Research On Smoothness And Stability Of Parking Coupling Reconfiguration Of Unmanned Metamorphic Vehicle

A mechanism characterized by a change in the number of effective components and a change in degrees of freedom during the movement of the mechanism is defined as a metamorphic mechanism.In this paper,based on the research theory of the metamorphic mechanism,the foot-type mobile mechanism and the wheeled mobile mechanism are combined to design an unmanned vehicle that can quickly reconstruct the metamorphic cell globally.Because of its high driving performance on structural pavement and high passability on unstructured pavement,unmanned metamorphic vehicles can be widely used in special use environments such as interstellar detection,anti-terrorism and riot control,and earthquake relief to complete specific instruction tasks.This paper mainly studies the stability and smoothness of the coupled reconstruction process based on the kinematics and dynamics of unmanned metamorphic vehicles.According to the structural characteristics of the unmanned metamorphic vehicles,and based on the theory of homogeneous coordinate transformation,the kinematics model of the parking coupling reconstruction process is established.Then,according to the requirements of coupling reconstruction smoothness,the rotation law of each joint is designed.Taking the ZMP(zero moment point)as the stability criterion,the stability of the unmanned metamorphic vehicle parking coupling reconstruction process is analyzed.On the basis of kinematics,through Lagrangian dynamics,a dynamic model of the parking reconfiguration process of unmanned metamorphic vehicles is established.The driving torque calculation expression of each joint is derived,and the applied torque of the joint is simulated and analyzed by the given joint motion law.In order to ensure the smoothness and stability of the coupled reconstruction,the dynamic control model of the unmanned metamorphic vehicle coupled reconstruction is used as the control object,and a control strategy for the smoothness and stability of the unmanned cellular vehicle coupled reconstruction is proposed.In order to ensure the smoothness of the coupling reconstruction,a sliding mode controller based on particle swarm optimization is designed for the ankle,knee,hip,lifting joint and putter.The simulation results show that the sliding mode controller based on particle swarmoptimization can well realize the trajectory tracking of the position and speed of each joint.In order to ensure the stability of the coupling reconstruction,a fuzzy PID controller is designed for the variable centroid mechanism,and a comprehensive simulation of the stability control strategy for the coupling reconstruction of the unmanned variable cell vehicle in Matlab / Simulink is simulated.The simulation results show that the control strategy is feasible,and it can ensure the smoothness and stability of the coupling reconstruction of the unmanned metamorphic vehicle.