Design Of Amphibious Hexapod Robot Based On Deformable Leg

The working mode of the traditional mobile robot in a single spatial dimension,the highly unstructured terrain of the amphibious environment and the geological features of insufficient effective support force have made it difficult for mobile robots to operate in an amphibious environment.At present,a lot of researches have been carried out on the research of amphibious robots at home and abroad,and quite satisfactory results have been achieved,but there are still many problems in this aspect,such as: it is difficult to guarantee efficient and stable mobile performance and strong environmental adaptation at the same time.In view of the problems exposed by amphibious robots,this paper comprehensively studies and analyzes the propulsion efficiency,advantages and disadvantages of existing propulsion devices,and combines theoretical methods such as mechanism and bionics with advanced tools such as CAD and CAE to comprehensively consider amphibious robots.With the requirements of high speed,large load and long battery life,a propulsion device that can be controlled deformation and meets performance requirements and can be applied to both land and water is proposed.Based on the propulsion device,the first generation prototype of the amphibious hexapod robot is designed and built.The main research contents of this paper are as follows:(1)Through the in-depth comparison and analysis of the applicable occasions,advantages and disadvantages,and propulsion performance of the existing common land propulsion mechanisms and underwater propulsion mechanisms,combined with the application scenarios and the feasibility of institutional integration,a deformable leg based on the slider type is proposed.The design scheme realizes the purpose of bending or straightening state of the deformable leg by changing the position of the slider relative to the track,and on the basis of the proposed scheme,the corresponding deformation performance verification experiment is carried out,and based on the experimental results,the driving is determined.The transmission scheme and hardware selection of the mechanism realize the physical assembly of the deformable legs.(2)Through the kinematics analysis of the length of the support arm during the standing process of the deformable leg,combined with the plane geometry theorem and the matlab solution,the relationship between the maximum ground clearance height of the robot(the maximum support arm)and the motor rotation angle is obtained;The kinematics analysis of the velocity of the grounding point gives the relationship between the velocity components and the acceleration components in the horizontal and vertical directions and the motor rotation angle;on the basis of the known relationship between the maximum support arm and the acceleration,the dynamic analysis of the deformed leg is performed.The change trend of the maximum output torque of the motor during the standing process is obtained.The inversion method is used to solve the speed expression of the robot when it moves in three-step gait,and the deformation leg is optimized according to the kinematics and geometric constraints.Combined with the basic formula of underwater dynamics and Newton's second law,the underwater dynamics analysis of the robot is carried out,and the underwater dynamic model of the robot is established and solved to provide an optimized direction for the adaptability of the deformed leg to the underwater environment.(3)Plan the layout,hardware selection and 3D modeling of the robot,ADAMS-based land deformation performance simulation,machine motion simulation,and contradistinction simulation with fixed legs are performed,and Xflow-based underwater simulation of ascent,sink,forward,and rest states are carried out.physical prototype assembling and performance verification experiments are carried out.