Study On Controllable Wing Mechanism Of Hybrid Underwater Gliders With Controllable Wings

Hybrid underwater gliders(HUGs)are a new type of platform for monitoring the ocean.They integrate the advantages of traditional autonomous underwater gliders(AUGs)and autonomous underwater vehicles(AUVs)and they can meet the demand of various marine environmental observations.They have two typical modes of operation: gliding mode and AUV mode.In glide mode,they complete saw-tooth path using the buoyancy-driven system and attitude adjusting unit and have long endurance;in AUV mode,they can cruise rapidly with the help of propeller.However,motion of the two working modes is quite different.In glide mode,it requires wings with large lift-drag to provide enough lift to improve glide efficiency.While in AUV mode,the wings will increase the drag,and lead to weak maneuverability.Studying HUG with controllable wings can effectively address the issue.The glider can adapt itself to different working modes through changing wing configuration.So the HUG can achieve optimal flight performance for different operating modes.Based on actual demand for variable wing configuration for HUG,a new planar linkage mechanism was designed.It can change aspect ratio and sweep angle of the wing.Flight performance of hybrid underwater glider can be improved through wing deformation according to different working modes.The main contributions are as follows:(1)According to the requirements of wing configuration,a new planar two degrees of freedom link mechanism was proposed.The output rod can achieve translational and rotational motion,changing aspect ratio and sweep angle of the wing.The wing configuration system was integrated to the glider by designing flooded compartments segment.(2)The kinematics and dynamics analysis of the controllable wing mechanism was conducted.Through forward kinematics analysis,variant function of the wing was verified.Given movement laws for the output rod,the control law curve of the motor was gotten through inverse kinematical analysis.Kinetic analysis and simulation of controllable wing mechanism was completed.(3)Based on computational fluid dynamics method,strategy of changing the airfoil profile of the HUG was studied,the influence of aspect ratio and sweep angle of the wing on navigation performance of the glider under different working modes was analyzed,and the program of wing configuration was determined for two typical working modes.Empirical formula method and curve fitting were used to complete the analysis of the sensitivity of the glider's flight performance to the angles of the two driving motors,providing a reference for the smooth realization of wing configuration.(4)The controllable wing mechanism was processed and assembled.Software and hardware were designed.The unit experiments of controllable wing mechanism were carried out to verify its performance and the variable wing configuration.This can make foundation for subsequent machine test.