| For railway divisions in China,the CO-level train control system,which is mainly made up of the train operation monitoring equipment,still holds the dominant position.With the development of the railway lines,feature upgrades and additions have been continually carried out for CO-level on-board train control equipment.The development and testing of new equipment claim higher requirements for the functional integrity of the on-board equipment simulation system and the accuracy of the interface signals.Currently,the simulation systems can only output few types of signals,with low precision and incomprehensive simulation function,which cannot meet the demand of the development and testing of the on-board equipment.Therefore,researching on a new type of interface signal simulation system to meet the demand of train control system development is of great necessity.Based on the deep analysis into the functionalities of the CO-level on-board train control equipment and the interface requirements,this paper conducts the demand analysis of the simulation system by means of UML.With the help of the object-oriented design concepts,the modules and classes are designed to implement the different functionalities into different boards.Through the design of the required signals in high precision,together with the formation of a high-precision speeding algorithm on the basis of the speed sensor model analysis,the simulation system with higher interface signal precision and more comprehensive simulation functionalities is finally developed.The main results of this research are as follows.(1)The design of the DSP28335 based embedded system.With the demand analysis of the interface signals,the hardware circuits and PCBs of the DSP peripherals,as well as the corresponding software configurations are designed.The high-precision output of the interface signals,such as signals for shunting operation and function expansion box is realized.(2)Object-oriented programming.By UML modeling,C language is utilized to implement the design of the modules and classes into the embedded system to define the simulation instruction parser and hierarchical software framework.(3)The design of the high-precision speeding algorithm.Based on the analysis of the speed sensor model,the ePWM module is used to design the speed signal compensation output algorithm.Meanwhile,the ePWM parameter configuration algorithm is also proposed.The simulation of the train idling slip function is finally realized.(4)The design of the CAN communication protocol.Based on the communication theory of CAN2.0,the CAN frame content and the communication protocol between the simulation system and the host computer software is developed.Finally,the CAN communication flow is established.After debugging,the results show that the proposed interface signal simulation system can meet the current demands of the development of on-board train control equipment. |
