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Towards Controlled Three-Dimensional Laser Forming
S.P. Edwardson, J. Griffiths, G. Dearden and K.G. Watkins

Two-dimensional (2-D) laser forming (LF) can currently control bend angle, with reasonably accurate results, in various materials including aerospace alloys. However, this is a different situation for three-dimensional (3-D) LF. To advance this process further for realistic forming applications and for straightening and aligning operations in a manufacturing industry it is necessary to consider larger scale controlled 3-D LF. The work presented in this paper uses a predictive and adaptive approach to control the LF of mild steel and aluminium sheet into a desired surface. Key to the control of the process was the development of a predictive model to give scan strategies based on a required geometry and the surface error. The forming rate and distribution of the magnitude of forming across the surface were controlled in the closed loop by the process speed. When the geometry is not formed within one pass, an incremental adaptive approach is used for subsequent passes, utilising the error between the current and desired geometry to give a new scan strategy, thus any unwanted distortion due to material variability can be accounted for and distortion control and removal is possible.

Keywords: Laser forming (LF), bending, bend angle, three-dimensional (3-D), closed loop

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