The Surface Measurement And Registration On The Process Of Multi-Point Closed-loop Forming

Multi-point forming (MPF) is an advanced flexible manufacturing technique for sheet metal forming. Its main idea is dividing the curved surface of the traditional stamping dies into many pairs of matrices of elements, and then the three-dimensional shape of sheet metal is formed by the curved surface of elements. The position and movement of each element is controlled independently in real time by the computer. Adjusting the relative positions of the elements, one can easily shape the desired surface according to the design, and then the speedy and flexible sheet metal forming is realized. The MPF technology can be applied extensively in many fields, such as vehicles covered pieces, aircraft coving, hull panels, pressure vessels, architectural panels, medical alloyed-rehabilitation of various shapes and so on.In process of Multi-Point Forming (MPF) for sheet metal parts, there is shape error between workpiece formed and objective model due to springback and positioning error, how to measure the workpiece's shape and register it with objective model is one of key problems in improving forming precision of MPF. The laser measurement technology which based on modern photics, is a modern measure technology and integrate the electronics, computer image technology, information disposed technology, computer vision technology and so on. It can measure the inside and outside outline of workpiece without contacting the workpiece's surface to realize numeric of model surface quickly and accurately. So, we can combine MPF with Laser Measurement Technology to realize the forming of 3-D sheet quickly, flexibly and accurately. The main contents and results are as follows:1) To compare with objective model to compute the shape error, we measure the workpiece lossless by laser measurement technology. The laser measurement technology, which can measure the inside and outside outline of workpiece without...