Study On The Mobile Strategy Of Reconfigurable Snake Robot In A Multiform Environment

Snake robots have shown high development potential and application value in field reconnaissance,disaster emergency search and other scenarios due to their high degree of freedom redundancy configuration and high environment-adaptive motion mode.Generally speaking,the more joints a snake robot has,the more types of gait configurations it can achieve and the more adaptable it is to the environment.The more snake robots involved in the task,the less time it takes to explore the surrounding environment,and the more efficient the exploration is.In order to consider both mobility and exploration efficiency,the concept of reconfigurable snake robot is introduced in this thesis: the snake robot is composed of several independent working sub-robots,which can separate and reconstruct the sub-robots while meeting the mobile and exploration requirements,so as to ensure the efficient completion of investigation and search tasks.The research content of this thesis is expanded from the following three aspects:(1)Research on snake robot control method based on main characteristic curve and mobility capability.To achieve reconnaissance and search in a diverse environment,it is necessary to study the gait motion control methods of snake robots.Firstly,the relationship between orthogonal snake robot and backbone curve is studied,and the mapping relationship between gait configuration and joint angle of the robot is obtained.Secondly,the common characteristics between asynchronous configuration are summarized.By extracting the periodic curvature and deflection characteristics of backbone curve,a snake robot gait configuration expression mode based on the main characteristic curve method is proposed.Based on this method,common gaits of various snake robots are realized by parameter degradation,and a sidewinding gait approximating elliptical helix is designed.Finally,based on the motion capability of the snake robot in different environments,a mobile gait library is built to prepare for the design of mobile strategies.(2)Research on docking method of reconfigurable snake robot.Firstly,aiming at the problem that there is no fixed reference coordinate in the docking process of the reconfigurable snake robot,the initial configuration of the docking is designed as follows: winding some joints close to the tail to form a stable base in the docking process,remaining joints form upper parts as the docking actuator;Secondly,by modeling the forward and reverse kinematics of the snake robot,the mapping relationship between the joint space and the operating space of the robot is obtained.Finally,based on Goal bias RRT algorithm and quintic polynomial interpolation method,trajectory planning of reconfigurable snake robot from initial state to target state is realized.(3)Research on snake robot mobile strategy in multi-morphology environment.First,the map to be explored is divided into several morphological areas according to the environmental characteristics applicable to the gait movement of the snake robot,and the multi-gait movement cost fusion between target nodes is realized to obtain the optimal cost between any two nodes.Secondly,the genetic algorithm is used to plan the moving path between target nodes and obtain the minimum moving cost path of snake robot on the map containing various morphological areas.Finally,when confronted with tasks that cannot be accomplished by a single robot,the docking reconstruction between the robots is carried out to obtain a snake robot with stronger motion ability,thus completing the entire map search and all target reconnaissance.(4)Snake robot motion experiment.The snake robot experimental system is developed to verify the research content of this thesis.The experimental results and tests show that the proposed main characteristic curve method can provide theoretical support for gait generation of snake robot,and the docking reconstruction method designed lays a foundation for Strategy Research of snake robot to perform complex tasks in dangerous and uncertain environments.There are 69 figures,12 tables and 84 references in this thesis.