Research And Design Of ATP Safety Error Detecting Code And Rules Of Operation

Automatic Train Protection (ATP) is an important system of Automatic Train Control (ATC), and plays a significant role of train protections. ATP Vital Computer aboard is the core component of ATP aboard and a high safety level equipment which calculates the protecting curves and handles key logic judgments about safety. For conforming to ATP fault-safety principle, the International Standard IEC61508of Railway Industry makes a strict requirement for it, and Standard EN50128puts forward the specific standards and technical measures of software safety of security equipments.The software technical measure of Error Detecting Code which improves safety by adding redundancies to data information is one important technical strategy of ensuring the software safety, and an essential core software module in ATP Safety Platform. This paper researches and designs the coding mode of Error Detecting Code, the method of detecting and correcting errors and the treatment processes which use codes instead of real data in the computers.First, this paper analyses the important compositions, functions and problems about the software safety of ATP Safety Platform, distills the crucial data and key processes and researches and classifies them. Next, introduce Standard IEC61508which has guiding significances of designing ATP safety systems and Standard EN50128which is formulated based on IEC61508for software safety performance indexes. Then, according to dividing the Safety Integrity Level (SIL) and putting forward Error Detecting Code in standards, combined with the numerical characteristics of line data, used the code mode of linear block code types, design coding and functions of detecting and correcting errors by using VC++programming tools, and use Error Detecting Code to operate logics and mathematics instead of key information in the safety platform. Last, use c++test software testing tools to make tests of the Error Detecting Code software module functions, and make the performance tests and analysis of safety and real-time indexes. The results show that the software designing scheme achieves the desired safety index, and has a good real-time performance and practicality.