Research And Implementation Of25Hz Phase Sensitive Track Circuit Electronic Receiver

As the signal basic security equipment, track circuit provides line idle and integrity and other safety conditions for the command and control systems, such as train control and interlocking system.25Hz phase-sensitive track circuits possess good frequency selectivity and phase selectivity, which result in the extensive use in Track circuit within station electrified in our country. As the development and application of the coded track circuit within the station, traditional Binary-relay has been gradually replaced by Microelectronics receiver. Due to the continuous development of the electronic technique, full-electronic of the railway system and signal equipment has been made into a new trend. To satisfy theintelligentize and informationize of the full-electronic computer interlocking system, this paper accomplishes the design of25Hz phase-sensitive trackcircuits which are based on Digital Signal Processing(DSP) technique and distributed communications network.At first, this paper proposes a project design combining the needs of the system. This system Follows Double2-vote-2design and adopts CAN bus distributed communication network as its communication program, Infinite Impulse Response(IIR) software filtering as its filtering method, and correlation function algorithm as its core algorithm. It also conducts principle analysis and the simulation comparison of the system.Secondly, this paper put an emphasis on introducing the design of the25Hz phase-sensitive track circuits; in aspects of the both the hardware circuit design and the software design. The processor chip uses a floating point Digital Signal Processor (DSP) C28346, which has fast calculation speed and large internal storage, and guarantees the executive efficiency of the digital signal processing algorithm. The hardware circuit design includes power circuit, reset circuit, clock circuit, Joint Test Action Group (JTAG) circuit, Controller Area Network (CAN) interface circuit and LED indicator light circuit. The software design includes safety check module, the module of AD gathers, inspection module and CAN communication module.At last, this paper sets up a testing platform of the25Hz phase-sensitive track circuits, which can test the function of the receiver and the CAN communication fault handling. Results shows that the25Hz phase-sensitive track circuits is able to detect the occupied state of the track section and submit the information to the computer interlocking system, which achieves the requirements of the system design.