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为解决双离合器式自动变速器换挡过程中发动机扭矩控制的时滞和参数摄动问题,提出广义预测控制实现自动变速器电控单元对发动机的扭矩请求控制。首先分析发动机扭矩控制系统的特点,建立被控对象的传递函数。利用Pade近似方法求取被控对象的离散数学模型及CARIMA模型。在此基础上构建合适的目标函数,通过使目标函数最优,获得广义预测控制器的解析解。为进一步减少算法的计算量,采用直接广义预测算法对预测方程的参数进行辨识,以提高算法的实时性。最后根据发动机台架试验数据设计了广义预测控制器和PI控制器,并通过仿真试验和硬件在环试验,对比分析了广义预测控制和PI控制在阶跃响应、斜坡响应、抗参数摄动以及换挡时的扭矩跟随等方面的性能。研究结果表明:基于广义预测控制的扭矩请求控制,在扭矩的跟随性能和抗参数摄动等方面都明显优于PI控制。因此,基于广义预测控制的扭矩请求控制方法在一定程度上降低了时滞对控制效果的影响,这对于提高双离合器车辆驾驶品质和换挡快速性有十分重要的意义。
In order to solve the problem of time delay and parameter perturbation of engine torque control in the shift process of dual clutch automatic transmission, generalized predictive control is proposed to control the torque request of the automatic transmission electronic control unit to the engine. Firstly, the characteristics of engine torque control system are analyzed and the transfer function of the controlled object is established. Using Pade Approximation Method to Find Discrete Mathematical Model and CARIMA Model of Controlled Object. Based on this, an appropriate objective function is constructed, and the analytic solution of the generalized predictive controller is obtained by optimizing the objective function. To further reduce the computational complexity of the algorithm, the direct generalized prediction algorithm is used to identify the parameters of the predictive equation to improve the real-time performance of the algorithm. Finally, the generalized predictive controller and PI controller are designed based on the experimental data of the engine bench. Simulation tests and hardware in-loop tests are carried out to compare the performance of the generalized predictive control and PI control in step response, slope response, anti-parameter perturbation and The torque at shift follows other aspects of performance. The results show that torque request control based on generalized predictive control is superior to PI control in following performance and anti-parameter perturbation of torque. Therefore, the torque request control method based on generalized predictive control can reduce the influence of time delay on the control effect to a certain extent, which is of great significance to improve the driving quality and shift speed of dual-clutch vehicles.