Research on One-Time Docking Marking Technology for Ship Block Assembly Based on B-Spline Curve Fitting Algorithm

_ In recent years, digital shipbuilding has become a primary transformation goal for major shipyards worldwide. Achieving digital assembly is at the core of digital shipbuilding. In the field of ship manufacturing, research on unified and high-precision spatial measurement technologies has gradually become a research hotspot, and studies on spatial measurement techniques and digital datum calibration technology have already been undertaken. To address the challenges of high cost and low efficiency caused by multiple closures during block assembly in ship construction, this article proposes a one-time docking marking technology for ship block assembly based on a B-spline curve fitting algorithm, leveraging a constructed spatial measurement field and benchmark digital calibration technology. Using the B-spline curve fitting algorithm, the trimming allowance is calculated by measuring feature points on the mating surface, enabling precise machining of the groove equipment. A magnetic high-efficiency marking tool, combined with a laser tracker for real-time model deviation comparison, allows accurate marking of the residual allowance line for ship block closure, significantly improving shipbuilding efficiency and docking accuracy. The efficiency of a single block closure will be significantly improved. Keywords assembly; robotics; shipyards