Design And Analysis Of A Novel Linkage-Coupled Wheel-legged Mobile Robot

Wheel-legged mobile robots are a new branch of mobile robots.They not only retain the fast and efficient walking performance of wheeled robots on flat ground,but also combine the obstacle crossing ability of legged robots on unknown complex terrain.Based on researching and summarizing the existing research results at home and abroad,this paper introduces the parallelogram mechanism into the design of the wheg,and puts forward a design scheme of a novel linkage-coupled wheel-legged mobile robot.Moreover,this robot is studied in some respects such as structural design,gait planning,software simulation,prototype production and experiments.The overall structural design of the robot is completed,especially the design and kinematics analysis of the twin whegs.The linkage-coupled whegs is one of the main innovations of this paper.Benefit from the movement characteristics of parallelogram mechanism,the purpose of moving the two single whegs with exactly the same movement by only a motor is achieved without increasing the total wheg number.Auxiliary structure is designed to solve the motion uncertainty of the parallelogram mechanism in the collinear position.Support states of the rim and the ground and the movement rule of the geometric center of wheg are analyzed.Based on the characteristics of the twin whegs,the gait planning of the robot,including climbing gait,diagonal gait and rolling gait,are completed by drawing some concepts and methods in the gait planning of legged robots.The principle and feasibility of these three gaits are explained,and they are analyzed and compared from the aspects of static stability margin,fluctuation of the center of gravity and average walking speed.Their advantages and disadvantages for each gait are found,and their appropriate application scenarios are studied.In the ADAMS software,the simulation model of the robot is established.And compared with the traditional quadruped wheel-legged mobile robot,these three gaits are simulated on the flat ground and ditch ground respectively.The simulation results are in good agreement with the results of the theoretical analysis,and the improved performance of the twin whegs and the feasibility and superiority of these three gaits are also improved to some extent.The design and manufacture of the prototype are completed.To verify these three gaits,a series of experiments on this prototype are carried out,and the experimental platforms are flat ground,cobblestones and stairs.The feasibility and practicability of structural design and gait planning are further validated.Some problems are found,and they provide some reference and evidence for the improvement work.