基于IMC原理的电子节气门控制策略

Electronic throttle control strategy based on IMC principle

发动机系统中的电子节气门是一种典型的非线性控制对象,特别是节气门运动过程中的弹簧扭矩和摩擦阻力十分复杂,其数学模型很难精确建立,参数不易获取.针对电子节气门的非线性因素,提出一种内模控制器的设计方法.首先分析电子节气门系统的数学模型,在Matlab/Simulink仿真平台上对模型的有效性进行验证,进而以内模控制结构为基础,建立电子节气门复域模型,分析系统的非线性干扰,设计针对时变参数的内模控制器.仿真结果显示,在模型较精确的情况下,内模控制器具有优于传统PID和一般滑模控制的控制性能,而在模型失配的情况下,内模控制器的鲁棒性能够保证它的控制性能仍然优于传统PID.在所提出的内模控制器设计方法中,前馈滤波器的设计并未用到任何系统参数,但仍然能够保证理想的稳态响应和扰动响应,因此所提出方法相比于很多针对具体模型的控制策略,具有更好的实用价值.

The electronic throttle of engine is a typical nonlinear object, especially the spring torque and frictional resistance during the rotation process is very complex. Its mathematical model is difficult to be accurately established,and the parameters are not easy to be got. This paper proposes a design method of the internal model controller to solve the nonlinear factor of the electronic throttle. Firstly, the mathematical model of the electronic throttle system is analyzed, and the validity of the model is verified on the Matlab/Simulink simulation platform. Then, the electronic throttle complex field model is established based on the internal model control structure. The nonlinear interference of the system is analyzed, and the internal model controller is designed for the time-varying parameters. The simulation results show that the internal model controller has better performance than the traditional PID and the ordinary sliding mode control in the case of relatively accurate model, and the robustness of the internal model controller guarantees that its performance is still better than the traditional PID in the case of mismatched model. In the design method of the internal model controller proposed in this paper, system parameters are not required to design the feedforward filter, but the ideal steady-state response and disturbance response is still guaranteed. Therefore, this method has better practical significance compared with many model-specific control strategies.