The Research On A Technology Of Dynamic Positioning To Line For AUV Docking Recovery

With the technology development of AUV(Autonomous Underwater Vehicle),the model of ocean workstation carrying small underwater robots is focused on because of many advantages.This model requires that underwater robots can be deployed and recovered in the water. There is a docking compartment on the back of ocean workstation which is for carrying AUV.When ocean workstation navigates,AUV is in docking compartment,so AUV won't affect ocean workstation.When ocean workstation arrived at destination,AUV is deployed.When AUV completed it's task,it will come back to docking compartment.And the process is very difficult.When AUV docking,it's environment changing from an infinitely broad waters to a restricted waters,in this process,hydrodynamic forces will perform complicatedly due to the hydrodynamic interactions,and this will have an adverse impact on the recovery,So hydrodynamic interference becomes an unavoidable problem which needs to be solved.Many theories and numerical calculations about hydrodynamic interactions are presented currently.In this paper,we use the software fluent to solve the hydrodynamic interference problem,the results show that the main hydrodynamic interactions including heave force and pitching moment.Finally,we proposed the formula for hydrodynamic interference.Base on the research of hydrodynamic interference,we establish AUV's movement mathematical model which is under the hydrodynamic interference.The shape of AUV and docking compartment is rectangle,ordinary single point of positioning control method can not be used to slove this problem,so we use the bow and stern double reference point Positioning control method(dynamic positioning to line method) in this paper.Finally,fuzzy self-tuning PID control method is used in digital simulation.