The mobile loading arm(MLA)system is one of the most important mechanical equipments in the petrochemical industry consisting of rigid pipelines and rotating elbows.This paper researches the problems of dynamical mode...The mobile loading arm(MLA)system is one of the most important mechanical equipments in the petrochemical industry consisting of rigid pipelines and rotating elbows.This paper researches the problems of dynamical modelling and tracking control.At first,an MLA dynamic model is built by using Euler-Lagrange function.And then,an adaptive third-order fixed time sliding mode(FDTSM)tracking controller with chattering free is represented,which enables the MLA system to dock with the vehicle tank mouth.In this paper,a new double-layer third-order fixed time sliding mode controller is first proposed to address the tracking problem in model-based MLA systems with known parameters.Moreover,considering the presence of modeling uncertainty and external disturbances,a nerual network adaptive FDTSM controller is designed to ensure that the close-loop system state tracking error converges to a bounded region around zero within a fixed time.Further,the stability of the close-loop system is proven by using the Lyapunov stability theorem.Simulation results illustrate the validaty of the controller.展开更多
This study establishes a runway model based on the elastic layered theory and simulates the taxiing processes of B737-800 and A320 using step loading to analyze the influence of landing gear configurations on pavement...This study establishes a runway model based on the elastic layered theory and simulates the taxiing processes of B737-800 and A320 using step loading to analyze the influence of landing gear configurations on pavement deflection.The results show that subgrade deformation accounts for over 90%of the total deflection,with the peak dynamic displacement occurring beneath the inner wheel imprint.The displacement is primarily governed by the subgrade modulus(its influence diminishes beyond 100 MPa),surface layer thickness,and single-wheel load(both exhibiting linear effects).A multivariate nonlinear regression was performed to derive a calculation formula for the peak vertical dynamic displacement of the subgrade,providing a reference for displacement field research and performance optimization of pavement structures.展开更多
基金supported by the Beijing University of Posts and Telecommunications(BUPT)Excellent Ph.D.Students Foundation under Grant No.CX2020116。
文摘The mobile loading arm(MLA)system is one of the most important mechanical equipments in the petrochemical industry consisting of rigid pipelines and rotating elbows.This paper researches the problems of dynamical modelling and tracking control.At first,an MLA dynamic model is built by using Euler-Lagrange function.And then,an adaptive third-order fixed time sliding mode(FDTSM)tracking controller with chattering free is represented,which enables the MLA system to dock with the vehicle tank mouth.In this paper,a new double-layer third-order fixed time sliding mode controller is first proposed to address the tracking problem in model-based MLA systems with known parameters.Moreover,considering the presence of modeling uncertainty and external disturbances,a nerual network adaptive FDTSM controller is designed to ensure that the close-loop system state tracking error converges to a bounded region around zero within a fixed time.Further,the stability of the close-loop system is proven by using the Lyapunov stability theorem.Simulation results illustrate the validaty of the controller.
文摘This study establishes a runway model based on the elastic layered theory and simulates the taxiing processes of B737-800 and A320 using step loading to analyze the influence of landing gear configurations on pavement deflection.The results show that subgrade deformation accounts for over 90%of the total deflection,with the peak dynamic displacement occurring beneath the inner wheel imprint.The displacement is primarily governed by the subgrade modulus(its influence diminishes beyond 100 MPa),surface layer thickness,and single-wheel load(both exhibiting linear effects).A multivariate nonlinear regression was performed to derive a calculation formula for the peak vertical dynamic displacement of the subgrade,providing a reference for displacement field research and performance optimization of pavement structures.
