An iterative path compensation method for double-sided robotic roller forming of compact thin-walled profiles

High-precision robotic forming of ultrahigh strength materials is challenging due to the significant stiffness deformation of industrial robots. In this work, a double-sided robotic roller forming process was developed to form ultrahigh strength steels to thin-walled profiles. Synchronized laser heating prior to plastic deformation was initially introduced as a means of reducing the required forming forces. Considering the varying forming forces during the compensation of stiffness-deformation-induced path deviation, an iterative path compensation method was proposed and implemented to enable continuous adjustments of path compensation values, utilizing a robot stiffness model and the correlation between compensation values and forming forces. Results show that laser heating has a significant positive effect on reducing springback angle due to the decrease of forming forces, while the path compensation facilitates the forming of compact thin-walled profiles with sharp bending radii. It is validated that the proposed method for iterative path compensation is conducive to the determination of the optimized path compensation values with limited iterations.