天然气发动机自适应控制软件抗干扰设计

为提高天然气发动机的动力性、经济性和排放性能,采用了缸内直接喷射天然气的方法,并对点火正时和空燃比实施了自适应控制。重点分析了以发动机自身转速为反馈信号进行自适应控制的天然气发动机干扰源的特殊性,提出并实施了因素抖动和抖动循环等寻优控制策略。采用数字滤波、系统复位与监控等措施,成功地进行了软件抗干扰可靠性设计。通过与硬件控制系统设计相结合,在一台单缸天然气发动机上进行了可行性验证与应用。结果表明:本设计可以滤除发动机外界负荷缓变的干扰,能实现发动机循环变动干扰的平均化处理与快速衰减,有效解决了外界负荷突变和外界强电磁干扰带来的影响。

Anti-disturbing design of self-adaptive control softwares for CNG engine

For raising the power performance, improving the fuel economy and reducing the emissions of nature-gas engine, the in-cylinder direct injection of natural gas and self-adaptive control of ignition timing and air-fuel ratio were adopted. The special features of disturbing resources of the self-adaptive controlled CNG engine which used the engine speed as feedback signal were analyzed, the optimal control strategy including the factor-dithering and the dither-cycle was proposed and had been carried out, a digital-filter and a watch-dog were also adopted to finish the anti-disturbing design. Combining with the hardware system design, the anti-disfurbing software feasibility was verified in a single cylinder natural gas engine, and results indicate that it can filter the disturbance of the engine load slow changes, realize averaging and fast damping the interference from engine cycle-variation, and resolve effectively the influence of the sudden changes in the engine load and the outside strong electromagnetic waves.