Research On Control System Of Open Abrasive Belt Grinding Unit For Rail High-Speed Grinding Vehicle

With the continuous increase of railway operation mileage in my country,the demand for rail maintenance is rising rapidly,and the operation time is increasingly tight.More efficient,high-quality and economical rail grinding technology is urgently needed.The open abrasive belt high-speed grinding technology has the advantages of elastic and high-efficiency grinding,not limited by "skylight time",and long continuous grinding mileage,which makes it have obvious advantages in efficiency,grinding quality and economy.However,the coupling effect between the control quantities of the open abrasive belt grinding unit is obvious,and at the same time,due to the disturbance of the rail irregularity and rail disease during the high-speed grinding process,it is difficult to realize the coordinated control of the speed-tension of the abrasive belt and the constant control of the grinding pressure.Therefore,this paper studies the structure and control system design of the open abrasive belt grinding unit for rail high-speed grinding vehicle,the control strategy and performance verification of the grinding unit,etc,to provide theoretical and technical support for promoting the development and application of open abrasive belt grinding technology.First,according to the overall requirements of the grinding unit and the actual grinding requirements,the overall structure and control system scheme of the grinding unit are preliminarily determined,which provides a basis for subsequent modeling analysis and control algorithm design.By analyzing the belt force and tension generation principle and the torque balance equation of each reel,the mathematical model between the belt speed and tension and the control amount of the winding motor voltage and magnetic powder brake is obtained.The structure of the device is analyzed,and the mathematical model of the grinding pressure loading system is established.Secondly,considering the installation of the tension sensor in the actual working condition,it is proposed to use the tension observer for tension feedback,and the tension observation model of each stage is established by analyzing the mathematical model of the winding system.Combined with the mathematical model of the open abrasive belt grinding unit and the complex working conditions faced by the open abrasive belt grinding control technology,it is proposed to use the active disturbance rejection control algorithm and the fuzzy PID control technology to realize the belt speed-tension coordinated control and the constant grinding pressure control respectively.Through the adjustment of the technical parameters of the ADRC,the ADRC controllers for the startstop stage,the decompression application and the normal grinding stage are designed respectively.At the same time,by adjusting the fuzzy PID parameters,the grinding pressure for the decompression and normal polishing stages is designed constant controller.Based on the mathematical model of the grinding unit,a SIMULINK simulation model was established,and the effectiveness of the tension observer,the belt speed-tension coordinated control and the grinding pressure constant control algorithm was preliminarily verified through the simulation model.Finally,based on the above simulation model,the influence of the key parameters of the grinding unit on the control performance was explored,the key components of the grinding unit were selected,and the structure of the grinding unit was designed in detail.On this basis,in order to verify the performance of the measurement and control algorithm in a more realistic situation,according to the properties of the abrasive belt and the structure of the grinding unit,the ADAMS-MATLAB co-simulation model of the virtual prototype of the grinding unit is built.Under different grinding speeds,the co-simulation of each stage of forward and reverse grinding is carried out,and the control performance analysis of grinding unit under different control strategies is carried out,and the designed tension observation algorithm,belt speed-tension force under different working conditions are verified.Accuracy and effectiveness of coordinated control and grinding pressure stabilization control algorithms.