Design And Simulation Of Search And Rescue Robot With Transformable Wheel

The search and rescue robot with transformable wheel is an important research content in the field of mobile robot.It can well adapt to the complex terrain environment in the working area of search and rescue robot,so as to replace the rescuers to enter the dangerous and narrow area to search for the injured,disaster detection and other tasks,and has a broad application prospect.In this paper,based on the actual needs of search and rescue robots and the development trend of moving platform,a search and rescue robot with transformable wheel is designed,which combines the high mobility of wheeled moving platform with the high terrain adaptive ability of arc-legged moving platform.The main research contents include structure design,parameter optimization,kinematics simulation and finite element analysis.The main research results obtained in this paper are as follows:(1)The number of spokes is determined to be 3 by studying the relationship between the number of spokes and the kinematics performance(driving force,driving moment,obstacle height,centroid fluctuation)in the arc-leg mode.According to the working requirements of search and rescue robots,a transformable wheel that can freely transform between wheel structure and leg structure is designed based on the motion mechanism of creatures with excellent motion ability in nature.Then,using the method of image geometry and taking the step as the target obstacle,the inner law of the structural parameters of the transformable wheel is studied,and the maximum expansion radius(which is twice of the radius of the wheel structure)is obtained on the premise that the radius of the wheel structure remains unchanged.According to the characteristics of the transformable wheel structure,an electromagnetic clutch as the main body of the motion mode transformation structure is designed.By controlling the relative motion state of the external spokes and the internal spokes,the purpose of controlling the wheel free switching structure is achieved.Finally,based on the requirements of the overall design,the overall design of the search and rescue robot with transformable wheel is completed.The designed moving platform can not only move at high speed in wheel mode on flat ground,but also pass through rough area quickly in arc leg mode,which has high theoretical significance and practical application value.(2)The wheel legs are grouped according to the different motion states of the four wheels.The center of gravity projection method is used to analyze the stability of the search and rescue robot with transformable wheel on flat ground,slope and side slope.Then,the kinematics model of the search and rescue robot with transformable wheel is established to analyze the obstacle crossing process of the robot,and finally the maximum slope and obstacle crossing height that the robot can stabilize.(3)The search and rescue robot with transformable wheel simulation model is built in Solid Works software,and the target obstacle model is built according to the characteristics of the working environment of the search and rescue robot.The model is imported into ADAMS software to verify the feasibility of the motion mode transformation mechanism design.At the same time,the results also show that the designed search and rescue robot has good obstacle surmounting ability,adaptive ability of complex terrain and steering performance.In addition,through the search and rescue robot under different phase difference(0 °,15 °,30 °,45 °,60 °)movement performance simulation,the results show that when the phase difference of 0 °,centroid width of fluctuation in the biggest(75 mm)and the slowest,with the increasing of phase difference,centroid fluctuation amplitude decreases but accelerated gradually,when the phase difference is 60 °,centroid fluctuation(about 25 mm)minimum but speed is the largest.(4)Firstly,the simplified model of reconfigurable wheels is drawn in Solid Works software and imported into ABAQUS software.The transformable wheels are lightweight designed by changing the wheel material and partial material reduction.The final results show that when the material of the reconfigurable wheel is steel,it can meet the strength requirement whether or not the wheel is treated with material reduction.If the material is aluminium alloy,it cannot meet the strength requirement well.