| The underwater glider has the advantages of low cost,low noise and long endurance which is thus applied in various ocean explorations.Nowadays,the demand for high-quality ocean exploration puts more stringent requirements for the performance of underwater gliders.However,the driven buoyancy will be affected by the change of ocean environment due to the vastly spatial moving.As a result,its performance is affected in terms of motion stability,energy efficiency and endurance.This thesis proposes a novel hybrid passive buoyancy compensation system to compensate for the buoyancy variation of underwater gliders and accomplishes the scheme design,parameter optimization,effect evaluation and experimental verification.The specific research results are as follows:(1)This thesis proposes a hybrid passive buoyancy compensation system,integrating three standalone buoyancy compensation devices of spring accumulator,inflatable accumulator,and silicon oil bladder.The mathematical compensation model of this system is established and an effective genetic algorithm is adopted to optimize the design parameters.The case study of a Petrel-L underwater glider shows that the optimal system can significantly improve the buoyancy compensation.Compared to the underwater gliders without compensation and with only a single compensation device,the buoyancy variation of the underwater gliders with the hybrid buoyancy compensation system respectively decreases 94.53% and 67.78%,respectively.(2)The motion stability,energy efficiency and endurance of the underwater glider with the hybrid passive buoyancy compensation system are calculated by the simulation models and compared with those of other underwater gliders.Results indicate that the underwater glider with the hybrid passive buoyancy compensation system has a superior performance in motion stability,but its endurance and energy efficiency are affected by the hotel loads of underwater glider and the mass brought by the hybrid passive buoyancy compensation system.(3)The passive buoyancy compensation devices are designed,manufactured and tested according to the optimized feature parameters of the hybrid passive buoyancy compensation system.Then,the compensation value of different buoyancy compensation devices under working pressure are obtained through the corresponding test.The measured value is in accordance with the theoretical value as the error is within a reasonable range,which verifies the effectiveness of the hybrid passive buoyancy compensation system. |
