摘要宽域废气氧(Universal Exhaust Gas Oxygen,缩写为UEGO)传感器可以在很宽的空燃比范围内提供有效的氧含量信号,它的结构特殊,必须配以控制器才能使用。利用鲁棒PID算法控制UEGO控制器中泵电压的大小和方向,并将泵电压反馈作用在UEGO传感器上。检测UEGO传感器上的泵电流,并设计非线性校正环节对其进行校正,校正输出值即为过量空气系数(λ)。利用dSPACE实时仿真系统实现UEGO控制器,并在汽车化油器发动机台架上进行相关实验。实验数据表明,在λ值静态和动态变化时,UEGO控制器都具有良好的鲁棒性和运行性能,响应快速且精度良好。
Abstract:Universal Exhaust Gas Oxygen (UEGO) Sensor can effectively provide the information of the oxygen content within wide air-fuel ratio scope. Due to its special structure, it cannot work normally without a controller. Therefore a robust PID algorithm is applied to the controller of UEGO sensor for controlling the value and direction of the pump cell voltage and exerting a feedback control action on the sensor. The pump cell current is detected and a nonlinear corrector for the pump cell current is designed, results of corrector is the excess air factor(λ). UEGO controller is implemented by means of dSPACE real time simulation system, and experiments are conducted on a carburetor engine. Experimental results show that the UEGO controller has strong robustness and good running performance. It can archive quick response and precision measurement whenλchanges in static and dynamic modes.