Design,Modeling And Analysis Of A Hexapod Robot

In recent years,mobile robots are getting more and more attention.Whether it is a wheeled mobile robot represented by Roborock or a leg type represented by Unitree.Which are favored by capital.Wheeled robots are suitable for moving on continuous ground,with high energy utilization,but cannot adapt to complex terrain;legged robots can move on irregular ground and can adapt to complex terrain,but have high energy consumption and low operating efficiency.The wheel-footed robot not only makes use of the high energy utilization characteristics of the rolling motion of the wheel on flat ground,but also introduces the feature of highly adaptable to the environment of legged robot,making it suitable for complex and irregular terrain.Therefore,wheel legged robot will be a trend in the development of mobile robot in the future.This article has made an intensive study of design,modeling and analysis about the hexapod with wheel leg which have non-complete round shape(similar to Rhex),and the main contents are as follows.1.Firstly,design the body mechanical structure of the hexapod with wheel leg,conduct experiment with a variety of leg materials,design the electrical system and write the motion control program to realize movement modes such as forward,backward,acceleration,deceleration,differential turning,and cross turning.2.Carrying out finite element analysis and simulation on the wheel leg of the robot,verifying that the static characteristics,modal characteristics,transient impact response characteristics and resonance characteristics meet the requirements of the working conditions.3.Modeling kinematics of the robot.Firstly,use non-holonomic constraints to perform rigid kinematics modeling,and then perform instantaneous mechanical analysis on a single wheel leg.Through appropriate simplification and the introduction of the Castigliano's Theorem,the changing stiffness equation of wheel leg will be obtain and then putting forward the idea with "virtual auxiliary arc wheel leg" to equivalent actual wheel leg,the elastic kinematics model of the robot can be further established.4.Verify the variable stiffness elastic kinematics model based on nonholonomic constraints.The first is to conduct co-simulation using Adams and Ansys to verify the correctness of our elastic kinematics model.Then,through the real prototype and using the Motion Capture system to capture the real-time position of the robot to verify the validity of the analytical model again.The results show that our theoretical model can reflect the motion state of robot during the touchdown phase very well.Finally,the continuous motion experiment with simulation is conducted to explore the influence of control parameters on the speed and vibration of the hexapod.In this project,we construct a hexapod with wheel leg which have non-complete round shape.This robot can be applied to a variety of terrains.We modeling the kinematics which considering the elastic deformation of wheel legs for this robot.The results show that regardless of whether the hip rotation angle is proportional to time,the second square of time,or the third square of time,the theoretical model in this paper can reflect the real movement of the robot very well.We proposed a more complete modeling method based on Aydin et al.