In nine - points controller control system , it utilizes k _ ( 0 ) control force achieving the static error requirement . the condition of ko = 0 could fit the second order in most control environments 对于模型不明确的系统，我们可以同意设置k0 = 0 ，利用此时的k _ 3控制作用，把稳态误差限制在误差零带的范围内。
5.
The percolation process of wsps is taken as a unit , and a simplified contamination percolation process combined functional model is put forward , in which includes four layers as bottom sludge layer , substrate layer 把稳定塘中污染质的下渗过程看作一种单元系统，提出了概化的稳定塘中污染质下渗单元耦合功能模型，对各功能层的功能进行了描述。
