Research On Motion Control Method Of Amphibious Crab-Like Multi-Legged Robot

In today's world,science and technology are developing rapidly,and the demand for marine resource development is increasing.For many tasks in the fields of marine facility inspection,marine resource exploration and data collection,offshore reconnaissance,defense and rescue in complex environments such as offshore seabeds and shallows,it is necessary to develop a multi-purpose robot with amphibious movement capabilities.Based on the National Natural Science Foundation of China project "New Concept Biomimetic Amphibious Robot Crab Key Technology Research",this paper mainly studies the motion control method of the amphibious crab-like multi-legged robot under the multi-leg crawling motion mode,and researches the virtual prototype motion simulation technology.First,based on the kinematics of the amphibious crab-like multi-legged robot,the kinematics of the walking foot of the robot is studied and analyzed.Use D-H method and algebra method to calculate the forward and inverse solution of robot walking foot kinematics,and establish a walking foot simulation model through MATLAB to verify the feasibility of the kinematic analysis results;The Monte Carlo method is used to simulate the walking foot workspace,which provides a theoretical basis for the gait planning and walking foot trajectory planning of the amphibious crab-like multi-leg robot.Secondly,study the gait planning and trajectory planning of the amphibious crab-like multi-leg robot.Analyze the gait parameters to determine that its walking gait is "triangular gait",and plan the straight and turning gait of the amphibious crab-like multi-legged robot by phase analysis and graphical gait;Aiming at the problem of ground impact caused by the different degrees of softness and hardness of the ground when the robot is moving on the seabed and tidal flats,an improved compound cycloid method is used to plan the motion trajectory of the foot end of the walking foot,and a weak impact swing phase and support phase foot end motion are designed The trajectory and simulation analysis verify that the trajectory meets the requirement of zero speed and acceleration when the amphibious crab-like multi-legged robot changes its swing phase and support phase during walking.Thirdly,the problem of tracking control algorithm for walking foot trajectory of the amphibious crab-like multi-legged robot is studied.Among them,in view of the uncertainty of ocean current interference and the uncertainty of motion model parameters during the movement of the robot on the seafloor,the problem of the uncertainty of the motion model parameters is unified as a lumped uncertainty,and an adaptive finite time interference observer is designed;At the same time,in order to improve the tracking control accuracy and response speed of the walking foot trajectory of the amphibious crab-like multi-legged robot during walking,combined with a global fast terminal sliding mode surface,a global fast terminal based on an adaptive finite time interference observer is proposed.Sliding mode control method;In addition,in view of the input saturation problem in the actual control system,an auxiliary system is designed,and a global fast terminal sliding mode control strategy based on an adaptive finite-time disturbance observer under input saturation is proposed;and the MATLAB simulation experiment verifies this article The feasibility and superiority of the proposed control strategy.Finally,a virtual prototype simulation experiment platform based on Simscape Multibody is developed.The simulation verification of the gait,foot end trajectory and walking foot trajectory tracking control algorithm proposed in this paper verifies the feasibility of the research content in this paper,and provides a powerful reference value for the development of a physical prototype experimental platform.