由于城市快速路入口匝道交通流具有非线性和不确定性等特点,传统的匝道控制方法难以取得满意的控制效果。文中提出了一种基于LS‐SVM 的快速路入口匝道非线性预测控制方法。建立了快速路入口匝道宏观交通流模型,设计了LS‐SVM 快速路入口匝道控制器,结合非线性反馈理论对模型反馈校正,消除了由于时变和干扰等引起的不确定性,采用仿真实例对控制方法的有效性进行了验证。仿真结果表明,提出控制方法学习速度快,控制路段的交通密度和交通流量等状态变量均可有效的跟踪到期望状态,对改善快速路的交通流运行状况有明显效果。
For the nonlinearity and uncertainty of urban expressway traffic flow ,it is difficult to obtain the satisfactory performance using general expressway ramp control methods .A new nonlinear predic‐tive method based on the LS‐SVM model is proposed for urban expressway ramp control in this paper . First ,a macroscopic traffic flow model of expressway ramp is built ;and then ,combining nonlinear feedback theory ,a controller of expressway ramp based on LS‐SVM is designed ,which eliminates the uncertainty caused by time‐varying and interference .Finally ,the effectiveness of this new method is validated by a simulation example .Simulation results show that the proposed method has a high learn‐ing speed and improve traffic flow conditions significantly ,which eliminates the effect of the external uncertain parameters on the system and control the state variables such as traffic density and traffic flow to track the desired states efficiently .