Theoretical And Experimental Study On Compliant Leg Of Amphibious Robot

Over years,researchers focus much attention on robotics,which leads to more and more work on structures,controls and algorithms of robotics.Ampibious robots have incredible adapatability and wide applications.However,diverse environments cause great challenge to design of the propulsion mechanism.There is still no effecient slolutions to the this proplem until now.In this research,a novel flipper like propulsion structure that is totally soft is proposed.The idea originates from existing work and nature animals.Such flipper-legs are fabricated by polyuerathan with a long and straight cuboid shape.The propulsion mechanics are expored and relevant experiments are carried out.The posture and deformation are not linear to the exerted load,which inceases the complexity of modeling,conputation and controls.It's necessary to induce the mechanic model of soft legs.We realize that by using pseudo rigid body model to predicting the large deformation of soft legs in low computation cost.Then the three-spring model is chosen to simulate the forward speed,fluctuation and energy efficiency of flipper-legs.Based on some simple and principle assumptions,six property variables are indepent and complete to determine a PRB-3R model.However,for a certain flipper-leg,these six variables are not unique.They are change by the exerted loads.We obtained the best length of four rigid bars and three stiffness of springs through euler-bernulli beam theory and chain transformation of the induced models' motion.Besides,the performance of flipper-legs in single-leg platform and four-leg platform is primarily explored.The single-leg platform allows us to change and control the terrain convenienty.There are some disadvantages in single-leg platform,so a four-leg platform is assemblied to make the experiment much more similar to the actual locomotion.These two platforms can not produce under-water environment,for which we design an amphibious robot with six flipper-legs.The proper gaits are designed for diverse environments.In a series of experiments,we got velocity,torques,efficiency and some other variables from videos and recording data.Based on various of data,the performance of the amphibious robot and the role that the flipper-legs play are evaluated from multiple degrees.The flipper-legs help the amphibious robot finish all the experiments and the feasibility is proved,which means a strong potential application of such legs.