Studies On Multi-Phase Intelligent Traffic Controller

With the development of automotive industry and the improvement of peoples'life, traffic congestion has gradually become the bottleneck of the development ofsociety and economy in modern city. Due to the heavily nonlinear, stochastic,time-variant and uncertain characteristics of the urban traffic system, intelligentcontrol technique for urban roadway traffic is an important topic in control domainand traffic engineering domain.In this thesis a multi-phase intelligent traffic control system based on loop-coilinductive vehicle detector was designed to resolve the traffic control problems inmedium and small-sized cities in our country. The system was designed by modularand scalable mode, and easy to be constructed to different types of traffic controlsystems freely. In the thesis we introduced the hardware and software design for thecore system and vehicle detector system, and presented a new two-direction greenwave intelligent control strategy. The goal of control arithmetic was to achieve thezero stop of the up-run and down-run vehicles in the trunk and to make the vehicleaverage delay time shortest. Practical application indicated a good result.The main contributions of this thesis were as follows:1. We made an overview on the urban traffic control system, includinggeneration and development, and outlined the structure and characteristics ofup-to-date traffic control systems adopted widely in cities home and abroad. We alsointroduced the current control strategies in traffic system and analysised theirefficiency and deficiency.2. An intelligent traffic control system especially for medium and small-sizedcities in our country was presented. Structure of the system, function andinterconnection of every part of the system were illustrated.3. A multi-phase intelligent traffic control system based on loop-coil inductivevehicle detector was designed. The controller was designed modularly and it'shardware parts were scalable. The controller could be constructed to different types oftraffic control systems freely to meet the current need. The hardware and softwaredesign for the core system and vehicle detector system was also introduced4. We presented the idea of periodic setting technology for the vehicle detectingcard and realized the line-by-line scan of every channel. The method could avoid thesignal coupling in different channel and ensure the stability of the whole system. 5. The merit and demerit of current traffic control algorithms were discussed anda new two-direction green wave intelligent control strategy was presented. Thisalgorithm used the Late-On and Early-Off in the laeotropic phase to coordinate thegreen wave of up-run and down-run. Practical application indicated a evidentaldecrease of stopping rate and delay time.