certain extent, it can also carry out the simulation test of marine energy development, filling the gap in the industry

key words: PLC hardware in the loop simulation CC link

1 design background

the swaying posture of the ship in the sea and the anti wind and wave performance of the hull are of great significance to the stability and safety of the ship's navigation. The different motion posture of the hull in the ocean: heeling, trim, up and down represent different sea state levels, and the seaworthiness level of the ship is an important indicator for ocean ships. Therefore, when designing ships, especially ocean going ships and ocean ships, we must scientifically calculate the wind and wave resistance grade of their hull. However, the calculation is only a theoretical value, which must be corrected by many sea wind wave tests. Such an experiment is not only time-consuming and laborious, but also a waste of a lot of financial resources. In order to reduce expenses, some units have reduced the number of sea wind wave tests to the minimum, which not only affects the integrity of the test data, but also some data are not necessarily complete. In order to avoid this phenomenon and make the design of ocean and ocean ships more scientific, time-saving, labor-saving and financial saving, we use the large practical PLC Ansh of LingDian automation and the economical compact FX2NPLC, fr-e540 frequency converter, and use CC link Fieldbus to develop a set of 50 meter long, 30 meter wide and 6 meter deep pool wave making system, which can simulate the wind and waves of real-time sea conditions, The hardware in the loop simulation system platform for ship design is realized, which can not only provide ship design units and ship certification units with hardware in the loop real-time simulation tests, provide ship design with test site data close to the actual sea conditions in the global Li ion battery cathode material market, but also carry out the development and research of wave power generation devices for marine development units. Such a hardware in the loop distributed simulation platform system has been formed abroad in the 1990s, and is currently being trial produced in China's ship design units

2 system composition and design

2.1 system composition

in order to simulate the wind and waves, current, wave path and wave height of sea conditions in real time, the wave making system consists of the following subsystems

1) wave making subsystem: the pool is equipped with three sets of double push plate high-power wave makers and low-power wave makers. Different combinations of large and small wave makers can produce long peak waves propagating longitudinally, with a maximum wave height of 0.3 meters, which are controlled by computer program, It can generate regular waves or irregular waves required by model tests

2) flow generation system: the pool is equipped with a set of high-pressure water spray and flow generation system, which is evenly covered with water spray pipes on both sides of the pool wall. The water pump absorbs water from the thick pipe and sprays out from the dense water spray pipes after pressurization, resulting in uniform water flow in the pool. The system can generate longitudinal flow and transverse flow, with a maximum velocity of 0.1 M/s. In addition, a local flow making system is also configured to meet the needs of high-speed water flow and tests in different directions

3) air making system: configure a set of movable blower air making system. The maximum wind speed can reach 5 meters/second, and the wind spectrum can be simulated through the computer control system

4) trailer system: during the towing test, the towing test of upstream, downstream and transverse waves can be carried out, and the towing test of oblique waves can also be carried out by adjusting the X and Y directions

5) pool filtration system: the pool is equipped with a mechanical filtration system

6) wave elimination system: a grating wave elimination beach with a certain inclination is set on the opposite bank of the wave maker to absorb waves and prevent reflected waves

2.2 system design

in order to realize the above functions, the system adopts the concept of layering and dividing units to realize the real distributed control of the system. Among them, the wave making subsystem, the current making subsystem and the wind making subsystem can be controlled by two PLCs respectively. The waves of the sea state include large waves, small waves and ripple waves. In order to truly simulate the characteristics of the sea state, in addition, the waves of the high head and large sea are controlled by ans PLC, and the small waves and ripple waves are controlled by FX2N PLC. The flow generation subsystem is similar. Only in this way can we simulate two of the sea conditions. We can see the booming of the automotive industry in the future. There are many small high-end waves in the big wave. The process of wave generation is as follows: the analog output function module of PLC outputs a control signal of 0 ~ 10V to control the output frequency of fr-e540 frequency converter. The frequency converter controls the speed of the three-phase asynchronous motor in real time. The motor drives the slurry sheet of the wave maker to hit the water surface. The different speed of the motor results in different wave path and wave crest between the two wave heads. In this way, the different speed of the three-phase asynchronous motor corresponds to different wave head, wave path and wave crest, Therefore, different speed combinations of two three-phase asynchronous motors can reproduce and simulate different sea conditions in real time. The flow generation system is also controlled by the combination of Ansh PLC and FX2N PLC to form different water flow energy. The air generation system is realized by the high-power fan controlled by Ansh PLC

in order to improve the reliability, the manual standby speed regulation system is also designed in this control system to ensure that the wave making will not be affected in case of computer failure. When the computer fails, the switching device switches to the manual standby speed regulation system without manual intervention. The operator can adjust the speed of the frequency converter through the potentiometer to maintain the normal wave making process. The system configuration of three local control units composed of Ansh PLC, FX2N PLC, fr-e540 frequency converter and three-phase asynchronous motor, server composed of PC and human-computer interaction server architecture is shown in Figure 1. The configuration diagrams of Ansh PLC and FX2N PLC are shown in Figure 2 and figure 3

Figure 1: architecture diagram of simulation platform

cast composites only need to premix carbon fiber and resin 2.2.1 Ansh PLC characteristics and configuration

a1sjhcpu is the most economical CPU component in Ansh series. A1sjhcpu is unique in that its CPU, power supply and substrate are integrated, which significantly reduces the manufacturing cost. Ansh adopts Mitsubishi Shun, which is specially developed by Mitsubishi for sequence control and mathematical operation