| Obtaining information on the location and health status of trapped individuals as soon as possible in post-disaster rescue work is crucial to ensuring the smooth progress of disaster relief and rescue efforts.At present,rescue robots represented by drones and unmanned vehicles have played important roles in rescue scenarios,such as wide-area search,auxiliary transportation,and emergency communication.However,there are still closed spaces with narrow entrances and variable terrain in the post-disaster environment,and corresponding specialized rescue robots are relatively lacking.Biomimetic snake-like robots possess the characteristics of slender biological snake bodies and the ability to move and climb in narrow and unstructured environments.Reconfigurable robots can improve their movement ability and exploration efficiency by changing their own configurations.The combination of snake robot and reconstructed robot has good application prospects in post-disaster search and rescue missions.However,the current research on reconfigurable design and motion control of snake robots is difficult to meet the needs of emergency rescue after disasters.This thesis focuses on the characteristics of post-disaster environments and proposes research on the reconfigurable design and motion control of snake robots.The main focus is on studying the motion gait modeling method of snake robots suitable for postdisaster environments,developing a reconfigurable mechanism that improves exploration efficiency,overcoming the difficulty of continuous crossing motion in complex spatial cylinders,exploring the smooth transition method of gaits in continuously changing terrains,and realizing the motion planning in scene tasks by multi gaits,which provide guidance for the practical application of snake robots in postdisaster environments.The main research contents include:(1)The kinematics models of multiple gaits of snake robot are established.Firstly,the characteristics of post-disaster scenario characteristics and the basic theories of gait control are comprehensively analyzed to determine the joint form and the main motion gaits of snake robot.Then,based on the characteristics of post-disaster scenarios,models of ground motion gait and cylinder climbing gait are studied using the climbing environment as the standard,and explicit velocity expressions for the Rolling series gait are given,while estimation models for other gaits are also provided.At the same time,new climbing gaits have been designed: Crawler derived gaits and C-pedal derived gaits,expanding the available gait configurations for snake robots.Finally,the kinematics model is verified in the simulation.(2)The influence of joint number on gait characteristics is analyzed,and a reconfigurable docking mechanism with electromagnetic mechanical coupling is designed.Firstly,based on the multiple gait models,the relationship between the joint number and gait characteristics is analyzed,leading to the requirement for reconstruction function.Then,taking advantage of the difference in coercive magnetic properties between hard and soft permanent magnet materials,a drive module for the reconfigurable mechanism is designed based on the principle of electric permanent magnet.The drive model is established using the equivalent magnetic circuit method and verified through electromagnetic simulation.Finally,a mechanical locking structure is designed under dimensional constraints,and the docking tolerance range of the reconstructed mechanism is analyzed.(3)A cross gaits generation method for complex spatial cylinders is designed.Inspired by the process of paper curling/unfolding,the problem of 3D gait generation of snake robot is reduced to that of 2D gait generation.Based on the kinematic modeling of the Rolling series of gait,the geometric configuration changes of the robot under the relative positions of the parallel,crossed and staggered cylinders are analyzed respectively,and the efficient and continuous cross gait CHR(Cross Helix Rolling)is proposed.(4)A series of transition methods between gaits are proposed,and a gait transition network for snake robots is constructed.Firstly,a cost function for parameter transition is designed based on the spatial dimensions of the standardized gait configurations,providing guidance for parameter selection during parameterized gait static transition.Secondly,based on the constraints of configuration shape control,a dynamic transition method based on gait backbone is designed,which achieves the transition motion between various ground gaits.Then,by transforming the climbing environment and reconstructing constraints,the transition motion from ground gait to cylindrical gait with phase control is achieved.Finally,a gait transition network of the snake robot is constructed using gait as nodes and the transition motion as edges,achieving a graphical representation of the transitionable relationships between multiple gaits.(5)A multi gait motion planning method in multi feature terrain is studied.Firstly,based on the gait kinematics model and the gait transition network,the gait library of the snake robot is established.Secondly,according to the distribution of special terrain,the eight connected map of nodes is drawn,and then the adjacency matrix based on moving cost is constructed according to the movement ability.Further,a multi gait adjacency matrix is fused with the help of the transitionable relationship between gaits,and then the graph search method is used to develop motion strategies for fused weighted edge node graphs.Finally,in order to improve the path quality in the strategy,the research on local path planning based on kinematics model is carried out.(6)A snake robot experimental system is designed and built for experimental research.Specifically,it includes multi gait performance testing,Rolling series gait model validation,feasibility verification of spatial cylinders crossing gait,and gait transition motion testing.A simulated post-disaster experimental scenario is built to comprehensively verify the planning ability and motion performance of snake robots in post-disaster multi feature terrain.There are 104 figures,21 tables,and 103 references. |
