Research On The Fundamental Theories And Key Techniques Of The Bandwidth-based Arterial Signal Coordination Control

In recent years,traffic congestion has become one of the important factors restricting the urban socio-economic development.As an important approach applied in modern traffic management and control,bandwidth-oriented signal coordination control has tremendous importance in alleviating the traffic pressure and improving the passing efficiency of arterials.Considering the defects in the existing theory and method of bandwidth-based signal coordination and the actual demands in the traffic signal control practice,this dissertation has researched and discussed the following questions,including the improvement of algebraic algorithm,presentation of coordination method for double-cycle control,establishment of coordination model for speed fluctuation,development of coordination model for left-turn traffic flows and establishment of coordination model with phase optimization.The main scientific research and research results in this dissertation are as follows.1.A general algebraic algorithm for maximizing bidirectional progression bandwidths is proposed.First of all,the value range of adjacent ideal interval is determined.Secondly,formulas for calculating the outbound offset green ratio and inbound one are deduced.Further,formulas for calculating the green ratio above and below the ideal central line of the green time are proposed.Finally,the optimized model of maximum progression bandwidth is established with the maximum sum of the bidirectional progression bandwidths being the optimization objective and the outbound and inbound designed speed and signal cycle being the optimization variables.The proposed general algebraic algorithm is verified by an example,which shows that the general algebraic algorithm could break through the limitation of fixed values of designed progression speed and has a better generality and practicality.2.A new loop integer constraint suitable for double-cycle coordination control is derived firstly.The deficiencies of the existing methods are analyzed thoroughly secondly.Thirdly,a double-cycle signal coordination model with maximizing the sum of weighting bi-directional progression bandwidths is established.Finally,taking actual arterial for example,traffic simulation is used to make comparison between the proposed model and MULTIBAND in high,medium and low traffic demand.The result of contrast shows that the proposed model has a better effectiveness and practicality.3.In the environment of vehicle-vehicle and vehicle-road communication,a method for double-cycle green wave coordinated control,which is based on speed guidance,is proposed.Cases are designed to compare the passing effect of the before and after acceleration and deceleration guidance.The simulated results shows that acceleration guidance can reduce travel time,delay and stops significantly;and deceleration guidance can keep travel time and delay from rising and reduce stops significantly meanwhile.This provides a new thinking and method for solving the deficiency of traditional double-cycle green wave coordinated control method.4.Considering that the travel speed of platoons fluctuates in a range,the non-stop constraints that the lead vehicle of platoon travels at a higher speed and the trail vehicle of platoon travels at a lower speed are analyzed.The formulas of calculating fluctuation percentage of speed are proposed.An arterial coordination control model-a goal programming model,which firstly aims at maximizing the sum of the bidirectional green band and secondly maximizing the sum of the fluctuation percentage of speed,is developed.A sequential algorithm and genetic algorithm are designed to solve the proposed model.Finally,traffic simulation is used to verify the effectiveness and practicality of the proposed model through a numerical example.5.Taking left-turn traffic flows as the main coordination objects,a general maximum progression model to concurrently synchronize left-turn and through traffic flows is established.The proposed general model can simultaneously optimize offsets and phase sequences.The proposed model can deal with all the patterns of the left-turn phases by introducing external binary variables into the constraints,i.e.,these variables allow all the patterns of the left-turn phases to be dealt with a single formulation,displaying a decent generality.Finally,taking actual arterial for example,traffic simulation is used to make comparison between the proposed model and MULTIBAND.The result of contrast shows that the proposed model can achieve better traffic control.6.Overlapping phase and split phase are two typical phase design patterns of signalized intersections.The existing bandwidth-oriented models take the overlapping phase as their research objects and further optimize the sequences of the overlapping phase,ignoring the split phase.Therefore,a new general signal progression model with phase optimization is developed.The new general model firstly optimizes the phase patterns and then optimizes the phase sequences of the optimal phase pattern,displaying a better applicability.Finally,traffic simulation is used to make comparison between the proposed model and MULTIBAND through a case study,which verifies the effectiveness and practicality of the proposed model.