TMR Application of Train Control System For High Reliability

초록

The railway is the means of public transportation and the accidents of railway cause heavy casualties and a lot of financial losses. Thus, safety issues have been a primary concern in the development of railway system. Especially, the train control system for railway system is very important because the principal intent of a train control system is to prevent collisions when trains are traveling on the same track, either in the same direction or in the opposite direction. In high reliability system, the fault tolerant techniques, such as Triple Modular Redundancy (TMR) have investigated since it started several decades ago. This paper deals with the prototype TMR system design to provide the train control system with the normal function continuously if one of CPUs is out of order. To minimize the voting delay time and the data sharing time, the high performance 300MHz DSP (Digital Signal Processing) chip was used and the input was synchronized to provide all of CPUs with the same input. In this paper, the prototype TMR system used the 2 out of 3 voting algorithm. Thus we could verify the normal output when the one of the CPUs is out of order and the result of two CPUs is same.