Li Yueming

S plane control based on parameters optimization with simulated annealing for underwater vehicle

Nonlinearity of underwater vehicles(UVs) and complexity of working environments make the precise control of AUVs difficult for some of the intelligent operations. Based on the analysis of fuzzy control and combined with the form of PID control, S plane control is a simple and effective method, but parameters must be manually set for its controller. Improved simulated annealing algorithm is introduced to S plane control method to optimize the controllers parameters automatically. The feasibility and advantages of the algorithm has been demonstrated by simulation results.

A Method of Instruction Understanding for AUV Control Layer Based on Attention Mechanism

In order to maintain an appropriate relationship between the planning layer and the control layer of autonomous underwater vehicle(AUV),with Itti visual attention model considered as a reference,a planning instruction understanding (PIU) model based on attention mechanism is presented,and the processes of PIU and the secondary planning are established. The attention focus of planning instruction is obtained using fuzzy reasoning for analyzing the feature and significance of instruction element.Furthermore,the secondary planning is implemented adopting attention focus,which can ensure a higher priority execution of the state concerned by the planning layer.The simulation results demonstrate that the proposed PIU process can not only realize the acquisition of the instruction intention of planning layer,and the planning instruction can be executed more effectively,but also the motion control effect is heightened and the intelligence level of control layer is improved.

A method for weakening the chattering of sliding mode controller

On the basis of approach-rate method, an assisted sliding surface was set, sliding region was defined, and equivalent control in sliding region was given. Sliding region was used to make the system get into sliding region in limited time and oscillate at low frequency near sliding region to take the place of high frequency oscillation at sliding region of traditional sliding mode controller. The chattering can be weakened in such way. The stability of system at sliding region was analyzed with stability theory. The advantage of sliding region method was introduced, compared with high-gain method and approach-rate method. Finally, the simulation experiments were done on the ldquoXXrdquo autonomous underwater vehicle to validate this method.