基于改进全局优化算法的轮毂液压动力系统能量管理策略

现有针对轮毂液压混合动力系统的能量管理策略均为结合研究人员经验与发动机最优工作区域的简单控制，暂未见优化控制策略的应用，导致实际控制值与最优控制值的偏差较大，无法充分发挥该系统的节油能力。基于此，针对该系统提出了一种基于改进全局优化算法的能量管理策略，探寻该系统的理论最大节油量，进一步挖掘该系统的节能潜力。首先，该策略建立了基于车速-蓄能器荷电状态（SOC）自适应调节等效油耗因子的方法计算目标函数中的罚函数，从而提高系统的制动回收能力，避免计算结果陷入局部最优；随后，根据轮毂液压混合动力系统各模式工作点相对固定的特性，实现了控制变量降维；最后以实测数据进行了仿真测验。结果显示：比起传统的全局最优策略，该方法可以进一步实现3.36%的节油效果；同时，在实现节油的基础上，经过控制变量降维后计算时间减少了35%，而计算精度基本不受影响。

Energy Management Strategy of Hydraulic Hub-motor Hybrid System Based on Improved Global Optimization Algorithm

The existing strategies for the energy management of hydraulic hub-motor hybrid systems are simple to control, with the experience of researchers and the optimal working area of the engine. The application of an optimal control strategy has not yet been presented, resulting in a large deviation between the actual control value and the optimal control value, thereby weakening the fuel-saving ability of the system. This study proposes an energy management strategy based on an improved global optimization algorithm for the hydraulic hub-motor hybrid system, to explore the theoretical maximum fuel saving of the system, and further tap the energy-saving potential of the system. An adaptive equivalent fuel consumption factor based on the vehicle speed and accumulator state of charge (SOC) was established to calculate the penalty function in the objective function, thereby improving the braking recovery ability of the system and avoiding the results falling into local optimization. Based on the relatively fixed working points of each mode in the hydraulic hub-motor hybrid system, dimension reduction for control variables was realized. Finally, a simulation test was carried out based on measured data. The results show that, compared with that of the traditional global optimal strategy, the ratio of oil saving is up to 3.36%, and the calculation time can be reduced by 35% without affecting the accuracy after the dimension reduction of the control variables.