Design And Realization Of Improved Safety Control Receiver Based On High Alphabet System

Safety control system includes two working modes which are automatic safety control mode and remote safety control mode.Automatic safety control mode could be easily influenced by the communication links between satellites and aircrafts while the latter might make errors due to some uncertain man-made factors.To solve the problem above,a design method of improved safety control receiver which integrates two modes together is provided in this paper.It includes the research on optimizing high alphebat system of remote safety control mode and the improved design of software and hardware of traditional safety control receiver.Advantages and disadvantages of automatic safety control and remote safety control mode are analyzed in this paper.In the same time,differences between two signal systems of remote safety control mode are analyzed,then the safety control receiver are improved with the design experiences which are accumulated recent years.To solve the problem that the safety control instruction could not be detected correctly due to incorrect detection of the single-sound,this paper summarizes the method of choosing the proper system sampling rate under the low FFT sampling number by the analysis of barrier effect.Through adequate simulation and analysis,the fact that the combination of alphebat of safety control instructions could be detected correctly and accurately by using the sampling rate which is choozen based on the method mentioned above could be verified in this paper.To solve the problem that single working mode which means that safety control system is working in either automatic safety control mode or remote safety control mode might have bad effects on the reliability of safety control system,the safety control receiver based on the PCM-PSK-FM modulation system is improved in this paper.Firstly,the modulation of safety control instructions are based on high alphabet system so that the reliability of safety control system could be improved;then the hardware and software of the receiver are improved so that the data used for automatic safety control mode could be transmitted to the receiver through RS422 interface,then two safety control working modes are integrated together.The instruction output circuit is used in common by two working modes while the software of each mode would work separately which means our receiver would respond to the safety control instructions regardless of the mode from which the instruction be sent.Compared with tranditional safety control receiver,improved receiver has some advantages on the reliability,timeliness and security.