Study On A Ship Motion Attitude Optimization And Control Coupled With Photovoltaic Characteristics

With the continuous development of society and constant increase of non-renewable energy consumption,the improvement of ecological environment becomes urgent,and energy saving&emission reduction gradually develops into a hot topic in academic circles.Shipping companies all over the world have also attached great importance to this field,and are committed to developing new technologies and methods to reduce existing energy consumption and to develop new eco-energy sources.Under this context,solar energy and wind energy,as two representative green energy sources,have gradually become important energy sources in the ship industry.Between the two,solar energy,as a new type of pollution-free energy of which we need not worry about exhaustion for a long time in the future,has become the focus of energy research.Scholars from all over the world are discussing how to use solar energy into ships to reduce the emission of hazardous gases from ships.The main contents of this paper are as follows:Firstly,through a force analysis of the ship on the sea,a mathematical model of Fin/Rudder Roll Stabilizations was deduced and established.At the same time,by studying the solar radiation principle and the influence of ship moving posture on the ship's photovoltaic power generation system,a mathematical model of the output energy of photovoltaic power system on board was set up.Secondly,the performance indexes of the stabilizer fin and the rudder systems were analyzed and established successively.For the stabilizer fin system,four aspects were analyzed(i.e.roll angle variance,fin angle variance,fin angle rate and load energy consumption)and performance indexes were established.For the rudder system,it was studied the additional energy consumption caused by the resistance reduction and heading error,and extra energy consumption caused by the high steering frequency.The performance indexes of ship system with photovoltaic characteristics were comprehensively considered in terms of energy consumption,stabilization effect and heading accuracy,and a multi-objective function of ship posture optimization with photovoltaic characteristics was also proposed.Thirdly,by using two kinds of intelligent algorithms(i.e.the previous multi-objective genetic algorithm,and the multi-objective cuckoo algorithm newly proposed),parameters K_P,K_I andK_D of PID were automatically adjusted aiming at optimizing performance indexes of ship system with photovoltaic characteristics,and the weight coefficient in the performance indexes and function value of the system fitness were improved.Finally,a simulation analysis was carried out on the function value of system fitness,the three parameters of PID and the performance indexes of ship system with photovoltaic characteristics by using different multi-objective algorithms.The simulation results proved that the multi-objective cuckoo algorithm not only improved the stability of convergence but also quality of optimal solution,and prevented the local optimal solution in the iterative process,which led to the failure of optimization.By using the multi-objective cuckoo algorithm,the ship's stabilization effect could be improved,the heading control accuracy could be optimized and the energy consumption of the system could be lowered to a certain extent.Meanwhile,the energy output of the photovoltaic power system on board could also achieve the desired effect in the initial design.With the simulation analysis,we can learn that this topic is an expansion of new energy sources used in ships and has very high research value.