Multi-dimensional Motion Control In Flexible Roll Forming Manufacturing

As the automotive, construction and other industries raised the demand of profiles with variable cross sections, flexible roll forming technology has emerged. Compared with the more mature traditional roll forming, flexible roll forming is in the preliminary stage of research in the areas of forming mechanism, forming machine and the control system of the machine. In foreign countries such as Germany, Switzerland, France, and Japan, the developed equipment is still in the experimental stage. North China University of Technology filled the blank of domestic research on this technology.With the advantages of its low cost, high efficiency, long life, low noise and low pollution, Flexible roll forming has broad application prospects in many areas such as automotive, construction, furniture. At present, how to form the variable width, variable height and ultra high-strength steel profiles is the hot topics of research at home and abroad. First, this paper gives a brief overview of the foreign representative forming machine, studies on the control method, and then points out the machine design challenges which forms ultra high strength steel. Second, it describes a double rack and single gear structure of flexible roll forming machine developed by North China University of Technology. This machine has a compact structure, a high stiffness and applies to variable width and high-strength steel roll forming profiles.Flexible roll forming can produce the variable cross-section profiles along the longitudinal direction, therefore it needs to control the roller to do relative transverse movement and also the rollers should always be tangent to the formed flange. Three movements which are the forward movement of the sheet metal, the lateral movement and the rotation of the rollers make a final variable section profile of the product. This paper is dedicated to solving complex motion control of flexible roll forming. It gives the control algorithms of rollers and verifies the correctness of the algorithms by programming and trajectory simulation with OpenGL and VC++. Using this algorithm can produce the two-dimensional curve of profiles, and this algorithm can be integrated into an open flexible roll forming control system. Servo motors can move based on the given instructions to achieve the final forming of sheet metal.Finally, this paper focuses on the control issue of double rack and single gear mechanical structure. It solves the trajectory planning problems and allocates the displacement instruction of the two racks. By programming in VC++, it gives the interpolation points information, and then they are imported into SolidWorks simulation. The comparison result between the simulation path and the actual path can verify correctness and feasibility of this algorithm, and gives a guidance and reference of the control system.