Abstract Aiming at the low efficiency of three-point mold bending straightening, a new method of three-roll continuous straightening is proposed in this paper, which is full in consideration of the geometric features and bending characteristics of LSAW pipes. Using the characteristics of the roll straightening device, a straightness detection method for large pipes is proposed just by adding a laser displacement sensor, and the calculation model for overall deflection based on local deflection is established. Based on the detected deflection data, a piecewise fitting algorithm with constraints by introducing the Kuhn-Tucker condition is proposed for straightness calculation, and a simple polynomial fitting method with fourth order is determined for the calculation of curvature and straightening moment. Further, using the semi-automatic experimental prototype for small pipes, the deflection detection experiments show that the overall deflection error is less than 3.5% compared with that of CMM, the piecewise fitting results show that the ideal order of the mid-segment is 10-th, and the three-roll continuous straightening experiments show that the novel method can correct the straightness to less than 0.2%, meeting the standard requirements.

中文翻译：

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LSAW管材三辊连续矫直过程挠度检测与曲线拟合

摘要 针对三点模具弯曲矫直效率低的问题，充分考虑了LSAW管材的几何特征和弯曲特性，提出了一种三辊连续矫直的新方法。利用轧辊矫直装置的特点，提出了一种仅增加激光位移传感器的大型管材直线度检测方法，建立了基于局部挠度的整体挠度计算模型。基于检测到的挠度数据，提出了一种引入Kuhn-Tucker条件约束的分段拟合算法进行直线度计算，并确定了一种简单的四阶多项式拟合方法来计算曲率和矫直力矩。更多，