智能车经济性起步车速规划研究

智能车的车速决策影响燃油经济性。以起步阶段加速工况的燃油经济性为优化目标,建立了瞬态燃油消耗模型,并提出了基于该模型的经济性换挡规律制定方法;根据车辆纵向动力学方程,建立了基于前向欧拉离散方法的车速状态转移方程,以及确定相应的初末约束条件、边界条件;基于动态规划最优性原理,提出了智能车起步过程的经济性车速规划方法,建立了基于速度状态搜索策略;根据Matlab/Simulink和CarSim联合仿真,对比了典型驾驶员速度跟随模式的燃油消耗水平,结果表明,基于动态规划优化后的经济性车速及相应的挡位序列具有良好的节油特性,可为智能车经济驾驶的车速规划及挡位规划提供指导。

Research on Economic Speed Planning of Intelligent Vehicle for Starting Stage

The speed profile of an intelligent vehicle affects the fuel economy.To optimize the fuel economy of the vehicle under the acceleration condition in the starting stage,the transient fuel consumption model is established and the economic shift schedule method based on this model is proposed.Based on the longitudinal dynamic equation,the vehicle speed recursive equation based on the forward Euler discrete method is established,and the initial/final constraints and boundary conditions are given.Based on the principle of optimality of dynamic programming(DP),an economic speed planning method for the starting stage of intelligent vehicle is proposed,and correspondingly a speed search strategy is developed.Based on the joint simulation experiment of Matlab/Simulink and CarSim,the fuel consumption level of typical driver speed following mode is compared.The results show that the optimized economic speed profile and corresponding gear sequence by DP algorithm have good fuel-saving characteristics,which can provide guidance for the speed planning and gear planning of intelligent vehicle s eco-driving.