Research On Dynamics Modelling And Motion Control Of Deep Sea Rover ROV

The deep sea exploration relies on underwater vehicle technology.With the development of technology and equipments,human beings have the ability to explore more in the deep sea.Under the current development trend,the new requirements are put forward for underwater vehicles,which can adapt to the complex seafloor conditions,high efficiency,long-term,fine operation and so on.However,the traditional underwater vehicles are difficult to meet these requirements.Therefore,the small,flexible and low-cost benthic small-scale crawler vehicles have been received attention and development,which provide the new equipments and technical supports for deep sea exploration.The research content of this thesis is from "Research on the Rover ROV Technology",which is the second topic of "Research on Deep Sea Multi-site Lander and Rover ROV System" of the National Key Research and Development Project.The Rover ROV is a 3000-meter deep sea crawler vehicle,adopts the track driving system,improves adaptability and obstacle-climbing ability by the swing arm.It is mounted on the Muti-site Lander and can worked finely on regional seafloor.Based on the crawler system of the Rover ROV,this thesis studies the working mechanism and obstacle-surmounting ability of track-swing-arm module,and develops an efficient and stable motion control system according to the characteristics of the deep sea environment and the operational requirements.The following are main research contents of this thesis:(1)According to characteristics of Rover ROV,motion mechanism of swing arm is studied,relationship of length and angle of swing arm is found,and design parameters of compensation cam is solved.Based on the pressure-sinkage theory,motion of track and swing arm in the soft soil of seafloor is studied,which provided a theoretical basis for simulation and experiment.(2)The motion control of vehicle's obstacle-surmounting is studied,and the key obstacle-surmounting strategies of big and small steps are formulated.Postures and conditions of Rover Rov during obstacle-surmounting process are analyzed.Considering the influence of water resistance,processes of obstacle-surmounting in different situations are studied.(3)Based on RecurDyn,a multi-body dynamics simulation software,the simulation model of crawling and obstacle-surmounting are built.The correctness of design parameters of swing arm is verified by simulation.Crawling in different situations and obstaclesurmounting of different steps are simulated in RecurDyn.(4)The motion control platform of crawler system is developed.Hardware circuit and software program of Rover ROV are designed.Throughing the pressure experiment and underwater experiment,performance of the vehicle is tested.The underwater combined task is successful in the simulated real application scenario,and proves the feasibility of control system design and the rationality of theoretical analysis.