复合功率分流系统发动机起动H∞鲁棒优化控制

Engine Start-up H∞Robust Optimal Control of the Compound Power-Split System

为改善复合功率分流混合动力系统纯电动至混合动力模式切换过程的车辆驾驶平顺性,同时确保在模型不确定和外部干扰条件下切换控制的鲁棒性,本文中提出了一种发动机起动H∞鲁棒控制策略。首先,建立复合功率分流混合动力系统动力学模型,并对纯电动至混合动力模式切换过程进行分析。其次,以车辆驾驶平顺性和发动机起动时间为优化指标,通过动态规划求解发动机最优拖转转速曲线。然后,考虑到输入轴阻尼参数摄动、驾驶员输入、道路负载、输出端转速的不确定性变化和发动机转速量测噪声的干扰,设计了发动机起动H∞鲁棒控制器。最后,通过离线仿真和台架试验对所提出的控制策略进行验证。结果表明,该策略能有效将冲击度降低至11.52 m/s^3以内,同时对模型不确定性和外部干扰有较强的抑制能力。

To improve the vehicle ride comfort during switching from pure electric mode to e-CVT mode of the compound power-split hybrid system,while ensuring the robustness of switching control under the conditions of model uncertainty and external disturbance,an engine start-up H∞robust control strategy is proposed.Firstly,a dynamic model of the compound power-split hybrid system is established,and the switching process from pure electric mode to e-CVT mode is analyzed.Secondly,an optimal crank curve of engine speed is designed based on dynamic programming taking vehicle ride comfort and engine start-up time as optimization indexes.Then,considering the damping perturbation of input shaft,the uncertainty of driver input,road load and output speed,as well as the disturbance of measurement noise,an engine start-up H∞robust controller is developed.Finally,offline simulation and bench test are conducted to verify the proposed strategy.The results show that the strategy can effectively reduce the vehicle jerk to below 11.52 m/s^3,and has strong ability to restrain the model uncertainty and external disturbance.