基于线特征匹配的模拟预拼装是一种桥梁钢结构构件预拼装方法，采用连接处线特征匹配进行拼接，重叠度不高且未考虑线形精度。为此，提出了一种设计数据辅助的改进方法，其先利用缩小包围盒法与切片法分别提取构件的连接处线特征与线形特征，同时结合设计数据恢复得到的线形特征，按照对应关系融合为目标特征与源特征；再基于点特征直方图和迭代最近点法分别完成粗匹配和精配准；最后利用配准结果完成构件拼接。基于仿真数据，对比角点匹配、线特征匹配、设计数据辅助等3种方法的精度，实验结果表明：设计数据辅助法能有效提高线形精度。分别使用线特征匹配法与设计数据辅助法检测上海市南横引河桥钢结构构件的加工质量，检测结果表明：所提方法具有实用性且能有效提高线形精度。

Simulation preassembly based on line feature matching is a preassembly method used for bridge steel components. In this method, components are spliced based on line feature matching of the joint. However, under this method, the overlap rate is not high and the linear accuracy is not considered. Therefore, an improved method aided by design data is proposed herein. First, the reduced bounding box and slicing methods are used to extract the line features of the joint of the components and linear features, respectively. Next, the line features, combined with those extracted from the design data, are fused into the target and source features according to their corresponding relationships. Then, coarse and fine registrations are completed based on point feature histograms and iterative closest point, respectively.Finally, component splicing is conducted using the registration results. The accuracies of the three methods of corner and line feature matching, and the method aided by design data are compared based on simulation data. Results reveal that the method aided by design data can effectively improve linear accuracy. In an actual field experiment, the processing quality of the steel components of the Shanghai Nanheng River Bridge is inspected by line feature matching and the method aided by design data, respectively. The inspection results indicate that the proposed method is practical and can effectively improve the linear accuracy.