在航发机匣类零件自动化组线升级改造中，零点定位系统和辅助找正台等新设备的引入大幅度提高了生产效率，但也导致了多工序加工中的系统误差增加，为了解决新的系统误差对于加工精度损失带来的不利影响。研究了不确定性输入下的找正系统误差建模与精度优化方法，首先，构建考虑零点定位系统子母盘差异的装配偏差分析模型，并设计K-S检验验证模型的准确性；基于此，分别分析了多子盘-母盘互换过程中的精度损失规律，之后，定义了基于输出分布差异与超差率差异的精度损失量化函数，通过对找正系统的基座结构进行优化，将精度损失由原先的11.53%降低到了2.33%；同时，将由加工基准和定位基准不一致导致的工件径跳分布差异由0.117降低到0.039；大大提高了零点装夹找正系统的性能，为产线的装夹定位精度分析和优化提供了理论支持。

In upgrading the aircraft gearbox parts automated grouping line, the introduction of new equipment like the zero-point positioning system and alignment table significantly boosts production efficiency. However, it also brings about increased systematic errors in multi-process machining, affecting machining accuracy. To address these issues, an error modeling and accuracy optimization method for the squaring system under uncertainty input was developed. Firstly, an assembly deviation analysis model, considering differences among sub-master discs of the zeropoint positioning system, was constructed and validated using the K-S test. Subsequently, the study analyzed the accuracy loss during the interchangeability of multiple sub-master discs with master discs. A quantitative function for accuracy loss based on differences in output distribution and out of Spec was defined. Through optimization of the structure of alignment table base, accuracy loss was reduced from 11.53% to 2.33%. Simultaneously, the variation in workpiece runout due to inconsistencies between machining and positioning datum was reduced from 0.117 to 0.039. This significantly improved the performance of the zero-point clamping and setting system, providing essential theoretical support for the analysis and optimization of clamping and positioning accuracy in the production line.