含有时滞的怠速控制与输出扭矩估计器设计

Design of Idle Speed Control and Output Torgue Estimator with Time Delay

发动机由怠速工况向启动工况转换时的输出扭矩信息直接影响离合器接合过程的平顺特性。针对发动机自身和控制环节带来的时间滞后对系统性能的影响,研究了含有时滞信息的鲁棒H_∞状态反馈控制规律,使干扰信息作用下的发动机怠速工况的转速恒定且满足H_∞性能要求。进一步设计了H_∞滤波器在线估计发动机怠速时输出扭矩,为离合器的接合控制提供力矩信息。基于Simulink搭建发动机怠速系统仿真验证估计器的有效性,结果表明在扰动量出现和消失瞬间,提出的算法能保证电子节气门开度切换小,控制转速能快速稳定,且有效估计了发动机怠速时的输出扭矩,克服了时间滞后带来的性能下降的问题。

The output torque information of the engine from idle condition to start-up condition directly affects the smoothness of the clutch engagement process. For the influence of time delay rooted in the engine and control link parts on system performance, the delay robust state feedback H_∞ control law is studied to make the engine idle speed to be constant and meet performance requirements under the action of interference information.The output torque of engine idling is estimated by the designed H_∞ filter. And the torque information is provided for the engagement control of the clutch. The model of engine idle speed control and torque estimation system was established based on Simulink, and the effectiveness of the proposed estimator was verified. The results show that when the disturbances appear and disappear in an instant, the algorithm can guarantee the switch of the electronic throttle opening is small, the controlled speed can be rapidly stabilized, and the output torque of the engine at idle conditionis can be effectively estimated, which overcomes the problem of performance degradation caused by time delay.