The Research Of Automatic Block Interval Distributed Signal Control Unit

Automatic block interval signal display correctly is the basis of trains' safe and efficient operation. Most existing signal control architectures adopt centralized control method, this control architecture's signal is outside, and other equipment is concentrated in the interior.Indoor and outdoor equipment connected by cable as transmission medium, this kind of signal need spend a lot of cable and is easy to mix lines and is vulnerable to lightning shock, its cost is also high. The cable connection distance is generally limited to 10 km. Combined with computer, network, communication and microelectronics technology's development, it is very important to develop a distributed signal control system which will move the control unit to the wayside so that the signal could be controlled by distributed remote control.In this paper, the structure of the two take two full electronic light control unit is designed which is base on the interval signal control architecture for railway signal system background, combined with block section signal interlocking control conditions during the train operation, to block section trackside signals as the research object, using the field bus control technology, development of new electronic switching device. Trackside intelligent monitoring and control integrated design requirements can realize the scene maintenance free,convenient maintenance management, satisfy the operation conditions of block section train,and also can realize the light open and close safely and reliably.In this paper, on the basis of overall design scheme of signal control unit and its technical characteristics, software and hardware are designed in detail, and the reliability and safety of control unit are analyzed. Signal control unit and control host adopt dual redundant CAN bus communication mode to realize lighting command, light state and fault information two-way interactive control unit itself. Two processors inside the control unit verify light the signal status information that they have received are consistent with the collected data though synchronous communication, and the accuracy of the light signal status information and orders are ensured to further. The same current detection circuit is accessed to the control unit circuit to line and line of the back for lighting circuit current information collection, so that the condition of the circuit point lights is determined. Control unit realizes the input power and output power of isolation through designing the independent power supply circuit, further reduces the mutual interference of each unit circuit. The control unit has fault self-diagnosis function, conforms to the principle of signal infrastructure fail safe. In this paper, the unit reliability and safety analysis are controlled by using the markov model,established mathematical model is simulated by the use of the Matlab, and the reliability, the safety degree of the control unit and fault-safety simulation graph are got. The result showsthat the designs of the signal control unit meets the requirements in terms of reliability, safety and fault-safety, it has good application value.