本文探讨一种组合模型,对自动线上待加工孔的尺寸进行预报。它能综合反映孔径尺寸的确定性变化和随机性变化的情况,可使在线预测更为准确。同时提出了用实际工艺能力系数制订控制界限的原则,以及阐述了与此有关的模型定阶等问题。图6幅，表1个。参考文献5种。 This article explores a combined model that predicts the size of holes to be machined automatically. It can comprehensively reflect the deterministic change of aperture size and the change of randomness, which can make the online forecast more accurate. At the same time, the paper puts forward the principle of setting the control limit by the actual technology capability coefficient, and expounds the problems such as the order of the model related to this. Figure 6, Table 1. 5 kinds of references.