Chen Xiangxian

Original article: A component-based topology model for railway interlocking systems

Abstract: Writing interlocking logic is an important part of designing a railway interlocking system. In this paper a new method which increases the efficiency of writing interlocking logic is introduced. That is describing interlocking rules and station topology separately, and producing interlocking logic automatically by associating topology data with interlocking rules using software tools. As interlocking rules remain the same, the work for a new station is to specify the topology data only and the new interlocking logic can be generated automatically. This paper emphasizes on a component-based model used to describe the topology of the station. In this model, a railway station is abstracted as a set of connected components, and route information can be deduced from the topology data. The model of station topology makes the idea of producing interlocking logic automatically possible.

Train Speed Control Algorithm Based on PID Controller and Single-Neuron PID Controller

Automatic train operating (ATO) system has two main functions—speed control and stopping control. In this paper, the algorithm of train speed control, based on PID controller and single-neuron PID controller is designed and simulated.

Automatic Generation of Relay Logic for Interlocking System Based on Statecharts

Computer-based Interlocking System (CIS) is a kind of widely applied safety-critical system in current signaling industry. CIS always uses relay logic to describe interlocking safety logic. Normally, all logic is designed by experienced signaling engineer manually, this develop mode is low-efficient and expensive. This paper presents a new logic design model. In this new model, a component-based model is used to describe topology of station layout, the topology data is analyzed and state charts are used to describe safety logic of interlocking. Finally the state charts are transformed to relay logic. The entire logic generating procedure can be fulfilled by software tools automatically, so efficiency is improved greatly. The introduction of state charts also makes formal verification of safety logic possible, which can guarantee that the generated logic is safe.

Design of Bill Acceptor for Automatic Fare Collecion of Rail Transit

To solve the problem of the not high localization degree of Chinas urban rail transit automatic fare collection systems, a bill acceptor is designed for the rail transit AFC systems. The bill acceptor makes use of magnetic and optical inspection circuit to extract the banknote features like magnetic ink, UV fluorescence, and infrared image. And then apply the PCA algorithm to reduce the dimensionality and build the template. Define two Euclidean distances between the test banknote and the template as the similarity to discriminate the currency. The tests have shown the effectiveness of the system. The banknote jammed rate and receive rate can achieve the industry engineering requirement and the processing speed is significantly improved.