Abstract: Truss structures are widely used in bridges, buildings and various frames, where a large
number of similar solder joints exist, aiming at the problem of low efficiency and mutual difference
on welding joints in the process of finite element modeling of bus frame, a method based on point
cloud registration is proposed to rapidly construct the welding joints of profiles. Firstly, the structure
and types of welding joints in the different parts of the bus frame are analyzed, on the basis of finite
element mesh, for a large number of joints with similar topological structure and size, the mesh and
node information are extracted, and then construct the equivalent joints and set of each part. Finally,
principal component analysis and iterative closest point (ICP) algorithm are used to register the
equivalent joint points and the corresponding cloud points on the frame, construct the welding joints
by using point cloud fusion and the former problems are solved effectively.

Key words: bus frame, fast construction of welding joint, point cloud registration, principal
component analysis, iterative closest point algorithm