并联型混合动力汽车燃油经济性最优控制

Fuel Optimal Control of Parallel Hybrid Electric Vehicles

以某并联混合动力汽车(HEV)为例,建立了燃油经济性最优控制数学模型及相应的动态规划(DP)递归方程,提出了换档和发动机启动2个附加代价函数以限制频繁换档和启停发动机.为解决数值DP中“维数灾”问题,提出了搜索区域限制算法,并利用MATLAB/RTW将系统模型转换成实时仿真代码以进一步提高计算效率.对实车试验、仿真和DP结果三者进行了比较,结果表明,该方法能在可接受的时间内计算出HEV的最优性能,从而进行控制策略的评价和优化.

A mathematic model of fuel economy optimal control and its corresponding dynamic programming （DP） recursive equation were established for an existing parallel hybrid electric vehicle （HEV）. Two augmented cost functions for shifting and engine starting were proposed to prevent frequent gear shifting and engine stop-starting. To overcome the curse of dimensionality of numerical DP, an algorithm of restricting the exploring region was proposed which largely reduces the computational complexity. The system model is converted into real-time simulation code by using MATLAB/RTW to improve the computation efficiency. Comparison between the results of chassis dynamometer test, simulation and DP was performed. It proves that the proposed method is capable of computing the performance limit of the HEV within acceptable time and can be used to evaluate and optimize the control strategy.