Compared with existing approaches, auto-companding can help in controlling modeling error and reducing the number of basis functions employed. 与已有方法相比，采用自动压扩技术可以有效的控制模型误差并减少采用的基函数的个数，从而可以达到更好的建模效果。
Firstly, an average performance index containing tracking error and control energy over a class of additive model errors is defined. 首先针对一类相加模型误差的描述，定义了一个平均意义上的包含跟踪误差和控制能量的性能指标。
