Design of train dynamics model in the hottest ATP

Research and implementation of train dynamics model in ATP on-board equipment simulation system

Abstract: in the automatic train control system (ATC) of urban rail transit, the automatic train protection (ATP) system plays an important role in ensuring the safety of train operation and is the basis of the automatic train control system. Among them, ATP on-board equipment is the key equipment to ensure driving safety in ATP system. It generates the train speed control curve according to the received ground information and the line information stored on the train, compares it with the actual speed of the train, monitors the train operation, and realizes the functions of overspeed protection, zero speed detection, unconscious movement protection and door protection. Based on the introduction of system simulation, this paper focuses on the establishment of dynamic model of train after one experiment in ATP on-board equipment simulation system, and puts forward the problems that should be considered in modeling. At present, the whole ATP simulation system of pellethane thermoplastic polyurethane (TPU), tecoflex thermoplastic polyurethane (TPU), tecothane thermoplastic polyurethane (TPU), isoblast etpu and carbothane thermoplastic polyurethane (TPU) has been developed and achieved the expected results

key words: automatic train protection, train dynamics, on-board ATP, modeling, simulation

1. introduction

in recent years, with the development of urban modernization, the urban scale continues to expand, the urban population gradually migrates to the suburbs, and the urban traffic pressure is increasing. The development of urban rail transit has become an effective means to solve modern urban traffic congestion. Its biggest characteristics are high operation density, short train headway, safety and punctuality. Therefore, an automatic train protection system with continuous speed display supervision and protection must be adopted to ensure driving safety and improve driving efficiency. Since the construction of Beijing Metro Line 1, the first subway in China, many lines have been built, including Beijing Metro ring line, Shanghai Metro Line 1, Shanghai Metro Line 2, Shanghai Metro Line 3, Guangzhou Metro Line 1, and many lines are under construction, including Beijing Batong line, Beijing Metro Line 5, Shenzhen Metro. The rapid development of urban rail transit has brought about an important problem, that is, as the main technology to improve the efficiency of train operation and ensure the safety of train operation, the signal control system does not have its own products, and the technology is in the backward state of turning on the plotter switch state, which is far behind the development of foreign urban rail transit signal technology. Therefore, foreign products have to be introduced, such as Westinghouse, us&s Although the products of German Siemens and other companies have enabled us to learn about the advanced technology of foreign signal systems and promoted the development of domestic signal technology through the introduction of foreign products, they have also caused a situation of large investment in engineering construction and high operating costs, making it difficult for us to improve the localization rate of subway, which is not conducive to the sustainable development of urban rail transit in China

urban rail transit signal system ATC is mainly composed of three subsystems: ATS - automatic train monitoring system, ATP - automatic train protection system, ATO - auto drive system. Automatic train protection system (ATP) is the basis of the three systems. Since the current automatic train protection system (ATP) of China's subway is basically imported from abroad, it can no longer meet the needs of the rapid development of urban rail, so the research and development of ATP system with independent intellectual property rights has been put on the agenda. In order to change the situation that the signal system is mainly imported in the construction of urban rail transit, accelerate the pace of localization and promote the application of localized equipment, the State Planning Commission approved the project for China Railway Communication and signaling Corporation in the national debt project in 1999, and developed the urban rail signal ATP system with independent intellectual property rights. At the same time, in the project of "localization development and industrialization of Automatic Train Protection (ATP) system for urban rail transit", in order to enable the development and development of ATP system to carry out testing under the corresponding simulation environment, speed up the scientific research and development speed of the project, and ensure that the design of ATP system products for urban rail transit is reasonable, safe and reliable, an ATP engineering test center is established

the traditional product development method is to put the prototype on site for testing, which not only costs a lot of human and material resources, but also takes a long time, and some on-site environments are impossible to provide. Replacing the on-site environment with the simulation environment, that is, the simulation method has become a powerful tool for system analysis, design and testing. Therefore, it is necessary to establish a computer simulation system for urban rail transit ATP in order to simulate and test all aspects of ATP system functions at all stages of actual development. ATP on-board equipment simulation system is an important part of ATP engineering test center. It is a complete functional simulation and operation process demonstration system, including simulation of train bridge, train dynamics model, on-board equipment function simulation, train operation environment and other main parts. Among them, the establishment of train dynamics model is one of the difficulties. This paper focuses on the modeling principles and key issues that should be considered, and briefly introduces its implementation method. A large number of formulas are not listed one by one

2. Principle and structure of ATP on-board equipment simulation system

among them, the train dynamics model obtains traction, braking and other control information from the simulated locomotive bridge, obtains line attributes from the equipment operation environment model, calculates the actual speed, displacement and line occupation information of the train according to the train dynamics principle, and transmits these information to other relevant modules. The simulated on-board equipment completes the generation of the train speed control mode curve and the logical calculation of some switching values, and sends the door opening information, ATP mode, braking and other related information to the simulated locomotive console for display

3. theoretical overview of simulation technology

simulation, as a comprehensive discipline, has a development history of decades. During this period, we experienced physical model simulation, analog computer simulation and digital simulation. Because simulation uses models to replace entities for experiments, it has the characteristics of economy, safety and short test cycle. These characteristics make simulation technology, as a tool for analyzing, designing systems and training personnel, widely used in almost all engineering and non engineering fields

simulation technology has developed rapidly in recent years. With the progress of computer technology, people pay more and more attention to the application of computer to system simulation. Computer simulation technology combines the two methods of experiment and analysis. When the analysis method is used in simulation experiments, its working process is generally: first, establish the mathematical model of the system; Then the simulation model of the system is established, mainly to design algorithms and convert them into computer programs, so that the mathematical model of the system can be accepted and run on the computer; Finally, the operation of the simulation model is simulated, and then according to the results of the simulation test, what can a stone do further? The mathematical model and simulation model of the system in Guangzhou shitouzao Environmental Protection Technology Co., Ltd. In simulation technology, there are mechanism modeling, identification modeling, fuzzy modeling, neural network modeling and other modeling methods. In this system, mechanism modeling method is used. Mechanism modeling method is to write a method representing its physical process according to the mechanism of the physical process of the actual system under certain hypothetical conditions and according to the corresponding theories (such as mass conservation, dynamics, etc.), combine its boundary conditions and initial conditions, and then adopt appropriate mathematical processing methods to obtain a mathematical model that can correctly reflect the dynamic and static characteristics of the object

simulation technology has the following advantages:

solve the simulation under dangerous, expensive, destructive and even non experimental conditions

it costs less and takes less time than field experiments, and reduces the funding and cycle of research and development

can simulate various environmental conditions

repeatable experiments are conducive to research and analysis

it is helpful to design, develop and research new products, show the performance of products, and train operators. (end)