Design Of Rolling Shear Mechanism Based On Genetic Algorithms

Rolling shear, one of important shearing equipments in the process of finishing plate,has the characteristics of complex structure, high level of automation, great technical difficulty and more ancillary equipment. At present, although rolling shear equipment has already been introduced to China, because of the limitations of technology, it is difficult to determine the scale parameter of the driving mechanism. Rolling Shear on the blade drive mechanism is a complex seven-bar mechanism with two DOF, which is considered as the studying object in this thesis. This paper designs ideal trajectory and size through improved genetic algorithms. It also provides software for engineering and technical personnel who can design rolling shear equipment rational as reference frame from the result of this software in the paper.When the rolling shear determined by the cutting width and cutting thickness achieves pure rolling, trajectory of certain points on the up blade is the ideal trajectory, and trajectory achieved by the planar seven-bar mechanism on the blade is the actual trajectory. By designing the size parameters, errors of the corresponding point on the blade between the actual trajectory and ideal trajectory is the minimum. This paper takes each bar length as variables to establish a mathematical model of the optimized design.In this paper, the bar length of the rolling shear mechanism is obtained by using simple genetic algorithm and improved genetic algorithm separately, considering bars and angles as design variables, establishing the object function to get optimum solution by the minimum error between the actual trajectory and ideal trajectory. Simple genetic algorithm has been researched deeply and the defects have been analyzed. An improved genetic algorithm on the basis of gray encoding is presented according to premature convergence and low search efficiency and poor convergence accuracy of simple genetic algorithm, which has improved based on optimum maintenance of simple genetic algorithm and performs selected operator combination with fitness proportional model. The algorithm ensures the convergence property of genetic algorithm, and prevents premature phenomenon in some extent. Optimal design of rolling shear based on improved genetic algorithm is more closer to practical application compare the results of Rolling Shear instance. Improved genetic algorithm of this paper is the issue of prematurity of genetic algorithm to provide a new way of thinking and improving engineering practice in the design of Rolling Shear equipment accuracy.In this paper,design of MATLAB’s GUI interface makes the program more easier to use for engineers. As long as the rolling shear’s original data and the bar length’s initial value are entered, each bar length can be optimized, optimization process can be observed and errors can be achieved.