Hardware Design And Implementation For Point Switch Monitoring Unit

With the rapid development of railway transportation in China,the running speed of trains has become faster,and the operating efficiency of trains has been greatly improved.In order to guarantee the safe operation of trains,operation safety requirements of trains should increase correspondingly.Point switch is a kind of electrical power equipment used to flip railway turnouts’ tougue rail,real-time monitoring whether the point switch has flip the railway turnouts in right place,which is very important for trains’ safe operation.Gap monitoring system of point switch can effectively monitor gap state of point switch,which lets gap monitoring system has broad application prospect.However,the existing gap monitoring system of point switch has certain deficiencies in transmission,detection method and system compatibility,which leads it hard to meet modern requirements for monitoring system.In view of the above shortcomings,this thesis designs a point switch monitoring unit based on ARM processor.It can not only collect video information of point switch gap,motor state information,temperature and humidity information,vibration information,but also it can transmit the collected information through the power line to the upper computer for processing.In addition,the point switch monitoring unit designed in this paper also supports Flash online programming and USB,eMMC and other system startup mode,which make it easy to update the system program.Firstly,this thesis introduces the research status of the point switch monitoring unit and the development background of related technology,then carries out the demand analysis and puts forward the overall design of the point switch monitoring unit.Next,this thesis introduces the hardware circuit design of the main function modules in detail,including core processor module,Ethernet module,sensor module,communication module,reserved interface circuit and power supply module,etc.Whereafter,combined with the knowledge of electromagnetic compatibility and signal integrity,this thesis introduces the selection of the stack,the key signal impedance control,layout and wiring in PCB design.Afterwards,the thesis introduces the test work of function and performance.At last,the conclusion is given and the development direction of point switch monitoring unit is discussed.