Structure Design And Reconstruction Kinematics Research Of Unmanned Metamorphic Vehicle Under Parking

Combined with the high speed and high efficiency of the wheel mechanism and the mobility flexibility of the leg mechanism,this paper proposes an unmanned metamorphic vehicle which can be driverless and can naturally switch between wheel driving and foot walking.The vehicle has the characteristics of fast global cell transformation when it switches between vehicle state and humanoid state.In order to solve the problems of impact and collapse during the rapid global reconstruction,the kinematic model of the reconstruction is established based on the structural design and reconstruction planning.Through the simulation of kinematic model,we can master the reconstructed kinematic behavior and design the smoothness and stability of its motion.The specific research contents are as follows:Firstly,the car body,lifting mechanism,leg mechanism and modification center device are designed and analyzed,and based on the folding arrangement of leg mechanism in the car body,two kinds of arrangement schemes of leg mechanism are proposed,and based on the motion independence of the lifting mechanism and the leg mechanism,two reconstruction modes are proposed when the car parks,and the optimum design of the configuration and size of key components of the car is carried out.Secondly,the kinematics analysis is carried out according to the characteristics of the parking forward reconstruction motion under the two leg mechanism arrangements of the car.Based on the screw theory and D-H parameter method,the forward kinematics model of the parking reconstruction process of the vehicle is established.According to the requirements of maintaining the level of front frame and rear frame during the reconstruction process,the horizontal lifting motion is designed,and the motion characteristics of the system are analyzed based on the established kinematics model.Then,based on the consideration of the smoothness of the reconstruction process,the trajectory planning of each joint is carried out.Based on the consideration of the stability of the reconstruction process,the ZMP model of the parking reconstruction process of the vehicle is established,and the stability of the two reconstruction modes under the two leg mechanism arrangement schemes of the car is compared and analyzed.The coupling reconstruction mode under one scheme is selected as the optimal coordination.Based on the influence of the foot landing position on the stability of the reconstruction process,the foot landing position is determined optimize the design.Finally,the virtual prototype simulation model of unmanned metamorphic vehicle is established by Solid Works and MATLAB,and based on this model,the parking reconstruction kinematics simulation of the car is carried out,which verifies the rationality and correctness of the established kinematics model.