Research On Dynamic Positioning Of Remote Controlled Underwater Vehicle Based On Multi-Motor Cooperative Propulsion

The ocean occupies more than 70% of the earth’s surface,and it is rich in a large amount of minerals,energy and biological resources.Today,when resources are increasingly scarce,countries are vigorously developing marine resources.As a common equipment for underwater observation,operation and exploration,ROV(Remote Operated Vehicle)plays an important role in the ocean development process.Based on the self-developed operational ROV,this thesis conducts research on multi-motor control strategy,permanent magnet synchronous motor control method,ROV dynamic positioning control and underwater robot experimental system development.First of all,this thesis analyzes the latest research status and trends at home and abroad on operational ROV,multi-motor control strategy,permanent magnet synchronous motor control method,and dynamic positioning of underwater robots’ design.Secondly,a new method of multi-motor cooperative dynamic positioning control for operational remote-controlled underwater robots was studied.In terms of multi-motor control strategy,this thesis proposes a control strategy combining virtual main axis and deviation coupling,which makes the advantages of the two control strategies complement each other,so as to improve the speed and accuracy of multi-motor cooperative propulsion of remotecontrolled underwater robots;In terms of the control method of a permanent magnet synchronous motor,in view of the problem that the stability and dynamic performance of the finite set model predictive current control are degraded when the parameters are mismatched,this thesis proposes a model predictive current control method based on the fuzzy PID type cost function;In terms of dynamic positioning,this thesis establishes a mathematical model for the operational ROV and simplifies it into a 4-degree-of-freedom kinematics and dynamics model.On the basis of this model,a novel dynamic positioning controller based on backstepping is designed.In order to verify the multi-motor control strategy proposed in this thesis,the permanent magnet synchronous motor control method and the designed dynamic positioning controller,this thesis builds a simulation model in Simulink,and the simulation results show that the multi-motor synchronous control strategy combined with virtual spindle and deviation coupling,Model Predictive Current Control Method Based on Fuzzy-PID Type Cost Function and Effectiveness of Backstepping Based Dynamic Positioning Controller.Then,participated in the development of the experimental system of the operational ROV,mainly including the water surface monitoring system and the master-slave manipulator system.The water surface monitoring system includes ROV motion monitoring system,power supply system and sonar system.Among them,the software and hardware of the information acquisition circuit board of the water surface monitoring platform and the monitoring software of the host computer based on Qt are mainly designed.The master-slave manipulator system includes hydraulic system,manipulator system and power supply system,among which the software and hardware of the information acquisition circuit of the master manipulator,the software and hardware of the control circuit of the slave manipulator and the software and hardware of the frequency converter control circuit are mainly designed.Finally,the experiment and result analysis of the operational ROV are carried out.The experiment includes the actual test of the circuit board designed in this thesis and the monitoring software of the host computer based on Qt,the master-slave manipulator joint debugging,the permanent magnet synchronous motor model predictive current control experiment,the multi-motor collaborative experiment;and the lake after the overall assembly of the operational ROV The test experiment,including the fixed navigation and fixed depth experiments of dynamic positioning,the final experimental results show that the operational ROV designed and manufactured in this thesis meets the design requirements.