| Amphibious robot is often used in various special working situations because of its good trafficability and the ability to connect the amphibious environment effectively.However,the existing amphibious robots have some problems,such as poor adaptability to amphibious environment,lack of mobility and instability of underwater motion.Therefore,this thesis will study the structure design and underwater motion control of amphibious robot.Firstly,the amphibious robot with wheel-tilting thruster is designed by combining the land driving wheel and water jet thruster.The amphibious motion principle of the amphibious robot is explained,and the validity and rationality of the composite propulsion structure are verified by fluid simulation.Secondly,aiming at the strong coupling and nonlinear problems caused by thruster tilting in underwater motion,a control strategy of separating thrust and tilt angle is proposed to keep the attitude and heading of the amphibious robot stable.Then,based on the active disturbance rejection control principle and model free adaptive algorithm,the attitude stability controller and the course keeping controller are designed to adjust the thrust and the thruster tilt angle,and the feasibility of the attitude and course controller is verified by ADAMS/Matlab simulation platform.Finally,the prototype of the hybrid amphibious robot is developed and tested,the upper computer software of the amphibious robot prototype is designed,the hardware system of the prototype is built,and the corresponding control experiments are carried out.The experimental results show that the hybrid amphibious robot can achieve the desired movement,and the designed controller has good control effect. |
