Research On The Energy-Saving Optimization Strategy Of AUV

With the deepening of humans exploit the ocean,As an important tool for marine resources exploration and marine scientific exploration,Autonomous Underwater Vehicle(AUV)has developed rapidly.The scope of application is expanding and the types of work are becoming more and more complex,so the new requirements for AUV are put forward,which is expected to have longer operating hours and larger sailing distance.In order to meet the requirements for the arrangement of electrical equipment,AUV carries limited energy,Energy issues have become a key issue limiting the development of AUV.The most direct and effective way to solve energy problems is to increase battery capacity,but new battery technology is difficult to achieve breakthrough progress in a short period of time.Therefore,improving energy efficiency has become an effective method to reduce energy consumption and improve endurance.Optimization of AUV line design is an effective method to reduce navigation resistance and improve energy efficiency.In order to reduce the navigation resistance,an approximate model of resistance estimation is established by using experimental design and approximate model technology for water drop shape AUV,and a deterministic optimization of the approximate model for resistance estimation is carried out by using multi-island genetic algorithm.However,the design scheme obtained at this time does not take into account the influence of the random change of uncertainty factors on the optimization results.The reliability analysis of the design scheme obtained by deterministic optimization is carried out.The results show that when the design variable is disturbed randomly,The deterministic optimization design scheme will exceed the constraints and no longer meet the design requirements.Therefore,the uncertain optimization design of AUV profile line is carried out,and the design scheme which meets the requirements of quality and reliability is obtained.According to the energy consumption equation of AUV system,AUV energy consumption is related to cruise speed.Using energy-saving navigation speed can effectively increase voyage range and improve energy efficiency.The thrust coefficient and thrust function of propeller need to be obtained before optimizing the speed of energy-saving navigation.In order to obtain the thrust coefficient of propeller,the self-propelled performance of AUV is studied.The volume force model of Hough and Ordway is chosen to replace the real propeller,The interpolation principle and equal thrust method are used.Propeller open water calculation and the corresponding propeller open water characteristic curve to calculate the AUV self-propelled point and self-propelled performance related parameters.The response surface model of propeller thrust function is constructed by using experimental design and approximate model technique.The self-propelled performance parameters and thrust fiunetion of AUV are introduced into the energy eonsumption equation of the system.The gradient optimization algorithm is applied to optimize the energy consumption equation of the system,and the energy-saving speed of the system is obtained.With the expansion of the AUV application range5 the modularized and professional AUV has been developed,Multi-AUV collaborative operation system has emerged.When the AUV formation is sailing,it can optimize its formation and obtain the formation configuration with the least resistance,thus achieving energy saving.In order to reveal the characteristics of the pilot AUV and the AUV resistance changes during the formation voyage,the leader-follower double AUV formation configuration parameters were studied to obtain the single AUV resistance and fornation resistance to reduce the navigation area.The MGA is used to optimize the lead-following AUV double formation configuration in the area of drag reduction,find the formation configuration with the least resistance,and then further research will expand to the multi-AUV formation conflguration.It lays the theoretical foundation arnd technical support for AUV formation navigation.