Study On The Improvement Of High-speed Water-entry Model And Control Of Water-entry Trajectory Of Superbubble Navigation Body

The scientific research of super-bubble underwater vehicle has been attached great importance to by many countries in the world.The existence of vacuole has greatly reduced the friction resistance of super-bubble navigator in water.Driven by rocket engine,it can reach a very high speed,far exceeds the speed of ordinary navigator(such as torpedo).However,because the super-bubble underwater vehicle is subjected to very complex force from water flow in actual waters,it is difficult to control it.How to effectively control the super-bubble underwater navigator has always been a key problem for scholars all over the world.The longitudinal control of super-bubble navigator is a hot topic in the scientific research of underwater vehicle control.The main research directions are as follows:Firstly,the stress of the navigator under super-bubble water is analyzed.Based on the dynamic equations of the existing super-bubble underwater vehicles,the following water hole experiments and oblique water experiments are fully prepared.Then,the water hole experiment and the oblique water experiment of the super-vacuum solid model are carried out.In the water hole experiment,the cavitation under the condition of flowing water is controlled by servo motor,which makes the cavitation rotate at a fixed frequency and amplitude,observes and collects the cavitation shape data at different frequencies,and collects the internal and external pressure of the cavitation immediately.Test and analyze the data.In the oblique water experiment,the whole process of all the related experimental instruments and experiments is introduced in detail.In this experiment,the data acquisition is carried out by the measurement module inside the navigator,and the collected data information is analyzed.According to the trend of impact load in the whole process,the optimal water intake scheme is planned.Then,the previously created mathematical analysis model is improved.By comparing with several control methods such as fuzzy PID,the controller is designed using robust H∞basic theory.According to the created mathematical model,we have completed the design of the control system.Finally,the control algorithm is simulated and verified.as a result,the controller designed by the robust H∞ method can effectively control the trajectory of the super-vacuum navigator water entry,and the system is robust.