The Research And Design Of Road Traffic Signal Controller With High Reliability And Safety

Road traffic signal controller is an important part of traffic signal control system,its safety and reliability of which plays a very important role in the normal operation of the city's transportation and the safety of people's life.However,current traffic signal controllers in many domestic cities' traffic intersections are of simple structure,frequent breakdowns,and most of them without security system.Therefore,in order to solve the security problems of the traditional signal controller,this dissertation designed a safer and more reliable road traffic signal controller and realized with both hardware and software.It uses the ?C/OS_? real-time operating system combining the FPGA hardware circuit as the top management system.When system's software crashes,the controller is still managed by FPGA hardware circuit in safe mode.By this way,the road traffic signal controller is safer and more reliable,which reduces the traffic problems.First of all,current state of the signal controller and the traffic control theories are introduced briefly in this dissertation.Then the safety and reliability of the traffic signal controller in the hardware and software side is well analyzed.And in the light of the features of hardware structure and system software,the safe and reliable measures of the signal controller are proposed.Secondly,according to the functional requirements and the safe and reliable measures of the traffic signal controller,the overall design scheme is proposed,which mainly divided into hardware design and software design.The hardware design includes:modules of the STM32 master control system,modules of FPGA safety assistant system,and the driver module of signal lamps.Software design mainly includes:main task of the real-time operating system,serial port communication task,real-time control task of signal controller,intersection signal characteristics data download task,time management task,real-time self-inspection task and the each modules of FPGA assistant system,etc.The overall correlation is:on the normal status of master,data can be transmitted through a serial port between controller and PC,and the signal of lamps is output to the driver module by FPGA controlled by real-time control task with different control schemes in different time.When the master control system crashed,the lamp signal is generated by the FPGA under safe mode.The FPGA assistant system also has the function of signal collision detection and manual performance.Finally,the signal controller debugging and analysis are listed.Each hardware module is debugged.Based on the correctness of hardware design,software function debugging is processed in each module.After debugging each module,the master control system,assistant system and light drive module is connected to the whole test.The results of the test show that the design of road traffic signal controller is not only meet the requirements of intelligent transportation with high safety and reliability,but also have higher application value.