Research On The Key Technologies Of The Underwater Spherical Robot

With the development of science and technology,human beings have achieved great success in underwater robots and have obtained more advanced ways of acquiring resources.But in the face of the unknown and complicated marine environment,mankind must now rely on the underwater vehicle.Therefore,the underwater robot has become an important tool for mankind to explore,exploit and utilize the marine resources.First of all,this paper proposes a novel Spherical Underwater Robot(SUR-III)with four vectored water-jet thrusters,in order to overcome the shortcomings of the existing propeller propulsion methods,such as large noise,poor concealment and large impact on the ecological environment.As the propulsion system,the more compact structure helps to improve the overall underwater spherical robot's operating speed and energy efficiency.This is one of the innovations in this paper.The working principle of the vectored water-jet propulsion system is that each water-jet thruster consists of two servomotors.The two servo-electrical cooperation can flexibly control the movement direction of robot.Secondly,in the study of the distribution and thrust prediction of the new propulsion system,this paper uses four sets of vectored water-jet thruster.First,a more reasonable water-jet propulsion system is studied in the propulsion system.The allocation and thrust forecast are further discussed,which includes the layout of the overall structure and the thrust derivation.There are mainly some common thrust forecasting methods,and then we analyze and experimentally measure the principle of the water-jet thruster.And a single water-jet thruster has been improved and innovated and related fluid mechanics simulation tests are conducted.At the same time,the model established in this chapter based on the water jet propulsion system is also the basis for the kinematics and hydrodynamics analysis for the new underwater spherical robot.Thirdly,the motion control algorithm is another key technology to realize the stable motion of the underwater spherical robot.Firstly,the general kinematics model of the underwater robot is obtained,and the structural characteristics of the underwater spherical robot developed in this paper are applied to simplify the kinematic model.Then the PID algorithm and the fuzzy sliding mode algorithm are studied respectively,and we carry out the relevant simulation research and comparison on MATLAB.On this basis,combining the advantages of these two algorithms and the characteristics of the master-slave control structure,a more intelligent and simple motion control scheme is proposed.Finally,underwater experiments of the new underwater spherical robot are carried out based on the fuzzy control thought and the sensor feedback information,translational movement,rotation and lifting movements are also carried out,as well as the underwater multidepth motion experiments,this underwater experiment verifies the reliability and effectiveness of the developed underwater spherical robot.