The optimal control of automatic transmission plays an important role in the shifting smoothness and fuel economy of heavy-duty mining trucks. In this paper, a dynamic model of the powertrain system is built to study the clutch pressure control during the shifting process. A linear-quadratic optimal regulator is used to achieve the optimum control pressure of clutches, where shifting jerk and clutch friction loss are chosen to a form quadratic performance index function. Besides, a detailed solution of the linear-quadratic problem with the disturbance matrix in the state equations is provided. This paper also carries out a software simulation and verification of the normal condition (no load without slope) and the extreme condition (full load with maximum slope). Compared with the preset reference trajectory control, the simulation results show that the proposed optimal clutch pressure control can effectively reduce jerk and friction loss during the shifting process and has good robustness to different operating conditions.

中文翻译：

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重型矿用卡车自动变速器换挡过程中的最佳离合器压力控制

自动变速箱的最佳控制在重型矿用卡车的换档平稳性和燃油经济性中起着重要作用。本文建立了动力总成系统的动力学模型，以研究换档过程中的离合器压力控制。使用线性二次最佳调节器来实现离合器的最佳控制压力，其中选择换档冲击和离合器摩擦损失以形成二次性能指标函数。此外，还提供了状态方程中带有扰动矩阵的线性二次问题的详细解。本文还对正常条件（无斜率的无负载）和极端条件（最大斜率的满负载）进行了软件仿真和验证。与预设参考轨迹控制相比，