The Optimization Of Commercial Vehicle Air Brake System Based On Onthogonal Experiment

The brake system is one of the most critical components in ensuring the driving safety.The air brake system differs from a hydraulic brake system in many ways.One of the most important difference is that pressed air consumes much more time to travel through the pipes compared with the hydraulic oil.Since most commercial vehicles are equipped with air brake system,it is necessary to construct a pneumatic model of the brake system for analyzing and improving its dynamic performance.The main purpose of this research is to investigate the optimal parameter set of pipeline diameter of an air brake system in order to improve brake efficiency using orthogonal experiment method.To achieve this purpose,this paper presents the development and validation of a computer-aided analytical dynamic model of a pneumatic brake system in commercial vehicles within the multi-domain physical modeling software-AMESim based on the logic structure.The transient performance of the single component model was validated by pneumatic bench test.Then an experimental test bench was set up by connecting each component with the nylon pipelines based on the pipeline layout in a real 4X2 commercial vehicle.The experimental data of the transient pressure was measured to verify the simulation accuracy and the positive results of the validation show a potential for investigating the most suitable parameter configuration of the pipeline diameter based on the computer-aided analytical dynamic models.Sensitivity studies are then performed utilizing the orthogonal array sampling method to determine the pipes which exert great effect on the performance of the brake system.In order to save computation expense,the RSM technique was applied to approximate the optimal objectives.Then a new optimization model using NSGA-II multi-objective algorithm(MOEA)was proposed and a set of non-dominated solutions were therefore obtained.With specified assessments,feasible solutions could therefore be selected from the entire field of the Pareto optimal solutions.The numerical result shows that the performance of the brake system has been elevated much after the optimization.