| Urban signal intersection has partition effect to traffic flow, vehicles often accelerate, decelerate, idle and park here, that will cause a large number of motor vehicle emissions and fuel consumption. Dynamic speed control method, as a method of green driving, is able to provide dynamic and real-time driving strategy for vehicle drivers. Compared with the traditional green driving method, the advantages of dynamic speed control method are that, mature information publish technology and communication technology makes it more practical, and costs have more advantages relative to the improvement of fuel and vehicle modification. Moreover, variable speed limit method is one of a mature method of dynamic speed control method. By set VMS on the side of the road, dynamic speed recommended value is provided to drivers, and then control their modes of operation. Therefore, green driving speed dynamic signal intersection control method based on variable speed limits is significance.On the basis of the analysis of motor vehicle emissions and fuel consumption model and variable speed limit method, and in view of the shortages of control constraints and the lack of signal intersection as the background of existing models and methods, this article proposes a green driving signal intersection control method based on variable speed limits. Leader car of a platoon,is selected according to the relationship of time and space, and the leader car drivers will obtain the speed recommended value by the use of VMS board to accelerate and decelerate, in order to pass the signal intersection from the beginning of green time at the next signal period. This method can improve the efficiency of traffic, at the same time to achieve the effect of energy conservation and emissions reduction.According to the constrains of vehicle operation characteristics and space-time relationship relative to the strategies of signal intersection green driving control method based on variable speed limit, with the setting position of VMS as decision variables, and the least motor vehicle emissions and fuel consumption as objective, the corresponding green driving speed dynamic signal intersection control optimization model is built to comprehensive descript the speed dynamic control problem at signal intersection relative to VMS setting position.Based on the modeling, the optimization model is solved by genetic algorithm. Using GATBX toolbox in MATLAB to get the best VMS setting position, and then set the corresponding parameters for simulate the green driving speed dynamic signal intersection control strategy in the MATLAB. In the end, CO, HC and Nox emissions and fuel consumption of intersection is analyzed in different traffic situations, and we finally find that in traffic is close to the saturated condition, the method can effectively improve the efficiency of traffic, and energy conservation and emissions reduction effect is obvious in a large value of traffic conditions. |
